In the JournalsFrom OT Europe

Larger correction angle found with mobile-bearing vs fixed-bearing UKA

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.

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.