Citation Nr: 21072986 Decision Date: 12/07/21 Archive Date: 12/07/21 DOCKET NO. 06-11 535 DATE: December 7, 2021 ORDER Entitlement to a rating in excess of 10 percent for right knee retropatellar arthrosis is denied. Entitlement to a compensable rating for right knee limitation of extension is denied. Entitlement to a rating of 10 percent, but no higher, for right knee arthritis based on limitation of flexion, for the entire time period on appeal, is granted. REMANDED Entitlement to an evaluation in excess of 20 percent for lumbar degenerative changes with low back strain, effective April 8, 2007, is remanded. Entitlement to TDIU prior to March 7, 2016, is remanded. FINDINGS OF FACT 1. Over the entire appeal period, the Veteran had occasional occurrences of her right knee buckling, indicating no more than a slight level of right knee instability. 2. Over the entire appeal period on appeal, the Veteran's right knee extension was limited to no more than 5 degrees, to include during flare-ups and after repetitive use. 3. Over the entire appeal period, the Veteran's right knee disability was manifested by arthritis, with painful motion in flexion; but flexion has not been limited to 45 degrees or less, to include during flare-ups and after repetitive use. CONCLUSIONS OF LAW 1. The criteria for a rating in excess of 10 percent for right knee retropatellar arthrosis have not been met. 38 U.S.C. § 1155; 38 C.F.R. §§ 4.1, 4.2, 4.40, 4.45, 4.59, 4.71a, DC 5257. 2. The criteria for a compensable rating for right knee limitation of motion in extension have not been met. 38 U.S.C. § 1155; 38 C.F.R. §§ 4.1, 4.2, 4.40, 4.45, 4.59, 4.71a, DC 5261. 3. The criteria for a 10 percent rating for right knee arthritis with painful motion in flexion have been met during the entire appeal period. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.2, 4.3, 4.40, 4.45, 4.59, 4.71a, DC 5003, 5260. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from October 1975 to June 1996. This matter comes before the Board of Veterans' Appeals (Board) on appeal from rating decisions issued by a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran testified at a hearing before the undersigned in June 2014. This matter has a complicated procedural history which has been addressed in prior Board remands. This matter was most recently remanded by the Board in September 2020. The case has been returned to the Board at this time for further appellate review. The case was last remanded, in part, to obtain a VA examination to determine the current nature and severity of the Veteran's right knee disability. VA examinations were provided in February and July 2021 that comply with the September 2020 Board remand. Accordingly, the Board finds there was substantial compliance with the prior remand directives. In May 2013, the Board took jurisdiction over the issue of entitlement to TDIU pursuant to Rice v. Shinseki, 22 Vet. App. 447 (2009). A February 2018 rating decision granted entitlement to TDIU effective March 7, 2016. However, because entitlement to TDIU was raised prior to March 2016 pursuant to Rice, the issue of entitlement to TDIU prior to March 7, 2016 remains on appeal. Increased Rating 1. Entitlement to a rating in excess of 10 percent for right knee retropatellar arthrosis is denied. 2. Entitlement to a compensable rating for right knee limitation of extension is denied. 3. Entitlement to a rating of 10 percent, but no higher, for right knee arthritis based on limitation of flexion, for the entire time period on appeal, is granted. Disability ratings are determined by applying the criteria set forth in VA's Schedule for Rating Disabilities, which is based on the average impairment of earning capacity. Individual disabilities are assigned separate Diagnostic Codes (DCs). 38 U.S.C. § 1155; 38 C.F.R. § 4.1. Where there is a question as to which of two evaluations shall be applied, the higher evaluation will be assigned if the disability picture more nearly approximates the criteria for that rating. Otherwise, the lower rating will be assigned. See 38 C.F.R. § 4.7. Any reasonable doubt regarding a degree of disability will be resolved in favor of the veteran. 38 C.F.R. § 4.3. When the evidence is in relative equipoise, the veteran is accorded the benefit of the doubt. 38 U.S.C. § 5107(b). The Board must consider all the evidence of record and make appropriate determinations of competence, credibility, and weight. Wood v. Derwinski, 1 Vet. App. 190 (1991); Washington v. Nicholson, 19 Vet. App. 362 (2005). Where entitlement to compensation has already been established and increase in the disability rating is at issue, the present level of disability is of primary concern; therefore, the more critical evidence consists of the evidence generated during the appeal period. See Francisco v. Brown, 7 Vet. App. 55, 58 (1994). Yet, the Board must evaluate the medical evidence of record since the filing of the claim for increased rating and consider the appropriateness of a "staged rating" (i.e., assignment of different ratings for distinct periods of time, based on the facts). Hart v. Mansfield, 21 Vet. App. 505 (2007). 