Citation Nr: 21065015 Decision Date: 10/22/21 Archive Date: 10/22/21 DOCKET NO. 13-31 465A DATE: October 22, 2021 ORDER Entitlement to a disability rating in excess of 30 percent for status post left knee arthroplasty from May 1, 2015, is denied. Entitlement to a disability rating of 10 percent, and no higher, for mild instability of the left knee, status post left knee arthroplasty from February 2, 2016, is granted. Entitlement to service connection for an eye disability is denied. REMANDED Entitlement to service connection for a cervical spine disability, claimed as neck pain, is remanded. FINDINGS OF FACT 1. The Veteran's status post left knee arthroplasty from May 1, 2015 is manifest by limitation of range of motion no worse than intermediate degrees of residual weakness, pain or limitation of motion of flexion of 20 to 130 degrees, extension of 130 to 20 degrees, without ankylosis nor nonunion of tibia and fibula with loose motion, requiring a brace. 2. The Veteran's status post left knee arthroplasty is manifest by mild instability from February 2, 2016; with the occasional use of a brace, cane, or walker; but without a prescription by a medical provider for a brace, cane, or walker. 3. The preponderance of the evidence is against finding that the Veteran's eye disabilities began during active service, or is otherwise related to an in-service injury or disease. CONCLUSIONS OF LAW 1. The criteria for a rating in excess of 30 percent for status post left knee arthroplasty from May 1, 2015, have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5055, Diagnostic Code 5256, Diagnostic Code 5261, Diagnostic Code 5262. 2. The criteria for a rating of 10 percent and no higher for mild instability associated with status post left knee arthroplasty, from February 2, 2016, have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5257. 3. The criteria for service connection for eye disabilities are not met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the United States Air Force from November 1968 until his honorable discharge in August 1976. See August 1, 1976 Certificate of Release or Discharge From Active Duty (DD-214), box 18. The Veteran's primary military occupational specialty was an Education and Training Officer. Id, box 16a. The Veteran's secondary military occupational specialty was a pilot of strategic bombers, specifically Boeing B-52 Stratofortress aircraft. Id, box 17a. During the Veteran's service, he was awarded the Distinguished Flying Cross for flying four night bombing missions against heavily defended, vital military targets in North Vietnam and despite hostile fighter interceptors, numerous surface-to-air missiles, and high caliber antiaircraft artillery, penetrated these defenses and released his ordnance precisely on target. This appeal has been advanced on the Board's docket pursuant to 38 U.S.C. § 7107(a)(2); 38 C.F.R. § 20.900(c). These matters come before the Board of Veterans' Appeals (Board) on appeal from a June 2010 rating decision by the Jackson, Mississippi Regional Office (RO) of the United States Department of Veterans Affairs (VA). In November 2017 and July 2020, the Board remanded the case to the RO for further development. Specifically, the most recent Board remand directed the RO to obtain a VA opinion on the etiology of the Veteran's neck pain; obtain a VA opinion on the etiology of the Veteran's eye disability; and schedule the Veteran for a VA examination to ascertain the severity of his status post left knee arthroplasty. In response, the RO obtained VA examinations pertaining to the Veteran's neck disability in October 2020, to the Veteran's left knee in November 2020, and to the Veteran's eye disability in May 2021. Increased Rating Disability ratings are determined by applying the criteria set forth in the VA Schedule for Rating Disabilities (Schedule), found in 38 C.F.R. Part 4. The Schedule is primarily a guide in the evaluation of disability resulting from all types of diseases and injuries encountered as a result of or incident to military service. The ratings are intended to compensate, as far as can practicably be determined, the average impairment of earning capacity resulting from such diseases and injuries and their residual conditions in civilian occupations. 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Where there is a question as to which of two evaluations shall be applied, the higher evaluation will be assigned if the disability picture more nearly approximates the criteria for that rating. Otherwise, the lower rating will be assigned. 38 C.F.R. § 4.7. When reasonable doubt arises as to the degree of disability, such doubt will be resolved in the Veteran's favor. 38 C.F.R. § 4.3. In considering the severity of a disability, it is essential to trace the medical history of the Veteran. 38 C.F.R. §§ 4.1, 4.2, 4.41. Consideration of the whole-recorded history is necessary so that a rating may accurately reflect the elements of any disability present. 