Citation Nr: 21063264 Decision Date: 10/13/21 Archive Date: 10/13/21 DOCKET NO. 16-42 345 DATE: October 13, 2021 ORDER Entitlement to an initial disability rating of 20 percent for left lower extremity radiculopathy is granted on and after February 1, 2011, subject to the laws and regulations governing the payment of monetary benefits. Entitlement to an initial disability rating of 10 percent for right lower extremity radiculopathy is granted on and after February 1, 2011, subject to the laws and regulations governing the payment of monetary benefits. Entitlement to a disability rating of 10 percent, but no more, for left knee osteoarthritis is granted on and after February 1, 2011, subject to the laws and regulations governing the payment of monetary benefits. Entitlement to a separate disability rating of 10 percent, but no more, for left knee instability is granted on and after February 1, 2011, subject to the laws and regulations governing the payment of monetary benefits. Service connection for a right ankle disability is granted. Service connection for right carpal tunnel syndrome (CTS) is granted. Service connection for left CTS is granted. Service connection for chronic fatigue syndrome (CFS) is denied. REMANDED Entitlement to an initial disability rating in excess of 20 percent for left lower extremity radiculopathy is remanded. Entitlement to an initial disability rating in excess of 10 percent for right lower extremity radiculopathy is remanded. Entitlement to disability ratings in excess of 10 percent from February 1, 2011 to December 1, 2019, and in excess of 20 percent on and after December 2, 2019, for degenerative joint disease of the lumbar spine is remanded. Service connection for a hernia, including an inguinal hernia, a hiatal hernia, a diaphragmatic hernia, and diastasis recti is remanded. FINDINGS OF FACT 1. On and after February 1, 2011, the Veteran's left lower extremity radiculopathy manifests as moderate incomplete paralysis of the common peroneal nerve. 2. On and after February 1, 2011, the Veteran's right lower extremity radiculopathy manifests as mild incomplete paralysis of the common peroneal nerve. 3. For the period on appeal, the Veteran's left knee osteoarthritis was manifested as painful motion and slight lateral instability, but not ankylosis, limitation of flexion to 45 degrees, limitation of extension to 10 degrees, recurrent subluxation, dislocated or removed semilunar cartilage, or impairment of the tibia or fibula. 4. Clear and unmistakable evidence demonstrates that the Veteran's right ankle disability existed prior to his January 2010 to January 2011 period of active duty service but does not demonstrate that it was not aggravated by such service. 5. The probative evidence of record is at least in equipoise as to whether the Veteran's right ankle disability is etiologically related to his active duty service. 6. The probative evidence of record is at least in equipoise as to whether the Veteran's right CTS is etiologically related to his active duty service. 7. The probative evidence of record is at least in equipoise as to whether the Veteran's left CTS is etiologically related to his active duty service. 8. The preponderance of the evidence is against finding that the Veteran has CFS. CONCLUSIONS OF LAW 1. With resolution of reasonable doubt in the Veteran's favor, on and after February 1, 2011, the criteria for a rating of 20 percent for left lower extremity radiculopathy have been met. 38 U.S.C. §§ 1155, 5107 (2012); 38 C.F.R. §§ 3.102, 4.1-4.14, 4.21, 4.124a, Diagnostic Code 8721 (2021). 2. With resolution of reasonable doubt in the Veteran's favor, on and after February 1, 2011, the criteria for a rating of 10 percent for right lower extremity radiculopathy have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 4.1-4.14, 4.21, 4.124a, Diagnostic Code 8721. 3. With resolution of reasonable doubt in the Veteran's favor, on and after February 1, 2011, the criteria for a rating of 10 percent, but no higher, for left knee osteoarthritis have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 4.1-4.14, 4.21, 4.40, 4.45, 4.59, 4.71a, Diagnostic Codes 5010-5260 (2021). 4. With resolution of reasonable doubt in the Veteran's favor, on and after February 1, 2011, the criteria for a separate rating of 10 percent, but no higher, for left knee instability have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 4.1-4.14, 4.21, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257 (2021). 5. With resolution of reasonable doubt in the Veteran's favor, the criteria for a grant of service connection for a right ankle disability have been met. 38 U.S.C. §§ 1110, 1111, 5107 (2012); 38 C.F.R. §§ 3.102, 3.303, 3.304 (2021). 6. With resolution of reasonable doubt in the Veteran's favor, the criteria for a grant of service connection for right CTS have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304. 7. With resolution of reasonable doubt in the Veteran's favor, the criteria for a grant of service connection for left CTS have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304. 8. The criteria for establishing service connection for unexplained CFS have not been met. 38 U.S.C. §§ 1110, 5107 (2012); 38 C.F.R. §§ 3.102, 3.303, 3.304, 4.88a (2021). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the Army from March 2003 to September 2003, from April 2005 to August 2006, and from January 2010 to January 2011, including service in Afghanistan, with additional service in the Army National Guard. These matters are on appeal from an August 2012 rating decision. In a February 2019 decision, the Board remanded the issues being decided below to attempt to obtain additional records and to afford the Veteran additional VA examinations and medical opinions. The Agency of Original Jurisdiction (AOJ) has done so. The Veteran was afforded VA examinations for the issues being decided below in December 2019. Although the Board finds that the December 2019 VA medical opinions with regard to the Veteran's right ankle disability and right and left carpal tunnel were inadequate, because the Board is granting those claims in full, any errors in compliance with remand directives with regard to those claims are harmless. See Stegall v. West, 11 Vet. App. 268 (1998). The VA examinations are adequate with regard to the Veteran's left knee, low back, and chronic fatigue claims because they were based upon consideration of the Veteran's pertinent medical history, his lay assertions and current complaints, and because they describe his left knee, low back, and fatigue symptoms in detail sufficient to allow the Board to make fully informed determinations. Barr v. Nicholson, 21 Vet. App. 303 (2007) (citing Ardison v. Brown, 6 Vet. App. 405, 407 (1994)). There was therefore substantial compliance with the remand directives with regard to the issues being decided below. See Stegall, 11 Vet. App. 268. The Board will discuss the compliance of the December 2019 VA examiner with regard to the hernia claim below. The Board also remanded claims for service connection for pain in all joints and muscles and bilateral hearing loss. In a July 2020 rating decision, the AOJ granted service connection for bilateral hearing loss. In a February 2021 rating decision, the AOJ granted service connection for psoriatic arthritis (claimed as bone pains and pains in all joints and muscles). These issues are no longer before the Board. The Veteran's service treatment records are incomplete. For example, in an August 2012 formal finding, VA determined that service treatment records for his period of active duty service from March 2003 to September 2003 were unavailable. The AOJ has documented its efforts to locate the complete records. In cases where records once in the hands of the government are lost, the Board has a heightened obligation to explain its findings and conclusions and to consider carefully the benefit-of-the-doubt rule where applicable. See O'Hare v. Derwinski, 1 Vet. App. 365, 367 (1991). Because of the missing records, the analysis below has been undertaken with this heightened duty in mind. The case law does not, however, lower the legal standard for proving a claim for service connection but rather increases the Board's obligation to evaluate and discuss in its decision all of the evidence that may be favorable to the Veteran. See Russo v. Brown, 9 Vet. App. 46 (1996). VA