Effect of Different Size of Patellar Resurfacing on Patellar Crepitus of the One-stage Bilateral Total Knee Arthroplasty: a Prospective Randomize Control Trial.

For decades, total knee arthroplasty (TKA) has been the treatment of choice for knee osteoarthritis, with posterior-stabilized (PS) systems showing excellent long-term outcomes. However, patellar crepitus is more common with PS TKA systems because the cam and post mechanism can entrap fibrosynovial tissue within the intercondylar box, causing crepitus or clunking. Patellar crepitus (PC) was defined as an audible grinding noise or palpable vibrations in the knee during active and passive range of motion, detected by the examiner's hand on the patient's patella and sometimes can be audible.

This study was designed as a single-center, prospective randomized controlled trial comparing anatomical and reduced size of patella component in patients who underwent sequential bilateral TKA with patella resurfacing under single anesthesia. All participants were blinded to their intervention. A total of 94 knees from 47 patients were randomly assigned to undergo TKA with an anatomically sized patella component in one knee and reduced-size patella component in another knee or vice versa.

Crepitus, as a primary outcome, was assessed at 2, 6, 24 and 48 weeks follow-up using a validated and standardized approach. Crepitus was graded as: 0 (none), 1 (fine palpable), 2 (coarse palpable), and 3 (audible). Secondary outcomes included anterior knee pain (AKP), Feller's patella score (FPS), Kujala score, knee society score (KSS), range of motion (ROM), radiographic findings, and complications. AKP was measured using a 10-cm visual analog scale (VAS) in 1-cm increments. Knee ROM was measured with a goniometer. Radiographic parameters were measured at 6 months postoperatively.