Citation Nr: 21057721 Decision Date: 09/16/21 Archive Date: 09/16/21 DOCKET NO. 16-16 904 DATE: September 16, 2021 ORDER Entitlement to service connection for a left knee disorder, as secondary to service-connected right knee disorder, is granted. Entitlement to service connection for a right ankle disorder, to include as secondary to service-connected right knee disorder, is denied. Entitlement to service connection for a right hip disorder, as secondary to service-connected right knee disorder, is granted. Entitlement to service connection for a left hip disorder, as secondary to service-connected right knee disorder, is granted. Entitlement to service connection for a low back disorder, to include arthritis, as secondary to service-connected right knee disorder, is granted. Entitlement to service connection for a cervical spine disorder, to include arthritis, as secondary to service-connected low back disorder, is granted. Entitlement to service connection for left lower leg sciatica, as secondary to service-connected low back disorder, is granted. REMANDED Entitlement to a TDIU is remanded. FINDINGS OF FACT 1. The preponderance of the evidence demonstrates that the Veteran's left knee disorder, to include arthritis, is caused or aggravated by a service-connected right knee disorder and the resulting compensatory walking strategies with biomechanical and kinematic changes. 2. The preponderance of the evidence is against finding that a right ankle disorder, to include arthritis, was clearly and unmistakably aggravated by service or is aggravated by a service-connected disability. 3. The preponderance of the evidence demonstrates that the Veteran's right hip disorder, to include arthritis, is caused or aggravated by a service-connected right knee disorder and the resulting compensatory walking strategies with biomechanical and kinematic changes. 4. The preponderance of the evidence demonstrates that the Veteran's left hip disorder, to include arthritis, is caused or aggravated by a service-connected right knee disorder and the resulting compensatory walking strategies with biomechanical and kinematic changes. 5. The preponderance of the evidence demonstrates that the Veteran's low back disorder, to include arthritis, is caused or aggravated by a service-connected right knee disorder and the resulting compensatory walking strategies with biomechanical and kinematic changes. 6. The preponderance of the evidence demonstrates that the Veteran's cervical spine disorder, to include arthritis, is caused or aggravated by a service-connected low back disorder. 7. The preponderance of the evidence demonstrates that the Veteran's left lower leg sciatica is caused or aggravated by a service-connected low back disorder. CONCLUSIONS OF LAW 1. The criteria for service connection for a left knee disorder due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 2. The criteria for service connection for a right ankle disorder due to service or service-connected disease or injury are not met. 38 U.S.C. §§ 1110, 1131, 1153, 5107; 38 C.F.R. §§ 3.102, 3.304, 3.310. 3. The criteria for service connection for a right hip disorder due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 4. The criteria for service connection for a left hip disorder due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 5. The criteria for service connection for a low back disorder due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 6. The criteria for service connection for a cervical spine disorder due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 7. The criteria for service connection for a left lower leg sciatica due to service or service-connected disease or injury are met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the United States Navy from April 1969 to July 1970. These issues were remanded by the Board in May 2019 and April 2021 decisions. The issues have since returned to the Board for appellate review. Service Connection Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. § 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a Veteran must show: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service - the so-called "nexus" requirement. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004)). Service connection may be granted for any disease initially diagnosed after discharge when all of the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). In addition, service connection for certain chronic diseases, including arthritis, may be established on a presumptive basis by showing that the condition manifested to a degree of 10 percent or more within one year from the date of separation from service. 38 U.S.C. §§ 1101, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.307, 3.309(a); Fountain v. McDonald, 27 Vet. App. 258, 271-72 (2015). Although the disease need not be diagnosed within the presumption period, it must be shown, by acceptable lay or medical evidence, that there were characteristic manifestations of the disease to the required degree during that time. 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(a). For the showing of chronic disease in service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. If chronicity in service is not established, a showing of continuity of symptoms after discharge may support the claim. 38 C.F.R. §§ 3.303(b), 3.309 (2017); Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). The Federal Circuit has held that the theory of continuity of symptomatology can be used only in cases involving those conditions explicitly recognized as chronic. See Walker, supra; 38 C.F.R. § 3.309(a). Secondary service connection is warranted where a disability is proximately due to or the result of a service-connected disease or injury. 38 C.F.R. § 3.310(a). Briefly, the threshold legal requirements for a successful secondary service connection claim are: (1) Evidence of a current disability for which secondary service connection is sought; (2) a disability for which service connection has been established; and (3) competent evidence of a nexus between the two. In relevant part, 38 U.S.C. § 1154(a) requires that VA give "due consideration" to "all pertinent medical and lay evidence" in evaluating a claim for disability or death benefits. Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). The United States Court of Appeals for the Federal Circuit has held that "[l]ay evidence can be competent and sufficient to establish a diagnosis of a condition when (1) a layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional." Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). Once evidence is determined to be competent, the Board must then determine whether such evidence is also credible. See Layno, 6 Vet. App. at 469. When there is an approximate balance of positive and negative evidence regarding the merits of an issue material to the determination of the matter, the benefit of the doubt in resolving each such issue shall be given to the claimant. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. When all of the evidence is assembled, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the appellant prevailing in either event, or whether a fair preponderance of the evidence is against the claim, in which case the claim is denied. Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 1. Entitlement to service connection for a left knee disorder, to include as secondary to service-connected right knee disorder, is granted. The Veteran asserts that he is entitled to service connection for a left knee disorder on a direct basis and secondary basis. As outlined below, the preponderance of the evidence of record demonstrates that the Veteran's left knee disorder is caused or aggravated by service-connected right knee disorder. As such, service connection is established on a secondary basis. In a February 1969 service treatment record (STR), the Veteran sought treatment for a bruised kneecap form fall off a ladder. The medical provider observed a bone bruise, but no broken bones. The July 1970 STR separation examination shows the Veteran's lower extremities to be normal. June 2010 VA imaging demonstrated the Veteran has mild osteoarthritis in the left knee. The imaging record states thickening on the right side probably due to old healed lesion. The right knee is shown to have moderate osteoarthritis. In an October 2011 VA treatment record, the Veteran complained of bilateral knee pain. The Veteran stated he had an onset of pain during service in 1969. The medical provider stated the history of an initial injury in 1969 with reinjury to the right knee in 1993 with a fall from a ladder. The medical provider stated the Veteran underwent bilateral knee surgical procedure in 1985 and "was better until 1993." In a November 2012 VA treatment record, the medical provider observed the Veteran to have a slightly antalgic gait. In a July 2013 VA knee examination, the examiner indicated the Veteran has a diagnosis of bilateral degenerative joint disease (DJD). The Veteran stated he has a history of falling and bruising his kneecap during service. He stated he was diagnosed with bruised kneecap in a February 1970 STR. He stated he was assigned to three days of light duty as a result. The Veteran stated he was coming down stairs and fell on his knees and hands. He stated he sought treatment in 1982. He stated he has had difficulty walking due to pain. He stated his right knee is worse than his left knee. The July 2013 VA examiner opined that the Veteran's knee disorder is less likely than not caused by service. The examiner reasoned that the Veteran's separation examination is silent for any other knee issues. The examiner stated it would be difficult to state one isolated injury resulted in bilateral knee DJD. The examiner stated the Veteran worked in manual labor and with normal wear and tear, aging can contribute to his current knee disorder. In an August 2013 VA treatment record, the medical provider assessed the Veteran to have muscle weakness and a gait deficit. In a February 2015 private medical opinion, the medical provider opined that the Veteran's left knee disorder is more likely than not caused by service. The medical provider reasoned that the Veteran suffers from left knee pain that is constant and intensifies with standing, sitting, walking, stairs, and transitioning from a seated to standing position. The medical provider noted the Veteran underwent surgery and ambulates with a cane or walker when necessary. On examination, the medical provider found the Veteran's left knee to be positive for lateral instability and crepitus. The medical provider indicated the Veteran has a diagnosis of advanced traumatic residual degenerative joint disease and lateral instability. Therefore, it is more likely than not that the left knee disorder is directly and causally related to injury as discussed in the history. In a December 2017 VA treatment record, the medical provider observed the Veteran to use a cane in his left hand and to demonstrate a limp on the left side. At that time, the Veteran complained of chronic pain in the knees. He stated the pain began in 1969 when he fell ten feet during service. He stated he developed pain in the knees. In a May 2019 VA treatment record, the medical provider observed the Veteran to have an antalgic gait and to use a cane. On the February 2020 VA knee examination, the examiner indicated the Veteran has a diagnosis of left knee osteoarthritis. The Veteran stated that his left knee disorder began in 1969 when he fell from stairs on the ship and landed on his knees. He stated he experienced sharp and shooting pain. He stated that he currently experiences cracking, popping, and has no cartilage in the knees. The February 2020 examiner opined that the Veteran's left knee disorder is less likely than not caused by service. The examiner reasoned that although the Veteran experienced a 1970 fall in service and injured his knees, wrists, back, and hips, the examiner is unable to find evidence in the STRs or private treatment records that the Veteran continuously complained of or sought treatment for his left knee disorder from 1970 to 2010. Therefore, the lack of continuity of complaints and seeking treatment for over 40 years does not suggest a connection between his current arthritis in the left knee and his in-service injury. The February 2020 VA examiner also opined that the Veteran's left knee disorder is less likely than not proximately due to or the result of the service-connected right knee disorder. The examiner reasoned that although the Veteran experienced a fall in service, the examiner is unable to find evidence in the STRs or private treatment records that the Veteran continuously complained of or sought treatment for his left knee disorder from 1970 to 2010. Also, the examiner stated that the Veteran's left knee and right knee are different anatomical locations; therefore, the right knee cannot directly cause or aggravate the degenerative arthritis of the left knee. In a February 2021 private medical opinion, the medical provider opined that it is at least as likely as not that the Veteran's left knee arthritis is related to or aggravated by his service-connected right knee disorder with associated compensatory walking strategies with biomechanical and kinematic changes. The medical provider reasoned that due to the severity of the Veteran's service-connected right knee disorder pathology and associated pain, he developed an antalgic gait pattern with limping. The medical provider stated that the medical literature associates secondary biomechanical changes that cause abnormal kinetics to occur within both lower extremity joints, and per the medical literature, hastened the development and the progression of the Veteran's left knee arthritis. The medical provider specifically stated that it is widely accepted and well documented in medical literature studies that orthopedic impairments located in one region of the body affect and are associated with the musculoskeletal function and symptoms of a completely separate region, including arthritis. The medical provider highlighted that biomechanical changes at the hip, knee, and ankle joints during gait are associated with knee arthritis. In a March 2021 statement, the Veteran asserts that he is entitled to service connection for a left knee disorder as secondary to service-connected right knee disorder. He stated his right knee causes him to walk unevenly. He stated he experiences locking, swelling, popping, instability, and pain in the left knee. He stated that use of the knee causes pain. On the May 2021 VA knee examination, the examiner indicated the Veteran has a diagnosis of bilateral knee arthritis. The Veteran stated he injured his bilateral knees during service. He stated the left knee was not documented in the medical records. He stated that