is free to bifurcate a claim and adjudicate it in separate pieces. Tyrues v. Shinseki, 23 Vet. App. 166, 186 (2009) (en banc), aff'd, 631 F.3d 1380 (Fed. Cir. 2011); rev'd on other grounds, 132 S.Ct. 75 (2011). Further, "[b]ifurcation of a claim generally is within the Secretary's discretion." Locklear v. Shinseki, 24 Vet. App. 311, 315 (2011). In this decision, the Board is granting initial 20 and 10 percent ratings for radiculopathy of the left and right lower extremities, respectively. However, the Board will remand the issues of whether the Veteran is entitled to initial ratings in excess of 20 and 10 percent for the left and right lower extremities, respectively, because additional development is needed. By bifurcating this issue, the Veteran will receive the award resulting from this grant earlier than if the entire issue were remanded. This outcome is more favorable to the Veteran. In his July 2013 Notice of Disagreement (NOD), the Veteran contended that the June 2011 VA examiner did not use a goniometer when examining his leg to evaluate the range of motion of his left knee and did not perform a McMurray test. In order to afford the Veteran the benefit of the doubt, the Board will assume that these contentions are accurate and the June 2011 VA examiner's findings with regard to the range of motion of his left knee will play no role in the Board's analysis. Neither the Veteran nor his representative have raised any other issues with the duty to notify or duty to assist with regard to the issues being decided below. See Scott v. McDonald, 789 F.3d 1375, 1381 (Fed. Cir. 2015) (holding that "the Board's obligation to read filings in a liberal manner does not require the Board... to search the record and address procedural arguments when the veteran fails to raise them before the Board."); Dickens v. McDonald, 814 F.3d 1359, 1361 (Fed. Cir. 2016) (applying Scott to a duty to assist argument). Increased Ratings Disability ratings are determined by applying a schedule of ratings that is based on average impairment of earning capacity. Separate Diagnostic Codes identify the various disabilities. 38 U.S.C. § 1155; 38 C.F.R. Part 4 (2021). Each disability must be viewed in relation to its history and the limitation of activity imposed by the disabling condition should be emphasized. 38 C.F.R. § 4.1. "Staged" ratings are appropriate for an increased rating claim when the factual findings show distinct time periods where the service-connected disability exhibits symptoms that would warrant different ratings. Hart v. Mansfield, 21 Vet. App. 505 (2007). Given the nature of the present claims for higher initial evaluations, the Board has considered all evidence of severity since the effective dates for the awards of service connection. Fenderson v. West, 12 Vet. App. 119 (1999). Where there is a question as to which of two disability evaluations shall be applied, the higher evaluation is to be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating is to be assigned. 38 C.F.R. § 4.7. In determining the appropriate rating for musculoskeletal disabilities, particular attention is focused on functional loss of use of the affected part. Factors of joint disability include increased or limited motion, weakened movement, excess fatigability, incoordination, and painful movement, including during flare-ups and after repeated use. DeLuca v. Brown, 8 Vet. App. 202, 206-08 (1995); 38 C.F.R. § 4.45. A finding of functional loss due to pain must be supported by adequate pathology and evidenced by the visible behavior of the claimant. 38 C.F.R. § 4.40. Additionally, "pain itself does not rise to the level of functional loss as contemplated by the VA regulations applicable to the musculoskeletal system." Mitchell v. Shinseki, 25 Vet. App. 32, 38 (2011). Pain in a particular joint may result in functional loss, but only if it limits the ability to perform the normal working movements of the body with normal excursion, strength, speed, coordination, or endurance. Id.; 38 C.F.R. § 4.40. Under 38 C.F.R. § 4.59, painful joints are entitled to at least the minimum compensable rating for the joint. Nonetheless, even when the background factors listed in § 4.40 or 4.45 are relevant when evaluating a disability, the rating is assigned based on the extent to which motion is limited, pursuant to 38 C.F.R. § 4.71a; a separate or higher rating under § 4.40 or 4.45 itself is not appropriate. See Thompson v. McDonald, 815 F.3d 781, 785 (Fed. Cir. 2016) ("[I]t is clear that the guidance of § 4.40 is intended to be used in understanding the nature of the veteran's disability, after which a rating is determined based on the § 4.71a criteria."). During the pendency of the appeal, the rating criteria for evaluating musculoskeletal disabilities under 38 C.F.R. § 4.71a were amended effective February 7, 2021. 85 Fed. Reg. 230 (Nov. 30, 2020). These amendments revised select diagnostic codes "to ensure that this portion of the rating schedule uses current medical terminology and provides detailed and updated criteria for the evaluation of musculoskeletal disabilities." Id. If a law or regulation changes during the course of a claim or an appeal, the version more favorable to the Veteran will apply, to the extent permitted by any stated effective date in the amendment in question. 38 U.S.C. § 5110(g). If the revised version of the regulation is more favorable, the implementation of that regulation under 38 U.S.C. § 5110(g) can be no earlier than the effective date of that change. If the former version is more favorable, VA can apply the earlier version of the regulation for the period prior to, and from, the effective date of the change. 38 U.S.C. § 5110. Therefore, the Board will consider the Veteran's claims under the old criteria prior to February 7, 2021 and both the old and new rating criteria from February 7, 2021. The criteria that are more favorable to the Veteran will be applied. 1. Left Lower Extremity Radiculopathy 2. Right Lower Extremity Radiculopathy As a result of a July 2013 claim submitted while this appeal was pending, VA has separately granted service connection for the Veteran's radiculopathy of the left and right lower extremity. It is currently rated under 38 C.F.R. § 4.124a, Diagnostic Code 8721, for neuralgia of the common peroneal nerve, with a 20 percent rating in the left lower extremity and a 10 percent rating in the right lower extremity on and after July 17, 2013, the date of the claim. Because the General Formula specifies that any associated objective neurologic abnormalities caused by the Veteran's low back disability are to be evaluated separately under an appropriate Diagnostic Code, the Board finds that it must consider the Veteran's radiculopathy for the same period as was under consideration for the lumbar spine disability, i.e., the period on and after February 1, 2011. See 38 C.F.R. § 4.71a at Note (1); Chavis v. McDonough, 34 Vet. App. 1 (2021). 38 C.F.R. § 4.124a, Diagnostic Code 8721 pertains to neuralgia of the external popliteal (common peroneal) nerve. The maximum rating for neuralgia is equal to that for moderate incomplete paralysis. 38 C.F.R. § 4.124 (2021). Under 38 C.F.R. § 4.124a, Diagnostic Code 8521 (2021), paralysis of the common peroneal nerve is rated as follows: complete paralysis (40 percent); severe incomplete paralysis (30 percent); moderate incomplete paralysis (20 percent); and mild incomplete paralysis (10 percent). When the involvement is wholly sensory, the rating should be for the mild or, at most, the moderate degree. See note at "Diseases of the Peripheral Nerves" in 38 C.F.R. § 4.124(a). The Veteran was afforded a VA examination for spine conditions in June 2011. Although the Veteran reported sharp radiating pain into his right hip and buttock, reflexes and sensory and motor examinations were normal. In his March 2013 NOD, the Veteran stated that he reported bilateral leg pain to the examiner. The Veteran was afforded a VA examination for peripheral nerves conditions in June 2014. The clinician diagnosed radiculopathy and noted that it had been initially diagnosed in December 2012. Based on the evidence described above, the Board finds that, affording the Veteran the benefit of the doubt, his bilateral lower extremity radiculopathy was present and warrants a rating of 20 percent for the left lower extremity and 10 percent for the right lower extremity on and after February 1, 2011. Although the June 2011 examiner did not diagnose radiculopathy, the record contains evidence of a diagnosis in December 2012 and the Veteran has stated that he reported bilateral leg pain at the time of the June 2011 VA examination. The Board therefore finds that it is at least as likely as not that the Veteran's low back disability was manifested by left lower extremity radiculopathy of moderate severity and right lower extremity radiculopathy of mild severity throughout the period on appeal. However, as stated above, the Board remands the issues of entitlement to ratings in excess of 20 percent for left lower extremity radiculopathy and 10 percent for right lower extremity radiculopathy because further development is required. 