The Impact of Pre-Operative Quadriceps Strength on Postoperative Rehabilitation: Subvastus versus Medial Parapatellar Approach

Background: Quadriceps weakness is an important determinant of functional recovery following total knee arthroplasty (TKA). Surgical approach and preoperative muscle strength may influence early postoperative rehabilitation. The objective is to compare postoperative rehabilitation between subvastus and medial parapatellar approaches and evaluate the relationship between preoperative quadriceps strength and postoperative functional recovery. Material and Methods: This prospective comparative study included 140 patients undergoing primary TKA, with 70 patients each in the subvastus and medial parapatellar groups. Quadriceps strength, pain, knee range of motion, straight-leg raising, independent ambulation, and functional outcomes were assessed during follow-up. Results: The subvastus group demonstrated significantly greater quadriceps strength at postoperative day 3 and two weeks, lower early pain scores, earlier straight-leg raising, and faster independent ambulation (p<0.05). Differences in strength and functional outcomes between groups diminished by three months. Preoperative quadriceps strength correlated significantly with postoperative strength at three months (r=0.74, p<0.001), functional score (r=0.48, p<0.001), and earlier rehabilitation milestones. Conclusion: The subvastus approach provided superior early rehabilitation following TKA, although long-term differences between approaches were limited. Higher preoperative quadriceps strength was associated with better postoperative functional recovery.

Keywords: Total knee arthroplasty; quadriceps strength; subvastus approach; medial parapatellar approach; rehabilitation; functional outcome.