Citation Nr: 21025883 Decision Date: 04/29/21 Archive Date: 04/29/21 DOCKET NO. 16-22 444 DATE: April 29, 2021 ORDER A rating of more than 10 percent since February 29, 2012 for limited left knee flexion is denied. A separate 10 percent rating for patellar instability of the left knee is granted, effective February 29, 2012. A separate 20 percent rating for frequent episodes of “locking” and effusion of the left knee is granted, effective February 29, 2012. Service connection for a right knee disorder, to include as secondary to a left knee disorder, is denied. Service connection for a right hip disorder, to include as secondary to a left knee disorder, is denied. Service connection for a lower back disorder, to include as secondary to a left knee disorder, is denied. Service connection for a right foot disorder, to include as secondary to a left knee disorder, is denied. REMAND The issue of a total disability rating based on unemployability (TDIU) on an extraschedular basis is remanded. FINDINGS OF FACT 1. Since February 29, 2012, the Veteran’s left knee disorder manifests with a diagnosed condition involving the patellofemoral complex with recurrent instability that did not require surgical repair; flare-ups; difficulty with prolonged bending, standing, walking, and weightbearing; recurrent and severe instability; frequent swelling and “locking” episodes resulting in falling; flexion limited to 90 degrees, painful flexion, and normal extension. 2. The probative medical evidence indicates the Veteran’s right knee disorder is not causally related to his service-connected left knee disorder, was not chronic in service, did not manifest to a compensable degree within one year of separation, and is not otherwise related to service. 3. The probative medical evidence indicates the Veteran’s right hip disorder is not causally related to his service-connected left knee disorder and is not otherwise related to service. 4. The probative medical evidence indicates the Veteran’s lower back disorder is not causally related to his service-connected left knee disorder and is not otherwise related to service. 5. The probative medical evidence indicates the Veteran’s right foot disorder is not causally related to his service-connected left knee disorder and is not otherwise related to service. CONCLUSIONS OF LAW 1. Since February 29, 2012, the criteria for a rating of more than 10 percent for limited flexion of the left knee have not been met. 38 U.S.C. §§ 1155, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 3.326 (a), 4.7, 4.10, 4.14, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code (DC) 5260. 2. Since February 29, 2012, the criteria for a separate 10 percent rating, but no higher, for patellar instability of the left knee have been approximated. 38 U.S.C. §§ 1155, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 3.326 (a), 4.7, 4.10, 4.14, 4.40, 4.45, 4.59, 4.71a, DC 5257. 3. Since February 29, 2012, the criteria for a separate 20 percent rating for locking and effusion of the left knee have been approximated. 38 U.S.C. §§ 1155, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 3.326 (a), 4.7, 4.10, 4.14, 4.40, 4.45, 4.59, 4.71a, DC 5258. 4. The criteria to establish service connection for a right knee disorder secondary to a left knee disorder have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.309, 3.310. 5. The criteria to establish service connection for a right hip disorder secondary to a left knee disorder have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.309, 3.310. 6. The criteria to establish service connection for a lower back disorder secondary to a left knee disorder have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.309, 3.310. 7. The criteria to establish service connection for a right foot disorder secondary to a left knee disorder have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.309, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran had active service from June 1974 to June 1977. In April 2019, the Veteran was afforded a videoconference hearing before the undersigned Veterans Law Judge (VLJ). During the hearing, the VLJ engaged in a colloquy with the Veteran toward substantiation of the claims. Bryant v. Shinseki, 23 Vet. App. 488, 496-97 (2010). A hearing transcript is in the record. In October 2019, the Board of Veterans’ Appeals (Board) remanded this matter for an additional VA examination and medical opinions, which were completed in January 2020. Review of the completed development reveals that substantial compliance with the remand directives was obtained. Stegall v. West, 11 Vet. App. 268 (1998). 1. Entitlement to a rating of more than 10 percent since February 29, 2012 for a left knee disorder. Disability ratings are determined by applying criteria set forth in VA’s Schedule for Rating Disabilities. Ratings are based on the average impairment of earning capacity. Individual disabilities are assigned separate diagnostic codes (DCs). See 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Where there is a question as to which of two evaluations should be applied, the higher evaluation will be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. See 38 C.F.R. § 4.7. VA assesses the level of disability from up to a year prior to the date of application for an increased rating and determines whether the level of disability warrants the assignment of different disability ratings at different times over the course of the claim, a practice known as “staged ratings.” See Fenderson v. West, 12 Vet. App. 119, 126 (1999); see also Hart v. Mansfield, 21 Vet. App. 505, 509-10 (2007) (holding that staged ratings may be warranted in increased rating claims). Here, VA received the Veteran’s application for an increased rating on February 29, 2012. Additionally, the evaluation of the same disability under several diagnostic codes, known as pyramiding, must be avoided. Separate ratings may be assigned for distinct disabilities resulting from the same injury so long as the symptomatology for one condition is not duplicative of or overlapping with the symptomatology of the other condition. 38 C.F.R. § 4.14; Esteban v. Brown, 6 Vet. App. 259, 262 (1994). 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 examination 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 innervation, 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 which becomes painful on use must be regarded as seriously disabled. 38 C.F.R. §§ 4.10, 4.40, 4.45, 4.59. Provision 38 C.F.R. § 4.40 allows for consideration of functional loss due to pain and weakness causing additional disability beyond that reflected on range of motion measurements. Under 38 C.F.R. § 4.45, functional loss due to weakened movement, excess fatigability, and incoordination must also be considered. See DeLuca v. Brown, 8 Vet. App. 202, 206-07 (1995) (holding that the criteria discussed in sections 4.40 and 4.45 are not subsumed by the DCs applicable to the affected joint). The provisions of 38 C.F.R. § 4.59 recognize that painful motion is an important factor of disability. Joints that are painful, unstable, misaligned, or due to healed injury are entitled to at least the minimum compensable rating for the joint. Id. Special note should be taken of objective indications of pain on pressure or manipulation, muscle spasm, crepitation, and active and passive range of motion of both the damaged joint and the opposite undamaged joint. Id.; see Burton v. Shinseki, 25 Vet. App. 1 (2011) (holding that § 4.59 applies to all forms of painful motion of joints, and not just to arthritis). In deciding claims, it is the Board’s responsibility to evaluate the entire record on appeal. See 38 U.S.C. § 7104 (a). Although the Board has an obligation to provide reasons and bases supporting this decision, there is no need to discuss every piece of evidence submitted by the Veteran or on his behalf. See Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000). Rather, the Board’s analysis below will focus specifically on what evidence is needed to substantiate the claims and what the evidence in the claims file shows, or fails to show, with respect to the claims. See Timberlake v. Gober, 14 Vet. App. 122, 128-30 (2000). In assigning a higher disability rating, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the Veteran prevailing in either event, or whether a preponderance of the evidence is against the claim, in which case the claim is denied. 38 U.S.C. § 5107; 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). Throughout the rating period on appeal, the Veteran’s left knee chondromalacia has been assigned a 10 percent rating based on painful flexion of the knee. See 38 C.F.R. § 4.59, DC 5260. He contends his symptoms have worsened and a higher rating is warranted. DC 5260 provides ratings based on limitation of flexion of the leg. Limitation of flexion to 60 degrees warrants a noncompensable rating. Limitation of flexion to 45 degrees warrants a 10 percent rating. Flexion limited to 30 degrees warrants a 20 percent rating. Flexion limited to 15 degrees warrants a 30 percent rating. 