Citation Nr: 21008013 Decision Date: 02/11/21 Archive Date: 02/11/21 DOCKET NO. 10-25 758 DATE: February 11, 2021 ORDER Entitlement to service connection for chronic venous insufficiency of the right lower extremity, to include as secondary to service connected bilateral pes cavus is denied. Entitlement to service connection for a cervical spine disorder, to include as secondary to service connected bilateral pes cavus and lumbar spine disorder is denied. Entitlement to service connection for a right knee disorder, to include as secondary to service connected bilateral pes cavus is denied. Entitlement to service connection for diabetes mellitus, to include as secondary to trichloroethylene exposure is denied. FINDINGS OF FACT 1. The preponderance of the evidence does not support a finding that the Veteran’s chronic venous insufficiency of the right lower extremity is secondary to his service connected bilateral pes cavus, or is otherwise related to an in-service event, injury, or disease. 2. The preponderance of the evidence does not support a finding that the Veteran’s cervical spine disorder, is secondary to his service connected bilateral pes cavus and lumbar spine disorders, or is otherwise related to an in-service event, injury, or disease. Arthritis was first shown years after service. 3. The preponderance of the evidence does not support a finding that the Veteran’s right knee disorder is secondary to his service connected bilateral pes cavus, or is otherwise related to an in-service event, injury, or disease. Any arthritis was first shown years post-service. 4. The preponderance of the evidence does not support a finding that the Veteran’s diabetes mellitus is secondary to trichloroethylene exposure, or is otherwise related to an in-service event, injury, or disease. CONCLUSIONS OF LAW 1. The criteria for service connection for chronic venous insufficiency of the right lower extremity, to include as secondary to service connected bilateral pes are not met. 38 U.S.C. §§ 1101, 1110, 1131; 38 C.F.R. §§ 3.303, 3.304, 3.310. 2. The criteria for service connection for a cervical spine disorder, to include as secondary to service connected bilateral pes cavus and lumbar spine disorders are not met. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.303, 3.307, 3.309, 3.310. 3. The criteria for service connection for a right knee disorder, to include as secondary to service connected bilateral pes cavus are not met. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.303, 3.307, 3.309, 3.310. 4. The criteria for service connection for diabetes mellitus, to include as secondary to trichloroethylene exposure are not met. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.303, 3.307, 3.309, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran had a period of active duty service from February 1969 to April 1976 and from July 1981 to December 1984. In February 2019, the Board remanded the Veteran’s claims for additional development. The Board finds that there was substantial compliance with the remand directives for the issues on appeal as discussed below. See Stegall v. West, 11 Vet. App. 268, 271 (1998). Service Connection Service connection may be granted for a disability resulting from a disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303. To establish a right to compensation for a present disability, a Veteran must show: “(1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service”—the so-called “nexus requirement.” Holton v. Shinseki 557 F.3d 1362, 1366 (Fed. Cir. 2010) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004)). Except as otherwise provided by law, a claimant has the responsibility to present and support a claim for benefits. VA shall consider all information lay and medical evidence of record in a case and when there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, VA shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107 (2012); 38 C.F.R. § 3.102 (2019); Gilbert v. Derwinski, 1 Vet. App. 49, 53 (1990). To deny a claim on its merits, a preponderance of the evidence must be against the claim. Alemany v. Brown, 9 Vet. App. 518, 519 (1996). For Veterans with 90 days or more of active service during a war period or after December 31, 1946, certain chronic diseases may be presumed to have been incurred in service if they manifest to a compensable degree within one year of separation from service. 38 U.S.C. §§ 1112, 1113, 1137 (2012); 38 C.F.R. §§ 3.307, 3.309 (2020). Arthritis and diabetes mellitus are on the list of diseases presumed to have been incurred in-service and receive a one-year presumption. Service connection may also be granted for a disability that is proximately due to, the result of, or aggravated by a service-connected disability. 38 C.F.R. § 3.310. In such an instance, the Veteran may be compensated for the degree of disability over and above the degree of disability existing prior to the aggravation. 38 C.F.R. § 3.310 (b); see Allen v. Brown, 7 Vet. App. 439, 448 (1995). 