Arthroscopic evaluation for posterolateral rotatory instability of the elbow.

OBJECTIVE

The purpose of this study was to evaluate the sensitivity of three arthroscopic techniques for intraoperative assessment of posterolateral rotatory instability (PLRI).

METHODS

The study was performed using six fresh frozen cadaveric upper extremities. The three arthroscopic tests were the modified ulnohumeral drive through test, the annular drive through test, and proximal radioulnar joint instrumentation. Sequential soft tissue sectioning was performed to create four stages of instability: baseline, transection of the anterior half of the lateral collateral ligament complex (i.e., the radial collateral ligament), transection of the posterior half of the LCL complex (i.e., the lateral ulnar collateral ligament), and finally the release of the common extensor origin. Each test was repeated with the elbow at 90-degrees flexion in neutral rotation and at 45-degrees extension in full supination.

RESULTS

Each test appropriately identified loss of the lateral ulnar collateral ligament. The modified ulnohumeral drive through test and the annular drive through test were most sensitive for loss of the radial collateral ligament. Elbow position did not affect test sensitivity.

CONCLUSIONS

Each of the tests identified PLRI with high sensitivity, regardless of elbow position. The ulnohumeral and annular ligament drive through tests were more sensitive for radial collateral ligament disruption.