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). In Correia v. McDonald, 28 Vet. App. 158 (2016), the United States Court of Appeals for Veterans Claims (Court) held that the final sentence of 38 C.F.R. § 4.59 requires that the examiner record the results of range of motion testing "for pain on both active and passive motion [and] in weight-bearing and non-weight-bearing and, if possible, with range of motion measurements of the opposite undamaged joint." In Sharp v. Shulkin, 29 Vet. App. 26 (2017), the Court held that VA examiners must obtain information about the severity, frequency, duration, precipitating and alleviating factors, and extent of functional impairment of flare-ups from the veterans themselves, when a flare-up is not observable at the time of examination. Normal range of motion (ROM) of the knee is to zero (0) degrees (full extension ROM) to 140 degrees (full flexion ROM). 38 C.F.R. § 4.71a, Plate II. Under DC 5260, a noncompensable (0 percent) rating is warranted where flexion of the knee is limited to 60 degrees, and a 10 percent disability evaluation is warranted when flexion is limited to 45 degrees. A 20 percent disability rating is warranted when flexion is limited to 30 degrees, and a 30 percent rating is warranted when flexion of the leg is limited to 15 degrees. 38 C.F.R. § 4.71a, DC 5260. Under DC 5261, a noncompensable (0 percent) rating is warranted when extension of the knee is limited to 5 degrees, and a 10 percent disability rating is warranted when extension of the knee is limited to 10 degrees. A 20 percent disability rating is warranted when extension is limited to 15 degrees, and a 30 percent rating is warranted when extension limited to 20 degrees. A 40 percent disability rating is warranted when extension is limited to 30 degrees, and a 50 percent disability rating is warranted when extension of the leg is limited to 45 degrees. 38 C.F.R. § 4.71a, DC 5261. Under DC 5257 a disability rating may be assigned for subluxation or lateral instability of the knee. A 10 percent rating is warranted for slight recurrent subluxation or lateral instability. A 20 percent rating is warranted for moderate recurrent subluxation or lateral instability. A 30 percent rating is warranted for severe recurrent subluxation or lateral instability. 38 C.F.R. § 4.71a, DC 5257. According to MERRIAM WEBSTER'S COLLEGIATE DICTIONARY 999 (11th Ed. 2007), "slight" means small in amount. "Moderate" means limited in scope or effect. "Severe" means very painful or harmful or of a great degree. Objective medical evidence is not required to establish lateral knee instability under DC 5257, and objective medical evidence cannot be categorically found more probative than lay evidence with respect to this DC. See English v. Wilkie, 30 Vet. App. 347, 352-53 (2018). Under DC 5258, dislocation of the semilunar cartilage of the knee with frequent episodes of "locking," pain and effusion into the joint warrants a 20 percent disability rating. 38 C.F.R. § 4.71a, DC 5258. Under DC 5259, symptomatic removal of semilunar cartilage warrants a 10 percent evaluation. 38 C.F.R. § 4.71a, DC 5259. Separate ratings may be assigned for compensable limitation of both flexion and extension, or for limitation of motion and instability or subluxation of the knee, or meniscal pathology. However, a separate rating can only be assigned where additional compensable symptomatology is shown that is not duplicative of that used to assign another rating. 38 C.F.R. § 4.14; VAOPGCPREC 09-04 (2004), 69 Fed. Reg. 59990 (2004); VAOPGCPREC 23-97 (1997), 62 Fed. Reg. 63604 (1997); VAOPGCPREC 9-98 (1998), 63 Fed. Reg. 56704 (1998); Lichtenfels v. Derwinski, 1 Vet. App. 484 (1991). In Lyles v. Shulkin, 29 Vet. App. 107 (2017), the Court held that, as a matter of law, separate ratings are not precluded for limitation of motion (DCs 5003, 5260 and 5261), meniscal disability (DCs 5258 and 5259), and instability (DC 5257). During the pendency of the Veteran's claim and appeal, the criteria for rating musculoskeletal disabilities were changed by an amendment to the rating schedule that became effective on February 7, 2021. 