The use of extracorporeal shock wave therapy (ESWT) in treating osteonecrosis of the femoral head (AVNFH): a retrospective study.

Abstract

As most of the cases of avascular necrosis (AVN) in Saudi Arabia is seen in young population and as literature showed good effect of extracorporeal shock wave therapy (ESWT) in reducing pain and oedema in avascular necrosis and delaying the need of surgical intervention. Our purpose of this study is to assess the effectiveness of ESWT in reducing pain, improving range of motion (ROM) and delaying the surgical intervention in patient with AVN of femoral head and compare our results to published literature. We have treated 24 patients, 13 males and 11 females with a mean age of 29 years (range 14-48) with 34 hips affected. There were 14 unilateral and ten bilateral lesions. In our series 11 out of 24 patients (45.8%) were due to sickle cell disease. Other causes included idiopathic in five patients (20.8%), corticosteroids use and systemic lupus erythematous in three patients each (12.5% each) and post-traumatic AVN in two patients (8.3%). Extracorporeal shock wave therapy was implanted in FICAT stage I, II and III. All patients had two sessions of extracorporeal shock wave therapy, four to six weeks apart, each with 4000 impulses divided into four points. Radiological and MRI assessment were performed at regular time intervals with a minimum follow-up of two years. Clinical assessment was based on Visual Analog Scale and Harris Hip Score (HHS). The end point outcome measurement was the need for any operative intervention. Operative intervention was necessary in eight out of 34 hips (23.5%), within an average of 2.5 years (range 1 to 5 years). A hip salvage was achieved in 76.5%. Function was improved with the Harris Hip Score from a mean of 54.6 to 80.4 (P value using paired t test ≤ 0.05). Pain assessed with Visual Analog Scale improved from 5.73 to 2.75 (P value using paired t test ≤ 0.05). We do recommend the use of ESWT in treating AVN of bone whether of femoral head or other sites prior to the collapse of the articular surface. Further studies are needed to compare using two or more sessions as well as using four or six points for ESWT.