38 C.F.R. § 4.71a, DC 5260. DC 5257 was amended, effective February 7, 2021, and now provides ratings for “recurrent subluxation or instability” or “patellar instability.” With respect to patellar instability, DC 5257 provides: A 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; 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; and 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. See 38 C.F.R. § 4.71a, DC 5257. Note 1 to DC 5257 provides that, for patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note 2 to DC 5257 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 surgical repair for patellar instability (including, but not limited to, arthroscopy to remove loose bodies and joint aspiration). In an April 2011 VA treatment record, the Veteran reported chronic, intermittent medial left knee pain. He reported his left knee occasionally “gave out” while climbing stairs. On physical examination, the Veteran’s gait was coordinated and smooth and the examiner indicated there was no evidence of clubbing, misalignment, or deformities of the bones, joints, or muscles. The Veteran had normal left knee range of motion (ROM) with no pain or contractures (fixed tightening of muscle, tendons, ligaments, or skin). A June 2011 VA MRI (magnetic resonance imaging) report indicated mild medial compartment narrowing consistent with degenerative changes of the left knee. The MRI report indicated there was no evidence of fracture or dislocation, soft tissues were unremarkable, and other joint spaces were preserved. In a June 2011 VA physical therapy note, the Veteran reported left knee pain while standing, walking, and negotiating stairs. On physical examination, his ROM was within normal limits. A VA physical therapist indicated the Veteran would benefit from a brace and prescribed him a left knee brace. A January 2012 VA treatment record reports that the Veteran had an antalgic gait (a shortened gait due to pain) associated with his right hip disorder. He continued to report left knee pain and inquired about assistive devices to help with painful weightbearing. A VA physical therapist prescribed a single point cane and noted the Veteran’s gait improved while using it. At the May 2012 VA knee examination, the Veteran reported that he initially injured his left knee in 1976, spent three weeks in the hospital, and declined exploratory surgery at that time. He indicated that after separating from service, he was able to perform various jobs but still had left knee pain and swelling. He stated he had been scheduled for arthroscopic surgery in 1999 but the surgery was cancelled. The Veteran denied any surgeries, hospitalizations, or emergency room (ER) visits for his left knee condition. He indicated he regularly wore a knee brace and took Ibuprofen to alleviate symptoms. The Veteran also indicated he used a cane due to his right hip condition. The Veteran reported his left knee and other joint problems impacted his ability to work, causing difficulty with lifting, bending, stooping, climbing, and prolonged standing and walking. He denied flare-ups. On initial ROM testing, the Veteran had left knee flexion to 130 degrees with pain, and normal left knee extension without pain. The Veteran was able to perform repetitive use testing without any additional loss of ROM or pain. Muscle strength and joint stability were normal and the Veteran did not have ankylosis or muscle atrophy. The Veteran denied a history of recurrent patellar subluxation (partial dislocation of the kneecap). The examiner indicated there was no evidence of redness, heat, swelling, inflammation, or deformity in either knee. The examiner indicated that X-rays taken at the examination revealed traumatic or degenerative arthritis but were negative for patellar subluxation. The May 2012 VA examiner noted diagnoses of left knee chondromalacia and a left medial meniscus tear. She indicated the left meniscal tear was definitively diagnosed in 1997 based on MRI taken at that time, and opined the meniscal tear was separate and unrelated to the Veteran’s service-connected chondromalacia. She explained that the two conditions both cause knee pain, but manifest with different symptoms. The examiner explained that chondromalacia usually causes pain while climbing stairs, where meniscus pain usually occurs with weightbearing or ambulation. She also noted that chondromalacia patella affects the kneecap bone and does not cause cartilage tears. The examiner further opined that the Veteran’s meniscal condition was likely related to trauma and weight gain during the 20-year period between service separation and the 1997 meniscus tear. Based on this evidence, the examiner concluded the Veteran’s severe left knee pain was mostly from the non-service-connected meniscal tear. In an October 2012 VA primary care record, the Veteran reported increased left knee pain, “buckling” once per day, difficulty climbing stairs, and swelling. He reported falling at least once. On physical examination, the Veteran demonstrated crepitus, mild effusion, and abnormal ROM. He was noted to have a normal gait at that time. X-rays taken in November 2012 indicated mild osteoarthritis in the left knee. In a January 2013 treatment record, the Veteran reported minimal and occasional swelling of the left knee and denied using ice to alleviate pain. An April 2013 treatment record reports that the Veteran was classified as a “high risk for falls” due to his reports of falling twice or more in the previous six months. The attending clinician noted the Veteran had a gait deficit and used a cane and knee brace for stability. Treatment records from September 2013 to November 2013 indicate that the Veteran reported increasing left knee pain at an “8/10” in severity. He reported the pain continued to increase after receiving a left knee injection, stating “everything makes it worse, nothing makes it better.” In an April 2015 pain assessment note, the Veteran reported a “crawling” sensation in the back of his left leg that radiated down his knee and lower extremity. He continued to report left knee pain that ranged from 4/10 to 8/10 in severity. The attending clinician reviewed January 2015 X rays and noted the Veteran’s mild osteoarthritis was stable and essentially unchanged, with no acute findings present. The clinician noted there was no evidence of joint effusion, fracture, or dislocation. She indicated the Veteran’s primary limitations were walking and standing activities. In a May 2015 orthopedic evaluation, the Veteran demonstrated left knee flexion to 125 degrees with no crepitus, joint line tenderness, instability, or effusion. He was noted to have tenderness of the medial patellar facet and “OK” patellar tracking. The attending physician noted the Veteran had increased pain with bent knee loading, climbing stairs, and walking, but no mechanical symptoms. The clinician also noted the Veteran previously received steroid injections in his left knee. A December 2015 VA physical therapy (PT) record indicates that the Veteran had “moderately good” relief from his left knee pain after PT. On physical examination, the Veteran had mild synovial thickening, mild tenderness with compression, mild medial joint line tenderness, and left knee flexion to 90 degrees. The attending physician noted the Veteran did not have instability, effusion, or crepitus, and patellar tracking was normal. At the April 2019 Board hearing, the Veteran continued to report that his left knee pain had worsened since the May 2012 VA examination. He reported he could not help his wife with errands such as shopping because of inability to walk or stand for prolonged periods. He reported that occasionally his bilateral knee pain is so severe that he is forced to stay in bed and elevate his legs. The Veteran stated he could not sit with his knees bent and must extend them. He reported that, approximately once or twice a week, he has episodes where his left knee “locks” or “freezes” while walking, causing him to fall. He indicated he had always had this problem. He stated he cannot walk more than half a block without needing to rest for 20 minutes. The Veteran testified that he is unable to climb stairs and has difficulty entering vehicles, requiring a safety bar to do so. In May 2019, the Veteran submitted a Disability Benefits Questionnaire (DBQ) completed by a non-VA physician. The physician indicated diagnoses of left knee osteoarthritis in June 2011, and a left meniscal tear diagnosed by MRI in June 1997. The physician noted the Veteran’s 