RESULTS OF UNCEMENTED TOTAL HIP REPLACEMENT IN JUVENILE IDIOPATHIC ARTHRITIS

Abstract

Introduction: The benefits of total hip replacement in patients with juvenile idiopathic arthritis are well documented. However only few results of uncemented total replacement with subsequent problems of loosening and revision surgery have been published. We report a minimum 2 year follow-up of uncemented total hip replacement in this group of patients

Material s& Methods: Between 1995 and 2003, 56 patients under the age of 29 years underwent 81 uncemented total hip replacements. 41 were females and 15 were males.1 patient died and 1 lost for follow -up. The average length of follow up was 6 years (range 2 to 10 yrs). In 67% of the patients the follow up period was 5 yrs or longer. The average age of onset of the disease was 5 yrs (range 1 to 19 yrs). The mean age at surgery was 18 yrs (range 11 to 29 yrs). Both hips were involved in 25 patients of which 18 were women and 7 were men. The mean interval between the onset of arthritis and surgery was 11 yrs. The mean interval between symptoms of hip involvement and hip replacement was 4.7 yrs. In 49% of patients the onset of arthritis was systemic, 22.6% polyarticular, 15.09% pauciarticular and 13.21% seronegative. Prior soft tissue release was performed in 6 hips(4).2 patients had previous supra-condylar femoral osteotomy for deformity correction.2 patients had total knee replacements(bilateral 1, unilateral 1). Usually a posterior approach was employed. A variety of prosthesis were used, Furlong HAC stem in 40 patients, SROM in 23 patients and CAD CAM in 17 patients. On the acetabular side, Furlong CSFHDP in 31 patients, Furlong ceramic in 15 patients, SROM cup in 21 patients, Duraloc cup in 9 patients and Muller support ring in 4 patients. The hips were graded before surgery and at follow-up using the scoring system of the Hospital for Special Surgery (Salvati and Wilson 1973)

Results: The mean improvement of HSS score for pain, ROM, mobility and function are 6.3, 3.1, 3.5 and 4.1 respectively. There was a mean improvement of 17.0 in the total HSS score. One patient had subsidence of both the CAD CAM stems at present waiting for revision. Radiolucent zones around the proximal sleeve SROM stem was noted in one patient requiring stem revision. Stress shielding of calcar was noted in 3 patients (CAD CAM 2, Furlong 1) and osteolysis around the cup in 1 patient. All patients with Furlong stem had very good osseointegration and there was no need of any revision. All patients with SROM stems also had very good osseointegration except one for which stem revision was done.

Conclusion: This study shows a lower revision rate and better radiographic appearance compared to previous reports with similar follow up of THA in Juvenile Idiopathic Arthritis.