85 Fed. Reg. 76, 453 (November 30, 2020). Diagnostic Code 5257 was amended to provide ratings for recurrent subluxation or lateral instability. A 10 percent rating is warranted for sprain, incomplete ligament tear, or complete ligament tear (repaired, unrepaired, or failed repair) causing persistent instability, without a prescription from a medical provider for an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A 20 percent rating is warranted for either (a) sprain, incomplete ligament tear, or repaired complete ligament tear causing persistent instability, and a medical provider prescribing a brace and/or assistive device (e.g., cane(s), crutch(es), walker) for ambulation; or (b) unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider prescribing either an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. A 30 percent rating is warranted for unrepaired or failed repair of complete ligament tear causing persistent instability and a medical provider prescribing both an assistive device (e.g., cane(s), crutch(es), walker) and bracing for ambulation. The amended Diagnostic Code 5257 also provides for ratings based on patellar instability. A 10 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability (with or without history of surgical repair) that does not require a prescription from a medical provider for a brace, cane, or walker. A 20 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for one of the following: a brace, cane, or walker. A 30 percent rating is warranted for a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for a brace and either a cane or a walker. Note [1] to DC 5257 states that for patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note [2] to DC 5257 states that a surgical procedure that does not involve repair of one or more patellofemoral components that contribute to the underlying instability shall not qualify as surgical repair for patellar instability (including, but not limited to, arthroscopy to remove loose bodies and joint aspiration. Diagnostic Code 5262, for impairment of the tibia and fibula, also changed, but is not applicable to this matter. The remaining DCs were unchanged by the February 2021 amendments. The Board will apply the new criteria for the period beginning February 7, 2021, if the new criteria are more beneficial to the Veteran than the prior version of the regulation. See Kuzma v. Principi, 341 F.3d 1327 (Fed. Cir. 2003) (regulations may not have retroactive effect unless their language specifies so). In January 2010, the Veteran filed a claim seeking an increased rating for her right knee disability. The Veteran was assigned a 10 percent rating for her right knee retropatellar arthrosis under DC 5299-5257, effective May 18, 2004. Hyphenated diagnostic codes are used when a rating under one code requires use of an additional diagnostic code to identify the basis for the evaluation assigned; the additional code is shown after the hyphen. 38 C.F.R. § 4.27. In this case, DC 5272 refers to subluxation or lateral instability of the knee, as previously discussed. The Veteran was also assigned a noncompensable rating for right knee limitation of extension under DC 5003-5261, effective July 13, 2021. A VA examination was provided to evaluate the claim in January 2010. The Veteran reported constant right knee pain, on average 8/10 in intensity, that was aggravated by standing. She also reported that her right knee would swell and buckle at times; but denied clicking or locking. The January 2010 VA examiner noted no gross deformity, small joint effusion, and tenderness to palpation over the medial joint line. On initial range of motion testing, full extension (to zero degrees) was observed, and flexion was limited to 90 degrees. There was no change to range of motion after three repetitions. No other range of motion testing or estimated limitations were listed. The VA examiner found no evidence of fatigue, weakness, or lack of endurance, and the anterior drawer, Lachman, and McMurray tests were negative. A March 2011 private treatment record reflects that the Veteran's right knee had full extension (to zero degrees) and flexion limited to 95 degrees. A November 2011 private treatment record reflects that the Veteran's right knee was had full extension (to zero degrees), but flexion was limited to 90 degrees due to pain. The private clinician also noted mild effusion as well as medial and lateral joint line tenderness, however, it was also noted that there was no instability. A December 2011 private treatment record noted the Veteran's right knee was enlarged and she experienced pain with range of motion. The private clinician noted that there was no effusion or instability. A January 2013 private treatment record notes that the Veteran received an injection for her right knee pain and was experiencing diffuse tenderness to palpation with mild effusion but no instability. The Veteran received an injection of Synvisc in her right knee in May 2013. A September 2013 private treatment record reflects mild swelling