1976 left knee injury but did not reference the diagnosis of chondromalacia patella. At the examination, the Veteran reported flare-ups that caused pain while walking, standing, or bending. He continued to report swelling and buckling of the knees during physical activity. During ROM testing, he had left knee flexion to 120 degrees with pain, and normal extension. The examiner indicated the Veteran had pain with weight-bearing and non-weight bearing and during active and passive ROM testing. The Veteran was able to perform repetitive use testing without any additional loss of ROM or pain. The Veteran did not have localized tenderness or pain to palpation in the left knee, although crepitus was noted. The May 2019 examiner listed additional contributing factors including less movement than normal, weakened movement, excess fatigability, incoordination, pain on movement, swelling, disturbance of locomotion, and interference with sitting and standing. The examiner opined that pain, weakness, fatigability, or incoordination could significantly limit functional ability during flare-ups or after repeated use over time. He reiterated that use of the left knee caused increased pain and decreasing function that was not associated with limitation of motion alone. The examiner opined the Veteran’s ability to work would be limited due to his inability to stand or walk for any significant period. Additional testing indicated reduced muscle strength in both knees, but no muscle atrophy or ankylosis. The examiner noted the Veteran’s history of moderate bilateral knee swelling with use of the knees. The examiner indicated there was no history of lateral instability or recurrent subluxation and did not perform joint stability testing. However, the examiner noted the Veteran’s previous left knee meniscal condition with symptoms of frequent episodes of “locking,” joint pain, and effusion. At the January 2020 VA examination, the Veteran continued to report pain under his left kneecap and that his left knee occasionally gave out after standing for long periods of time. He reported flare-ups that occur during certain movements of the knee and during long periods of weight bearing. The VA examiner noted diagnoses of left knee chondromalacia, left knee degenerative joint disease (DJD) and a left meniscal tear. She noted that peer-reviewed orthopedic literature indicates that meniscal tear and DJD are “not the same” as chondromalacia. The examiner noted the Veteran’s DJD and meniscal tear were diagnosed approximately 20 years after service and concluded those conditions were unrelated to service. The examiner stated that the Veteran’s medical history contained discussion of patellofemoral syndrome and patella alta, which can also cause pain in the knee. However, based on medical literature, she concluded the Veteran’s current left knee signs and symptoms were more likely than not due to his degenerative left knee conditions. Initial ROM testing revealed left knee flexion to 120 degrees and normal extension. The examiner noted there was no evidence of pain during ROM testing and that abnormal ROM did not contribute to functional loss. There was no evidence of pain with weight bearing, non-weight bearing, localized tenderness, or crepitus. The examiner noted that passive and active ROM testing were the same, bilaterally, and there was no objective evidence of pain when the right knee (contralateral joint) was used in non-weightbearing. The Veteran was able to complete repetitive use testing without any additional functional loss or reduction in ROM. The examiner indicated the Veteran was not examined immediately after repeated use over a period time, but opined the examination was medically consistent with the Veteran’s statements describing functional loss with repetitive use. However, the examiner opined that pain, weakness, fatigability, or incoordination would not significantly limit functional ability with repeated use over time, or during a flare-up. Additional testing indicated normal muscle strength and joint stability, and the Veteran did not have ankylosis or muscle atrophy. The examiner noted the Veteran had leg length discrepancy, with the right leg being 1cm shorter than the left. She noted that based on the Veteran’s history and medical literature, the leg length discrepancy was most likely to due to the Veteran’s right hip arthroplasty. Since February 29, 2012, the Veteran reported flare-ups; difficulty with prolonged bending, standing, walking, and weightbearing; occasional swelling; episodes of knee “locking” and/or “giving way” resulting in falling; flexion limited to 90 degrees, painful flexion, and normal extension. His left knee flexion has not been limited to 45 degrees. At worst, his left knee flexion was measured at 90 degrees in December 2015. However, given the Veteran’s painful flexion and additional functional impairment during flare-ups, the minimum 10 percent rating already in effect is appropriate. 38 C.F.R. § 4.71a, DC 5260. See 38 C.F.R. § 4.59, Deluca, supra. The medical evidence is in relative equipoise as to whether (and which of) the Veteran’s current left knee symptoms stem from his service-connected chondromalacia. As noted above, the May 2012 and January 2020 VA examiners concluded the Veteran’s most severe left knee symptoms were caused by DJD and a 1997 meniscal tear which are not service-connected. The VA opinions relied on medical literature and provided a general explanation of the difference between chondromalacia, DJD, and meniscal tears. With respect to specific symptoms, the VA examiners’ discussion was limited to the different circumstances which cause pain. However, the examiners did not specifically explain why the Veteran’s swelling, buckling and instability was not related to his chondromalacia. Additionally, the VA examiners did not address the Veteran’s credible reports of swelling, buckling and instability before being diagnosed with DJD and a meniscal tear. The Board will resolve any doubt in the Veteran’s favor and award an additional, separate 10 percent rating under DC 5257 based on patellar instability. The Veteran’s chondromalacia patella is “a diagnosed condition involving the patellofemoral complex.” He has consistently reported recurrent left knee instability through and has been prescribed a cane and knee brace throughout the rating period. At the April 2019 hearing, he testified that he was essentially unable to walk or stand for any significant period without his left knee giving out. Given this evidence a 10 percent rating is approximated. A rating of more than 10 percent is not warranted for “patellar instability” under DC 5257. The next highest rating requires “surgical repair of a condition involving the patellofemoral complex.” While the Veteran received steroid injections in his left knee during the rating period, procedures that do not involve repair of one or more patellofemoral components that contribute to the underlying instability do not qualify as “surgical repair for patellar instability.” See 38 C.F.R. § 4.71a, DC 5257, Note (2). Although the Veteran has been prescribed a cane and knee brace during the rating period, a rating of more than 10 percent cannot be awarded absent evidence of surgical repair. Id. Further, a rating of more than 10 percent under the alternate criteria for “recurrent subluxation and instability” under DC 5257 is not warranted. The Veteran does not meet the criteria for the next higher rating because the evidence does not show that he has had either a left knee “sprain, incomplete ligament tear, or repaired complete ligament tear,” or a “Unrepaired or failed repair of complete ligament tear.” See 38 C.F.R. § 4.71a, DC 5257. While the Veteran had a left meniscal condition documented by MRI in 1993 and 1997, he opted not to undergo surgery to correct that condition. Later X-rays and MRI have not shown evidence of any ligament tear. The Veteran’s symptoms of left knee swelling and “locking” warrant an additional, separate rating under DC 5258. See 38 C.F.R. § 4.71a, DC 5258. DC 5258 provides a single, maximum 20 percent rating for dislocated semilunar cartilage (meniscus) with frequent episodes of “locking,” pain, and effusion to the joint. The Veteran has consistently reported swelling and frequent locking episodes and no medical provider has thoroughly explained why these symptoms are not caused by his service-connected chondromalacia. Board will resolve any doubt in the Veteran’s favor and award a separate 20 percent rating under DC 5258. This is the highest possible rating under this diagnostic code. The remaining DCs applicable to the knee do not warrant any additional separate ratings. A separate rating under DC 5256 is not warranted because no medical provider has found evidence of ankylosis and the Veteran has consistently demonstrated a range of motion in the left knee. 38 C.F.R. § 4.71a, DC 5256. His reports of knee “locking” and “freezing” are compensated as outlined above. A separate rating under DC 5259 for removal of semilunar cartilage is not warranted. While the evidence is in relative equipoise as to whether the 1997 meniscal tear contributes to the Veteran’s current symptoms, the Board has resolved this in the Veteran’s favor. However, the May 2019 private examiner opined the Veteran’s meniscus-related symptoms included effusion, locking, and pain—all of which have been compensated by the ratings assigned above. There is no basis to award an additional rating for a meniscal surgery or similar symptoms as provided in DC 5259. A separate rating under DC 5261 for limitation of extension is not warranted because the Veteran’s left knee has consistently demonstrated normal extension and has not reported painful extension during ROM testing. 