EXTRACORPOREAL SHOCKWAVE TREATMENT OF EARLY SPONTANEOUS OSTEONECROSIS OF THE KNEE

Abstract

PURPOSE OF THE STUDY: We reported of eleven cases of early spontaneous osteonecrosis (SO) of the knee successfully treated with an extracorporeal shock-wave treatment (ESWT).

Traumatic and vascular theories have been proposed as the cause of the SO, lack of blood in some critical areas, such as subchondral bone of femoral condyles or tibial plateaus, has been considered the underlying condition of this pathology.

ESWT can be suggested as an effective conservative treatment for SO of the knee.

MATERIALS AND METHODS: Ten patients with medial femoral condyle osteonecrosis of the knee (one bilateral) were evaluated. Exclusion criteria was evidence of a structural collapse of subchondral bone. Two patients had received a femoro-popliteal by-pass within the last year, while others five presented a deficit of the vascular axis of the homolateral lower limb documented by an eco-colordoppler. A clinical evaluation was taken at the diagnosis using KSS, PPI, NRS and VAS. Plain radiographs and MRI confirmed the diagnosis of osteonecrosis.

Patients were treated with a cycle of three ESWT performed with 2000 pulses of 0,28 mJ/mm2 with Wolf Piezoson 300 with 6,5 MHz ultrasounds for three times in a month.

Clinical evaluation was performed at first and at third month after treatment and a MRI evaluation was performed at fourth month after treatment.

RESULTS: Clinical evaluation showed a significant improvement of symptoms and articular functionality. MRI of all cases revealed the continuity of the cartilage with a reduction in bone marrow edema and no collapse of lesion.

DISCUSSION: In our study, a single cycle of ESWT produced an improvement of the clinical and MRI aspects in eleven cases of SO of the knee. The neo-angiogenetic effect of the ESWT appears to accelerate the time for the symptom remission.

ESWT might have the potential to avoid the need for surgical treatment.