3. Left Knee Osteoarthritis 4. Left Knee Instability The Veteran contends that his left knee disability warrants higher ratings than those currently assigned. It is currently rated under 38 C.F.R. § 4.71a, Diagnostic Codes 5010-5260, with a noncompensable rating from February 1, 2011 to June 12, 2014 and a 10 percent rating on and after June 13, 2014. Hyphenated diagnostic codes are used when a rating under one Diagnostic Code requires use of an additional Diagnostic Code to identify the basis for the evaluation assigned; the additional code is shown after the hyphen. 38 C.F.R. § 4.27 (2021). Diagnostic Code 5010 pertains to traumatic arthritis and Diagnostic Code 5260 pertains to limitation of leg flexion. The full period of service connection is on appeal. Prior to the amendment, Diagnostic Code 5010 provided for rating as degenerative arthritis under Diagnostic Code 5003. Diagnostic Code 5003 provides, when limitation of motion is noncompensable under the appropriate Diagnostic Code, for a 10 percent rating for each major joint or group of minor joints affected by limitation of motion. 38 C.F.R. § 4.71a, Diagnostic Code 5003. Limitation of motion must be objectively confirmed by findings such as swelling, muscle spasm, or satisfactory evidence of painful motion. Id. For rating purposes, the knee is considered a major joint. 38 C.F.R. § 4.45. As the Veteran is already receiving a 10 percent rating based on painful motion on and after June 13, 2014 and the Board is granting a 10 percent rating on the same basis for the remainder of the period on appeal, an increased rating under Diagnostic Code 5003 is not applicable. Further discussion of Diagnostic Code 5010 under the prior criteria is therefore not warranted. After the amendment, Diagnostic Code 5010 provides for rating as limitation of motion, dislocation, or other specified instability under the affected joint. Schedule for Rating Disabilities: Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76463 (Nov. 30, 2020) (to be codified at 38 C.F.R. § 4.71a, Diagnostic Code 5010). Limitation of flexion of the leg is evaluated as follows: flexion limited to 15 degrees (30 percent); flexion limited to 30 degrees (20 percent); flexion limited to 45 degrees (10 percent); and flexion limited to 60 degrees (noncompensable). 38 C.F.R. § 4.71a, Diagnostic Code 5260. Limitation of extension of the leg is evaluated as follows: extension limited to 45 degrees (50 percent); extension limited to 30 degrees (40 percent); extension limited to 20 degrees (30 percent); extension limited to 15 degrees (20 percent); extension limited to 10 degrees (10 percent); and extension limited to 5 degrees (noncompensable). 38 C.F.R. § 4.71a, Diagnostic Code 5261. For VA purposes, a normal range of knee motion is from 0 degrees of extension to 140 degrees of flexion. 38 C.F.R. § 4.71, Plate II. There are additional Diagnostic Codes that apply to knee disorders. 38 C.F.R. § 4.71a, Diagnostic Code 5256 (2021) pertains to ankylosis of the knee. Prior to the amendment, recurrent subluxation or lateral instability of the knee was evaluated as follows: severe (30 percent); moderate (20 percent); and slight (10 percent). 38 C.F.R. § 4.71a, Diagnostic Code 5257. After the amendment, a compensable rating for knee subluxation requires that subluxation be the result of a ligament tear and a compensable rating for patellar instability requires that instability be a diagnosed condition. Schedule for Rating Disabilities: Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76463 (Nov. 30, 2020) (to be codified at 38 C.F.R. § 4.71a, Diagnostic Code 5257). Because the record contains no evidence of a ligament tear or diagnosed patellar instability, these criteria are less favorable to the Veteran and the old criteria will be used throughout the period on appeal. Meniscal conditions are evaluated as follows: dislocated semilunar cartilage with frequent episodes of "locking," pain, and effusion into the joint (20 percent); and symptomatic removal of semilunar cartilage (10 percent). 38 C.F.R. § 4.71a, Diagnostic Codes 5258 and 5259 (2021). Prior to the amendment, impairment of the tibia and fibula were evaluated as follows: nonunion with loose motion, requiring a brace (40 percent); malunion with marked knee or ankle disability (30 percent); malunion with moderate knee or ankle disability (20 percent); and malunion with slight knee or ankle disability (10 percent). 38 C.F.R. § 4.71a, Diagnostic Code 5262 (2021). After the amendment, impairment of the tibia and fibula are evaluated as follows: nonunion with loose motion, requiring a brace (40 percent); malunion (evaluate under whichever of Diagnostic Codes 5256, 5257, 5260, or 5261 results in the highest evaluation); or medial tibial stress syndrome (MTSS) or shin splints (rate between 0 and 30 percent depending on the length and efficacy of treatment). Schedule for Rating Disabilities: Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76463 (Nov. 30, 2020) (to be codified at 38 C.F.R. § 4.71a, Diagnostic Code 5262). The Veteran was afforded a VA examination for joint conditions in June 2011. The Veteran reported pain in his legs with stiffness and soreness. With regard to his knees, he reported pain and stiffness, but no deformity, giving way, instability, weakness, incoordination, decreased speed of joint motion, episodes of subluxation or dislocation, locking episodes, effusions, or symptoms of inflammation. He did not report that the motion of the joint was affected and he did not report any flare ups. The Veteran did not report limitations to standing or walking and did not report using any assistive devices. On examination, there was no crepitation, grinding, instability, or patellar or meniscal abnormality. The examiner found a normal range of motion but, as stated above, in order to give the Veteran the benefit of the doubt with regard to his contention that the clinician did not use a goniometer, the Board will not consider this finding. The clinician diagnosed osteoarthritis of both knees. A November 2012 VA x-ray found degenerative joint disease that the radiologist interpreted as very mild. During a May 2013 VA treatment appointment, the Veteran reported increased knee pain after a racquetball injury, with no locking but occasional effusion and some stiffness in the morning. The treatment provider diagnosed left knee arthralgia. A July 2013 VA treatment record notes that a recent left knee MRI showed an incidental discoid lateral meniscus but no tear, with some chondral fissuring but no ligament tear. He was issued a knee brace that the treatment provider noted was "medically necessary for prevention of edema, pain, instability." In his July 2013 NOD, the Veteran reported pain and instability in his left knee and that he had reported this to the June 2011 VA examiner. He also reported having recently received a knee brace due to instability and pain. The Veteran was afforded an additional VA examination for joint conditions in June 2014. With regard to his knees, he reported giving way, pain, stiffness, decreased speed of motion, and crepitus, but not deformity, instability, weakness, incoordination, episodes of dislocation or subluxation, or effusions. He reported that the motion of the joint was affected but did not report any flare ups. He reported being able to stand for up to one hour and walk from one to three miles. He reported intermittently but frequently using a left knee brace. On examination, there was crepitus, edema, heat, redness, tenderness, and pain at rest, but no grinding, instability, patellar or meniscal abnormality, locking, or effusion. Range of