Citation Nr: 21011374 Decision Date: 03/01/21 Archive Date: 03/01/21 DOCKET NO. 16-53 248A DATE: March 1, 2021 ORDER Service connection for a back disability is denied. A rating in excess of 10 percent prior to February 23, 2015 for right knee medial meniscus tear with degenerative arthrosis due to painful motion is denied. A rating in excess of 10 percent from April 1, 2015 to October 5, 2015 for right knee medial meniscus tear with degenerative arthrosis due to painful motion is denied. A separate 20 percent rating from April 1, 2015 to October 5, 2015 for symptomatic right knee meniscal tear is granted. A separate 10 percent rating from April 1, 2015 to October 5, 2015 for mild recurrent instability is granted. A rating in excess of 10 percent from December 1, 2015 to July 18, 2018 for right knee medial meniscus tear with degenerative arthrosis due to painful motion is denied. A separate 10 percent rating from December 1, 2015 to July 18, 2018 for symptomatic removal of right knee meniscus is granted. A separate 10 percent rating from December 1, 2015 to July 18, 2018 for mild recurrent instability is granted. A 100 percent rating for right knee unicompartmental arthroplasty from November 1, 2018 to July 18, 2019 is granted; a 60 percent rating is granted thereafter. Entitlement to a total disability rating based on individual unemployability (TDIU) is granted prior to February 23, 2015; from April 1, 2015 to October 5, 2015; from December 1, 2015 to July 18, 2018, and since July 19, 2019. Entitlement to TDIU is moot from November 1, 2018 to July 18, 2019. Entitlement to special monthly compensation (SMC) based on statutory housebound status under 38 U.S.C. § 1114(s) for the period from November 1, 2018 to July 18, 2019 is granted. FINDINGS OF FACT 1. The Veteran’s back disability is not secondary to his service-connected right knee disability and is not otherwise related to an in-service injury or disease. 2. Prior to February 23, 2015, the Veteran’s right knee disability was manifest by painful flexion. 3. From April 1, 2015 to October 5, 2015, the Veteran’s right knee disability was manifest by painful flexion, a symptomatic tear of the semilunar cartilage, and recurrent mild instability. 4. From December 1, 2015 to July 18, 2018, the Veteran’s right knee disability was manifest by painful flexion, symptomatic removal of the semilunar cartilage, and recurrent mild instability. 5. The Veteran underwent a partial knee replacement on July 19, 2018. 6. Following the Veteran’s partial right knee replacement, his right knee disability was manifested by chronic severe painful motion. 7. Prior to February 23, 2015; from April 1, 2015 to October 5, 2015; from December 1, 2015 to July 18, 2018; and since July 19, 2019, the Veteran’s service-connected disabilities have precluded substantially gainful employment. 8. From November 1, 2018 to July 18, 2019, the Veteran was in receipt of a combined 100 percent schedular disability rating. 9. From November 1, 2018 to July 18, 2019, in addition to a 100 percent rating for a right knee disability, the Veteran had additional service-connected disabilities independently ratable as at least 60 percent disabling. CONCLUSIONS OF LAW 1. The criteria for service connection for a back disability due to service or a service-connected right knee disability are not met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.310. 2. Prior to February 23, 2015, the criteria for a rating in excess of 10 percent for right knee painful motion were not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5003. 3. From April 1, 2015 to October 5, 2015, the criteria for a rating in excess of 10 percent for right knee painful motion were not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5003. 4. From April 1, 2015 to October 5, 2015, the criteria for a 20 percent rating for a right knee semilunar cartilage tear were met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5258. 5. From April 1, 2015 to October 5, 2015, the criteria for a 10 percent rating for mild right knee instability were met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5257. 6. From December 1, 2015 to July 18, 2018, the criteria for a rating in excess of 10 percent for right knee painful motion were not met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5003. 7. From December 1, 2015 to July 18, 2018, the criteria for a 10 percent rating for symptomatic removal of the right knee semilunar cartilage were met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5259. 8. From December 1, 2015 to July 18, 2018, the criteria for a 10 percent rating for mild right knee instability were met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.71a, Diagnostic Code 5257. 9. The criteria for a 100 percent rating for a one-year period for partial right knee replacement were met from July 19, 2018 to July 18, 2019. