Purpose: Intra-articular corticosteroid injections is a well established treatment for knee osteoarthritis (OA). However, only 60% of patients have a good short-term response and about 20% of patients have a satisfactory long-term response. Genetic variants may play a role in predicting response to corticosteroids. A genetic variant of the macrophage inflammatory factor (MIF) (a physiologic counter-regulator of glucocorticoids), has been associated with poor clinical response in various inflammatory diseases. No studies to date have evaluated the effect of this variant on steroid injections for knee OA. We set out to determine the impact of the – 173(C) variant of the MIF gene on clinical response to intra-articular injections for knee OA.

Method: 80 patients with Kellgren-Lawrence Grade 2–3 OA of the knee were prospectively followed for three months following a standard dose of steroid injection. All patients were genotyped for the – 173 variant of the MIF gene. WOMAC questionnaires for knee OA were done at baseline, one, four and twelve weeks to assess response to treatment.

Results: 21 patients (25%) carried the C allele of – 173 variant of the MIF gene. At 12 weeks, patients with the C variant had a statistically significant decrease in the pain dimension of the WOMAC compared to the G variant. Similar responses were not obtained at weeks one and four.

Conclusion: A specific polymorphism in the MIF gene appears to be associated with a poor response to intra-articular knee injections. Further validation is required with larger sample sizes to assess the impact of prospectively genotyping for this variant prior to knee injections.

Purpose: Intra-articular (IA) steroid injections have been widely used by orthopedic surgeons as symptomatic relief for severe hip OA, and with the addition of local anesthetic, they can be used to differentiate pain from the hip, knee and lumbar spine. This technique has come under some question as of late however due to inconsistencies in the literature. It has been reported that there is an association between infection post Total Hip Arthroplasty (THA) and prior IA steroid injections (Kaspar & de Beer, 2005). Additionally, the incidence of infections has been noted to particularly rise when the injections occur within six weeks of the operation (McIntosh et al, 2006). This study was used to analyze the risk of intra-articular steroid injections with respect to infection following THA.

Method: We retrospectively reviewed 96 hips of patients who underwent total hip arthroplasty between 2001 and 2007 by one surgeon. Matched cohorts of 48 hips were established: one group in which patients received an injection prior to THA and one in which patients did not. Statistical analysis was performed using SPSS V14. Exclusion criteria included previous ipsilateral fracture or surgery, malignancy and immunosuppression.

Results: There was no significant difference found between groups and there was no correlation found with regards to time of injection prior to surgery and infection. Within the injected group, two patients developed a UTI while one other had a pulmonary embolism. There were zero infections with regards to the hip, and there were no dislocations or revisions. The non-injected group included one patient who developed cholelethiasis, another patient with Norfolk virus and one patient with a superficial infection which was contributed to a dental procedure. There were no dislocations or revisions.

Conclusion: These findings suggest that the administration of intra-articular steroid prior to THA does not increase risk of infection, and therefore our study does not find such an injection to be a contra-indicator.