motion was reported as 0 degrees of extension to 140 degrees of flexion, with objective evidence of pain with active motion. There were no additional limitations upon repetition. An x-ray on the day of the examination showed mild degenerative changes of the knees, unchanged since the November 2012 x-ray. The Veteran was afforded a VA examination for knee and lower leg conditions in May 2016. The clinician diagnosed degenerative arthritis. The Veteran reported that his left knee symptoms had worsened and his pain was now constant, but he did not report flare ups. He reported functional impairment in the form of difficulty walking. On examination, range of motion was reported as normal, but the clinician also noted that there was pain on flexion and extension and it caused functional loss. The clinician also expressed inability to opine as to whether there would be significant limits to functional ability with repetition over time without "objective evidence" instead of the Veteran's lay reports. For these reasons, the clinician's findings with regard to range of motion are inadequate and of no probative value; they will play no role in the Board's analysis. Knee strength was normal, with no muscle atrophy, and there was no ankylosis. The clinician noted no history of recurrent subluxation, instability, or effusion. Joint stability testing was normal. There was no tibial or fibular impairment. The clinician noted no history of meniscal conditions. The Veteran did not report using any assistive devices. The clinician found that the Veteran's left knee symptoms would have a mild impact on his ability to work due to chronic pain while walking. The clinician noted that a 2016 x-ray found mild degenerative changes with a stable appearance since the last examination. The Veteran was afforded an additional VA examination for knee and lower leg conditions in December 2019. The clinician diagnosed degenerative arthritis. The Veteran reported worsening symptoms over the years, including feeling unstable and having difficulty bending. He did not report flare ups or functional impairment. On examination, range of motion was reported as 0 degrees of extension to 115 degrees of flexion. The range of motion contributed to functional loss by causing difficulty bending, walking, and standing for long periods. There was no pain on examination, including evidence of pain with weight bearing and objective evidence of localized tenderness or pain on palpation. There was no objective evidence of crepitus. There was no additional loss of motion on repetition. The clinician indicated that the examination was not immediately after repetitive use over time but that these circumstances would not significantly limit functional ability, based on review of the medical records and lay statements. There were no additional factors contributing to disability. There was no muscle atrophy or reduction in muscle strength. There was no ankylosis and the clinician noted no history of recurrent subluxation, instability, or effusion. Joint stability testing was normal. There was no tibial or fibular impairment and the clinician noted no history of a meniscal condition. The Veteran did not report using any assistive devices. The clinician found that the Veteran's knee disabilities would have an impact on his ability to work because he would have difficulty bending, walking, and standing for long periods. The clinician noted that the Veteran had lost less than one week of work in the past 12 months due to his knee symptoms. The clinician added that there was no objective evidence of pain on passive range of motion testing or non-weight bearing. Based on the evidence described above, the Board finds that, affording the Veteran the benefit of the doubt, his left knee instability warrants a separate 10 percent rating throughout the period on appeal. The Veteran has reported instability on multiple occasions, but no examiner or treatment provider has found subluxation and stability testing during the period on appeal has found no instability. Under the prior criteria, Diagnostic Code 5257 did not require objective medical evidence of subluxation or lateral instability for a rating to be assigned. See English v. Wilkie, 30 Vet. App. 347 (2018). Because the Veteran has competently and credibly reported left knee instability, the Board finds that a separate 10 percent rating is warranted for slight instability of the knee. The Veteran's knee instability is not more accurately described as moderate. The medical records do not describe instability of the knee joint and VA examiners have repeatedly found that the knee joint is normal on all stability tests. The Board finds that knee instability that causes functional impairment but is undetectable on all forms of examination is best characterized as slight. Additionally, the VA examiners have consistently found that there was no history of lateral instability or recurrent subluxation. In addition, based on the evidence described above, the Board finds that, affording the Veteran the benefit of the doubt, his left knee osteoarthritis warrants a 10 percent rating throughout the period on appeal. The Veteran has consistently reported painful motion. As stated above, under 38 C.F.R. § 4.59, painful joints are entitled to at least the minimum compensable rating for the joint. The preponderance of the evidence described above also shows that the Veteran's left knee osteoarthritis does not warrant a rating in excess of 10 percent under Diagnostic Code 5260. A 20 percent rating under Diagnostic Code 5260 requires limitation to 30 degrees. No examiner or treatment provider has found that the Veteran's left leg flexion has been limited to less than 115 degrees during this period, including with the effects of repetition over time, and the Veteran has consistently denied flare ups. The preponderance of the evidence described above also shows that the Veteran's left knee osteoarthritis does not warrant a separate rating under Diagnostic Code 5261. The Veteran is already compensated for painful movement of his left knee joint in his rating under Diagnostic Code 5260. A 10 percent rating under Diagnostic Code 5261 requires limitation to 10 degrees. No examiner or treatment provider has found that the Veteran's left leg extension has been limited during this period, including with the effects of repetition over time, and the Veteran has consistently denied flare ups. The preponderance of the evidence also shows that the Veteran's knee disabilities were not manifested by ankylosis or impairment of the tibia or fibula during this period. Although a 2013 MRI noted a discoid lateral meniscus, there was no tear and the record contains no evidence of dislocated or removed meniscal cartilage. The Board has considered the Veteran's lay statements. The Veteran is competent to report his own observations with regard to the symptoms of his knee disability and his descriptions are credible. See Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). The Board has accepted those statements as the basis for granting a separate 10 percent rating for instability of the left knee and an earlier effective date for the 10 percent rating for painful motion of the left knee. However, nothing in the Veteran's lay statements provides a basis for assigning higher ratings than those assigned herein under any Diagnostic Code pertaining to musculoskeletal disabilities of the knee. In addition, the Board considered whether higher ratings are warranted under the regulations relating to additional functional loss due to pain, weakness, fatigability, incoordination, and other factors under DeLuca, 8 Vet. App. at 204-07; 38 C.F.R. §§ 4.40, 4.45. The Veteran's representative, in an August 2021 statement, requested an increased rating based on pain. However, there is nothing to indicate that the Veteran's pain or any other DeLuca factor causes functional impairment equivalent to the criteria for ratings in excess of those already in effect or assigned herein. Because the Board considered the applicable ratings under every Diagnostic Code pertaining to musculoskeletal disabilities of the knee, the Board finds that there are no other potentially applicable Diagnostic Codes by which higher ratings can be assigned. Service Connection Service connection may be established for a disability resulting from disease or injury incurred in or aggravated by service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303. Regulations also provide that service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disability was incurred in service. 