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

Objective. To describe the short and medium term results of total hip arthr oplasty (THA) for avascular necrosis in patients with systemic lupus erythe matosus (SLE). Methods. Nineteen patients with SLE and avascular necrosis of the femoral h ead (AVNFH), who underwent 26 THA were retrospectively reviewed with a mini mum followup of 2 years. To determine whether these patients had results si milar 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 followu p to the patients with SLE. Controls had THA for juvenile rheumatoid arthri tis (n = 7), osteoarthritis (5), adult onset rheumatoid arthritis (8), deve lopmental dysplasia of the hip (4), and other diagnoses (5). Outcome measur es included a 10 point visual analog scale (VAS) for pain, the Harris hip s core, 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 f ollowup was 4 years, 7 months (range 1 yr 9 mo to 9 yrs 6 mo), similar in b oth groups. Technical problems, mostly consisting of small, nonpropagating cracks of the calcar in uncemented stems, were encountered in 4 SLE hips an d 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 w as one case of urinary tract infection in the control group. One SLE patien t developed a low grade prosthetic infection and underwent successful revis ion 2 years after primary surgery. Clinical outcome measures had similar sc ores 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 (m aximum 100) and 81.9 in controls; average SF-36 score = 63.4 in SLE patient s (maximum 100) and 60.5 in controls. There was no radiological evidence of implant loosening in controls; there was 1 asymptomatic cup migration in t he SLE group. Conclusion. In the short and medium term, patients with SLE and AVN had goo d results after THA. Results were similar in patients who had hip replaceme nt 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 patient s who had AVN and SLE. Thus, AVNFH and SLE should not constitute a contrain dication to hip replacement.