Citation Nr: 21011925 Decision Date: 03/03/21 Archive Date: 03/03/21 DOCKET NO. 09-47 717 DATE: March 3, 2021 ORDER From April 1, 2012, to August 18, 2020, entitlement to a disability evaluation in excess of 30 percent for service-connected residuals of left knee injury, status post arthroplasty is denied. From August 19, 2020, forward, entitlement to a disability evaluation in excess of 60 percent for service-connected residuals of left knee injury, status post arthroplasty is denied. Entitlement to a separate 20 percent disability evaluation, but no higher, for left knee instability from October 8, 2019, forward is granted. Entitlement to a total disability evaluation based on individual unemployability (TDIU) from December 4, 2019, forward is granted. REMANDED Entitlement to an initial disability evaluation in excess of 10 percent for service-connected residuals of left knee injury is remanded. Entitlement to a total disability evaluation based on individual unemployability (TDIU) prior to December 4, 2019, is remanded. FINDINGS OF FACT 1. The Veteran’s residuals of left knee injury, status post arthroplasty, manifested by chronic residuals consisting of intermediate degrees of residual weakness, pain or limitation of motion from April 1, 2012 to August 18, 2020, and by chronic residuals consisting of severe painful motion or weakness in the affected extremity since August 19, 2020. 2. A schedular rating higher than 60 percent for residuals of the Veteran’s left knee injury, status post arthroplasty since August 19, 2020, is not available as a matter of law. 3. From October 8, 2019, forward, the Veteran’s residuals of left knee injury, status post arthroplasty, manifested by moderate instability of the left knee. 4. The Veteran’s service-connected residuals of left knee injury, status post arthroplasty, painful scar of the left knee associated with residuals of left knee injury, status post arthroplasty, and right knee degenerative joint disease associated with residuals of left knee injury, status post arthroplasty, prevented him from obtaining or maintaining substantially gainful employment from December 4, 2019, forward. CONCLUSIONS OF LAW 1. The criteria for a disability evaluation in excess of 30 percent for residuals of left knee injury, status post arthroplasty, from April 1, 2012, to August 18, 2020, have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.321, 4.1, 4.3, 4.6, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5055. 2. A schedular rating higher than 60 percent for residuals of left knee injury, status post arthroplasty, from August 19, 2020, forward, is not available under the rating schedule. 38 U.S.C. § 1155; 38 C.F.R. § 4.71a, Diagnostic Code 5055. 3. The criteria for a separate disability evaluation of 20 percent, but no higher, for left knee instability from October 8, 2019, have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.321, 4.1, 4.3, 4.6, 4.7, 4.40, 4.45, 4.59, 4.71a, Diagnostic Code 5257. 4. The criteria for a TDIU from December 4, 2019, forward, have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.340, 3.341, 4.15, 4.16, 4.19. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from June 1976 to October 1980. This matter again comes before the Board of Veterans’ Appeals (Board) on appeal from a February 2009 rating decision issued by the Department of Veterans Affairs (VA) Regional Office (RO) in San Diego, California. As a preliminary matter, the Board acknowledges that in February 2011, the Veteran underwent a total knee replacement of the left knee. As a result, in June 2011, the agency of original jurisdiction (AOJ) granted an evaluation of 100 percent for his left knee disability effective February 25, 2011. An evaluation of 30 percent under Diagnostic Code (DC) 5055 was assigned from April 1, 2012. In October 2020, the AOJ issued a rating decision granting a 60 percent disability evaluation under DC 5055 for the Veteran’s left knee disability effective August 19, 2020. The Board previously remanded this matter in September 2013 and December 2017. 1. From April 1, 2012, to August 18, 2020, entitlement to a disability evaluation in excess of 30 percent for service-connected residuals of left knee injury, status post arthroplasty is denied. 2. From August 19, 2020, forward, entitlement to a disability evaluation in excess of 60 percent for service-connected residuals of left knee injury, status post arthroplasty is denied. Disability evaluations are determined by evaluating the extent to which a veteran’s service-connected disability adversely affects his or her ability to function under the ordinary conditions of daily life by comparing his or her symptomatology with the criteria set forth in the Schedule for Rating Disabilities. The percentage ratings represent as far as can practicably be determined the average impairment in earning capacity in civilian occupations resulting from such diseases and injuries, and their residual conditions. Generally, the degrees of disability specified are considered adequate to compensate for considerable loss of working time from exacerbation or illness proportionate to the severity of the several grades of disability. 