Bone Marrow Edema Syndrome of the Medial Femoral Condyle Treated With Extracorporeal Shock Wave Therapy: A Clinical and MRI Retrospective Comparative Study.

OBJECTIVE: To determine the validity of extracorporeal shock wave therapy (ESWT) in the treatment of bone marrow edema (BME) of the medial condyle of the knee.

DESIGN: Retrospective.

SETTING: Orthopedic Surgery outpatient clinic.

PARTICIPANTS: Symptomatic patients (N=56) affected by BME of the medial condyle of the knee. Patients were equally divided into an ESWT-treated group and a control group, which was managed conservatively.

INTERVENTIONS: ESWT delivery to the medial condyle of the affected knee.

MAIN OUTCOME MEASURES: Clinical and functional assessment of the knee was performed with the use of the clinical and functional scores of the Knee Society Score (KSS). Pain was measured with the visual analog scale (VAS). BME area was measured with magnetic resonance imaging (MRI) before treatment and at 4 months' follow-up.

RESULTS: Clinical evaluation of patients at final follow-up of 4 months posttreatment showed a significant improvement (P<.0001) of symptoms and knee functionality, both for range of motion and strength in both groups. VAS values were significantly improved (P<.0001) in both groups, with 3 patients in the ESWT group being pain-free (VAS=0) at 4 months' follow-up. At 4 months, MRI assessments on both sagittal and coronal views showed a significant reduction in BME in the ESWT group compared with the control group.

CONCLUSIONS: Our findings show that ESWT is a valid nonpharmacologic and noninvasive therapy for spontaneous BME of the medial condyle that improves the affected vascular and metabolic state present in this pathologic disorder through its metabolic mechanisms of action.