Effect of Pes Anserinus Release on Postoperative Pain and Medial Stability in Medial Opening Wedge High Tibial Osteotomy

<i>Background and Objectives:</i> Medial opening wedge high tibial osteotomy (OWHTO) requires careful management of medial soft-tissue tension to achieve effective decompression and maintain knee stability. While superficial medial collateral ligament (sMCL) release is commonly performed, the role of pes anserinus release remains unclear. This study investigated the effect of pes anserinus release on postoperative pain, clinical outcomes, and medial stability in patients undergoing OWHTO. <i>Materials and Methods:</i> A retrospective analysis was performed on 80 knees (80 patients) that underwent OWHTO between 2012 and 2017. Patients were divided into two groups: Group A (n = 38, sMCL release only) and Group B (n = 42, sMCL + pes anserinus release). Immediate postoperative pain was assessed using visual analog scale (VAS) scores and rescue analgesic use. Clinical outcomes were evaluated with Knee Society Scores (KSSs). Radiographic medial joint opening (MJO) was measured on valgus stress radiographs preoperatively and at one year postoperatively. <i>Results</i>: Group B demonstrated significantly lower VAS pain scores at postoperative days (PODs) 1, 3, 5, 7, and 14 (<i>p</i> < 0.05) and required fewer rescue analgesics (5.5 ± 2.1 vs. 7.6 ± 3.7; <i>p</i> < 0.05). Both groups achieved comparable KSS improvement and radiographic correction (postoperative mechanical femorotibial angle: 2.1° valgus vs. 2.5° valgus). No significant intergroup or intragroup differences were observed in MJO at one-year follow-up (<i>p</i> > 0.05). <i>Conclusions</i>: Combined release of the superficial medial collateral ligament and pes anserinus during medial opening wedge high tibial osteotomy significantly reduces early postoperative pain and improves short-term functional recovery without compromising medial stability or alignment correction, although no significant long-term differences in functional outcomes or radiographic alignment were observed.