Intraoperative changes in medial joint gap after posterior femoral condylar resection, posterior osteophyte removal, and femoral component placement during primary total knee arthroplasty

Background: Mid-flexion stability is important for superior patient satisfaction following total knee arthroplasty (TKA). Thus, it is important to control medial joint gap intraopera-tively as a countermeasure. However, reports on the precise intraoperative changes in medial joint gap during TKA are scarce. This study evaluated the intraoperative changes in medial joint gap during TKA. Methods: We studied 167 knees with varus osteoarthritis that underwent 80 cruciate-retaining (CR) and 87 posterior-stabilized (PS) TKAs between January 2018 and December 2020. We measured the intraoperative changes in medial joint gap with a tensor device at 137.5 N. Results: The medial joint gap after posterior femoral condylar resection was significantly increased not only at 90 degrees of flexion but also at 0 degrees of extension in CR and PS TKAs (p < 0.01). The medial joint gap after posterior osteophyte removal was significantly increased not only at 0 degrees of extension but also at 90 degrees of flexion in CR and PS TKAs (p < 0.01). The medial joint gap at 0 degrees of extension was reduced by 0.60 mm after femoral component placement in PS TKA. Conclusion: Surgeons need to pay close attention to these intraoperative changes in medial joint gap by measuring the medial joint gap before and after each procedure or assuming the changes in those values before bone cutting to achieve superior patient satisfaction fol-lowing TKA. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study evaluated the intraoperative changes in medial joint gap during total knee arthroplasty (TKA). The results showed that the medial joint gap significantly increased after posterior femoral condylar resection and posterior osteophyte removal. Surgeons need to measure the medial joint gap before and after each procedure or assume the changes in those values to achieve superior patient satisfaction following TKA.