Ulnar Collateral Ligament Thickness Varies After Reconstruction

Ulnar collateral ligament reconstruction results in varied thickness that differs from the anatomical ulnar collateral ligament (UCL), a new study finds.

In “Professional Pitchers Display Differences in UCL Morphology and Elbow Gapping During Moving Valgus Stress Testing After UCL Reconstruction,” published online on November 1, 2021 in the Orthopaedic Journal of Sports Medicine, the researchers measured ulnar collateral ligament thickness.

“Ulnar collateral ligament reconstruction of the elbow has received much attention given the rise in incidence among baseball pitchers. Stress ultrasonography has been demonstrated to be a critical evaluation tool of the ulnar collateral ligament. No study has dynamically evaluated the ability of ulnar collateral ligament reconstruction [UCLR],” the researchers wrote.

They hypothesized that the ulnohumeral joint would display greater gapping and the ulnar collateral ligament graft will be thicker in pitchers after ulnar collateral ligament reconstruction compared with uninjured pitchers.

Pitchers with a history of UCLR demonstrated less gapping (5.6 ± 2.9 vs 4.2 ± 1.2 mm; p = .002) and greater UCL graft thickness (0.17 ± 0.07 vs 0.11 ± 0.08 mm; p = .03) compared with the native ligament in pitchers without prior ulnar collateral ligament injury.

The researchers used ultrasonography to measure the medial ulnohumeral joint distance and the ulnar collateral ligament thickness of 70 asymptomatic professional baseball pitchers, 6 of whom had a history of ulnar collateral ligament reconstruction.

They took images of the dominant and nondominant elbows at the maximal cocking position under 2 loaded conditions with the moving valgus stress test arc: gravity stress and 2.5 kg (5.5 lb) of valgus force using a dynamometer.

The researchers wrote, “Our data demonstrated that the ulnar collateral ligament reconstruction results in a thicker, stiffer construct with less medial elbow gapping than the anatomical ulnar collateral ligament. Using ultrasound to evaluate the ulnar collateral ligament was a reliable, efficient, and clinically feasible method to assess ulnar collateral ligament thickness and joint gapping in players with a history of ulnar collateral ligament reconstruction. Future studies may consider this approach to evaluate surgical techniques and graft types of ulnar collateral ligament reconstruction.”

The study authors included Michael J. Kissenberth, M.D. of the Prisma Health Steadman Hawkins Clinic of the Carolinas and the Hawkins Foundation, Charles A. Thigpen of the Hawkins Foundation and ATI Physical Therapy, Lane Brooks Bailey of Memorial Hermann Ironman Sports Medicine Institute in Houston, Texas, Joel Campbell, M.D. of Prisma Health Steadman Hawkins Clinic of the Carolinas, Derik J. Geist, M.D. of West Virginia University, Mark L. Schweppe, M.D. of Novant Health in North Carolina, Douglas J. Wyland, M.D. of Prisma Health Steadman Hawkins Clinic of the Carolinas in South Carolina, Richard J. Hawkins, M.D. of Hawkins Foundation, Thomas J. Noonan, M.D. of Steadman Hawkins Clinic Denver in Greenwood Village, Colorado, and Ellen Shanley of the Hawkins Foundation and the ATI Physical Therapy.