1. Entitlement to service connection for chronic venous insufficiency of the lower right extremity, to include as secondary to service connected bilateral pes cavus. Service treatment records (STRS) reveal that the Veteran underwent an osteotomy procedure of his fourth and fifth metatarsals on September 1984 for bilateral pes planus. Due to the severity of the Veteran’s bilateral pes planus, he was medically discharged from military service. STRs do not reveal any complaints diagnosis or treatments for circulatory problems of the lower right extremity. At an examination prior to separation, the Veteran’s circulatory system was noted as normal with no findings of blood flow problems to the right lower extremity diagnosed. In a December 1997 VA feet examination, the examiner diagnosed the Veteran with peripheral vascular disease of the right foot. The examiner opined that it is as likely as unlikely that the circulation in the Veteran’s right foot has been altered by his right foot surgery. The examiner explained that the Veteran’s right foot surgery is responsible for some circulation problems to the Veteran’s right foot, but not all circulation problems. In a March 1998 private treatment venous evaluation, the Veteran was diagnosed with severe venous reflux and insufficiency of both popliteal veins of the lower right extremity. April 1998 private treatment records reveal that the Veteran denied any right lower extremity weakness. In a March 2000 VA examiner note, the examiner reported that the Veteran was being treated for long term venous insufficiency which has been an ongoing problem for a long time. In a May 2000 VA veins examination, the examiner diagnosed the Veteran with chronic venous insufficiency. The examiner opined that it is not likely that the Veteran’s service connected pes planus and reconstructed foot surgery caused the onset of his chronic venous insufficiency. In a June 2017 private examiner opinion, the examiner diagnosed the Veteran with chronic venous insufficiency of the lower right extremity. The examiner opined that it is as likely as not that the Veteran’s right foot surgery caused the onset of his circulation problems. The examiner explained that the Veteran’s December 1997 VA examination reported findings of poor circulation in the right foot as compared to adequate circulation in his left foot. The examiner explained that normally circulation problems that are obesity related would result in equal impairment of both feet. The examiner noted that the Veteran has undergone two surgeries on his right foot and that surgery by implication results in circulation damage. Thus, the Veteran’s residual circulation disorder of the right foot is related to his right foot surgeries. In a March 2018 VA vein conditions examination, the examiner diagnosed the Veteran with chronic venous insufficiency of the lower right extremity. The examiner opined that the Veteran’s chronic venous insufficiency is less likely than not due to or the result of the Veteran’s service connected bilateral pes cavus. The examiner explained that pes cavus and venous circulation of the legs are not anatomically related disorders. The examiner indicated that surgery of the right foot may affect circulation of the right foot locally, but based on anatomical considerations cannot affect circulation above the right foot. The examiner concluded that it is impossible for chronic venous insufficiency of the right leg to be related to the status post surgeries or to the Veteran’s service connected pes cavus. The examiner also noted that the Veteran has bilateral venous insufficiency rather than just right leg insufficiency which would also indicate no correlation between his right foot surgeries and his right leg venous insufficiency. The examiner opined that it is impossible for the Veteran’s right leg venous insufficiency to be aggravated beyond its natural progression by surgery of the right foot. In a February 2019 VA vein conditions examination, the examiner diagnosed the Veteran with chronic venous insufficiency of the right lower extremity. The examiner explained that he reviewed the conflicting evidence and determined that chronic venous insufficiency of the legs results from valvular dysfunction. There are many valves located in the venous system in the legs. When the valves do not close properly, blood has difficulty flowing against gravity from the legs to the heart. The examiner explained that damage to these valves can be a result of the following: trauma; blood clots; varicose veins; obesity; and smoking. The examiner also noted that there is alteration to the circulation in the Veteran’s right foot, as evidenced by the decreased dorsalis pedis pulse. However, this alteration has not damaged the veins in the legs and, as such, is not causing or aggravating the venous insufficiency above the foot. The examiner also opined that the Veteran’s bilateral pes cavus did not aggravate his chronic venous insufficiency. The Board acknowledges the conflicting medical opinions submitted by the Veteran which supports a finding that his chronic venous insufficiency disorder of the lower right extremity disorder is related to his service connected bilateral pes cavus. When evaluating medical opinions, it is the province of the Board to weigh the evidence and decide where to give credit and where to withhold the same, and in so doing, to also accept certain medical opinions over others. See Evans v. West, 12 Vet. App. 22, 30 (1999). The Board cannot make its own independent medical determinations, and there must be plausible reasons for favoring one opinion over another. See Colvin v. Derwinski, 1 Vet. App. 171 (1991). Generally, the degree of probative value which may be attributed to a medical opinion issued by a VA or private treatment provider takes into account such factors as its thoroughness and degree of detail and whether there was review of the Veteran’s claims file. Prejean v. West, 13 Vet. App. 444 (2000). An evaluation of the probative value of a medical opinion or diagnosis is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusions reached. See Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993). When confronted with conflicting medical opinions, the Board must weigh each and favor one competent medical expert over another if its statement of reasons and bases is adequate to support that decision. