Total hip arthroplasty in ankylosing spondylitis: outcome in 340 patients.

OBJECTIVE

The longterm outcome of total hip arthroplasty (THA) in ankylosing spondylitis (AS) remains unclear. Concern has been expressed regarding joint survival, given that recipients are young and active. We present outcome data on 340 THA after a mean followup of 14 years.

METHODS

The 6.7% of patients (n = 309: 237 contactable) who had undergone THA were identified from our database of 4569 subjects. Responses were received from 166 subjects (112 men, 54 women, M:F = 2:1) who were assessed for employment status and outcome [i.e., pain, mobility, satisfaction, disease activity (BASDAI), function (BASFI), and global well being (BAS-G)]. A non-THA AS control group was matched for age, sex, and disease duration.

RESULTS

The mean age at AS disease onset for THA recipients was 19.5 yrs compared to 24.4 yrs for the total database (p < 0.05). The mean age at the first THA was 40.0 yrs. Of the 340 THA, 276 were primary (bilateral in 66%) and 64 were revisions. The mean followup for THA was 14.0 yrs (range 1-52). Overall, for the 340 THA, the patients considered outcome to be very good in 85%. In relation to the matched control group, THA patients were comparable for BASDAI, but had poorer function (p < 0.05) and lower global well being (p < 0.05). Of the 80 men under 60 years of age, 39 (49%) were employed compared to 49 (68%) of the control group (p < 0.01). Survival of original THA and revisions after 10, 15, and 20 yrs was 90%, 78%, 64%, respectively (originals), and 73%, 55%, 55%, respectively (revisions).

CONCLUSION

The longterm outcome of THA in AS is outstanding. THA recipients have a younger age at onset than nonrecipients. The longterm survival characteristics of THA in young patients with AS is excellent.