38 C.F.R. § 4.2; Peyton v. Derwinski, 1 Vet. App. 282 (1991). Although the regulations do not give past medical reports precedence over current findings, the Board is to consider the Veteran's medical history in determining the applicability of a higher rating for the entire period in which the appeal has been pending. Powell v. West, 13 Vet. App. 31, 34 (1999). Where entitlement to compensation has been established and an increase in the disability rating is at issue, the present level of disability is of primary concern. Francisco v. Brown, 7 Vet. App. 55, 58 (1994). Where an appeal is based on an initial rating for a disability, however, evidence contemporaneous with the claim and the initial rating decision are most probative of the degree of disability existing when the initial rating was assigned and should be the evidence "used to decide whether an original rating on appeal was erroneous." Fenderson v. West, 12 Vet. App. 119, 126 (1999). In either case, if later evidence indicates that the degree of disability increased or decreased following the assignment of the initial rating, staged ratings may be assigned for separate periods of time. Fenderson, 12 Vet. App. at 126; Hart v. Mansfield, 21 Vet. App. 505 (2007) (noting that staged ratings are appropriate whenever the factual findings show distinct time periods in which a disability exhibits symptoms that warrant different ratings). When adjudicating a claim for an increased initial evaluation, the relevant time period is from the date of the claim. Moore v. Nicholson, 21 Vet. App. 211, 215 (2007), rev'd in irrelevant part, Moore v. Shinseki, 555 F.3d 1369 (2009). When adjudicating an increased rating claim, the relevant time period for consideration is the time period one year before the claim was filed. Hart, 21 Vet. App. at 509. 1. Entitlement to a disability rating in excess of 30 percent for status post left knee arthroplasty from May 1, 2015 The Veteran asserts that he is entitled to a higher disability rating from May 1, 2015. During the pendency of the Veteran's appeal, VA issued a final rule revising the portion of the VA Schedule for Rating Disabilities that address the musculoskeletal system. 85 Fed. Reg. 76464 (November 30, 2020). The final rule went into effect February 7, 2021. Where there is a change in the rating criteria during the appeal period, the Board will consider the claim in light of both the former and revised schedular rating criteria, although an increased evaluation based on the revised criteria cannot predate the effective date of the amendments. Under both the former and revised criteria for Diagnostic Code 5055, prosthetic replacement of a knee joint is rated 100 percent for one year following implantation of the prosthesis. The one-year total rating commences after a one-month convalescent rating under 38 C.F.R. § 4.30. Thereafter, chronic residuals consisting of severe painful motion or weakness in the affected extremity warrant a 60 percent disability rating. Intermediate degrees of residual weakness, pain, or limitation of motion are rated by analogy. The minimum disability rating following replacement of a knee joint is 30 percent. 38 C.F.R. § 4.71a, Diagnostic Code 5055. Prior to the February 7, 2021 changes, the criteria for Diagnostic Code 5055, prosthetic replacement of a knee joint provides that for intermediate degrees of residual weakness, pain, or limitation of motion are rated by analogy to Diagnostic Codes 5256, 5260, 5261, or 5262. From the February 7, 2021 changes, the criteria for Diagnostic Code 5055, prosthetic replacement of a knee joint provides that for intermediate degrees of residual weakness, pain, or limitation of motion are rated by analogy to Diagnostic Codes 5256 through 5262. Specifically, this change adds the additional Diagnostic Codes of 5257, 5258, and 5259 to be inclusive and not rated as a separate disability rating. However, because the Veteran's claim predates the February 7, 2021 changes, separate disability ratings under Diagnostic Codes 5257, 5258, and 5259 shall still be considered for the Veteran's left knee disability. Under Diagnostic Code 5256, a 40 percent disability rating is available for ankylosis of the knee in flexion between 10 degrees and 20 degrees. A 50 percent disability rating is warranted for ankylosis of the knee in flexion between 20 degrees and 45 degrees. A 60 percent disability rating is assigned for extremely unfavorable ankylosis of the knee, in flexion at an angle of 45 degrees or more. 38 C.F.R. § 4.71a, Diagnostic Code 5256. Under Diagnostic Code 5257, other impairment of the knee with recurrent subluxation or lateral instability is assigned a 10 percent disability rating for slight findings, a 20 percent disability rating for moderate findings, and a 30 percent disability rating for severe findings. 38 C.F.R. § 4.71a, Diagnostic Code 5257. As noted above, from February 7, 2021, Diagnostic Code 5257 is inclusive within Diagnostic Code 5055. However, because the Veteran's disability rating predates the February 2021 changes, a separate disability rating must be considered and will be addressed below. Under Diagnostic Code 5258, a 20 percent disability rating is available for dislocated semilunar cartilage with frequent episodes of locking pain, and effusion into the joint. Under Diagnostic Code 5259, a 10 percent disability rating is warranted for removal of semilunar cartilage, symptomatic. 38 C.F.R. § 4.71a, Diagnostic Code 5258, Diagnostic Code 5259. The rating criteria provided for limitation of motion of the knee and leg are found at 38 C.F.R. § 4.71a, Diagnostic Code 5260 and Diagnostic Code 5261. Diagnostic Code 5260 provides disability ratings for limitation of flexion. Flexion of either leg limited to 60 degrees is noncompensable, flexion limited to 45 degrees merits a 10 percent disability rating, limitation of flexion to 30 degrees warrants a 20 percent evaluation, and a 30 percent evaluation requires that the flexion be limited to 15 degrees. Diagnostic Code 5261 provides disability ratings of 0 percent (noncompensable) for extension limited to 5 degrees, 10 percent for extension limited to 10 degrees, 20 percent for extension limited to 15 degrees, 30 percent for extension limited to 20 degrees, 40 percent for extension limited to 30 degrees, and a 50 percent disability rating for extension limited to 45 degrees. For rating purposes, normal range of motion of the knee is from zero to 140 degrees. See 38 C.F.R. § 4.71a, Plate II. Under Diagnostic Code 5262, a 40 percent disability rating is assigned for nonunion of the tibia and fibula with loose motion, requiring brace. 