The aim of surgical treatment for anterior posttraumatic. Arthroscopic Treatment of Anterior Shoulder Instability Using Knotless Suture Anchors

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1 Arthroscopic Treatment of Anterior Shoulder Instability Using Knotless Suture Anchors Raffaele Garofalo, M.D., Andrea Mocci, M.D., Biagio Moretti, M.D., Eugenio Callari, M.D., Giovanni Di Giacomo, M.D., Nicolas Theumann, M.D., Alec Cikes, M.D., and Elyazid Mouhsine, M.D. Purpose: In this study, we evaluated the results of arthroscopic stabilization of the shoulder using knotless anchors and the lesions associated with anterior-inferior labrum avulsion. Type of Study: Retrospective clinical study. Methods: Twenty consecutive patients affected with anterior unidirectional post-traumatic shoulder instability were treated with arthroscopic reconstruction using knotless anchors. During the surgical procedure, associated lesions such as superior labrum anterior posterior (SLAP) (15%) and rotator interval (15%) were repaired. The patients were evaluated at a mean follow-up of 43 months. Results: Eighty percent of patients resumed sports activity without any limitation and 90% of patients were satisfied with the results of surgery. One patient (5%) had a recurrent dislocation; this patient resumed a contact sport activity despite medical advice. One patient (5%) related signs of shoulder insecurity at the extreme degree of abduction and external rotation; this patient had resumed sports activity with a moderate limitation and was the only patient who was not completely satisfied with the results of surgery. No significant difference was observed between the operated and the contralateral shoulder according to the Rowe and Constant scores. The mean loss of external rotation was 3. We did not have any cases of anchor loosening, nor did we find signs of shoulder degenerative osteoarthritis on the radiographs. Conclusions: The knotless anchor seems to be a viable alternative for arthroscopic labrum repair, allowing a good capsular shift. Arthroscopic management of shoulder instability allows us to diagnose and treat associated lesions, thus improving the success rate of this type of surgery. Level of Evidence: Level IV, case series. Key Words: Bankart Shoulder instability Suture anchor Knotless. The aim of surgical treatment for anterior posttraumatic shoulder instability is to achieve stability without loss of mobility or strength. 1-3 The difficulty in recovering strength, range of motion (particularly in external rotation), and in return to athletic activities after a Bankart procedure 2,4,5 has led to the development of arthroscopic repair techniques. From the Department of Orthopaedics and Traumatology, University Hospital of Lausanne (R.G., N.T., A.C., E.M.), Lausanne, Switzerland; Department of Orthopaedics and Traumatology, the University of Bari (A.M., B.M., E.C.), Bari, Italy; and the Orthopaedic Shoulder Unit, Concordia Hospital (G.D.G.), Rome, Italy. Address correspondence and reprint requests to Elyazid Mouhsine, M.D., OTR-BH 14, CHUV 1011 Lausanne, Switzerland. Elyazid.Mouhsine@hospvd.ch 2005 by the Arthroscopy Association of North America /05/ $30.00/0 doi: /j.arthro Various techniques of arthroscopic stabilization have been developed, such as staples, 6 transglenoid sutures, 6-11 absorbable tacks, 12 and anchor sutures. 11,13-15 The reported recurrence rate after arthroscopic treatment is twice as high as after open surgery. 16 More technical complications and anatomic limitations have been reported with arthroscopic stabilization. 9,13,17-20 A recent study 21 showed that arthroscopic management of anterior-inferior shoulder instability allows the surgeon to recognize and to treat associated lesions with avulsion of the anterior-inferior labrum, thus improving the results of surgery. Suture anchors were developed to allow the same method of fixation as in the open repair technique. On the other hand, the difficulty and the high learning curve necessary to perform satisfactory arthroscopic knot-tying is well recognized. 22 The knotless suture Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 21, No 11 (November), 2005: pp

2 1284 R. GAROFALO ET AL. anchor is a metallic suture anchor (Mitek, Westwood, MA) 10.8 mm long, with a span arc of 7.5 mm, which was proposed to avoid the need for arthroscopic knot tying. 23 The purpose of our study was to evaluate the outcomes of an arthroscopic shoulder stabilization using the knotless suture anchor in a consecutive series of active patients who had post-traumatic anterior shoulder instability, and the lesions associated with anterior-inferior labrum avulsion. METHODS From October 1999 to April 2000, 20 consecutive patients (20 shoulders) presenting with post-traumatic anterior instability were operated on in the Orthopedic Department of the University of Bari, using an arthroscopic stabilization technique with knotless anchor sutures. The patients were the only ones requiring treatment for anterior shoulder instability in the above mentioned period. The same senior surgeon performed the surgical procedure. The patients included 17 men and 3 