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). The Board must also determine which of the competing medical opinions is more probative of the medical question at issue. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300 (2008). The basis of the examiner’s opinion focused on the Veteran’s right foot surgeries as causing the onset of his chronic venous insufficiency of the lower right extremity. However, although some of the examiners mentioned the Veteran’s morbid obesity, they did not discuss the specific health impact caused by the Veteran’s obesity as related to the Veteran’s chronic venous insufficiency disorder of the lower right extremity disorder. While there is some evidence that the Veteran experienced some post-operative residuals from his right foot surgery, there is little persuasive evidence in the record to support a finding that the Veteran’s chronic venous insufficiency of the lower right extremity is proximately related to his service connected bilateral pes cavus. Moreover, the examiner did not address the conflicting examiner findings that surgery of the right foot may affect circulation of the right foot locally, but based on anatomical considerations cannot affect circulation above the right foot. Thus, the Board has determined that the thorough and extensive February 2019 VA examination findings are more probative and compelling to the medical issue at question. Therefore, the foregoing summary of the treatment record reveals no possibility for service connection for a chronic venous insufficiency disorder of the lower right extremity on a secondary basis. Although the Veteran contends that his reported chronic venous insufficiency disorder is related to his service connected bilateral pes cavus, there is no evidence in the record of treatment in-service for a chronic venous insufficiency. The Board does acknowledge that the Veteran experiences chronic venous insufficiency of the lower right extremity; however, there is not a significant correlation between the Veteran’s chronic venous insufficiency disorder and his time in-service as related to his service connected bilateral pes cavus. Moreover, since the July 2017 examiner findings, the Veteran has undergone several thorough and extensive VA vein conditions examinations which concluded that it is impossible for chronic venous insufficiency of the right leg to be related to the Veteran’s service connected pes cavus. The examiner explained that the Veteran has bilateral venous insufficiency rather than just right leg insufficiency which would also indicate no correlation between his right foot surgeries and his right leg venous insufficiency. Furthermore, the examiner explained that chronic venous insufficiency of the legs results from valvular dysfunction and there are many valves located in the venous system in the legs. The examiner noted that when the valves do not close properly, blood has difficulty flowing against gravity from the legs to the heart. The examiner explained that damage to these valves can be a result of the following: trauma; blood clots; varicose veins; obesity; and smoking. The examiner also explained that there is alteration to the circulation in the Veteran’s right foot, as evidenced by the decreased dorsalis pedis pulse. However, this alteration has not damaged the veins in the legs and, as such, is not causing or aggravating the venous insufficiency above the foot. As there is not a significant documented correlation between the Veteran’s right leg venous insufficiency disorder and his service connected bilateral pes cavus with bilateral pes planus, the Board finds that the Veteran’s right leg venous insufficiency disorder is less likely than not related to his service connected bilateral pes cavus. The Board also reviewed the Veteran’s lay statements asserting that the onset of his chronic venous insufficiency disorder of the lower right extremity was caused by his service connected bilateral pes cavus. Lay people are competent to report on matters observed or within their personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). Therefore, the Veteran is competent to provide statements of symptoms which are observable to his senses. However, the Board must emphasize that the Veteran is not competent to interpret accurately clinical findings pertaining to a chronic venous insufficiency disorder of the lower right extremity as this requires highly specialized knowledge and training. 38 C.F.R. § 3.159 (a)(1) (2018). See also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). As a pathology for the onset of a chronic venous insufficiency of the lower right extremity has not been shown to be related to the Veteran’s service-connected bilateral pes cavus, the Board concludes that the clinical evidence does not support the Veteran’s contentions for a granting of service connection on a secondary basis. Based on this evidence, the Board finds service connection is not warranted. The Board has considered the benefit-of-the-doubt doctrine; however, the Board does not perceive an approximate balance of positive and negative evidence. The preponderance of the evidence is against the claim, the doctrine is not applicable, and the claim must be denied. 38 U.S.C. § 5107 (b) (2012); 38 C.F.R. § 4.3 (2020). 