of the right knee medially as well as marked tenderness on palpation of the right knee medial and lateral joint line and pes anserinum, but no instability. The private clinician also found full extension (to zero degrees) of the right knee and flexion limited to 90 degrees with pain. November and December 2014 private treatment records reflect that the Veteran experienced pain with range of motion. As stated in previous Board remands, the January 2014 VA examination, and the March 2019 VA examination, as amended in July 2020, are inadequate for purposes of rating range of motion. However, the January 2014 VA examination reflects that the Veteran reported constant right knee pain, on average 7/10 in pain intensity, which was aggravated by standing and stairs, and that she experienced swelling and buckling of her right knee at times. The January 2014 VA examination report also notes no instability, subluxation/dislocation, meniscal conditions or surgery, or any other surgery of the right knee. The March 2019 VA examiner found that there was no ankylosis, instability, subluxation, recurrent effusion, or meniscal condition in regards to the Veteran's right knee. A January 2020 VA treatment record reflects that the Veteran complained of occasional buckling of her right knee. Another VA examination was provided in February 2021. At the time of this examination, the Veteran reported swelling and buckling of her right knee, at times, pain with palpation, difficulty walking, and pain when climbing up and down stairs. The Veteran reported flare-ups once a week lasting a few hours to an entire day. The Veteran reported that her flare-ups caused pain and swelling such that she could not walk, stiffness, tenderness to touch, and limited range of motion such that she could not bend, twist, or squat. On initial range of motion testing, the examiner observed full extension (to zero degrees) and flexion limited to 130 degrees. Pain was observed in extension and flexion. There was also objective evidence of pain on passive range of motion testing and in non-weight bearing. Moderate tenderness on palpation was also noted on the anterior and medical aspect of the right knee. There was evidence of pain with weight bearing, as well as crepitus. Range of motion testing after repetitive use resulted in full extension (to zero degrees) and flexion limited to 125 degrees. The examiner found that, with repeated use over time, pain and weakness would additionally limit the Veteran's functional ability. The examiner estimated that her range of motion would result in full extension (to zero degrees) with flexion limited to 120 degrees with repeated use over time. The examiner found that, during a flare-up, pain and weakness would additionally limit the Veteran's functional ability. The examiner estimated that her range of motion would result in full extension (to zero degrees) with flexion limited to 110 degrees during a flare-up. The VA examination report reflects a finding of no ankylosis, history of recurrent subluxation, history of lateral instability, joint instability, tibial or fibular impairment, or meniscal condition regarding the Veteran's right knee. Finally, a VA examination was provided in July 2021. At the time of the examination, the Veteran reported stiffness in the morning and intermittent pain. She did not report flare-ups of her right knee disability. The VA examiner noted that the Veteran's right knee disability resulted in difficulty walking and standing, an inability to run, and pain standing and moving from a standing to a sitting position. The Veteran did not report a history of instability, recurrent subluxation, or frequent effusion of her right knee. On initial range of motion testing, the examiner observed full extension (to zero degrees) and flexion limited to 90 degrees. Pain was observed in extension and flexion. Passive range of motion testing provided the same results. The examiner noted pain associated with weight bearing, active motion, and passive motion. Range of motion testing after repetitive use resulted in extension limited to 5 degrees and flexion limited to 85 degrees, caused by pain, fatigability, and lack of endurance. The clinician estimated no additional reduction in range of motion or functional ability with repeated use over time. As the Veteran reported no flares-ups the examiner did not provide any additional evaluation for flare-ups. The July 2021 VA examination report reflects no findings of ankylosis, recurrent subluxation, persistent instability, ligament tear, patellar instability, tibial or fibular impairment, or meniscal condition regarding the Veteran's right knee. Instability Over the entire appeal period, a 10 percent rating has been applied, by analogy, under DC 5257 for the