Court Opinion

ID: 9953108
Source: CourtListenerOpinion
Date Created: 2024-03-21 15:22:40.417513+00
Date Added: 2024-06-11T14:45:40.769397
License: Public Domain

IN THE SUPREME COURT, STATE OF WYOMING

                                        2024 WY 29

                                                       OCTOBER TERM, A.D. 2023

                                                                   March 21, 2024

 JUDY VALENCIA,

 Appellant
 (Petitioner),

 v.
                                                      S-23-0174
 STATE OF WYOMING, ex rel.
 DEPARTMENT OF WORKFORCE
 SERVICES, WORKERS’
 COMPENSATION DIVISION,

 Appellee
 (Respondent).

                    Appeal from the District Court of Campbell County
                       The Honorable James Michael Causey, Judge

Representing Appellant:
      Donna D. Domonkos, Domonkos & Thorpe, LLC, Cheyenne, Wyoming.

Representing Appellee:
      Bridget Hill, Wyoming Attorney General; Mark Klaassen, Deputy Attorney
      General; Peter Howard, Senior Assistant Attorney General; Holli J. Welch, Senior
      Assistant Attorney General.

Before FOX, C.J., and KAUTZ, BOOMGAARDEN, GRAY, and FENN, JJ.

NOTICE: This opinion is subject to formal revision before publication in Pacific Reporter Third.
Readers are requested to notify the Clerk of the Supreme Court, Supreme Court Building, Cheyenne,
Wyoming 82002, of typographical or other formal errors so correction may be made before final
publication in the permanent volume.
KAUTZ, Justice.

[¶1] Judy Valencia suffered an injury to her right knee which was covered by workers’
compensation. She later sought workers’ compensation benefits for injuries to her left foot,
ankle, and hammertoe, claiming they were causally related to her compensable right knee
injury. The Wyoming Department of Workforce Services, Workers’ Compensation
Division (Division) disagreed and denied benefits. The Wyoming Medical Commission
upheld the denial, concluding Ms. Valencia had failed to satisfy her burden of showing her
compensable right knee injury caused her left foot, ankle, and hammertoe injuries. The
district court affirmed the Commission’s decision. We also affirm.

                                          ISSUES

[¶2] Ms. Valencia raises two issues which we re-state as one: Was the Medical
Commission’s decision that Ms. Valencia had not met her burden of showing her left foot,
ankle, and hammertoe injuries were caused by her compensable right knee injury supported
by substantial evidence?

                                           FACTS

[¶3] On August 21, 2020, Ms. Valencia was working as an administrative assistant at
R&G Electric, Inc., in Gillette, Wyoming, when she went outside to take pictures of hail
damage to the building for R&G Electric’s insurer. She stepped in an indentation in the
grass and hyperextended her right knee. Dr. Mark Murphy diagnosed her with a right knee
meniscus tear, which he surgically repaired on September 24, 2020. Four days after
surgery, Ms. Valencia began physical therapy twice per week with Brandy Johnson, PT,
DPT. On that date, Dr. Johnson noted, among other things, that Ms. Valencia had an
“impaired gait.” On December 17, 2020, Dr. Johnson documented that Ms. Valencia’s gait
had “normalized.” Ms. Valencia concluded physical therapy for her right knee on
December 30, 2020. Ms. Valencia applied for and received workers’ compensation
benefits for her right knee injury.

[¶4] On March 31, 2021, Ms. Valencia returned to Dr. Murphy complaining of right knee
pain. Dr. Murphy noted Ms. Valencia “was doing [physical therapy] until the end of
December and started walking[,] was doing okay walking 3 to 4 miles but went bowling .
. . about a week ago and subsequently could not walk[,] . . . has difficulty with stairs[, and]
the pain wakes her up at night and is around her patella on the right knee and her anterior
knee.” Dr. Murphy treated her right knee with an anti-inflammatory injection.

[¶5] In the meantime, on March 9, 2021, Ms. Valencia visited Dr. Robert Grunfeld for
left foot pain. According to Dr. Grunfeld’s notes:

                                              1
              Patient is here for left foot pain. This has been going on for
              several years but she has noticed worsening . . . pronation . . .
              the last few months. Last summer she twisted her ankle and
              now has pain with walking longer distances. Her ankle feels
              unstable. She states that “bone in the middle arch has moved”.
              ...

Dr. Grunfeld diagnosed her with left calcaneal vaigus alignment, left equinus contracture,
left posterior tibial tendinitis, and left fourth hammertoe. On April 14, 2021, he performed
reconstructive surgery on Ms. Valencia’s left foot, ankle, and hammertoe. In his post-
operative notes, with respect to his correction of her left hammertoe, he stated: “Her toe
was previously corrected, but it fused in an uncomfortable position[.]” Ms. Valencia again
began physical therapy with Dr. Johnson.

