This retrospective study was approved by the institutional review boards of the hospitals involved in accordance with international agreements (World Medical Association Declaration of Helsinki “Ethical Principles for Medical Research Involving Human Subjects,” amended in October 2013, www.wma.net). Informed consent and Health Insurance Portability and Accountability Act consent were obtained from each patient.
From January 2015 to January 2019, 43 patients with Rockwood III to VI acute AC dislocations were retrospective reviewed. The diagnosis was established according to the proper history taking, physical examination, and X-ray. Increase of CC distance of 25% to 50% over the normal side on a bilateral Zanca view indicated complete CC ligament disruption.
Our eligibility criteria were: (1) patients aged between 18 and 65 years; (2) an acute AC dislocation within 14 days; (3) Rockwood grade III to VI; (4) normal opposite upper limb for comparison. Our exclusion criteria were as follows: patients younger than 18 years were excluded because of skeletal immaturity (n=3); patients older than 65 years are excluded because of possible osteoporosis (n=1); combined fractures of the joints (n=1); old AC dislocations exceeding 14 days because the treatments may be different; discontinued intervention (n=4); and declined to participate (n=2). Finally, a total of 32 patients were enrolled in this study. All operations were performed by the same senior orthopaedic surgeons.
Surgical Technique
The operation was performed with the patient under general anesthesia. The patients was placed in the beach chair position or supine position with extra padding under the injured shoulder. An 8-cm curved incision was made from the AC joint to the distal anterior clavicle. The base of the coracoid process, AC joint, and distal clavicle were visualized. One coracoid tunnel (#1), four clavicle tunnels (#2, #3, #4, and #5), and two acromion tunnels (# 6 and #7) were drilled using a 2.0 mm pin (Fig. 2A). The lateral clavicle was reduced by manipulation (Fig. 2B), and maintained using pointed reduction clamps or a K-wire as needed. We passed two 2/0 braided nonabsorbable polyester sutures (Ethicon, INC., Somerville, NJ, USA) through the coracoid tunnel (#1) using a 1 mm stainless steel wire loop (Fig. 3A). The two free limbs of each suture were passed through the loop of the same suture, and then tightened over the coracoid (Fig. 3B). The four limbs were tied together, and then passed through the clavicle tunnels (#2, #3, #4, and #5) separately to reconstruct the CC ligament (Fig. 3C). Two of the limbs were tied to the corresponding pair (Fig. 3D, E). Two limbs passed through the acromion tunnels (# 6 and #7) and another two limbs were tied together over the acromion to reconstruct the AC ligament (Fig. 3F). The ruptured AC, CC, and coracoid ligaments, as well as the capsule were repaired if possible (Fig. 3G, H). The temporary maintenance was removed, and the AC reduction was confirmed on X-ray (Fig. 3I). The wound was closed in layers.
Postoperative managements
After surgery, the limb was supported with a platform brace for 6 weeks to minimize the gravity-induced stress on the AC joint. Gentle passive range of motion was started after 6 weeks. Strength exercises for the scapular muscle were started after 12 weeks.
Outcome Evaluation
Active motions of the shoulder were measured with a goniometer, and all measurements were compared to those on the opposite limb. On the frontal X-ray of the shoulder, the CC space (distance between the superior cortex of the coracoid process and the undersurface of the clavicle) was assessed 8. Loss of reduction was defined as >25% increase of CC distance developed. The AC space was also assessed. Grip strength of the hand was measured using a dynamometer. To improve consistency between dominant and nondominant grip strength, we based the scores for analysis on the premise that the grip strength was 6% higher at dominant sides compared with the nondominant sides 9. We used the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire 10 to assess the limb function. Clinical evaluation of patients was performed using the University of California-Los Angeles (UCLA) 11 scoring systems. The UCLA score consisted of pain (0–10 points), function (0–10 points), range of motion (0–5 points), strength (0–5 points), and the patient’s satisfaction (0–5 points). The total UCLA score is 35 points, and 34 points or 35 points, 29 points to 33 points, and ≤ 29 points indicate excellent, good, and poor results, respectively.
Statistical Analysis
Quantitative variables were described as mean and ranges. The collected data were analyzed with the Statistical Package for Social Sciences 19.0 (SPSS, Inc., Chicago, Ill). A P<0.05 was considered statistical significance.