38 C.F.R. § 3.303(d). Generally, in order to prove service connection, there must be competent, credible evidence of (1) a current disability, (2) in-service incurrence or aggravation of an injury or disease, and (3) a nexus, or link, between the current disability and the in-service disease or injury. Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). 5. Right Ankle Disability The Veteran contends that he has a right ankle disability that is etiologically related to his active duty service. Every veteran is presumed to have been in sound condition at entry into service except as to defects, infirmities, or disabilities noted at the time of such entry, or where clear and unmistakable evidence demonstrates that the injury or disease existed before entry and was not aggravated by such service. 38 U.S.C. § 1111. Only such conditions as are recorded in examination reports are to be considered as "noted." 38 C.F.R. § 3.304. A history of preservice existence of conditions recorded at the time of examination does not constitute a notation of such conditions but will be considered together with all other material evidence in determinations as to inception. 38 C.F.R. § 3.304(b)(1). The record does not contain entrance examinations for any of the Veteran's three periods of active duty service. Therefore, the presumption of soundness attaches with respect to this issue. To rebut the presumption of soundness the burden is on VA to satisfy a two-prong test by showing by clear and unmistakable evidence that the Veteran's disability both existed prior to service and was not aggravated during service. See Wagner v. Principi, 370 F.3d 1089, 1096 (Fed. Cir. 2004); Bagby v. Derwinski, 1 Vet. App. 225, 227 (1991). Even when there is clear and unmistakable evidence of preexistence, the claimant need not produce any evidence of aggravation in order to prevail under the aggravation prong of the presumption of soundness. Rather, the burden is on VA to establish by clear and unmistakable evidence that it did not or that any increase was due to the natural progress of the disease. Horn v. Shinseki, 25 Vet. App. 231, 235 (2012). A service treatment record from August 2005, which was during one of the Veteran's periods of active duty service (specifically, during his deployment to Afghanistan), notes the Veteran's report of twisting his ankle on his way from the chow hall to work. In a July 2006 report of medical assessment, the Veteran reported that his right ankle "sprains easily." During a January 2007 VA treatment appointment, the Veteran reported continued right ankle pain and a popping sensation while running, with increased pain and swelling in cold conditions or rain. VA treatment records from December 2008 note the Veteran's report of a right ankle injury while playing racquetball, resulting in a diagnosis of a ruptured right Achilles tendon. This rupture was surgically repaired later in December 2008; the operative report characterized the rupture as acute. VA treatment records from March 2011, a month and a half after the Veteran's final separation from active duty service, note his report of localized tenderness at the site of the 2008 surgery without any recent trauma. This resulted in a diagnosis of another partial rupture of the right Achilles tendon. An MRI at the time noted findings of a partial intrasubstance tear of the Achilles tendon superimposed on postsurgical changes and chronic tendinosis and likely sequelae of old trauma involving the ankle joint ligaments. This tear was surgically repaired in April 2011. The Veteran was afforded a VA examination for joint conditions in June 2011, four months after his final separation from active duty service. The Veteran reported that his right ankle pain had its onset after the 2005 injury and that he was treated at the time for a sprain but the pain continued afterward when running, eventually resulting in a diagnosis of a ruptured Achilles tendon. An x-ray on the day of the examination showed chronic Achilles tendinopathy versus tendinitis involving the right Achilles tendon and bilateral posterior calcaneal spurs. The clinician diagnosed chronic Achilles tendonitis and calcaneal spurs but did not opine as to the etiology of either condition. In his March 2013 NOD, the Veteran reported continued ankle symptoms of his 2005 injury and contended that it was "continuously aggravated" by physical exercise during his January 2010-January 2011 period of active duty service. He also included a photograph of his ankle and reported that it showed his condition at the time of the 2005 injury. The Veteran was afforded an additional VA examination for joint conditions in June 2014. The clinician generally diagnosed degenerative arthritis and hypocalcemia of unspecified joints and did not opine as to its etiology. A June 2013 VA treatment record notes the opinion of the Veteran's treating primary care physician that "it is at least as likely as not or at least probable" that his current right ankle disability stemmed from the 2005 sprain, which led to the 2008 and 2011 ruptures, because the 2005 injury was incurred during active duty service and then the ankle symptoms were aggravated by later service. The Veteran was afforded a VA examination for ankle conditions in May 2016. The clinician diagnosed right Achilles tendinitis, status post Achilles tendon rupture surgery, and a calcaneal spur. The clinician opined that it was less likely than not that the tendon ruptures were caused by the 2005 injury because there was no mention of Achilles tendon symptoms in the service treatment records and "the weight of the medical literature is against a relationship between inversion ankle injury mechanism" and Achilles tendon rupture. The clinician did not opine with regard to the contention that the 2008 rupture was aggravated by the 2010-2011 period of active duty service. The Veteran was afforded an additional VA examination for ankle conditions in December 2019. The clinician opined that the Veteran's right ankle disability clearly and unmistakably existed prior to his 2010-2011 period of active duty service. With regard to this question, the Board finds that the clinician's opinion is adequate. However, with regard to the question of aggravation, the clinician opined that the Veteran's right ankle disability was clearly and unmistakably not aggravated beyond its natural progression by that service because, although "[t]emporary aggravation is plausible," "there is no evidence of permanent aggravation." The clinician's opinion did not address the Veteran's report of aggravation, the need for additional surgery two months after separation, or the June 2011 diagnosis of a chronic disability that had been characterized as acute in 2008. For these reasons, the clinician's opinion with regard to aggravation is inadequate. The only clinician to opine as to whether the Veteran's right ankle disability clearly and unmistakably existed prior to his 2010-2011 period of active military service opined that it did. The Board has, however, found that clinician's opinion inadequate with regard to the question of aggravation. Although the VA primary care physician did not provide an opinion that explicitly addressed the question of whether the Veteran's right ankle disability was clearly and unmistakably not aggravated by active duty service, by finding that it was aggravated, the physician necessarily found that it was not clearly and unmistakably not aggravated. The physician did not provide a thorough rationale for this opinion, but the record also contains evidence that the Veteran's right ankle required surgery shortly after his separation from active duty service and that the diagnosed right ankle disability was acute prior to that period of service and chronic after it. The Board therefore does not find that there is clear and unmistakable evidence that the Veteran's right ankle disability was not aggravated by his 2010-2011 period of active duty service. The presumption of soundness is not rebutted. The Board must therefore turn to the question of service connection, proceeding on the presumption that the Veteran was sound at the time of his January 2010 entry into his final period of active duty service. Of the medical opinions of record, the only ones to address this question with regard to the 2010-2011 period of active duty service are those of the December 2019 VA examiner and the VA primary care physician. As stated above, the Board has found the December 2019 opinion inadequate; the primary care physician's opinion, which is favorable to the Veteran's claim, is therefore the most probative opinion of record. After resolving all reasonable doubt in his favor, the evidence of record supports a finding that it is at least as likely as not that the Veteran's right ankle disability is etiologically related to his active duty service. Accordingly, the Board finds that granting service connection for a right ankle disability is the decision that is the most consistent with VA's policy to administer the law under a broad and liberal interpretation consistent with the facts of the case. 38 C.F.R. § 3.303(a). 