The most accurate approach for intra-articular needle placement in the knee joint: a systematic review.

INTRODUCTION: Intra-articular needle placement in the knee joint, such as injection or aspirations, are commonly used for therapeutic, diagnostic, and research purposes. Although several approaches can be used to establish an intra-articular injection or aspiration of the knee joint, the accuracy differs per approach.
OBJECTIVE: To summarize the evidence concerning the accuracy of different approaches for intra-articular needle placements in the knee. Additionally, to assess whether the accuracy of different approaches is related to factors such as underlying disease, severity of underlying disease, approach-related factors, and/or the rate of local reactions.
METHODS: The literature was systemically reviewed until July 2010. Risk of bias of the included studies was assessed by the QUADAS tool. Study characteristics were extracted; accuracy results were pooled per approach.
RESULTS: Nine studies were included. The superolateral approach with the leg in extension was studied most (230 injections) and resulted in the highest pooled accuracy of 91% (95% CI 84-99%). The lateral midpatellar approach, the anterolateral approach, and the anteromedial approach resulted in the lowest pooled accuracy rates, 85% (95% CI 68-100%), 67% (95% CI 43-91%) and 72% (95% CI 65-78%), respectively.
CONCLUSIONS: The superolateral approach was investigated most and resulted in the highest pooled accuracy rate of 91% (95% CI 84-99%). Nevertheless, this approach still results in a substantial amount of extra-articular needle placements. Guidance of intra-articular needle placements by imaging techniques may enhance the accuracy. The costs and extra time associated with these techniques should be taken into consideration.