Home › Conditions › Secondary claims › Back Pain ← a Knee Injury
A secondary claim is a condition caused or worsened by one the VA has already service-connected (38 CFR 3.310). The causation fight is already half-won — the VA agreed your a knee injury came from service; the question is only whether it caused or aggravated the back pain. That's a medical question with a recognized answer.
The connection
Favoring a bad knee for years is not free — the limp shifts load to the opposite leg, the hips, and the spine. Compensation-gait injury is a well-recognized secondary theory, and it works in every direction along the kinetic chain: knee to back, knee to opposite knee, hip to spine.
How the VA rates back pain
General Rating Formula for Diseases and Injuries of the Spine (DC 5235–5243)
| Rating | Criteria (38 CFR Part 4 wording) |
|---|---|
| 100% | Unfavorable ankylosis of the entire spine |
| 50% | Unfavorable ankylosis of the entire thoracolumbar spine |
| 40% | Unfavorable ankylosis of the entire cervical spine; or forward flexion of the thoracolumbar spine 30 degrees or less; or favorable ankylosis of the entire thoracolumbar spine |
| 30% | Forward flexion of the cervical spine 15 degrees or less; or favorable ankylosis of the entire cervical spine |
| 20% | Forward flexion of the thoracolumbar spine greater than 30 degrees but not greater than 60 degrees; or forward flexion of the cervical spine greater than 15 degrees but not greater than 30 degrees; or combined range of motion of the thoracolumbar spine not greater than 120 degrees; or combined range of motion of the cervical spine not greater than 170 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 |
| 10% | Forward flexion of the thoracolumbar spine greater than 60 degrees but not greater than 85 degrees; or forward flexion of the cervical spine greater than 30 degrees but not greater than 40 degrees; or combined range of motion of the thoracolumbar spine greater than 120 degrees but not greater than 235 degrees; or combined range of motion of the cervical spine greater than 170 degrees but not greater than 335 degrees; or muscle spasm, guarding, or localized tenderness not resulting in abnormal gait or abnormal spinal contour; or vertebral body fracture with loss of 50 percent or more of the height |
Applies with or without symptoms such as pain (whether or not it radiates), stiffness, or aching in the area of the spine affected.
Note (1): Evaluate any associated objective neurologic abnormalities, including bowel or bladder impairment, separately under an appropriate diagnostic code — this is where radiculopathy (DC 8520 and others) is rated on top of the spine rating.
Note (2): Normal forward flexion of the thoracolumbar spine is 0 to 90 degrees (combined ROM 240); normal forward flexion of the cervical spine is 0 to 45 degrees (combined ROM 340).
Note (4): Round each range of motion measurement to the nearest five degrees.
Note (6): The thoracolumbar and cervical segments are rated separately.
Full criteria, exam and evidence guide: VA rating for Back and Neck Conditions. And the anchor: VA rating for Knee, Hip and Shoulder Conditions.
What the claim needs — the three legs
- The anchor: service connection for the a knee injury (see how that condition is rated). Not connected yet? File both in the same claim — the VA decides the anchor first, then the secondary against it.
- A current diagnosis of back pain — the VA rates diagnosed conditions. If you only have the symptoms, file them anyway: the C&P exam supplies the diagnosis, and a "no diagnosis" denial is repaired with a supplemental claim that keeps your date.
- The medical link. An opinion stating it is "at least as likely as not" that the a knee injury caused or aggravated the back pain. The VA's own C&P examiner supplies this free in most cases; your own doctor can too. A paid independent opinion is the answer to a denial, not the first move.
Think you're underrated? Find out in 2 minutes.
Flat fee. You keep 100% of your back pay. Money-back guarantee — in writing, before you pay a dollar.
See If You Qualify →Frequently asked questions
Can I claim back pain secondary to a knee injury?
Yes, if three things hold: the a knee injury (or its equivalent) is service-connected, you have a current diagnosis of back pain, and a medical opinion connects the two. The connection described on this page is a recognized pathway raters see regularly.
Do I need to pay for a nexus letter for back pain secondary to a knee injury?
Usually not. The VA's own C&P examiner can supply the connecting opinion at your exam for free, and your own treating doctor can also provide it. A paid independent opinion is worth buying only after a denial for lack of nexus — a supplemental claim within one year keeps the original effective date.
What if the primary condition isn't service-connected yet?
File them together in the same claim. The VA decides the primary first and then the secondary against it in the same decision; a secondary filed alone against a condition the VA has not connected fails. Filing both at once under one Intent to File protects the effective date for both.
Last reviewed 2026-09-19.