The Cortical Ring Sign: Clinical Results of Percutaneous Coracoclavicular Fixation

Background The coracoid cortical ring sign is a radiographical view that targets the coracoid base. We hypothesized that the use of this view to treat acromioclavicular separations would achieve desirable results with a rapid, percutaneous procedure. Methods Percutaneous coracoclavicular screws, guided by the cortical ring sign view, were used to treat acute, Rockwood grade III or greater acromioclavicular separations with instability to cross-body adduction. The anaesthesia database, clinical and radiographical outcomes were retrospectively reviewed for 41 cases (average age 35 years, range 18 years to 78 years). Average follow-up was 4.7 months (range 1 month to 23 months). Results There were six episodes of screw loosening (15%); three of six required an additional surgical procedure. The average residual joint subluxation at final follow-up was approximately 40%, which was significantly improved from the pre-operative displacement (p < 0.01) and not statistically different from the reduction achieved with the screw in place. All patients had full range of motion and, using the modified UCLA score, 98% (40/41) achieved ‘Good to Excellent’ results. The procedure was rapid (average surgical time: 35 minutes), minimally invasive (average blood loss: 15 mL), and the coracoid cortical ring sign view averaged less than 5 minutes to localize. Conclusion When using the coracoid cortical ring sign to target a coracoclavicular screw, the procedure is rapid, minimally invasive, and clinically predictable. There is, however, a high rate of screw loosening and subluxation.