women, with an average age of 23.2 years (range, 24 to 34 years). There were 13 right shoulders and 7 left shoulders. In 12 cases, the dominant arm was affected. The patients were evaluated at a mean follow-up of 43 months (range, 36 to 48 months). All patients had experienced a traumatic event that caused their shoulder dislocation. Fifteen patients sustained a sports-related injury and the remaining 5 patients were involved in an accident; 4 of these occurred at work and 1 patient was in a motor vehicle accident. There were 16 cases of indirect trauma, and 4 cases of direct trauma. The medical history showed that there was at least 1 case in which a reduction in a hospital setting was necessary. In 14 cases (70%), general anesthesia was necessary. In none of these cases was anesthesia used because the patients were not collaborating because of the pain. In the other 5 cases, anesthesia was used after an unsuccessful attempt of closed reduction. Before surgery, the mean number of instability episodes (dislocation or subluxation) was 6 (range, 3 to 13). All patients reported a failure of their rehabilitation program for at least 6 weeks. No patient had undergone prior surgery for shoulder dislocation. The patients participated in sports activities at various levels, but their performance was limited by shoulder instability. All the patients were evaluated preoperatively by the same orthopaedic shoulder team member. In all TABLE 1. the cases, there were positive apprehension test (with the arm in abduction and external rotation) and relocation test results. In 1 case, a sulcus sign with no other associated signs of multidirectional instability was found. In 5 cases, signs of SLAP lesion were observed. The mean interval between the initial trauma and the surgical procedure was 26 months (range, 8 to 40 months). Preoperative radiographs in anteroposterior, axillary, West Point, and Stryker notch views were taken. Hill-Sachs lesions were revealed in 13 patients. No signs of degenerative arthritis, glenoid dysplasia, or bony Bankart lesions were observed. In this series of patients, magnetic resonance imaging was not routinely performed. Patient data are summarized in Table 1. Surgical Procedure Patient Data No. of shoulders/patients 20/20 Age (yr) 23.2 (range, 18-34) Sex (M/F) 17/3 Dominant arm 12 Dislocation 20 Time between instability and surgery (mo) 26 (range, 8-40) No. of dislocations before surgery 6 (range, 3-13) First trauma Sport 15 (75%) Working accident 4 (20%) Road accident 1 (5%) Sport activity Twice a week 12 (60%) Once a week 6 (30%) Occasionally 2 (10%) Follow-up (mo) 43 (range, 36-48) Under general anesthesia, the shoulder was examined, searching for anterior, posterior, and inferior instability using Altchek grading. 24 The load and shift test with the arm between 70 and 90 was used to describe and quantify the level of anterior instability. The operative report revealed a 2 or 3 anterior translation in all shoulders. In 2 cases, a sulcus sign in adduction external rotation was found between 1 and 2. The procedure was performed in the lateral position. The arm was positioned between 30 and 45 of abduction and 15 of anterior flexion. Traction of 3 to 4 kg was applied to the patient. Three arthroscopic portals according to Wolf 11 were used: posterior, anterior-superior, and anterior-inferior. The procedure started with a diagnostic arthroscopy to evaluate

3 KNOTLESS SUTURE ANCHOR 1285 TABLE 2. Arthroscopic Findings Bankart lesion 17 (85%) ALPSA 3 (15%) Bony Bankart 0 Non-Bankart instability (minor labral lesion) 0 Hill-Sachs nonengaging 13 (65%) Hill-Sachs engaging 0 SLAP lesion type I 1 (5%) SLAP lesion type II 2 (10%) Bicipital partial lesion 0 HAGL 0 Rotator interval lesion 3 (15%) Rotator cuff lesion 0 Loose bodies 4 (20%) Abbreviations: ALPSA, anterior labral periosteal steeve avulsion; HAGL,. shoulder lesions. The arthroscopic findings are summarized in Table 2. In our series, 3 ALPSA lesions (anterior labral periosteal sleeve avulsion) and 17 Bankart lesions (avulsion of anterior-inferior labrum) were reported as principal lesions. In 8 cases, a plication of the inferior glenohumeral ligament complex (considered to be redundant) was carried out. To perform these plications, the arthroscope was inserted in the anterior-superior portal and 2 cannulas were inserted in anterior-inferior and posterosuperior portals. The inferior capsule was visualized and 2 or 3 horizontal mattress stitches with a No. 2 Ethibond suture (Ethicon, Somerville, NJ) were made, taking the capsule and the labrum after abrasion of both surfaces with a synovial rasp. The capsule was thus advanced to the labrum. We believe that this is a critical step because it retains the ligament and reduces the joint volume. In 8 patients, 2 knotless anchors were inserted, 1 at 3 o clock and 1 at 5 o clock (in a right shoulder). In the remaining 12 patients, 3 knotless anchors were used, at 1, 3, and 5 o clock (in a right shoulder) to put the anterior ligamentous complex under tension. Anchors were inserted at 30 with respect to the glenoid surface. Some difficulties were encountered reaching through the anterior-inferior