A comparison between extracorporeal shockwave therapy and dextrose prolotherapy on quadriceps muscle performance in knee osteoarthritis

Introduction: The Quadriceps Femoris muscle group frequently exhibits weakness in individuals diagnosed with knee Osteoarthritis (OA). This weakness arises from muscle atrophy and mechanisms such as arthrogenic muscle inhibition. Emerging therapies such as hypertonic Dextrose Prolotherapy (DP) and Extracorporeal Shockwave Therapy (ESWT) offer promising intervention for knee OA, focusing on pain relief and functional improvement. This study aims to evaluate and compare the effects between ESWT and DP on pain, quadriceps femoris muscle thickness and the Vastus Medial Oblique (VMO) electromyography (EMG) activity in knee OA patients. Methods: Eighteen subjects with unilateral knee OA grade 2-3 (Kellgren-Lawrence) randomized into ESWT and DP group. The ESWT group received six sessions of focused-ESWT therapy, with 1-week interval. The dextrose prolotherapy (DP) group received three-injection regime with 3-weeks interval between injections. The VAS score, Quadriceps Femoris muscle thickness measured by musculoskeletal ultrasound, and VMO EMG activity recorded by surface EMG (sEMG) were measured before and after interventions. Results: There were significant improvement of VAS score in both DP group (p = 0.007) and ESWT group (p = 0.006). The Quadriceps Femoris muscle thickness showed no significant improvement in both groups (p > 0.05), while VMO sEMG activity showed improvement of VMOmax in ESWT group (p < 0.001), and VMOavg in both groups (p = 0.012 and p = 0.001). Conclusion: Both ESWT and DP improved pain and VMO EMG activity in knee OA patients, with comparable results between the two interventions. No significant changes of quadriceps femoris muscle thickness was found in both groups after interventions.