[¶6] On June 8, 2021, Ms. Valencia had a post-operative visit with Dr. Grunfeld. He
noted:

              [Ms. Valencia] had some concerns with regards to her
              Worker’s Compensation claim. In August 2020, specifically
              August 21, 2020[,] she had an injury while she was walking at
              work into a divot and her right knee gave out. She had a right
              knee surgery on 9/24/2020 with Dr. Murphy. Due to the
              alteration in her gait her favoring her operative side she ended
              up developing severe left foot pain. Patient states that she
              noticed that she was “walking funny” after the knee surgery.
              This does appear to be related to the patient’s original Worker’s
              Comp. claim with regards to the right knee surgery that she
              needed on 9/24/2020. She developed . . . progressive . . . left
              foot pain and deformity along with posterior tibial tendinitis.
              Surgery was successfully completed on April 14, 2021[,] of
              this year and she has been doing well. Patient states that she
              had no previous injury to the left foot but does have a history
              of a remote left ankle injury, which is not related to the problem
              that I’m currently treating her for.

              Hammertoe correction with [proximal interphalangeal] joint
              resection and pinning was completed at time of surgery due to
              progressive deformity from an antalgic gait, related to the knee
              surgery that the patient underwent on the contralateral lower
              extremity.

[¶7] Ms. Valencia submitted the bills for the treatment she received on her left foot,
ankle, and hammertoe to the Division, claiming her altered gait following her August 2020

                                              2
right knee injury caused her left foot, ankle, and hammertoe injuries. The Division denied
payment because Ms. Valencia’s left foot, ankle, and hammertoe injuries were not related
to her right knee injury. Ms. Valencia objected to the Division’s determination and
requested a hearing. The Division transferred the matter to the Medical Commission for a
contested case hearing.

[¶8] Prior to the hearing, the Division referred Ms. Valencia to Dr. Ricardo Nieves for
an independent medical evaluation (IME), which was completed on September 17, 2021.
After examining Ms. Valencia and reviewing her medical records, he opined: “In my
professional opinion within a reasonable degree of medical probability there is no causal
relationship between the 8/21/2020 work injury and the left ankle-foot surgeries performed
by Dr. Grunfeld on 4/14/2021.” He determined Dr. Grunfeld’s assessment that Ms.
Valencia developed severe left foot pain and progressive deformity from her antalgic gait
following her right knee surgery was “unfounded,” “not supported by evidence-based
medicine,” and was contradicted by Dr. Grunfeld’s March 9, 2021, report wherein he stated
Ms. Valencia’s left foot pain had been ongoing for several years, the pain had worsened in
the last few months, and she had problems walking after twisting her ankle the previous
summer. Dr. Nieves also noted Dr. Murphy’s records showed that upon completing
physical therapy for her right knee injury, Ms. Valencia was “walking 3 to 4 miles with no
evidence on the medical records of problems with the left foot.” Dr. Nieves recognized
Ms. Valencia had a significant past medical history of foot problems, including
bunionectomies on her right and left feet in 1985 and 1986, respectively; a corn removal
on her left fifth toe in 1992; hammertoe correction on the right and left fourth toes in 1992;
surgery to release plantar fascia on both the right and left sides in 2009; and a left ankle
sprain in the summer of 2019. He opined that “within a reasonable degree of medical
probability the 8/21/2020 workplace incident did not cause any temporary exacerbations
of pre-existing conditions of the left foot and ankle” or “any permanent material
aggravation of pre-existing conditions of the left foot and ankle.” Dr. Nieves further stated
the medical literature does not support a causal relationship between an injury to a lower
limb based upon an individual favoring the opposite lower extremity.

[¶9] On September 30, 2021, Dr. Johnson authored a written opinion regarding the cause
of Ms. Valencia’s left foot, ankle, and hammertoe injuries. She stated that when Ms.
Valencia began physical therapy on September 28, 2020, she was “limping significantly .
. . to the point she was also complaining of back pain.” According to Dr. Johnson, Ms.
Valencia continued to limp for the next couple of months as she worked on getting her
right knee to move correctly and to tolerate full weight while walking. “In that process,
[Ms. Valencia] began to have left foot pain and . . . splaying of her left toes.” Dr. Johnson
stated Ms. Valencia continued to have left foot pain even after her gait normalized and
even after she had no further issues with her right knee. She noted

              Altered gait pattern over several months can frequently cause
              foot pain and changes in the feet as clearly stated in a PubMed

                                              3
              article as follows: “In a normal, healthy person, gait is cyclical
              and symmetric process. However, when an abnormality is
              present in one of the joints, muscles, or bones of the complex
              system that regulates gait, this process is disrupted.” “Very
              small variations in these things are usually nothing to worry
              about. However, if your foot shape or gait mechanics deviate
              too far from a ‘normal,’ neutral stride, you can start to become
              more susceptible to things like heel pain, shin splints, stress
              fractures, bunions, and other deformities or sports injuries.” . .
              . Waco Foot and Ankle[,] January 2020.

