Intra-articular bupivacaine hip injection in differentiation of coxarthrosis from referred thigh pain: a 10 year study.

The authors conducted a retrospective study to validate the specificity of intra-articular injection of local anaesthetic to identify the source of pain in patients with coxarthrosis but ill-defined clinical and radiological features. Forty-seven patients received intra-articular injection of the hip joint as a diagnostic procedure. Twenty-four patients showed a positive response with relief of pain. All of them underwent total hip replacement and remained pain free following surgery. In twenty-three patients intra-articular injection did not relieve the pain; three of these underwent successful total hip replacement two years later. Other negative responders were further evaluated and appropriately managed. This study confirms that intra-articular injection of local anaesthetic is a valuable tool in diagnostic dilemma. The calculated sensitivity of 88% and specificity of 100% is similar to other published series.