Citation Nr: 21027888 Decision Date: 05/07/21 Archive Date: 05/07/21 DOCKET NO. 19-27 886 DATE: May 7, 2021 ORDER 1. Entitlement to service connection for right ear hearing loss is denied. 2. Entitlement to service connection for tinnitus, to include as secondary to right ear hearing loss, is denied. 3. Entitlement to service connection for a right knee disability is denied. FINDINGS OF FACT 1. A right ear hearing loss disability was not manifested during the Veteran's service, or to a compensable degree within a year following his discharge from service, and such disability is not shown to be etiologically related to his service. 2. The preponderance of the evidence is against finding that the Veteran's current tinnitus began during active service, was manifested to a compensable degree within one year following the date of service separation, or is otherwise etiologically related to an injury or disease in service; continuity of tinnitus symptomatology is not shown; and his tinnitus is not shown to be secondary to (caused or aggravated by) a right ear hearing loss disability. 3. Any right knee injury in service was acute and resolved without residual pathology; a chronic right knee disability was not manifested in service; and the Veteran's current right knee disability is not shown to be etiologically related to his service/injury therein. CONCLUSIONS OF LAW 1. Service connection for a right ear hearing loss disability is not warranted. 38 U.S.C. §§ 1110, 1112, 5107; 38 C.F.R. §§ 3.303, 3.304, 3.307, 3.309, 3.385. 2. Service connection for tinnitus, including as secondary to right ear hearing loss, is not warranted. 38 U.S.C. §§ 1101, 1110, 1112, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309(a), 3.310. 3. Service connection for a right knee disability is not warranted. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.304. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The appellant is a Veteran who served on active duty from August 1964 to August 1967. These matters are before the Board of Veterans' Appeals (Board) on appeal from a December 2018 Department of Veterans Affairs (VA) rating decision. In January 2020 and October 2020 the matters were remanded for development. Service Connection Service connection may be granted for disability due to disease or injury incurred in or aggravated by active military service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303. Service connection may be granted for a disease initially diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38. C.F.R. § 3.303(d). To substantiate a claim of service connection, there must be evidence of: (1) a current claimed disability; (2) incurrence or aggravation of a disease or injury in service; and (3) a nexus between the disease or injury in service and the current disability. See Shedden v. Principi, 281 F.3d 1163, 1166-67 (Fed. Cir. 2004). The determination as to whether these requirements are met is based on an analysis of all the evidence of record and an evaluation of its credibility and probative value. Baldwin v. West, 13 Vet. App. 1 (1999); 38 C.F.R. § 3.303(a). Certain chronic diseases (to include sensorineural hearing loss (SNHL) and tinnitus as organic diseases of the nervous system) may be presumed to be service-connected, if manifested to a compensable degree within a specified period postservice (one year for organic diseases of the nervous system). 38 U.S.C. § 1112; 38 C.F.R. §§ 3.307, 3.309. For diseases listed in 38 C.F.R. § 3.309(a), nexus to service may be established by showing continuity of symptomatology. Walker v. Shinseki, 708 F.3d 1331, 1338-40 (Fed. Cir. 2013). For VA compensation purposes, hearing impairment is considered a disability when the auditory threshold in any of the frequencies 500, 1000, 2000, 3000, 4000 Hertz (Hz) is 40 decibels (dB) or greater; or when the auditory thresholds for at least three of the frequencies 500, 1000, 2000, 3000, or 4000 Hz are 26 dB or greater; or when speech recognition scores using the Maryland CNC Test are less than 94 percent. 38 C.F.R. § 3.385. Secondary service connection may be established for a disability that is proximately due to, or the result of, or aggravated by a service-connected disease or injury. Establishing secondary service connection requires evidence of: (1) a current disability (for which secondary service connection is sought); (2) an already service-connected disability; and (3) that the claimed disability was either caused or aggravated by the already service-connected disability. 38 C.F.R. § 3.310(a); see also Allen v. Brown, 7 Vet. App. 439 (1995). Lay evidence is competent if it is provided by a person who has knowledge of facts or circumstances and conveys matters that can be observed and described by a layperson. 38 C.F.R. § 3.159(a)(2). Competent medical evidence is necessary where the determinative question requires medical knowledge. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). Competent medical evidence means evidence provided by a person who is qualified through education, training, or experience to offer medical diagnoses, statements, or opinions. Competent medical evidence may also mean statements conveying sound medical principles found in medical treatises. Competent medical evidence may also include statements contained in authoritative writings, such as medical and scientific articles and research reports or analyses. 