38 C.F.R. § 4.71a, Diagnostic Code 5262. VA General Counsel has provided guidance concerning increased rating claims for knee disorders. Separate disability ratings may be assigned distinct disabilities resulting from the same injury so long as the symptomatology for one condition was not "duplicative or overlapping with the symptomatology" of the other condition. Esteban v. Brown, 6 Vet. App. 259, 262 (1994). In VAOPGCPREC 9-98, the VA General Counsel also held that if a veteran has a disability rating under Diagnostic Code 5257 for instability of the knee, and there is also X-ray evidence of arthritis, a separate rating for arthritis could also be based on painful motion under 38 C.F.R. § 4.59. Given the findings of osteoarthritis, the General Counsel stated that the availability of a separate evaluation under Diagnostic Code 5003 in light of sections 4.40, 4.45, and 4.59 must be considered. Lichtenfels v. Derwinski, 1 Vet. App. 484, 488 (1991). Absent X-ray findings of arthritis, limitation of motion should be considered under Diagnostic Codes 5260 and 5261. Painful motion may add to the actual limitation of motion so as to warrant a rating under Diagnostic Codes 5260 or 5261. The VA General Counsel further noted in VAOPGCPREC 9-98 that the removal of the semilunar cartilage may involve restriction of movement caused by tears and displacements of the menisci, but that the procedure may result in complications such as reflex sympathetic dystrophy, which can produce loss of motion. Therefore, limitation of motion is a relevant consideration under Diagnostic Code 5259, and the provisions of 4.40, 4.45, and 4.59 must be considered. In addition, the VA General Counsel has held that separate ratings may be assigned under Diagnostic Code 5260 and Diagnostic Code 5261 for disability of the same joint. VAOPGCPREC 9-2004 (September 17, 2004). To give the Veteran every consideration in connection with the matters on appeal, the Board will also consider all other potentially applicable diagnostic codes under 38 C.F.R. § 4.71a in rating the Veteran's left and right knee disabilities during the appeal period. See, e.g., Butts v. Brown, 5 Vet. App. 532, 538 (1993) (the assignment of a particular diagnostic code is "completely dependent on the facts of a particular case"), and Pernorio v. Derwinski, 2 Vet. App. 625, 629 (1992) (one diagnostic code may be more appropriate than another based on such factors as the Veteran's relevant medical history, his current diagnosis, and demonstrated symptomatology). Disability of the musculoskeletal system is primarily the inability, due to damage or infection in the parts of the system, to perform the normal working movements of the body with normal excursion, strength, speed, coordination, and endurance. It is essential that the examinations on which ratings are based adequately portray the anatomical damage, and the functional loss, with respect to all these elements. The functional loss may be due to absence of part, or all, of the necessary bones, joints and muscles, or associated structures, or to deformity, adhesions, defective enervation, or other pathology, or it may be due to pain, supported by adequate pathology and evidenced by visible behavior of the claimant undertaking the motion. Weakness is as important as limitation of motion, and a part that becomes painful on use must be regarded as seriously disabled. 38 C.F.R. §§ 4.10, 4.40, 4.45. The Court has held that the RO must analyze the evidence of pain, weakened movement, excess fatigability, or incoordination and determine the level of associated functional loss in light of 38 C.F.R. § 4.40, which requires the VA to regard as "seriously disabled" any part of the musculoskeletal system that becomes painful on use. DeLuca v. Brown, 8 Vet. App. 202 (1995). The provisions of 38 C.F.R. § 4.14 (avoidance of pyramiding) do not forbid consideration of a higher rating based on greater limitation of motion due to pain on use, including during flare-ups. The Board notes that the guidance provided by the Court in DeLuca must be followed in adjudicating claims where a rating under the diagnostic codes governing limitation of motion should be considered. The Board further recognizes that the Court recently determined that pain alone does not constitute functional loss under VA regulations that evaluate disabilities based upon loss of motion. Mitchell v. Shinseki, 25 Vet. App. 32, 38 (2011). The intent of the rating schedule is to recognize painful motion with joint or periarticular pathology as productive of disability. Actually painful, unstable, or malaligned joints, due to healed injury, are as entitled to at least the minimum compensable rating for the joint. The joints should be tested for pain on both active and passive motion, in weight-bearing and nonweight-bearing and, if possible, with the range of the opposite undamaged joint. 