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Separate DCs identify various disabilities and the criteria for specific ratings. If two disability evaluations are potentially applicable, the higher evaluation will be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. 38 C.F.R. § 4.7. Any reasonable doubt regarding the degree of disability will be resolved in favor of the veteran. 38 C.F.R. § 4.3. A veteran’s entire history is reviewed when making a disability determination. 38 C.F.R. § 4.1. When the factual findings show distinct time periods during which a claimant exhibits symptoms of the disability at issue and such symptoms warrant different evaluations, stage evaluations may be assigned. See Hart v. Mansfield, 21 Vet. App. 505 (2007). Under 38 C.F.R. § 4.59, painful motion is an important factor of joint disability and painful joints are entitled to at least the minimum compensable rating for the joint. Where functional loss is alleged due to pain upon motion, the provisions of 38 C.F.R. § 4.40 and § 4.45 must be considered. DeLuca v. Brown, 8 Vet. App. 202, 207-08 (1995). Pain itself does not rise to the level of functional loss contemplated by the VA regulations applicable to the musculoskeletal system unless it limits the ability to perform the normal working movements of the body with normal excursion, strength, coordination, or endurance. Mitchell v. Shinseki, 25 Vet. App. 32, 43 (2011). Under DC 5055, a 100 percent evaluation is assigned for one year following implantation of a knee prosthesis. After one year, a minimum 30 percent evaluation is assigned. A maximum 60 percent is assigned for chronic residuals consisting of severe painful motion or weakness in the affected extremity. Intermediate degrees of residual weakness, pain, or limitation of motion may be rated by analogy to Codes 5256, 5261, or 5262. The words “intermediate” and “severe” as used in the various diagnostic codes are not defined in the VA Schedule for Rating Disabilities. Rather than apply 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. It should also be noted that the use of terminology such as “severe” by VA examiners and others, although not an element to be considered by the Board, is not dispositive of an issue. All evidence must be evaluated in arriving at a decision regarding an increased rating. 38 C.F.R. §§ 4.2, 4.6. Normal range of motion for the knee is from 0 degrees of extension to 140 degrees of flexion. See 38 C.F.R. § 4.71, Plate II. The Veteran underwent a total left knee replacement in February 2011. Since that time, the Veteran has reported consistent left knee pain. During a November 2012 examination, the Veteran stated that his left knee was improving; however, there was still swelling especially at the back of the knee. He reported experiencing flare-ups of the knee approximately twice a week lasting for about 10-15 minutes. He informed the examiner that prolonged sitting for more than 40 minutes caused stiffness and that when getting up he had to wait for a minute before taking off. His flare-ups were precipitated by going up stairs, standing for more than an hour, kneeling, bending, or walking more than a block. Initially, the Veteran’s range of motion measured from 0 degrees of extension to 70 degrees of flexion. He exhibited painful motion and on repetitive use testing, no change was documented in the Veteran’s range of motion. The examiner noted painful motion both during initial range of motion measurements and after repetitive use testing in addition to swelling on the left knee and pain on palpation on the joint line or soft tissues of the left knee. The Veteran’s muscle strength was noted as mildly weakened at 4/5 (active movement against some resistance); however, no muscle atrophy was documented. The examiner concluded that the Veteran’s joint stability of the left knee was normal. The November 2012 examiner found that the Veteran’s residuals from his total left knee joint replacement manifested by intermediate degrees of residual weakness, pain, or limitation of motion. The Veteran also reported constant use of a brace and regular use of a cane due to his left knee condition. Additionally, the examiner concluded that the Veteran’s condition impacted his ability to work in that it prevented him from walking too fast and made it difficult for him to walk around because of knee pain and fear of falling. When the Veteran was examined again in October 2019, during which time he reported continued left knee pain with difficulty walking and standing. When asked about flare-ups, he stated that he experienced flare-ups approximately 2-3 times per month, with moderate and sometimes severe pain levels. He informed the examiner that he avoided deep