because his right knee went out, he had to shift his weight to the left knee. He stated the cartilage wore out in the left knee. He stated he underwent bilateral knee surgery approximately 10 to 15 years ago. The examiner opined that the Veteran's left knee disorder is less likely than not caused or aggravated by service-connected right knee disorder. The examiner reasoned that the left knee arthritis is more likely caused by morbid obesity, prior occupation in construction, age, and genetics. The examiner stated the Veteran does not have leg length discrepancy. The examiner found the Veteran to have antalgic gait, but no altered gait mechanics. On the June 2021 VA knee examination, the examiner opined that the Veteran's left knee disorder is less likely than not caused by service-connected right knee disorder. The examiner reasoned that arthritis in one joint does not cause arthritis in another joint. The examiner stated that a causal relationship has failed to be demonstrated. The examiner stated it is not unusual for two joints to share properties in the same person, but one joint's disease does not 'spread' to another or cause damage to it. The examiner concluded that the Veteran's left knee arthritis is less likely than not related to the anterior instability in the right knee. Based on the record, the Board finds the preponderance of the evidence is in favor of the Veteran's claim. The Board finds inadequacies in the VA examinations and opinions. First, the February 2015 private examination did not adequately explain how the right knee disorder caused or aggravated the left knee disorder. Secondly, the Board finds that the February 2020 VA examiner did not address the Veteran's gait and the May 2021 and June 2021 VA examinations did not address the Veteran's documented limp and use of a cane on the left side. However, the Board finds that the February 2021 private medical opinion was based on a full review of the claims file and included an explanation of the walking mechanics and medical literature to support of the conclusion. Accordingly, the Board finds that the evidence for the claim of entitlement to service connection for a left knee disorder is more persuasive. Therefore, reasonable doubt must be resolved in favor of the Veteran, and entitlement to service connection for a left knee disorder is warranted. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 2. Entitlement to service connection for a right ankle disorder, to include as secondary to service-connected right knee disorder, is denied. The Veteran asserts that he is entitled to service connection for a right ankle disorder. However, as outlined below, the preponderance of the evidence of record demonstrates that the Veteran's right ankle disorder clearly and unmistakably existed prior to service and is clearly and unmistakably not aggravated by service. Also, the evidence of record does not demonstrate that the Veteran's right ankle disorder is aggravated by the service-connected right knee disorder. In addition to the service connection requirements above, under ordinary circumstances for veterans of active military wartime service or peacetime service on or after January 1, 1947, for purposes of 38 U.S.C. §§ 1110, 1131, and 1137, every veteran shall be taken to have been in sound condition when examined, accepted, and enrolled for service, except as to defects, infirmities, or disorders noted at the time of the examination, acceptance, and enrollment, or where clear and unmistakable evidence demonstrates that the injury or disease existed before acceptance and enrollment and was not aggravated by such service. 38 U.S.C. § 1111. The presumption of soundness may only be rebutted by clear and unmistakable evidence that the Veteran's disability was both preexisting and not aggravated by service. Wagner v. Principi, 370 F.3d 1089 (Fed. Cir. 2004); 38 C.F.R. § 3.304(b). This statutory provision is referred to as the 'presumption of soundness.' Horn v. Shinseki, 25 Vet. App. 231, 234 (2012). In VAOGCPREC 3-2003, VA's General Counsel reinforced that the presumption of soundness is rebutted only where clear and unmistakable evidence shows both that the condition existed prior to service and that it was not aggravated by service. The General Counsel concluded that 38 U.S.C. § 1111 requires VA to bear the burden of showing the absence of aggravation in order to rebut the presumption of sound condition. See Wagner v. Principi, 370 F.3d 1089 (Fed. Cir. 2004). Therefore, where there is evidence showing that a disorder manifested or was incurred in service, and this disorder is not noted on the Veteran's entrance examination report, this presumption of soundness operates to shield the Veteran from any finding that the unnoted disease or injury preexisted service. See Gilbert v. Shinseki, 26 Vet. App. 48, 52-53 (2012); see also 38 C.F.R. § 3.304(b) ('Only such conditions as are recorded in examination reports are considered as noted.'). This presumption is only rebutted where the evidence clearly and unmistakably shows that the Veteran's disability (1) existed before acceptance and enrollment into service and (2) was not aggravated by service. See Wagner, 370 F.3d at 1096; Bagby v. Derwinski, 1 Vet. App. 225 (1991). The two parts of this rebuttal standard are referred to as the 'preexistence prong' and the 'aggravation prong.' Horn, 25 Vet. App. at 234. The aggravation prong may be met by establishing that there was no increase in disability during service or that any increase in disability was due to the natural progress of the preexisting condition. Wagner, 370 F.3d at 1096; see also 38 U.S.C. § 1153. If this burden is met, then the Veteran is not entitled to service-connected benefits, and, conversely, where the presumption is not rebutted, the Veteran's claim is one for service connection, and not aggravation. Wagner, 370 F.3d at 1096. In an April 1969 STR enlistment record of medical care, the medical provider noted the Veteran had a right ankle injury in 1967. The July 1970 STR separation examination shows the Veteran's lower extremities to be normal. In an April 1971 post-service treatment record, the medical provider noted the Veteran has an old ankle injury. In an April 2008 private treatment record, the Veteran complained of a right ankle injury. On the August 2015 VA ankle examination, the examiner indicated the Veteran has a right ankle sprain. The Veteran stated his symptoms began in 1975. He stated he was in Seattle when he sprained his ankle, which aggravated the right ankle sprain more. He stated he experienced pain when he put weight and pressure on the right ankle. He stated the right ankle sprain has gradually worsened with increased pain. The August 2015 VA examiner opined that the Veteran's right ankle disorder, which clearly and unmistakably existed prior to service, was aggravated beyond its natural progression by an in-service injury, event, or illness. The examiner reasoned that after review of the medical records and examination, the Veteran sprained his ankle in 1970 and it is difficult to tell how severe the ankle sprain was, however load and weight will put pressure on the injured ankle and will result in further damage. A November 2015 VA addendum ankle opinion stated that the Veteran's right ankle fracture, which clearly and unmistakably existed prior to service, is not permanently increased by military service, but is increased due to the natural