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 4.1-4.7, 4.71a, Diagnostic Code 5055. 10. Since July 19, 2019, the criteria for a 60 percent rating for severe residuals of a partial right knee replacement have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 4.1-4.7, 4.71a, Diagnostic Code 5055. 11. Prior to February 23, 2015; from April 1, 2015 to October 5, 2015; from December 1, 2015 to July 18, 2018; and since July 19, 2019, the criteria for entitlement to TDIU have been met. 38 U.S.C. § 1155; 38 C.F.R. §§ 3.340, 3.341, 4.16. 12. From November 1, 2018 to July 18, 2019, entitlement to TDIU was moot. 38 U.S.C. § 1155; 38 C.F.R. § 4.16. 13. From November 1, 2018 to July 18, 2019, the criteria for SMC at the housebound rate were met. 38 U.S.C. §§ 1114 (s), 5103, 5107; 38 C.F.R. §§ 3.102, 3.350. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from December 1998 to July 2001. The Veteran requested a Board hearing in his January 2017 VA Form 9, but withdrew that request in an August 2019 letter. The Board remanded the claims in January 2020. After the Board’s remand, in a December 2020 rating decision, the Agency of Original Jurisdiction (AOJ) granted the Veteran a temporary total rating for his right knee disability for periods including October 6, 2015 to November 30, 2015 and July 19, 2018 to October 31, 2018. The AOJ also granted SMC at the housebound rate for those two periods, as well the period from February 23, 2015 to March 31, 2015, during which the Veteran’s right knee disability was rated as 100 percent disability. The Veteran’s benefits for those periods have been maximized and they are no longer on appeal. Service Connection 1. Back Disability The Veteran contends that his back disability is secondary to his service-connected right knee disability, or, alternatively, is related to his active-duty service. Service connection may be granted for a disability that is proximately due to, or aggravated by, service-connected disease or injury. 38 C.F.R. § 3.310. Service connection may also be granted for disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. § 3.303. The three-element test for service connection requires evidence of: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the current disability and the in-service disease or injury. Shedden v. Principi, 381 F.3d 1163, 1166 -67 (Fed. Cir. 2004). The Veteran has back strain and degenerative arthritis. See July 2020 VA Examination. But the Board concludes that the preponderance of the evidence is against finding that the Veteran’s back disability is proximately due to, the result of, or aggravated beyond its natural progression by, his service-connected right knee disability. 38 U.S.C. §§ 1110, 1131; Allen v. Brown, 7 Vet. App. 439 (1995) (en banc); 38 C.F.R. § 3.310(a). The preponderance of the evidence is also against finding that the Veteran’s back disability began during active service, or is otherwise related to an in-service injury, event, or disease. The Veteran’s service treatment records are silent for any complaint or treatment related to his lumbar spine. The Veteran’s post-service treatment private records first indicate complaints of back pain the day after he was in a motor vehicle accident in January 2006. The July 2020 VA examiner opined the Veteran’s degenerative arthritis of the lumbar spine is less likely than not caused or aggravated beyond its natural progression resulting from his right knee disability. The examiner noted the sites are anatomically separate in location and the compensatory gait and mechanics due to the Veteran’s knee pain are not likely to affect his lumbar spine. Furthermore, the examiner continued, the Veteran’s right knee pain began in June 1999, but he did not report back pain until 2006 after a motor vehicle accident. See January 2006 Private Treatment Records. The examiner explained that radiological findings of degenerative arthritis may evolve over several years, most often evident within ten years. But considering there was no report of back pain in 2001, that the Veteran was in a motor vehicle accident causing back pain in 2006, and the current diagnosis of lumbar degenerative arthritis, it was most likely that the lumbar degenerative arthritis was due to the motor vehicle accident in 2006. The Veteran believes his back disability is proximately due to or the result of, or was aggravated beyond its natural progression by, his service-connected right knee disability. But the Veteran is not competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the musculoskeletal system and the anatomical relationships between multiple joints. It is outside the competence of the Veteran because the record does not show that he has the skills or medical training to make such a determination. Jandreau v. Nicholson, 492 F.3d 1372, 1377 n.4 (Fed. Cir. 2007); see also Kahana v. Shinseki, 