38 C.F.R. § 4.59; see also Burton v. Shinseki, 25 Vet. App. 1 (2011) (holding that 38 C.F.R. § 4.59 is not limited to arthritis). Finally, in recent decisions, the Court held that the final sentence of 38 C.F.R. § 4.59 required that VA examination reports include joint testing for pain on both active and passive motion, in weight-bearing and nonweight-bearing and, if possible, with range of motion measurements of the opposite undamaged joint. Correia v. McDonald, 28 Vet. App. 158 (2016). The Court later explained that case law and VA guidelines anticipate that examiners will offer opinions as to additional functional loss during flare-ups of musculoskeletal disabilities based on estimates derived from information procured from relevant sources, including lay statements of veterans. It was noted that an examiner must do all that reasonably should be done to become informed before concluding that a requested opinion cannot be provided without resorting to speculation. Sharp v. Shulkin, 29 Vet. App. 26 (2017). For the time period, from May 1, 2015, the Board finds that a disability rating in excess of 30 percent is not warranted for status post left knee arthroplasty under 38 C.F.R. § 4.71a, Diagnostic Codes 5055, 5256, 5261, and 5262. The Board has considered entitlement to a higher disability rating under Diagnostic Codes 5256, 5261, and 5262, as directed by Diagnostic Code 5055. Extremely unfavorable ankylosis with limitation of flexion of 10 degrees or greater, limitation of extension of 30 degrees or greater, and nonunion of the tibia and fibula with loose motion, are simply not shown nor contended. The Veteran reported that he did all activities of daily living unassisted, but uses an assistive device only during a flare-up. As a preliminary matter, the Board notes that beginning with the February 2016 VA examination and continuing to the February 2017 and October 2020 VA examiners, slight instability of the left knee is documented during the VA examinations. Specifically, the February 2016 VA examiner found lateral instability 2+ (5-10 millimeters); and the February 2017 and October 2020 VA examiners found 1+ (0-5 millimeters). As noted above and will be addressed in greater detail below, this entitles the Veteran to service connection under a separate Diagnostic Code (Diagnostic Code 5257) due to his slight instability. The Veteran was afforded a VA examination in February 2016. During the February 2016 VA examination, the Veteran reported flare-ups of the right knee which requires him to take medication, sit down, uses warming gel, and takes Percocet 2-3 times daily. However, the Veteran reported that he did not need this for the left knee. Furthermore, the Veteran reported that his bilateral knee disabilities prevent him from running (as does his age of 73). However, the Veteran reported that he can use a treadmill while walking briskly, but does not squat due to his age, has a hard time standing after sitting for long periods, and prolonged walking and standing cause significant pain (but did not note functional limitations beyond pain). During the February 2016 VA examination, the Veteran's initial range of motion was flexion of 0 to 115 degrees and extension of 115 to 0 degrees in the right knee with no pain noted on the examination. The Veteran's initial range of motion was flexion of 0 to 130 degrees and extension of 130 to 0 degrees in the left knee with no pain noted on the examination. Furthermore, the February 2016 VA examiner found that there was no evidence of pain on weight bearing bilaterally, no objective evidence of localized tenderness or pain on palpation of the joint bilaterally, and no objective evidence of crepitus bilaterally. The Veteran did not have any additional loss of range of motion on repetitive use over time. Finally, the February 2016 VA examiner opined that they were unable to say without mere speculation if pain, weakness, fatigability or incoordination significantly limits the Veteran's functional ability without mere speculation because the examination did not occur during a flare-up. However, the Board notes that the February 2016 VA examination does not comply with the requirements in Sharp v. Shulkin, 29 Vet. App. 26, 34-36 (2017), a relevant case that was issued after this examination. The examiner did not attempt to elicit relevant information regarding the description of the Veteran's flare-ups and any additional functional loss suffered during flare-ups. Furthermore, while the examiner stated that an opinion could not be provided without resort to speculation, the examiner did not indicate that the speculation was due to lack of knowledge within the medical community. The Veteran was afforded a second VA examination in February 2017. During the February 2017 VA examination, the Veteran reported flare-ups of the right knee only. During the February 2017 VA examination, the Veteran's initial range of motion was flexion of 0 to 110 degrees and extension of 110 to 0 degrees in the right knee with no pain noted on the examination. The Veteran's initial range of motion was flexion of 0 to 115 degrees and extension of 115 to 0 degrees in the left knee with no pain noted on the examination. Furthermore, the March 2015 VA examiner found that there was no evidence of pain on weight bearing bilaterally, but there was objective evidence of localized tenderness to palpation of the joint bilaterally, and no objective evidence of crepitus bilaterally. The Veteran did not have any additional loss of range of motion on repetitive use over time. Finally, the February 2017 VA examiner opined that they were unable to say without mere speculation if the Veteran's disability worsens immediately after repetitive use over time because the examination was not conducted immediately following repeated use over time nor during a flare-up. However, the Board notes that, like the February 2016 VA examination, the February 2017 VA examination does not comply with the requirements in Sharp v. Shulkin, 29 Vet. App. 26, 34-36 (2017). The examiner did not attempt to elicit relevant information regarding the description of the