38 C.F.R. § 3.159(a)(1). When there is an approximate balance of positive and negative evidence regarding the merits of an issue material to the determination of a 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. A claim will be denied only if the preponderance of the evidence is against the claim. See 38 U.S.C. § 5107; 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 56 (1990). 1. Entitlement to service connection for right ear hearing loss. The Veteran's military occupational specialty (MOS) was inventory management specialist. He attributes his current right ear hearing loss to exposure to loud noise in service from working near the flight line. It may reasonably be conceded that he was exposed to noise trauma in service. The Veteran's service treatment records (STRs) are silent regarding a right ear hearing loss disability. On July 1964 service entrance examination, audiometry showed that puretone thresholds for the right ear, in decibels, were: HERTZ 500 1000 2000 3000 4000 RIGHT 5 5 0 -5 -5 After conversion from ASA to ISO-ANSI standards/units, the puretone thresholds for the right ear were: HERTZ 500 1000 2000 3000 4000 RIGHT 20 15 10 5 0 In a contemporaneous report of medical history, he denied ear trouble or running ears. On July 1967 service separation examination, audiometry showed that puretone thresholds for the right ear were: HERTZ 500 1000 2000 3000 4000 RIGHT 0 0 5 0 5 After conversion from ASA to ISO-ANSI standards/units, the puretone thresholds for the right ear were: HERTZ 500 1000 2000 3000 4000 RIGHT 15 10 15 10 10 In a contemporaneous report of medical history, he denied ear trouble or running ears. On October 2018 Hearing Loss and Tinnitus Disability Benefits Questionnaire (DBQ), audiometry puretone thresholds for the right ear were: HERTZ 500 1000 2000 3000 4000 RIGHT 30 30 25 35 40 Speech discrimination testing revealed that right ear speech discrimination was 94 percent correct. The Veteran reported that he worked near the flight line in his MOS. (The audiologist noted "not sure" on use of hearing protection devices.) He denied occupational and recreational noise exposure (not specified whether it was preservice or postservice). The audiologist opined that the right ear hearing loss is not at least as likely as not caused by or a result of an event in military service. She noted that the Veteran's right ear hearing was within normal limits at separation from service (and therefore his current right ear hearing loss began after discharge). She cited to the 2005 Institute of Medicine Study (IOM) "Noise and Military Service: Implications for Hearing Loss and Tinnitus" (stating that "There is not sufficient evidence from longitudinal studies in laboratory animals or humans to determine whether permanent noise-induced hearing loss can develop much later in one's lifetime, long after the cessation of that noise exposure. Although the definitive studies to address this issue have not been performed, based on anatomical and physiological data available on the recovery process following noise exposure, it is unlikely that such delayed effects occur") to support her negative nexus opinion (to service). She further stated that based on the objective evidence (audiograms), there was no evidence on which to conclude that the right ear hearing loss was caused by or a result of the Veteran's military service, including noise exposure. The Board's January 2020 remand found the October 2018 audiologist's opinion inadequate for rating purposes because it discussed the 2005 IOM study without addressing another (contradictory) finding ("Based on current knowledge of cochlear physiology there was no sufficient scientific basis for the existence of delayed-onset hearing loss.") The remand requested the examiner to state why the contradictory aspects of the IOM study apply to this particular Veteran. In a March 2020 Medical Opinion based on review of the record, the consulting audiologist noted normal right ear hearing from entrance to discharge and noise exposure is conceded for the Veteran. He stated that medical research did not support delayed onset hearing loss from noise exposure and that the Veteran's right ear hearing loss showed a flat mild hearing loss (which is consistent with presbycusis and not consistent with noise induced hearing loss). (Noise induced hearing loss shows normal/mild low frequency hearing loss with more significant (usually moderate or more) high frequency dip in hearing.) He opined that since the audiograms during service showed no significant changes/no hearing loss, the current right ear hearing loss is less likely than not due to military service. Regarding the contradictory findings in the 2005 IOM study, the audiologist stated that "the contradiction reported is that there is not sufficient evidence to show that delayed effects can occur". He stated that the cited study explained that there is no research available to show that delayed effects of hearing loss (or tinnitus) can occur years after noise exposure has ended. The study is relevant to the Veteran due to normal hearing and no significant hearing changes at separation. He identified presbycusis (widely known to be the most common cause of hearing loss) as an alternative etiology for the current right ear hearing loss and used the following research articles to support his rationale: 1) 2017 Article: Current insights in noise-induced hearing loss (a literature review of the underlying mechanism, pathophysiology, asymmetry, and management options), 2) 2015 Article: Noise-Induced Neural Degeneration and Therapeutic Effect of Antioxidant Drugs, and 3) 2006 Article: Acceleration of Age-Related Hearing