Veteran's right knee right knee retropatellar arthrosis. The January 2010 VA examination reflects the Veteran's report that her right knee buckled at times, however, the stability testing performed was negative. November 2011, December 2011, January 2013, and September 2013 private treatment records reflect the private clinicians' finding of no instability of the Veteran's right knee. The January 2014 VA examination reflects the Veteran's report of buckling of her right knee at times, although no instability was found on examination. In a January 2020 VA treatment record the Veteran complained of occasional buckling of her right knee. The February 2021 VA examination also reflects the Veteran's report of buckling of her right knee at times, but again, no instability was found on examination. Finally, no instability was found on examination in July 2021. Throughout the entire appeal period, the Veteran has reported, at most, that her knee buckles at times. Although not required to establish lateral knee instability, the objective medical evidence of record does not establish right knee instability. Thus, the Board finds that the Veteran's is competent to report buckling of her right knee, establishing lateral instability. However, based on the Veteran's statements, as well as the medical evidence of record, the Board finds that the Veteran's right knee instability does not rise to the level of "moderate" at any time during the time period on appeal. Thus, a rating in excess of 10 percent for right knee retropatellar arthrosis, as rated by analogy under DC 5257 for instability, is not warranted. 38 C.F.R. § 4.71a, DC 5257. In denying a rating higher than 10 percent, the Board finds the benefit of the doubt doctrine is not applicable. 38 U.S.C. § 5107; 38 C.F.R. §§ 4.3. The Board notes that a rating in excess of 10 percent is not available under the amended rating criteria for DC 5257. Thus, consideration of these amended criteria is not required. See Kuzma, supra. Limitation of Motion When there is some limitation of motion of the specific joint or joints involved that is noncompensable (0 percent) under the appropriate diagnostic codes, Diagnostic Code 5003 provides a rating of 10 percent for each such major joint or group of minor joints affected by limitation of motion, to be combined, not added under Diagnostic Code 5003. Limitation of motion must be objectively confirmed by findings such as swelling, muscle spasm, or satisfactory evidence of painful motion. When there is limitation of motion of the specific joint or joints that is considered to be compensable (10 percent or higher) under the appropriate diagnostic codes, the compensable limitation of motion should be rated under the appropriate diagnostic codes for the specific joint or joints involved. 38 C.F.R. § 4.71a. Separate disability ratings are possible for arthritis with limitation of motion under Diagnostic Codes 5003 and instability of a knee under Diagnostic Code 5257. VAOPGCPREC 23-97. When X-ray findings of arthritis are present and a veteran's knee disability is rated under Diagnostic Code 5257, the veteran would be entitled to a separate compensable rating under Diagnostic Code 5003 if the arthritis results in noncompensable limitation of motion and/or objective findings or indicators of pain. VAOPGCPREC 9-98. Here, the evidence shows that, at all times over the appeal period, the Veteran's right knee range of motion in flexion was limited. Yet, her range of motion in flexion, including as estimated during flare-ups and after repetitive use was always greater than 45 degrees. Thus, a compensable rating under DC 5260 is not indicated. Osteoarthritis of the right knee, confirmed by x-ray imaging, was diagnosed in a March 2000 VA treatment record. Accordingly, a separate rating of 10 percent for arthritis of a major joint with otherwise noncompensable limitation of motion and objective finds of pain is warranted. The Board finds that the preponderance of the evidence is against a rating in excess of 10 percent for limitation of flexion for the Veteran's right knee as her right knee flexion has not been limited to 30 degrees or less at any time during the appeal. In denying a rating higher than 10 percent, the Board finds the benefit of the doubt doctrine is not applicable. 38 U.S.C. § 5107; 38 C.F.R. §§ 4.3. In addition, the Board acknowledges the effective date of an award of an increased evaluation can be assigned up to one year prior to the date of an increased rating claim if it is factually ascertainable that an increase in disability occurred during this period. 