Citation Nr: 21005755 Decision Date: 02/02/21 Archive Date: 02/02/21 DOCKET NO. 18-19 038 DATE: February 2, 2021 ORDER Entitlement to service connection for a right knee disability is denied. Entitlement to a rating in excess of 10 percent for degenerative arthritis of the left knee is denied. Entitlement to a separate 10 percent rating, but not higher, for a left knee disability, based on slight lateral instability of the knee pursuant to Diagnostic Code 5257, effective June 12, 2015, but not earlier, is granted. Entitlement to a rating in excess of 10 percent for degenerative arthritis of the lumbar spine is denied. Entitlement to a total disability rating based on individual unemployability due to service-connected disability (TDIU), as of June 18, 2019, is denied. REMANDED Entitlement to TDIU prior to June 18, 2019, is remanded. FINDINGS OF FACT 1. In October 2020, the Veteran, without good cause, cancelled a scheduled VA examination that was necessary to evaluate the claim of entitlement to service connection for a right knee disability. 2. A right knee disability has not been shown to be etiologically related to any incident or injury incurred during active service or to be caused or aggravated by any service-connected disability 3. A left knee disability was manifested by pain and discomfort; it has not been manifested by flexion limited to 45 degrees or less for an objectively sustained period, extension limited to 15 degrees or greater for an objectively sustained period, ankylosis, objective evidence of recurrent subluxation, lateral instability, impairment of the tibia and fibula, genu recurvatum, or effusion. 4. Effective June 12, 2015, the evidence of record shows slight left knee lateral instability 5. Throughout the period of appeal, the evidence did not show limitation of thoracolumbar spine greater than 30 degrees but not greater than 60 degrees; or a combined range of motion of the thoracolumbar spine not greater than 120 degrees; or, muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour such as scoliosis, reversed lordosis, or abnormal kyphosis 6. The issue of entitlement to TDIU is moot as of June 18, 2019. CONCLUSIONS OF LAW 1. The criteria for entitlement to a rating in excess of 10 percent for degenerative arthritis of the left knee have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.159, 4.1, 4.2, 4.3, 4.7, 4.71a, Diagnostic Codes 5003, 5256-5263. 2. Resolving reasonable doubt in favor of the Veteran, the criteria for a separate 10 percent rating, but not higher, for slight left knee instability, effective June 12, 2015, but not earlier, have been met.   38 U.S.C. § 1155; 38 C.F.R. § 4.71a, Diagnostic Code 5257. 3. The criteria for entitlement to a rating in excess of 10 percent for degenerative arthritis of the lumbar spine have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.321, 4.1, 4.2, 4.3, 4.7, 4.71a, Diagnostic Code 5235- 5243 4. The criteria for service connection for a right knee disability have not been met. 38 U.S.C. §§ 1110, 1131, 1137, 5103A, 5107; 38 C.F.R. § 3.655. 5. The issue of entitlement to a TDIU for the period as of June 18, 2019, is made moot by the assignment of a 100 percent rating for bilateral hearing loss as of June 18, 2019. 38 U.S.C. §§ 7104, 7105(d)(5). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from August 1953 to August 1956 and from August 1957 to August 1974. This matter comes to the Board of Veterans’ Appeals (Board) on appeal from October 2015, March 2016, and October 2018 rating decisions by the Department of Veterans Affairs (VA) Regional Office (RO). In February 2020, the Board remanded these claims to the Agency of Original Jurisdiction for additional action. This appeal has been advanced on the Board’s docket pursuant to 38 C.F.R. § 20.900(c); 38 U.S.C. § 7107(a)(2). Increased Rating 1. Entitlement to a rating in excess of 10 percent for degenerative arthritis of the left knee. Disability ratings are based on VA’s Schedule for Rating Disabilities.  38 C.F.R. Part 4.  Separate Diagnostic Codes identify various disabilities and the criteria for a specific percentage rating to be assigned for that disability.  The percentage ratings represent as far as practicably can be determined the average impairment in earning capacity due to a service-connected disability.  38 U.S.C. § 1155.  A rating is assigned by comparing the extent to which a service-connected disability impairs the ability to function under the ordinary conditions of daily life, as demonstrated by the symptomatology, with criteria established for the percentage ratings.  38 U.S.C. § 1155; 38 C.F.R. § 4.10; Schafrath v. Derwinski, 1 Vet. App. 589 (1991).  Disabilities must be reviewed in relation to their history.  38 C.F.R. § 4.1. Examination reports must be interpreted, and if necessary reconciled, into a consistent picture so that the rating may accurately compensate the elements of disability present.  38 C.F.R. § 4.2.  If two ratings are potentially applicable, the higher rating 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.  The Board must determine the probative weight to be assigned among evidence in a case, and to state reasons or bases for favoring one opinion over another.  If all the evidence is in relative equipoise, reasonable doubt shall be resolved in the Veteran’s favor, and the claim should be granted.  38 U.S.C. § 5107; 38 C.F.R. § 3.102.  If the preponderance of the evidence is against the claim, the claim must be denied.  Gilbert v. Derwinski, 1 Vet. App. 49 (1990).  Rating a service-connected disability involving a joint rated on limitation of motion requires adequate consideration of functional loss due to pain and functional loss due to weakness, fatigability, incoordination, or pain on movement of a joint.  38 C.F.R. § 4.45; DeLuca v. Brown, 8 Vet. App. 202 (1995).  Disability of the musculoskeletal system is primarily the inability, due to damage or infection in parts of the system, to perform the normal working movements of the body with normal excursion, strength, speed, coordination, and endurance.  It is essential that the examination on which ratings are based adequately portrays the anatomical damage, and the functional loss, with respect to these elements.  