Supination Peak Tourque After Inlay Versus Onlay Distal Biceps Reinsertion: A Randomized Controlled Trial

Purpose

Distal biceps brachii tendon (DBBT) rupture causes elbow weakness in forearm supination and flexion movements. Surgical treatment is indicated for young patients with high functional demands. This study aimed to evaluate forearm supination strength recovery after surgical repair with two different fixation techniques, onlay fixation with suture anchors and inlay with a bicortical button.

Methods

This was a single-center, prospective, randomized, controlled, study. A total of 40 patients with complete DBBT rupture were enrolled and allocated through block randomization before surgery to either receive onlay fixation (group A) or inlay fixation (group B). A single anterior incision approach was used for both groups. The forearm supination strength was measured using a digital dynamometer before surgery and at least 6 months postsurgery. Supination strength was evaluated on both forearms, with the tested elbow in 45°, 90°, and 120° degrees of flexion, and the forearm in a neutral position (0°).

Results

There was no statistically significant difference between the treatment groups in peak strength gained after surgery. No significant difference was found when the elbow was tested in the three different degrees of flexion. There was a decrease in supination peak torque of more than 50% compared to the control limb before surgery and a strength increase of ≥100% at follow-up after surgery was observed for both groups.

Conclusions

Onlay and inlay fixation techniques for surgical repair of DBBT rupture do not show significant differences in supination strength recovery and allow for excellent elbow function.

Type of study/level of evidence

Therapeutic I.