Arteriovenous Fistula Formation After Intra-articular Injection Following Total Joint Arthroplasty.

Intra-articular joint capsule injection is a common method used to control postoperative pain as a result of primary total knee arthroplasty (TKA). It is generally considered a safe practice and is highly effective in reducing the need for postoperative opioid administration as well as decreasing recovery time through early mobilization. However, any injection into the posterior knee space has the potential to injure the vascular structures surrounding the knee. Iatrogenic formation of an arteriovenous fistula is a rare complication after TKA, and there are no reported cases of arteriovenous fistula formation as a direct result of intra-articular injection. This case report describes this complication that occurred several days after TKA. The patient had acute pain and swelling in the treated leg. An arteriovenous fistula of the popliteal artery and vein was identified with bilateral Doppler ultrasound and confirmed by angiogram. The most likely inciting event for the formation of the arteriovenous fistula was intra-articular injection of bupivacaine, which likely pierced the popliteal artery and vein, allowing the formation of the patent channel. The patient was treated successfully with stent placement through interventional radiology. Orthopedic surgeons performing intra-articular injections of the knee should refamiliarize themselves with the anatomy and location of the popliteal artery, use smaller-gauge needles, and aspirate the syringe before the injection to decrease the risk of iatrogenic damage to the vasculature or fistula formation. [Orthopedics.2016; 39(5):e976-e979.].