Effect of ulnar tunnel location on elbow stability in double-strand lateral collateral ligament reconstruction

Risk factors associated with atraumatic posterolateral rotatory instability

Background

Traumatic posterolateral rotatory instability after elbow dislocation or fracture dislocation has been well described. However, few reports cover atraumatic posterolateral rotatory instability as a cause of lateral-sided elbow pain. We assessed the risk factors and epidemiology of atraumatic posterolateral rotatory instability in a case-control study.

Methods

A retrospective review of all patients treated operatively for atraumatic posterolateral rotatory instability during a 6-year period was compared with a group of patients with extensor carpi radialis brevis tendinopathy without instability treated during the same time period. Bivariate and multiple logistic regression statistical analyses were used to investigate the following risk factors: gender, age, hand dominance, diabetes, smoking, body mass index, corticosteroid injection history, and duration of symptoms. Disabilities of the Arm, Shoulder, and Hand and pain scores were obtained preoperatively and postoperatively.

Results

Thirteen patients with atraumatic posterolateral rotatory instability were compared with 12 patients with extensor carpi radialis brevis tendinopathy. Multivariate analysis revealed patients with atraumatic posterolateral rotatory instability were more likely to have multiple corticosteroid injections (P = .05) and present with a longer duration of symptoms (P = .03). Postoperative pain scores improved in both groups.

Conclusions

Atraumatic posterolateral rotatory instability should be considered in the differential diagnosis of lateral elbow when patients present with a protracted clinical course. Statistically, posterolateral rotatory instability patients more often present with a history of multiple corticosteroid injections.

Three-dimensional computed tomography modeling for kinematic analysis of double-strand lateral ulnar collateral ligament reconstruction

BACKGROUND

When treating posterolateral rotatory instability, the lateral ulnar collateral ligament (LUCL) is more commonly reconstructed than the other dynamic stabilizer structures. Although numerous surgical techniques have been described for LUCL reconstruction, studies have been limited to static analyses of single-strand reconstructions. The aim of this study was to dynamically analyze the kinematics of double-strand LUCL reconstructions with 3 different configurations of graft placement: horizontal, vertical, and triangular.

METHODS

Five healthy elbow joints with no signs of pre-existing pathology were scanned by computed tomography, and the images were converted into 3-dimensional models. The humeral origin and ulnar insertions of the 2 ligament strands were registered in 3-matic software for the 3 graft placement configurations. A dynamic elbow joint was simulated at 1° increments throughout the motion arc. The ligament strand lengths and the difference between them were measured.

RESULTS

The ligament lengths for each strand for the 3 graft configurations were as follows: horizontal, 31.0 ± 4.6 mm and 34.3 ± 5.0 mm; vertical, 32.5 ± 3.6 mm and 35.4 ± 4.2 mm; and triangular, 32.0 ± 4.0 mm and 33.7 ± 3.1 mm. The minimum length differences for the graft strands through the motion arc for the horizontal, vertical, and triangular graft configurations were 1.1, 0.0, and 1.0 mm, respectively.

CONCLUSIONS

Dynamic analyses using a 3-dimensional elbow model showed that none of the configurations for double-strand LUCL reconstruction were isometric. However, the vertical double-strand configuration was nearly isometric and may therefore serve as a coequal option.

Complex Case of Open Fracture-Dislocation of the Elbow

Complex elbow instability is difficult to surgically address. Careful consideration of the fractures and soft tissue injuries is required. We present the case of a patient who sustained an open fracture-dislocation of the elbow with significant loss of the external humeral condyle and partial loss of the olecranon. He was surgically treated with an iliac crest tricortical autograft fixed with a buttress plate and a lag screw. His lateral ulnar collateral ligament was reconstructed with tendinous autograft collected from his third and fourth extensor digitorum longus tendons. While the procedure complicated with a Nocardia infection and wound breakdown, the patient almost had full range of motion without instability at 11 months of follow-up.