bending, stooping, squatting, kneeling, crawling, climbing, prolonged standing, prolonged walking, jogging, and moderate to heavy lifting, pushing and pulling. Initially, the Veteran’s left knee range of motion measured from 0 degrees of extension to 100 degrees of flexion which had not changed after repetitive use testing, reflecting that the Veteran’s range of motion had significantly improved since the November 2012 examination. The examiner noted pain on both flexion and extension and that there is anterior and distal tenderness which were mild to palpation and some posterior lateral tenderness of the left knee without swelling or asymmetry but that there was no objective evidence of crepitus of the left knee. Although the Veteran was not being examined immediately after repetitive use over time, the examiner found that neither pain, weakness, fatigability, nor incoordination would significantly limit the Veteran’s functional ability with repeated use over a period of time. When evaluating the Veteran’s flare-ups, the examiner concluded that even though the examination was not conducted during a flare-up, pain and fatigue would significantly limit the Veteran’s functional ability with flare-ups and estimated that the Veteran’s range of motion during a flare-up based on the information elicited from the Veteran would be from 0 degrees of extension to 100 degrees of flexion. The examiner found the Veteran’s left knee muscle strength to be normal and that the Veteran did not exhibit muscle atrophy. However, as discussed below, the examiner documented moderate instability of the left knee. In determining the severity of the Veteran’s total knee replacement residuals, the examiner concluded that the Veteran’s residuals manifested to an intermediate degree of residual weakness, pain, or limitation of motion. Additionally, the Veteran reported constant use of a walker for support of the left knee with standing and ambulation. When reviewing recent imaging reports, the examiner noted that the left knee had a stable appearance and no sign of hardware failure. The examiner also noted that the Veteran’s left knee condition impacts his ability to work. Specifically, the Veteran “[s]hould avoid deep bending, stooping, squatting, kneeling, crawling, climbing, prolonged standing, prolonged walking, jogging, and moderate to heavy lifting, pushing, and pulling.” The Veteran was examined again in August 2020, during which time he stated that his knee has been painful and that he reported flare-ups; however, the examiner did not elicit from the Veteran further information as to the duration, frequency, precipitating, or alleviating factors of his flare-ups. However, the Veteran reported that during a flare-up he experiences more pain. He also told the examiner that it was difficult to walk. Initially, the range of motion of the left knee measured from 0 degrees of extension to 90 degrees of flexion. Pain was noted on flexion and extension and the Veteran exhibited moderate to severe tenderness to the left knee in addition to evidence of pain with weight bearing and crepitus. On repetitive use testing, the Veteran’s range of motion did not change. Although the Veteran was not being examined immediately after repetitive use over time, the examiner concluded that pain significantly limits the Veteran’s functional ability. Furthermore, when evaluating the Veteran’s reports of flare-ups, the examiner found that pain significantly limits his functional ability during flare-ups and that even though his extension would not change, his flexion would decrease to 80 degrees. The August 2020 examiner noted that the Veteran’s muscle strength mildly weakened to 4/5 (active movement against some resistance) since his October 2019 examination; nevertheless, the Veteran did not exhibit any muscle atrophy. Again, as discussed below, the Veteran exhibited moderate left knee instability. When determining the severity of the Veteran’s left knee total joint replacement, the examiner concluded that his residuals consisted of chronic severe painful motion or weakness. The Veteran also noted regular use of a walker as an assistive device. The August 2020 examiner found that the Veteran’s left knee disability impacted his ability to work. Specifically, it would be hard for him to walk, sit, stand, kneel, and squat while working. At the Veteran’s most recent examination in September 2020, he informed the examiner that his knee has been painful but did not report flare-ups. Nevertheless, he noted that he could not stand up without holding onto something and that he uses a walker. Initially, the Veteran’s left knee range of motion measured from 0 degrees of extension to 100 degrees of flexion. The examiner did not find any objective evidence of localized tenderness or pain on palpation but found evidence of pain with weight bearing. After repetitive use testing, the Veteran’s range of motion did not change. However, when evaluating the Veteran’s statements regarding repeated