In addition, the regulations state that the functional loss may be due to pain, supported by adequate pathology and evidenced by the visible behavior of the veteran undertaking the motion.  Weakness is as important as limitation of motion, and a part which becomes painful on use must be regarded as seriously disabled.  38 C.F.R. § 4.40.  When rating the joints, inquiry will be directed as to whether there is less movement than normal, more movement than normal, weakened movement, excess fatigability, incoordination, and pain on movement.  38 C.F.R. § 4.45.  The intent of the schedule is to recognize painful motion with joint or periarticular pathology as productive of disability.  It is the intention to recognize actually painful, unstable, or malaligned joints, due to healed injury, as entitled to at least the minimum compensable rating for the joint.  38 C.F.R. § 4.59.  The rating of the same disability under different diagnostic codes, known as pyramiding, must be avoided.  However, separate ratings may be assigned for distinct disabilities resulting from the same injury so long as the symptomatology for one condition is not duplicative of the symptomatology of the other condition.  38 C.F.R. § 4.14; Esteban v. Brown, 6 Vet. App. 259 (1994).  Normal range of motion of the knee is to 0 degrees extension and to 140 degrees flexion.  38 C.F.R. § 4.71a, Plate II.  Under Diagnostic Code 5256, a 40 percent rating is warranted for ankylosis of the knee in flexion between 10 degrees and 20 degrees.  A 50 percent rating is warranted for ankylosis in flexion between 20 degrees and 45 degrees.  A 60 percent rating is warranted for extremity unfavorable ankylosis in flexion at an angle of 45 degrees or more.  38 C.F.R. § 4.71a, Diagnostic Code 5256.  Diagnostic Code 5257 provides that a 10 percent rating is warranted for slight recurrent subluxation or lateral instability of a knee.  A 20 percent rating is warranted for moderate recurrent subluxation or lateral instability.  A 30 percent rating is warranted for severe knee impairment with recurrent subluxation or lateral instability.  38 C.F.R. § 4.71a, Diagnostic Code 5257.  Subluxation of the patella is the incomplete or partial dislocation of the knee cap.  Rykhus v. Brown, 6 Vet. App. 354 (1993).  Under Diagnostic Code 5260, limitation of flexion of the knee is rated 10 percent for flexion limited to 45 degrees.  A 20 percent rating is assigned for flexion limited to 30 degrees.  A 30 percent rating is assigned for flexion limited to 15 degrees.  38 C.F.R. § 4.71a, Diagnostic Code 5260.  Under Diagnostic Code 5261, limitation of extension of the knee is rated 10 percent for extension limited to 10 degrees.  A 20 percent rating is assigned for extension limited to 15 degrees.  A 30 percent rating is assigned for extension limited to 20 degrees.  A 40 percent rating is assigned for extension limited to 30 degrees.  A 50 percent rating is assigned for extension limited to 45 degrees. 38 C.F.R. § 4.71a, Diagnostic Code 5261.  Pursuant to Diagnostic Code 5262, a 30 percent rating is warranted when there is malunion of the tibia and fibula, with marked knee or ankle disability.  A schedular maximum 40 percent rating is warranted when there is nonunion of the tibia and fibula, with loose motion requiring a brace.  38 C.F.R. § 4.71a, Diagnostic Code 5262.  The words slight, moderate, and severe as used in the various Diagnostic Codes are not defined in the VA Schedule for Rating Disabilities. Rather than applying a mechanical formula, the Board must evaluate all of the evidence, to the end that decisions are equitable and just.  38 C.F.R. § 4.6.  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).  Diagnostic Code 5003 provides that degenerative arthritis established by X-ray findings will be rated on the basis of limitation of motion under the appropriate diagnostic codes for the specific joint or joints involved.  38 C.F.R. § 4.71a.  When limitation of motion of the specific joint or joints involved is noncompensable under the appropriate diagnostic codes, a rating of 10 percent is generally for application.  Limitation of motion must be objectively confirmed by findings such as swelling, muscle spasm, or satisfactory evidence of painful motion.  A rating for arthritis cannot be combined with a rating based on limitation of motion of the same joint.  38 C.F.R. § 4.71a, Diagnostic Code 5003.  The Veteran is currently assigned a 10 percent rating for degenerative arthritis of the left knee effective October 7, 2014, pursuant to Diagnostic Code 5003- 5261. This claim for an increased rating was received by VA in June 2015. The Veteran asserts that the left knee disability is more severe than that represented by the assigned ratings. As an initial matter, the Board notes that the Veteran underwent VA knee examination in September 2015 and October 2018. However, the Board finds the September 2015 and October 2018 knee examinations to be incomplete as the examiners did not provide opinions as to functional loss of range of motion during flare-ups or after repeated use over time and did not adequately explain why that information was not provided. The Board notes that an opinion is speculative when it is based on the absence of procurable information or an examiner’s shortcomings or general aversion to offering an opinion on issues not directly observed. Direct observation of functional impairment during a flare-up or after repeated use over time is not a prerequisite to offering an opinion. The applicable case law and VA regulations and guidelines anticipate that examiners will offer flare up opinions based on estimates derived from information procured from relevant sources, including the lay statements of Veterans.  Sharp v. Shulkin, 29 Vet. App. 26 (2017).  