Epithelial tissue cut-out following needle insertion into a joint: a potential complication during arthroscopy

Knee arthroscopy is a common orthopaedic procedure and often involves insertion of a needle through skin into a joint. This needle insertion can create epithelial tissue cut-outs possibly containing commensal bacteria that can be flushed into the joint, and potentially lead to post-arthroscopy septic arthritis. This study aims to assess the frequency of epithelial tissue cut-out creation on insertion of different needle sizes at different angles to the skin.

Using an ex-vivo porcine limb tissue model, needles of various gauge (14-23G) were inserted at angles of 90, 60, 45 and 30° to the skin surface. Ten passes were undertaken at each angle. Needle lumen contents were then examined for solid tissue cut-out.

Two hundred and eighty needle passes were performed resulting in 70 tissue cut-outs (25%) containing solid material. This was more common amongst lower gauge needles. 8 of the 70 (11.4%) tissue cut-outs contained macroscopic evidence of epithelium. The overall rate of epithelial tissue cut-out was 2.9%. The 23G needle had the lowest rate of tissue cut-out creation, occurring twice out of 40 passes (P = 0.002). Neither of these contained macroscopic epithelial tissue.

Hypodermic needle insertion through skin into a joint can create epithelial tissue cut-out. Epithelial tissue cut-out occurs more frequently with use of lower gauge needles. This study suggests use of a 23G needle during arthroscopy, inserted either at 60 or 90° to the skin, to reduce epithelial tissue cut-out and any potential contribution to post-arthroscopy septic arthritis.