Veteran's flare-ups and any additional functional loss suffered during flare-ups. Furthermore, while the examiner stated that an opinion could not be provided without resort to speculation, the examiner did not indicate that the speculation was due to lack of knowledge within the medical community. The Veteran's limitation of motion of the right knee also does not equate limitation of extension of the leg to 30 degrees and as a result, a higher disability rating under Diagnostic Code 5261 is also not warranted. In fact, evidence of record during this time period showed that the Veteran consistently demonstrated a range of motion no worse than of 0 to 110 (flexion) degrees and 110 to 0 degrees (extension). During VA examination reports dated February 2016, VA examiners each characterized the Veteran's left knee replacement residuals as intermediate degrees of residual weakness, pain, or limitation of motion. Finally, the February 2017 VA examiner also found that the Veteran had mild medial instability. The Veteran was afforded a third VA examination in October 2020. In contrast to the prior VA examinations, the October 2020 VA examiner provided an adequate VA examination. During the October 2020 VA examination, the Veteran reported that he experiences flare-ups once per month of severe pain when he stands for too long that last for the remainder of the day and sometimes into the next day. Furthermore, the Veteran reported that he cannot do anything that requires standing for a long period of time or requires him to be on his knees due to pain. The October 2020 VA examiner found that the Veteran had abnormal range of motion of 20 to 135 degrees of flexion and 135 to 20 degrees of extension for his initial range of motion of the right knee. The Veteran also had abnormal range of motion of 15 to 135 degrees of flexion and 135 to 15 degrees of extension for his initial range of motion for his left knee. As for repetitive use over time, the Veteran did not have additional functional limitation of range of motion due to repetitive use over time. During flare-ups, the Veteran reported flexion of 30 to 130 degrees and extension of 130 to 30 degrees for his right knee and flexion of 20 to 130 degrees and extension of 130 to 20 degrees for his left knee. The October 2020 VA examiner also noted that the Veteran did not have ankylosis, no history of subluxation, no lateral instability, but reported bilateral swelling a couple of times per month due to more intense activity. Evidence of record during the appeal period shows that the Veteran suffered from no more than intermediate degrees of residual weakness, pain or limitation of motion in the left knee that does not warrant the assignment of a disability rating in excess of 30 percent under Diagnostic Codes 5055, 5256, 5261, or 5262. The Board further finds that there is no basis for the assignment of any higher disability rating based on consideration of functional loss of the left knee during this time period. 38 C.F.R. §§ 4.40, 4.45, 4.59; Deluca, 8 Vet. App. at 204-06; Mitchell v. Shinseki, 25 Vet. App. 32, 38 (2011); Correia, 28 Vet. App. at 158. Even with the Veteran's assertions of pain, weakness, reduced range of motion, flare-ups, and functional limitation, he has not demonstrated limitation of extension or flexion of either knee to warrant the assignment of any higher evaluations. The evidence reflects that the currently assigned 30 percent disability rating properly compensates him for the extent of functional loss resulting from painful motion, fatigue, weakness, stiffness, and tenderness in the left and right knee, respectively. The Board has considered the findings regarding less movement than normal, weakened movement, excess fatigability, incoordination, pain on movement, and deformity. Here, however, the available medical findings do not show that painful motion, limitation of motion on repetitive use or during flare-ups, or pain or limitation of motion on active motion/passive motion/in weight-bearing/nonweight-bearing resulted in functional loss warranting the assignment of any higher evaluation during the appeal period. In this case, evidence of record showed no distinct periods of time during the appeal period when the Veteran's service-connected left knee disabilities varied to such an extent that a rating greater or less than the ratings currently assigned would be warranted. See Hart v. Mansfield, 21 Vet. App. 505 (2007). In reaching this decision the Board considered the doctrine of reasonable doubt, however, as the preponderance of the evidence is against the assignment of any additional higher evaluations for the Veteran's service-connected left and right knee disabilities, the doctrine is not for application. Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 2. Entitlement to a disability rating of 10 percent, and no higher, for mild instability of the left knee, status post left knee arthroplasty from February 2, 2016 The Veteran asserts that he is entitled to a higher disability rating for his left knee disability. As noted above, the record reflects that the Veteran's left knee, status post left knee arthroplasty has produced mild instability since February 2, 2016. Therefore, the Veteran is entitled to additional compensation under Diagnostic Code 5257, in addition to the above Diagnostic Code 5055 since February 2, 2016. The Veteran's mild instability of the left knee, status post left knee arthroplasty is rated under 38 C.F.R. § 4.71a, Diagnostic Code 5257, for other impairment of the knee. Under Diagnostic Code 5257, a 10 percent disability rating is warranted for slight recurrent subluxation or lateral instability. A 20 percent disability rating is warranted for moderate recurrent subluxation or lateral instability. A 30 percent disability rating is warranted for severe recurrent subluxation or lateral instability. 