Dr. Johnson opined Ms. Valencia’s “[l]eft foot pain and damage very well could be the
result of her altered gait pattern following her injury in August of 2020.”

[¶10] After holding a contested case hearing on August 3, 2022, the Medical Commission
affirmed the Division’s denial of benefits. It concluded Ms. Valencia had failed to prove
she suffered a second compensable injury to her left foot, ankle, and hammertoe as a result
of her August 2020 workplace accident or that her August 2020 right knee injury caused a
material aggravation of her preexisting left foot conditions resulting in the need for medical
care and surgery. In so concluding, it discounted the causation opinions of Dr. Johnson
and Dr. Grunfeld and instead agreed with Dr. Nieves’ opinion that there was no causal
relationship between Ms. Valencia’s right knee injury and her left foot, ankle, and
hammertoe injuries. Ms. Valencia petitioned the district court for review of the Medical
Commission’s decision. The district court affirmed the decision, and Ms. Valencia timely
appealed to this Court.

                               STANDARD OF REVIEW

[¶11] “When an appeal is taken from a district court’s review of an administrative
agency’s decision, we examine the case as if it came directly from the agency, giving no
special deference to the district court’s decision.” McCallister v. State ex rel. Dep’t of
Workforce Servs., Workers’ Comp. Div., 2022 WY 66, ¶ 7, 510 P.3d 1051, 1054 (Wyo.
2022) (citing In re Vinson, 2020 WY 126, ¶ 25, 473 P.3d 299, 308 (Wyo. 2020), and
Guerrero v. State ex rel. Dep’t of Workforce Servs., Workers’ Comp. Div., 2015 WY 88, ¶
11, 352 P.3d 262, 265 (Wyo. 2015)) (other citation omitted). Our review is governed by
Wyo. Stat. Ann. § 16-3-114(c) (LexisNexis 2023), which states in relevant part:

              (c) To the extent necessary to make a decision and when
              presented, the reviewing court shall decide all relevant
              questions of law, interpret constitutional and statutory
              provisions, and determine the meaning or applicability of the
              terms of an agency action. In making the following
              determinations, the court shall review the whole record or

                                              4
             those parts of it cited by a party and due account shall be taken
             of the rule of prejudicial error. The reviewing court shall:
                     ...
                 (ii) Hold unlawful and set aside agency action, findings and
             conclusions found to be:
                     (A) Arbitrary, capricious, an abuse of discretion or
             otherwise not in accordance with law; [or]
                     ...
                     (E) Unsupported by substantial evidence in a case
             reviewed on the record of an agency hearing provided by
             statute.

Vinson, ¶ 25, 473 P.3d at 308 (citation and internal quotation marks omitted).

[¶12] Pursuant to § 16-3-114(c)(ii)(E), “we review the agency’s findings of fact by
applying the substantial evidence standard.” McCallister, ¶ 8, 510 P.3d at 1054 (citing
Vinson, ¶ 26, 473 P.3d at 308). “Findings of fact are supported by substantial evidence if
there is relevant evidence in the record which ‘a reasonable mind might accept in support
of the agency’s conclusion.’” Id. (quoting Dale v. S & S Builders, LLC, 2008 WY 84, ¶
11, 188 P.3d 554, 558 (Wyo. 2008)). When reviewing an agency’s decision that a claimant
did not meet her burden of proof, we apply the following standard:

             If the hearing examiner determined that the burdened party
             failed to meet [her] burden of proof, we will decide whether
             there is substantial evidence to support the agency’s decision
             to reject the evidence offered by the burdened party by
             considering whether that conclusion was contrary to the
             overwhelming weight of the evidence in the record as a whole.
             See, Wyo. Consumer Group v. Public Serv. Comm’n of Wyo.,
             882 P.2d 858, 860-61 (Wyo. 1994); Board of Trustees,
             Laramie County School Dist. No. 1 v. Spiegel, 549 P.2d 1161,
             1178 (Wyo. 1976) (discussing the definition of substantial
             evidence as “contrary to the overwhelming weight of the
             evidence”). If, in the course of its decision making process, the
             agency disregards certain evidence and explains its reasons for
             doing so based upon determinations of credibility or other
             factors contained in the record, its decision will be sustainable
             under the substantial evidence test. Importantly, our review of
             any particular decision turns not on whether we agree with the
             outcome, but on whether the agency could reasonably conclude
             as it did, based on all the evidence before it.

                                            5
Hardy v. State ex rel. Dep’t of Workforce Servs., Workers’ Comp. Div., 2017 WY 42, ¶ 10,
394 P.3d 454, 457 (Wyo. 2017) (quoting Hood v. State ex rel. Dep’t of Workforce Servs.,
Workers’ Comp. Div., 2016 WY 104, ¶ 14, 382 P.3d 772, 776 (Wyo. 2016), and Dale, ¶
22, 188 P.3d at 561).