Therefore, as to limitation of motion, the Board finds that those examinations are not indicative because of procedural inadequacies. Accordingly, the Board finds the September 2015 and October 2018 VA knee examination reports to be incomplete for rating purposes and neither examination will be considered in adjudication of this claim. In a June 2015 orthopedic surgery consult, the Veteran complained of bilateral knee pain. The Veteran was diagnosed with moderate to severe osteoarthritis. The Veteran’s left knee was noted as having full range of motion, no effusion, pain on patella compression, and pain along the medial and lateral joint line. No ligamentous dysfunction was noted. A March 2017 primary care note described the Veteran as experiencing muscle cramps, joint pain, and stiffness. The Veteran was noted as experiencing weakness when walking. In a July 2017 orthopedic surgery note, the Veteran complained of bilateral knee pain. The Veteran was diagnosed with degenerative joint disease. The left knee was negative for effusion and ligamentous dysfunction. The Veteran was able to ambulate with a cane and had good quad tone. In a November 2017 orthopedic surgery note, the Veteran complained of intermittent left knee pain and increased pain with prolonged weight bearing. The Veteran was able to ambulate using a cane but favored the left knee. The Veteran’s left knee had full active range of motion, and was negative for effusion and ligamentous dysfunction. The Veteran had mild pain along the medial and lateral joint line. In October 2018 the Veteran was issued a brace for the left knee. The Veteran was scheduled for VA knee examination pursuant to a February 2020 Board remand. However, in October 2020, the Veteran cancelled the examination and did not provide any good cause for not attending that examination. On review of the record, there is no indication, either by the Veteran or the representative, that an attempt has been made to reschedule or otherwise provide good cause for attending the VA examination. The Board finds no evidence of any VA error in notifying or assisting the Veteran. While VA has a statutory duty to assist in developing evidence pertinent to a claim, a Veteran also has a duty to assist and cooperate with VA in developing evidence. The duty to assist is not a one-way street. Wood v. Derwinski, 1 Vet. App. 190 (1991). VA’s duty must be understood as a duty to assist a Veteran in developing his or her claim, rather than a duty on the part of VA to develop the entire claim with the Veteran performing a passive role. Turk v. Peake, 21 Vet. App. 565 (2008). Therefore, remand for an additional VA examination is not warranted. Disability ratings are determined by applying the criteria set forth in VA’s Schedule for Rating Disabilities. The record currently contains no VA examinations contemporaneous with the appeal period that are valid for rating purposes.  For the period on appeal, the Board finds that the preponderance of the evidence is against the assignment of a compensable rating under Diagnostic Code 5260 for limitation of flexion of the left knee.  Concerning the left knee, the evidence does not show limitation of flexion to 45 degrees at any time during this appeal, or that any pain or other functionally limiting factors limited flexion to 45 degrees. Therefore, an increased rating for limitation of flexion is not warranted as the contemporaneous evidence of record does not warrant a compensable rating. The Board further finds that the preponderance of the evidence is against the assignment of any higher rating under Diagnostic Code 5261 for limitation of extension of the left knee. Concerning the left knee, the evidence does not show that Veteran’s left knee disability has been manifested by limitation of extension to 15 degrees or worse commensurate with a 20 percent rating. Therefore, a higher rating for limitation of extension is not warranted as the contemporaneous evidence of record does not warrant an increased disability rating. Throughout the entire appeal period, the Board finds that Diagnostic Codes 5256 (ankylosis of the knee), 5258 (dislocated semilunar cartilage), 5259 (symptomatic removal of semilunar cartilage), 5263 (genu recurvatum), and 5262 (nonunion or malunion of the tibia and fibula) are not applicable, as the medical evidence does not show that the Veteran has those conditions in the left knee. Accordingly, the Board finds that the preponderance of the evidence is against the assignment of any higher or additional separate ratings for the left knee disability based on limitation of motion and the claim for increased rating must be denied. Gilbert v. Derwinski, 1 Vet. App. 49 (1990); 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 2. Entitlement to a separate 10 percent rating, but not higher, for a left knee disability, based on slight lateral instability of the knee pursuant to Diagnostic Code 5257, effective June 12, 2015. The Board finds that a separate 10 percent rating under Diagnostic Code 5257 for slight recurrent knee lateral instability is warranted for the left knee disability, effective June 12, 2015, the date the Veteran first filed the claim for increased rating, as there is lay and medical evidence that the left knee occasionally gave way.  As early as a September 2015 ambulatory/outpatient care note, the Veteran reported the legs giving out. The Board will resolve reasonable doubt in favor of the Veteran and find that slight recurrent lateral instability is shown to warrant a 10 percent rating under Diagnostic Code 5257.  The evidence does not show more than occasional giving way or any symptoms that would lead the Board to conclude that any recurrent lateral instability has been any more than slight.  The Board finds that the preponderance of the evidence is against a finding of more than slight instability as objective signs or indicators of instability have not been found on examination, that would warrant a finding of more than slight recurrent lateral instability. In addition, the Veteran did not attend an examination scheduled to determine the current severity of the left knee disability. The Board finds that the preponderance of the evidence is against the assignment of any rating higher than 10 percent or any earlier effective date for the separate rating. 