The Joint Line Myth: Rethinking a Core Rule of Revision Knee Surgery

New data proves that a moderate joint line elevation in revision TKA doesn't sacrifice patient outcomes.

Despite the clinical success of primary total knee arthroplasty (TKA), complications requiring revision TKA (rTKA) persist. Treatment goals in rTKA are to perform a durable reconstruction that alleviates a patient’s pain and improves function. In rTKA, joint line elevation may occur when bone lost from the distal femur is not replaced, leading to historical recommendations that distal femoral augments be used to restore a native joint line.

The consequences of an elevated joint line were postulated to be inferior patient outcomes, decreased range of motion, less extensor strength, and anterior knee pain. However, interestingly, many “symptoms” of an elevated joint line can also be explained by instability, which has recently been described as one of the leading reasons for additional revisions of rTKAs. This study’s purpose was to evaluate the effect of joint line height elevation on validated patient-reported outcome measures (PROMs) using modern revision implants.