Effectiveness of the saline load test in diagnosis of traumatic elbow arthrotomies

The purpose of this study was to investigate the amount of fluid required and the sensitivity of the saline load test to identify an intra-articular arthrotomy of the elbow.

A cadaveric study was conducted using 36 thawed, fresh-frozen forequarter amputations. An elbow arthrotomy was made in the posterocentral arthroscopic portal site with a 4.5-mm trochar. To confirm intra-articular location of the arthrotomy, the trochar was trapped in the ulnohumeral joint. The elbow joint was then loaded with saline mixed with methylene blue. During the injection, the known arthrotomy site was observed for leakage. If no leakage occurred after loading 20 mL of fluid, the elbow was taken through a range of motion. If still no leakage was appreciated at the arthrotomy site, the elbow was again infused with fluid in 2 mL increments until outflow. All injections were confirmed as intra-articular by demonstrating methylene blue staining of the anterior joint by open exploration.

A positive result was obtained in 26 of the 36 elbows (72% sensitivity) with injection of 20 mL of fluid, and with the addition of range of motion, another 5 elbows demonstrated leakage, raising the sensitivity to 86%. However, to identify 95% of arthrotomies, a total of 40 mL of fluid had to be injected.

Our results demonstrate that 40 mL of fluid must be injected to identify the majority of traumatic arthrotomies about the elbow. Moreover, adding range of motion after the injection increases the detection rate.