Background
The vascular supply of the ulnar collateral ligament (UCL) is unknown. Previous studies have reportedvarying success in patient return to play rates after non-operative management of partial UCL tears and suggest a varying healing capacity as possibly related to UCL injury location.
Purpose
To analyze the macroscopic vascular anatomy of the ulnar collateral ligament of the elbow.
Study Design: Descriptive laboratory study
Methods
Eighteen, fresh-frozen, male cadaveric elbows from nine donors were sharply dissected 15 cm proximal to the medial epicondyle. Sixty mL of India Ink was injected through the brachial artery of each elbow. Arms were then frozen at -10 °C, radial side down in 15-20° of elbow flexion. A bandsaw was used to section the frozen elbows into 5 mm coronal or sagittal sections. Sections were cleared for visualization using the modified Spalteholz technique. Images of specimens were taken and the qualitative description of the UCL vascularity was undertaken.
Results
We consistently found a dense blood supply to the proximal UCL, while the distal UCL was hypovascular. We observed a possible osseous contribution to the proximal UCL from the medial epicondyle in addition to an artery from the flexor/pronator musculature that consistently appeared to provide vascularity to the proximal UCL.
Conclusion
Our study found a difference in the vascular supply of the ulnar collateral ligament. The proximal UCL was well vascularized, while the distal UCL was hypovascular. This difference in vascular supply may be a factor in the differential healing capacities of the UCL based on the location of injury.
Clinical Relevance: An improved understanding of the macroscopic vascular supply of the UCL may aid in the clinical management of partial UCL tears and suggest an indication for these treatments with respect to location of UCL injuries.