use over a period of time, the examiner concluded that although the Veteran’s extension would not change, his flexion would decrease to 90 degrees. The Veteran’s muscle strength had not decreased since the August 2020 examination and again no muscle atrophy was observed. The September 2020 examiner found that the Veteran did not exhibit joint instability; however, as discussed below, the Board finds the August 2020 examination to be more probative as to the consistent presence of left knee instability, entitling the Veteran to a separate evaluation. The September 2020 agreed with the August 2020 examiner that the Veteran’s residuals from his left knee total joint replacement manifested by chronic residuals consisting of severe painful motion or weakness. The Veteran was noted to regularly use a brace and walker as assistive devices due to his left total knee arthroplasty. Finally, when evaluating whether the Veteran’s left knee condition impacts his ability to work, the examiner concluded that the Veteran “should avoid employment or vocations that require prolonged standing or weight bearing ambulation, as this could exacerbate [his] symptoms or worsen [his] condition. Additionally [he] should be accommodated with having use of a chair as needed while working.” The AOJ granted a 30 percent evaluation from April 1, 2012, to August 19, 2020 based on this evaluation being the minimum rating available after one year from prosthetic replacement from the knee joint. As noted above, the Veteran’s residuals from his total left knee arthroplasty were found to manifest by intermediate degrees of weakness, pain, or limitation of motion during his November 2012 examination. There is no evidence of record indicating that the Veteran’s residuals manifested of chronic severe painful motion or weakness in the affected extremity prior to the Veteran’s August 2020 examination. The Board notes that the Veteran’s medical records between April 2012 and August 2020 have shown reports of painful motion. However, the Board recognizes that his range of motion of the left knee did not satisfy the criteria for a compensable rating under DCs 5260 and 5261. While limitation of motion may be a factor in the inquiry, “severe painful motion” under DC 5055 and limitation of motion are “distinct concepts.” Tedesco v. Wilkie, 2019 U.S. Vet. App. no. 18-180. Thus, the determination of whether severe painful motion exists for purposes of assigning a 60 percent disability evaluation under DC 5055 may not be based solely on range of motion testing results. Id. Here, the credible evidence of chronic intermediate pain and weakness supports a 30 percent evaluation prior to August 19, 2020. Additionally, the competent credible evidence supports a 60 percent disability evaluation from August 19, 2020, forward. The August 2020 examination is the first noted instance of the Veteran’s residuals from his left total knee arthroplasty manifested by chronic residuals consisting of severe painful motion or weakness in the affected extremity. A 60 percent rating is the maximum schedular rating available for residuals of a knee replacement beyond the one-year period following the replacement and any convalescent period. See 38 C.F.R. § 4.71a, DC 5055. Therefore, a rating in excess of 60 percent from August 19, 2020, forward is not warranted. See Sabonis v. Brown, 6 Vet. App. 426, 430 (1994). To summarize, the Board finds that disability evaluations in excess of 30 percent from April 1, 2012, to August 18, 2020, and in excess of 60 percent from August 19, 2020, forward, for the Veteran’s residuals of left knee injury, status post total knee arthroplasty, are not warranted. 3. Entitlement to a separate 20 percent disability evaluation, but no higher, for left knee instability from October 8, 2019, forward is granted. As the criteria under DC 5055 do not address instability, separate rating under Code 5257 is permissible. See generally VAOPCGPREC 23-97 and VAOPGCREC 9-98; 38 C.F.R. § 4.14. Diagnostic Code 5257 provides for assignment of a 10 percent rating when there is slight recurrent subluxation or lateral instability, a 20 percent rating when there is moderate recurrent subluxation or lateral instability, or a 30 percent evaluation for severe knee impairment with recurrent subluxation or lateral instability. Here, the Veteran first reported one instance of his knee “giv[ing] out” during an April 2012 visit to his primary care physician. See April 2012 VA Primary Care E&M Note. However, the Veteran did not report instances of knee buckling or instability again until May 2018. See May 2018 VA Homeless Program Note. He then did not report instability until February 2019. See February 2019 VA Homeless Program Note. When he presented again at the VA, he stated that his knee pain had increased that it would buckle “at times.” See April 2019 VA Homeless Program Note. The Veteran again stated that he had been falling and experiencing knee buckling in May 2019 and