Malinowski v. Sikorsky Aircraft Corp. ( 2021 )


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    RICHARD MALINOWSKI v. SIKORSKY AIRCRAFT
    CORPORATION ET AL.
    (AC 43617)
    Bright, C. J., and Alvord and Alexander, Js.
    Syllabus
    The defendants, the employer, S Co., and its insurance carrier, A Co.,
    appealed to this court from the decision of the Compensation Review
    Board, which affirmed the decision of the Worker’s Compensation Com-
    missioner finding that the plaintiff’s repetitive workplace activities at S
    Co. substantially and permanently aggravated a preexisting condition
    in his knee and denying the defendants’ motion for articulation. The
    plaintiff, who suffered from degenerative arthritis stemming from a work
    injury he suffered in 1972, and a subsequent surgery in 1973, prior
    to his employment with S Co., and who ultimately required a total
    replacement of his left knee, submitted into evidence medical records
    and correspondence from his treating physician, P. The defendants
    claimed that the board improperly affirmed the commissioner’s award
    because, inter alia, P’s expert opinions were not expressed with reason-
    able medical probability. Held:
    1. The board properly affirmed the commissioner’s award.
    a. The board properly affirmed the commissioner’s finding that P’s opin-
    ion that there was a causal relationship between the plaintiff’s employ-
    ment and his need for surgery was expressed with a reasonable degree
    of medical probability; P opined in unequivocal language that the plain-
    tiff’s 1972 injury actually had been aggravated by the plaintiff’s work at
    S Co., pulling and pushing pallets of parts weighing 800 to 1400 pounds
    for shifts of 12 hours, and, although P’s notes indicated that the plaintiff’s
    overwhelming medical issue was arthritis and that his need for surgery
    dated back to his 1973 knee operation, these references did not render
    P’s entire opinion speculative and were not inconsistent with an opinion
    that the plaintiff’s workplace activities at S Co. constituted a substantial
    contributing factor to the plaintiff’s need for surgery because they aggra-
    vated the plaintiff’s preexisting condition.
    b. The board properly affirmed the commissioner’s finding that P’s
    records constituted competent medical evidence from which the commis-
    sioner could find a causal relationship between the plaintiff’s work activi-
    ties at S Co. and his need for surgery: P’s records reported the plaintiff’s
    condition, symptoms and course of treatment and contained P’s expert
    opinion that the plaintiff’s knee injury was causally related to his work,
    and the defendants did not object to the admission of P’s records into
    evidence, nor did they depose P or call him to testify at the hearing;
    moreover, P’s opinion was not incompetent for a lack of supporting
    facts, as, although the plaintiff testified that he retrieved the heaviest,
    1400 pound fixtures only 20 to 30 times throughout the course of his
    career, P’s opinion was that pushing heavy carts of up to 1400 pounds
    during back-to-back 12 hour shifts contributed to the plaintiff’s injury;
    furthermore, P’s medical evidence was supported by other evidence,
    including the plaintiff’s extensive testimony as to his workplace activities
    pushing carts of heavy parts on a regular basis, which the commissioner
    found credible.
    c. The commissioner did not improperly refer to the plaintiff’s work
    activities beyond those expressly identified in P’s records; the commis-
    sioner had before him expert medical evidence that the plaintiff’s work
    at S Co. caused his need for surgery, thus, he was not limited to consider
    only the activities expressly identified by P but was entitled also to
    consider the plaintiff’s testimony, which in no way undermined the ade-
    quacy or competency of P’s expert opinion.
    2. The board properly affirmed the commissioner’s decision to deny the
    defendant’s request for articulation; the commissioner did not abuse his
    discretion in denying the request, as the finding for which the defendants
    sought an articulation, that the plaintiff’s workplace activities had sub-
    stantially and permanently aggravated his underlying and preexisting
    knee condition, when considered together with P’s records, reflected
    P’s opinion that the work activities aggravated the plaintiff’s underly-
    ing condition.
    Argued March 11—officially released September 7, 2021
    Procedural History
    Appeal from the decision of the Workers’ Compensa-
    tion Commissioner for the Eighth District finding that
    the plaintiff had sustained a compensable injury, award-
    ing certain disability benefits, and denying the motion
    to correct and for articulation filed by the named defen-
    dant et al., brought to the Compensation Review Board,
    which affirmed the commissioner’s decision, and the
    named defendant et al. appealed to this court. Affirmed.
    Lucas D. Strunk, with whom was Katherine E.
    Dudack, for the appellants (named defendant et al.).
    Donna Civitello, with whom was Robert F. Carter,
    for the appellee (plaintiff).
    Opinion
    ALVORD, J. The defendant Sikorsky Aircraft Corpo-
    ration1 appeals from the decision of the Compensation
    Review Board (board) affirming the decision of the
    Workers’ Compensation Commissioner for the Eighth
    District (commissioner). On appeal, the defendant
    claims that (1) the board erred in affirming the commis-
    sioner’s finding that the workplace activities of the
    plaintiff, Richard Malinowski, substantially and perma-
    nently aggravated preexisting degenerative arthritis in
    his left knee, resulting in the need for a total knee
    replacement,2 and (2) the commissioner erred in failing
    to grant its motion for articulation. We affirm the deci-
    sion of the board.
    The following history is necessary for the resolution
    of this appeal. On February 24, 2012, the plaintiff, who
    is employed by the defendant, filed a form 30C seeking
    compensation for an injury to his knees. He noted the
    date of injury as January 19, 2012, and stated that ‘‘[b]oth
    knees swelled up during the course of work that day
    . . . .’’ The hearing before the commissioner was held
    on April 30, 2015, and May 17, August 10 and November
    30, 2016. The commissioner heard the testimony of the
    plaintiff and received as exhibits, among other docu-
    ments, medical records and correspondence from Ron-
    ald S. Paret, a physician who treated the plaintiff for
    his knee injuries, the defendant’s plant medical facility
    reports, and deposition transcripts of the plaintiff,
    Christopher Lena, a physician who evaluated the plain-
    tiff at the request of the defendant, and Sebastian
    Marino, the plaintiff’s former employer.
    On June 5, 2017, the commissioner issued his findings
    and award. The commissioner summarized the plain-
    tiff’s testimony as follows. The plaintiff injured his left
    knee in 1972 while working as a motorcycle mechanic
    at S. Marino’s Honda City (Honda), and he underwent
    surgery on that knee in November, 1973. A discharge
    summary referenced a left meniscotomy surgery, and
    the plaintiff stated that he had the lateral meniscus of
    his left knee removed.3 The plaintiff began working for
    the defendant in February, 1984. He was employed with
    the job title ‘‘Grinder B’’ for twenty-seven years before
    he was promoted to ‘‘Grinder Specialist.’’
    Between the time he left employment with Honda4
    and 2012, the plaintiff did not have any medical treat-
    ment to his left knee or any other left knee injury,
    except for a laceration over his left kneecap that he
    sustained while working for a steel company. Between
    1973 and 2012, the plaintiff had occasional soreness in
    his left knee after strenuous exercise, such as running,
    swimming, and playing basketball. He did not experi-
    ence swelling.
    For twenty-eight years, while employed by the defen-
    dant, the plaintiff worked on one of two Springfield
    vertical grinders, which are the defendant’s largest
    grinders. The grinders make the main rotor parts and
    transmission housings for helicopters. The tables on
    the grinders are approximately five and one-half feet
    in diameter and they have dual cutting heads on them.
    The grinder that the plaintiff primarily operated was
    elevated by six stairs. Depending on the job, he climbed
    the stairs as often as eight times per hour. He also
    carried reference rings and gauges, which weighed
    approximately twenty-five pounds each. When the parts
    he was grinding weighed less than fifty pounds, he car-
    ried them by hand up and down the stairs.
    Over the course of the twenty-eight years he worked
    the grinder, the plaintiff was required to retrieve fix-
    tures. ‘‘The fixtures for grinding the transmission hous-
    ings on the Blackhawk were the heaviest. The original
    fixture weighed 1400 pounds, but about [10] years ago
    a new and lighter one (approx[imately] 500 pounds)
    was made. It was the grinder operator’s job to set up
    every job, which included placing the fixture on the
    grinder. In order to set up the grinder, he would have
    to get the fixture out of the fixture crib, which is about
    100 yards away from the grinder. If he couldn’t get a
    tow motor operator to get the fixture, he would need
    to do so with a pallet jack or floor jack. In [28] years
    he probably needed to get the 1400 pound part about
    20 [to] 30 times. . . . Most of the heavy fixtures were
    stored directly across the aisle from the grinder. How-
    ever, the operator would need to get a pallet jack and
    position them so that a crane would be able to lift
    them onto the grinder. Depending on the job, this could
    happen two or three times per day.’’
    It could take up to four hours to set up the machine,
    and the plaintiff spent much of that time bent over. The
    plaintiff also, at other times, would have to reach out
    to the grinding table while standing on one leg. On a
    regular basis, he would push carts containing heavy
    parts. The plaintiff lifted parts weighing sixty pounds
    or less by hand and heavier parts by crane.
    The plaintiff did not notice any knee problems until
    January, 2012, when he was lifting parts and working
    on a gear grinder. He had worked two twelve hour shifts
    and ‘‘both of his knees had blown up by the third day.’’
    The plaintiff saw Paret, who drained his left knee. In
    March, 2012, Paret recommended bilateral knee
    replacements, but the plaintiff continued working and
    hoped that his knees would get better. The plaintiff
    underwent a right total knee replacement surgery on
    October 30, 2014,5 and a left total knee replacement
    surgery on February 19, 2015.
