The effect of arthroscopic sectioning of the lateral ligament complex of the elbow on posterolateral rotatory stability.

This study evaluates the relative roles of the radial collateral ligament, the lateral ulnar collateral ligament, and the overlying musculature in posterolateral rotatory instability of the elbow. Fourteen cadaveric upper limbs underwent sequential arthroscopic sectioning of the lateral collateral ligament complex. After sectioning, arthroscopic and fluoroscopic evaluation of a lateral pivot shift test was done. Minimal instability was noted after the first section, but no difference between radial collateral or lateral ulnar collateral ligament sectioning was found. A greater degree of instability was seen between the first and second cut ( P = .0001), but no significant difference was seen between sectioning the 2 groups ( P = .61). Complete instability occurred only after sectioning the overlying musculature. On the basis of this study, injury to both the radial collateral and lateral ulnar collateral ligaments is necessary to cause significant posterolateral rotatory instability of the elbow. Furthermore, the overlying musculature plays an important role in overall stability.