38 U.S.C. § 5110(a); 38 C.F.R. § 3.400. Here, the Veteran has not reported experiencing any definitive increase in disability in the year prior to her January 2010 increased rating claim, and there are no treatment records or examination reports that support any definitive increase in disability in the year prior to her January 2010 increased rating claim. As such, the Board finds there is not a factually ascertainable increase in disability in the one-year period prior to the Veteran's January 2010 increased rating claim. As to the Veteran's right knee extension, it was not limited to a compensable degree, at any point during the appeal period. See 38 C.F.R. § 4.71a, DC 5261. Specifically, the medical evidence of record establishes that the Veteran had full extension of her right knee during most of the time period on appeal, and only recently her right knee extension was limited to 5 degrees, even after consideration of additional impairment produced by pain, weakness, fatigue, or incoordination following repetitive movement and/or during flare-ups. Thus, a compensable rating for limitation of extension for the right knee is not warranted. In denying a compensable rating, the Board finds the benefit of the doubt doctrine is not applicable. 38 U.S.C. § 5107; 38 C.F.R. §§ 4.3. Additional Ratings The Board finds that additional ratings for the Veteran's right knee disability are not warranted. A rating under DC 5256 is not indicated because there is no evidence of ankylosis. There is no evidence of meniscal conditions or impairment of the tibia and fibula to warrant a rating under DCs 5258, 5259, and 5262. Finally, there is no evidence of genu recurvatum to warrant a rating under DC 5263. Extraschedular Consideration The Veteran's representative has cited to language regarding rating of disabilities on an extraschedular basis. See October 2021 Post-Remand Brief. Although no arguments were made as to the Veteran's entitlement to a rating for her right knee disability on an extraschedular basis, to the extent the Veteran is asserting she is entitled to a rating for her right knee disability on an extraschedular basis, consideration of an extraschedular rating requires a three-step inquiry. The first question is whether the schedular rating criteria adequately contemplate the veteran's disability picture. If the schedular evaluation does not contemplate the level of disability and symptomatology shown and is found inadequate, then the second inquiry is whether the exceptional disability picture exhibits other related factors, such as marked interference with employment or frequent periods of hospitalization. See Thun v. Peake, 22 Vet. App. 111 (2008). The first Thun element compares a claimant's symptoms to the rating criteria, while the second addresses the resulting effects of those symptoms. Thus, the first and second Thun elements, although interrelated, involve separate and distinct analyses. Yancy v. McDonald, 27 Vet. App. 484, 495 (2016). If the veteran's disability picture meets the second inquiry, then the third step is to refer the case to the Director of Compensation Services to determine whether an extraschedular rating is warranted. See Thun, 22 Vet. App. 111. In regard to the first element, comparison of the Veteran's symptoms and associated functional impairment does not show that the rating criteria are inadequate to describe her disability picture. The record shows that she has complaints and findings of pain, swelling, instability, tenderness on palpation, limited range of motion with pain, effusion, and stiffness. Diagnostic Codes 5256 to 5263 do not specifically list all the Veteran's symptoms; however, the Veteran has been rated for her right knee instability and arthritis of a major joint with limited range of motion and pain. For all musculoskeletal disabilities, the Rating Schedule contemplates functional loss, which may be manifested by, for example, decreased or abnormal excursion, strength, speed, coordination, or endurance. 38 C.F.R. § 4.40; Mitchell, 25 Vet. App. at 37. For disabilities of the joints in particular, the Rating Schedule specifically contemplates factors such as weakened movement; excess fatigability; pain on movement; disturbance of locomotion; and interference with sitting, standing, and weight bearing. 