Anatomical dimensions of anterior bundle of ulnar collateral ligament and its role in elbow stability.

Objective: To study the anatomical dimensions of the anterior bundle of ulnar collateral ligament and its role in elbow instability.

Methods: We studied 20 elbows of 10 cadavers. Anterior bundle of ulnar collateral ligament was dissected in all elbows and its anatomical length and width were measured. After measuring it, we assessed the role of the anterior bundle of ulnar collateral ligament in the medial elbow joint stability, with the capsule, the radial head and anterior bundle of ulnar collateral ligament being cut.

Results: The mean right length of the anterior bundle of ulnar collateral ligament was 21.10 +/- 6.29 mm and the mean left length was 21.70 +/- 5.31 mm. The mean right width of the anterior bundle of ulnar collateral ligament was 12.70 +/- 2.79 mm and the mean left width was 13.90 +/- 2.37 mm. Anterior bundle of ulnar collateral ligament was found to be the main stabilizer of the valgus stress. The anterior capsule and the radial head also make contributions to this stability. However, when anterior bundle of ulnar collateral ligament is cut, the radial head and the anterior capsule fails to maintain the stability against valgus stress.

Conclusions: The anatomical dimensions of the anterior bundle of ulnar collateral ligament are important for a surgeon when graft is used in reconstructing this ligament. Our study is an initiator of this topic and we believe that with larger series, more reliable anatomical measurements can be obtained. We also showed that the anterior bundle of ulnar collateral ligament is the main medial stabilizer of the elbow joint.