Extracorporeal Shock Wave Therapy Is Effective in the Treatment of Bone Marrow Edema of the Medial Compartment of the Knee: A Comparative Study

OBJECTIVE: To test the hypothesis that shock wave therapy can produce a statistically significant improvement in symptoms and imaging features of the knee bone marrow edema syndrome (BMES) within 6 months of treatment. SUBJECTS AND METHODS: Eighty-six consecutive patients suffering from BMES of the medial compartment of the knee were prescribed a course of high-energy extracorporeal shock wave therapy (ESWT) and clinically followed up at 3 and 6 months and finally from 14 to approximately 18 months after treatment. Thirty-one patients were unable to undergo ESWT but returned for the 6-month and final follow-up; these were referred to as the conservative (control) group, while the other 55 patients constituted the ESWT group. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analog Scale (VAS) score of each patient were calculated at every follow-up. The BME area was assessed using magnetic resonance imaging before treatment and at the 6-month follow-up. RESULTS: Statistically significant improvements were observed in clinical scores and in the BME area for both the ESWT and the control group (p < 0.05). The improvements in the ESWT group were statistically better in all parameters compared with the control group: the ESWT group had a reduction in the BME area of 86% versus 41% in the control group, the VAS pain score improved by 88% in the ESWT group versus 42% in the control group, and the WOMAC score improved by 65% in the ESWT group versus 22% in the control group. Clinical scores were significantly better for patients with medial tibial lesions in the ESWT group. CONCLUSION: In this study, ESWT reduced pain and the BME area in the knee, with significant clinical improvement noticed 3 months after treatment.