38 C.F.R. § 4.71a, DC 5261. A separate rating under DC 5262 for tibia or fibula impairment is not warranted as there was no evidence of nonunion or malunion of the tibia or fibula. 38 C.F.R. § 4.71a, DC 5262. A separate rating under DC 5263 is not warranted because the Veteran has never had genu recurvatum (a deformity of the knee joint resulting in the knee being bent backwards). 38 C.F.R. § 4.71a, DC 5263. For these reasons, a rating of more than 10 percent under DC 5260 for limited flexion of the left knee is not warranted at any point during the appellate period. However, the Board will grant two (2) separate 20 percent ratings under DCs 5257 and 5258, effective February 29, 2012, the date the Veteran’s application for an increased rating was received. Service Connection Service connection may be granted for a disability resulting from a disease or injury incurred in or aggravated by service. See 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. 2010) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004)). Disorders diagnosed after discharge will still be service connected if all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303 (d); see Combee v. Brown, 34 F.3d 1039, 1043 (Fed. Cir. 1994). Service connection may be established on a secondary basis for a disability which is proximately due to or the result of a service-connected disease or injury. 38 C.F.R. § 3.310 (a). Additional disability resulting from the aggravation of a nonservice-connected condition by a service-connected condition is also compensable under 38 C.F.R. § 3.310 (b). See Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc). Certain disorders, listed as “chronic” in 38 C.F.R. § 3.309 (a) and 38 C.F.R. § 3.303 (b), are capable of service connection based on a continuity of symptomatology without respect to an established causal nexus to service. See Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). DJD is a type of arthritis, which is among the diseases listed under 38 C.F.R. § 3.309 (a). Therefore, the presumptive service connection provisions based on “chronic” in-service symptoms and “continuous” post-service symptoms under 38 C.F.R. § 3.303 (b) apply. Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Where the evidence shows a “chronic disease” in service or “continuity of symptoms” after service, the disease shall be presumed to have been incurred in service. 38 C.F.R. § 3.303 (b). Additionally, where a veteran served ninety days or more of active service, and certain chronic diseases, such as arthritis, become manifest to a degree of 10 percent or more within one year after the date of separation from such service, such disease shall be presumed to have been incurred in service, even though there is no evidence of such disease during the period of service. 38 U.S.C. §§ 1101, 1112, 1113, 1137; 38 C.F.R. §§ 3.307, 3.309 (a). While 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. Id. In deciding an appeal, the Board must analyze the credibility and probative value of the evidence, account for the evidence which it finds to be persuasive or unpersuasive, and provide the reasons for its rejection of any material favorable to the claimant. Gabrielson v. Brown, 7 Vet. App. 36, 39-40 (1994); Gilbert v. Derwinski, 1 Vet. App. 49, 57 (1990). Competency is a legal concept determining whether testimony may be heard and considered by the trier of fact, while credibility is a factual determination about the probative value of the evidence to be made after the evidence has been admitted. Rucker v. Brown, 10 Vet. App. 67, 74 (1997); Layno v. Brown, 6 Vet. App. 465, 469 (1994). When considering whether lay evidence is competent, the Board must determine, on a case-by-case basis, whether a veteran’s disability is the type of disability for which lay evidence may be competent. Kahana v. Shinseki, 24 Vet. App. 428 (2011); see also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). A veteran is competent to report symptoms because this requires only personal knowledge, not medical expertise, as it comes to him through his senses. See Layno, 6 Vet. App. 465, 469. Lay testimony is competent to establish the presence of observable symptomatology, where the determination is not medical in nature and is capable of lay observation. Barr v. Nicholson, 21 Vet. App. 303 (2007). Lay evidence may establish a diagnosis of a simple medical condition, a contemporaneous medical diagnosis, or symptoms that later support a diagnosis by a medical professional. Jandreau, 492 F.3d 1372, 1377. In deciding claims, it is the Board’s responsibility to evaluate the entire record on appeal. See 38 U.S.C. § 7104 (a). When all the evidence is assembled, the Board is then responsible for determining whether the evidence supports the claim or is in relative equipoise, with the Veteran prevailing in either event, or whether the preponderance of the evidence is against the claim, in which case the claim is denied. 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 2. Service connection for a right knee disorder, including as secondary to a left knee disorder. The Veteran contends his current right knee disorder is related to an injury in service. Alternatively, he contends his right knee disorder was caused by his service-connected left knee disorder. At the April 2019 hearing, the Veteran reported that he injured both knees in April 1976 after being thrown from a truck. He reported he was placed on light duty for a week and had continuous right knee pain “at varying degrees” since the 1976 injury. He indicated that, at times, the pain in his right knee was so severe he could not put any pressure on it, including walking. The Veteran reported that he primarily received treatment for his left knee during service because, at the time, the left knee was swollen and “seemed to be worse than the right.” However, he asserted his right knee also gave him problems during service. In an April 1976 chronological record of care, the Veteran reported hitting his left knee after falling off a truck. The attending clinician noted symptoms of swelling, effusion, and patellar pain in the left knee, but the right knee was not mentioned. The clinician prescribed crutches, Tylenol, and advised the Veteran against weight bearing with the left knee. A clinical record from the following week notes that X-rays of the left knee were normal. The Veteran continued to report left knee and left lower extremity pain, although left knee ROM and stability were noted to be normal. Several days after the incident, the Veteran was placed on a limited duty “profile.” An April 8, 1976 physical profile form indicated the Veteran had “left knee effusion.” An additional physical profile form dated April 12, 1976 indicated the Veteran had a “right knee injury.” Clinical records from later in April 1976 reflect continued treatment for traumatic arthritis and chondromalacia of the left knee, including physical therapy. While one clinical record dated April 1976 appears to contain a notation of “(R) knee injury,” the record is substantially illegible and does not further reference the right knee. The same record also noted “chondromalacia left knee,” which was documented in the majority of the other STRs throughout the Veteran’s period of active service. In a June 1976 STR, the Veteran indicated he wanted his left knee reevaluated as his previous limited duty profile was set to expire and his symptoms were increasing. He did not report right knee pain at that time. In an August 1976 record of care, the Veteran reported both knees were “acting up,” and that he had a history of knee problems. The record notes the Veteran’s knee was within normal limits upon examination and there was no evidence of a previous injury. In an April 1977 treatment record, the Veteran reported pain and swelling in his left knee after playing basketball, although