3. Entitlement to a rating in excess of 10 percent for degenerative arthritis of the lumbar spine. Disabilities of the spine that are rated under the General Rating Formula for Diseases and Injuries of the Spine include vertebral fracture or dislocation (Diagnostic Code 5235), sacroiliac injury and weakness (Diagnostic Code 5236), lumbosacral or cervical strain (Diagnostic Code 5237), spinal stenosis (Diagnostic Code 5238), unfavorable or segmental instability (Diagnostic Code 5239), ankylosing spondylitis (Diagnostic Code 5240), spinal fusion (Diagnostic Code 5241), and degenerative arthritis of the spine (Diagnostic Code 5242). Degenerative arthritis of the spine can also be rated using Diagnostic Code 5003. 38 C.F.R. § 4.71a. The General Rating Formula for Diseases and Injuries of the Spine provides a 20 percent rating for forward flexion of the thoracolumbar spine greater than 30 degrees but not greater than 60 degrees; or, a combined range of motion of the thoracolumbar spine not greater than 120 degrees; or, muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour such as scoliosis, reversed lordosis, or abnormal kyphosis. 38 C.F.R. § 4.71a. A 30 percent rating is assigned for forward flexion of the cervical spine 15 degrees or less; or, favorable ankylosis of the entire cervical spine. 38 C.F.R. § 4.71a. A 40 percent rating is assigned for forward flexion of the thoracolumbar spine of 30 degrees or less; or, favorable ankylosis of the entire thoracolumbar spine. A 50 percent rating is assigned for unfavorable ankylosis of the entire thoracolumbar spine. A 100 percent rating is assigned for unfavorable ankylosis of entire spine. 38 C.F.R. § 4.71a. Any associated objective neurologic abnormalities, including, but not limited to, bowel or bladder impairment, should be rated separately under an appropriate Diagnostic Code. 38 C.F.R. § 4.71a, General Rating Formula for Diseases and Injuries of the Spine, Note (1). For VA compensation purposes, normal forward flexion of the thoracolumbar spine is 0 to 90 degrees, extension is 0 to 30 degrees, left and right lateral flexion are 0 to 30 degrees, and left and right lateral rotation are 0 to 30 degrees. The combined range of motion refers to the sum of the range of forward flexion, extension, left and right lateral flexion, and left and right rotation. The normal ranges of motion for each component of spinal motion provided in this note are the maximum that can be used for calculation of the combined range of motion. 38 C.F.R. § 4.71a , Plate V, General Rating Formula for Diseases and Injuries of the Spine, Note (2). The rater is to round each range of motion measurement to the nearest five degrees. 38 C.F.R. § 4.71a, General Rating Formula for Diseases and Injuries of the Spine, Note (4). In exceptional cases, an examiner may state that because of age, body habitus, neurologic disease, or other factors not the result of disease or injury of the spine, the range of motion of the spine in a particular individual should be considered normal for that individual, even though it does not conform to the normal range of motion. Provided that the examiner supplies an explanation, the examiner’s assessment that the range of motion is normal for that individual will be accepted. 38 C.F.R. § 4.71a, General Rating Formula for Diseases and Injuries of the Spine, Note (3). Unfavorable ankylosis is a condition in which the entire cervical spine, the entire thoracolumbar spine, or the entire spine is fixed in flexion or extension, and the ankylosis results in one or more of the following: difficulty walking because of a limited line of vision; restricted opening of the mouth and chewing; breathing limited to diaphragmatic respiration; gastrointestinal symptoms due to pressure of the costal margin on the abdomen; dyspnea or dysphagia; atlantoaxial or cervical subluxation or dislocation; or neurologic symptoms due to nerve root stretching. Fixation of a spinal segment in neutral position (0 degrees) always represents favorable ankylosis. The rater is to round each range of motion measurement to the nearest five degrees. 38 C.F.R. § 4.71a, General Rating Formula for Diseases and Injuries of the Spine, Note (5). Disability of the thoracolumbar and cervical spine segments are to be rated separately, except when there is unfavorable ankylosis of both segments, which will be rated as a single disability. The rater is to round each range of motion measurement to the nearest five degrees. 38 C.F.R. § 4.71a, General Rating Formula for Diseases and Injuries of the Spine, Note (6). Diagnostic Code 5243 provides that intervertebral disc syndrome (IVDS) is to be rated either under the General Rating Formula for Diseases and Injuries of the Spine or under the Formula for Rating Intervertebral Disc Syndrome Based on Incapacitating Episodes, whichever method results in the higher rating when all disabilities are combined under 38 C.F.R. § 4.25. The Formula for Rating Intervertebral Disc Syndrome (IVDS) Based on Incapacitating Episodes provides that a 10 percent rating is warranted for IVDS with incapacitating episodes having a total duration of at least one week but less than two weeks during the past 12 months. A 20 percent rating is warranted for IVDS with incapacitating episodes having a total duration of at least two weeks but less than four weeks during the past 12 months. A 40 percent rating is warranted for IVDS with incapacitating episodes having a total duration of at least four weeks but less than six weeks during the past 12 months. A 60 percent rating is warranted for IVDS with incapacitating episodes having a total duration of at least six weeks during the past 12 months. 38 C.F.R. § 4.71a, Diagnostic Code 5243, Formula for Rating Intervertebral Disc Syndrome Based on Incapacitating Episodes. An incapacitating episode is a period of acute signs and symptoms due to intervertebral disc syndrome that requires bed rest prescribed by a physician and treatment by a physician. 38 C.F.R. § 4.71a, Diagnostic Code 5243, Formula for Rating Intervertebral Disc Syndrome Based on Incapacitating Episodes, Note (1). If intervertebral disc syndrome is present in more than one spinal segment, provided that the effects in each segment are clearly distinct, each segment is to be rated on the basis of incapacitating episodes or under the General Rating Formula for Diseases and Injuries of the Spine, whichever method results in a higher rating for that segment. 