    Although Paret did not testify at the hearing, records
    prepared by him were entered into evidence. The com-
    missioner quoted from a February 8, 2012 report pre-
    pared by Paret: ‘‘[The plaintiff] is a patient of Dr. Ross-
    Russell’s with a knee swelling. He has had three weeks
    of left-sided knee pain. Wednesday to Friday he was
    working [twelve] hours a day and had gradually increas-
    ing swelling in the knee when he was pushing large
    heavy carts and racks of gears on the floor. He had
    previously a meniscectomy many, many years ago as a
    medial meniscectomy back in 1975 with a Dr. Campbell-
    Jacobs in Middletown but in the meantime he has had
    no issues ongoing at this point.
    ‘‘IMPRESSION: This is a work injury. He previously
    does have substantial damage to the knee from a previ-
    ous injury although he has bilateral knee arthritis. At
    this point the effusion is rather significant. I believe it
    was caused by his work-related efforts pushing very
    heavy racks of gears working [twelve] hours a day for
    several days in a row. He has moderately severe degen-
    erative joint disease which has been aggravated now
    by his work-related injury.’’ (Internal quotation marks
    omitted.)
    The commissioner also noted Paret’s further opinion
    on causation as expressed in a December 16, 2012 letter.
    The commissioner stated: ‘‘[Paret] states that an open
    left-sided medial meniscectomy from [1973] and
    arthroscopic meniscectomy on the right side are both
    substantial contributing factors to the [plaintiff’s] pro-
    gressive arthritic changes regarding both knees. [Paret]
    goes on to state that the original work injury from [1972]
    at Honda has been aggravated by his working at [the
    defendant] and that the [plaintiff’s] activities involving
    the pushing and pulling of heavy pallets of engine and
    turbine parts are a substantial contributing factor in
    the aggravation of the [plaintiff’s] preexisting left knee
    condition from a [1972] injury at Honda.’’
    The deposition testimony of Lena, who evaluated the
    plaintiff at the request of the defendant, was entered
    into evidence during the hearing. The commissioner
    summarized Lena’s testimony: ‘‘A procedure such as
    the [plaintiff’s] left knee open meniscectomy leads to
    significant arthritis and total knee replacement given
    that the meniscus absorbs 70 [to] 80 [percent] of the
    weight when walking, thereby increasing the load on
    cartilage, which wears away. . . . His review of the
    [plaintiff’s] X-rays and MRI confirmed the existence of
    advanced osteoarthritis, chronic ACL deficiency and
    joint effusion consistent with old injury and surgery,
    and showing that the existence of bone on bone medial
    compartments was consistent with the prior injury and
    surgery. . . . In his opinion, the [1972] injury was a
    substantial contributing factor to the [plaintiff’s] left
    knee condition and the [plaintiff] would need a total
    knee replacement sooner because of it. Also, the [plain-
    tiff’s] work at [the defendant] was a contributing factor,
    but not a substantial contributing factor.’’
    On the basis of the testimony and documentary evi-
    dence, the commissioner made the following findings:
    ‘‘The [plaintiff] had a left knee meniscectomy on
    November 26, 1973. . . . The left knee meniscectomy
    in 1973 was a substantial contributing factor in the
    [plaintiff’s] development of arthritis. . . . The [plain-
    tiff’s] repetitive work activities of climbing up and down
    stairs while carrying heavy parts and fixtures, setting
    up a grinder while reaching and leaning on one foot,
    extensive pushing, pulling, reaching and lifting of heavy
    parts, acted in substantially and permanently aggravat-
    ing his underlying and preexisting left knee condition,
    resulting in the need for a total left knee replacement
    on February 19, 2015. . . . The [plaintiff’s] testimony
    regarding his physical condition and work activities
    was credible and persuasive. . . . The opinions of . . .
    Paret were more persuasive than those of . . . Lena,
    especially with regard to the impact of the [plaintiff’s]
    work activities on his ultimate need for left total knee
    replacement.’’6
    The commissioner ordered the defendant to reim-
    burse the plaintiff for his claimed out-of-pocket
    expenses and to pay all claimed outstanding medical
    bills for treatment of the plaintiff’s left knee. The com-
    missioner designated Paret as the authorized treating
    physician for the plaintiff’s left knee claim of January
    19, 2012.7 Following the issuance of the commissioner’s
    findings and award, the defendant filed a motion to
    correct the commissioner’s findings and request for
    articulation, which was denied.
    The defendant thereafter appealed to the board,
    claiming error in the finding and award and in the com-
    missioner’s denial of its motion to correct. On appeal to
    the board, the defendant argued that the commissioner
    erroneously determined that the plaintiff’s need for total
    left knee replacement surgery was due to repetitive
    work activities that aggravated his underlying preex-
    isting degenerative changes. The defendant argued that
    the expert opinion on which the commissioner relied
    was not based on the evidence, and the commissioner’s
    conclusions were predicated on the fact that the plain-
    tiff performed certain repetitive activities about which
    the plaintiff’s medical expert did not comment. The
    defendant also argued that the record was devoid of
    expert testimony that would serve to establish, within
    reasonable medical probability, the causal link between
    the plaintiff’s work activities and his need for left knee
    replacement surgery. Finally, the defendant argued that
    the commissioner improperly denied its motion to cor-
    rect and request for articulation.
    In an August 26, 2019 decision, the board affirmed
    the decision of the commissioner. It first addressed
    the defendant’s challenge to Paret’s opinion. The board
    referred to instances in which Paret had addressed the
    causation of the plaintiff’s left knee replacement sur-
    gery. First, it referred to Paret’s February 8, 2012 report
    of his initial visit with the plaintiff, in which Paret attrib-
    uted the swelling in the plaintiff’s knee to his having
    pushed racks of gears for twelve hours for several days
    in a row. The board noted that ‘‘Paret also opined that
    the [plaintiff’s] degenerative disease had been aggra-
    vated by the injury, but did not specifically state that
    the swelling episode caused the need for the total knee
    replacement.’’ Second, the board referenced Paret’s
    February 15, 2012 report in which he opined that the
    plaintiff suffered from severe degenerative joint disease
    in his left knee, and he noted that the ‘‘ ‘overwhelming
    issue is arthritis’ ’’ due to the meniscectomy in 1973.
    Third, the board referred to a December 16, 2012 letter
    authored by Paret, in which he noted that the plaintiff
    ‘‘ ‘has been responsible as a machinist for pulling very
    heavy loads weighing up to 1400 pounds on pull carts
    with no mechanical assistance, sometimes for fairly
    long distances of almost 100 yards.’ ’’ The board further
    noted Paret’s opinion that the plaintiff’s ‘‘ ‘original work
    injury from [1972] at Honda [was] actually aggravated
    by his working at [the defendant].’ ’’ Fourth, the board
    noted Paret’s February 6, 2015 office note, which pro-
    vided that the contemplated left total knee replacement
    ‘‘ ‘obviously dates back to his [1973] open meniscec-
    tomy.’ ’’
    The board recognized that, ‘‘[w]here . . . it is diffi-
    cult to ascertain whether or not the disease arose out
    of the employment, it is necessary to rely on expert
    medical opinion. Unless the medical testimony by itself
    establishes a causal relation, or unless it establishes a
    causal relation when it is considered along with other
    evidence, the commissioner cannot conclude that the
    disease arose out of the employment.’’ (Internal quota-
    tion marks omitted.) Murchison v. Skinner Precision
    Industries, Inc., 
    162 Conn. 142
    , 152, 
    291 A.2d 743
     (1972).
    Applying this standard, the board determined that it
    was necessary for the commissioner to rely on expert
    medical testimony to determine that the plaintiff’s left
    knee meniscectomy in 1973 was a substantial contribut-
    ing factor in his development of arthritis. Citing Garo-
    fola v. Yale & Towne Mfg. Co., 
    131 Conn. 572
    , 574, 
    41 A.2d 451
     (1945), the board stated that in the absence
    of expert testimony linking the meniscectomy with the
    development of arthritis, ‘‘ ‘[i]t could not be said to have
    been a matter of common knowledge that the symptoms
    described by the plaintiff as having occurred while
    doing his customary work were related to the injury
    . . . .’ ’’
    The board was not persuaded, however, that the same
    analysis applied to the commissioner’s conclusions as
    to the role of the plaintiff’s workplace activities in sub-
    stantially and permanently aggravating his condition,
    resulting in the need for a knee replacement. The board
    determined that, once it had been established through
    expert testimony that the plaintiff’s medical history ren-
    dered him susceptible to arthritis, it was within the
    commissioner’s discretion to infer that the plaintiff’s
    work activities ‘‘ ‘acted in substantially and perma-
    nently aggravating his underlying and preexisting left
    knee condition, resulting in the need for a total left
    knee replacement . . . .’ ’’
    The board noted that the commissioner had before
    him the extensive testimony of the plaintiff. The board
    further considered the lack of any evidence in the
    record that any other activity might have contributed
    to the plaintiff’s knee deterioration or that the plaintiff
    had experienced any significant medical issues with his
    left knee prior to January, 2012. The board determined
    that the commissioner reasonably could have inferred
    ‘‘ ‘that it was much more likely that the [injury] occurred
    from the work in which the plaintiff was engaged, aris-
    ing, as it did, during performance of the work, than that
    it occurred from some unknown cause.’ ’’ See Garofola
    v. Yale & Towne Mfg. Co., 
    supra,
     
    131 Conn. 574
    .
    The board next turned to the medical record, stating
    that it was ‘‘not devoid of support for the commission-
    er’s conclusions relative to the role played by the [plain-
    tiff’s] repetitive workplace activities.’’ Specifically, the
    board stated that both Lena and Paret agreed that the
    plaintiff’s prior injury in 1972 and meniscectomy in 1973
    ‘‘contributed to the deterioration of the [plaintiff’s] left
    knee over time and his eventual need for a total knee
    replacement.’’ The board acknowledged that Paret’s
    opinion with respect to the role of the plaintiff’s work
    activities ‘‘does appear to be primarily based on his
    understanding that the [plaintiff] was responsible for
    pushing and pulling heavy fixtures.’’ It then explained
    that Lena’s deposition testimony was ambiguous as to
    the role the plaintiff’s work activities played in contrib-
    uting to the deterioration. The board restated Lena’s
    testimony that the plaintiff’s employment was a ‘‘ ‘con-
    tributing factor, but I don’t think it’s a substantial con-
    tributing factor.’ ’’ The board restated Lena’s testimony:
    ‘‘ ‘Is there any contributing factor from his occupation?
