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 Internal Popliteal Nerve, Paralysis.
Weak calf control
Primary condition · VASRD 8527
Internal Popliteal Nerve, Paralysis
Nerve damage affecting movement and sensation in the lower leg.
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 Internal Popliteal Nerve, Paralysis — severity of Knee, Other Impairment of itself determines the percentage.
Example combined rating
20% Internal Popliteal Nerve, Paralysis + 20% Knee, Other Impairment of = 36%
The VA combines ratings with Table I of 38 CFR 4.25, not simple addition — 20% and 20% combine to 36%, not 40%. These figures are illustrative; your actual rating for each condition depends on your own evaluation.
Primary condition
Full Internal Popliteal Nerve, Paralysis guide
Secondary condition
Full Knee, Other Impairment of guide
See how Internal Popliteal Nerve, Paralysis 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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