24. Vet. App. 428 (2011). During a November 2013 Social Security Administration (SSA) evaluation, the Veteran reported he had injured his back in 2001 while lifting, had an MRI and was told something was wrong. But, as noted above, the medical record is silent for any treatment related to his back in 2001 and at no point prior to November 2013 had the Veteran made any statement relating his back pain to an in-service injury. Then, during a May 2016 DRO hearing, the Veteran asserted he injured his back when he was slammed between his ship and a boat they were putting into the water but did not go to sick call because he was told it was probably just a sprain and that he should not worry about it. See May 2016 DRO Hearing Transcript, at 7-8. The Veteran then contradicted his November 2013 statement, asserting he had undergone an MRI in 2002, which showed a herniated disc. Id. at 8. The Board finds that the Veteran’s assertions are inconsistent with each other, as well as with the medical evidence. As such, the Board finds the Veteran’s assertions lack credibility and affords them them no probative value. See Caluza v. Brown, 7 Vet. App. 498, 511-12 (1995), aff’d per curiam, 78 F.3d. 604 (Fed. Cir. 1996). Further, the July 2020 VA examiner opined that the Veteran’s back disability was less likely than not incurred in or caused by his service. The examiner explained that the Veteran’s service treatment records were silent for a diagnosis related to low back pain, including a June 2001 separation physical in which the Veteran denied lower back pain. As with secondary service connection, the examiner noted that the Veteran initially reported back pain in 2006, when he attributed the pain to a motor vehicle accident. While the Veteran believes his back disability is related to an in-service injury, the Board reiterates that the preponderance of the evidence weighs against findings that the in-service back injury occurred. Consequently, the Board gives more probative weight to the VA examiner’s opinion. Upon careful review and weighing of the evidence, with reasoning as detailed above, the Board finds that the preponderance of the evidence is against the claim for service connection for a low back disability and the benefit of the doubt doctrine is not for application. See generally Gilbert v. Derwinski, 1 Vet. App. 49 (1990); Ortiz v. Principi, 274 F.3d 1361 (Fed Cir. 2001). The appeal must therefore be denied. Increased Rating 2. Right Knee The Veteran contends that he is entitled to a higher rating for his service-connected right knee disability. The Veteran has undergone several knee surgeries throughout the appeal period and, as a result, has been granted three separate periods of temporary total ratings from February 23, 2015 to March 31, 3015, from October 6, 2015 to November 30, 2015, and from July 19, 2018 to October 31, 2018. As the Veteran has been granted a total rating for these periods, they are not on appeal. For the Periods Prior to February 23, 2015, from April 1, 2015 to October 5, 2015, and from December 1, 2015 to July 18, 2018 A. Limitation of Motion For these periods, the assigned Diagnostic Code 5260 suggests that the Veteran’s right knee disability is rated based on compensable limitation of flexion. 38 C.F.R. § 4.71a. A review of the evidence reflects that the right knee disability has manifested as osteoarthritis and been rated based on painful noncompensable limitation of motion, and that the Veteran’s right knee has not had compensable limitation of motion (i.e. limitation of flexion or extension) at any time during the relevant rating period. Therefore, the Diagnostic Code assigned should have been Diagnostic Code 5003, to show that the right knee with osteoarthritis is being rated based on noncompensable limitation of motion that is painful. For this reason, the Board is changing the Diagnostic Code for the right knee to 5003 to reflect the actual rating already assigned. 38 C.F.R. § 4.71a. The Veteran’s right knee disability is rated under 38 C.F.R. § 4.71a, Diagnostic Code 5260, for limitation of flexion of the leg. Under Diagnostic Code 5260, a noncompensable rating is warranted for flexion limited to 60 degrees. A 10 percent rating is warranted for flexion limited to 45 degrees. A 20 percent rating is warranted for flexion limited to 30 degrees. A 30 percent rating is warranted for flexion limited to 15 degrees. 38 C.F.R. § 4.71a, Diagnostic Code 5260. When evaluating musculoskeletal disabilities based on limitation of motion, 38 C.F.R. § 4.40 requires consideration of functional loss caused by pain or other factors listed in that section that could occur during flare-ups or after repeated use and, therefore, not be reflected on range-of-motion testing. 