[¶13] “‘Even if an agency record contains sufficient evidence to support the administrative
decision under the substantial evidence test, this Court applies the arbitrary-and-capricious
standard as a “safety net” to catch other agency action that may have violated the Wyoming
Administrative Procedures Act.’” Vinson, ¶ 27, 473 P.3d at 309 (quoting Rodgers v. State
ex rel. Wyo. Workers’ Safety & Comp. Div., 2006 WY 65, ¶ 19, 135 P.3d 568, 575 (Wyo.
2006), and citing Dale, ¶ 23, 188 P.3d at 561). For example, “the arbitrary and capricious
standard will apply if the hearing examiner refused to admit testimony or documentary
exhibits that were clearly admissible or failed to provide appropriate findings of fact or
conclusions of law.” Dale, ¶ 23, 188 P.3d at 561.

[¶14] “We review an agency’s conclusions of law de novo and affirm only if its
conclusions are in accordance with the law.” Triplett v. State ex. rel. Dep’t of Workforce
Servs., Workers’ Comp. Div., 2021 WY 118, ¶ 35, 497 P.3d 903, 911 (Wyo. 2021) (citing
§ 16-3-114(c)(ii)(A)).

                                      DISCUSSION

[¶15] Ms. Valencia maintains the Medical Commission improperly decided she had not
met her burden of showing her left foot, ankle, and hammertoe injuries were causally
related to her August 2020 right knee injury. She claims she presented evidence
demonstrating her right knee injury led to an altered gait, which in turn caused a second
compensable injury (her left foot, ankle, and hammertoe injuries) or, at a minimum,
materially aggravated her 20-year old preexisting left foot conditions. We address each
argument separately.

       Second Compensable Injury

[¶16] “Wyoming law has long recognized that a single incident at work can give rise to
more than one compensable injury. . . . This principle, referred to as the second
compensable injury rule, applies when ‘an initial compensable injury ripens into a
condition requiring additional medical intervention.’” In re Kaczmarek, 2009 WY 110, ¶
9, 215 P.3d 277, 281 (Wyo. 2009) (citing Baldwin v. Scullion, 62 P.2d 531, 539 (Wyo.
1936), and quoting Yenne-Tully v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 12
P.3d 170, 172 (Wyo. 2000)). “‘[A] subsequent injury or condition is compensable if it is
causally linked to the initial compensable work injury.’” Ross v. State ex rel. Dep’t of
Workforce Servs., 2022 WY 11, ¶ 13, 503 P.3d 23, 29 (Wyo. 2022) (quoting Ball v. State
ex rel. Wyo. Workers’ Safety & Comp. Div., 2010 WY 128, ¶ 24, 239 P.3d 621, 628 (Wyo.
2010), and citing Alvarez v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 2007 WY

                                             6
126, ¶ 18, 164 P.3d 548, 552 (Wyo. 2007)). “Our description of the required causal
connection between the first and second injuries has varied slightly from case to case but
in every case ‘[t]he employee must show, by a preponderance of the evidence, that it is
more probable than not that the second injury was caused by the first.’” Boylen v. State ex
rel. Dep’t of Workforce Servs., Workers’ Comp. Div., 2022 WY 39, ¶ 11, 506 P.3d 765,
769 (Wyo. 2022) (quoting Ross, ¶ 13, 503 P.3d at 29). See also, Kaczmarek, ¶ 11, 215
P.3d at 282-83 (“[I]n a second compensable injury case, the claimant must show, by a
preponderance of the evidence, that it is more probable than not that there exists a causal
connection between the first and second injuries.”).

[¶17] The Medical Commission concluded that because Ms. Valencia’s left foot, ankle,
and hammertoe injuries were not “so immediately and directly or naturally and probably”
the result of her August 2020 right knee injury, expert medical testimony was necessary to
establish the requisite link between the two. Morris v. State ex rel. Dep’t of Workforce
Servs., Workers’ Comp. Div., 2017 WY 119, ¶ 47, 403 P.3d 980, 993 (Wyo. 2017)
(“Medical evidence is typically required to [establish the causal connection between the
first workplace injury and the second injury] unless the [second injury] is immediately and
directly or naturally and probably the result of the workplace [injury].” (citation and
internal quotation marks omitted)). See also, Matter of Lysne, 2018 WY 107, ¶¶ 18-19,
426 P.3d 290, 296 (Wyo. 2018) (“We have required medical evidence to establish
causation when a significant amount of time elapses between the initial workplace injury
and the claim, when there is an intervening injury, when there is a preexisting condition,
or when the claimant’s symptoms and medical history are complex . . . . However, when
the medical condition is immediately and directly or naturally and probably the result of
the workplace incident, we have not required medical testimony.” (citations and internal
quotation marks omitted)). Ms. Valencia does not disagree with this conclusion on appeal.
She argues, however, that she presented the necessary medical evidence as both Dr.
Johnson and Dr. Grunfeld opined that her left foot, ankle, and hammertoe injuries were
caused by her altered gait following her right knee injury. According to her, the Medical
Commission improperly disregarded these opinions.