July 2019. See May 2019 VA Neuropsychological Evaluation; July 2019 VA Mental Health Initial Evaluation Note. On examination in October 2019, the examiner found that the Veteran’s file noted a history of lateral instability of the left knee. When performing stability testing, the examiner concluded that the Veteran’s left knee exhibited 2+ (5-10 millimeters) of anterior instability, medial instability, and lateral instability, indicating a moderate severity. During a December 2019 physical medicine rehabilitation appointment, the Veteran stated that he had difficulty ambulating longer distances and had fallen but had not experienced significant injuries as a result of falling. See December 2019 VA Physical Medicine Rehab Physician Note. The Veteran’s left knee was again evaluated in August 2020, during which the examiner concluded that the Veteran’s instability of the left knee had not changed since the October 2019 examination. However, when the Veteran was examined again in September 2020, the examiner concluded that he exhibited normal joint stability of the left knee. The September 2020 examiner found that there was no history of instability of the Veteran’s left knee, even though instability was reported in the Veteran’s 2019 VA medical records and the August 2020 examiner found such a history after reviewing the Veteran’s claims file. Here, as there is both positive and negative evidence demonstrating moderate instability of the left knee, the Board finds that the evidence is at least in equipoise, and that even considering the September 2020 findings, affording the Veteran the benefit of the doubt, instability is ascertained by the evidence. Therefore, the Board finds that, in light of the competent objective medical evidence documenting moderate instability from October 8, 2019, forward, the Veteran is entitled to a separate disability evaluation for left knee instability under Diagnostic Code 5257. 4. Entitlement to a TDIU from December 4, 2019, forward is granted. Total disability ratings for compensation may be assigned, where the schedular rating is less than 100 percent, when the disabled person is, in the judgment of the rating agency, unable to secure or follow a substantially gainful occupation as a result of one or more service-connected disabilities without regard to advancing age or nonservice-connected disabilities. 38 C.F.R. §§ 3.340, 3.341(a), 4.16(a), 4.19; Hatlestad v. Brown, 5 Vet. App. 524, 529 (1993) (holding that the central inquiry is whether the Veteran’s service-connected disabilities alone are of sufficient severity to produce unemployability). The claimant’s service-connected disabilities, employment history, educational and vocational attainment, and all other factors having a bearing on the issue must be considered. 38 C.F.R. § 4.16(b). Total disability will be considered to exist 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. § 4.15. While the rating is based primarily upon the average impairment in earning capacity, full consideration must be given to unusual physical or mental effects in individual cases, to peculiar effects of occupational activities, to defects in physical or mental endowment preventing the usual amount in success in overcoming the handicap of disability, and to the effect of combinations of disability. Id. Substantially gainful employment is defined as work which is more than marginal, and which permits the individual to earn a living wage. 38 C.F.R. § 4.16(a). Marginal employment may also be established, on a facts-found basis, when earned annual income exceeds the poverty threshold, including but not limited to employment in a protected environment such as a family business or sheltered workshop. Id. Consideration must be given in all claims to the nature of the employment and the reason for termination. Id. Although the Board must give full consideration to “the effect of combinations of disability” under 38 C.F.R. § 4.15, “neither the statute nor the relevant regulations require the combined effect to be assessed by a medical expert.” Geib v. Shinseki, 733 F.3d 1350, 1354 (Fed. Cir. 2013). Indeed, regulation places responsibility for the ultimate determination of unemployability on the Board or rating agency, not a medical examiner. Id. (citing 38 C.F.R. § 4.16(a)). As part of this ultimate determination, VA is required to obtain a medical examination or opinion only when “necessary to make a decision on the claim.” Id. (citing 38 U.S.C. § 5103A(d)(1)). Where separate medical opinions address the impact on employability resulting from independent disabilities, the Board is authorized to assess the aggregate effect of all disabilities. Id. Certain percentage requirements must be satisfied to qualify for schedular consideration of entitlement to TDIU. Specifically, if unemployability is the result of only one service-connected disability, this disability must be ratable at 60 percent or more. 38 C.F.R. § 4.16(a). If it is the result of