he denied specific trauma. The attending clinician noted the Veteran’s history of frequent effusion and chondromalacia of the left knee but did not reference the right knee. In his May 1977 report of medical history before separation, the Veteran indicated he had “swollen or painful joints,” and “arthritis, rheumatism, or bursitis.” The report noted the Veteran had posttraumatic chondromalacia of the left knee since April 1976 with occasional swelling and mild degenerative changes noted on X-ray. The report also indicated the Veteran was evaluated and treated for his left knee condition at the U.S. Army Hospital (USAH) in Augsburg, Germany. However, the Veteran did not report a right knee condition or pain. A report of medical examination of the same date noted only “left knee chondromalacia and trace effusion with marked arthritic grinding.” A June 1977 physical profile report indicates the Veteran was again placed on limited duty due to “left knee chondromalacia.” Limitations included no crawling, stooping, running, jumping, or prolonged marching or standing. The form did not reference right knee pain, a right knee condition, or any other musculoskeletal condition. A June 1977 document entitled “Clinical Record Cover Sheet” (DA form 3647-1 “Inpatient Treatment Record Cover Sheet”) noted a diagnosis of “chondromalacia, right knee.” This document reports to have originated from an orthopedic clinic and notes the Veteran had 15 total sick days at 14 total “bed days” at the Augsburg USAH. However, records from that clinic only document treatment for left knee chondromalacia. Notably, an August 1977 “Narrative Summary” indicated the Veteran was admitted at the USAH for recurrent left knee pain and swelling since falling on his left knee in April 1976. The final diagnosis was “chondromalacia of the left patella,” and the right knee was not mentioned. The overwhelming majority of the STRs, including the separation reports of medical history and examination, document a left knee injury and diagnosis of left knee chondromalacia, but do not reference a right knee condition. These records are highly probative both as to the Veteran’s subjective reports and their resulting objective findings. They were generated with a view towards ascertaining the Veteran’s then-state of physical fitness and are akin to statements of diagnosis or treatment. Rucker v. Brown, 10 Vet. App. 67, 73 (1997) (observing that although formal rules of evidence do not apply before the Board, recourse to the Federal Rules of Evidence may be appropriate if it assists in the articulation of the reasons for the Board’s decision); see also LILLY’S: AN INTRODUCTION TO THE LAW OF EVIDENCE, 2nd Ed. (1987), pp. 245-46 (many state jurisdictions, including the federal judiciary and Federal Rule 803 (4), expand the hearsay exception for physical conditions to include statements of past physical condition on the rationale that statements made to physicians for purposes of diagnosis and treatment are exceptionally trustworthy since the declarant has a strong motive to tell the truth in order to receive proper care). Additionally, the Board finds that the references to a right knee injury in the April 1976 physical profile report and right knee chondromalacia in the June 1977 “Clinical Record Cover Sheet” are likely clerical errors. All other contemporaneous clinical (i.e. not administrative) records indicate the Veteran was treated for a left knee trauma and diagnosed with chondromalacia in the left knee only. Other than one instance in August 1976 when the Veteran reported both knees were “acting up,” the Veteran made no other documented reports of right knee issues in service. In a December 1977 VA knee examination, the Veteran reported both knees were giving him “a lot of pain.” The examiner indicated both knees were stable and the Veteran had good ROM in all joints. The Veteran reported pain in the lateral aspect of the right knee. The examiner noted a diagnosis of pain and “extreme flexion of [the] knees,” and indicated the etiology was possibly psychosomatic. X-rays taken in December 1977 did not reveal evidence of arthritis or any bone, joint, or soft tissue abnormalities in either knee. In a June 1978 VA clinic record, the Veteran reported left knee pain, “grinding,” throbbing, and that his left knee “gave out” on him at times. He did not report any right knee symptoms at that time. In an April 1990 VA treatment record, the Veteran reported pain in his left knee, right knee, and right hip. A June 1991 treatment record indicates the Veteran had no effusion in either knee and had normal ROM in his knees, back and hips. The Veteran reported feeling “weak” and having difficulty bending his knees. In an October 1991 progress note, the Veteran reported experiencing pain in both knees since 1986. An August 1992 progress note reports that the Veteran had a history of injury to his left knee but is silent as to the right knee. A June 1993 VA X-ray indicated a small effusion of the right knee with no evidence of a ligamentous or meniscal tear and noted the Veteran’s reports of patellofemoral pain in the right knee. However, X-rays taken a month later indicated that the right knee was within normal limits. At the October 1993 VA orthopedic examination, the Veteran reported his right knee began hurting in the previous five months, primarily while lifting or squatting at his job. He reported this right knee pain was like his left knee pain and that he was told by a doctor that his right knee pain was related to his left knee pain. The Veteran reported that he worked for the USPS as a custodian, and his job often involved squatting, bending his knees, and lifting heavy weights. MRI taken at the October 1993 examination revealed an abnormality of the left medial meniscus but no abnormalities in the right knee, and no change from previous MRI from 1986. On physical examination, the Veteran’s right knee demonstrated slight laxity of the anterior cruciate like that of the left knee. His gait was noted to be normal. The examiner reiterated that imaging of the right knee was essentially normal and negative for any abnormalities. The examiner concluded there was no causal relationship between the right knee and service-connected left knee disorder but did not further explain that conclusion. He noted the cause of the Veteran’s right knee pain was unknown. In an April 2011 VA treatment record, the Veteran reported left medial knee pain but did not report right knee pain. The attending clinician noted the Veteran’s gait was coordinated and smooth with no clubbing or cyanosis. The Veteran had no misalignment, defects, or deformities of the joints, bones, or muscles. The clinician indicated the Veteran had full ROM in his joints without pain. At the May 2012 VA examination, a VA indicated a diagnosis of a “right knee strain,” noting a more precise diagnosis could not be given due to a lack of objective supporting data. The Veteran reported injuring his left knee in 1975 and spending three weeks in a hospital for testing in April 1976. He stated that he was offered exploratory surgery but declined at that time. The Veteran reported his right knee pain began in 1987 while at work. He indicated his right knee pain was minor at first, but gradually worsened. He denied specific trauma to the right knee, and denied any surgeries, hospitalizations, or emergency room (E.R.) visits because of his right knee. On physical examination, no deformities were present in either knee, and the Veteran’s leg lengths were symmetrical. The 2012 VA examiner opined the Veteran’s right knee strain was not likely related to his left knee chondromalacia. The examiner noted there was no history of trauma to the right knee due to the Veteran’s left knee disorder. She further noted the Veteran did not have a leg length discrepancy causing undue stress on the right knee which could lead to the claimed right knee condition. The examiner indicated she reviewed the Veteran’s STRs, including the April 1976 physical profile report indicating a “right knee injury,” and an August 1976 treatment record where the Veteran reported both knees were “acting up.” She opined that the physical profile report was likely an error, as the medical notes referred to the left knee, not the right. The examiner further explained that chondromalacia is a condition involving degenerative changes of the kneecap bone (patella), not the femoral-tibial joint itself, and there was no credible mechanism which the Veteran’s left-sided chondromalacia could have led to his right knee strain. The examiner noted the in-service notation of both knees “acting up,” but highlighted that the Veteran’s separation examination reports were silent for a right knee condition. She indicated that, per the Veteran, there was no history