38 C.F.R. § 4.71a, Diagnostic Code 5257. According to MERRIAM WEBSTER'S COLLEGIATE DICTIONARY 999 (11th Ed. 2007), "slight" means small in amount. "Moderate" means limited in scope or effect. "Severe" means very painful or harmful or of a great degree. Objective medical evidence is not required to establish lateral knee instability under Diagnostic Code 5257, so objective medical evidence cannot be categorically found more probative than lay evidence with respect to this Diagnostic Code. See English v. Wilkie, 30 Vet. App. 347, 352-53 (2018). As noted above, effective February 7, 2021, VA amended the rating criteria for disabilities of the knee and leg. The amended Diagnostic Code 5257 provides ratings for other impairment of the knee based on recurrent subluxation or instability, and patellar instability. For recurrent subluxation or instability, a 10 percent rating is warranted for sprain, incomplete ligament tear, or complete ligament tear (repaired, unrepaired, or failed repair) causing persistent instability, without a prescription from a medical provider for an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A 20 percent rating is warranted for one of the following: (a) Sprain, incomplete ligament tear, or repaired complete ligament tear causing persistent instability, and a medical provider prescribes a brace and/or assistive device (e.g., cane(s), crutch(es), walker) for ambulation; or (b) Unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider prescribes either an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A maximum 30 percent rating is warranted for unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider prescribes both an assistive device (e.g., cane(s), crutch(es), walker) and bracing for ambulation. For patellar instability, a 10 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability (with or without history of surgical repair) that does not require a prescription from a medical provider for a brace, cane, or walker. A 20 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for one of the following: A brace, cane, or walker. A maximum 30 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for a brace and either a cane or a walker. Note (1) provides that, for patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note (2) provides that a surgical procedure that does not involve repair of one or more patellofemoral components that contribute to the underlying instability shall not qualify as a surgical repair for patellar instability (including, but not limited to, arthroscopy to remove loose bodies and joint aspiration).] Prior to February 7, 2021, the Board finds that the preponderance of the evidence is against a rating in excess of 10 percent for mild instability of the left knee, status post left knee arthroplasty. The Board has carefully considered the Veteran's reports about instability. English, 30 Vet. App. 347, 352-53. However, overall, the lay and medical evidence indicates that the instability symptoms have varied and do not suggest the presence of symptoms more nearly approximating moderate severity. From February 7, 2021, the Board finds that the preponderance of the evidence is against a rating in excess of 10 percent for mild instability of the left knee, status post left knee arthroplasty. The Board has carefully considered the Veteran's reports about instability. English, 30 Vet. App. 347, 352-53. However, overall, the lay and medical evidence indicates that although the Veteran occasionally uses an assistive device, he does not have a prescription for an assistive device. The Board has also considered the other Diagnostic Codes pertaining to the knee and leg. Other disability ratings may be assigned only if the symptomatology for a disability is not duplicative or overlapping with the symptomatology of any other disability. See Esteban v. Brown, 6 Vet. App. 259, 261-62 (1994); Lyles v. Shulkin, 29 Vet. App. 107 (2017) (holding that 38 C.F.R. § 4.14 prohibits paying compensation twice for the same symptoms or functional impairment). As noted above, consideration for assigning separate rating(s) for the Veteran's left knee, status post left knee arthroplasty has been addressed above, and resulted in a single additional disability rating. Specifically, mild instability of the left knee, status post left knee arthroplasty. In conclusion, the Board finds that the preponderance of the evidence is for the Veteran's claim for a disability rating of 10 percent for mild instability of the left knee, status post left knee arthroplasty from February 2, 2016. In denying such a rating, the Board finds the benefit of the doubt doctrine is not applicable. 38 U.S.C. § 5107; 38 C.F.R. §§ 4.3, 4.7. Service Connection Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a Veteran must show: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service - the so-called "nexus" requirement. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004)). Service connection may be granted for any disease initially diagnosed after discharge when all of the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). In addition, service connection for certain chronic diseases, including arthritis, may be established on a presumptive basis by showing that the condition manifested to a degree of 10 percent or more within one year from the date of separation from service. 