Loss by Early Noise Exposure Evidence of a Misspent Youth. These articles concluded that early exposure to noise can cause an increase in the likelihood of age-related hearing loss (but do not support delayed onset hearing loss (or tinnitus) from noise exposure alone). The Board's October 2020 remand requested additional clarification on the service audiograms (i.e. converting audiometric testing data from ASA to ISO units) and instructed the examiner to convert the data obtained during July 1964 and July 1967 audiometric testing from ASA to ISO units and address the significance of the 5-decibel increase at 2000 Hz and 3000 Hz and the 10-decibel increase at 4000 Hz between service entrance and separation when providing an etiology opinion for the right ear hearing loss. In a January 2021 Medical Opinion DBQ based on review of the record, the consulting otolaryngologist stated that an ASA to ANSI/ISO conversion was a moot point (but nonetheless converted the July 1964 and July 1967 audiometric testing from ASA to ISO units) because changes in thresholds matter as opposed to absolute numbers (when determining the severity of hearing loss). (Evaluation of the Veteran's enlistment and separation examinations showed no significant shifts in his right ear hearing.) He explained that 15 dB shift is used as the cut off for significance because there can be a 10 dB shift (worse or better) as part of normal INTERtest variability. (This means a test today and tomorrow can shift 10 dB without any changes in hearing.) The Veteran had a 10 dB shift at 4K in the right ear and 5 dB at 3K (but he also improved by 10 dB at 4K in the left ear), which showed normal INTERtest variability, so there was no evidence of any acoustic trauma taking place in service. The otolaryngologist opined it is less likely than not that the right ear hearing loss had its onset or is otherwise related to active service including the conceded noise exposure. At the outset, the Board finds that the March 2020 and January 2021 advisory medical opinions are cumulatively substantially compliant with the Board's remand instructions and that the evidence is now adequate for rating purposes. As it is established that the Veteran has a current diagnosis of right ear hearing loss disability and that he was exposed to loud noise in service, what remains necessary to substantiate this claim is competent evidence that the hearing loss is etiologically related to his service/noise trauma therein. See Shedden, 381 F.3d at 1167. The evidence does not show, and it is not alleged, that a right ear hearing loss disability was manifested in service. The Veteran's STRs, including his July 1967 service separation examination report, are silent for complaints, treatment, findings, or diagnosis pertaining to hearing loss. Likewise, a right ear hearing loss disability is not shown to have been manifested within a year following the Veteran's separation from service, nor is postservice continuity of sensorineural hearing loss shown. While the Veteran may be competent to report a perception of a reduction of hearing acuity, he is not competent to establish by his accounts of remote perceptions that he has had continuity of a hearing loss disability since service; under governing regulation (38 C.F.R. § 3.385) hearing loss disability must be established by specified audiometry. Right ear hearing loss was initially diagnosed by such audiometry in October 2018 (51 years after the Veteran's separation from service). Accordingly, service connection for right ear hearing loss based on continuity under 38 C.F.R. § 3.303(b) is not warranted. In the absence of evidence of onset in service and continuity since, whether a current right ear hearing loss disability may be related to remote service/events therein is a medical question beyond the realm of common knowledge, and incapable of resolution by lay observation. See Jandreau, 492 F.3d at 1377. It requires medical expertise. The Veteran is a layperson, and his own opinion is not competent evidence in the matter. [The Board notes that the October 2018 VA medical opinion was inadequate for rating purposes because it did not address the contradictory aspects of the 2005 IOM study and relied on normal right ear hearing at separation for establishing a negative nexus opinion (to service) (i.e. absence of a hearing loss in service may not be the sole basis for a finding that a hearing loss disability is not service-connected). Its conclusion is not probative evidence in this matter.] The only competent and fully adequate medical opinions in this matter are found in the March 2020 DBQ (in conjunction with the January 2021 advisory medical opinion). The March 2020 consulting audiologist and January 2021 consulting otolaryngologist opined that the current right ear hearing loss is less likely than not due to military service. Both providers applied their medical expertise to the specific circumstances in this case, cited to supporting medical principles/medical literature (the March 2020 audiologist discussed the hearing loss configuration (noting it was consistent with hearing loss due to presbycusis, but not with hearing loss due to noise trauma) and cited to supporting research articles from 2017, 2015, and 2006; the January 2021 otolaryngologist used the INTERtest variability), and included adequate rationale for the conclusion reached. The March 2020 audiologist noted that the articles concluded that early exposure to noise can cause an increase in the likelihood of age-related hearing loss (but do not support delayed onset hearing loss (or tinnitus) from noise exposure alone). He identified presbycusis (widely known to be the most common cause of hearing loss) as an alternative etiology for the current right ear hearing loss. The January 2021 otolaryngologist further reinforced the March 2020 audiologist's negative nexus opinion (to service) by explaining that the audiometric testing data showed normal INTERtest variability, so there was no evidence of any acoustic trauma injury taking place in service. The Veteran has not presented an adequate (equally or more probative) medical opinion or medical treatise evidence to the contrary. Considering the foregoing, the preponderance of the evidence is against the claim of service connection for right ear hearing loss. Accordingly, the appeal in this matter must be denied. 