[¶18] “The fact-finder in a contested case hearing, in this case [the Medical Commission],
must evaluate the medical records and testimony, including medical expert testimony, and
determine the weight of the available evidence.” Delacastro v. State ex rel. Wyo. Workers’
Safety & Comp. Div., 2014 WY 40, ¶ 23, 321 P.3d 327, 333 (Wyo. 2014) (citing Kenyon
v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 2011 WY 14, ¶ 24, 247 P.3d 845, 852
(Wyo. 2011)). The Commission “‘is entitled to disregard an expert opinion if [it] finds the
opinion unreasonable, not adequately supported by the facts upon which the opinion is
based, or based upon an incomplete and inaccurate medical history provided by the
claimant.”’ Id. (quoting Watkins v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 2011
WY 49, ¶ 25, 250 P.3d 1082, 1090-91 (Wyo. 2011), and Taylor v. State ex rel. Wyo.
Workers’ Safety & Comp. Div., 2005 WY 148, ¶ 15, 123 P.3d 143, 148 (Wyo. 2005)). “‘In
weighing the medical opinion testimony, the [Commission] considers: (1) the opinion; (2)

                                            7
the reasons, if any, given for it; (3) the strength of it; and (4) the qualifications and
credibility of the witness or witnesses expressing it.’” Reichenberg v. State ex rel. Dep’t
of Workforce Servs., Workers’ Comp. Div., 2022 WY 36, ¶ 34, 506 P.3d 732, 743 (Wyo.
2022) (quoting Anastos v. Gen. Chem. Soda Ash, 2005 WY 122, ¶ 20, 120 P.3d 658, 666
(Wyo. 2005), and Bando v. Clure Bros. Furniture, 980 P.2d 323, 329-30 (Wyo. 1999)).
We will not overturn the Medical Commission’s credibility determinations or its weighing
of the evidence unless they are “clearly contrary to the great weight of the evidence.”
Hoffman v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 2012 WY 164, ¶ 23, 291 P.3d
297, 305 (Wyo. 2012).

[¶19] The Medical Commission found Dr. Johnson’s written opinion that Ms. Valencia’s
left foot, ankle, and hammertoe injuries “very well could be” the result of her altered gait
pattern following her August 2020 right knee injury did not satisfy Ms. Valencia’s burden
because “could be” is not sufficient under our precedent to satisfy a claimant’s burden of
proof on causation. It was correct. While we do not require “the claimant to prove to a
degree of medical certainty that the second injury is due solely to the first injury,” the
medical testimony must establish that the first injury “contributed to,” “most likely
caused,” or “probably caused” the second injury. Hardy, ¶ 12, 394 P.3d at 458 (citing
Kaczmarek, ¶ 11, 215 P.3d at 282-83, and State ex rel. Wyo. Worker’s Safety & Comp. Div.
v. Armijo, 2004 WY 116, ¶ 8, 99 P.3d 445, 449-50 (Wyo. 2004)). “[M]edical testimony in
terms of ‘can,’ ‘could,’ or ‘possibly’ is insufficient to meet a claimant’s burden of proof.”
Id. (quoting Boyce v. State ex rel. Wyo. Workers’ Safety & Comp. Div., 2005 WY 9, ¶ 21,
105 P.3d 451, 458 (Wyo. 2005)).

[¶20] Dr. Johnson clarified during her testimony at the contested case hearing that it was
“more probable than not” that Ms. Valencia’s left foot, ankle, and hammertoe injuries were
the result of her altered gait pattern following her right knee injury. While this testimony
would, under our precedent, be sufficient to establish the requisite causal link between the
first and second injuries, the Medical Commission nevertheless discounted it because Dr.
Johnson only offered it after being pressed by Ms. Valencia’s attorney, she “did not provide
a medical explanation as to how the left foot [injuries], which required significant surgical
intervention, could result from a contralateral knee injury and a two to three month limp,”
and her opinion was not supported by her treatment notes. Ms. Valencia claims the fact
Dr. Johnson did not place her observations about Ms. Valencia’s left foot pain in her
treatment notes is an arbitrary reason to disregard Dr. Johnson’s live testimony, which was
subject to cross-examination. In any event, Ms. Valencia maintains Dr. Johnson’s
treatment notes included her observations that Ms. Valencia had an altered gait and was
placing more weight on her left foot as a result of her right knee injury. She also alleges
the treatment notes from October 12 and 15, 2020, document Ms. Valencia’s complaints
of left foot pain.

