Patients
This was a retrospective cohort study of teenage athletes who underwent ABR for traumatic anterior shoulder instability between January 2013 and January 2019 at a single institution by a single surgeon. Informed consent was obtained from all participants and their parents, and institutional review board approved this study (2020–008). All patients preoperatively underwent computed tomography (CT) of both shoulders, and the size of the bony defect of the glenoid was measured. The inclusion criteria were as follows: (1) age of 13–19 years at the time of surgery, (2) athletes who regularly played sports in the school team, local club, or work team at a competitive level; (3) athletes who aimed RTS after the surgery; (4) patients who underwent ABR with or without any additional intra-articular procedure such as bony Bankart repair, humeral avulsion of glenohumeral ligament (HAGL) repair, superior labrum anterior and posterior (SLAP) repair. We excluded patients who underwent remplissage procedure for large Hill–Sachs lesions [10], (5) patients with direct follow-up for more than one year after surgery, and indirect follow-up via telephone survey for more than two years after surgery. The exclusion criteria were as follows: (1) patients who decided to quit their sports before surgery, (2) patients with large bony defect of the glenoid, which is larger than 20% of the length of the healthy side [11]; in such cases, the modified Bristow procedure was performed in addition to ABR. The distinctive types of sport were divided into three groups according to Ide et al. [12]: contact sport, dominant overhead sport, and noncontact-nonoverhead sport. Contact sport includes sports in which bodies collide intensely with each other, such as rugby and soccer, as well as martial arts sports such as judo, wrestling, and boxing. The dominant overhead sport includes sports involving pitching such as baseball, and overhead sports using a racket such as a badminton, as well as sports in which overhead movements are repeated, such as volleyball, basketball, handball, and swimming. The noncontact-nonoverhead sport includes other sports and overhead sports in which the affected side is not dominant side.
Surgical procedure
Under interscalene block and general anesthesia, patients were placed in the lateral decubitus position with the affected arm placed in 20° abduction using 2-kg inferior traction and 2–3-kg lateral traction. A standard posterior portal was made in addition to the anterior and anterosuperior portals into the rotator interval. The anterior portal was located 1 cm laterally and 1 cm inferiorly from the coracoid process to make it easier to place the anchor at 6 o’clock. After the diagnostic assessment of intra-articular pathology, the inferior glenohumeral ligament labrum complex (IGHLLC) was completely mobilized from the glenoid. This mobilization was performed beyond the 6 o’clock position of the glenoid to induce re-tension in the IGHLLC. The glenoid neck was decorticated, and 4 to 7 suture anchors (JuggerKnot Soft Anchor 1.4-mm, Biomet Sports Medicine, Warsaw, IN) were inserted at the anteroinferior glenoid rim. The first anchor was placed close to the 6 o’clock position, using a curved guide. Viewing through the anterosuperior portal, a suture passer was introduced from the posterior portal, and the suture was passed through the capsule immediately inferior to the first anchor. The viewing portal was changed to the posterior portal, and the suture was tied to grasp and pull up the IGHLLC. The following suture anchors were superiorly inserted at one o’clock intervals, and the same procedures were repeated two to five times (Fig. 1). If a large bony Bankart was present, the double-row technique was used. In this technique, one or two suture anchors were inserted at the glenoid neck at 3 to 5 o’clock, and the sutures were passed through the capsule and the bony fragment and fixed at the glenoid rim using a knotless anchor (2.4 mm PushLock anchor, Arthrex, Naples, FL) (Fig. 2). If HAGL, SLAP lesions, or posterior labral tears were concomitant, additional suture anchors were used for repair. Rotator interval closure was not applied in any of the cases.
Postoperative management
All patients followed the same postoperative rehabilitation protocol under the supervision of one of the authors. A shoulder sling was used for four weeks. Isometric strengthening was initiated one day after surgery. After two weeks, self-assisted elevation training was initiated. Active elevation and abduction exercises were started at 3 and 4 weeks after the surgery, respectively. Sports activity was gradually started from 3 months, and overhead motion or contact play was permitted at 6 months. Return to play was permitted when the patient was pain-free and the range of motion and muscle strength had been restored to almost the same level as the healthy side.
Clinical evaluation
The data on preoperative assessment, including age at surgery, sex, dominant side, number of preoperative instability episodes, the time from the first injury to surgery, and participating sports, were collected from medical records. Preoperative CT images were assessed and subcritical bone loss was defined as a bony defect of 13.5%–20% of the healthy glenoid [13]. Intraoperative findings such as complications with bony Bankart lesions, HAGL lesion, SLAP lesion, and the number of anchors for Bankart repair inserted into the glenoid rim were also recorded.
The range of shoulder motion (ROM), the Rowe score, Japan Shoulder Society Shoulder Instability Score (JSS-SIS) [14], and JSS Shoulder Sports Score (JSS-SSS) [15] were assessed before surgery and at the final visit. The ROM include the forward flexion, external rotation (ER) in adduction, internal rotation (IR) behind the back, and the external rotation and internal rotation in 90 degrees shoulder abduction and 90 degrees of elbow flexion (ER in abduction and IR in abduction). The JSS-SIS is a 100-point scoring system based on pain, function, range of motion, radiographic evaluation, and stability. The JSS-SSS is also a 100-point scoring system based on the player's ability, pain, muscle strength, and range of motion. Clinical improvement was also evaluated using minimal clinically important difference (MCID) for the Rowe score, defined as increasing more than 9.7 from the baseline [16]. The final status of RTS, recurrence of instability, and subjective scores such as the Oxford Shoulder Instability Score (OSIS) [17], American Shoulder and Elbow Surgeons (ASES) score [18], and Athletic Shoulder Outcome Scoring System (ASOSS) [19], except for the ROM item, were assessed at the final follow-up via telephone survey. The status of RTS was categorized as follows: (1) complete return: same as or superior to the preinjury level without any shoulder problems; (2) incomplete return to competition: same as preinjury level with any shoulder problems, or inferior to the preinjury level but participated in competitions; (3) unable to return to competition: participated in sports only in practice; and (4) unable to RTS.
Statistical evaluation
All statistical analyses were performed using IBM SPSS software (version 22; IBM, Armonk, NY, USA). A preliminary test for normality was examined using a preliminary Shapiro–Wilk test. The outcomes before and after surgery was compared by Wilcoxon’s signed-rank test or paired t-test. To analyze the factors that influenced the complete RTS, preoperative and intraoperative factors were compared between patients who could achieve complete RTS and those who could not, and Mann–Whitney U test, Student’s t-test, chi-square test, and Fisher’s exact test were used for the comparison. Postoperative outcomes were also compared between the two groups. Postoperative outcomes were compared according to sports type using the Kruskal–Wallis test or one-way ANOVA.