Effectiveness of Muscle Energy Technique in Fixed Flexion Deformity after Post ACL Surgery a Single Case Study

Background: Anterior Cruciate Ligament (ACL) injury and reconstruction are common in active individuals. Postoperative complications such as fixed flexion deformity (FFD) often occur due to arthrofibrosis, posterior capsule tightness, or quadriceps inhibition. Loss of full knee extension negatively impacts gait, increases energy expenditure, and predisposes to early osteoarthritis. Objective: To assess the effectiveness of Muscle Energy Technique in improving hamstring flexibility and reducing knee flexion contracture after ACL surgery. To evaluate the role of VMO strengthening in restoring knee extension and quadriceps control. To measure improvement in extension range, pain reduction, and function outcome following the combined 6-week intervention. Methodology: This study was done on people aged 18–40 years who had ACL surgery and developed a fixed flexion deformity (FFD) between 5°–15°, about 4–8 weeks after surgery. Those with meniscus repair limits, re-injury, infection, or nerve problems were not included. The treatment lasted six weeks and used Muscle Energy Technique (MET) for the hamstrings and VMO strengthening exercises. Patients also received cryotherapy, stretching, and patellar mobilization as supportive therapy. Improvement was checked using a goniometer for knee movement, VAS for pain, and MMT for muscle strength. Results: After six weeks of treatment, the patients showed clear improvement in their knee movement and overall function. The ability to straighten the knee increased by about 8° to 12°, showing better knee extension. Pain levels reduced from about 9 out of 10 before treatment to around 1 or 2 out of 10 after treatment. The strength of the quadriceps muscles also improved by at least one grade on the manual muscle test, showing better control and activation Conclusion: The six-week program using Muscle Energy Technique (MET) and VMO strengthening was effective in improving knee extension, reducing pain, and increasing quadriceps strength in patients with fixed flexion deformity after ACL reconstruction. MET helped release hamstring tightness, while VMO exercises improved knee control and stability. Early use of these techniques can prevent long-term extension problems and promote better functional recovery after surgery.