[¶21] The Medical Commission reasonably discounted Dr. Johnson’s opinion testimony
because it was not supported by her treatment notes. Dr. Johnson testified Ms. Valencia

                                             8
complained of left foot pain while undergoing physical therapy for her right knee injury.
Dr. Johnson stated those complaints should be reflected in her treatment notes. Yet, none
of the notes indicate Ms. Valencia was having left foot pain, let alone that the left foot pain
was a result of her altered gait following her right knee surgery. Dr. Johnson’s treatment
notes from October 12 and October 15, 2020, merely reflect that Ms. Valencia “report[ed]
that her knee felt good over the weekend [but] she still continues to have left side soreness.”
There is no indication these notes refer to left foot, ankle, or toe pain as opposed to pain on
the left side of her right knee. Indeed, in the immediately preceding treatment notes, Dr.
Johnson stated Ms. Valencia reported “her knee felt pretty good after her last treatment,”
“her knee hurt all weekend and it[’s] sore today,” and “[h]er knee felt better after [the] last
treatment [but she] still has discomfort on the lateral side.” Taken in context with the
earlier notes, the October 12 and 15 notes appear to refer only to her right knee.

[¶22] The Medical Commission also reasonably rejected Dr. Grunfeld’s June 8, 2021,
assessment that Ms. Valencia’s left foot, ankle, and hammertoe injuries resulted from her
altered gait following her August 2020 right knee injury. As the Commission explained,
Dr. Grunfeld provided no explanation for how Ms. Valencia’s “substantial left foot
conditions . . . includ[ing] a total reconstruction of her left foot could occur due to a two to
three month altered gait from an injury to a contralateral body part.” He also did not state
his opinion on causation to a reasonable degree of medical probability or opine that she
suffered a second compensable injury as a result of her right knee injury. Moreover, his
opinion directly contradicted his March 9, 2021, treatment record noting Ms. Valencia’s
left foot conditions had been ongoing for several years, thereby indicating they were not
caused by the August 2020 workplace accident or the resulting right knee injury.

[¶23] Ms. Valencia argues the Medical Commission’s decision that she did not meet her
burden under the second compensable injury rule was against the overwhelming weight of
the evidence. Again, she relies on Dr. Johnson’s causation opinion and faults the Medical
Commission for not giving it greater weight than Dr. Nieves’ opinion.

[¶24] “When presented with conflicting expert medical testimony, the [Medical
Commission] determines the credibility and weight of the experts’ opinions.” Stevens v.
State ex rel. Dep’t of Workforce Servs., Workers’ Safety & Comp. Div., 2014 WY 153, ¶
36, 338 P.3d 921, 929 (Wyo. 2014). See also, Hayes v. State ex rel. Wyo. Workers’ Safety
& Comp. Div., 2013 WY 96, ¶ 16, 307 P.3d 843, 849 (Wyo. 2013) (“When conflicting
medical opinions are presented at the contested case hearing, the agency has the
responsibility, as the trier of fact, to determine relevancy, assign probative value, and
ascribe the relevant weight given to the evidence presented.” (citation and internal
quotation marks omitted)). In fact, “[d]etermining whether a claimant is entitled to benefits
where, as here, there exists conflicting medical testimony is precisely the purpose for which
the Commission was created.” Watkins, ¶ 25, 250 P.3d at 1091 (citing French v. Amax
Coal West, 960 P.2d 1023, 1030 (Wyo. 1998)). As we stated above, we will not overturn
the Medical Commission’s credibility determinations or its weighing of the evidence unless

                                               9
they are “clearly contrary to the great weight of the evidence.” Hoffman, ¶ 23, 291 P.3d at
305.

[¶25] The Medical Commission’s decision to give more weight to Dr. Nieves’ causation
opinion than to Dr. Johnson’s was not against the great weight of the evidence. Dr.
Johnson’s causation opinion changed over time and her testimony concerning Ms.
Valencia’s left foot pain was not supported by her treatment notes. In contrast, Dr. Nieves’
opinion was based on his examination of Ms. Valencia, his review of her medical records,
including her prior left foot conditions, was stated to a reasonable degree of medical
probability, and was supported by medical research.

[¶26] The Medical Commission’s decision that Ms. Valencia failed to meet her burden of
showing she suffered a second compensable injury to her left foot, ankle, and hammertoe
as a result of her August 2020 workplace accident was supported by substantial evidence.