38 C.F.R. § 4.45 requires consideration also be given to less movement than normal, more movement than normal, weakened movement, excess fatigability, incoordination, and pain on movement. See DeLuca v. Brown, 8 Vet. App. 202 (1995); see also Mitchell v. Shinseki, 25 Vet. App. 32, 44 (2011). Nonetheless, even when the background factors listed in § 4.40 or 4.45 are relevant when evaluating a disability, the rating is assigned based on the extent to which motion is limited, pursuant to 38 C.F.R. § 4.71a; a separate or higher rating under § 4.40 or 4.45 itself is not appropriate. See Thompson v. McDonald, 815 F.3d 781, 785 (Fed. Cir. 2016) (“[I]t is clear that the guidance of § 4.40 is intended to be used in understanding the nature of the veteran’s disability, after which a rating is determined based on the § 4.71a criteria.”). Under 38 C.F.R. § 4.59, painful motion is a factor to be considered with any form of arthritis; however, 38 C.F.R. § 4.59 is not limited to disabilities involving arthritis. See Burton v. Shinseki, 25 Vet. App. 1 (2011). The Board finds that the preponderance of the evidence is against a rating in excess of 10 percent for the Veteran’s right knee disability due to a limitation of motion for the periods prior to February 23, 2015, from April 1, 2015 to October 5, 2015, and from December 1, 2015 to July 18, 2018. The Board acknowledges the Veteran’s lay reports of symptoms and that there was functional loss due to pain, pain during flare-ups, and pain during repetitive use over time. However, even considering the Veteran’s lay reports of symptoms and noted functional loss, the degree of additional limitation reflected by the statements during the October 2016 VA examination that he experiences flare ups two to three times per week would not result in limitation of motion more nearly approximating flexion limited to 30 degrees. Throughout the applicable appeal periods, the Veteran has had flexion appreciably greater than 30 degrees. See, e.g., July 2015 Private Treatment Records; September 2015 Private Treatment Records; April 2017 VA Treatment Records; May 2017 VA Treatment Records; April 2018 VA Treatment Records. During a December 2014 VA examination, the Veteran denied any flare ups and had normal range of motion. During the October 2016 VA examination, the Veteran had 110 degrees of flexion with pain. The Veteran was examined after repetitive use over time and had increased pain, weakness, fatigue, and lack of endurance, but the examiner still reported 110 degrees of flexion. Despite the Veteran’s reports of multiple flare ups per week, the examiner did not give an estimate for any additional loss that would have resulted. The examination is therefore inadequate. However, even affording the October 2016 VA examination limited probative weight, the other medical lay evidence that indicates the Veteran’s right knee was limited to 90 degrees of flexion at its worst. See May 2017 VA Treatment Records. The Board has also considered the other Diagnostic Codes pertaining to the knee and leg. Other disability ratings may be assigned only if the symptomatology for a disability is not duplicative or overlapping with the symptomatology of any other disability. See Esteban v. Brown, 6 Vet. App. 259, 261-62 (1994); Lyles v. Shulkin, 29 Vet. App. 107 (2017) (holding that 38 C.F.R. § 4.14 prohibits paying compensation twice for the same symptoms or functional impairment). The evidence does not support assigning a separate rating for limitation of extension. 38 C.F.R. § 4.71a, Diagnostic Code 5261. B. Instability Diagnostic Code 5257 provides ratings for other knee impairments with the following ratings assigned: 10 percent for slight, 20 percent for moderate, and 30 percent for severe recurrent subluxation or lateral instability. 38 C.F.R. § 4.71a, Diagnostic Code 5257. The words “slight,” “moderate,” and “severe” as used in the various diagnostic codes are not defined in the VA Rating Schedule. Rather than applying a mechanical formula, the Board must evaluate all the evidence, to the end that its decisions are “equitable and just.” 38 C.F.R. § 4.6.   Objective medical evidence of knee instability is not required, and objective medical evidence is not categorically more probative than lay evidence. English v. Wilkie, 30 Vet. App. 347.  Prior to February 23, 2015, there is no indication that the Veteran’s right knee had any degree of instability. The December 2014 VA examination report indicates he had good stability. On the other hand, during the periods from April 1, 2015 to October 5, 2015 and December 1, 2015 to July 18, 2018, the Veteran made subjective reports of instability and giving way. See July 2015 VA Treatment Records; September 2015 Private Treatment Records; October 2015 Private Treatment Records; October 2016 VA Examination Report. But objective testing consistently documented normal stability. Id.; April 2017 VA Treatment Records; April 2018 VA Treatment Records Therefore, because the Veteran made subjective reports of instability but objective testing was consistently normal, the Board finds that the Veteran’s symptoms most nearly approximate mild recurrent instability and a separate 10 percent rating, but no higher, is warranted for the periods from April 1, 2015 to October 5, 2015 and from December 1, 2015 to July 18, 2018. 