2. Entitlement to service connection for a cervical spine disorder, to include as secondary to service connected bilateral pes cavus and lumbar spine disorders. STRs reveal that the Veteran underwent a osteotomy procedure of his fourth and fifth metatarsals on September 1984 for bilateral pes planus. Due to the severity of the Veteran’s bilateral pes planus, he was medically discharged from military service. A review of the Veteran’s STRS do not reveal any complaints diagnosis or treatments for a cervical spine disorder. At an examination prior to separation, the Veteran’s cervical spine was noted as normal with no findings of arthritis, bone, or joint deformities diagnosed. December and March 1998 VA outpatient treatment records reveals that the Veteran presented with chronic neck pain and was diagnosed with a herniated disc of the C6-C7. April 1998 private treatment records reveal that the Veteran presented with complaints of neck pain. The Veteran reported improved symptomology after he underwent corrective neck fusion surgery in January 1998. November 1999 VA treatment records reveal that the Veteran was diagnosed with pseudarthritis of the cervical spine and underwent a cervical spine fusion. December 1999 X-ray findings reveal anterior subluxation of the C4 and C5 with lower cervical degenerative changes. In a May 2000 VA spine examination, the examiner diagnosed the Veteran with pseudarthritis of the cervical spine at C6-C7. The examiner opined that it is not likely that the Veteran’s reconstructive foot surgery and pes cavus contributed to his cervical spine degenerative disc disease. Rather the examiner noted that the Veteran’s cervical spine disorder is related to other multifactorial causes. In a June 2017 private examiner opinion, the examiner diagnosed the Veteran with a cervical spine disorder and opined that the Veteran’s altered gait would not have caused the onset of his cervical spine disorder; however, the examiner opined that the Veteran’s lumbar spine problems caused the onset of his cervical spine disorder. The examiner opined that it is as likely as not that the Veteran’s foot disorder laid the foundation for the Veteran’s cervical spine disorder. In a March 2018 VA neck conditions examination, the examiner diagnosed that the Veteran had undergone a spinal fusion. The examiner opined that the Veteran’s claimed disorder is less likely than not due to or the result of the Veteran’s service connected disorder. The examiner explained that a review of medical literature did not support a relationship between the cervical spine degenerative disc disease and lumbar spine degenerative disc disease. The examiner explained that complaints of neck pain due to lumbar pain are usually due to alterations in posture. The examiner also explained that muscle contractions due to lumbar spine low back pain is likely less important in terms of placing stress on the neck that other actions such as wearing head gear, helmets, sports activities, and repetitive movements. Moreover, the examiner noted that the Veteran underwent surgery sixteen years go and there was no evidence that his cervical disorder was aggravated by his bilateral pes cavus and lumbar spine disorders. In a September 2019 VA neck conditions examination, the examiner diagnosed the Veteran with degenerative arthritis of the cervical spine. The examiner opined that the claimed disorder is less likely than not proximately due to or the result of the Veteran’s service connected disorder. The examiner explained that cervical spine x-rays from February 2000 revealed anterior subluxation of C-4 and C-5 and lower cervical degenerative change. The examiner also explained that common causes of neck subluxation are the following: trauma; motor vehicle accidents; sports injuries; and slips and falls resulting in whiplash; poor posture; neck joints subluxated by either too much flexion, extension, or rotation; arthritis; neck joint subluxations created from mild to moderate arthritis of the neck which becomes unstable with movement; and muscle spasms of the neck. The examiner also noted that risk factors for cervical degenerative disc disease include the following: genetics; obesity; smoking; and injury to the neck. The examiner opined that the Veteran’s cervical spine disorder is less likely than not proximately due to or the result of lumbosacral spine degenerative arthritis, spondylosis, and spondylolisthesis and bilateral pes cavus. The examiner also opined that the Veteran’s bilateral pes cavus and lumbar spine disorders did not aggravate his neck cervical spine disorder. The Board acknowledges the conflicting private July 2017 VA medical opinion submitted by the Veteran which supports a finding that his cervical spine disorder is related to his service connected bilateral pes cavus and lumbar spine disorder. As note, when evaluating medical opinions, it is the province of the Board to weigh the evidence and decide where to give credit and where to withhold the same, and in so doing, to also accept certain medical opinions over others. See Evans v. West, 12 Vet. App. 22, 30 (1999). The Board cannot make its own independent medical determinations, and there must be plausible reasons for favoring one opinion over another. See Colvin v. Derwinski, 1 Vet. App. 171 (1991). Generally, the degree of probative value which may be attributed to a medical opinion issued by a VA or private treatment provider takes into account such factors as its thoroughness and degree of detail and whether there was review of the Veteran’s claims file. Prejean v. West, 13 Vet. App. 444 (2000). An evaluation of the probative value of a medical opinion or diagnosis is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusions reached. See Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993). When confronted with conflicting medical opinions, the Board must weigh each and favor one competent medical expert over another if its statement of reasons and bases is adequate to support that decision. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). The Board must also determine which of the competing medical opinions is more probative of the medical question at issue. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300 (2008). The basis of the July 2017 examiners opinion focused on the Veteran’s lumbar spine disorder as causing the onset of his cervical spine disorder. While there is evidence that the Veteran experienced post-operative cervical spine pain, there is no substantial evidence in the record to support a finding that the Veteran’s cervical spine disorder is proximately related to his service connected lumbar spine disorder or bilateral pes cavus. Moreover, the examiner did not discuss that medical literature does not support a relationship between the cervical spine degenerative disc disease and lumbar spine degenerative disc disease. Thus, the Board has determined that the thorough and extensive September 2019 VA examination findings are more probative and compelling to the medical issue at question Therefore, the foregoing summary of the treatment record reveals no possibility for service connection for a cervical spine disorder on a secondary basis. Although the Veteran contends that his reported cervical spine disorder is related to his service connected lumbar spine disorder or bilateral pes cavus, there is no evidence in the record of treatment in-service for a cervical spine disorder. The Board does acknowledge that the Veteran experiences cervical spine pain; however, there is not a significant correlation between the Veteran’s cervical spine disorder and his time in-service as related to his service connected bilateral pes cavus and lumbar spine disorder. Moreover, since the July 2017 positive examiner findings, the Veteran has undergone several thorough and extensive VA cervical spine examinations which concluded that a review of medical literature did not support a relationship between the cervical spine degenerative disc disease and lumbar spine degenerative disc disease. Moreover, the examiner also explained that muscle contractions due to lumbar spine low back pain is likely less important in terms of placing stress on the neck that other actions such as wearing head gear, helmets, sports activities, and repetitive movements. Furthermore, the examiner noted that the Veteran underwent surgery sixteen years go and there was no evidence that his cervical disorder was aggravated by his bilateral pes cavus and lumbar spine disorders. Furthermore, the March 2018 examiner noted that a review of medical literature does not support a relationship between cervical spine degenerative disc disease and lumbar spine degenerative disc disease. Moreover, the September 2019 examiner noted that the most common causes of neck subluxation are the following: trauma; motor vehicle accidents; sports injuries; and slips and falls resulting in whiplash; poor posture; neck joints subluxated by either too much flexion, extension, or rotation; arthritis; neck joint subluxations created from mild to moderate arthritis of the neck which becomes unstable with movement; and muscle spasms of the neck . Lastly, The examiner opined that the Veteran’s cervical spine disorder is less not proximately due to or the result of lumbosacral spine degenerative arthritis, spondylosis, and spondylolisthesis and bilateral pes cavus. The examiner also opined that the Veteran’s bilateral pes cavus and lumbar spine disorders did not aggravate his neck cervical spine disorder. The Board also reviewed the Veteran’s lay statements asserting that the onset of his cervical spine disorder was caused by his service connected bilateral pes cavus. Lay people are competent to report on matters observed or within their personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). Therefore, the Veteran is competent to provide statements of symptoms which are observable to his senses. However, the Board must emphasize that the Veteran is not competent to interpret accurately clinical findings pertaining to a cervical spine disorder as this requires highly specialized knowledge and training. 38 C.F.R. § 3.159 (a)(1) (2018). See also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). As a pathology for the onset of a cervical disorder has not been shown to be related to the Veteran’s service-connected bilateral pes cavus or lumbar spine disorder, the Board concludes that the clinical evidence does not support the Veteran’s contentions for a granting of service connection on a secondary basis. Based on this evidence, the Board finds service connection is not warranted. The Board has considered the benefit-of-the-doubt doctrine; however, the Board does not perceive an approximate balance of positive and negative evidence. The preponderance of the evidence is against the claim, the doctrine is not applicable, and the claim must be denied. 38 U.S.C. § 5107 (b) (2012); 38 C.F.R. § 4.3 (2020). 