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 Thigh, Limitation of Extension.
Poor movement can affect surrounding joints
Primary condition · VASRD 5251
Thigh, Limitation of Extension
This diagnostic code covers limited hip and thigh extension - difficulty moving the leg backward from the hip - which is a distinct, specific measurement separate from general hip or thigh pain. Because there's only a single 10% rating tier for this code, the entire claim depends on documenting that the extension loss meets the specific threshold.
Secondary condition · VASRD 5257
Knee, Other Impairment of
This diagnostic code covers knee instability - the knee buckling, giving out, or feeling loose during activity - separate from simple pain or arthritis. It's rated on how often and how severely the knee subluxates (partially dislocates) or shifts out of place, which is a different rating track than knee pain alone.
The VA rates Knee, Other Impairment of the same way whether it's claimed directly or as secondary to Thigh, Limitation of Extension — severity of Knee, Other Impairment of itself determines the percentage.
Example combined rating
10% Thigh, Limitation of Extension + 20% Knee, Other Impairment of = 28%
The VA combines ratings with Table I of 38 CFR 4.25, not simple addition — 10% and 20% combine to 28%, not 30%. These figures are illustrative; your actual rating for each condition depends on your own evaluation.
Primary condition
Full Thigh, Limitation of Extension guide
Secondary condition
Full Knee, Other Impairment of guide
See how Thigh, Limitation of Extension 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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