    Absolutely. But it is certainly not the main or substantial
    contributing factor to it.’ ’’ When asked whether the
    plaintiff’s predisposition accelerated the knee deterio-
    ration in light of his workplace activities, Lena
    answered: ‘‘It is possible especially if there is a signifi-
    cant exciting event.’’ Finally, when asked whether
    ‘‘being on your feet, walking and pushing and pulling
    heavy loads for a job for eight hours a day’’ played a
    role in the plaintiff’s knee deterioration, he responded:
    ‘‘I’m actually impressed that he made it as long as he
    did.’’
    The board stated that the determination of what con-
    stitutes a substantial contributing factor is a question
    for the commissioner, who was not required to accept
    Lena’s opinion. Moreover, the board stated that ‘‘it could
    be argued that Lena’s opinion actually provided a basis,
    albeit limited, for the commissioner’s conclusion that
    the claimant’s repetitive workplace activities did play
    a role in the development of the claimant’s arthritis and
    eventual need for knee replacement surgery.’’ Ulti-
    mately, the board concluded that the commissioner
    retained the discretion to make the determination
    regarding the plaintiff’s repetitive workplace activities,
    ‘‘despite some limitations in the medical evidence rela-
    tive to that particular issue.’’
    Lastly, the board rejected the defendant’s claim that
    the commissioner erred in denying its motion to correct
    and request for articulation. Accordingly, the board
    affirmed the findings and orders of the commissioner.
    Thereafter, the defendant filed a motion for reconsider-
    ation and reargument, which the board denied. This
    appeal followed.
    ‘‘As a preliminary matter, we note that when the deci-
    sion of a commissioner is appealed to the [board], the
    [board] is obligated to hear the appeal on the record
    of the hearing before the commissioner and not to retry
    the facts. . . . It is the power and the duty of the com-
    missioner, as the trier of fact, to determine the facts.
    . . . [T]he commissioner is the sole arbiter of the
    weight of the evidence and the credibility of witnesses
    . . . . Neither the . . . board nor this court has the
    power to retry facts. . . .
    ‘‘The [board] may not disturb the conclusions that
    the commissioner draws from the facts found unless
    they result from an incorrect application of the law to
    the subordinate facts or from an inference illegally or
    unreasonably drawn from them. . . . In other words,
    [t]hese conclusions must stand unless they could not
    reasonably or logically be reached on the subordinate
    facts. . . . Our scope of review of the actions of the
    [board] is similarly limited. . . . The decision of the
    [board] must be correct in law, and must not include
    facts found without evidence or fail to include material
    facts which are admitted or undisputed.’’ (Citations
    omitted; internal quotation marks omitted.) O’Connor
    v. Med-Center Home Health Care, Inc., 
    140 Conn. App. 542
    , 547–48, 
    59 A.3d 385
    , cert. denied, 
    308 Conn. 942
    ,
    
    66 A.3d 884
     (2013).
    I
    We first address the defendant’s claim that the board
    erred in affirming the commissioner’s finding that the
    plaintiff’s need for a left total knee replacement was
    due to repetitive work activities that substantially and
    permanently aggravated the underlying preexisting
    degenerative changes in his knee. The defendant pre-
    sents three principal arguments in support of its claim
    that the plaintiff failed to prove a causal relationship
    between his employment and his need for surgery. First,
    it argues that Paret’s opinions were not expressed with
    reasonable medical probability. Second, it argues that
    ‘‘there is no competent medical opinion in the record
    tied to the plaintiff’s actual job duties,’’ where Paret’s
    opinion incorrectly assumed that the pulling of 800 to
    1400 pound parts was performed on a regular basis.
    Third, it contends that the commissioner improperly
    referenced work activities of the plaintiff that were not
    commented on by Paret. We examine each argument
    in turn.
    Our review of the record reveals that the following
    evidence was presented before the commissioner. The
    plaintiff introduced office notes, reports, and corre-
    spondence, collectively records, authored by his treat-
    ing physician, Paret. On February 8, 2012, Paret, follow-
    ing his initial meeting with the plaintiff, noted that the
    plaintiff had developed bilateral knee effusion and
    stated: ‘‘This is a work injury. He previously does have
    substantial damage to the knee from a previous injury
    although he has bilateral knee arthritis. At this point
    the effusion is rather significant. I believe it was caused
    by his work-related efforts pushing very heavy racks
    of gears working [twelve] hours a day for several days
    in a row. He has moderately severe degenerative joint
    disease which has been aggravated now by his work-
    related injury.’’ In his February 15, 2012 office note,
    Paret stated that the MRI showed that the plaintiff
    ‘‘really does have bone-on-bone.’’ Paret continued:
    ‘‘There is some edema in the subchondral region partic-
    ularly of the proximal tibial plateau and at this point
    although he does have significant meniscal tears, I
    believe his overwhelming issue is the arthritis.’’ Paret
    diagnosed the plaintiff with ‘‘severe degenerative joint
    disease.’’ He stated that ‘‘[a]pparently his original
    medial meniscectomy stemmed from a work injury
    which he is in the process of reactivating at this point
    and apparently does have an attorney involved in this
    situation. It is my opinion that if that medial meniscus
    was actually related to a [workers’ compensation] injury
    then clearly this arthritis [is] secondary to a [w]orker’s
    [c]ompensation episode.’’ In a March 14, 2012 office
    note, Paret recorded his impression that the plaintiff has
    ‘‘a large effusion likely secondary to his rather severe
    degenerative arthritis.’’ The note stated that the plaintiff
    was ‘‘considering surgical options of a total knee
    replacement as I think there is very little else that we
    can offer other than the very conservative management
    treatment course which has been ineffective so far.’’
    In his March 19, 2012 office note, Paret recorded his
    impression that the plaintiff ‘‘has a huge effusion and
    a moderately severe degenerative arthritis as well as
    [X]-rays indicating medial joint line closure.’’ Paret
    noted his recommendation of a knee replacement and
    stated that the plaintiff was due to return in July, at
    which time Paret believed there would be ‘‘no further
    ability to prescribe narcotic agents as a long-term solu-
    tion to knee degenerative joint disease.’’ In a July 13,
    2012 office note, Paret recorded the plaintiff’s chief
    complaint as ‘‘[b]ilateral knee degenerative joint dis-
    ease,’’ indicated ‘‘extreme tenderness’’ in the plaintiff’s
    left knee, and stated that ‘‘[r]eview of the [X]-rays show
    moderately severe degenerative arthritis.’’ In an August
    21, 2012 office note, Paret recorded the plaintiff’s chief
    complaint as ‘‘[k]nee pain on the left side.’’ Paret stated
    that the plaintiff ‘‘had a [work-related] injury and [is]
    still having significant issues with both lower extremit-
    ies which are both work injuries.’’ Paret recorded his
    impression of ‘‘[b]ilateral knee degenerative joint dis-
    ease’’ and stated that the plaintiff was ‘‘considering
    timing of a total knee replacement which is believed
    will be his ultimate solution for his current situation,
    pain and his [workers’ compensation] injury.’’ In a
    November 27, 2012 office note, Paret wrote that ‘‘[t]here
    is a definite medial joint line narrowing, tenderness
    and osteophytes are palpable underneath of the skin.’’
    Paret’s recommendation stated: ‘‘With bilateral knee
    degenerative joint disease . . . that he has elected at
    this point to pursue the avenue of a total knee replace-
    ment . . . .’’
    The commissioner also had before him Lena’s medi-
    cal report dated August 1, 2012. Lena described the
    plaintiff as having ‘‘a long-standing history of problems
    with his knee’’ and stated that the plaintiff ‘‘had prior
    left knee surgery done in 1973 during which he had a
    large open incision and an open medial meniscectomy.’’
    Lena recorded the plaintiff’s description of an incident
    ‘‘that occurred on [January 19, 2012] where his knee
    appeared to just swell up on him. He describes a swell-
    ing of both the left and right knee after two [twelve] hour
    shifts at work. He notes that his work as a machinist
    was very demanding on his knees especially as his age
    advanced. He describes having to pull heavy objects,
    bending over, kneeling often. He describes having to
    push large heavy carts and racks of gears on the floor.’’
    Lena stated: ‘‘After the described injury date of [January
    19, 2012], he did follow up with Dr. Ronald Paret, who
    felt that it was a work-related injury, that although he
    did have significant damage to the knee from previous
    injury, he felt that this was an aggravation of his underly-
    ing condition.’’ Lena reported that an MRI revealed,
    inter alia, ‘‘advanced tricompartmental osteoarthritis
    [and] large joint effusion . . . .’’ Lena’s assessment was
    that the plaintiff’s open meniscectomy in 1973 on the
    left side and the arthroscopic meniscectomy in 1985
    were ‘‘significant contributing factors to his progressive
    arthritic changes in the knees and his need for knee
    replacements . . . .’’ Lena stated: ‘‘The right one I do
    believe is related [to] a work-related injury specifically
    the 1985 injury during which the meniscus was removed
    which has led to progressive deterioration and arthritic
    changes that he is currently experiencing, and the left
    one related to 1973 incident with an open medial menis-
    cectomy the predication for a progression of arthritic
    changes, is he has progressed as one would expect to
    his bone-on-bone contact.’’ Lena concluded: ‘‘I believe
    that the previous meniscectomies were the substantial
    contributing factor to his development for arthritic
    changes and has led to the chronic degenerative
    changes that he currently has and that is the major
    cause for the need for the knee replacement and not
    the pushing and pulling from January of 2012.’’
