Intra-articular fluid volume and restricted motion in the elbow

Eleven fresh-frozen cadaveric upper extremities were studied to determine the effect of intra-articular fluid volume on the range of motion of the elbow. The flexion arc of the cadaveric elbows was measured before and after incremental injections of saline solution. Linear regression analysis showed that the relationship between the flexion arc and intra-articular fluid volume is linear up to a total volume of 25 mL. The flexion arc of motion decreased by a mean of 2.1° per milliliter of fluid injected. A mean volume of 10.8 mL of saline solution decreased the flexion arc to the point where surgery has traditionally been recommended for type II radial head fractures. On the basis of these findings, the use of post-aspiration range of motion should be reconsidered as a criterion for surgical treatment of radial head fractures.