progression of the disease/injury. The examiner reasoned that that the August 2015 VA examination revealed a normal initial range of motion, no additional loss of function or range of motion, no pain, no weakness, and no fatigability or incoordination that significantly limits the functional ability with flare-ups. The examiner commented there are no complications associated with the right ankle from the information gathered. Therefore, there is no aggravation due to military service. The February 2020 VA ankle examiner indicated the Veteran has a diagnosis of right ankle sprain. The Veteran stated that his right ankle disorder began in 1969 when he fell from stairs on the ship and twisted his ankles. He stated that he experienced a sharp pain, swelling, and instability. The Veteran stated he currently experiences sharp pain, swelling, and instability in the right ankle. The February 2020 VA examiner opined that the Veteran's right ankle disorder is less likely than not aggravated beyond its natural progression by active service. The examiner reasoned that the Veteran's right ankle fracture occurred in 1967. And the Veteran had a February 1970 fall during service where he sustained injury to his knees, wrists, back, ankles, and hips. The examiner stated that he was unable to find evidence of aggravation to the right ankle in his STRs or private treatment records by that he continuously complained of or sought treatment for his right ankle disorder. On the July 1970 separation examination, there are no ankle conditions listed on the exam. On the May 2021 VA ankle examination, the examiner did not indicate if the Veteran had a diagnosis of the right ankle. The Veteran stated that his ankle symptoms began in service when he fell from the stairs and hit the bulkhead. He stated he then hit the deck. He sought treatment and was treated for bruised knees. He stated that his right ankle now swells up and hurts when he walks. On examination, the examiner observed the Veteran's right ankle to have abnormal range of motion and pain. The examiner opined that the right ankle disorder is less likely than not caused or aggravated by service-connected right knee disorder, to include an altered gait. The examiner reasoned that the Veteran's right ankle swelling and tenderness are most likely caused and aggravated by obesity, peripheral vascular disease, diabetes, and chronic kidney disease stage III. The examiner stated there is no leg length discrepancy. Also, there is antalgic gait, but no altered gait mechanics. Upon review of the record, the Board finds that the Veteran's right ankle disorder did clearly and unmistakably preexist service and was clearly and unmistakably not aggravated thereby, and the presumption of soundness does not attach. 38 C.F.R. § 3.304(b). As to the 'preexistence prong,' the record includes an August 2015 VA opinion, February 2020 VA opinion, and a November 2015 VA opinion, all with the examiners' conclusion that, following a review of the Veteran's records, there was clear and unmistakable evidence that the right ankle disorder preexisted service. However, the August 2015 VA opinion opined that the right ankle was aggravated beyond its natural progression by service and the November 2015 and February 2020 VA examiners opined that the Veteran's right ankle was clearly and unmistakably not aggravated beyond its natural progression by an in-service injury, event, or illness. See Harris v. West, 203 F.3d. 1347 (Fed. Cir. 2000) (determination of the existence of a pre-existing condition may be supported by a later medical opinion based upon statements made by the veteran about the pre-service history of his/her condition). The VA examiners noted the April 1969 STR enlistment record of medical care and the medical provider's note that the Veteran had a right ankle injury in 1967, prior to service. Given the foregoing, to include the medical records demonstrating an already existing right ankle disorder prior to entrance to service and the VA examiners' opinions, the Board finds that the evidence clearly and unmistakably shows that the Veteran's right ankle disorder existed prior to his active service. Wagner, supra; Horn v. Shinseki, 25 Vet. App. 23 (2012). With regard to the 'aggravation prong,' the Board finds that there is clear and unmistakable evidence that the Veteran's preexisting right ankle disorder was not aggravated during military service beyond its natural progression. The November 2015 and February 2020 VA examiners opined that the Veteran's right ankle fracture, which clearly and unmistakably existed prior to service, was clearly and unmistakably not permanently increased by military service, but is increased due to the natural progression of the disease/injury. The November 2015 VA examiner noted that the August 2015 VA examination revealed a normal initial range of motion and no complications associated with the right ankle. The November 2015 and February 2020 VA examiners' opinions are considered to be highly probative, as they are shown to have based on a review of the Veteran's claims file and are consistent with the evidence or record, namely the Veteran's STRs, VA examination, and are accompanied by a sufficient explanation. The Board finds the August 2015 VA examination to be less probative, as the examiner found it is difficult to tell how severe the ankle sprain was and did not reference the STRs or findings of the VA examination in making the opinion. Given the foregoing, the Board finds that the most probative evidence of record clearly and unmistakably shows that the Veteran's right ankle disorder preexisted and was not aggravated by his active duty service. Wagner, 370 F.3d at 1096; Horn, 25 Vet. App. at 234. There is no basis to allow the Veteran's claim for service connection for his preexisting right ankle disorder. Both the facts and the medical evidence, overall, provide highly significant evidence against the claim that meets this high standard. Also, the Veteran asserts that his right ankle disorder is caused or aggravated by his service-connected right knee disorder. Based on the foregoing, there is no evidence that the Veteran's right ankle disorder is caused or aggravated by a service-connected disability. Consequently, service connection for a right ankle disorder on the basis that such is caused or aggravated by a service-connected right knee disorder is not warranted. There is no evidence that the Veteran's right ankle disorder is caused or aggravated by service-connected right knee disorder. The Veteran's post service treatment records are silent for an opinion relating the right ankle disorder to service-connected right knee disorder. The only competent evidence in the record that addresses this question is the May 2021 VA medical opinion, which stated that the Veteran's right ankle disorder is not caused or aggravated by service-connected right knee disorder. As there is no other evidence to the contrary, and the May 2021 VA medical opinion was based on a full review of the record as well as an interview and examination of the Veteran, the Board finds it persuasive. Consideration has been given to the Veteran's assertion that his right ankle disorder was either aggravated by his active service, had its onset therein, or is caused or aggravated by service-connected right knee disorder. Although lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), as to the specific issue in this case, a right ankle disorder that preexisted service and may be aggravated by a service-connected disability, falls outside the realm of common knowledge of a lay person. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 n.4 (Fed. Cir. 2007) (lay persons not competent to diagnose cancer). Musculoskeletal disabilities are not the type of conditions that are readily amenable to mere lay diagnosis or probative comment regarding its etiology. See Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009); Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007); and Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007). That is, although the Board readily acknowledges that the Veteran is competent to report his right ankle symptoms, there is no indication that he is competent to provide an opinion that the reported right ankle symptoms represented an aggravation of his right ankle disorder (as opposed to the natural waxing and waning of the condition). The Veteran has not been shown to possess the requisite medical training, expertise, or credentials needed to render a diagnosis or a competent opinion as to medical causation for the above-cited right ankle disorder. Nothing in the record demonstrates that the Veteran has received any special training or acquired any medical expertise in evaluating a musculoskeletal disorder. See King v. Shinseki, 700 F.3d 1339, 1345 (Fed. Cir. 2012). Accordingly, this lay evidence does not constitute competent medical evidence and lacks probative value. As there is no competent medical evidence of record to support the claim for service connection for a right ankle disorder, the preponderance of the evidence is against the claim, and the doctrine of reasonable doubt is not for application. See 38 U.S.C. § 5107(b); Gilbert v. Derwinski, 1 Vet. App. 49, 55-57 (1990). 3. Entitlement to service connection for a right hip disorder, as secondary to service-connected right knee disorder, is granted. 4. Entitlement to service connection for a left hip disorder, as secondary to service-connected right knee disorder, is granted. The Veteran asserts that he is entitled to service connection for a bilateral hip disorder on a direct basis and secondary basis. The preponderance of the evidence demonstrates that the Veteran's bilateral hip disorder is caused or aggravated by service-connected right knee disorder. As such, service connection is established on a secondary basis. The July 1970 STR separation examination shows the Veteran's lower extremities to be normal. A February 2015 private medical opinion found the Veteran's bilateral hip degenerative joint disease is more likely than not secondary to the bilateral knee disorder. The medical provider reasoned that the Veteran has developed significant pain and dysfunction in the bilateral hips. The medical provider stated the bilateral hip disorder is secondary to the chronic and constant compensation and adaption to the weight shifting and altered gait generated by the bilateral knee disorder. The medical provider stated the Veteran has pain which intensifies dramatically with standing and walking. The medical provider stated that this opinion agrees with the VA orthopedic surgeon regarding causation. In a December 2017 VA treatment record, the Veteran complained of chronic pain in the hips. He stated the pain began in 1969 when he fell ten feet during service. He stated he developed pain in the hips. On the February 2020 hip examination, the examiner indicated the Veteran has bilateral hip degenerative joint disease. The Veteran stated the bilateral hip disorder began in 1969 when he fell from stairs on the deck of the ship. He stated he experienced a sharp and dull pain. He stated he currently experiences a sharp and stabbing pain that travels to his toes. The February 2020 VA examiner opined that the Veteran's left hip disorder is less likely than not caused by service. The examiner reasoned that although the Veteran experienced an in-service February 1970 fall where he injured his knees, wrists, back, ankles, and hips, the examiner was unable to find evidence in the STRs or private treatment records that the Veteran continuously complained or sought treatment for his left hip disorder form 1970 to 2015. Also, the examiner found that the lack of continuity of complaints and seeking treatment for over 45 years does not suggest a connection between his current degenerative arthritis of the left hip with his in-service injury. The February 2020 VA hip examiner opined that the Veteran's bilateral hip disorder is less likely than not proximately due to or the result of the Veteran's service-connected right knee disorder. The examiner reasoned that the Veteran had a February 1970 fall during service. The examiner stated that a result, the Veteran sustained injury to his knees, wrists, back, ankles, and hips. The examiner noted the Veteran was treated with light duty. The examiner stated that he is unable to find evidence in the STRs or private medical records that the Veteran continuously complained of or sought treatment for his bilateral hip disorder from 1970 to 2015. Also, the examiner stated that the right and left hip and right knee are in different anatomical locations and the right knee cannot directly cause or aggravate degenerative arthritis of the right or left hip. Also, as a result of the different anatomical locations, the right knee cannot directly cause or aggravate arthritis in the right or left hip. In the February 2021 private medical opinion, the medical provider opined that the Veteran's left hip disorder is more likely than not secondary to, related to, and/or aggravated by service-connected right knee disorder with associated compensatory posture and movement with biomechanical and kinematic changes. The medical provider stated that the Veteran has a current diagnosis of mild osteoarthritic change in the left hip from December 2018. The medical provider reasoned that due to the severity of the service-connected right knee disorder, the Veteran developed an altered center of gravity and antalgic gait pattern with limp that the medical literature associates with secondary biomechanical changes that cause abnormal kinematics to occur within both of the lower extremity joints, and therefore (based on medical literature), hastened the development and progression of his left hip arthritic changes. In a March 2021 statement, the Veteran asserted that he is entitled to service connection for his left hip disorder secondary to service-connected right knee disorder. He stated the right knee disorder has caused him to walk unevenly. He stated that he experiences pain, limited movement, weakness, and popping. He stated that prolonged car rides and house chores exacerbate the pain in the left hip. He stated he requires the use of a cane to help him walk. On the May 2021 VA hip examination, the examiner indicated the Veteran has bilateral hip arthritis. The Veteran stated that he experiences constant pain. On examination, the examiner observed the Veteran to have abnormal or outside of normal range of motion in the bilateral hips. The examiner opined that the Veteran's bilateral hip disorder is less likely as not caused or aggravated by his service-connected right ankle disorder. The examiner reasoned that the Veteran's bilateral hip arthritis is most likely caused by morbid obesity, prior occupation in construction, age, and genetics. The examiner stated