    In a letter dated December 16, 2012, Paret responded
    to Lena’s evaluation and offered his own opinions. Paret
    stated that the plaintiff ‘‘has been responsible as a
    machinist [for the defendant] for pulling very heavy
    loads weighing up to 1400 pounds on pull carts with
    no mechanical assistance, sometimes for fairly long
    distances of almost 100 yards.’’ He further described
    the plaintiff’s work activities as ‘‘heavy pulling and push-
    ing of pallets of engine and turbine parts weighing 800
    to 1400 pounds . . . .’’ Paret explained that the ‘‘open
    left-sided medial meniscectomy from 1973 and arthros-
    copic meniscectomy on the right side . . . both are
    significant contributing factors to his progressive
    arthritic changes of his knee on both sides.’’ He offered
    his opinion that the plaintiff’s ‘‘original work injury from
    [1972] . . . has been actually aggravated by’’ his work-
    ing at the defendant, stating that ‘‘I believe that this is
    a work injury not wholly and exclusively related to [the
    defendant].’’ Paret stated his opinion that both knees
    are ‘‘work-related,’’ with the left knee ‘‘related to a
    Honda [workers’ compensation] injury and then subse-
    quent aggravation working’’ at the defendant. Paret con-
    cluded by stating: ‘‘It is in my opinion illogical to opine
    that the 1985 injury at [the defendant] and subsequent
    pulling and pushing activities are a contributing factor
    to his right-sided knee issue but that the same pulling
    and pushing is not related to his left knee degenerative
    arthritis which did start as a workers’ compensation
    injury for Honda . . . .’’
    In a January 22, 2013 office note, Paret stated that
    ‘‘[e]xamination of both knees shows significant degen-
    erative arthritic changes’’ and noted that the left knee
    had ‘‘a moderately severe effusion today.’’ In a February
    7, 2014 office note, Paret stated that the plaintiff had
    experienced ‘‘two weeks of significant increasing pain
    where he indicates he has ‘a complete breakdown’ of his
    knees.’’ Paret stated that ‘‘[p]revious [X]-rays indicate
    severe bilateral degenerative changes of his knees. His
    left is much more severe than the right. . . . [A]t this
    point in time he has elected a total joint replacement
    . . . .’’
    In an April 4, 2014 office note, Paret stated that the
    plaintiff had ‘‘failed nonsteroidal anti-inflammatory
    agents of three different varieties’’ and is pursuing a
    total knee replacement. He noted that the plaintiff ‘‘is
    unable to pursue his normal and usual activities because
    of his rather severe degenerative changes in both
    knees.’’ In a February 6, 2015 office note, which was
    subsequent to the plaintiff’s right knee replacement,
    Paret stated that ‘‘[h]is persisting issue is his left knee
    which is also due to a [w]orkers’ [compensation] epi-
    sode with AIG dating back to 1972 and he is having at
    least as much difficulty, if not more, on the left now
    than he is on the right.’’ Paret stated that ‘‘X-rays of the
    left knee show severe degenerative arthritis of this left
    knee, particularly medial joint line and patellofemoral
    articular surface with osteophytes throughout the
    knee.’’ Paret stated that the plaintiff was ‘‘strongly con-
    sidering surgical intervention as soon as possible which
    in my opinion obviously dates back to his [1973] open
    meniscectomy and [w]orkers’ [c]ompensation injury
    also at AIG as previously mentioned, which apparently
    surgery was done by Dr. Richard Campbell-Jacobs.’’
    The commissioner also had before him Lena’s deposi-
    tion testimony. Lena testified as to the general conse-
    quences of a complete meniscectomy, stating that it
    normally leads to the need for a total knee replacement.
    He testified that if he were giving a rating following a
    meniscectomy, he would ‘‘include in the rating the fact
    that the patient would in their lifetime require a knee
    replacement at an earlier time frame secondary to the
    injury and subsequent complete meniscectomy.’’
    When asked whether the plaintiff related to Lena any
    specific injuries following the 1972 and 1985 incidents,
    Lena replied that the plaintiff ‘‘denie[d] any other issues
    except for the [January 19, 2012 incident] where he just
    had increased swelling in the knee after working twelve
    hour shifts.’’ Lena testified that the plaintiff was a candi-
    date for knee replacement. He explained that he looks
    at the radiographic parameters to see whether someone
    is a candidate for a knee replacement, and noted that
    ‘‘[s]ome people with this much arthritis have no pain
    and you get the X-rays and you’re very surprised that
    they have no discomfort.’’8 Lena testified that his physi-
    cal examination of the plaintiff revealed the ‘‘palpable
    osteophytes, some swelling inside his knee, 2+ effusion
    on the left hand side, crepitation, which is when you
    wear through the lamina splendens you get grinding in
    the knee. And so it was basically an arthritic knee.’’
    When asked whether the injury the plaintiff sustained
    in 1972, was a substantial contributing factor in the
    plaintiff’s current condition, Lena responded: ‘‘Yes. I
    believe the total meniscectomy that he had in 1973, at
    that point in time, if I did a rating on his knee, it would
    have indicated that in his lifetime he would get a knee
    replacement at an earlier stage than if he did not have
    that injury.’’ He further testified that if the plaintiff ‘‘did
    not have the [1972] injury and he worked a couple
    twelve hour shifts at [the defendant] in 2012, I do not
    think he would have the same arthritic changes nor a
    need for knee replacement.’’ He concluded that the
    plaintiff’s work at [the defendant] was ‘‘a contributing
    factor, but . . . [not] a substantial contributing factor.
    I think the substantial contributing factor is the
    [1972] injury.’’
    When asked whether Paret believed that the plain-
    tiff’s work activities were a substantial contributing
    factor in the plaintiff’s need for total knee replacement,
    Lena testified: ‘‘He’s kind of going back and forth a little
    bit about it. If he’s going to say that, then he would say
    that anyone in [the plaintiff’s] position would therefore
    get a knee replacement if they’re employed there for
    the same amount of time. . . . That’s why when I say
    if someone gets a total meniscectomy, I guarantee that
    they’ll get a knee replacement in the earlier stage. I
    anticipate that there are other people employed by [the
    defendant] in his position that are not getting knee
    replacements. So, for that to be the substantial contrib-
    uting factor I don’t think is correct.’’ He summarized:
    ‘‘Is there any contributing factor from his occupation?
    Absolutely. But it is certainly not the main or substantial
    contributing factor to it.’’
    When asked whether the plaintiff’s work accelerated
    his need for a knee replacement, Lena stated that ‘‘[i]t
    is possible especially if there is a significant exciting
    event.’’ He further stated that he was ‘‘actually impres-
    sed that he made it as long as he did. Because after the
    [1973] meniscectomy, I would have expected severe
    arthritis within ten years, and I guarantee he had it. But
    he lived with it and he still continues to live with it.’’
    In response to a question as to whether he agreed with
    Paret, Lena testified: ‘‘It’s pretty close. He seems to feel
    that the significant contributing factor is just the work in
    between the work at [the defendant]. What he’s saying
    is that anyone in his position will get knee replacements
    period. When you hire someone you put money aside
    for knee replacements, and I disagree with that.’’
    The commissioner also had before him the plaintiff’s
    testimony, both during his deposition, taken in 2012,
    and at the hearing, held in 2015. The plaintiff testified
    as to his injury in 1972, and surgery in 1973. He testified
    that, following his surgery, he occasionally had soreness
    in his left knee but no swelling until January, 2012. The
    plaintiff testified to his work activities at the defendant.
    Specifically, during his deposition, he described his
    work for twenty-six years on the Springfield grinder,
    in which position he was responsible for ‘‘cutting what-
    ever parts they needed to be cut.’’ The plaintiff
    explained the process for retrieving fixtures, which
    served as a base for the part. The fixtures were changed
    for every job. The plaintiff described the fixtures as
    weighing between 500 and 1400 pounds.9 He was
    responsible for retrieving the fixtures from a fixture
    crib located approximately 100 yards away. He testified:
    ‘‘If we couldn’t get a tow motor operator to get it, we
    would go up there with a pallet jack or a floor jack and
    lift it up and bring it down to the machine, you know,
    pull it down, so.’’ The plaintiff explained that the pallet
    jack, alternatively called a floor jack, pump jack, or
    hand truck, is a hydraulic jack that you pump with your
    foot. The plaintiff stated that he moved the 1400 pound
    fixture approximately 20 to 30 times during his career.
    With respect to the lighter fixtures, the plaintiff testified
    that, ‘‘once we got them down, we’d store them across
    the aisle so we wouldn’t have to move them or nobody
    would have to get them. But in order to set up the job
    you would have to get a pallet jack and go get the
    fixture which was across the aisle because the crane
    couldn’t get to that position to lift up the fixture.’’ He
    testified that he would get the fixture from across the
    aisle every day, sometimes two or three times per day
    depending on the jobs to be performed. He explained
    the process of moving the fixture into place for the
    crane to pick it up and then setting up the machine,
    including putting the fixture in and loading the part.
    With respect to the parts, the plaintiff testified in his
    deposition that ‘‘the parts would go [800 to 900]
    pounds,’’ and that he would bring the part in ‘‘on a hand
    truck, put that in the aisle, unload that, climb up six
    . . . stairs, load that up onto the fixture, and adjust
    everything on the machine, guards and stuff, and set
    up and make the cut.’’ The plaintiff confirmed that he
    moved parts weighing 600 to 700 pounds by himself
    using just a hand truck, which he described as a pal-
    let jack.