standard portal, a position below 4 o clock to place the anchor. The anchors have always been positioned in a superior position with respect to the capsule to obtain a south north capsular translation and to achieve a good tension of the capsular tissue itself. After treatment of the principal lesion, the associated lesions were addressed; 3 SLAP and 3 rotator interval repairs were performed. The type I SLAP lesion was debrided and the type II was repaired using a mini-revo anchor suture (Linvatec, Largo, FL). A lesion of the rotator interval was retained in the cases when, after a Bankart reconstruction and/or a capsular tensioning, the shoulder showed a persistent inferior or inferior-posterior translation. Arthroscopic findings concerning the rotator interval included lesions such as redundancy of the capsule between the subscapularis and supraspinatus tendon, fraying of the superior border of the subscapularis tendon, and tearing of the superior glenohumeral ligament. 25 After surgery, a standard postoperative rehabilitation protocol was followed (Table 3). Follow-up Evaluation At follow-up, all patients were evaluated by means of a questionnaire that addressed the degree of satisfaction, the return to sports activity and level of participation, the presence of symptoms of instability and discomfort, and recurrence of dislocation or subluxation after surgery. A clinical examination to evaluate motion of shoulder in flexion, abduction, and internal and external rotation at 90 of abduction was carried TABLE 3. Postoperative Rehabilitation Protocol 0-4 weeks Immobilization with sling in internal rotation and 20 of abduction. Handle pump, elbow flexion-extension exercises. Pendulum shoulder exercises. 5-8 weeks Active-assisted and passive shoulder range of motion. External rotation limited to 45. When it is obtained, 120 of active forward flexion, starting rotator cuff strengthening, begin isometric, eccentric, and isotonic, with arm at lowabduction angles weeks Muscle strengthening with weight using gradually increasing load. External rotation limited to 60. Slowly increase abduction during strengthening of deltoid and rotator cuff muscles. Scapular rotator strengthening weeks Auto-stretching exercises to restore complete range of motion. Plyometric exercises. Starting sport-specific exercise (after isocinetic test shows 70% of strength recovered) weeks Orient for return to sport. Sport-related muscular strengthening. Return to sport activity when abduction and external rotation strength are symmetrical. 24 weeks Return to full contact sport.

4 1286 R. GAROFALO ET AL. Parameters TABLE 4. Follow-up Results Operated Shoulder out; the shoulder rating scale of Rowe 3 and the Constant score 26 were calculated. The visual analog scale (VAS) was used to assess pain. The patients were evaluated by an author who did not take part in the surgical procedure and examined the patients for the first time without knowledge of the new material used. Statistical analysis was carried out using measures assessed with nonparametric Wilcox test with a 2-tailed 0.05 level of significance. A radiographic control was performed with anteroposterior and Neer views to evaluate the position of to assess joint position. RESULTS Controlateral Shoulder No. of patients evaluated 20 Recurrence of dislocation 1 (5%) Sensation of insecurity in maximal external rotation 1 (5%) Reoperation 0 Rowe scale (points) 93 (range, ) 96 (range, ) Constant score (points) 92 (range, ) 94 (range, ) Deficit of motion in abduction and external rotation 3 (range, 0-8 ) Resumed working activity (unvaried) 20 (100%) Resumed sport activity No limit 16 (80%) Minimally limited 3 (15%) Moderately limited 1 (5%) Severely limited 0 Follow-up patient data are summarized in Table 4. There were no intraoperative or immediate postoperative complications. One patient (5%) reported an episode of traumatic dislocation of the shoulder in the postoperative period; he sustained a fall while playing soccer 6 months postoperatively. He returned to work with no limitation, but he resumed his sports activity at a lower level than before the initial injury. At follow-up, he referred to a sensation of discomfort. Clinically, the apprehension test was positive. No signs of anchor loosening were observed on the radiographs. However, the patient reported a subjective improvement sensation of the shoulder compared to before surgery, and he refused another surgical procedure. Another patient (5%) reported a sensation of discomfort when his shoulder was placed in abduction and external rotation. Clinically, the apprehension test was negative. In this case, the sports activity (soccer) was resumed with a moderate limitation. This patient reported 13 episodes of dislocation preoperatively, and during his surgical procedure, a narrowing of the rotator interval was performed. In this case, the patient noted some amelioration and no further surgical treatment was performed. One case of transient brachial plexus lesion due to stretching was reported. It was solved without any treatment within 4 weeks from the surgery. No case of superficial or deep infection was