Outcome of total hip replacement for avascular necrosis in systemic lupus erythematosus

Objective. To describe the short and medium term results of total hip arthroplasty (THA) for avascular necrosis in patients with systemic lupus erythematosus (SLE). Methods. Nineteen patients with SLE and avascular necrosis of the femoral head (AVNFH), who underwent 26 THA were retrospectively reviewed with a minimum followup of 2 years. To determine whether these patients had results similar to those of patients with other conditions, we formed a control group of 19 patients who had 29 THA. They were matched for age, sex, and followup to the patients with SLE. Controls had THA for juvenile rheumatoid arthritis (n = 7), osteoarthritis (5), adult onset rheumatoid arthritis (8), developmental dysplasia of the hip (4), and other diagnoses (5). Outcome measures included a 10 point visual analog scale (VAS) for pain, the Harris hip score, and the SF-36 self-administered health outcome questionnaire. We used the methods of Delee, Harris, and Engh for radiological assessment. Results, Mean age at surgery was 46 years (range 21-71 years) and average followup was 4 years, 7 months (range 1 yr 9 mo to 9 yrs 6 mo), similar in both groups. Technical problems, mostly consisting of small, nonpropagating cracks of the calcar in uncemented stems, were encountered in 4 SLE hips and 1 control hip. Six complications were noted in the SLE group, including 2 early, nonrecurrent dislocations, 1 patient with thigh pain for 1 year, 1 pericarditis, 1 sick-sinus syndrome, and 1 urinary tract infection. There was one case of urinary tract infection in the control group. One SLE patient developed a low grade prosthetic infection and underwent successful revision 2 years after primary surgery. Clinical outcome measures had similar scores in the 2 groups: average VAS pain score = 2.00 in SLE hips (maximum 10) and 1.97 in control hips; mean Harris hip score = 86.7 in SLE patients (maximum 100) and 81.9 in controls; average SF-36 score = 63.4 in SLE patients (maximum 100) and 60.5 in controls. There was no radiological evidence of implant loosening in controls; there was 1 asymptomatic cup migration in the SLE group. Conclusion. In the short and medium term, patients with SLE and AVN had good results after THA. Results were similar in patients who had hip replacement for other diagnoses. Less favorable clinical outcomes of hip replacement have been reported in young patients who have AVN of other etiology (e.g., alcoholic, post-traumatic), but this was not the case in our young patients who had AVN and SLE. Thus, AVNFH and SLE should not constitute a contraindication to hip replacement.