    The plaintiff testified before the commissioner that
    his work in the gear room was a ‘‘physically demanding
    job.’’ He was responsible for pushing racks of gears
    weighing 800 pounds from one room to another, approx-
    imately 100 yards distance. The plaintiff also explained
    his work with a blank checker, which he described as
    an approximately 1000 pound tool used to measure
    gears. He testified that because the wheels on the blank
    checker were too small and had flat spots on them, he
    had to exert himself to get the blank checker moving.
    He explained that he did have help to move the blank
    checker and that he also would help other people push
    the blank checker. Overall, the plaintiff explained that
    his work in the gear room was physically lighter than
    his work on the Springfield grinder.
    The plaintiff described the incident in January, 2012,
    that led to his knees swelling. He testified in his deposi-
    tion that he had been ‘‘moving gears from one gear
    room to the large gear cell. Just over the course of the
    night, the second night . . . both of my knees swelled
    up, blown up. I moved a blank checker that checks
    gears out of the way, moved that from one room to
    another. Doesn’t roll very easily. It generally takes two
    people, but I guess I was feeling good. You know, you
    only get the burning sensation in your knee, you don’t
    get the extreme pain. Moving large stacks of gears
    around so I could get gears to my machine to set them
    up and run. But by the end of—started working the
    [twelve hour] day on Wednesday . . . [b]y the end of
    Thursday night, both of my knees were swollen up.’’
    He testified that he went to see Paret on February 8,
    2012, and Paret drained his left knee. When asked
    whether Paret told the plaintiff that the overwhelming
    issue was arthritis in his knees, the plaintiff responded
    that Paret ‘‘explained to me that it was a bone on bone
    contact on both knees.’’
    Having received the foregoing evidence, the commis-
    sioner made the following findings: ‘‘The [plaintiff] had
    a left knee meniscectomy on November 26, 1973. . . .
    The left knee meniscectomy in 1973 was a substantial
    contributing factor in the [plaintiff’s] development of
    arthritis. . . . The [plaintiff’s] repetitive work activities
    of climbing up and down stairs while carrying heavy
    parts and fixtures, setting up a grinder while reaching
    and leaning on one foot, extensive pushing, pulling,
    reaching and lifting of heavy parts, acted in substantially
    and permanently aggravating his underlying and preex-
    isting left knee condition, resulting in the need for a
    total left knee replacement on February 19, 2015. . . .
    The [plaintiff’s] testimony regarding his physical condi-
    tion and work activities was credible and persuasive.
    . . . The opinions of . . . Paret were more persuasive
    than those of . . . Lena, especially with regard to the
    impact of the [plaintiff’s] work activities on his ultimate
    need for left total knee replacement.’’
    In its decision following the defendant’s appeal, the
    board first stated that it was not persuaded that it was
    necessary for the commissioner to rely on expert opin-
    ion in order to determine that the plaintiff’s workplace
    activities had substantially and permanently aggravated
    his left knee condition, and it performed an analysis
    under Garofola v. Yale & Towne Mfg. Co., 
    supra,
     
    131 Conn. 574
    . See footnote 2 of this opinion. However, the
    board also stated that ‘‘the medical record is not devoid
    of support for the commissioner’s conclusions relative
    to the role played by the [plaintiff’s] repetitive work-
    place activities.’’ It ultimately described the record as
    reflecting ‘‘some limitations in the medical evidence
    relevant to that particular issue.’’
    A
    In support of its claim on appeal that the board erred
    in affirming the commissioner’s finding that the need
    for the plaintiff’s knee replacement was due to repeti-
    tive work activities, the defendant first argues that Par-
    et’s opinions were not expressed with reasonable medi-
    cal probability. The plaintiff responds that ‘‘Paret’s
    opinion that the repetitive trauma caused by the plain-
    tiff’s work for the defendant, in the setting of prior
    bilateral meniscectomies, was a significant contributing
    factor to the need for arthroplasty for both knees was
    expressed with certainty, without expressions of con-
    jecture or speculation.’’ We agree with the plaintiff.
    We first discuss the general requirement of causation
    in workers’ compensation cases. ‘‘To recover under the
    [Workers’ Compensation Act, General Statutes § 31-275
    et seq.], an employee must meet the two part test
    embodied in . . . § 31-275, namely, that the injury
    claimed arose out of the employee’s employment and
    occurred in the course of the employment. . . . [I]n
    Connecticut traditional concepts of proximate cause
    constitute the rule for determining . . . causation [in
    a workers’ compensation case]. . . . An actual cause
    that is a substantial factor in the resulting harm is a
    proximate cause of that harm. . . . The finding of
    actual cause is thus a requisite for any finding of proxi-
    mate cause.’’ (Citation omitted; internal quotation
    marks omitted.) Marandino v. Prometheus Pharmacy,
    
    294 Conn. 564
    , 591, 
    986 A.2d 1023
     (2010). ‘‘[T]he deter-
    mination of whether the substantial factor test has been
    satisfied is a question of fact. . . . If reasonable minds
    can disagree as to whether the [claimant] has satisfied
    her burden of establishing proximate cause . . . we
    will not disturb the commissioner’s finding even if we
    might reach a different conclusion.’’ (Citation omitted;
    internal quotation marks omitted.) Wilson v. Maefair
    Health Care Centers, 
    155 Conn. App. 345
    , 355, 
    109 A.3d 947
     (2015).
    For expert medical opinion to be admissible in estab-
    lishing causation, it must be based on reasonable proba-
    bilities. In Struckman v. Burns, 
    205 Conn. 542
    , 554–55,
    
    534 A.2d 888
     (1987), our Supreme Court rejected the
    proposition that an expert must use certain formulaic
    words to state an opinion and explained: ‘‘Expert opin-
    ions must be based upon reasonable probabilities rather
    than mere speculation or conjecture if they are to be
    admissible in establishing causation. . . . To be rea-
    sonably probable, a conclusion must be more likely
    than not. . . . Whether an expert’s testimony is
    expressed in terms of a reasonable probability that an
    event has occurred does not depend upon the semantics
    of the expert or his use of any particular term or phrase,
    but rather, is determined by looking at the entire sub-
    stance of the expert’s testimony. . . . When reports
    are the substitute for testimony, the entire report should
    be examined, not only certain phrases or words.’’ (Cita-
    tions omitted.)
    Considering Paret’s records as a whole, we agree with
    the plaintiff that his opinion was based on a reasonable
    probability. Paret’s opinion is most succinctly stated in
    his December 16, 2012 letter, referenced by the commis-
    sioner in his findings, responding to Lena’s examination.
    Lena had concluded that the plaintiff’s need for a left
    knee replacement was related to the 1973 open medial
    meniscectomy. Specifically, Lena concluded that ‘‘the
    previously meniscectomies were the substantial con-
    tributing factor to his development for arthritic changes
    and has led to the chronic degenerative changes that
    he currently has and that is the major cause for the
    need for the knee replacement and not the pushing and
    pulling from January of 2012.’’ Paret responded that
    the plaintiff’s original work injury from 1972 ‘‘has been
    actually aggravated by his working at [the defendant].’’
    He described the plaintiff’s work as ‘‘subsequent heavy
    pulling and pushing of pallets of engine and turbine
    parts weighing 800 to 1400 pounds,’’ explaining that
    such work was a significant contributing factor to the
    plaintiff’s right knee injuries.10 He then remarked that
    it was illogical to opine that the pulling and pushing
    activities were a ‘‘contributing factor’’ to his right knee
    injury but that the ‘‘same pulling and pushing is not
    related to his left knee degenerative arthritis . . . .’’11
    Other of Paret’s notes reflect his opinion as to the con-
    nection between the plaintiff’s workplace activities and
    the aggravation of his arthritis. For example, on Febru-
    ary 8, 2012, Paret wrote, in an office note also referenced
    by the commissioner in his findings, that the plaintiff’s
    ‘‘moderately severe degenerative joint disease’’ had
    been ‘‘aggravated now by his work-related injury,’’ and
    referenced the twelve hour days pushing racks of gears.
    Thus, we are satisfied that his opinion was based on a
    reasonable probability.
    The defendant points to two notations in Paret’s
    records that were not referenced by the commissioner
    in his findings. First, it cites Paret’s February 15, 2012
    notation: ‘‘[A]lthough [the plaintiff] does have signifi-
    cant meniscal tears, I believe his overwhelming issue
    is the arthritis.’’ Second, it cites Paret’s February 6,
    2015 notation: ‘‘[The plaintiff] is, at this point, strongly
    considering surgical intervention [on his left knee] as
    soon as possible which in my opinion obviously dates
    back to his [1973] open meniscectomy . . . .’’
    We are not persuaded that Paret’s references to
    arthritis as the ‘‘overwhelming issue’’ and the plaintiff’s
    need for surgery as dating back to the meniscectomy
    render his entire opinion speculative. More specifically,
    Paret’s references to the plaintiff’s meniscectomy and
    resulting arthritis are not inconsistent with an opinion
    that his workplace activities constituted a substantial
    contributing factor to the plaintiff’s need for surgery
    because they aggravated the plaintiff’s preexisting con-
    dition. ‘‘It is well established that an employer takes
    the employee in the state of health in which it finds the
    employee. . . . [A]n injury received in the course of
    the employment does not cease to be one arising out
    of the employment merely because some infirmity due
    to disease has originally set in action the final and
    proximate cause of the injury. . . . If the injury is the
    cause of the disability, it is compensable even though
    such an injury might not have caused the disability if
    occurring to a healthy employee or even an average
    employee.’’ (Citation omitted; internal quotation marks
    omitted.) Wilson v. Maefair Health Care Centers, supra,
    
    155 Conn. App. 356
     n.9.
