Lateral release rates after total knee arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Proper patellar tracking is essential for optimal function after total knee replacement (TKR).
• Lateral release is a surgical technique sometimes employed to correct patellar maltracking.
• The Genesis II prosthesis with a deep-dish tibial insert was utilized in this study.

Purpose of the Study:

• To evaluate the accuracy of patellar tracking assessment techniques during TKR surgery.
• To determine the necessity and rate of lateral release procedures.
• To compare the effectiveness of the nontouch and modified no-touch techniques for evaluating patellar tracking.

Main Methods:

• 178 patients undergoing TKR with the Genesis II prosthesis were assessed for patellar tracking.
• The nontouch and axial traction (modified no-touch) techniques were used to evaluate patellar tilt and subluxation.
• Assessments were performed with the tourniquet inflated and deflated, and after lateral release if indicated.

Main Results:

• The modified no-touch technique identified fewer cases of lateral patellar tilt and subluxation compared to the nontouch technique before tourniquet deflation.
• The overall lateral release rate was 6%, primarily in patients with preoperative fixed valgus deformity.
• Radiographic evaluation showed no significant difference in patellar position between knees that underwent lateral release and those that did not.

Conclusions:

• The modified no-touch technique is more accurate in assessing patellar tracking, reducing the rate of unnecessary lateral releases.
• Axial realignment and implant design can effectively centralize the patella, often obviating the need for lateral release.
• Improved patellar tracking and reduced malalignment were observed postoperatively, with significant improvement by 3 months as quadriceps function returned.