38 U.S.C. §§ 1101, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.307, 3.309(a); Fountain v. McDonald, 27 Vet. App. 258, 271-72 (2015). Although the disease need not be diagnosed within the presumptive period, it must be shown, by acceptable lay or medical evidence, that there were characteristic manifestations of the disease to the required degree during that time. 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(a). Additionally, for certain chronic diseases with potential onset during service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. If chronicity in service is not established, a showing of continuity of symptoms after discharge may support the claim. 38 C.F.R. §§ 3.303(b), 3.309; Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Service connection may also be established on a secondary basis for a disability which is proximately due to, or the result of, a service-connected disability. 38 C.F.R. § 3.310(a). Secondary service connection may also be established for a disorder which is aggravated by a service-connected disability; compensation may be provided for the degree of the disability (but only that degree) over and above the degree of disability existing prior to the aggravation. 38 C.F.R. § 3.310(b) (2017); Allen v. Brown, 8 Vet. App. 374 (1995). 3. Entitlement to service connection for an eye disability The Veteran asserts that his eye disability began during service and has existed since that time and/or it is related to an in-service injury to the Veteran's right eyelid on July 10, 1972. Alternatively, the Veteran asserts that his eye disability is associated with his diagnosis of essential thrombocytosis. First, the Board finds that there is a current disability. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). The Veteran is diagnosed with bilateral vitreous degeneration, bilateral cataracts, and posterior vitreous detachment of the right eye. See January 2019 VA examination. Second, the Board finds that there was an in-service event, injury or disease. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). On July 10, 1972, the Veteran sustained a superficial laceration injury to his right eyelid during service. See July 10, 1972 service treatment records. Third, the Board finds that the evidence of record does not support a finding that the Veteran's eye disability is related to active service. The Veteran was afforded a VA examination in April 2019. The April 2019 VA examiner opined that the Veteran's current eye disabilities are less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness because the Veteran exhibits no residuals to either eye from fragment particles that entered the eyes during his time in service and the cornea and surface of each eye appear clear and normal, bilaterally. Furthermore, the Veteran's bilateral nuclear cataracts are solely age-related and not related to his time in service nor any injuries suffered to either eye at that time. Finally, the April 2019 VA examiner opined that the Veteran's bilateral vitreous floaters and posterior vitreous detachment are also age-related. The RO obtained an additional opinion from a different VA examiner in September 2020. The September 2020 VA examiner opined that the Veteran's current eye disabilities are less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness because there is no indication of association with military service or the incident which occurred on July 10, 1972. The September 2020 VA examiner also opined that the Veteran's current eye disabilities are less likely than not (less than 50 percent probability) proximately due to or the result of the Veteran's service-connected condition and that the claimed condition, which clearly and unmistakable existed prior to service, was clearly and unmistakably not aggravated beyond its natural progression by an in-service injury, event, or condition. The September 2020 VA examiner provided the same rationale for the last two opinions as the first. A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 301 (2008). The Board find that the above medical opinions are inadequate because they do not include supporting data nor a reasoned medical explanation connecting the two. However, in May 2021, the RO obtained an addendum opinion from the September 2020 VA examiner. In the May 2021 addendum opinion, the September 2020 VA examiner reaffirmed his negative nexus opinion and explained that a July 10, 1972 medical note from the United States Air Force hospital noted that the Veteran was testing a new pair of goggles when a fragment was thrown back toward the eyes which stated "no evidence for FB in eye," "cornea clear," and "impression of superficial laceration of right upper eyelid." See May 2021 VA examination; see also July 10, 1972 Service Treatment Records. Furthermore, the September 2020 VA examiner explained that the Veteran's diagnosed eye disabilities (bilateral vitreous degeneration, bilateral nuclear cataracts, and posterior vitreous detachment of the right eye) have no relationship to a superficial eye injury from 1972. The September 2020 VA examiner noted that onset of the Veteran's ocular conditions were first noted on the January 2019 Disability Benefits Questionnaire, [over] 40 years post military service and the July 1972 injury. Finally, the September 2020 VA examiner opined that the claimed herbicide agent exposure has no known direct relationship to bilateral vitreous degeneration, bilateral cataracts, nor posterior vitreous detachment of the right eye and there is no other evidence presented of onset, symptoms, or cause of the Veteran's ocular conditions presented during military service. Although the Board finds that the nexus opinions prior to the May 2021 addendum