two or more service-connected disabilities, at least one must be ratable at 40 percent or more, with the others sufficient to bring the combined rating to 70 percent or more. Id. Disabilities of one or both upper extremities, or one or both lower extremities, including the bilateral factor, disabilities resulting from a common etiology or a single accident, and disabilities affecting a single body system such as orthopedic disabilities, will be considered as one disability for TDIU purposes. Id. In light of the Board’s above decision granting entitlement to a separate evaluation for left knee instability effective October 8, 2019, the Veteran’s compensable service-connected conditions effective December 4, 2019 (the effective date of his service-connected painful scars and right knee disability), are evaluated as follows: residuals of left knee injury, status post arthroplasty as 30 percent disabling (increased to 60 percent disabling effective August 19, 2020); painful scar of the left knee associated with residuals of left knee, status post arthroplasty as 20 percent disabling; right knee degenerative joint disease associated with residuals of left knee injury, status post arthroplasty as 10 percent disabling. When combined, including the bilateral factor, the Veteran’s disabilities are evaluated at 60 percent disabling effective December 4, 2019. Thus, the criteria for schedular consideration of TDIU from December 4, 2019, forward, are satisfied. 38 C.F.R. § 4.16(a). Probative evidence also reflects that the Veteran’s service-connected disabilities caused a significant impairment on his ability to work. The August 2020 examiner found that the Veteran’s left knee condition made it hard to walk, sit, stand, kneel, and squat while working. Furthermore, the September 2020 examiner concluded that the Veteran should be accommodated in a working environment with having the use of a chair as needed and that he should avoid employment or vocations that require prolonged standing or weight bearing ambulation. The Board finds that the September 2020 examiner’s conclusion indicates that the Veteran would only be able to work marginally, as accommodations or a protected environment would be required. Moreover, the Veteran’s records as furnished by the Social Security Administration (SSA) reflect that the Veteran has been receiving disability benefits due to his service connected “fracture of lower limb” and “osteoarthritis and allied disorders” in his knees. See January 2009 Disability Determination and Transmittal (received in January 2018). In his application for SSA disability benefits, the Veteran noted that he previously worked in positions that required prolonged walking, standing, climbing, stooping, kneeling, and crouching. See October 2009 SSA Work History Report (received in January 2018). Resolving reasonable doubt in favor of the Veteran, the Board finds that his service-connected knee disabilities have resulted in unemployability, based on the evidence discussed above. Given the Veteran’s symptoms and noted functional impairment due to his service-connected bilateral knee conditions from December 4, 2019, forward, and receipt of SSA benefits due to his bilateral knee disabilities, the Board affords the Veteran the benefit of the doubt and finds that his service-connected residuals of left knee injury, status post arthroplasty; painful scar of the left knee associated with residuals of left knee injury, status post arthroplasty; and right knee degenerative joint disease associated with residuals of left knee injury, status post arthroplasty satisfy the criteria for TDIU from December 4, 2019, forward. See 38 C.F.R. §§ 3.102, 4.16(a); Wise v. Shinseki, 26 Vet. App. 517, 531 (2014) (“By requiring only an ‘approximate balance of positive and negative evidence’ the Nation, ‘in recognition of our debt to our veterans’ has ‘taken upon itself the risk of error’ in awarding . . . benefits.”). REASONS FOR REMAND 1. Entitlement to an initial disability evaluation in excess of 10 percent for service-connected residuals of left knee injury is remanded. Regarding the Veteran’s claim for an initial disability evaluation in excess of 10 percent for his service-connected residuals of left knee injury prior to his February 2011 total knee arthroplasty, the Board notes that during the Veteran’s examination in February 2009, he stated that “by being careful” he would avoid flare-ups of the left knee and that stairs were difficult for him. In the years since this examination, the United States Court of Appeals for Veterans Claims (Court) has ruled that examiners must describe functional loss in terms of additional range of motion loss due to pain on use or flare-ups or provide an approximate estimate, per the Veteran, to what extent, if any, they affect functional impairment. Sharp v. Shulkin, 29 Vet. App. 26 (2017). Because this examination does not contain any such measurements or estimates, the Board requests an opinion as to the Veteran’s flare-ups as experienced prior to his February 2011 left total knee arthroplasty. See Chotta v. Peake, 22 Vet. App. 80 (2008) (when there is an absence of medical evidence during a certain time period, a retrospective medical evaluation may be warranted). 