that the Veteran has no leg length discrepancy; he has antalgic gait but no altered gait mechanics. On the June 2021 VA medical opinion, the examiner opined that that the Veteran's left hip disorder is less likely than not caused or aggravated by the Veteran's service-connected right knee disorder. The examiner reasoned that arthritis in one joint does not cause arthritis in another joint. The examiner stated that such a causal relationship is not demonstrated. The examiner stated that it is not unusual for two joints to share properties in the same person, but one joint's disease does not 'spread' to another or cause damage to it. Therefore, the examiner concluded that the Veteran's left hip disorder is less likely than not related to the right knee disorder. Based on the record, the Board finds the preponderance of the evidence is in favor of the Veteran's claim of entitlement to service connection for a bilateral hip disorder. The Board finds inadequacies in the VA examinations and opinions. First, the February 2015 private examination did adequately explain how the right knee disorder caused or aggravated the bilateral hip disorder with altered gait and weight shifting. Secondly, the Board finds that the February 2020 VA examiner did not address the Veteran's gait and the May 2021 and June 2021 VA examinations did not address the Veteran's documented limp and use of a cane on the left side. However, the Board finds that the February 2021 private medical opinion was based on a full review of the claims file and included an explanation of the walking mechanics and medical literature to support of the conclusion. Accordingly, the Board finds that the evidence for the claim of entitlement to service connection for a bilateral hip disorder is more persuasive. Therefore, reasonable doubt must be resolved in favor of the Veteran, and entitlement to service connection for a bilateral hip disorder is warranted. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 5. Entitlement to service connection for a low back disorder, as secondary to service-connected right knee disorder, is granted. The Veteran asserts that he is entitled to service connection for a low back disorder on a direct basis and secondary basis. As outlined below, the preponderance of the evidence demonstrates that the Veteran's low back disorder is caused or aggravated by service-connected right knee disorder. As such, service connection is established on a secondary basis. The July 1970 STR separation examination shows the Veteran's spine to be normal. In a November 2000 private treatment record, the medical provider indicated the Veteran has degenerative joint disease in the low back. The February 2015 private medical opinion stated the Veteran's low back disorder is more likely than not caused or aggravated by the in-service bilateral knee disorder. The medical provider reasoned that the Veteran developed low back pain that is constant. The medical provider stated the low back disorder is the result of the process of chronic and constant biomechanical adaptation and compensation for altered gait and weight shifting. The medical provider stated this opinion on causation is shared by the VA orthopedic surgeon. In a December 2017 VA treatment record, the Veteran complained of chronic pain in the back. He stated the pain began in 1969 when he fell ten feet during service. He stated he developed pain in the back. On the February 2020 VA back examination, the examiner indicated the Veteran has diagnoses of degenerative arthritis and intervertebral disc syndrome and bilateral lower extremity radiculopathy. The Veteran stated the low back disorder began in 1969 when he fell from stairs on the deck of a ship. He stated he experienced sharp shooting pain down his legs and numbness in the legs and needles in the feet. The Veteran stated he currently experiences sharp shooting pain, numbness in the feet, and sciatica pains. The February 2020 VA back examiner opined that the Veteran's low back disorder is less likely than not caused by service. The examiner reasoned that the Veteran had a fall in February 1970 during service. The examiner stated that in this fall the Veteran sustained injury to his knees, wrists, back, ankles, and hips. The examiner stated the Veteran was treated with medications and light duty. The examiner note the Veteran was diagnosed with DJD in the lumbar spine in February 2015. The examiner stated that the Veteran's DJD is related to aging and normal wear and tear. The examiner stated that he is unable to find evidence in the STRs or private medical records that the Veteran continuously complained of or sought treatment for his low back from 1970 to 2015. The examiner stated that lack of continuity of complaints and seeking treatment for over 45 years does not suggest a connection between the Veteran's current low back disorder and his injury during service. The February 2020 VA examiner also opined that the Veteran's low back disorder is less likely than not proximately due to or the result of the Veteran's service-connected right knee disorder. The examiner stated the low back and the left knee are in different anatomical locations therefore a right knee disability cannot directly cause of aggravate DJD or arthritis in the low back. Further, the examiner stated that the Veteran's low back disorder is less likely than not aggravated beyond its natural progression by the Veteran's right knee disorder. Again, the examiner stated that the low back and right knee have different anatomical locations and the right knee cannot directed cause or aggravate the DJD and arthritis of the low back. In the February 2021 private medical opinion, the medical provider opined that the Veteran's low back disorder is more likely than not secondary to, related to, and/or aggravated by his service-connected right knee disorder with associated compensatory walking strategies with biomechanical and kinematic changes. The examiner noted the Veteran was diagnosed with degenerative disc disease (DDD) in April 2011. The medical provider reasoned that the Veteran right knee disorder resulted in an antalgic gait pattern with limping and/or transfer in his center of gravity due to unequal weight distribution in the lower extremities. The medical provider stated that the medical literature associates the antalgic gait pattern with secondary biomechanical changes that cause abnormal kinematics to occur in the lower extremities, which hastened the development and progression of the Veteran's low back DDD. The medical provider cited medical literature that documents that alterations in joint kinematics affect other major joints including the feet, ankles, knees, hips, and lumbar spine and can accelerate wear on these joints by means of compensation and altered biomechanics. Also, the medical provider stated that current medical literature has linked low back pain to the biomechanical changes and alterations in joint kinematics related to compensatory strategies, antalgic gait patterns, abnormal dynamic forces in the low back, pelvis, and lower extremity joints, and the transfer of weight away from the normal center of gravity due to lower extremity joints pain and painful motion with functional limitations. The medical provider stated that this asymmetry results in increased wear and tear in the lumbar spine facet joints and discs with resultant hastened degenerative arthritic histopathological