6. Right CTS 7. Left CTS The Veteran contends that he has bilateral CTS that is etiologically related to his active duty service. During a March 2008 VA treatment appointment, the Veteran reported a 3-4 month history of numbness and tingling in both hands. The treatment provider diagnosed CTS but clarified that the Veteran "appears to have acute CTS with no apparent atrophy or thenars or sensory deficits at this time." The Veteran was afforded a VA examination in June 2011. The clinician noted that the Veteran reported that his CTS had its onset in approximately 2006 during firefighter training and was told at the time that he had overuse syndrome, then had nerve conduction testing done at a VA facility, which confirmed CTS. The clinician diagnosed bilateral CTS of unknown etiology but added that it was "without residual," so this likely refers to a past diagnosis instead of a current one. VA has attempted without success to obtain a copy of this nerve conduction study. A July 2013 VA treatment record notes the opinion of the Veteran's treating VA primary care physician, who noted that the Veteran had reported numbness and tingling in his hands, had been evaluated and diagnosed with CTS, and that "it is as likely as not or at least possible" that the Veteran's CTS was incurred in or began while on active duty. In his July 2013 NOD, the Veteran denied having reported onset during firefighter training to the June 2011 VA examiner or even having been involved in firefighter training in 2006. The Veteran also reported that his "medical records upon departing from Afghanistan show tingling in both hands." The Board has not located any such record but, as stated above, the Veteran's service treatment records are incomplete. The Veteran was afforded a VA examination for peripheral nerves conditions in May 2016. The Veteran reported episodic numbness and tingling since approximately 2005. The clinician found that the Veteran's reported symptoms were not consistent with the physical findings or with the typical presentation of CTS, but did not provide an opinion as to a diagnosis that might apply to the Veteran's symptoms or as to their etiology. During a September 2016 VA treatment appointment, the Veteran reported numbness and tingling in all of the fingertips of his left hand that had been constant for the past month. The treatment provider noted the Veteran's history of CTS as well as his history of using a wrist splint to treat his symptoms and diagnosed CTS. The Veteran was afforded an additional VA examination for peripheral nerves conditions in December 2019. The Veteran reported that, while in Afghanistan, he did a lot of typing and began to experience numbness and tingling in both upper extremities. He reported that his current symptoms included mild constant pain, mild paresthesias or dysesthesias, and mild numbness. On examination, strength was normal but bicep reflexes were absent and triceps and brachioradialis reflexes were hypoactive. Sensory examination was normal. The clinician found that there was insufficient medical evidence to warrant a diagnosis of CTS and that the Veteran's symptoms were "subjective only." The clinician also noted that there was "no nerve conduction/EMG study" to support a diagnosis of CTS. The clinician did not discuss the diagnoses in the Veteran's treatment records, did not explain why absent or hypoactive reflexes constituted "subjective" symptoms, did not arrange for testing to be performed after finding it necessary to support a diagnosis, and did not provide an etiology opinion for the Veteran's symptoms. For all of these reasons, the clinician's opinion is inadequate. The Veteran was afforded an additional VA examination for peripheral nerves conditions in September 2020 but chose not to continue with the examination because he did not want to pursue this case. However, the Veteran has not withdrawn these claims. None of the VA examiners provided an opinion with regard to the etiology of the Veteran's upper extremity symptoms and, when they found that a diagnosis of CTS was not warranted, they did not address treatment records noting a diagnosis or provide an alternative diagnosis. Although it does not provide a thorough rationale, the July 2013 opinion by the Veteran's VA treating primary care physician, which is favorable to the Veteran's claim, is the only medical opinion of record with regard to the etiology of the Veteran's CTS. In light of the totality of the circumstances, and after resolving all reasonable doubt in the Veteran's favor, the evidence of record supports a finding that it is at least as likely as not that the Veteran has had bilateral CTS during the period on appeal and that it is etiologically related to his active duty service. Accordingly, the Board finds that granting service connection for bilateral CTS is the decision that is the most consistent with VA's policy to administer the law under a broad and liberal interpretation consistent with the facts of the case. 38 C.F.R. §§ 3.303 (a), 3.310. 8. CFS The Veteran contends that he has CFS as a result of his active duty service. Congress has created special rules with regard to Persian Gulf War veterans establishing entitlement to service connection. Service connection may be granted to a veteran who served in the Southwest Asia theater of operations during the Persian Gulf War who exhibits objective indications of a "qualifying chronic disability." 38 U.S.C. § 1117 (a)(1). The Persian Gulf War is defined as the period from August 2, 1990 to a future date prescribed by Presidential proclamation or by law. 38 U.S.C. § 101(33) (2012). A qualifying chronic disability is currently defined as either an undiagnosed illness or a medically unexplained chronic multisymptom illness defined by a cluster of signs or symptoms, such as chronic fatigue syndrome. 38 C.F.R. § 3.317 (a)(2). The symptoms must manifest to a degree of 10 percent or more during the presumptive periods prescribed by the Secretary or by December 31, 2021. 38 C.F.R. § 3.317 (a)(1)(i). By history, physical examination and laboratory tests, the disability cannot be attributed to any known clinical diagnosis. 38 C.F.R. § 3.317 (a)(1)(ii). Objective indications of chronic disability include both "signs" in the medical sense of objective evidence perceptible to an examining physician, and other, non-medical indicators that are capable of independent verification. 38 C.F.R. § 3.317 (a)(2)(ii)(3). Disabilities that have existed for 6 months or more and disabilities that exhibit intermittent episodes of improvement and worsening over a 6-month period will be considered chronic. 38 C.F.R. § 3.317 (a)(2)(ii)(4). The signs and symptoms which may be manifestations of undiagnosed illness or a chronic multisymptom illness include, but are not limited to, fatigue, muscle pain, and joint pain. 38 U.S.C. § 1117 (g). The existence of a current disability is the cornerstone of a claim for VA disability compensation. 