Failure of Coracoclavicular Artificial Graft Reconstructions From Repetitive Rotation

PurposeTo assess how suture type and suture construct in an augmented Weaver-Dunn reconstruction affect coracoclavicular sling failure and rotary stability.MethodsFifteen cadaveric shoulders were tested in rotation about the long axis of the clavicle with 10 lb of simulated arm weight. The clavicle was rotated 50° about its long axis, and the applied torque was recorded. Next, modified Weaver-Dunn reconstruction was conducted. Two types of coracoclavicular sling (opposed drill holes through the clavicle and complete loop around the clavicle) were tested by use of 3 different sutures (FiberWire [Arthrex, Naples, FL], Mersilene tape [Ethicon, Somerville, NJ], and braided polydioxanone [PDS] [Ethicon]). For each sling-suture combination, the joint was retested over 50° of rotation and then cycled over 40° of rotation for 15,000 cycles or until failure.ResultsAfter modified Weaver-Dunn reconstruction with either sling construct, mean torque over 50° of acromioclavicular rotation was significantly reduced in posterior (P < .0001) and anterior (P < .0001) rotation, with any suture material tested. When the coracoclavicular sling was placed through opposed drill holes, no wear to the bone or suture was observed. When the sling material was looped around the clavicle, FiberWire and PDS resulted in abrasion of soft tissue and periosteum. In all cases sawing motion between bone and suture was observed at the coracoid. The FiberWire itself failed at a mean of 8,213 cycles. Some wear was noted in the Mersilene tape. PDS suture showed no wear.ConclusionsIn a cadaveric model of modified Weaver-Dunn reconstruction, a coracoclavicular suture loop was used to augment coracoacromial ligament transfer. Suture loops secured around the entire clavicle were shown to contribute to increased abrasive wear. Securing suture loops through opposed drill holes in the clavicle resulted in decreased abrasive wear.Clinical RelevanceProper selection of suture type and suture construct may affect the failure rate of augmented Weaver-Dunn reconstructions.