Biomechanical Comparison of Fracture Risk Created by 2 Different Clavicle Tunnel Preparations for Coracoclavicular Ligament Reconstruction

Abstract

Background:An anatomic reconstruction of coracoclavicular (CC) ligaments typically requires drilling tunnels in the clavicle. An increase in fracture complications has been associated with graft tunnel position. A method of drilling clavicle tunnels that would better re-create anatomic function of the CC ligaments without increasing fracture risk would be an improvement.Purpose:To evaluate the feasibility of a novel single anterior-to-posterior tunnel technique and compare the biomechanical properties to the 2-tunnel technique in CC ligament reconstruction. The hypothesis was that the single tunnel will yield similar loads to failure as the 2-tunnel technique and better reproduce the native anatomy of the conoid and trapezoid ligaments.Study Design:Controlled laboratory study.Methods:Eight fresh-frozen matched pairs of human clavicles underwent testing. In 1 specimen of the matched pair, 2 bone tunnels were created as previously described. In the other, a single tunnel was placed obliquely from anterior to posterior. The relative position of the tunnels in relation to the conoid tuberosity was recorded. Specimens were tested on a materials testing machine. The ultimate load to failure, linear stiffness, distance of the conoid tuberosity to the conoid tunnel exit point, and mode of failure were recorded.Results:The ultimate load to failure in the single-tunnel group and the 2-tunnel group was 457.2 ± 139.8 and 488.8 ± 170.6, respectively. There was no significant difference (P = .5). The linear stiffness in the single-tunnel group and the 2-tunnel group was 94.6 ± 31.3 and 79.8 ± 33.5, respectively. There was no significant difference (P = .2). The 2-tunnel group had a significantly longer average maximum distance from the conoid tuberosity to the conoid tunnel exit point than the single-tunnel group (6.0 ± 2.1 vs 0.8 ± 1.9 mm; P = .05). The single-tunnel group was consistently more anatomic with regard to its relationship to the conoid tuberosity than the 2-tunnel group.Conclusion:The single anterior-to-posterior clavicle tunnel had similar biomechanical properties to the 2-tunnel technique. However, the single-tunnel technique better reproduced the anatomic footprint of the conoid ligament. Utilizing this single-tunnel technique may yield an anatomic advantage that may also reduce the rate of complications caused by posterior wall blowout.Clinical Relevance:Acromioclavicular joint injuries are common in collision sports. Surgical management is often indicated to reconstruct the joint. This study assesses the feasibility of a novel surgical approach.

Biomechanical Evaluation of a Single- Versus Double-Tunnel Coracoclavicular Ligament Reconstruction With Acromioclavicular Stabilization for Acromioclavicular Joint Injuries

“…To our knowledge, a handful of other ST CC ligament reconstruction techniques have been described. 6,16,21,24,32 Some favorable results were published, but the overall outcomes are mixed. Beitzel et al 4 performed a biomechanical study in 2011 in which the ST CC ligament reconstruction technique (1 suture pulley and 2 buttons) and the DT CC ligament reconstruction technique (1 suture pulley and 3 buttons) demonstrated a high load to failure, with superior translation equal to the stability of a native AC joint.…”

Arthroscopically Assisted Comprehensive Double Cerclage Suture Fixation Technique for Acute Acromioclavicular Joint Separation

“… 14 In that context, some authors preconized the use of a single-tunnel technique because, despite the high success rates of double-tunnel anatomical techniques, it can be a more suitable option to minimize fracture risk. 15 , 16 , 17 …”

A technique for a more accurate and convenient in coracoclavicular ligament reconstruction of acromioclavicular joint dislocation

“…The CC ligament include the conical ligament and the trapezoid ligament, while is an important structure against the upward and backward displacement of the distal clavicle [21]. Although studies have shown that the double tunneling technique is more suitable for the anatomical reconstruction of CC ligament, the single tunneling technique has less damage to clavicle and coracoid bone, which can reduce the risk of iatrogenic fractures and is more suitable for short stature, women or Asians [22][23]. Patzer et al [24] also demonstrated that there was no significant difference in the clinical efficacy of single-Tight-Rope and double-Tight-Rope techniques in the treatment of Rockwood 3 and 4 injuries.…”