    The defendant relies on the decision of the board in
    Ivan-Marrotte v. State, No. 3599, CRB 02-97-04 (July
    28, 1998), which is distinguishable from the present
    case. In Ivan-Marrotte, the plaintiff was in the course
    of her employment when she chased a group home
    client over a wall and landed on her left leg. She later
    claimed that she developed right leg problems as a
    result of the left leg injury. The commissioner con-
    cluded that the plaintiff’s phlebitis in her right leg was
    caused by the injury to her left leg. The board reversed
    the decision of the commissioner, finding it unsup-
    ported by the medical evidence. The board noted that
    the doctor who offered an opinion on the plaintiff’s
    condition had testified during his deposition that ‘‘there
    certainly is a lot of room for speculation’’ as to what
    led up to the plaintiff’s right leg symptoms, conceded
    that reasonable doctors trained in vascular conditions
    might disagree on the medical cause of the plaintiff’s
    right leg symptoms, and stated that ‘‘[i]t would be very
    difficult to tell’’ whether jumping off the wall caused
    the plaintiff’s right leg symptoms. In contrast with the
    expert’s testimony in Ivan-Marrotte, Paret’s opinion in
    the present case lacked the equivocal language of an
    opinion improperly based on speculation and conjec-
    ture. Indeed, Paret opined that the plaintiff’s original
    work injury from 1972 ‘‘has been actually aggravated
    by his working at [the defendant].’’
    The defendant argues that ‘‘[t]he only medical opinion
    in the record that was expressed with reasonable medi-
    cal probability was . . . Lena, who was of the opinion
    that [the] plaintiff’s work activities were not a substan-
    tial contributing factor in permanently aggravating [the]
    plaintiff’s degenerative disease.’’ (Emphasis omitted.)
    The commissioner, however, found Paret’s opinion
    more credible and persuasive than that of Lena. It is
    well established that ‘‘[i]t is the quintessential function
    of the finder of fact to reject or accept evidence and
    to believe or disbelieve any expert testimony. . . . The
    trier may accept or reject, in whole or in part, the
    testimony of an expert.’’ (Internal quotation marks omit-
    ted.) Chesler v. Derby, 
    96 Conn. App. 207
    , 218, 
    899 A.2d 624
    , cert. denied, 
    280 Conn. 909
    , 
    907 A.2d 88
     (2006).
    Accordingly, we conclude that Paret’s opinion that
    there was a causal relationship between the plaintiff’s
    employment and his need for surgery was expressed
    within a reasonable degree of medical probability.
    B
    The defendant next argues that the commissioner’s
    causation finding was not supported by competent med-
    ical evidence because Paret incorrectly assumed that
    the pulling of 800 to 1400 pound parts was performed
    on a regular basis. We disagree.
    The following additional facts are relevant. Paret, in
    his December 16, 2012 letter, described the plaintiff’s
    work activities as ‘‘heavy pulling and pushing of pallets
    of engine and turbine parts weighing 800 to 1400
    pounds.’’ Paret also stated, in that same correspon-
    dence, that the plaintiff ‘‘has been responsible as a
    machinist [for the defendant] for pulling very heavy
    loads weighing up to 1400 pounds on pull carts with
    no mechanical assistance, sometimes for fairly long
    distances of almost 100 yards.’’12 The commissioner, in
    his findings, referenced the plaintiff’s testimony that he
    retrieved the 1400 pound part approximately 20 to 30
    times in his career and that when he could not get a
    tow motor operator to get the fixture, he would need to
    do so with a pallet jack or floor jack. The commissioner
    further referenced the plaintiff’s testimony regarding
    his retrieval of the fixtures stored across the aisle from
    the grinder. Depending on the job, he would need to
    retrieve the part two or three times per day and use a
    pallet jack to position the fixture so that a crane could
    lift it onto the grinder. The commissioner found the
    plaintiff’s testimony regarding his work activities credi-
    ble and persuasive.
    In reviewing the defendant’s argument, we consider
    our Supreme Court’s decision in Marandino v. Pro-
    metheus Pharmacy, 
    supra,
     
    294 Conn. 588
    , instructive.
    In Marandino, our Supreme Court considered whether
    the commissioner properly relied on a medical report
    from the plaintiff’s attending physician in determining
    that the plaintiff’s knee injury was compensable. The
    defendant had contended that the report was not sup-
    ported by competent evidence on which the commis-
    sioner could rely. 
    Id.
     The report stated the opinion of
    the plaintiff’s attending physician that the plaintiff’s
    knee injury, which she sustained while falling down the
    stairs at her home, was caused by a previous, work-
    related arm injury. 
    Id.,
     569–70, 588. Specifically, the
    record contained an April, 2002 letter authored by the
    plaintiff’s attending physician that provided: ‘‘I am
    responding to your . . . correspondence regarding
    your client and my patient, [the plaintiff]. Please be
    advised that we have recommended surgery and this
    dates back to [February, 2002]. I talked specifically with
    the [plaintiff] that she had an osteochondral lesion [in
    her knee]. This is a direct result of her previous work-
    related trauma and as such is a continuation of her
    ongoing problems. This does not represent a new condi-
    tion.’’13 (Emphasis omitted; internal quotation marks
    omitted.) Id., 588. The commissioner determined that
    the attending physician had reported that the knee
    injury was caused by the arm injury and found such
    report, which was uncontradicted, persuasive. Id., 589–
    90.
    On appeal, this court determined that the expert med-
    ical evidence in the record was not competent, in that
    it was grounded in speculation and conjecture. Maran-
    dino v. Prometheus Pharmacy, 
    105 Conn. App. 669
    ,
    680, 
    939 A.2d 591
     (2008), rev’d in part, 
    294 Conn. 564
    ,
    
    986 A.2d 1023
     (2010). Specifically, this court stated that
    there was nothing in the attending physician’s reports
    ‘‘to suggest that the arm injury, rather than some other
    source, was a substantial factor in bringing about the
    knee injury’’; id.; and that the physician’s opinion
    regarding causation was ‘‘merely a statement devoid of
    a basis in fact . . . .’’ 
    Id., 681
    .
    Our Supreme Court reversed in part the judgment of
    this court, concluding that the attending physician’s
    expert opinion was competent despite his failure to
    include supporting medical facts. Marandino v. Pro-
    metheus Pharmacy, supra, 
    294 Conn. 594
    . It first
    explained that ‘‘the facts on which an expert relies
    for his medical opinion is relevant to determining the
    admissibility of the expert opinion, but once determined
    to be admissible, there is no rule establishing what
    precise facts must be included to support an expert
    opinion.’’ 
    Id.
     It then stated that ‘‘[o]nce [the expert’s]
    report was admitted into evidence, the trier of fact—
    the commissioner—was free to determine the weight
    to be afforded to that evidence.’’ 
    Id.
     The court noted
    that ‘‘[i]f the defendants sought to challenge the credibil-
    ity or weight to be afforded to [the attending physi-
    cian’s] expert opinion of causation they could have
    done so by deposing him prior to the hearing or calling
    him as a witness at the hearing.’’ 
    Id.
     The defendants
    had done neither. Accordingly, the court determined
    that the commissioner’s reliance on the attending physi-
    cian’s expert opinion was reasonable. 
    Id.
    We conclude in the present case that the commis-
    sioner had before him competent medical evidence
    from which he could find a causal relationship between
    the plaintiff’s work activities and his need for surgery.14
    Specifically, the commissioner had before him the
    records of the plaintiff’s treating physician, Paret, in
    which he reported the plaintiff’s condition, symptoms,
    and course of treatment. See Keenan v. Union Camp
    Corp., 
    49 Conn. App. 280
    , 285, 
    714 A.2d 60
     (1998) (letters
    and reports from treating physician that detailed plain-
    tiff’s medical condition, symptoms, and course of treat-
    ment was competent evidence to support commission-
    er’s finding that fall down stairs at plaintiff’s residence
    was caused by leg weakness resulting from workplace
    injury). Contained in those records was Paret’s expert
    opinion that the plaintiff’s knee injury was causally
    related to his work. The defendant did not object to
    the admission of Paret’s records into evidence, nor did
    it depose Paret prior to the hearing or call him as a
    witness at the hearing. As in Marandino, once Paret’s
    reports were admitted into evidence, ‘‘the trier of fact—
    the commissioner—was free to determine the weight
    to be afforded to that evidence.’’ Marandino v. Pro-
    metheus Pharmacy, supra, 
    294 Conn. 594
    . Although the
    defendant sought to challenge Paret’s opinion with the
    deposition transcript of Lena, the commissioner found
    Paret’s opinion more persuasive. Accordingly, we can-
    not conclude that the commissioner’s reliance on Par-
    et’s expert opinion was unreasonable.
    Moreover, the defendant’s contention that the plain-
    tiff only retrieved the heaviest of the fixtures—the 1400
    pound fixture—on 20 to 30 occasions over the course
    of his career does not necessitate a determination that
    Paret’s opinion was incompetent. First, although the
    board recognized that Paret’s opinion regarding causa-
    tion ‘‘does appear to be primarily based on his under-
    standing that the claimant was responsible for pushing
    and pulling heavy fixtures,’’ we do not construe Paret’s
    opinion as limited to the pushing and pulling of the
    1400 pound fixture. It is significant that Paret, in the
    same communication referencing the ‘‘heavy pulling
    and pushing of pallets of engine and turbine parts
    weighing 800 to 1400 pounds,’’ also described the plain-
    tiff’s duties as pushing and pulling parts weighing up
    to 1400 pounds. Paret opined that heavy pushing and
    pulling contributed to the plaintiff’s left knee degenera-
    tive arthritis. This opinion is consistent with Paret’s
    initial assessment that the effusions in the plaintiff’s
    knees were work-related and caused by the plaintiff
    pushing large heavy carts and racks of gears on the floor
    during back-to-back twelve hour shifts, as reported to
    Paret by the plaintiff. We conclude therefore, in line
    with Marandino, that Paret’s opinion was not incompe-
    tent for lack of supporting facts.