38 U.S.C. § 1110. Thus, the threshold question that must be addressed here (as with any claim seeking service connection) is whether the Veteran had the disability for which service connection is sought at any time during the period on appeal. In the absence of proof of a disability during that period, there is no valid claim of service connection. See Brammer v. Derwinski, 3 Vet. App. 223, 225 (1992); see also Degmetich v. Brown, 104 F.3d 1328 (1997). Applicable VA regulations specifically define "chronic fatigue syndrome" at 38 C.F.R. § 4.88a in terms of identifying characteristics. A diagnosis of chronic fatigue syndrome requires: (1) new onset of debilitating fatigue severe enough to reduce daily activity to less than 50 percent of the usual level for at least six months; and (2) the exclusion, by history, physical examination, and laboratory tests, of all other clinical conditions that may produce similar symptoms; and (3) six or more of the following: (i) acute onset of the condition; (ii) low grade fever; (iii) nonexudative pharyngitis; (iv) palpable or tender cervical or axillary lymph nodes; (v) generalized muscle aches or weakness; (vi) fatigue lasting 24 hours or longer after exercise; (vii) headaches (of a type, severity, or pattern that is different from headaches in a pre-morbid state); (viii) migratory joint pains; (ix) neuropsychologic symptoms; (x) sleep disturbance. 38 C.F.R. § 4.88a. In his July 2006 post-deployment health assessment, the Veteran reported feeling tired after sleeping during his deployment to Afghanistan. The Veteran was afforded a VA examination for CFS in June 2011. The Veteran reported that, after his return from Afghanistan, he began having severe fatigue with a lack of motivation and severe anger problems. He reported that symptoms improved with treatment for his sleep apnea. The clinician diagnosed sleep apnea with secondary fatigue that had resolved and found that the diagnostic criteria for CFS described above were not met. The Veteran has submitted a December 2012 statement by a person who served with him in Afghanistan and reported that he was frequently tired during that deployment. The Veteran has also submitted a June 2013 statement by his spouse, who reported that he had had chronic fatigue since his return from Afghanistan. In his July 2013 NOD, the Veteran reported consistent fatigue since leaving Afghanistan and that his symptoms had not resolved. He also reported that a VA physician had told him his symptoms were due to cholesterol medication, but he responded that those symptoms had their onset prior to the prescription of that medication. He also reported that he stopped in Southwest Asia on his way to and from Afghanistan, including before and after a period of leave. Because the Board finds that the Veteran has not had CFS during the period on appeal, it is not necessary to determine whether this contention is accurate. In an August 2018 claim, the Veteran contended that his CFS was caused or aggravated by his psoriatic arthritis, which is now service-connected. Because the Board finds that the Veteran has not had CFS during the period on appeal, it is not necessary to determine whether this contention is accurate. The Veteran was afforded an additional VA examination for CFS in December 2019. The Veteran reported that his fatigue had worsened over the years and that he was sleepy during the day. The clinician noted that the Veteran "has other diagnoses that can cause symptoms of fatigue which includes depression, obesity, obstructive sleep apnea, and iron deficiency anemia." The clinician found that the Veteran did not meet the diagnostic criteria for CFS. The Veteran was most recently afforded a VA examination for his service-connected psychiatric disability in February 2020. The clinician listed the Veteran's symptoms for rating purposes as including chronic sleep impairment. The Veteran's most recent service treatment records list CFS among his active problems but, as there is no record of CFS having been diagnosed, this likely represents the Veteran's report of his medical history. The record contains no probative medical evidence of CFS during the period on appeal. The Veteran and other lay people are competent to report on matters observed or within their personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). The Board must determine on a case-by-case basis whether a particular medical issue is within the competence of a lay person. Kahana v. Shinseki, 24 Vet. App. 428 (2011). The Veteran and other people providing lay statements in this case are not shown to possess any pertinent medical training or expertise that would make them competent to diagnose him with CFS. Jandreau, 492 F.3d at 1376-77. Thus, to the extent that the lay statements express an opinion that the Veteran's current fatigue symptoms warrant a diagnosis of CFS, they are not competent medical opinions and they cannot be assigned any probative weight. The VA examiners' opinions that the Veteran's symptoms do not meet the diagnostic criteria for CFS, which were supported by findings that the symptoms noted in 38 C.F.R. § 4.88a(3) were not present, is of greater probative value than the lay contentions. As noted above, VA regulations state that at least six of those symptoms must be present to warrant a diagnosis of CFS. The Board also notes the December 2019 VA examiner's finding that the Veteran's fatigue could be attributable to among other causes, his service-connected psychiatric disability and obstructive sleep apnea. The Veteran's disability rating for unspecified chronic adjustment disorder has been at least 30 percent throughout the period on appeal; the criteria for a 30 percent rating contemplate "such symptoms as" chronic sleep impairment. The February 2020 VA examination report specifically notes sleep impairment as a symptom of the Veteran's service-connected psychiatric disability. In addition, the Veteran's disability rating for obstructive sleep apnea has been 50 percent throughout the period on appeal; the criteria for a lower 30 percent rating contemplate persistent daytime hypersomnolence. The Board therefore finds that, to the extent that the Veteran's fatigue is a manifestation of his chronic adjustment disorder or sleep apnea, that symptom is contemplated by the rating criteria for psychiatric disabilities because it is similar to sleep impairment and by the rating criteria for sleep apnea because it is similar to persistent daytime hypersomnolence, and a separate evaluation for fatigue by analogy to CFS under 38 C.F.R. § 4.20 is not warranted. The record does not contain any competent, probative evidence that the Veteran has been diagnosed with or treated for CFS by any examiner or treatment provider during the period on appeal. As the evidence does not establish that the Veteran had CFS during the period on appeal, the Board finds that service connection is not warranted. See McClain v. Nicholson, 21 Vet. App. 319, 321 (2007) (holding that current disability requirement is satisfied when a claimant "has a disability at the time a claim for VA disability compensation is filed or during the pendency of that claim,"); see also Romanowsky v. Shinseki, 26 Vet. App. 289, 293 (2013) (holding that the Board must address recent pre-claim evidence in assessing whether a current disability exists, for purposes of service connection, at the time the claim was filed or during its pendency). REASONS FOR REMAND 1. Entitlement to an initial disability rating in excess of 20 percent for left lower extremity radiculopathy is remanded. 2. Entitlement to an initial disability rating in excess of 10 percent for right lower extremity radiculopathy is remanded. The Veteran was last afforded a VA examination for his service-connected left and right lower extremity radiculopathy in December 2019. At that time, the Veteran reported no radiculopathy symptoms of more than mild severity. During a December 2020 VA treatment appointment, the Veteran reported that his bilateral leg pain had become more severe than his back pain and that his left leg pain had become severe. Although the VA examination was less than two years ago, the record thus raises the possibility that the Veteran's service-connected left and right lower extremity radiculopathy could now be more severe than the December 2019 examination report reflects. "Where the record does not adequately reveal the current state of the claimant's disability, a VA examination must be conducted." Schafrath v. Derwinski, 1 Vet. App. 589, 595 (1991). A remand for a new examination is thus warranted. 