3. Entitlement to service connection for a right knee disorder, to include as secondary to service connected bilateral pes cavus. STRS reveal that the Veteran underwent an osteotomy procedure of his fourth and fifth metatarsals on September 1984 for bilateral pes planus. Due to the severity of the Veteran’s bilateral pes planus, he was medically discharged from military service. STRS do not reveal any complaints diagnosis or treatments for a right knee disorder. At an examination prior to separation, the Veteran’s right knee was noted as normal with no findings of arthritis, bone, or joint deformities diagnosed. April 1998 private treatment records reveal that the Veteran presented with complaints of radiating right knee pain which he described as sharp. The Veteran reported that he developed his right knee pain in 1997 while employed as a truck driver. November 1998 VA outpatient treatment records reveal subjective complaints by the Veteran of right knee pain related to his right foot surgery. February 1999 VA outpatient treatment records reveal that the Veteran was diagnosed with longstanding severe right knee pain. X-ray findings indicate degenerative changes in the right knee. In a March 2000 VA examiner knee examination, the examiner reported that the Veteran has had right knee pain for several years which is related to the onset of his obesity and degenerative joint disease of the right knee. The examiner also noted that the Veteran underwent right foot surgery seventeen years ago and has favored his right side since. The examiner explained that the Veteran’s favoring of his right side might have contributed to his right knee pain. In a June 2017 private examiner opinion, the examiner diagnosed the Veteran with chondromalacia of the right knee. The examiner explained that the Veteran’s altered gait due to his foot problems and morbid obesity do not make it possible to determine which contributed to his right knee problems. The examiner opined that it is as likely as not that the Veteran’s service connected pes cavus aggravated and contributed to his right knee chondromalacia. December 2017 private treatment records reveal that the Veteran reported right knee swelling related to his December 2017 right foot surgery. The Veteran was diagnosed as negative for lower extremity venous duplex with no evidence of deep vein thrombosis. In a March 2018 VA knee conditions examination, the examiner diagnosed the Veteran with patellofemoral pain syndrome of the right knee. The examiner opined that the Veteran’s claimed disorder is less likely than not due to or the result of the Veteran’s service connected disorder. The examiner explained that the Veteran’s right leg pain due to his foot surgery would increase the load on his normal left leg. The increase in the left leg load will result in an increase in pain or a pathology of the left leg pain rather than right leg pain since the Veteran is favoring the left leg. Thus, it is less likely than not that the Veteran’s right knee disorder is caused by his altered gait. In a February 2019 VA knee conditions examination, the examiner diagnosed the Veteran with patellofemoral pain syndrome of the right knee. The examiner opined that the Veteran’s claimed disorder is less likely than not due to or the result of the Veteran’s service connected disorder. The examiner explained that the Veteran had x-rays of the right knee in September 2019. These x-rays showed chondrocalcinosis of the medial and lateral meniscus. This is a disorder characterized by the accumulation of calcium pyrophosphate dihydrate (CPPD) crystals in connective tissues or the joint cartilages. Although the exact cause of the disorder is not known, evidence suggests that it might have a hereditary association. The examiner also explained that chondrocalcinosis is mostly seen in aged patients as an increased accumulation of CPPD crystals occurs in the joints with advancing age. The examiner also noted that apart from the deposition of CPPD, the following factors may lead to the development of this disorder: hyperparathyroidism; hypercalcemia; gout; trauma; arthritides; hemochromatosis; Wilson disease; ochronosis; hypothyroidism; hypomagnesaemia. The examiner also explained that certain risk factors predispose some individuals to this disease. These include an injury, dehydration or a joint surgery. The examiner noted that the Veteran did not mention knee pain occurring after a specific injury, nor did he have surgery performed on the right knee. Rather, he reports the knee pain as secondary to the right foot pes cavus and attempted surgical correction of the right foot, which are not factors that predispose a person to chondrocalcinosis. The examiner opined that as a result, the Veteran’s right knee disorder is less likely than not a result of pes cavus. The examiner also opined that the Veteran’s bilateral pes cavus disorder did not aggravate his right knee disorder. The Board acknowledges the conflicting private medical opinions submitted by the Veteran which supports a finding that his right knee disorder is related to his service connected bilateral pes cavus disorder. When evaluating medical opinions, it is the province of the Board to weigh the evidence and decide where to give credit and where to withhold the same, and in so doing, to also accept certain medical opinions over others. See Evans v. West, 12 Vet. App. 22, 30 (1999). The Board cannot make its own independent medical determinations, and there must be plausible reasons for favoring one opinion over another. See Colvin v. Derwinski, 1 Vet. App. 171 (1991). Generally, the degree of probative value which may be attributed to a medical opinion issued by a VA or private treatment provider takes into account such factors as its thoroughness and degree of detail and whether there was review of the Veteran’s claims file. Prejean v. West, 13 Vet. App. 444 (2000). An evaluation of the probative value of a medical opinion or diagnosis is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusions reached. See Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993). When confronted with conflicting medical opinions, the Board must weigh each and favor one competent medical expert over another if its statement of reasons and bases is adequate to support that decision. