Biomechanical comparison of lateral collateral ligament reconstruction with and without additional internal bracing using a three-dimensional elbow simulator

No difference in torque load to failure between split anconeus fascia transfer and autograft palmaris longus tendon for reconstruction of the lateral ulnar collateral ligament

Background

The split anconeus fascia transfer (SAFT) is an option for reconstruction of the lateral ulnar collateral ligament (LUCL) in chronic posterolateral rotatory instability (PLRI) of the elbow with potential advantages of using only local tissue within the surgical exposure and not requiring ulnar fixation. This study aimed to assess SAFT strength compared to a traditional free graft reconstruction in a PLRI biomechanical model.

Methods

To measure biomechanical strength, eight cadaveric upper extremity pairs were utilized. Within each pair, one specimen was randomly assigned to LUCL reconstruction with autograft palmaris longus and the other to SAFT reconstruction. Torque load to failure was assessed on a load frame with the elbow in 30 degrees of flexion, 5 degrees of valgus, and 25 N axial load as the elbow was brought into external rotation. Torque load to failure was compared between the two reconstruction techniques.

Results

No difference was found in the torque load to failure between SAFT specimens compared to palmaris longus autograft specimens (mean 14.6 ± 4.4 Nm vs. mean 11.3 ± 3.9 Nm; P = .16).

Discussion

In this biomechanical study, the SAFT LUCL reconstruction provided torque load to failure similar to that of the traditional technique. These findings suggest that the SAFT technique warrants continued study as a biomechanically sound option for LUCL reconstruction in the setting of elbow PLRI.

[Augmented primary sutures "internal bracing" following ligamentous elbow dislocation]

OBJECTIVE

Aim of surgical treatment is the primary stabilization of the unstable elbow following a ligamentous elbow dislocation.

INDICATIONS

Ligamentous elbow dislocations are typically accompanied by injuries to the surrounding musculature and collateral ligaments of the elbow joint. Surgical treatment is indicated in case of failure of nonoperative therapy, i.e., when a dislocation can only be prevented in immobilization > 90° and pronation of the elbow or an active muscular centering of the elbow fails after 5-7 days.

CONTRAINDICATIONS

Contraindications for a solely "internal bracing" augmented primary suture are generally in the case of accompanying bony injuries in elbow dislocations, extensive soft-tissue injuries, and septic arthritis of the elbow.

SURGICAL TECHNIQUE

The augmented primary suture of the elbow is performed using both a lateral (Kocher or Kaplan) and medial (FCU split) approach to the elbow. After reduction of the elbow, the collateral ligaments are first augmented with high-strength polyethylene suture and fixed in the distal humerus together with another high-strength polyethylene augmentation suture. The extensors and flexors are then fixed to the medial and lateral epicondyle, respectively, using suture anchors.

POSTOPERATIVE MANAGEMENT

The aim of the postoperative management is early functional exercise of the elbow. The elbow is placed in an elbow brace to avoid varus and valgus load.

RESULTS

Between August 2018 and January 2020, a total of 12 patients were treated with an augmented primary suture following unstable ligamentous elbow dislocation. After a mean follow-up of 14 ± 12.7 months, the mean Mayo Elbow Performance Score was 98.5 points with a mean functional arc of 115°. None of the patients reported a recurrent dislocation or persistent instability of the elbow.