Investigators of this study found a difference in medial collateral ligament tension in their comparison of mobile-bearing and fixed-bearing unicompartmental knee arthroplasty, which they hypothesize may caused differences in the femoral-tibial correction angle.
Researchers compared 21 patients (24 knees) who underwent fixed-bearing unicompartmental knee arthroplasty (UKA) with 25 patients (28 knees) who underwent mobile-bearing UKA. Groups were compared for Knee Society score, range of joint motion and complications. Radiographs were obtained 3 weeks postoperatively. Investigators also compared groups for medial collateral ligament (MCL) tension, femoral-tibial angle (FTA) and postoperative correction angle.
Results showed a significantly larger mean difference between the preoperative and postoperative FTA for the mobile-bearing group compared with the fixed-bearing group. The mobile-bearing UKA group compared with the fixed-bearing UKA group also had a larger correction angle.
“In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation,” investigators wrote, noting this difference may have led to the different correction angles seen for the procedures. ‒ by Monica Jaramillo
Disclosures: The researchers report no relevant financial disclosures.