processes. In a March 2021 lay statement, the Veteran asserts that his low back disorder is secondary to service-connected right knee disorder due to the way he has been forced to walk. He stated he currently experiences low back pain that is shooting, throbbing, stabbing, aching with a pins and needles sensation, which also causes him to walk unevenly. He stated he experiences monthly muscle spasms. The May 2021 VA examiner indicated the Veteran has a diagnosis of degenerative arthritis in the low back. The examiner opined that the Veteran's low back disorder is less likely than not caused or aggravated by service-connected right knee disorder. The examiner reasoned that the Veteran's low back disorder is most likely caused by morbid obesity, prior occupation in construction, age, and genetics. The examiner stated there is no leg length discrepancy. The examiner stated there is antalgic gait, but no altered gait mechanics. The June 2021 VA medical opinion stated that the Veteran's low back disorder is less likely than not caused by the Veteran's service-connected right knee disorder. The examiner reasoned that arthritis in one joint does not cause arthritis in another joint. The examiner stated that such a causal relationship is not demonstrated. The examiner stated that it is not unusual for two joints to share properties in the same person, but one joint's disease does not 'spread' to another or cause damage to it. Therefore, the examiner concluded that the Veteran's low back disorder is less likely than not related to the right knee disorder. Based on the record, the Board finds the preponderance of the evidence is in favor of the Veteran's claim. The Board finds inadequacies in the VA examinations and opinions. First, the February 2015 private examination did adequately explain how the right knee disorder caused or aggravated the low back disorder. Secondly, the Board finds that the February 2020 VA examiner did not address the Veteran's gait and the May 2021 and June 2021 VA examinations did not address the Veteran's documented limp and use of a cane on the left side. However, the Board finds that the February 2021 private medical opinion was based on a full review of the claims file and included an explanation of the walking mechanics and medical literature to support of the conclusion. Accordingly, the Board finds that the evidence for the claim of entitlement to service connection for a low back disorder is more persuasive. Therefore, reasonable doubt must be resolved in favor of the Veteran, and entitlement to service connection for a low back disorder is warranted. 38 U.S.C. § 5107(b); Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 6. Entitlement to service connection for a cervical spine disorder, as secondary to service-connected right knee disorder, is granted. The Veteran asserts that he is entitled to service connection for a cervical spine disorder on a direct basis and secondary basis. As outlined below, the preponderance of the evidence demonstrates that the Veteran's cervical spine disorder is caused or aggravated by the now service-connected low back disorder. As such, service connection is established on a secondary basis. The July 1970 STR separation examination shows the Veteran's spine and neck to be normal. In a June 2004 private treatment record, the Veteran was assessed to have cervical radiculopathy. In a December 2004 private treatment record, the Veteran complained of neck and shoulder pain with tingling. The medical provider observed the Veteran to have decreased range of motion and spasms. The medical provider assed the Veteran to have cervical radiculopathy. In an April 2008 private treatment record, the Veteran complained of neck pain and left shoulder pain. In an August 2011 VA treatment record, the medical provider stated the Veteran did have an old neck injury treated through workers compensation and does have some neck pain and stiffness. On physical examination, the medical provider observed the neck to be tender with spasms. In an October 2011 VA treatment record, the Veteran is assessed to have a diagnosis of left side branichal cleft cyst. In an August 2013 VA treatment record, the medical provider stated the Veteran has a history of loss of consciousness with neck movement two years prior. A February 2015 private medical opinion stated the Veteran's cervical spine DJD and spondylosis is more likely than not caused by the low back disorder and thoracic spine disorder, which are related to the lower extremity injury. The medical provider reasoned that since involvement of the low back and thoracic regions, the Veteran has suffered from progressive pain in the cervical region, which intensifies with motion. The medical provider stated the cervical spine disorder is directly and causally related to architectural changes of the lumbar and thoracic spine. In a December 2017 VA treatment record, the Veteran complained of chronic pain. The medical provider stated that the Veteran received epidural corticosteroid injections in the neck in the 1980s or 1990s. The medical provider also stated that it seems the Veteran was involved in moving vehicle crash in the 1980s which resulted in neck pain. The medical provider stated the Veteran was treated by a non-VA chiropractor years ago for the same motor vehicle crash in the 1980s. On the February 2020 VA neck examination, the examiner found that the Veteran has a diagnosis of degenerative arthritis of the spine and cervical spondylosis. The Veteran stated the neck disorder began in 1969 when he fell from stairs and hit the deck. The Veteran stated he experienced sharp pain in the neck and shoulders and had a stiff neck. The Veteran stated he was treated with three days rest. The Veteran stated he currently experiences limited rotation of the neck, dizziness when rotating his head, shooting pain from the head to shoulders, and numbness in the fingers. The February 2020 VA examiner opined that the Veteran's neck disorder is less likely than not caused by service. The examiner reasoned that although the Veteran experienced a February 1970 fall in which he sustained injury to his knees, wrists, back, ankles, and hips, the examiner was unable to find evidence in the STRs or private treatment records that the Veteran continuously complained of or sought treatment for his cervical spine disorder from 1970 to 2015. The examiner stated that the lack of continuity of complaints and seeking treatment for over 45 years does not suggest a connection between the Veteran's current cervical spine disorder and the in-service injury. The February 2020 VA examiner also opined that the Veteran's cervical spine disorder is less likely than not proximately due to or the result of the Veteran's service-connected right knee disorder. The examiner reasoned that although the Veteran experienced an in-service February 1970 fall, the examiner is unable to find evidence in the Veteran's STRs or private treatment records that the Veteran continuously complained of or sought treatment for a cervical spine disorder form 1970 to 2015. Further, the examiner stated that the Veteran's neck and right knee are in different anatomical locations, the right knee disorder cannot directly cause or aggravate DJD or spondylosis of the cervical spine The May 2021 VA neck examiner indicated the Veteran has a diagnosis of degenerative arthritis in the cervical spine. The Veteran experiences