3. Entitlement to disability ratings in excess of 10 percent from February 1, 2011 to December 1, 2019, and in excess of 20 percent on and after December 2, 2019, for degenerative joint disease of the lumbar spine is remanded. Because a remand is warranted for a new examination for the Veteran's radiculopathy claims and it is possible that the examiner will choose to do an examination for back conditions that includes radiculopathy findings as opposed to one limited to peripheral nerve conditions, the lumbar spine claim is inextricably intertwined with this remand and the Board cannot fairly proceed in adjudicating it until the radiculopathy claims have been resolved. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991); see also Tyrues v. Shinseki, 23 Vet. App. 166, 178 (2009). 4. Service connection for a hernia, including an inguinal hernia, a hiatal hernia, a diaphragmatic hernia, and diastasis recti is remanded. Once VA undertakes the effort to provide an examination when developing a service connection claim, even if not statutorily obligated to do so, it must provide one that is adequate for purposes of the determination being made. Barr v. Nicholson, 21 Vet. App. 303, 311 (2007). The Veteran was most recently afforded a VA examination for hernias in December 2019. The clinician's opinion that it was less likely than not that the Veteran's diaphragmatic hernia was incurred in or caused by active duty service was based on a finding that it is a congenital condition. Service connection may be granted for diseases, but not defects, of congenital, developmental, or familial origin. VAOPGCPREC 82-90 (July 18, 1990); VAOPGCPREC 67-90 (July 18, 1990). In differentiating the two categories, VA's Office of General Counsel has stated that, when viewed in the context of 38 C.F.R. § 3.303 (c), the term "defects" would be definable "as structural or inherent abnormalities or conditions which are more or less stationary in nature." VAOPGCPREC 82-90. In contrast, a "disease" refers to a condition considered capable of improving or deteriorating. Id. Additionally, a congenital defect can still be subject to superimposed disease or injury. VAOPGCPREC 82-90. If such superimposed disease or injury does occur during service, service connection may be warranted for the resulting disability. Id. In sum, service connection is available for congenital diseases that first manifest in service or are aggravated in service. Service connection is not available for congenital defects, but service connection may be awarded for disease or injury that is superimposed upon the congenital defect during service. Quirin v. Shinseki, 22 Vet. App. 390, 394 (2009); Monroe v. Brown, 4 Vet. App. 513, 515 (1993); VAOPGCPREC 82-90. The December 2019 VA examination did not address the questions pertinent to service connection for congenital disabilities. For these reasons, a remand is warranted to obtain an additional medical opinion. The matters are REMANDED for the following action: 1. Arrange for the Veteran to have an examination by an appropriate clinician for the purpose of determining the current severity of his left and right lower extremity radiculopathy. The electronic claims file must be made available to the clinician for review. The clinician is to provide a detailed review of the Veteran's pertinent medical history, current complaints, and the nature and extent of any symptoms of his service-connected left and right lower extremity radiculopathy. Although an independent review of the claims file is required, the Board directs the clinician's attention to a December 2020 VA treatment record in which the Veteran reported increased leg pain, with both legs being worse than the back and the left being severe, and that his symptoms included frequent urination. 2. Arrange for an opinion by an appropriate clinician for the purpose of determining the etiology of the Veteran's hernia, including an inguinal hernia, a hiatal hernia, a diaphragmatic hernia, and diastasis recti. The entire claims file and a copy of this remand must be made available to the clinician for review. A new examination is only required if deemed necessary by the clinician. The clinician is advised that a disability is "current" if present at any point during the period on appeal, which began on February 1, 2011, even if it subsequently resolved. The clinician must provide opinions as to the following: a. As a threshold question, whether it is at least as likely as not (a probability of 50 percent or greater) that the Veteran's diaphragmatic hernia is congenital. The Board must ask this question because the December 2019 VA examiner's opinion was based on a finding that it was congenital. If, and only if, the clinician finds that the Veteran's diaphragmatic hernia is congenital, the clinician should also provide opinions as to the following: i) Whether the Veteran's diaphragmatic hernia is a developmental defect or a developmental disease. For VA purposes, a defect differs from a disease in that a defect is "more or less stationary in nature," while a disease is "capable of improving or deteriorating." ii) If the clinician finds that the Veteran's diaphragmatic hernia is a developmental or congenital defect, the clinician must provide an opinion as to whether it is at least as likely as not that the Veteran sustained any superimposed disease or injury on such defect during his active duty service. iii) If the clinician finds that the Veteran's diaphragmatic hernia is a developmental or congenital disease, the clinician must provide an opinion as to whether it is at least as likely as not that it was incurred in or aggravated beyond the normal course of the condition by active duty service. b. Whether the Veteran's hernia clearly and unmistakably existed prior to his January 2010 to January 2011 period of active duty service. c. If the answer to b) is yes, whether the Veteran's hernia was clearly and unmistakably not aggravated (i.e., not permanently worsened beyond the natural progression) during or as a result of service. d. If the answer to b) or c) is no, with regard to his January 2010 to January 2011 period of active duty service, whether it is at least as likely as not (50 percent or greater probability) that the Veteran's hernia had its origin in service or is related to the Veteran's active service. e. With regard to his April 2005 to August 2006 period of active duty service, whether it is at least as likely as not (50 percent or greater probability) that the Veteran's hernia had its origin in service or is related to the Veteran's active service. Although an independent review of the claims file is required, the Board calls the clinician's attention to the following: a. A January 2006 service treatment record noting the Veteran's report of a one-month history of abdominal pain. b. A July 2006 service treatment record noting the Veteran's report of abdominal pain. c. A September 2006 post-deployment examination noting a referral for surgery for "Abd Pain/Hernia." d. A June 2007 VA treatment record noting the Veteran's report of a diagnosis of a right inguinal hernia by his VA primary care physician, as well as the Veteran's report of occasional discomfort and similar symptoms in Afghanistan. e. A June 2011 VA examination for esophagus and hiatal hernia conditions, including the Veteran's reports regarding his symptoms and the examiner's diagnosis of diastasis recti. f. A January 2015 VA treatment record noting a March 2013 diagnosis of a "hiatus hernia." g. The December 2019 VA examination report, including the Veteran's reports regarding his symptoms and the examiner's diagnosis of a diaphragmatic hernia. The rationale for any opinion expressed should be provided. Note that the Veteran's service treatment records are incomplete and the fact that a disability is not mentioned in treatment records cannot serve as the sole basis for a negative finding. If an opinion cannot be made without resort to speculation, the clinician should so state and provide reasoning as to why a conclusion would be so outside the norm that such an opinion is not possible. 3. Ensure that the directives specified in this remand have been implemented. If they have not, appropriate corrective action must be undertaken before readjudication. Stegall v. West, 11 Vet. App. 268 (1998) 4. Then, readjudicate the claims, including the intertwined lumbar spine claim. If any decision is unfavorable to the Veteran, issue a Supplemental Statement of the Case and allow the applicable time for response. Then, return the case to the Board. D. Martz Ames Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Ryan Frank, 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.