2. Entitlement to service connection for tinnitus, to include as secondary to right ear hearing loss. The Veteran's primary theory of entitlement to the benefit sought is one of direct service connection; he asserts that his tinnitus is a direct link to military service. See January 2019 Notice of Disagreement (NOD). As noted above, it may reasonably be conceded that he was exposed to noise trauma in service. The Veteran's STRs are silent for complaints, treatment, or diagnosis, of tinnitus. On October 2018 Hearing Loss and Tinnitus DBQ, the Veteran reported recurrent tinnitus and that it happened "sometimes" and onset was "a long time ago" (he could not describe the onset or circumstances of the tinnitus). The audiologist noted that the Veteran had multiple medical problems (He said he was "messed up," took a number of medications, tinnitus was worse when his blood pressure was high and was not sure if his blood pressure or diabetes were under control). Since there was a lack of evidence (i.e. details on circumstances and onset of the tinnitus) and the presence of many medical conditions and medications, she opined that it is less likely that his tinnitus was caused by military noise exposure. She cited to National Institute of Deafness and other Communication Disorders (stating that doctors/scientists have discovered that people with different kinds of hearing loss also have tinnitus and there are more than 200 medicines and countless natural foods and elements that can cause tinnitus. Allergies, tumors, problems in the heart/blood vessels, jaw, dentition, and the neck can cause tinnitus.) to support her negative nexus opinion (to service). The Board's January 2020 remand found that the October 2018 medical opinion raised an alternative theory of entitlement (i.e. secondary service connection) when it stated that "people with different kinds of hearing loss also have tinnitus." As such, the Board requested a medical opinion on whether the tinnitus was either caused or aggravated by the hearing loss. In a March 2020 Medical Opinion DBQ based on review of the record, the consulting audiologist opined that his tinnitus is less likely than not due to his military service. He cited to an absence of complaints, treatment, or diagnosis, of tinnitus in service and stated that the Veteran could not recall when it started or if there was a specific incident that caused it. He concluded that without a conclusive onset of the symptoms during service, there was no way to link his service to his onset of tinnitus. (Tinnitus is a subjective complaint and no objective measure exists to verify the presence or absence of tinnitus. The etiology of tinnitus cannot be determined using current clinical technologies. Etiology is typically inferred by patient history and a review of medical records.) He further stated that the Veteran had hearing loss in both ears and his tinnitus is likely a symptom of his hearing loss. The Board's October 2020 remand found the March 2020 medical opinion to be nonresponsive to the January 2020 remand with regard to a discussion of secondary service connection. As such, the October 2020 remand requested a medical opinion to address the secondary service connection for tinnitus. In a January 2021 Medical Opinion DBQ based on review of the record, the consulting otolaryngologist opined that since there was no evidence of acoustic trauma, it is less likely than not that his tinnitus is related to his service and any conceded noise exposure. He cited to an absence of complaints of tinnitus in service and noted that the Veteran did not claim the tinnitus began in service. The Veteran reported that his tinnitus was worse when his blood pressure was elevated. The otolaryngologist identified pulsatile tinnitus (related to uncontrolled medical issues as opposed to noise exposure) as an alternative etiology. Regarding secondary service connection theory of entitlement, the otolaryngologist opined that since tinnitus is not caused by hearing loss, it is less likely than not that it is due or aggravated by his right ear hearing loss. He stated that the tinnitus occurred when he had uncontrolled blood pressure (i.e., had the tinnitus been a result of hearing loss, it should be present all the time without impact from his blood pressure. The fact that it is intermittent and associated with blood pressure means it is not caused [or aggravated] by hearing loss.) As it is established that the Veteran has a current diagnosis of tinnitus and that he was exposed to loud noise in service, what remains necessary to substantiate this claim is competent evidence that the tinnitus is etiologically related to his service/noise trauma therein. See Shedden, 381 F.3d at 