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Published on: May 5, 2023
Changes in Joint Gap Balances between Intra- and Postoperation in Total Knee Arthroplasty
Arata Nakajima1, Yasuchika Aoki2, Masazumi Murakami3
1Department of Orthopaedic Surgery, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Chiba 285-8741, Japan ; Department of Orthopaedic Surgery, Chiba Aoba Municipal Hospital, 1273-2 Aoba-cho, Chuo-ku, Chiba 260-0852, Japan.
Total knee arthroplasty (TKA) gap balances shift post-surgery. Surgeons should avoid excessive medial soft tissue release in varus knees, as intraoperative findings may not predict postoperative total knee arthroplasty outcomes.
Area of Science:
- Orthopedic Surgery
- Biomechanical Engineering
Background:
- Achieving balanced joint gaps is critical for successful total knee arthroplasty (TKA).
- Postoperative changes in TKA joint gap balance are not fully understood.
- Varus knees present unique challenges in TKA soft tissue balancing.
Purpose of the Study:
- To investigate the changes in knee joint gap balance from intraoperative to postoperative states in posterior cruciate ligament-retaining TKA.
- To determine if intraoperative gap balance predicts postoperative outcomes in TKA for varus knees.
Main Methods:
- Prospective study of 21 patients undergoing posterior cruciate ligament-retaining TKA for varus knees.
- Measurement of intraoperative extension gap balance (iEGB) and intraoperative flexion gap balance (iFGB).
- Measurement of postoperative extension gap balance (pEGB) and postoperative flexion gap balance (pFGB).
Main Results:
- A significant shift from intraoperative varus (2.6°) to postoperative valgus (0.77°) extension gap balance was observed (P < 0.01).
- No significant difference was found between intraoperative and postoperative flexion gap balance.
- No significant correlation was found between intraoperative and postoperative gap balances.
Conclusions:
- Surgeons should exercise caution regarding excessive medial soft tissue release during TKA for varus knees.
- Intraoperative TKA gap balance measurements may not reliably predict postoperative joint gap balance.