38 C.F.R. § 4.71a, Diagnostic Code 5257. C. Semilunar Cartilage Prior to February 23, 2015, the Veteran did not have any of the symptoms required for a separate rating under Diagnostic Code 5258. See December 2014 VA Examination Report. On February 23, 2015, the Veteran underwent arthroscopic knee surgery for meniscal repair. During the period from April 1, 2015 to October 5, 2015, which followed a period of temporary total rating for the surgery, the Veteran experienced frequent episodes of locking, pain, and effusion. See, e.g., June 2015 VA Treatment Records; September 2015 Private Treatment Records. A separate 20 percent rating is therefore warranted for this period. On October 6, 2015, the Veteran underwent a meniscectomy of the right knee. The Veteran continued to have meniscal symptoms during the period from December 1, 2015 to July 18, 2018, which followed a period of temporary total rating for the surgery. See October 2016 VA Examination Report. Therefore, a 10 percent rating pursuant to Diagnostic Code 5259 is warranted this period. D. Additional Conditions   The Board has also considered whether an additional or higher rating would be available under other diagnostic codes pertaining to the knee. There is no indication of ankylosis; no impairment of the tibia or fibula; and no diagnosis of genu recurvatum. As such, there is no basis for a separate evaluation under Diagnostic Codes 5256, 5262, or 5263. From November 1, 2018 to July 18, 2019 The Veteran underwent a unicompartmental arthroplasty – or partial right knee replacement - on July 19, 2018. The AOJ awarded the Veteran a temporary total rating from July 19, 2018 to October 31, 2018. However, the Board finds that the Veteran is entitled to a 100 percent rating for a full one-year period following the surgery pursuant to 38 C.F.R. § 4.71a, Diagnostic Code 5055. Under 38 C.F.R. § 4.71a, Diagnostic Code 5055, replacement of either knee joint warrants a 100 percent evaluation for a one-year period following implantation of the prosthesis. Thereafter, a minimum rating is 30 percent warranted and a 60 percent evaluation is warranted if there are chronic residuals consisting of severely painful motion or severe weakness in the affected extremity. With intermediate degrees of residual weakness, pain or limitation of motion, the disability will be rated by analogy to Diagnostic Codes 5256, 5261 or 5262. The provisions of Diagnostic Code 5055 are applicable to partial knee replacements. Hudgens v. McDonald, 823 F.3d 630 (Fed. Cir. 2016). The Veteran is therefore entitled to a 100 percent rating for a partial right knee replacement for the full 12-month regulatory period under Diagnostic Code 5055. The Veteran has been granted a 100 percent rating for a portion of the period but is entitled to an additional period of 100 percent rating from November 1, 2018 to July 18, 2019. Since July 19, 2019 In October 2020, the Veteran reported pain in his right knee, which he described as 5 out of 10. Then, in a January 2020 VA treatment record, the Veteran reported increased pain and effusion that was worse with activity. The Veteran had flexion to 110 degrees, and the provider suspected tibial loosening but was not certain. During a July 2020 VA examination, the Veteran reported constant dull pain that was occasionally severe. He stated his knee felt pretty good since surgery, but he had severe flare ups approximately every two months lasting two to three days each. On examination, the Veteran had 115 degrees of flexion with pain. The examiner estimated the Veteran would be limited to 90 degrees of flexion after repetitive use over time and 70 degrees of flexion during flare ups, both due to pain. The examiner commented that the Veteran’s had significant pain during flare ups. As mentioned above, following a 100 percent disability rating for one year for a knee replacement, Diagnostic Code 5055 allows for a 60 percent rating if there are chronic residuals consisting of severely painful motion or severe weakness in the affected extremity. With intermediate degrees of residual weakness, pain or limitation of motion, the disability will be rated by analogy to Diagnostic Codes 5256, 5261 or 5262. The mandatory minimum rating is 30 percent. While the Veteran’s right knee appeared to improve initially after his partial knee replacement, it is clear from the medical records that he is now experiencing increasing pain that is at times very severe. Based on the pertinent evidence of record, the Board finds that the Veteran’s right knee condition warrants a 60 percent disability rating under Diagnostic Code 5055 for the period since July 19, 2019. Finally, VA promulgated a final rule amending the regulations governing the rating musculoskeletal disabilities, including the knees, while the Veteran’s claim was pending. 