2. Entitlement to a TDIU prior to December 4, 2019, is remanded. As a preliminary matter, the Board notes that the Veteran’s claim for an initial disability evaluation in excess of 10 percent for his service-connected residuals of a right knee injury prior to his February 2011 left total knee arthroplasty and claim for entitlement to TDIU are inextricably intertwined. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991) (two issues are “inextricably intertwined” when they are so closely tied together that a final Board decision cannot be rendered unless both issues have been considered). Consequently, as the Veteran’s claim of entitlement to an initial disability evaluation in excess of 10 percent for residuals of a right knee injury must be remanded, so too must the Veteran’s claim for entitlement to a TDIU prior to December 4, 2019. Furthermore, in light of the Board’s above-mentioned decision of granting entitlement to a separate evaluation of 20 percent for left knee instability, prior to December 4, 2019, the Veteran’s service-connected disabilities still do not meet the schedular criteria for consideration of a TDIU. VA regulations provide that if a Veteran fails to meet the applicable percentage standards enunciated in 38 C.F.R. § 4.16(a), rating boards should refer to the Director of Compensation and Pension Service for extraschedular consideration all cases where the Veteran is unable to secure or follow a substantially gainful occupation by reason of a service-connected disability. 38 C.F.R. § 4.16(b); see also Fanning v. Brown, 4 Vet. App. 225 (1993). Only after the Director has determined whether an extraschedular evaluation is warranted does the Board have jurisdiction to decide the merits of the extraschedular aspect of the TDIU claim. The AOJ has, thus far, declined to refer the Veteran’s claim to the Director despite the above-mentioned probative evidence that his service-connected knee conditions prevent him from obtaining and maintaining substantially gainful employment. Considering the evidence of record as well as the January 2009 SSA Disability Determination, such evidence reasonably raises the possibility that the Veteran could not work due to his service-connected disabilities prior to December 4, 2019. The Board therefore, in the event that after a retrospective opinion, if any, is obtained as to the nature and severity of the Veteran’s residuals of left knee injury does not cause an increase in evaluation that would warrant schedular consideration of TDIU, refers the Veteran’s claim of entitlement to a TDIU due to service-connected disabilities to the Undersecretary for Benefits or Director of Compensation and Pension service for an extraschedular evaluation under 38 C.F.R. § 4.16(b) for the period prior to December 4, 2019. The matters are REMANDED for the following action: 1. Forward the claims file to an appropriate clinician for a medical opinion, if possible and as best as can be ascertained from the Veteran’s self-reports as well as from clinical records and other evidence, including VA examination reports, as to the severity, frequency, and duration of any flare-ups of the Veteran’s service-connected residuals of left knee injury prior to left total knee arthroplasty in February 2011, and the degree of functional loss during said flare-ups. If it is not possible to provide a specific measurement, or an opinion regarding flare-ups, symptoms without speculation, the clinician must state whether the need to speculate is due to a deficiency in the state of general medical knowledge (no one could respond given the medical science and known facts), a deficiency in the record (additional facts are required), or the examiner (does not have the knowledge or training. 2. Readjudicate the Veteran’s claim for entitlement to an initial disability evaluation in excess of 10 percent for his service-connected residuals of left knee injury prior to left total knee arthroplasty. (Continued on the next page)   3. If, after readjudication of the Veteran’s claim for entitlement to an initial disability evaluation in excess of 10 percent for his service-connected residuals of left knee injury prior to left total knee arthroplasty, the Veteran’s combined disability evaluation continues to not meet the schedular criteria for consideration of a TDIU for the period prior to December 4, 2019, refer the claim of entitlement to a TDIU to the Director, Compensation and Pension Service for extraschedular consideration under 38 C.F.R. § 4.16(b) for the period prior to December 4, 2019. Zi-Heng Zhu Acting Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board S. Seserman 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.