38 C.F.R. § 4.71a, Diagnostic Code 5243, Formula for Rating Intervertebral Disc Syndrome Based on Incapacitating Episodes, Note (2). The claim for an increased rating was received by VA on June 12, 2015. The Veteran’s degenerative arthritis of the lumbar spine has been rated under Diagnostic Codes 5242 as 10 percent disabling, effective October 7, 2014. As an initial matter, the Board notes that the Veteran underwent VA back examination in September 2015. The Board finds the September 2015 back examination to be incomplete as the examiner did not provide an opinion as to functional loss of range of motion during flare-ups or after repeated use over time because the Veteran was not examiner during a flare-up or after repeated use. The Board notes that an opinion is speculative when it is based on the absence of procurable information or an examiner’s shortcomings or general aversion to offering an opinion on issues not directly observed. Direct observation of functional impairment during a flare-up is not a prerequisite to offering an opinion. Case law and VA guidelines anticipate that examiners will offer flare up opinions based on estimates derived from information procured from relevant sources, including the lay statements of Veterans.  Sharp v. Shulkin, 29 Vet. App. 26 (2017).  Therefore, the Board finds that the range of motion measured at that examination are no considered adequate to use for rating. Accordingly, the Board finds the September 2015 VA back examination report to be incomplete for rating purposes and it will not be considered in adjudication of this claim. The Board further notes that a February 2020 Board decision found the Veteran’s October 2018 VA back examination to be incomplete for rating purposes and it will also not be considered in adjudication of this claim. In a July 2018 orthopedic surgery note, an X-Ray found L3-S1 bilateral pedicular screws and rods, with interbody fusion at L3-L4 and L4-L5. There were laminectomies at L3 and L4. There were surgical clips in the right upper abdomen. There was disc narrowing, spondylosis and first degree retrolisthesis at L2-L3. There was also vacuum phenomenon at L2-L3. There was calcification in the aorta and the iliacs. There was disc narrowing and spondylosis at T11-T12. The remainder of the pedicles and lamina were intact. The Veteran was noted as having reduced range of motion in all five planes, tight paraspinal muscle, and reduced reflexes. In a November 2018 orthotics prosthetics consult, the Veteran complained of balance issues and lumbar spine back pain that radiated down his bilateral lower extremities. The Veteran was diagnosed with stenosis of the lumbar spine. The Veteran was scheduled for VA back examination pursuant to the February 2020 Board remand. However, in October 2020, the Veteran cancelled the examination and did not provide any good cause for not attending that examination. On review of the record, there is no indication, either by the Veteran or the representative, that an attempt has been made to reschedule or otherwise provide good cause for failure to appear for the VA examination. Further, the Board finds no evidence of any VA error in notifying or assisting the Veteran. While VA has a statutory duty to assist in developing evidence pertinent to a claim, a Veteran also has a duty to assist and cooperate with VA in developing evidence. The duty to assist is not a one-way street. Wood v. Derwinski, 1 Vet. App. 190 (1991). VA’s duty must be understood as a duty to assist a Veteran in developing his or her claim, rather than a duty on the part of VA to develop the entire claim with the Veteran performing a passive role. Turk v. Peake, 21 Vet. App. 565 (2008). Therefore, remand for an additional VA examination is not warranted. Disability ratings are determined by applying the criteria set forth in VA’s Schedule for Rating Disabilities. The record currently contains no VA examinations contemporaneous to the appeal period that are valid for rating purposes.  The Board notes that there has been no medical evidence of ankylosis of the entire thoracolumbar spine during the course of the appeal. While there was interbody fusion at L3-L4 and L4-L5, that does not represent ankylosis of the entire thoracolumbar spine. Thus, a higher rating cannot be assigned on that basis. Throughout the appeal period, the Board finds that the evidence did not show limitation of lumbar spine flexion to be greater than 30 degrees but not greater than 60 degrees. The evidence also did not show a combined range of motion of the thoracolumbar spine not greater than 120 degrees; or, muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour such as scoliosis, reversed lordosis, or abnormal kyphosis. Therefore, a rating higher than 10 percent is not warranted. The Board has considered any additional limitation of function due to pain and other factors, but the evidence does not show any additional limitation of function that would support the assignment of a rating greater than 10 percent. The evidence also does not show muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour such as scoliosis, reversed lordosis, or abnormal kyphosis. The Board has also considered whether a higher rating could be assigned under the intervertebral disc syndrome formula based on incapacitating episodes. However, to date, the Veteran has not been shown to have incapacitating episodes of intervertebral disc syndrome requiring bed rest prescribed by a physician and treatment by a physician of any duration. Accordingly, the Board finds that the preponderance of the evidence is against the assignment of a rating greater than 10 percent for a lumbar spine disability. Therefore, the Board finds that the preponderance of the evidence is against the assignment of any higher ratings and the appeal must be and is denied. Gilbert v. Derwinski, 1 Vet. App. 49 (1990); 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 4. Service connection for a right knee disability. Service connection may be established for disability caused by disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. §§ 3.303, 3.304. In order to establish service connection for a claimed disability, there must be (1) medical evidence of a current disability; (2) medical, or in certain circumstances, lay evidence of in-service incurrence or aggravation of a disease or injury; and (3) evidence, generally medical, of a causal relationship between the claimed in service disease or injury and the current disability. Hickson v. West, 12 Vet. App. 247 (1999). Service connection may also be established for any disease initially diagnosed after service, when the evidence establishes that the disease was incurred in-service. 