Clinical and Radiological Outcomes of Extracorporeal Shock Wave Therapy in Early-Stage Femoral Head Osteonecrosis.

Objective: Femoral head osteonecrosis is a progressive clinical condition with significant morbidity and long-term disability. Several treatment modalities including both surgical and nonsurgical options have been used with variable levels of success. High-energy extracorporeal shock wave therapy is a nonoperative treatment option that has been described for early-stage disease. We aimed to assess the functional and radiological outcomes of extracorporeal shockwave therapy (ESWT) in the treatment of osteonecrosis of the femoral head (ONFH).

Methods: Thirty-three hips of 21 patients were included in this study. Adult patients with ONFH of any etiology and in the precollapse stage were included. Clinical (visual analogue scale [VAS] and Harris hip score [HHS]) and radiological (plain radiographs and magnetic resonance imaging [MRI]) evaluations were performed before and after intervention. We used 3000-4500 pulses in a single session performed under general anesthesia.

Results: At an average of 8 months after ESWT, pain scores and HHS were significantly improved compared with the preintervention scores (p<0.001). The overall clinical outcomes were improved in 21 hips (63.3%), unchanged in 5 hips (15.15%), and worsened in 7 hips (21.2%). A trend toward a decrease in the size of the ONFH was observed although not of clinical significance (p=0.235). MRI revealed significant resolution of bone marrow edema (p<0.003). Regression was observed in 9 lesions (42.9%) and progression in 1 lesion (4.7%); no change was observed in the remaining 23 lesions (52.4%).

Conclusion: ESWT is a viable noninvasive treatment option for early-stage ONFH. It significantly improves clinical outcomes and may halt or delay the radiographic progression of the disease in the precollapse stage.