38 C.F.R. §§ 4.45, 4.59; Mitchell, 25 Vet. App. at 37. In summary, the schedular criteria for musculoskeletal disabilities contemplate a wide variety of manifestations of functional loss. Because the Rating Schedule was purposely designed to compensate for such functional effects of the Veteran's disabilities in all spheres of her daily life, including at work and at home, and given the variety of ways in which the Rating Schedule contemplates functional loss for musculoskeletal disabilities, the Board concludes that the schedular rating criteria reasonably describe the Veteran's disability picture. The threshold issue under Thun is thus not met, and further consideration of an extraschedular rating is not warranted. In sum, the Board finds that the Veteran is entitled to a separate rating of 10 percent, but no higher, for right knee arthritis based on limitation of flexion, for the entire appeal period. To that extent, the Veteran's appeal is granted. However, the Board finds that the preponderance of the evidence is against entitlement to a rating in excess of 10 percent for right knee retropatellar arthrosis and entitlement to a compensable rating for right knee limitation of extension, and to that extent, the appeal is denied. REASONS FOR REMAND 1. Entitlement to an evaluation in excess of 20 percent for lumbar degenerative changes with low back strain, effective April 8, 2007, is remanded. The Board finds that remand is warranted to clarify the diagnosis, if any, and severity of any neurological abnormalities, other than radiculopathy, associated with the Veteran's service-connected back disability as they are part and parcel of the Veteran's increased rating claim for her back disability. In this regard, the Board finds that the evidence of record is conflicting. Specifically, October 2006 and July 2014 VA treatment records note no incontinence, however, they also reflect that the Veteran's back pain makes her walk slowly, and therefore she is not always able to make it to the bathroom in time. A January 2020 VA treatment record notes urge incontinence. The February 2021 VA examiner initially noted that there were no other neurological abnormalities related to the Veteran's back disability, but later notes one remote incident of loss of bladder control during a flare-up of her back disability. The July 2021 VA examiner did not note any other neurological abnormalities related to the Veteran's back disability. The Board finds that remand is warranted to obtain clarification from a medical professional regarding this issue. 2. Entitlement to TDIU prior to March 7, 2016, is remanded. The issue of entitlement to TDIU is inextricably intertwined with the increased rating claim for the Veteran's service-connected back disability, and thus is remanded. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991) (holding that where a decision on one issue would have a "significant impact" upon another, and that impact in turn could render any appellate review on the other claim meaningless and a waste of judicial resources, the two claims are inextricably intertwined). The matters are REMANDED for the following action: Obtain an opinion from a qualified clinician to clarify whether the Veteran has had any neurological abnormalities, other than radiculopathy, related to her service-connected back disability during the appeal period. If the selected clinician determines that an examination is necessary to respond to this request, such examination should be scheduled. After review of the claims file, and examination of the Veteran if deemed necessary, the clinician should identify any neurological abnormalities, other than radiculopathy, related to the Veteran's service-connected back disability found during the period on appeal. In this regard, the examiner should address (1) October 2006 and July 2014 VA treatment records reflecting that the Veteran's back pain makes her walk slowly, and therefore she is not always able to make it to the bathroom in time, (2) a January 2020 VA treatment record noting urge incontinence, and (3) the February 2021 VA examination noting a remote incident of loss of bladder control during a flare-up of the Veteran's service-connected back condition. For any neurological abnormality, other than radiculopathy, related to the Veteran's service-connected back disability found during the period on appeal, the clinician should describe the condition and how it is related to the Veteran's service-connected back disability. In addition, any appropriate disability benefits questionnaires should be completed. The examiner is advised that the Veteran is competent to report her symptoms and history, and such reports must be specifically acknowledged and considered in formulating any opinion. If the examiner rejects the Veteran's reports, he or she must provide a reason for doing so; however, the Veteran's history of symptoms capable of lay observation cannot be dismissed solely on the basis that they are not recorded in contemporaneous treatment records. All findings must be reported in detail and all opinions must be accompanied by a clear rationale. If any of the above issues cannot be resolved without resorting to speculation, then a detailed medical explanation as to why this is so must be provided. M. HYLAND Veterans Law Judge Board of Veterans' Appeals Attorney for the Board M. Elias, 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.