stiffness, pain, headaches, and dizziness. The examiner opined that the Veteran's cervical spine disorder is less likely than not caused or aggravated by service-connected right knee disorder. The examiner reasoned that the Veteran's neck disorder is most likely caused by morbid obesity, prior occupation in construction, age, and genetics. The examiner stated that the Veteran's disc degeneration and accompanying arthritis is a common development. The examiner stated that age related changes are present in 40 percent of adults over 35 years and in almost all individuals over age 50. The examiner concluded that the Veteran's neck disorder is a stand-alone entity, neither adjunct to, nor aggravated by military service. Based on the record, the Board finds the preponderance of the evidence is in favor of the Veteran's claim. The Board finds inadequacies in the VA examinations and opinions. First, the February 2015 private examination did adequately explain how the now service-connected low back disorder caused or aggravated the neck disorder. Secondly, the Board finds that the February 2020 VA, May 2021, and June 2021 VA examiners did not address how the Veteran's altered gait and shifting weight impacted the Veteran's spine or how the low back disorder causes or aggravates the Veteran's neck disorder. Accordingly, the Board finds that the evidence for the claim of entitlement to service connection for a neck disorder is more persuasive. Therefore, reasonable doubt must be resolved in favor of the Veteran, and entitlement to service connection for a neck disorder is warranted. 38 U.S.C. § 5107(b); Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 7. Entitlement to service connection for left lower leg sciatica, as secondary to service-connected low back disorder, is granted. The Veteran asserts that he is entitled to service connection for left lower leg sciatica on a direct basis and secondary basis. As outlined below, the preponderance of the evidence of record demonstrates that the Veteran's left lower leg sciatica is caused or aggravated by service-connected low back disorder. As such, service connection is established on a secondary basis. The July 1970 STR separation examination shows the Veteran's lower extremities and spine to be normal. In an August 2013 VA treatment record, the medical provider indicated the Veteran has a history of peripheral neuropathy due to diabetes. The February 2015 private medical opinion stated the Veteran's left sciatic radicular pain is more likely than not directly and causally related to the Veteran's low back disorder. Accordingly, the medical provider stated it is more likely than not that the same is directly and causally related to the Veteran's military service. In a May 2019 VA treatment record, the Veteran complained of back pain that radiates down the left leg at times. He stated this has been chronic. On the February 2020 VA peripheral neuropathy examination, the examiner indicated the Veteran has a diagnosis of left sciatica. The Veteran stated the left sciatica began in approximately 1970 when he fell downstairs on a ship. He stated he experienced tingling, numbness, and sharp pain. The Veteran stated his symptoms have worsened over time. He stated he currently experiences tingling, numbness, and sharp pain. The examiner opined that the Veteran's left sciatica is less likely than not caused by service. The examiner stated although the Veteran experienced a fall in service, there is no evidence in the STRs or private treatment records showing the Veteran continuously complained of or sought treatment for his left sciatica from 1970 to 2015. The examiner stated that the lack of continuity of complains and seeking treatment for over 45 years does not suggests a connection between his current left sciatica with his in-service injury. The February 2020 VA examiner also opined that the Veteran's left sciatica is less likely than not proximately due to or the result of the Veteran's service-connected right knee disorder. The examiner reasoned that although the Veteran experienced a fall in February 1970, the examiner is unable to find evidence in the Veteran's STRs or private treatment records that the Veteran continuously complained or sought treatment for his left sciatic from 1970 to 2015. The examiner stated the Veteran's left sciatica is related to his low back disorder due to irritation or compression of certain nerves. Finally, the examiner stated that the Veteran's low back disorder and right knee disorder are in different anatomical locations; therefore the right knee disorder cannot directly cause or aggravate low back pain or associated left sciatica. The May 2021 VA peripheral nerve examiner indicated the Veteran has a diagnosis of left leg sciatica. The May 2021 examiner opined that it is less likely than not that the Veteran's bilateral lower leg sciatica is the result of or aggravated by service-connected right knee disorder. The examiner reasoned that the bilateral lower leg sciatica is most likely multifactorial from diabetes mellitus, type II, with diabetic neuropathy and severe low back DDD. The examiner stated there is no leg length discrepancy; however, there is antalgic gait, but no altered gait mechanics. Based on the record, the Board finds the preponderance of the evidence is in favor of the Veteran's claim. The Board finds that the February 2015 private medical opinion, February 2020 VA medical opinion, and May 2021 VA medical opinion all find that the Veteran's left leg sciatica is caused or aggravated by the Veteran's now service-connected low back disorder. Accordingly, the Board finds that the evidence for the claim of entitlement to service connection for a left lower leg sciatica is most persuasive. Therefore, the Board finds that the Veteran's left lower leg sciatica was caused or aggravated by service-connected low back disorder. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.310. Therefore, service connection for left lower leg sciatica is warranted. REASONS FOR REMAND In the February 2020 application for a TDIU, the Veteran claimed it is his psychiatric disability which prevents him from securing any substantially gainful occupation. The claims of entitlement to service connection for left knee, right and left hip, cervical spine, lumbar spine, and left sciatica disorders are herein granted and now await the RO's implementation of those grants and assignment of disability ratings. The Board finds it would be premature to rule on the TDIU claim while the effectuation of these grants remains pending. Two issues are inextricably intertwined when they are so closely tied together that a final decision on one issue cannot be rendered until a decision on the other issue has been rendered. Because the implementation of the grants of service connection for knee, hip, sciatic, and spine disabilities could significantly impact a decision on the issue of TDIU, the issues are inextricably intertwined. Harris v. Derwinski, 1 Vet. App. 180 (1991). Remand of the inextricably intertwined TDIU claim is therefore required. The matters are REMANDED for the following action: 1. Issue rating decisions effectuating the grants discussed above. 2. Thereafter, readjudicate the Veteran's claim for entitlement to a TDIU. Caroline B. Fleming Veterans Law Judge Board of Veterans' Appeals Attorney for the Board M. Thompson, Associate Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.