Secondary Condition Claim · VASRD 5257
A condition caused or aggravated by an already service-connected disability can be granted its own service connection as a secondary condition under 38 CFR § 3.310. Here's how that works for Knee, Other Impairment of when it develops after Loss of Use of One Foot.
Compensatory walking can cause joint strain
Primary condition · VASRD 5167
Loss of Use of One Foot
This code applies when a foot is still physically present but no longer functions well enough for effective walking or balance, essentially treating the functional loss the same as if the foot had been amputated. It's a strict, single-tier standard - the foot has to be functionally unusable, not just painful or weak.
Secondary condition · VASRD 5257
Knee, Other Impairment of
This diagnostic code covers knee instability — the knee buckling, giving out, or shifting out of place — separately from pain or arthritis. Since the 2021 rewrite it rates two named things: recurrent subluxation or instability after a ligament sprain or tear, and instability of the kneecap (the patellofemoral complex) after surgical repair. The tier you land on depends less on how bad the instability feels than on what a medical provider has prescribed for it — a brace, a walking aid, both, or neither.
The VA rates Knee, Other Impairment of the same way whether it's claimed directly or as secondary to Loss of Use of One Foot — severity of Knee, Other Impairment of itself determines the percentage.
| Rating | Criteria |
|---|---|
| 30% | The knee is unstable after a complete ligament tear that was not repaired or whose repair failed, and a provider has prescribed both a brace and a walking aid — or the kneecap is still unstable after surgery and needs both a brace and a cane or walker. |
| 20% | The knee is persistently unstable and a provider has prescribed a brace or a walking aid — one or the other, depending on whether the ligament tear was complete and whether it was repaired. |
| 10% | The knee is persistently unstable, but no provider has prescribed a brace or a walking aid for it. |
Example combined rating
40% Loss of Use of One Foot + 20% Knee, Other Impairment of = 52%
The VA combines ratings with Table I of 38 CFR 4.25, not simple addition — 40% and 20% combine to 52%, not 60%. These figures are illustrative; your actual rating for each condition depends on your own evaluation.
Get the rating criteria for Knee, Other Impairment of, the evidence a secondary claim needs, and why it is linked to Loss of Use of One Foot — delivered to your inbox.
Primary condition
Full Loss of Use of One Foot guide
Secondary condition
Full Knee, Other Impairment of guide
See how Loss of Use of One Foot and Knee, Other Impairment of combine with the rest of your service-connected conditions using the official VA combined-ratings formula.
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