       Material Aggravation of a Preexisting Condition

[¶27] “Preexisting conditions are generally excluded from the definition of compensable
injury.” Guerrero, ¶ 23, 352 P.3d at 269 (citing Wyo. Stat. Ann. § 27-14-102(a)(xi)(F)
(“‘Injury’ does not include . . . [a]ny injury or condition preexisting at the time of
employment with the employer against whom a claim is made.”)). “However, an employee
who has a pre-existing condition may still recover if h[er] ‘employment aggravated,
accelerated, or combined with the disease or infirmity to produce the death or disability for
which compensation is sought.’” Id. (quoting Dutcher v. State ex rel. Wyo. Workers’ Safety
& Comp. Div., 2010 WY 10, ¶ 14, 223 P.3d 559, 562 (Wyo. 2010), and citing Lindbloom
v. Teton Int’l, 684 P.2d 1388, 1389 (Wyo. 1984), and Larson’s Workmen’s Compensation
Law). “‘To prove aggravation of a preexisting condition, a claimant must demonstrate by
a preponderance of the evidence that the work contributed to a material degree to the
aggravation of the condition.’” Id. at 269-70 (quoting Middlemass v. State ex rel. Wyo.
Workers’ Safety & Comp. Div., 2011 WY 118, ¶ 15, 259 P.3d 1161, 1165 (Wyo. 2011),
and Dutcher, ¶ 15, 223 P.3d at 562). See also, Langberg v. State ex rel. Wyo. Workers’
Safety & Comp. Div., 2009 WY 39, ¶ 17, 203 P.3d 1098, 1102 (Wyo. 2009) (“It is [the
claimant’s] burden to prove, by a preponderance of the evidence, his work-related injuries
materially aggravated, accelerated, or combined with [a preexisting condition].” (citations
omitted)).

[¶28] Ms. Valencia argues the Medical Commission’s decision that she had failed to prove
her altered gait following her August 2020 right knee injury materially aggravated her 20-
year old preexisting left foot conditions is contrary to the overwhelming weight of the
evidence. She again relies on Dr. Johnson’s and Dr. Grunfeld’s causation opinions and
maintains the Commission erred in disregarding them and instead agreeing with Dr.
Nieves’ opinion.

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[¶29] The Medical Commission found Ms. Valencia’s medical records demonstrated she
suffered from preexisting left foot conditions, including removal of a bunion and a corn,
correction of a hammertoe, and release of the plantar fascia. However, while Ms. Valencia
claims these conditions were successfully treated over twenty years ago, the record reveals
she sought treatment from Dr. Daniel Allen for left foot pain and was diagnosed with sinus
tarsi/tenosynovitis of the left foot in February 2017, a mere three years before her right
knee injury. In any event, Ms. Valencia’s argument that her altered gait following her right
knee injury materially aggravated her preexisting left foot conditions is not supported by
the medical evidence.

[¶30] “Regarding proof of aggravation of a preexisting condition we have stated that
‘expert medical testimony ordinarily will be required to establish the link between the
worsening of the medical condition and the claimant’s work activities, rather than some
other factor.’” Hayes, ¶ 19, 307 P.3d at 849 (citing Boyce, ¶ 16, 105 P.3d at 456)). Neither
Dr. Johnson nor Dr. Grunfeld opined that Ms. Valencia’s altered gait following her right
knee injury materially aggravated her preexisting left foot conditions. In fact, with the
exception of knowing that Ms. Valencia had surgery on her hammertoe “years and years”
ago, Dr. Johnson was not aware of “any problems [Ms. Valencia] had with her feet.” Dr.
Grunfeld’s notes reveal he knew Ms. Valencia’s left hammertoe was previously corrected,
that she had experienced left foot pain for several years before March 2021, and that she
had a history of a remote left ankle injury. Yet, his notes also state that Ms. Valencia told
him she had no previous injury to her left foot. In contrast, Dr. Nieves was aware of her
preexisting left foot conditions and determined within a reasonable degree of medical
probability that her August 2020 right knee injury did not cause any temporary
exacerbations or any permanent material aggravation of those conditions.

[¶31] Ms. Valencia argues the Medical Commission erroneously relied on Triplett in
giving more weight to Dr. Nieves’ opinion than the opinions of Dr. Johnson and Dr.
Grunfeld. The Medical Commission determined Mr. Triplett had not met his burden of
showing that his right hip issues resulted from his work injury. Triplett, ¶¶ 24, 32, 497
P.3d at 909-910. In doing so, the Commission weighed the expert medical opinions on
causation but also relied, in part, on the fact that it had observed Mr. Triplett standing up
“three to four times during the hour [contested case] hearing, which indicated to the
[Commission] that the source of his pain was related more to the back [than] the hip as
persons suffering from hip pain do not generally find relief standing up, rather standing up
aggravates the hip pain.” Id., ¶ 31, 497 P.3d at 910 (emphasis omitted). We upheld the
Commission’s decision based on its weighing of the evidence, including the expert medical
opinions. Id., ¶¶ 41-45, 497 P.3d at 913-914. However, we found the Commission acted
inappropriately by independently diagnosing the source of Mr. Triplett’s pain. Id., ¶¶ 40-
41, 497 P.3d at 913. We explained that although “‘the Medical Commission is tasked with
weighing the medical and other evidence presented to it by the parties[,] [i]t is not tasked
with providing the equivalent of an independent medical examination and opinion.’” Id.,
¶ 40, 497 P.3d at 913 (quoting Worker’s Comp. Claim of Decker v. State ex rel. Wyo. Med.