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). The Board must also determine which of the competing medical opinions is more probative of the medical question at issue. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300 (2008). The basis of the examiner opinions focused on the Veteran’s pes cavus disorder as causing the onset of his right knee disorder. While there is evidence that the Veteran experiences bilateral knee pain, there is no substantial evidence in the record to support a finding that the Veteran’s right knee disorder is proximately related to his service connected bilateral pes cavus. Moreover, the February 2019 examiner noted that surgical correction of the right foot is not a factor that predispose a person to chondrocalcinosis. The examiner opined that as a result, the Veteran’s right knee disorder is less likely than not a result of pes cavus. Thus, the Board has determined that the thorough and extensive February 2019 VA examination findings are more probative and compelling to the medical issue at question Therefore, the foregoing summary of the treatment record reveals no possibility for service connection for a right knee disorder on a secondary basis. Although the Veteran contends that his reported right knee disorder is related to his service connected bilateral pes cavus disorder, there is no evidence in the record of treatment in-service for a right knee disorder. The Board does acknowledge that the Veteran experiences right knee pain; however, there is not a significant correlation between the Veteran’s right knee disorder and his time in-service as related to his service connected bilateral pes cavus. Moreover, since the July 2017 positive examiner findings, the Veteran has undergone several thorough and extensive VA right knee examinations which concluded that the Veteran’s right leg pain due to his foot surgery would increase the load on his normal left leg. The increase in the left leg load would more likely result in an increase in pain or a pathology of the left leg pain rather than right leg pain since the Veteran is favoring the left leg. Moreover, the examiner explained that the Veteran’s diagnosed right knee chondrocalcinosis is mostly seen in aged patients as an increased accumulation of CPPD crystals occurs in the joints with advancing age. The examiner also noted that apart from the deposition of CPPD, the following factors may lead to the development of this disorder: hyperparathyroidism; hypercalcemia; gout; trauma; arthritides; hemochromatosis; Wilson disease; ochronosis; hypothyroidism; and hypomagnesaemia. The examiner also explained that certain risk factors predispose some individuals to this disease. These include an injury, dehydration or a joint surgery. The examiner noted that the Veteran did not mention knee pain occurring after a specific injury, nor did he have surgery performed on the right knee. Rather, he reports the knee pain as secondary to the right foot pes cavus and attempted surgical correction of the right foot, which are not factors that predispose a person to chondrocalcinosis. The examiner opined that as a result, the Veteran’s right knee disorder is less likely than not a result of pes cavus. The examiner also opined that the Veteran’s bilateral pes cavus disorder did not aggravate his right knee disorder. The Board also reviewed the Veteran’s lay statements asserting that the onset of his right knee disorder was caused by his service connected bilateral pes cavus. Lay people are competent to report on matters observed or within their personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). Therefore, the Veteran is competent to provide statements of symptoms which are observable to his senses. However, the Board must emphasize that the Veteran is not competent to interpret accurately clinical findings pertaining to a right knee disorder as this requires highly specialized knowledge and training. 38 C.F.R. § 3.159 (a)(1) (2018). See also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). As a pathology for the onset of a right knee disorder has not been shown to be related to the Veteran’s service-connected bilateral pes cavus, the Board concludes that the clinical evidence does not support the Veteran’s contentions for a granting of service connection on a secondary basis. Based on this evidence, the Board finds service connection is not warranted. The Board has considered the benefit-of-the-doubt doctrine; however, the Board does not perceive an approximate balance of positive and negative evidence. The preponderance of the evidence is against the claim, the doctrine is not applicable, and the claim must be denied. 38 U.S.C. § 5107 (b) (2012); 38 C.F.R. § 4.3 (2020). 