    In addition to the competent medical evidence sup-
    porting the commissioner’s finding of causation, we
    also look to the other evidence in the record. Our
    Supreme Court in Marandino explained that ‘‘it is
    proper to consider medical evidence along with all
    other evidence to determine whether an injury is related
    to the employment.’’ (Emphasis in original.) Marandino
    v. Prometheus Pharmacy, supra, 
    294 Conn. 595
    . The
    court determined that the plaintiff’s testimony regard-
    ing the circumstances of her injury ‘‘corroborated [the
    expert’s] medical opinion.’’ 
    Id.
     Considering the expert
    opinion ‘‘along with the other evidence,’’ the court con-
    cluded that the commissioner properly determined that
    the plaintiff’s knee injury was causally related to her
    employment. 
    Id.
    In the present case, the plaintiff testified extensively,
    both at his deposition and at the hearing, as to his
    workplace activities, and the commissioner referenced
    such testimony in his findings. Specifically, the commis-
    sioner referred to the plaintiff’s testimony regarding the
    retrieval of the 1400 pound fixture on 20 to 30 occasions,
    his retrieval of other heavy fixtures stored directly
    across the aisle from the grinder, a task that the plaintiff
    might perform 2 or 3 times per day, and the pushing
    of carts with heavy parts on a regular basis. This testi-
    mony, found credible by the commissioner, corrobo-
    rated Paret’s opinion with respect to the extensive push-
    ing and pulling of heavy parts as part of the plaintiff’s
    workplace activities.15 See Glenn v. Stop & Shop, Inc.,
    
    168 Conn. 413
    , 419, 
    362 A.2d 512
     (1975) (commissioner’s
    finding that repetitive heavy lifting required by employ-
    ment was causally connected with degenerative disc in
    plaintiff’s lower lumbar spine was not so unreasonable
    as to justify judicial interference, where treating physi-
    cian testified that there was causal connection between
    heavy lifting and plaintiff’s condition and plaintiff testi-
    fied as to nature of his work, his increasing pain, and
    his ultimate disability).
    Accordingly, we conclude that the commissioner had
    before him competent medical evidence in the form of
    Paret’s records.16
    C
    We next turn to the defendant’s contention that the
    commissioner improperly referenced work activities as
    ‘‘substantially and permanently aggravating [the plain-
    tiff’s] underlying and preexisting left knee condition’’
    that were not commented on by Paret. We preface our
    discussion by reiterating that we already have con-
    cluded that the commissioner’s ultimate determina-
    tion—that the plaintiff’s need for surgery was caused
    by his work—is supported by competent medical evi-
    dence. In light of that determination, we conclude that
    the commissioner’s reference to the plaintiff’s work
    activities beyond those expressly identified by Paret in
    his records, was not improper.
    In its findings, the commissioner stated that the fol-
    lowing repetitive work activities substantially and per-
    manently aggravated the plaintiff’s left knee injury:
    ‘‘[C]limbing up and down stairs while carrying heavy
    parts and fixtures, setting up a grinder while reaching
    and leaning on one foot, extensive pushing, pulling,
    reaching and lifting of heavy parts.’’ The defendant
    argues that although the ‘‘plaintiff’s testimony supports
    all but the last of those activities, it is emphasized that
    none of the actions were commented on by the plain-
    tiff’s treating physician . . . Paret.’’
    Although the climbing, reaching, leaning, and lifting
    activities were not expressly identified by Paret as hav-
    ing aggravated the plaintiff’s left knee injury, Paret’s
    records provide the commissioner with the basis to find
    a causal connection between the plaintiff’s work and
    his need for surgery. As our Supreme Court stated in
    Marandino, ‘‘there is no rule establishing what precise
    facts must be included to support an expert opinion.’’
    Marandino v. Prometheus Pharmacy, supra, 
    294 Conn. 594
    . Paret was not required to exhaustively chronicle
    every workplace activity of the plaintiff that formed the
    factual basis for his opinion that the plaintiff’s work
    was a substantial contributing factor to his need for
    surgery. Correspondingly, the commissioner, having
    before him expert medical evidence that the plaintiff’s
    work caused his need for surgery, was not limited in
    his consideration to only those activities expressly iden-
    tified by Paret but instead was entitled to consider the
    plaintiff’s testimony, as set forth at length previously
    in this opinion. See id., 595 (‘‘it is proper to consider
    medical evidence along with all other evidence to deter-
    mine whether an injury is related to the employment’’
    (emphasis in original)). Moreover, the fact that the com-
    missioner considered the plaintiff’s testimony regarding
    his work activities in no way undermines the adequacy
    or competency of Paret’s opinion.
    Accordingly, we reject the defendant’s argument that
    the board’s affirmance of the commissioner’s findings
    should be reversed.
    II
    The defendant’s final claim on appeal is that the com-
    missioner erred in failing to grant the defendant’s
    motion for articulation.17 Specifically, the defendant
    argues that articulation was needed to remedy ‘‘the lack
    of analysis or explanation as to how the trier was able
    to conclude that there was a substantial permanent
    aggravation of an underlying preexisting left knee con-
    dition . . . .’’ The plaintiff responds that the defen-
    dant’s motion for articulation ‘‘was an attempt to char-
    acterize one of . . . Paret’s reports in a way that [it]
    hoped would support [its] arguments on appeal. The
    commissioner obviously did not accept the [defen-
    dant’s] characterization of that report, and was acting
    within his discretionary powers in denying the motion
    for articulation.’’ We conclude that the commissioner
    did not abuse his discretion in denying the request for
    articulation.
    The following additional procedural history is rele-
    vant. Following the issuance of the commissioner’s
    decision, the defendant filed a motion to correct and
    request for articulation. In its motion, the defendant
    sought fourteen corrections to the commissioner’s find-
    ings, conclusions, and orders, and it requested an articu-
    lation. In its request for articulation, the defendant cited
    the commissioner’s finding regarding Paret’s February
    8, 2012 office note, which referenced the plaintiff’s
    three, twelve hour shifts pushing heavy carts and
    resulting swelling of his knees. The note further stated
    that ‘‘the effusion is rather significant. I believe it was
    caused by his work-related efforts pushing very heavy
    racks of gears working [twelve] hours a day for several
    days in a row. He has moderately severe degenerative
    joint disease which has been aggravated now by his
    work-related injury.’’ The defendant requested that the
    commissioner ‘‘articulate or otherwise confirm that [his
    finding referencing Paret’s February 8, 2012 note]
    merely illustrates that (1) the work-related activities
    related to pushing racks of gears caused only effusion
    or swelling in the left knee and (2) that the statement
    by . . . Paret suggests the effusion (‘it’) has aggravated
    moderately severe degenerative joint disease without
    any comment on the extent of [the] aggravation whether
    temporary or otherwise.’’ The defendant argued that
    ‘‘[t]his request is necessary to clarify the commission-
    er’s conclusion and to identify the work injury cited by
    the trier.’’ The defendant maintained that Paret dis-
    cussed ‘‘swelling in the knee and does not identify the
    nature or extent of the aggravation caused by such
    swelling . . . .’’
    On appeal to the board, the defendant argued that
    the commissioner improperly denied its motion to cor-
    rect and request for articulation. With respect to the
    request for articulation, the board determined that ‘‘[i]t
    is clear that the finding in question merely reflects Par-
    et’s statements regarding causation as recited in his
    February 8, 2012 office note, which note is consistent
    with Paret’s opinion on causation as expressed in his
    other office notes and correspondence.’’
    ‘‘[A]n articulation is appropriate where the trial
    court’s decision contains some ambiguity or deficiency
    reasonably susceptible of clarification. . . . [P]roper
    utilization of the motion for articulation serves to dispel
    any . . . ambiguity by clarifying the factual and legal
    basis upon which the trial court rendered its decision,
    thereby sharpening the issues on appeal. . . . In work-
    ers’ compensation cases, motions [for articulation] are
    granted when the basis of the commissioner’s conclu-
    sion is unclear.’’ (Citations omitted; internal quotation
    marks omitted.) Cable v. Bic Corp., 
    270 Conn. 433
    , 444–
    45, 
    854 A.2d 1057
     (2004).
    In the present case, the commissioner expressly cred-
    ited and relied on Paret’s opinions, particularly with
    regard to the impact of the plaintiff’s work activities
    on his ultimate need for a left knee replacement. We
    agree with the board that the finding with respect to
    which the defendant sought an articulation, when con-
    sidered together with Paret’s office notes and communi-
    cations, reflected Paret’s opinion that the plaintiff’s
    work activities aggravated his degenerative joint dis-
    ease. Accordingly, we conclude that the commissioner
    did not abuse his discretion in denying the defendant’s
    request for articulation and that the board did not
    improperly affirm that decision.
    The decision of the Compensation Review Board is
    affirmed.
    In this opinion the other judges concurred.
    1
    AIG Claims, Inc., the workers’ compensation insurer for Sikorsky Aircraft
    Corporation, is also a defendant in this case. For convenience, we refer in
    this opinion to Sikorsky Aircraft Corporation as the defendant.
    S. Marino’s Honda City, the plaintiff’s former employer, and its insurer,
    ACE USA-Chubb, were also parties in the proceedings before the workers’
    compensation commissioner. They are not participating in this appeal.
    2
    The defendant also claims that the board erred in relying on Garofola
    v. Yale & Towne Mfg. Co., 
    131 Conn. 572
    , 574, 
    41 A.2d 451
     (1945), to conclude
    that expert medical evidence was not necessary to determine the role of
    the plaintiff’s workplace activities in substantially and permanently aggravat-
    ing his preexisting degenerative arthritis in his left knee, resulting in the
    need for a total left knee replacement. Because we conclude that the commis-
    sioner’s finding of causation is supported by expert medical evidence in the
    record, we need not address the propriety of the board’s reliance on Garo-
    fola.