38 U.S.C. § 1113(b); 38 C.F.R. § 3.303(d); Cosman v. Principi, 3 Vet. App. 503 (1992). The disease entity for which service connection is sought must be chronic rather than acute and transitory in nature. For the showing of chronic disease in service, a combination of manifestations must exist sufficient to identify the disease entity and sufficient observation to establish chronicity at the time, as distinguished from merely isolated findings or a diagnosis including the word chronic. Secondary service connection may be established for a disability that is proximately due to, or aggravated by, a service-connected disease or injury. 38 C.F.R. § 3.310. Competent lay evidence means any evidence not requiring that the proponent have specialized education, training, or experience. Lay evidence is competent if it is provided by a person who has knowledge of the facts or circumstances and conveys matters that can be observed and described by a lay person. 38 C.F.R. § 3.159(a)(2). Lay testimony is competent when it regards the readily observable features or symptoms of injury or illness and may provide sufficient support for a claim of service connection. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). The Veteran is competent to provide testimony concerning factual matters of which he has firsthand knowledge, such as experiencing a physical symptom such as pain. Barr v. Nicholson, 21 Vet. App. 303 (2007); Washington v. Nicholson, 19 Vet. App. 362 (2005). Therefore, the Board must assess the competence and credibility of lay statements. Barr v. Nicholson, 21 Vet. App. 303 (2007). Competency of evidence differs from weight and credibility. Competency is a legal concept determining whether testimony may be heard and considered by the trier of fact, while weight and credibility are factual determinations going to the probative value of the evidence to be made after the evidence has been admitted. Rucker v. Brown, 10 Vet. App. 67 (1997). A Veteran need only demonstrate that there is an approximate balance of positive and negative evidence to prevail. To deny a claim on its merits, the preponderance of the evidence must be against the claim. Alemany v. Brown, 9 Vet. App. 518 (1996); Gilbert v. Derwinski, 1 Vet. App. 49 (1990). While the Board must provide reasons and bases supporting a decision, there is no need to discuss, in detail, the evidence submitted by or on behalf of the Veteran. Gonzales v. West, 218 F.3d 1378 (Fed. Cir. 2000) (Board must review the entire record, but does not have to discuss each piece of evidence). The analysis below focuses on the most salient and relevant evidence of record. The Veteran should not assume that the Board has overlooked pieces of evidence that are not explicitly discussed. Timberlake v. Gober, 14 Vet. App. 122 (2000). The Veteran contends that he is entitled to service connection for a right knee disability. Specifically, the Veteran asserts that a current right knee disability is secondary to service-connected left knee disabilities. The service medical records do not show treatment for, complaints of, or a diagnosed right knee disability while in-service. Post-service treatment records show the Veteran consistently complaining of right knee pain and undergoing a right total knee replacement in 2016. As an initial matter, the Board notes that the Veteran underwent VA knee examination in September 2015. That examination did not provide an opinion as to whether any right knee disability was related to service or was caused or aggravated by a service-connected disability, to include the left knee disability. In support of the claim, the Veteran has provided a medical statement dated April 11, 2017. In that statement, an examiner states that the Veteran’s right knee problems are directly related to back and opposite knee problems. The Board finds the April 2017 private opinion to be incomplete, as the examiner did not provide an adequate rationale to support the opinion. A mere conclusion without an underlying rationale is of no probative value. Miller v. West, 11 Vet. App. 345 (1998). The Board finds the April 2017 private opinion to be inadequate as the examiner did not properly explain what led to the opinion and cited no supporting evidence. The examiner simply stated that a right knee disability was related to back and left knee disabilities but provided no reasoning for that opinion. As the April 2017 examiner did not provide an adequate rationale, the opinion is incomplete.  Therefore, the April 2017 private does not establish that it is at least as likely as not that any right knee disability was incurred in service or was caused or aggravated by service-connected disability. In a February 2020 Remand, the Board requested an examination and medical opinion regarding the etiology of the claimed right knee disability. The Veteran was scheduled for a VA examination pursuant to the February 2020 Board remand. However, in October 2020, the Veteran cancelled the scheduled examination and did not provide any good cause for not attending the examination. On review of the record, there is no indication, either by the Veteran or the representative, that an attempt has been made to reschedule or otherwise provide good cause for failure to appear for the VA examination. The Board finds no evidence of any VA error in notifying or assisting the Veteran. While VA has a statutory duty to assist in developing evidence pertinent to a claim, a Veteran also has a duty to assist and cooperate with VA in developing evidence. The duty to assist is not a one-way street. Wood v. Derwinski, 1 Vet. App. 190 (1991). VA’s duty must be understood as a duty to assist a Veteran in developing his or her claim, rather than a duty on the part of VA to develop the entire claim with the Veteran performing a passive role. Turk v. Peake, 21 Vet. App. 565 (2008). Therefore, remand for an additional VA examination is not warranted. When entitlement cannot be established or confirmed without a current VA examination or reexamination and a claimant, without good cause, fails to report for a scheduled examination, or reexamination, the claim shall be denied. 