85 Fed. Reg. 76,453 (Nov. 30, 2020) (eff. Feb. 7, 2021). The Board must evaluate the Veteran’s claim under both sets of schedular criteria beginning on the effective date of the amendment, applying the most beneficial to the Veteran. See Kuzma v. Principi, 341 F.3d 1327, 1328 (Fed. Cir. 2003). The Board has considered the applicable post-amendment Diagnostic Codes and finds that the pre-amendment regulations are more advantageous. As discussed above, the Board has assigned a 60 percent rating under Diagnostic Code 5055 for the residuals of the Veteran’s partial knee replacement. Note (3) of the amended rating criteria for Prosthetic Implants and Resurfacing explicitly limits the application of Diagnostic Code 5055 to total knee replacements. Therefore, under the amended rating criteria the Veteran’s right knee would instead be evaluated under the other Diagnostic Codes applicable to the knee. The maximum single rating available under the post-amendment regulation is 60 percent under Diagnostic Code 5256, which is assigned for extremely unfavorable ankylosis in flexion at an angle of 45 degrees or more. There is no medical or lay evidence indicating the Veteran’s right knee has worsened to the point of ankylosis. In the most recent July 2020 VA examination, the Veteran had 115 degrees of flexion, which was further limited to 70 degrees during a flare up. And while the most recent medical evidence predates the amended regulations, the Board finds that a remand for a new VA examination is unnecessary because the Veteran has not asserted that his disability has worsened since the most recent VA examination. And, in this case, the rating assigned under the pre-amendment Diagnostic Code 5055 is equal to the highest rating available to the Veteran under the post-amendment Diagnostic Codes and absent an assertion of worsening, a remand would simply cause unnecessary delay. 3. TDIU It is the established policy of VA that all veterans who are unable to secure and follow a substantially gainful occupation due to service-connected disabilities shall be rated totally disabled. 38 C.F.R. § 4.16. A finding of total disability is appropriate “when there is present any impairment of mind or body which is sufficient to render it impossible for the average person to follow a substantially gainful occupation.” 38 C.F.R. §§ 3.340 (a)(1), 4.15. Specifically, if there is only one such disability, this disability shall be ratable at 60 percent or more; if there are two or more disabilities, there shall be at least one disability that is ratable at 40 percent or more and sufficient additional disability to bring the combined rating to 70 percent or more. 38 C.F.R. §§ 3.340, 3.341, 4.16(a). For the stated purpose of one 60 percent disability, or one 40 percent disability in combination, the following will be considered as one disability: (1) disabilities of one or both upper extremities, or of one or both lower extremities, including the bilateral factor, if applicable; and (2) disabilities resulting from common etiology or a single accident. 38 C.F.R. § 4.16 (a). “Substantially gainful employment” is that employment “which is ordinarily followed by the nondisabled to earn their livelihood with earnings common to the particular occupation in the community where the veteran resides.” Moore v. Derwinski, 1 Vet. App. 356, 358 (1991). “Marginal employment shall not be considered substantially gainful employment.” 38 C.F.R. §§ 4.16 (a). The United States Court of Appeals for Veterans Claims (Court), in Ray v. Wilkie, 31 Vet. App. 58 (2019), interpreted the phrase “unable to secure and follow a substantially gainful occupation” under 38 C.F.R. § 4.16 (b). The Court defined the term to have two components: one economic and one noneconomic. The economic component means an occupation earning more than marginal income (outside of a protected environment) as determined by the U.S. Department of Commerce as the poverty threshold for one person. The non-economic component, which is pertinent in this case, includes consideration of: The Veteran’s history, education, skill, and training; whether the veteran has the physical ability to perform the type of activities required by the occupation at issue; and whether the veteran has the mental ability to perform the activities required by the occupation at issue. The Veteran has met the schedular criteria for TDIU for the entire appeal period. See 38 C.F.R. § 4.16 (a). But the Board must still consider whether his service-connected disabilities have precluded him from securing and following substantially