2015 ISAKOS Biennial Congress ePoster #2121

Factors Affecting Auality of Acromioclavicular Joint Reduction in Arthroscopic Indirect Coracoclavicular Fixation Technique

Yon-Sik Yoo, MD, PhD, Hwaseong-Si, Gyeonggi-do KOREA, REPUBLIC OF
Kyu-Cheol Noh, MD, PhD, Prof., Seoul KOREA, REPUBLIC OF
Byung-Su Kim, MD, Hwaseong-Si, Gyeonggi-Do KOREA, REPUBLIC OF
Seong-jin Lee, Kyeongkido KOREA, REPUBLIC OF

Hallym University, Seoul, Seoul, KOREA

FDA Status Not Applicable

Summary: Precise selection of tunnel location on clavicle is crucial to achieve an anatomical AC joint reduction in grade III and V acromioclavicular joint dislocations




It has been known that the majority of surgical methods for acromioclavicular dislocation had a relatively high chance of reduction loss over time. Patients with good sustainability of reduction after surgery would have better subjective and objective outcomes at long term follow up. In this context, arthroscopic indirect coracoclavicular fixation technique using flip button is a promising strategy which can provide strong fixation strength with minimal invasiveness and less morbidity. However, there are no exact guidelines which allow perfect reduction of AC joint


The aim of this study was to determine the factors associated with a high quality of reduction in arthroscopic indirect flip button fixation technique for the treatment of AC joint dislocation.


The study included 47 patients who had a successful restoration of CC interval on plain x-ray after arthroscopic indirect fixation using tightrope system. All patients were imaged with CT of a 1 mm helical scan. Digitally reconstructed radiographs were created from the CT scans using Amira software. We evaluate the three dimensional accuracy of reduction, tunnel positions of clavicle/coracoids, type of dislocation. An accuracy of reduction was subjectively graded as either high or low quality. The clavicle/coracoid tunnel positions were evaluated using grid system outlined between 20 mm to 40 mm from the lateral end of clavicle and 5 mm to 20 mm from the posterior cortex of the lateral clavicle along the long axis of distal clavicle. The grid on clavicle works by dividing the superior surface of distal clavicle into 6 different regions: UL (upper lateral), ML (middle lateral), BL (bottom lateral), UM (upper medial), MM (middle medial), and BM (bottom medial). Grid on coracoid process was divided into 3 regions (medial, center, and lateral) for tunnel placement as assessed by Ferreira et al. Exclusion criteria included delayed surgery over 1 month from initial injury. Logistic regression analysis was performed, with accuracy of reduction as the dependent variable and tunnel location, type of dislocation and timing of surgery as the independent variables.


The overall rate of high quality of reduction was 53.2% (25/47) at immediate postoperative CT finding. Of 25 shoulders with high quality of reduction, 18 shoulders had clavicle tunnels located at middle column (ML and MM) with statistical significance (p<0.01).
However, there were no statistical difference between clavicle tunnels on medial (UM,MM, BM) and lateral column (UL,ML,BL) (p=0.43). Likewise, no statistical difference were found among types and between coracoid tunnel locations (p>0.05)
Logistic regression analysis showed that the quality of reduction was correlated with clavicular tunnel location (correlation coefficient, r = 0.53; P < .001). Coracoid tunnel location and type of dislocation were not associated with quality of reduction.


Clavicular tunnels along the long axis of distal clavicle were the best intraoperative predictor of high quality of reduction during arthroscopic indirect coracoclavicular fixation using flip button device. However, this technique is not recommendable for type IV dislocation although we failed to reach an agreement to statistical significance due to a small numbers of type IV