of right knee complaints or treatment until the 1990s. A January 2013 VA physical therapy record notes that X-rays indicated mild osteoarthritis in the right knee. A February 2019 private orthopedic record noted a diagnosis of right knee Iliotibial band (ITB) syndrome and noted the diagnosis was possibly caused by leg length discrepancy of the right leg. At the April 2019 hearing, the Veteran reported that he first sought treatment for his right knee in 1986. He indicated that he was told by a private physician at that time that he may have subconsciously favored his left knee and shifted his weight to the right knee. He reported walking with an altered gait since 1979, which his wife and coworkers observed. The Veteran was afforded 60 days to submit additional evidence to substantiate his claim, including a medical opinion discussing his altered gait and its possible relationship to his right knee and other musculoskeletal disorders. In a May 2019 DBQ submitted by the Veteran, a private doctor noted the Veteran had painful ROM and swelling of the right knee but did not diagnose a right knee condition. The Veteran continued to report injuring his left knee, specifically, in 1976. The physician noted that imaging studies documented arthritis in the left knee, but not the right. He did not give an opinion as to the cause of the Veteran’s right knee pain, including whether it was related to the Veteran’s left knee chondromalacia, meniscus tear, or DJD. Social Security Administration (SSA) records received by VA in December 2019 reflect that the Veteran medically retired from his position at the postal service due to his bilateral knee, right hip, lower back, and right foot conditions. These records do not indicate or discuss the cause of the Veteran’s right knee or other disorders. At the January 2020 VA examination, the Veteran reported experiencing pain on the lateral side of his right knee, extending from the knee to the hip. He also reported that he could not sit with his right knee bent without pain. He reported having a right hip replacement surgery several years earlier and being told by a doctor that he may have something wrong with the lateral side of his right leg, possibly a ligament. The Veteran stated that MRI had not been helpful in diagnosing his right knee and hip issues. The 2020 VA examiner noted diagnoses of a right knee strain and ITB syndrome. She concluded the Veteran’s claimed right knee disorder was not likely caused by his left knee chondromalacia. The examiner indicated that some statistically insignificant medical studies suggest that a prolonged or pronounced gait due to an impaired lower extremity may place the contralateral weightbearing limb at risk for strain or degeneration of the joints. However, the examiner noted the Veteran’s medical records did not reflect that he developed this specific type of gait due to his left knee. After thorough review of the lay and medical evidence, the Board finds that the preponderance of the evidence is against finding service connection for a right knee disorder. The probative medical evidence indicates the Veteran’s right knee strain is not related to any in-service injury, disease or event, or to his service-connected left knee disorder. The Veteran’s service medical records document a left knee injury in 1976 that resulted in a diagnosis of chondromalacia in that knee only. As discussed above, references to a “right knee injury” and “right knee chondromalacia” in the STRs were likely made in error. As indicated above, both the May 2012 and January 2020 VA examiners offered thorough explanations as to why the Veteran’s current right knee condition was not likely caused by his left knee chondromalacia. There is no competent medical evidence that the Veteran’s right knee condition is related to an injury in service or was caused by his service-connected left knee disorder. Additionally, the evidence has not demonstrated that arthritis developed in service, was chronic during service, or manifested to a compensable degree within one year of service separation. To determine that a chronic disease was shown in service, the disease identity must be established. 38 C.F.R. § 3.303 (b); Walker v. Shinseki, 708 F.3d 1331, 1339 (Fed. Cir. 2013). While the Veteran reported right knee pain in December 1977, the VA examination report indicated that X-rays did not reveal any evidence of arthritis, soft tissue abnormalities, or any other bone or joint problem. The 1993, 2012 and 2020 VA examination reports and the 2019 DBQ submitted by the Veteran noted X-ray evidence of arthritis in the left knee, but not the right. The earliest notation of osteoarthritis in the right knee is dated January 2013, many decades after service separation. The Board has considered the Veteran’s hearing testimony that he injured both knees in 1976 and had right knee pain since that time, although his left knee condition was initially more severe. The Board has also considered the Veteran’s testimony that a private doctor speculated that the Veteran’s right knee disorder may have been caused by shifting weight onto his right leg due to his left knee disorder. The Veteran is competent to report observable symptoms, such as knee pain, and he is competent to report a contemporaneous medical diagnosis. However, as a layperson, the Veteran is not competent to diagnose himself with arthritis or determine that his right knee symptoms were manifestations of arthritis. See Jandreau, Layno, supra. Arthritis is medically complex, as it requires specialized knowledge of and interpretation of complicated diagnostic medical testing. See Jandreau, 492 F.3d at 1377 n.4. Further, the opinion purportedly expressed by the Veteran’s private doctor is speculative, unsupported by any medical rationale, and is outweighed by the January 2020 VA examiner’s opinion. For these reasons, the Veteran’s testimony is not probative as to the cause of his right knee condition. For the reasons above, service connection for a right knee disorder is denied. As the preponderance of the evidence is against the claim, the benefit-of-the-doubt doctrine is not applicable. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert, supra. 3. Service connection for a right hip disorder, including as secondary to a left knee disorder. The Veteran contends his right hip disorder is due to an altered gait caused by his service-connected left knee chondromalacia. Service treatment records (STRs) are silent for reports of hip pain or a right hip condition. In his May 1977 report of medical history at separation, the Veteran indicated he had “swollen or painful joints,” and “arthritis, rheumatism, or bursitis.” However, the report clarifies that the Veteran’s positive response related to his left knee chondromalacia with mild osteoarthritic changes. There was no mention of right hip pain or symptoms due to the left knee condition. In an October 1993 VA orthopedic examination, the Veteran reported bilateral knee pain and lower back pain but did not report right hip pain. Medical progress notes dated April 1990, June and July 1991 document reports of right hip pain and bilateral knee pain. At the April 2019 hearing, the Veteran reported he began experiencing a burning sensation in his hips in approximately 2010-2011. He reported a VA doctor later diagnosed osteoarthritis in both hips and informed him that the condition likely developed over time. VA treatment records confirm that the Veteran was diagnosed with right hip osteoarthritis and DJD in 2011. A November 2011 MRI report indicated that the Veteran’s osteoarthritis was likely related to a femoral acetabular impingement and some underlying acetabular dysplasia. A January 2012 VA PT record noted the Veteran had an antalgic gait pattern with limited weightbearing and increased frontal plane motion. The attending clinician noted the Veteran had a remote left knee injury but concluded the injury was “non-contributory” to the Veteran’s right hip pain. At the May 2012 VA hip examination, the examiner noted the Veteran did not have a history of trauma to the right hip during or after service. The examiner noted the Veteran did not have a leg length discrepancy causing undue stress on the right hip. The examiner explained that femoral acetabular impingement is commonly congenital or can be due to trauma, fracture, or surgery. The examiner noted that the Veteran’s medical history did not indicate trauma, fracture, or surgery involving the hip. Based on the absence of these factors, the examiner concluded the Veteran’s deformity was likely congenital. The VA examiner further explained that the Veteran’s congenital hip condition predisposed him to developing osteoarthritis earlier than usual. Based on these findings, the examiner opined the Veteran’s right hip disorder was less