Introduction: Intra-articular steroid injection has been widely used for relief of pain in osteoarthritis. Recent studies show an increasing rate of infection in these patients following hip arthroplasty. We have reviewed our cohort of patients to see if they are susceptible to higher infection rate.

Methods: We reviewed a cohort of 167 consecutive hips that had at least one injection with a 40mg triamcinolone acetonide and 4ml 0.5% bupivacaine mixture to relieve the symptoms of hip osteoarthritis or to clarify a diagnosis of hip arthritis between January 1997 and November 2004 were reviewed. A total of 37 hips (36 patients) that subsequently proceeded to have a total hip arthroplasty were selected as our study group. There was a minimum of a one-year follow up.

Results: The rate of infection in our initial cohort of patients following a hip injection was 0.60% (1 hip) which resulted in repeated washouts and a subsequent total hip arthroplasty with a good outcome. On review of the 37 hips, one was revised due to a deep infection secondary to staphylococcus epidermidis. Four were revised for continued instability and pain with no evidence of infection either prior to or during revision. When deep infection is taken as an endpoint, cumulative survival at 7.5 years is 0.968 (95% confidence interval of 1 to 0.905). The total survivorship of this cohort if all revisions are included is 0.852 at 7.5 years (95% confidence interval of 0.730 to 0.974). The revision rate due to a deep infection in our study is 2.7%.

Discussion: We conclude that patients who have a total hip arthroplasty after a hip injection do not have an adversely high rate of deep infection.