Tendon Graft—Ulna Fixation in Distal Radio-Ulnar Joint Stabilisation; Biomechanical Comparison of three Graft-Bone Fixation Methods

Abstract

A common distal radio-ulnar joint (DRUJ) stabilisation procedure uses a tendon graft running from the lip of the radial sigmoid notch to the ulnar fovea and through a bony tunnel to the ulnar shaft, before being wrapped round the distal ulna and sutured to itself. Such graft fixation can be challenging and requires a considerable tendon length. The graft length could be reduced by fixing the graft to the ulna using a bone anchor or interference screw. The aim of this study was to compare the strength of three distal ulna graft fixation methods (tendon wrapping and suturing, bone anchor and interference screw). Four human cadaveric ulnae were used. A tendon strip was run through a tunnel in the distal ulna and secured by: (1) wrapping round the shaft and suturing it to itself, (2) a bone anchor and (3) an interference screw in the bone tunnel. Load to failure was determined using a custom-made apparatus and an Instron machine. Maximum failure load was highest for the bone anchor fixation (99.3 +/- 23.7 N) followed by the suturing (96.2 +/- 12.1 N), and the interference screw fixation (46.9 +/- 5.6 N). There was no significant difference between the tendon suturing and bone anchor methods, but the tendon suturing was statistically significantly higher compared to the interference screw (P = 0.028). In performing anatomical stabilisation of the DRUJ fixation of the tendon graft to the distal ulna with a bone anchor provides the most secure fixation. This may make the stabilisation technique less demanding and require a smaller tendon graft.

Outcomes of the Adams–Berger Ligament Reconstruction for the Distal Radioulnar Joint Instability in 95 Consecutive Cases

“…Kalson et al biomechanically tested tendon graft fixation methods in the Adams-Berger procedure. 24 They found that the maximum load to failure of the original suture method of tendon graft fixation was equal to bone anchor suture fixation, which were both superior to an inference screw. This mirrors our clinical results.…”