    The defendant raises an additional claim on appeal that the manner in
    which the board reached its conclusion is inconsistent with the board’s
    decisions in prior cases. Specifically, he claims that the board misapplied
    case law with respect to the ‘‘concept of considering medical evidence
    along with other evidence to determine whether an injury is related to the
    employment.’’ Because this issue is addressed in part I of this opinion, we
    need not separately address this claim. See footnote 16 of this opinion.
    3
    The plaintiff thought that he saw Richard Campbell-Jacobs, a physician,
    when he first injured his knee, but he did not receive any treatment until
    his surgery. The plaintiff did not pay for medical treatment for his left knee
    in 1972, nor did he lose time from work before the 1973 surgery. He does
    not remember whether he was paid for his time out of work after his surgery
    in 1973. The plaintiff asked for a scar award hearing, and it was held on
    August 15, 1978. The commissioner made an award of six weeks, but the
    plaintiff does not remember if he was paid. He does not recall receiving a
    disability rating from Campbell-Jacobs or being paid for any such rating.
    4
    The deposition transcript of Marino, who employed the plaintiff as a
    mechanic in his motorcycle shop, was entered into evidence at the hearing.
    Marino testified that he did not recall the plaintiff having had a left knee
    injury and that he did not receive or pay any bills on behalf of the plaintiff.
    He testified that if anyone had been injured on the job, he would have
    remembered it.
    5
    The plaintiff injured his right knee while working for the defendant in
    1985. In its principal appellate brief, the defendant notes that it ‘‘acknowl-
    edged compensability of replacement on the right knee because of that
    incident which was clearly a significant factor in subsequent degeneration.’’
    The right knee injury is not at issue in the present appeal.
    6
    The commissioner further found: ‘‘Given the time that has passed since
    the [plaintiff’s] alleged left knee injury at [Honda] on June 28, 1972, along
    with the lack of documentary evidence supporting the claim, the testimony
    of the [plaintiff] and . . . Marino were not at all persuasive. . . . The [plain-
    tiff] failed to prove that he made a timely claim for the alleged June 28,
    1972 injury, and also failed to prove that the commission would have jurisdic-
    tion over the claim under any of the exceptions set forth in [General Statutes
    §] 31-294c (c).’’
    7
    The commissioner stated that, ‘‘[a]lthough the [plaintiff] asks in his
    proposed findings that the payment of indemnity benefits be ordered, this
    issue was not noticed for the formal hearing. Future hearings may be held
    to address this issue if the parties are unable to reach a resolution.’’
    8
    When asked whether the plaintiff told Lena what course of treatment
    he wanted to pursue, Lena replied: ‘‘I don’t recall exactly what he said. As
    you know, during an employer/respondent examination, we don’t discuss
    too much.’’
    9
    Specifically, he testified: ‘‘On the housings, on the transmission housings
    on the Blackhawk, that was the heaviest fixture. That was 1400 pounds.
    They did make a smaller one and lighter one down to probably, down to
    probably 500 pounds later on, probably 10 years ago. The fixtures for the
    main rotors for like our largest aircraft, which was the CH53’s and stuff,
    those fixtures were up to [1000] pound weights.’’
    10
    See footnote 5 of this opinion.
    11
    The defendant, in its principal brief before this court, states that ‘‘[t]here
    is no evidence in the record that the [defendant] acknowledged repetitive
    trauma with respect to the right knee notwithstanding . . . Paret’s com-
    ments to counsel. The rationale on the right total knee replacement is
    different and not relevant, and the resolution of the right knee claim should
    have no bearing on the analysis of the left knee claim.’’ We note Paret’s
    reference to the right knee only because it contextualizes his discussion of
    the pushing and pulling activities as aggravating the plaintiff’s arthritis in
    his left knee.
    12
    The parties dispute whether the plaintiff had the benefit of ‘‘mechanical
    assistance’’ in retrieving the fixtures. With respect to retrieving the fixtures
    from the fixture crib, the commissioner found that ‘‘if he couldn’t get a tow
    motor operator to get the fixture, he would need to do so with a pallet jack
    or floor jack.’’ With respect to retrieving the fixtures stored across the aisle,
    which task would be performed approximately two or three times per day,
    the commissioner found that the plaintiff used a pallet jack. The plaintiff
    further testified that he would pull parts weighing 800 to 900 pounds using
    a hand truck.
    In his deposition, the plaintiff was asked what a hand truck is, and he
    responded, ‘‘A hand truck is like a pallet jack.’’ He testified that it ‘‘lifts the
    pallet’’ and then ‘‘you pull it.’’ He confirmed that he would move it with his
    own power. The defendant mentions in its brief that Paret’s opinion was
    premised on the plaintiff pushing and pulling heavy fixtures ‘‘without
    mechanical assistance,’’ however, we note that Paret’s full statement pro-
    vides that the plaintiff was ‘‘responsible . . . for pulling very heavy loads
    weighing up to 1400 pounds on pull carts with no mechanical assistance
    . . . .’’ (Emphasis added.) We see no conflict among Paret’s opinion, the
    plaintiff’s testimony, and the commissioner’s findings with respect to the
    assistance available to the plaintiff to move the fixtures and parts.
    13
    The record in Marandino also contained a November, 2000 note
    authored by the plaintiff’s treating physician that stated: ‘‘I feel that there
    is [a] direct related cause of the knee injury to the right elbow pre-existing
    problem.’’ (Emphasis omitted; internal quotation marks omitted.) Maran-
    dino v. Prometheus Pharmacy, supra, 
    294 Conn. 588
    . This court and our
    Supreme Court declined to address the defendant’s claim on appeal that
    the November, 2000 note improperly was admitted into evidence, on the
    basis that it was cumulative of the April, 2002 letter, to which the defendants
    had not objected. 
    Id.,
     588 n.13.
    14
    The defendant relies on Avino v. Stop & Shop Supermarket Cos. LLC/
    Ahold USA, No. 5820, CRB 3-13-2 (February 10, 2014) as setting forth the
    type of medical evidence required to establish work-related aggravation of
    preexisting arthritis such as the plaintiff had in the present case. In that
    case, the commissioner found that the plaintiff’s preexisting osteoarthritis
    was ‘‘ ‘accelerated by the employment activity’ ’’ and, therefore, that his
    injury was compensable. The plaintiff had undergone medial and lateral
    open meniscectomies when he was a teenager, and his treating physician
    testified that these procedures typically lead to osteoarthritis. The plaintiff
    began treating forty years following the surgeries for bilateral knee pain, at
    which time his physician diagnosed him as suffering from bilateral end-
    stage degenerative joint disease of the knees. The physician testified that
    the heavy work performed by the plaintiff as a meat cutter had exacerbated
    his knee symptoms. He described the arthritic changes in the plaintiff’s
    knees as ‘‘ ‘probably multifactorial,’ ’’ and opined that the plaintiff probably
    would have developed significant arthritis in his knees ‘‘ ‘whether or not he
    worked as a meat cutter.’ ’’ However, he further opined that the work activi-
    ties of the plaintiff, particularly heavy lifting and deep squatting, likely had
    ‘‘ ‘aggravated his underlying condition and required him to have replacement
    earlier than he potentially would have had he had a more sedentary job.’ ’’
    Another physician performed a medical examination at the request of the
    defendant and determined that the plaintiff’s duties as a meat cutter had
    aggravated his osteoarthritis but were not a substantial contributing factor
    in its development.
    The board found that the record provided ‘‘ample support’’ for the commis-
    sioner’s conclusion that the plaintiff’s job duties were a significant contribut-
    ing factor to his need for knee replacement surgery.
    We agree with the defendant that the medical evidence presented in Avino
    is stronger than that presented before the commissioner in the present case.
    We disagree, however, that the medical evidence in the present case was
    so lacking that it could not support the commissioner’s finding of causation.
    15
    In its reply brief, the defendant contends that ‘‘[w]hile . . . Paret was
    of the opinion moving up to the 1400 pound parts aggravated the plaintiff’s
    left knee condition, this is at best an undefined aggravation.’’ It maintains
    that there is no comment from Paret that the plaintiff’s work activities
    ‘‘permanently aggravated his left knee condition.’’ The defendant states that
    ‘‘a left knee effusion was present’’ in February, 2012, but that the effusion
    had resolved by the time of surgery in February, 2015. We note, however,
    that Paret’s records indicate that he had recommended surgery as early as
    February, 2012, and that, by March 14, 2012, the plaintiff was considering
    surgical options of a total knee replacement because Paret thought that
    ‘‘there is very little else that we can offer other than the very conservative
    management treatment course which has been ineffective so far.’’
    16
    We note here the defendant’s claim on appeal that the board’s decision
    ‘‘represents a departure from the procedure which guides all counsel within
    the [workers’ compensation] system on a daily basis.’’ See footnote 2 of
    this opinion. In support of this claim, the defendant argues that the board
    has ‘‘misapplied the reference in Murchison [v. Skinner Precision Indus-
    tries, Inc., supra, 
    162 Conn. 152
    ] with respect to the concept of considering
    medical evidence along with other evidence to determine whether an injury
    is related to the employment. . . . The court did not suggest that an opinion
    expressed with reasonable medical probability as to whether the work
    activity was a substantial contributing cause was no longer necessary.
    Rather, competent and probative medical testimony is necessary which is
    then viewed through the lens that considers the other evidence produced
    in the case.’’ (Citation omitted.) Because we conclude that the commissioner
    had before him competent medical evidence, we need not address the defen-
    dant’s argument that it is improper to supplement incompetent medical
    evidence with other evidence.
    17
    The defendant does not claim on appeal that the commissioner abused
    his discretion in denying its motion to correct.