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Comm’n, 2005 WY 160, ¶ 34, 124 P.3d 686, 697 (Wyo. 2005)) (emphasis omitted). In this
case, the Medical Commission relied on Triplett only to explain it was “mindful of the role
it has been assigned and the parameters of its decision-making authority.” The
Commission stuck to its role—weighing only the evidence presented to it and not forming
its own medical opinion.

[¶32] Ms. Valencia maintains the Medical Commission should have followed Salas v.
Gen. Chem., 2003 WY 79, 71 P.3d 708 (Wyo. 2003), and provided more weight to the
opinions of her treating physicians, Dr. Johnson and Dr. Grunfeld, than to the opinion of
Dr. Nieves. The hearing examiner, relying on the opinion of Mr. Salas’ treating physician,
determined Mr. Salas had met his burden of showing his workplace accident materially
aggravated his preexisting right knee condition. Salas, ¶ 8, 71 P.3d at 711. We determined
the treating physician’s opinion provided substantial evidence supporting the hearing
examiner’s decision. Id., ¶ 15, 71 P.3d at 714. Salas does not require a factfinder to rely
on the opinions of a claimant’s treating physician. Rather, we simply concluded the
factfinder’s reliance on the treating physician’s opinion in that case provided substantial
evidence supporting the factfinder’s decision. Mr. Salas’ treating physician opined that the
workplace accident materially aggravated his preexisting right knee condition. In contrast,
neither of Ms. Valencia’s treating physicians opined that her right knee injury or her altered
gait following that injury materially aggravated her preexisting left foot conditions.

[¶33] Ms. Valencia also maintains the Medical Commission erred by relying on Dr.
Nieves’ opinion because he stated her August 2020 right knee injury did not cause any
“permanent” material aggravation of a preexisting condition. According to Ms. Valencia,
our caselaw does not require a “permanent” material aggravation of a preexisting condition.
Citing Langberg, the Division maintains a material aggravation of a preexisting condition
requires a permanent worsening of the preexisting condition.

[¶34] Mr. Langberg’s treating physician testified that Mr. Langberg’s workplace injuries
“materially exacerbated” his preexisting condition. Langberg, ¶¶ 7, 18, 203 P.3d at 1100,
1102. Mr. Langberg argued this opinion satisfied his burden of showing a material
aggravation of a preexisting condition because “exacerbate” was synonymous with
“aggravate.” Id., ¶ 19, 203 P.3d at 19. The Division, on the other hand, argued the terms
did not have the same meaning. Id. In so arguing, it relied on the American Medical
Association Guides to the Evaluation of Permanent Impairment, which defined
“exacerbation” as a “[t]emporary worsening of a preexisting condition” and “aggravation”
as a “[p]ermanent worsening of a preexisting medical impairment.” Id., ¶ 23, 203 P.3d at
1103. We determined Mr. Langford’s treating physician was not using the term
“exacerbate” as defined by the Guides because the nature of Mr. Langford’s preexisting
condition as a progressive degenerative disease was not expected to return to baseline, i.e.,
it was not temporary. Id., ¶ 24, 203 P.3d at 1103. Instead, we found the treating physician
used the term “exacerbate” consistent “with its common dictionary definition—to increase
in severity.” Id., ¶ 25, 203 P.3d at 1103. We concluded the treating physician’s opinion

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was sufficient to establish Mr. Langford’s workplace injuries materially aggravated his
preexisting condition. Id., ¶ 26, 203 P.3d at 1103-04.

[¶35] We did not hold in Langberg that “aggravation” of a preexisting condition requires
a “permanent” worsening of the condition. The only question before us was Mr.
Langford’s treating physician’s intent when using the word “exacerbate.” In any event,
we need not decide here whether “aggravation” of a preexisting condition requires a
“permanent” worsening of the condition. Dr. Nieves opined not only that Ms. Valencia’s
right knee injury did not cause “any permanent material aggravation” of her preexisting
left foot conditions but also that her right knee injury did not cause “any temporary
exacerbations” of her preexisting left foot conditions.

[¶36] The Medical Commission’s decision that Ms. Valencia failed to meet her burden of
showing her altered gait following her right knee injury materially aggravated her
preexisting left foot conditions was supported by substantial evidence.

                                   CONCLUSION

[¶37] The Medical Commission’s decision that Ms. Valencia did not meet her burden of
showing her right knee injury or her altered gait following that injury caused a second
compensable injury to her left foot, ankle, and hammertoe or materially aggravated her
preexisting left foot conditions was supported by substantial evidence. We affirm.

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