Surgical treatment of chronic acromioclavicular dislocation with biologic graft vs synthetic ligament: a prospective randomized comparative study

Abstract

Background: Acromioclavicular (AC) dislocation involves complete loss of articular contact; it is defined as chronic when it follows conservative management or unsuccessful surgical treatment.

Materials and methods: The study compared the clinical and radiographic outcomes of AC joint stabilization performed in 40 patients with chronic dislocation using a biological allograft (group A) or a synthetic ligament (group B). Demographic data included: M/F: 25/15; mean age: 35 ± 3.2 years; previous surgery in 11 patients, including Weaver-Dunn (3), coracoacromial ligament repair (4), stabilization with K-wires (4). Dislocation was type III in 14 (35 %) and type IV in 26 (65 %) patients. Clinical assessment was with the Constant-Murley score (pre- and postoperative) and with the modified UCLA score. Enrollment started in January 2004 and was completed in March 2008. Patients were evaluated at 1 and 4 years. Postoperative X-rays were examined to assess joint stability in the coronal and axial planes, coracoclavicular ossification, and signs of AC joint osteoarthritis and distal clavicular osteolysis.

Results: The "biological" group achieved significantly better clinical scores than the "synthetic" group at both 1 and 4 years. Poor subjective satisfaction and lower clinical scores were found in the 3 patients (1 from group A and 2 from group B) who experienced complete postoperative dislocation. No significant correlations were found with other radiographic parameters.

Conclusions: The biological graft afforded better clinical and radiographic outcomes than the synthetic ligament in patients with chronic AC joint instability. Fixation to the clavicle constitutes the main weakness of both approaches and needs improving.

Fig. 1

Complete AC joint dislocation, right shoulder (type IV of Rockwood et al. [4])

Fig. 2

Intraoperative image showing the biological graft as it is being passed under the base of the coracoid and through the holes in the clavicle after AC joint reduction. C coracoid, CH clavicular holes, TG tendon graft, A acromion

Fig. 3

Intraoperative image showing the synthetic ligament (LARS LAC^®, Arc sur Tille, France) as it is being passed under the coracoid and through the clavicular holes

Fig. 4

Postoperative X-rays: left AC joint stabilized with the biological graft

Fig. 5

Postoperative X-rays: complete dislocation after stabilization with the biological graft. Note the coracoclavicular ossification

Fig. 6

Clavicular osteolysis around the screws in a stable AC joint treated with the biological graft

Fig. 7

Postoperative X-rays: left AC joint stabilized with the synthetic ligament (LARS LAC^®)

Fig. 8

Distal clavicular fracture, osteolysis and screw loosening in a patient treated with the synthetic ligament (LARS LAC^®)