gainful employment for that period. See 38 C.F.R. §§ 3.341, 4.16(a); see also Hatlestad v. Brown, 5 Vet. App. 524, 529 (1993). In his May 2014 Application for Increased Compensation Based on Unemployment, the Veteran asserted he was too disabled to work due to his back and knees, last worked in September 2013, and had worked in positions doing maintenance, heating and air conditioning, and as an electrician. In an August 2014 letter, Dr. I.O. opined that the Veteran would be unable to work at least in part to his knees and psychiatric disorders. A May 2015 VA treatment record documents that the Veteran dropped out of the ninth grade, left his last job due to his knee pain and had several angry outbursts with his supervisor. VA examiners in October 2016 and July 2020 opined that the Veteran’s knee disability would affect work that required physical exertion involving his knee. The Veteran’s psychiatric disorders, which are rated as 70 percent disabling, are manifest by serious symptoms that would create a serious impediment to employment, such as difficulty adapting to stressful circumstances, disturbances of motivation and mood, and continual auditory hallucinations. Considering the Court’s holding in Ray, the Board finds significant that the Veteran worked primarily in jobs requiring physical labor and did not complete his high school education. Therefore, having considered the Veteran’s history, education, skill, and training along with his physical and psychiatric disabilities, the Board finds that the Veteran has been rendered unable to obtain and maintain a substantially gainful occupation due to limitations resulting from his service-connected disabilities for the periods prior to February 23, 2015; from April 1, 2015 to October 5, 2015; from December 1, 2015 to July 18, 2018; and since July 19, 2019. From November 1, 2018 to July 18, 2019 The Board has assigned the Veteran a total schedular rating for his right knee disability from November 1, 2018 to July 18, 2019, and, as discussed below, the Board is also granting SMC under 38 U.S.C. § 1114(s) for that period. Therefore, the Veteran’s benefits have been maximized, and the claim for TDIU for the period is moot. See Buie v. Shinseki, 24 Vet. App. 242, 250 (2011); Bradley v. Peake, 22 Vet. App. 280, 294 (2008). 4. SMC at the Housebound Rate The Veteran is also entitled to SMC at the housebound rate as set forth in 38 U.S.C. § 1114(s) for the period from November 1, 2018 to July 18, 2019. The VA has a ‘well-established’ duty to maximize a claimant’s benefits. See Buie v. Shinseki, 24 Vet. App. 242, 250 (2011); AB v. Brown, 6 Vet. App. 35, 38 (1993); see also Bradley v. Peake, 22 Vet. App. 280 (2008). This duty to maximize benefits requires VA to assess all a claimant’s disabilities to determine whether any combination of disabilities establishes entitlement SMC under 38 U.S.C. § 1114. See Bradley, 22 Vet. App. 280, 294 (2008). SMC is payable at the housebound rate where the Veteran has a single service-connected disability rated as 100 percent and, in addition: (1) has a service-connected disability or disabilities independently ratable at 60 percent, separate and distinct from the 100 percent service-connected disability, and involving different anatomical segments or bodily systems, or (2) is permanently housebound by reason of service-connected disability or disabilities. 38 U.S.C. § 1114 (s); 38 C.F.R. § 3.350 (i). In accordance with the above decision, the Veteran has been awarded a 100 percent rating for his right knee disability from November 1, 2018 to July 18, 2019. The record also demonstrates that the Veteran’s service-connected psychiatric disorder has been rated as 70 percent disabling for the entire rating period. Therefore, because the Veteran has a single service-connected disability rated at 100 percent and an additional service-connected disability independently rated as 70 percent disabling, that entitlement to SMC at the housebound rate under 38 U.S.C. § 1114 (s) is warranted for the period from November 1, 2018 to July 18, 2019. Finally, although TDIU may satisfy the “rated as total” element of section 1114(s), TDIU based on multiple underlying disabilities cannot satisfy the section 1114(s) requirement of “a service-connected disability” because that requirement must be met by a single disability. Buie v. Shinseki, 24 Vet. App. 242, 250 (2010). Here, as discussed above, the grant of TDIU is based on more than one service-connected disability, not a single disability as required by Buie. As such, the Veteran is not entitled to SMC at the housebound rate for any periods other than those during which he was in receipt of a temporary total ratings for his service-connected right knee disability. DONNIE R. HACHEY Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board E. Mine 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.