1167. The evidence does not show, and it has not been alleged, that tinnitus was manifested in service. The Veteran's STRs are silent for complaints, treatment, or diagnosis, of tinnitus. His tinnitus is not shown to have been manifested within a year following his separation from service, and postservice continuity of tinnitus is not shown. On October 2018 DBQ, the Veteran reported recurrent tinnitus happened "sometimes" and onset was "a long time ago" and on January 2021 DBQ, he stated that the tinnitus did not begin in service. October 2018 was the first time when he reported tinnitus, which is 51 years after his separation from service. (There are no documented reports of tinnitus during the interval between service separation and October 2018.) As tinnitus is a disability that is diagnosed based on self-reports (by the person experiencing it) and generally is incapable of objective verification, the Veteran is competent to establish by his own accounts that he has tinnitus. The Board has no reason to question his tinnitus started "a long time ago" and has had it continuously since. Rather, the Board finds that service connection for tinnitus based on continuity of symptomatology is not demonstrated by the evidence in the record. The analysis turns to review of the competent (medical, as the etiology of tinnitus/whether it may be related to remote exposure to noise is a medical question) evidence in the record (whether it otherwise shows a nexus between the tinnitus and service). The October 2018 medical opinion and March 2020/January 2021 advisory medical opinions are the only medical evidence in the record that address that question, and they are all against the Veteran's claim. The October 2018/March 2020 VA audiologists and January 2021 VA otolaryngologist cited to an absence of complaints, treatment, or diagnosis, of tinnitus in service, as well as the Veteran's uncertainty when the tinnitus began, and opined that his tinnitus is less likely than not due to his military service. The examiners included a clear explanation of rationale, citing to clinical data/medical principles (lack of evidence regarding circumstances and onset of the tinnitus, presence of many medical conditions and medications potentially causing his tinnitus, and no evidence of acoustic trauma in service) and medical literature (National Institute of Deafness and other Communication Disorders), and identifying an alternative nonservice-related etiology (pulsatile tinnitus, which is related to uncontrolled medical issues as opposed to noise exposure). The Veteran has not submitted any medical opinion to the contrary. The analysis proceeds to whether the tinnitus is, as was alleged, secondary to a right ear hearing loss. It is not in dispute that he has tinnitus (as it is diagnosed based on self-reports). However, as service connection for a right ear hearing loss disability has been denied, another threshold requirement for substantiating a secondary service connection is not met, and the claim of service connection for tinnitus as secondary to a right ear hearing loss disability lacks legal merit. 38 C.F.R. § 3.310(a); Sabonis v. Brown, 6 Vet. App. 430 (1994). As the preponderance of the evidence is against the Veteran's claim of service connection for tinnitus under any applicable theory of entitlement, the benefit-of-the-doubt standard of proof does not apply; the appeal in the matter must be denied. 38 U.S.C. § 5107(b). 3. Entitlement to service connection for a right knee disability. The Veteran asserts that he injured his right knee when he fell down a hill during service and the condition worsened due to injuries sustained in May 1972 and June 1974 (postservice) car accidents. An April 11, 1966 STR notes that he sought treatment for right knee pain after sustaining an injury in a fall. On July 1967 service separation examination, his right knee was normal on clinical evaluation. In August 1979, VA received accident reports showing automobile accidents on May 7, 1972 and June 2, 1974. In a July 1974 private treatment record, the examiner noted the Veteran had an automobile accident on June 2, 1974. (His car was struck in the rear on the left side by another car that had failed to stop at a red light.) The accident injured his entire left side and he was rendered unconscious for a few seconds. In the Emergency Room, the Veteran complained of headache, dizziness, and pain (in neck, low back, left elbow, knee, hip, and shoulder). X-rays of his lumbosacral spine, left shoulder, left hip, left knee and left foot were negative for fracture or dislocation. The examiner found that he sustained cerebral concussion, sprain of cervical and lumbar spine, and multiple soft tissue injuries. In an October 1974 private treatment record, it was noted the Veteran reported severe pain in his neck and back and occasional pain in his knee in the early morning hours. On May 2019 Knee and Lower Leg Conditions DBQ, the examiner noted a diagnosis of right knee strain. The Veteran reported that he fell down a hill while serving in Spain and that his right knee condition was worsened by injury in multiple car accidents postservice. No treatment, medications, or surgery for a right knee condition were reported. No X-rays, labs, testing were reported. In a May 2019 Medical Opinion DBQ, the examiner opined that the right knee strain was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. She stated that the Veteran sought medical treatment only one time on April 11, 1966 for right knee pain due to a twisting injury