38 C.F.R. § 3.655. The Board recognizes that the Veteran has asserted a current disability is secondary to a service-connected disability. However, the Board finds that, the Veteran, as a layman without the appropriate medical training and expertise, is not competent to provide a probative opinion as to whether a right knee disability was either caused or aggravated beyond its normal progression by any incident of active service, or by another service-connected disability. Madden v. Gober, 125 F.3d 1477 (Fed. Cir. 1997). The Veteran has not been shown to possess the adequate medical knowledge, education, or training, to competently opine as to the diagnosis or etiology of any disability. In addition, the Veteran has not provided any probative medical statement, from a competent medical provider, relating the claimed disability to service or a service-connected disability. The Board remanded this claim for further consideration and development, to include providing the Veteran with a VA examination to diagnose and determine the etiology of any right knee disability. The Board specifically requested that, had the Veteran appeared and participated at the scheduled examination, the examiner was to opine whether the claimed disability had its onset during service or was related to service or a service-connected disability. However, the Veteran was provided with notice of the examination and did not attend. Consequently, adjudication on the merits of the existing record is proper. Therefore, as no probative, competent, medical evidence has been presented to show any relationship between the Veteran’s service and the claimed right knee disability, service connection must be denied. As the Veteran, without good cause, did not attend a scheduled VA examination, and as entitlement to service connection for a right knee disability cannot be established without a VA examination, the Board will adjudicate on the basis of the evidence of record. The Board finds that the preponderance of the evidence is against a finding that any right knee disability is related to service; any event, injury, or disease during service; or was caused or aggravated by a service-connected disability. Accordingly, the claim of service connection for a right knee disability must be denied. 38 C.F.R. § 3.655. 5. The claim for TDIU is moot as of June 18, 2019. A claim for TDIU is considered part of an increased rating claim when the issue of unemployability is raised by the record. Rice v. Shinseki, 22 Vet. App. 447 (2009). The Veteran asserts unemployability due to service-connected disabilities during the current appeal. However, the claim of entitlement to TDIU, effective June 18, 2019, has been made moot by the award of a 100 percent schedular rating for bilateral hearing loss, effective June 18, 2019. Bradley v. Peake, 22 Vet. App. 280 (2008). A 100 percent rating under the Schedule for Rating Disabilities means that a Veteran is totally disabled. Holland v. Brown, 6 Vet. App. 443 (1994); Swan v. Derwinski, 1 Vet. App. 20 (1990). Thus, if VA has found a Veteran to be totally disabled as a result of a particular service-connected disability, there is no need, and no authority, to otherwise rate that Veteran totally disabled on any other basis. Herlehy v. Principi, 15 Vet. App. 33 (2001) (request for TDIU moot where 100 percent schedular rating was awarded for the same period). As the Veteran is now in receipt of a 100 percent rating, effective June 18, 2019, based on the service-connected bilateral hearing loss disability, effective June 18, 2019, there remains no time where the schedular rating is less than total, as required for consideration of the assignment of TDIU. 38 C.F.R. § 4.16. The Board is cognizant of the fact that the receipt of a 100 percent schedular rating for a service-connected disability or disabilities does not necessarily moot the issue of entitlement to a TDIU because a TDIU rating may still form the basis for assignment of special monthly compensation (SMC) pursuant to 38 U.S.C. § 1114(s). Bradley v. Peake, 22 Vet. App. 280 (2008). VA's duty to maximize a claimant's benefits includes consideration of whether disabilities establish entitlement to SMC under 38 U.S.C. § 1114. Buie v. Shinseki, 24 Vet. App. 242 (2011). Specifically, SMC may be warranted if the Veteran has a 100 percent disability rating for a single disability, and VA finds that TDIU is warranted based solely on the disabilities other than the disability that is rated at 100 percent. Bradley v. Peake, 22 Vet. App. 280 (2008). That scenario is not present here, as the Veteran is assigned a 100 percent rating for a hearing loss disability and prior to June 18, 2018, the Veteran's disability ratings did not meet the percentage requirements for consideration for TDIU pursuant to 38 C.F.R. § 4.16(a). The Board further notes that the Veteran is already in receipt of SMC for service-connected bilateral hearing loss effective June 18, 2019. Therefore, the issue of entitlement to a TDIU is moot as of June 18, 2019. The assignment of a 100 percent rating for service-connected bilateral hearing loss effective June 18, 2019, makes the issue of entitlement to TDIU moot as of that date. Accordingly, the Board finds that the issue of entitlement to TDIU is moot and the claim for TDIU as of June 18, 2019, is denied. Bradley v. Peake, 22 Vet. App. 280 (2008); Buie v. Shinseki, 24 Vet. App. 242 (2010). REASONS FOR REMAND Entitlement to TDIU prior to June 18, 2019, is remanded. Remand is required regarding