likely than not related to left knee chondromalacia. VA treatment records show continued treatment for bilateral hip pain, including hip injections and a total right hip replacement procedure in 2014. In a May 2019 knee DBQ, a private physician indicated the Veteran’s right hip replacement was a “pertinent physical finding, complication, condition, sign or symptom” related to the Veteran’s bilateral knee disorders. However, the physician did not provide any discussion or analysis of the relationship between the Veteran’s right hip and left knee disorders. In a January 2020 VA opinion, the examiner reiterated that the Veteran’s congenital deformity increased his risk of developing DJD of the hips. The examiner also noted the Veteran’s non-service-connected lower back disorder was a risk factor that contributes to development of DJD of the hips. The examiner further explained that the leg length discrepancy noted during the examination was most likely to due to the Veteran’s right hip arthroplasty. The examiner indicated that some statistically insignificant medical studies suggest that a prolonged or pronounced gait due to an impaired lower extremity may place the contralateral weightbearing limb at risk for strain or degeneration of the joints. However, the examiner noted the Veteran’s medical records did not reflect that he developed this type of gait. The preponderance of the evidence is against finding service connection for a right hip disorder secondary to a left knee disorder. The Board affords substantial probative weight to the May 2012 and January 2020 VA opinions, which were based on the Veteran’s medical history and medical literature. Both VA examiners provided a well-reasoned explanation that the Veteran’s right hip disorder developed over time because of his congenital deformity. As the probative medical evidence indicates the Veteran’s right hip disorder is not causally related to his left knee disorder, the claim is denied. In reaching its decision, the Board has considered the Veteran’s lay assertions that his left knee disorder resulted in an abnormal gait that caused his right hip disorder. While the Veteran is competent to report symptoms including an altered gait, as a layperson he is not competent to give an opinion on the etiology of a medically complex condition such as arthritis of the hip. See Jandreau, supra. The Veteran’s assertions are outweighed by the January 2020 VA examiner’s opinion that the Veteran’s gait was not the type that has been associated (albeit in statistically insignificant studies) with an increased risk of strain in the opposite limb. As the preponderance of the evidence is against the claim, the benefit-of-the-doubt doctrine is not applicable. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert, supra. 4. Service connection for a lower back disorder, including as secondary to a left knee disorder. The Veteran contends his current lower back disorder is due to an altered gait caused by his service-connected left knee chondromalacia. STRs are silent for reports of lower back symptoms or diagnosis of any lower back condition. As stated above, the Veteran’s May 1977 pre-separation physical documented left knee chondromalacia but did not reference a lower back or other musculoskeletal condition. The Veteran did not report lower back pain at the December 1977 VA examination. X-rays of the lumbosacral spine taken at that time did not reveal evidence of fracture, dislocation, bone production/destruction, and joint spaces were within normal limits. At the October 1993 VA orthopedic examination, the Veteran reported a gradual onset of low back pain in the previous two to three months. He reported his low back pain radiated down the left leg into his left foot. He indicated the pain was worsened by prolonged standing and working and relieved by lying down. On physical examination, the Veteran’s lumbar spine ROM and reflexes were normal with no muscle spasm present. The examiner indicated that imaging taken during at the examination revealed an incidental finding of four lumbar type vertebrae with sacralization of the L5 vertebra, however vertebral alignment, disc spaces and joints were normal. The examiner noted there was no evidence of fracture, dislocation, or other abnormality of the lumbar spine. The examiner diagnosed low back pain of unknown etiology and stated there was no causal relationship between the Veteran’s back pain and his left knee disorder. At the May 2012 VA examination, the Veteran alleged that his lower back had “always bothered him” since he was injured in 1975. He reported he did not have back problems prior to that injury. The Veteran indicated his low back pain was initially constant but temporarily stopped in 1976. He described a later incident where he felt a “pop” in his back while tying his boots, and that he had constant low back pain since. The VA examiner noted a diagnosis of a lumbosacral (lower back) strain with onset in service, per the Veteran’s report. However, the examiner indicated there was no history of trauma to the lower back due to a left knee disorder, or leg length discrepancy causing undue stress on the back leading to the claimed back condition. She further noted that STRs were silent for any complaints or treatment related to the back. Based on these findings, the examiner concluded there was no objective evidence of a link between the Veteran’s left knee chondromalacia and his claimed back condition. At the April 2019 hearing, the Veteran reported experiencing lower back pain and numbness in his right leg in approximately 2013 and that he sought treatment between 2015 to 2016. He reported that he was diagnosed with a bulging disc around that period. He reported he often walked “side-to-side,” to remove pressure from his left ankle, which in turn resulted in lower back pain. The Veteran indicated his lower back pain worsened with his bilateral ankle pain, although he had not discussed the relationship between his back and ankle pain with his doctors. He was afforded 60 days from the date of the hearing to submit additional evidence supporting his claims. In a January 2020 opinion, a VA examiner concluded the Veteran’s lower back disorder was not related to his service-connected left knee disorder. The examiner indicated that medical literature did not suggest a link between lumbar spine DDD and chondromalacia. She noted that risk factors for developing DDD include aging, heredity, obesity, lifestyle factors (such as work/leisure activities), and possible injury. She highlighted that the Veteran’s medical history contains several of these risk factors which would increase his likelihood of developing DDD. The preponderance of the evidence is against finding service connection for a lower back disorder secondary to a left knee disorder. The Board affords substantial probative weight to the January 2020 VA opinion, which concluded that the Veteran’s lower back disorder is more likely due to other risk factors. X-rays taken in December 1977 and October 1993 were negative for any joint or soft tissue abnormalities. As the probative medical evidence indicates the Veteran’s lower back disorder is not causally related to his left knee disorder or otherwise related to service, the claim is denied. The Board has considered the Veteran’s lay assertions that he developed lower back pain in service and that his left knee disorder contributed to his back disorder. While the Veteran is competent to report symptoms including back pain and an altered gait, as a layperson he is not competent to give an opinion on the etiology of a medically complex condition such as lumbar spine DDD. See Jandreau, supra. He is also not competent to give his own opinion as to the biomechanical effects of his left knee disorder. The Veteran’s assertions are outweighed by the January 2020 VA examiner’s opinion that the Veteran’s gait was not the type that has been associated with undue pressure on one limb, and that his DDD is more likely related to other risk factors. As the preponderance of the evidence is against the claim, the benefit-of-the-doubt doctrine is not applicable. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert, supra. 