4. Entitlement to service connection for diabetes mellitus, to include as secondary to trichloroethylene exposure. The Veteran contends that his diabetes mellitus is secondary to trichloroethylene (TCE) exposure. Specifically, the Veteran asserts that he was exposed to TCE while stationed and working in the research lab at Fort Dix, New Jersey and Fort Lewis, Washington. STRs reveal that the Veteran underwent a osteotomy procedure of his fourth and fifth metatarsals on September 1984 for bilateral pes planus. Due to the severity of the Veteran’s bilateral pes planus, he was medically discharged from military service. STRs do not reveal any complaints diagnosis or treatments for diabetes mellitus. At an examination prior to the Veteran’s medical separation, the examiner did not diagnose any findings of diabetes mellitus. In a June 2017 private examiner opinion, the examiner diagnosed the Veteran with diabetes and opined that the onset of the Veteran’s diabetes is most likely related to his morbid obesity. In a March 2018 VA diabetes examination, the examiner diagnosed the Veteran with diabetes mellitus type II. The examiner opined that the Veteran’s diabetes mellitus is less likely than not incurred in or caused by the claimed in-service exposure to TCE. The examiner noted that the Agency for Toxic Substances and Disease Registry does not list diabetes mellitus as a side effect of TCE exposure. Therefore, it is less likely than not that the Veteran’s diabetes mellitus is related to his exposure to TCE. In a September 2019 VA addendum opinion, the examiner opined that it is unlikely that the Veteran’s exposure to TCE caused the onset of his diabetes mellitus. The examiner explained that the Agency for Toxic Substance and Disease registry is a federal public health agency of the U.S. Department of Health and Human Services. The agency’s mission is to protect communities from harmful health effects of exposure to natural and man-made hazardous substances. The examiner noted that the known effects of exposure to TCE include the following: damage to some of the nerves in the face; nervous system effects related to hearing; seeing; balance; changes in the rhythm of the heartbeat; liver damage; and kidney damage. The examiner also noted that there is strong evidence that TCE can cause kidney cancer in people and some evidence that it causes liver cancer and malignant lymphoma; and scleroderma. Lastly the examiner noted that at present, there are few, if any, studies that show a relationship between TCE and diabetes. Therefore, the examiner opined that because of a lack of evidence of a link between TCE and diabetes, it is unlikely that the Veteran’s diabetes is due to TCE exposure. The foregoing summary of the treatment record reveals no possibility for service connection for diabetes mellitus on a secondary basis. Although the Veteran contends that his reported diabetes mellitus disorder is related to his in-service exposure to TCE, there is no evidence in the record of treatment in-service for diabetes mellitus. The Board does acknowledge that the Veteran has a diagnosis of diabetes mellitus; however, there is not a significant correlation between the Veteran’s diabetes mellitus and his time in-service as related to his service exposure to TCE. Moreover, the Veteran has undergone several thorough and extensive VA diabetes examinations since his separation from service. The examiner concluded that the Agency for Toxic Substances and Disease Registry does not list diabetes mellitus as a side effect of TCE exposure. Moreover, the examiner noted that at present, there are few, if any, studies that show a relationship between TCE and diabetes. The Board also reviewed the Veteran’s submission of medical literature concerning TCE exposure. None of the medical literature submitted by the Veteran establishes evidence of a direct correlation between exposure to TCE and the onset of the Veteran’s diabetes mellitus. Therefore, the examiner opined that because of a lack of evidence of a link between TCE and diabetes, it is unlikely that the Veteran’s diabetes is due to TCE exposure. Moreover, the examiner opinion determined that it is more likely that the onset of the Veteran’s diabetes mellitus was caused by his morbid obesity and not his exposure to TCE. The Board also reviewed the Veteran’s lay statements and medical literature asserting that the onset of his diabetes mellitus was caused by his in-service exposure to TCE. Lay people are competent to report on matters observed or within their personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). Therefore, the Veteran is competent to provide statements of symptoms which are observable to his senses. However, the Board must emphasize that the Veteran is not competent to interpret accurately clinical findings pertaining to diabetes mellitus as this requires highly specialized knowledge and training. 38 C.F.R. § 3.159 (a)(1) (2018). See also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). As a pathology for the onset of diabetes mellitus has not been shown to be related to the Veteran’s in-service exposure to TCE, the Board concludes that the clinical evidence does not support the Veteran’s contentions for a granting of service connection on a secondary basis. Based on this evidence, the Board finds service connection is not warranted. The Board has considered the benefit-of-the-doubt doctrine; however, the Board does not perceive an approximate balance of positive and negative evidence. The preponderance of the evidence is against the claim, the doctrine is not applicable, and the claim must be denied. 38 U.S.C. § 5107 (b) (2012); 38 C.F.R. § 4.3 (2020). MICHAEL D. LYON Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board M. Elliot Harris, 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.