the claim for TDIU prior to June 18, 2019, as the Board finds that this issue should be referred to the Director of Compensation and Pension Services for consideration of the assignment of TDIU pursuant to 38 C.F.R. § 4.16(b). For consideration for TDIU pursuant to 38 C.F.R. § 4.16(a), the Veteran must meet a minimum percentage combined service-connected rating. If the Veteran has one service-connected disability, it must be rated 60 percent or more. If the Veteran has two or more service-connected disabilities, at least one disability must be rated 40 percent or more and the combined rating of all the service-connected disabilities must be 70 percent or more. 38 C.F.R. § 4.16(a). Where a Veteran does not meet the percentage rating requirements under 38 C.F.R. § 4.16(a), the Veteran still may be found totally disabled pursuant to 38 C.F.R. § 4.16(b) when the evidence indicates that the Veteran is unemployable by reason of service-connected disabilities. During the period prior to June 18, 2019, the Veteran's service-connected disabilities were assigned a 50 percent combined rating, with no single disability in excess of 30 percent. Under that circumstance, the matter is referred to the Director for consideration. Bagwell v. Brown, 9 Vet. App. 337 (1996); Floyd v. Brown, 9 Vet. App. 88 (1996); Shipwash v. Brown, 8 Vet. App. 218 (1995). TDIU consideration requires contemplation of the severity of the Veteran's service-connected disabilities, employment history, educational and vocational attainment, and all other factors having a bearing on the issue. 38 C.F.R. § 4.16(b). Although the Board does not have the authority to award TDIU under 38 C.F.R. § 4.16(b) prior to referral to the Director, the Board has jurisdiction to review and award extraschedular ratings in claims that have been denied by the Director. Kuppamala v. McDonald, 27 Vet. App. 447 (2015). In determining whether TDIU is warranted, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the Veteran prevailing in either event, or whether a preponderance of the evidence is against the claim, in which case the claim is denied. 38 U.S.C. § 5107; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination, reasonable doubt is resolved in favor of the claimant. The Veteran is already in receipt of a 100 percent schedular rating effective June 18, 2019. Prior to June 18, 2019, it is unclear, at best, whether the Veteran was unable to secure or follow substantially gainful employment due to the service-connected disabilities. In a February 2020 Remand, the Board requested the Veteran file a formal application for TDIU and furnish any additional information or evidence pertinent to the claim. After several requests, the Veteran has not completed and returned a VA Form 21-8940 to provide an employment history and employment information. The exact date the Veteran was last employed is currently unclear based of the record. The Board further notes that the Veteran was scheduled for VA examination pursuant to the February 2020 Board remand. As part of that examination, the examiner was to opine as to whether it was at least as likely as not (50 percent or greater probability) that the Veteran was unable to secure or follow a substantially gainful occupation due to the combined effects of the service-connected disabilities, without consideration of age or nonservice-connected disabilities. However, in October 2020, the Veteran cancelled the scheduled examination and did not provide any good cause for not attending the examination. On review of the record, there is no indication, either by the Veteran or the representative, that an attempt has been made to reschedule or otherwise provide good cause for failure to appear for the VA examination. The Board finds no evidence of any VA error in notifying or assisting the Veteran. While VA has a statutory duty to assist in developing evidence pertinent to a claim, a Veteran also has a duty to assist and cooperate with VA in developing evidence. The duty to assist is not a one-way street. Wood v. Derwinski, 1 Vet. App. 190 (1991). VA’s duty must be understood as a duty to assist a Veteran in developing a claim, rather than a duty on the part of VA to develop the entire claim with the Veteran performing a passive role. Turk v. Peake, 21 Vet. App. 565 (2008). Therefore, remand for an additional VA examination is not warranted. The Veteran has been provided numerous VA examinations for the service-connected disabilities, to include of hearing loss, left knee, back, jaw, and hernia disabilities. The salient, and most relevant part of these examination reports noted functional loss that impact the Veteran's inability to hear; or stand, bend, squat, push, pull, lift, sit, or walk for prolonged periods of time. In support of the claim, the Veteran has also provided a March 2018 private medical opinion. In that opinion, a physician opined that the Veteran was unemployed due to the service-connected disabilities, but did not provide any rationale for the opinion. Therefore, in viewing the Veteran's disability picture in its totality, and evaluating the Veteran's work history and education, the Board notes that there is sufficient evidence to suggest that the Veteran's service-connected disabilities, prior to June 18, 2019, may have created a circumstance in which the Veteran could possibly not have obtained or maintained substantially gainful employment and that referral to the Director for consideration of the assignment of TDIU pursuant to 38 C.F.R. § 4.16(b) is warranted. The matters are REMANDED for the following action: Refer the issue of entitlement to TDIU prior to June 18, 2019, pursuant to 38 C.F.R. § 4.16(b)to the Director of the Compensation Service for consideration. Send the Director the entire claims file. If the Director finds that the Veteran is not entitled to TDIU pursuant to 38 C.F.R. § 4.16(b) prior to June 18, 2019, the Director should issue a memorandum explaining the reasons for that decision and a summary of the evidence considered. Harvey P. Roberts Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board Mondesir, Eric 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.