5. Service connection for a right foot disorder, including as secondary to a left knee disorder. The Veteran was diagnosed with hallux valgus (bunion) of the right foot in 2011. He contends his right foot condition was caused by his service-connected left knee disorder. A May 1973 pre-enlistment report of medical examination noted the Veteran had pes planus and that the condition was not disabling at that time. The Veteran denied “foot trouble” in a report of medical history of the same date. In his May 1977 pre-discharge report of medical examination, the Veteran’s clinical lower extremities evaluation was abnormal, however the attending physician noted left knee chondromalacia. The Veteran’s clinical feet evaluation was normal. In his pre-discharge report of medical history, the Veteran reported “swollen or painful joints” and “arthritis, rheumatism or bursitis” associated with his left knee condition, but continued to deny “foot trouble.” Other than the notation of pes planus at service entry, there are no other references to symptoms, treatment, or diagnosis related to a foot condition. At the December 1977 VA examination, the Veteran reported bilateral knee pain but did not report right foot pain. After physical examination, a VA physician indicated the Veteran’s feet were within normal limits. The Veteran continued to report knee pain at the October 1993 VA orthopedic examination but did not specifically report pain in his feet. An April 2011 VA treatment record indicates the Veteran had a normal gait that was coordinated and smooth, with no clubbing, misalignment, or joint or muscle deformities. On physical examination, his feet were noted to be normal with no deformities or calluses. In a May 2011 VA treatment record, the Veteran reported a history of bunions in his right foot and right foot pain that resulted in difficulty walking and driving. At the May 2012 VA examination, the Veteran reported having pain in his arches and bunions on both feet, primarily with weightbearing activities. He reported noticing his foot pain three years earlier, but “worked through it.” The VA examiner concluded there was no scientific basis to conclude that the Veteran’s hallux valgus could be caused or aggravated by his left knee chondromalacia. The examiner did not provide any further explanation for that opinion. A December 2015 VA radiology report notes that X-rays of the right foot revealed possible mild swelling and evidence of a prior bunionectomy. At the April 2019 hearing, the Veteran reported developing a bunion on his right foot from approximately 2009 to 2011. He reported that his right foot pain worsened at the same time his left knee condition worsened. The Veteran and his wife reported that he walked with an abnormal gait, shifting weight on his right leg to avoid putting pressure on his left leg/knee. The Veteran’s wife testified that she noticed his abnormal gait throughout the ten years she had known him. He testified that his physician informed him his bunions were related to his abnormal gait. The Veteran was afforded 60 days to submit evidence from a physician linking his foot, right knee, right hip, and back conditions with his abnormal gait. The May 2019 DBQ lists the Veteran’s right hip replacement among pertinent physical findings related to his knee conditions but does not reference any right foot disorder, pain or other symptoms related to the feet. In a January 2020 opinion, a VA clinician indicated the Veteran’s right foot disorder was not caused by his left knee chondromalacia. The examiner noted the Veteran’s right leg was shorter than the left and indicated this was most likely to due to the Veteran’s right hip arthroplasty. The examiner explained that some studies suggest that a prolonged gait due to an impaired lower extremity may place the contralateral (opposite) weightbearing limb at risk for strain or degeneration of the joints. However, she noted that these studies were statistically insignificant and, regardless, the Veteran’s medical records did not reflect that he had the type of gait referenced in the studies. The preponderance of the evidence is against finding service connection for a right foot disorder secondary to a left knee disorder. The Board affords substantial probative weight to the January 2020 VA opinion, which was based on review of the Veteran’s medical history and medical literature. As the probative medical evidence indicates the Veteran’s right foot disorder is not causally related to his left knee disorder or otherwise related to service, the claim is denied. The Board has considered the Veteran’s hearing testimony that a physician informed him that his left knee disorder caused him to put undue pressure on his right leg, causing bunions and right foot pain. However, the Veteran did not provide a medical opinion or other competent evidence to support this assertion. Without more, the opinion of his physician is speculative and is outweighed by the VA opinions indicating that his right foot and left knee disorders are not causally related. While the Veteran is competent to report observable symptoms including foot and joint pain and an altered gait, as a layperson he is not competent to give an opinion on the etiology of a medically complex condition such as hallux valgus. See Jandreau, supra. He is also not competent to give an opinion on the biomechanical effects of his left knee disorder. As the preponderance of the evidence is against the claim, the benefit-of-the-doubt doctrine is not applicable. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert, supra. REMAND The issue of a total disability evaluation based on individual unemployability, to include on an extraschedular basis, is remanded. 1. BACKGROUND FOR THE RO ADJUDICATOR: The Veteran’s service-connected left knee chondromalacia has been evaluated as 10 percent disabling since June 10, 1977. His right knee, right hip, right foot, and lower back disorders are not service-connected. Pursuant to this decision, the Veteran will be awarded an additional 10 percent rating for left knee patellar instability and a 20 percent rating for left knee effusion and “locking.” Even considering these additional ratings, the Veteran does not meet schedular criteria for a TDIU under 38 C.F.R. § 4.16 (a). Given the Board’s action and the Veteran’s assertions, the issue will be remanded for readjudication of the TDIU issue, to include referral to the office of the Director of the Compensation Service. 2. REMAND DIRECTIVES: Refer this matter to the office of the Director of Compensation Service for extraschedular consideration of TDIU. Although that office must review the file, the evidence indicates: The Veteran contends he has been unable to work since November 2011 due to his service-connected left knee disorder. The claims file reports that the Veteran has a high school education and has worked as a janitor and postal worker for the United States Postal Service (USPS). He worked at this job from 1985 until his medical retirement in November 2011 and has not worked since. He denied having any other jobs during this period. Social Security Administration (SSA) records received by VA in December 2019 reflect that the Veteran’s medical retirement was related to his bilateral knee, right hip, lower back, and right foot conditions. In a January 2011 USPS document entitled “Request for Light Duty,” a manager indicated the Veteran was unable to perform the core requirements of the Veteran’s position due to left knee and right hip conditions. At the May 2012 VA examination, the Veteran reported previous jobs including working at a kitchen in a VA hospital, a mail handler, a security officer, and an unemployment clerk. He reported that he went to school to obtain a Business Administration degree from 1979 to 1983. A 2012 SSA Disability Determination report indicated the Veteran’s residual functional capacity was limited such that he could not perform even “less than sedentary work.” The report noted the Veteran was unable to stand or walk for significantly less than two hours, and unable to sit for three hours. It also noted the Veteran was unable to perform past relevant work due to the limitations caused by his left knee and right hip. In a document entitled “Supplemental Pain Questionnaire,” the Veteran reported his left knee symptoms caused difficulty bending, lifting heavy objects, stooping, prolonged sitting, walking, and standing, and climbing stairs and ladders. January and April 2012 statements by a physician (T. Brown) indicated the Veteran had only partial capacity for light lifting and sitting for four to six hours; and no capacity for pushing/pulling, carrying, or walking/standing for two to four hours. At the April 2019 Board hearing, the Veteran testified that he is essentially unable to walk or stand for any significant period without his left knee giving out. He reported that while he was employed, he frequently missed work and had to take medical leave because of left knee pain. He indicated that sometimes his knee pain caused him to be bedridden. 3. If the benefit is not granted after extraschedular consideration or the Veteran otherwise does not qualify for the benefit, issue a Supplemental Statement of the Case, and return the matter to the Board. Vito Clementi Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board B. Hiaasen 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.