running and returned to duty that same day. She cited to an absence of evidence of chronic knee pain afterwards (i.e. no documented chronicity for the condition in relation to the in-service complaints). In a December 2020 Medical Opinion DBQ based on review of the record, the physician noted that the Veteran had an acute self-limited event on April 11, 1966 and served an additional year without further complaints. He cited to an absence of a chronic knee condition in service and that a July 1967 separation exam was negative for trick knee. (There was also no chronic knee condition at any time proximate to service. Four decades following service separation passed, and there was no evidence of a chronic knee condition during that time frame.) (Upon his review of the July 1974/October 1974 physician letters (pertaining to the June 1974 car accident), he noted that there was no documentation of medical treatment for a right knee condition at that point (7 years postservice) and the car accident represented a new event, further eliminating service events as a possible nexus.) Separation exams were notably thorough, especially with respect to joints (so it is unlikely a significant knee condition would have been missed or unreported). There was no evidence that the Veteran sought medical treatment for his knee until 2019 (when he filed the disability claim). He expressed a belief that the 2019 VA examiner erred in not obtaining imaging because it more likely than not would have shown bilateral degenerative joint disease (DJD) (and a DJD diagnosis would supersede the diagnosis of right knee strain). Since there was no evidence of a chronic right knee condition in service, at separation or proximate to service (despite the Veteran's claims to the contrary), he opined that it is less likely than not that his right knee strain (diagnosed in the absence of imaging) is due to or incurred in events in service, including the April 11, 1966 fall and that the medical evidence did not support continuity since service. (He further stated that this opinion would also apply to DJD (if it becomes diagnosed) and that his confidence level was greater than 99%.) It is not in dispute that the Veteran has a right knee disability (as a right knee strain was diagnosed in May 2019). As the December 2020 examiner stated, he had an "acute self-limited event on April 11, 1966 and served an additional year without further complaints". The Board finds that the overall evidence shows that the right knee injury the Veteran sustained in service was acute and resolved. Consequently, service connection for a current right knee disability on the basis that it became manifest in service and has persisted since is not warranted. What remains for consideration is whether a right knee disability is otherwise shown to be etiologically related to the Veteran's service. Whether in the absence of a finding of continuity, as here, a right knee disability may be related to remote service is a medical question not capable of resolution by mere lay observation; it requires medical expertise. See Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). The only medical evidence in the record that directly addresses that question is in the opinions offered on the May 2019 and December 2020 DBQs, and is against the Veteran's claim. The examiners cited to supporting factual data and noted that the STRs showed a single acute self-limited event on April 11, 1966 (and he served an additional year without further complaints), that there was no evidence of a chronic knee condition in service, at separation or proximate to service, and that there were no postservice treatment records that show treatment for [residuals of] a right knee injury. In fact, the December 2020 examiner pointed out that the current right knee disability was first documented in 2019 (when the Veteran filed the service-connection claim), which is 52 years after separation. He explained that since the separation examination was thorough, a significant knee condition [if found] would have been reported. He also noted that contrary to the Veteran's claims, the record does not show he received treatment for his knee following the 1972 and 1974 car accidents [which supports that he did not then have a chronic right knee disability on which further disability was superimposed by trauma from those accidents. The May 2019 and December 2020 advisory medical opinions reflect the examiners' familiarity with the entire record and include rationale that cites to specific supporting clinical data, and the Board finds find them to be highly probative evidence in this matter. In the absence of competent evidence to the contrary, the Board finds them persuasive. The Board acknowledges the Veteran's belief that his right knee disability is related to his service. However, as noted above, the etiology of his current right knee disability, whether it is related to an acute injury in service that resolved quickly without residuals, is a medical question. Because he is a layperson, and does not cite to supporting medical (opinion or treatise) evidence, his opinion has no probative value in the matter. Considering the foregoing, the Board finds that the preponderance of the evidence is against the claim of service connection for a right knee disability. Therefore, the benefit of the doubt rule does not apply. The appeal must be denied. GEORGE R. SENYK Veterans Law Judge Board of Veterans' Appeals Attorney for the Board D. Chu, 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.