opinion to be inadequate, the final May 2021 addendum opinion is adequate, provides a clear rationale and addresses the Veteran's theories of entitlement. Accordingly, entitlement to service connection for an eye disability is denied. As to the Veteran's assertion that his diagnosed essential thrombocytosis has caused his eye disability, the Board notes that the Veteran is not currently service connected for essential thrombocytosis and therefore, even if the evidence showed that his essential thrombocytosis caused or aggravated the Veteran's eye disabilities beyond their natural progression, it would not give rise to service connection for his eye disabilities, because he is not service connected for essential thrombocytosis. In reaching this decision the Board considered the doctrine of reasonable doubt, however, as the preponderance of the evidence is against the Veteran's claim, the doctrine is not for application. Gilbert v. Derwinski, 1 Vet. App. 49 (1990). REASONS FOR REMAND 4. Entitlement to service connection for a cervical spine disability, claimed as neck pain, is remanded. The Veteran asserts that severe neck pain began during service and has existed since that time and/or it is related to an in-service flying fighter jets and neck compression "due to pulling 5-7 [or 6-8, depending on the statement] G's." In April 2010, the Veteran submitted a Statement in Support of Claim (VA Form 21-4138) with an attached narrative in which he asserts that he attributes to having "flown fighter type airplanes...that continually pulling 5-7 G's compressed my neck vertebrates to the point that I have pain." Within the Veteran's June 2010 Notice of Disagreement, the Veteran asserts that "...wearing a 10-pound flight helmet and experiencing 6-8 G's for an extended period of time (months, years) would more than likely cause neck vertebrae to compress and result in subsequent neck pain thereafter." Where VA provides the veteran with an examination in a service connection claim, the examination must be adequate. Barr v. Nicholson, 21 Vet. App. 303, 311 (2007). Generally, a medical opinion should address the appropriate theories of entitlement. Stefl v. Nicholson, 21 Vet. App. 120, 123-24 (2007). However, the Board notes that no VA examiner has offered an opinion to these theories of entitlement, specifically that pulling 5-8 G's with a 10-pound flight helmet would at least as likely as not (50 percent probability or greater) cause the Veteran's neck disability. As noted above, the Veteran's military personnel records show that he was a B-52 heavy bomber aircraft pilot. However, the record does not reflect the Veteran's experience in "fighter type" aircraft and remand for additional information and possibly additional service personnel records is required. The Veteran indicated that his disability may be related to "[flying] fighter type airplanes...that continually pulling 5-7 G's [or 6-8 G's] compressed my neck vertebrates to the point that I have pain," and "...wearing a 10-pound flight helmet and experiencing 6-8 G's for an extended period of time (months, years)." However, all records within the file reflect that the Veteran was a pilot of a B-52, not "fighter type aircraft," that the Veteran asserts subjected him to "months, years" of 5-8 G-Forces. The AOJ should attempt to verify the Veteran's flight experience to confirm. Finally, if there are missing records, they may contain more detailed information regarding the Veteran's flight experiences, a remand is required to obtain them. The matters are REMANDED for the following action: 1. Request a written statement from the Veteran detailing his experiences in "fighter type aircraft" in which he asserts he pulled 5-8 g-forces for "months, years." The Veteran should include the aircraft type flown, the dates (or periods of time) in which he flew each aircraft, the number of hours flown in each aircraft, and detail the experiences in these aircraft that he asserts caused his neck disabilities including but not limited to any specific events. The Veteran should also provide the date and details of the motor vehicle accident in which resulted in the aggravation of his neck disability. 2. If it is determined that any service personnel records or service treatment records are missing (to corroborate the Veteran's assertions), obtain the Veteran's complete service personnel records and/or service treatment records. 3. After any additional records (including any missing service treatment records, if any) are associated with the claims file, obtain an addendum opinion regarding the etiology of the Veteran's neck disability from a VA examiner, including consideration of the above requested statement(s). The entire claims file must be made available to and be reviewed by the examiner. If an examination is deemed necessary, it shall be provided. An explanation for all opinions expressed must be provided. The examiner must provide an opinion regarding whether it is at least as likely as not (50 percent or greater probability) that the Veteran's neck disability had onset in, or is otherwise related to, active service. The examiner must specifically address the Veteran's theory of entitlement. Specifically, that his flight experiences (10-pound helmet and high g-force experience) caused his neck disability. The examiner must also consider the remaining evidence of record, including the Veteran's service treatment records, separation evaluation, and post-service treatment records in the nexus opinion. M. Tenner Veterans Law Judge Board of Veterans' Appeals Attorney for the Board G. Deemer, Associate Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.