noted. Sixteen patients (80%) resumed their previous sports activity level. Three patients (15%) reported a minimal limitation and the patient (5%) discussed above reported a moderate limitation. Three patients (15%) reported occasional pain (VAS, 1-2 / 10) during physical activity, but no patient complained of pain at rest. In our series, all patients resumed their professional activity without any limitation. Comparison of Constant scores did not show any significant differences between the operated and contralateral shoulder (P.15). The analysis according to the Rowe score (function, pain, stability, and range of motion) showed similar mean values with no significant differences (P.09) The mean loss of external rotation was 3 degrees (0 to 8 ) compared with the contralateral shoulder with the arm against the body and the elbow flexed at 90. The radiographic evaluation showed no loosening or disengaging of anchors. The position of anchors was searched on the anteroposterior views and, in particular, the anchor in the lower position was evaluated. Thirteen anchors were found in a 4 o clock position and 7 anchors in a 3:30 position (Fig 1). This confirmed the intraoperative difficulties in reaching a position below 4 o clock with the standard anteriorinferior portal. No signs of glenohumeral degenerative arthritis were found (Fig 1). DISCUSSION In this study, arthroscopic stabilization using a knotless suture anchor restored stability of the shoulder in 18 (90%) of the 20 patients who presented with an anterior unidirectional traumatic instability. The knowledge of the pathologic anatomy of the lesions is the mainstay to obtaining a good surgical outcome in case of shoulder instability. In fact, a simple reattach-

5 KNOTLESS SUTURE ANCHOR 1287 FIGURE 1. (A) Anteroposterior and (B) Neer view radiographs 42 months postoperatively in a 28-year-old man, showing the anchors in place. The lower anchor is in the 3:30 o clock position. No signs of degenerative arthritis are present. ment of the labrum is not sufficient to stabilize the joint; a well-done treatment of the lax ligamentous complex is necessary as well. 11,27 A capsular tension with a south north shift 27 and a plication to reduce the joint volume seems to be very important to achieve good results. Moreover, a well-conducted arthroscopic diagnosis of associated lesions, such as rotator interval or SLAP, 21,25 is very important; if these lesions are found during the surgical procedure, they should be treated so as to improve the long-term outcome. 21 Many authors think that arthroscopic treatment is indicated after the first recurrence of instability. 28 Others have proposed arthroscopic treatment for patients who do not participate in contact sports, 19,29 the procedure being performed in a selected category of athletes. 9,30 Recent studies have shown good results with arthroscopic treatment, but the ratio of recurrence reported after arthroscopic suture knots was between 10% and 20%. 31,32 The difficulty in tying arthroscopic knots has been reported as a possible cause of failure. 22,33 Knotless anchor sutures were developed to avoid the necessity of tying arthroscopic knots. 34 The anchor seems to allow a direct low-profile suture, a good capsular shift, 35 and good bone pullout strength. 34 In our series, 90% of patients were satisfied with the results of surgery and 80% resumed their sports activity at their preinjury level. Twenty percent complained of some discomfort during sports activity. Only 1 patient (5%) reported moderate discomfort during sports activity. This patient presented the highest preoperative dislocation rate. These data are similar to other reports in which arthroscopic 36 or open surgery 30 were performed; the only difference is that in our series there were no elite athletes who returned to contact sports. Our series did include 2 elite noncontact-sport athletes, a swimmer and a tennis player. On evaluation of our series, 13 patients (65%) resumed amateur contact-sports activity, such as soccer, and among these patients, 10 (50%) returned at their preinjury level of activity. One patient reported a subjective sensation of shoulder insecurity and the same patient referred to a moderate discomfort during sports activity. Our percentage is lower compared with other studies, in which similar cases were described. In the operative protocol, the latter patient had a2 sulcus, and he was 1 of 2 patients in whom the rotator interval was narrowed. The result may be explained by the failure to perform a narrowing of the rotator interval, or a difficulty to obtain a good tensioning of the ligamentous complex in a patient who sustained many episodes of dislocation. There was only 1 case (5%) of traumatic dislocation recurrence; this patient returned to contact sports before the end of the suggested period of rehabilitation. Our failure percentage is good compared with those reported in series with open 17,37,38 or arthroscopic procedures. 16,27,35 In terms of range of motion, and in particular concerning the limitation of external rotation, our results are similar to those reported by Thal, 35 although better when compared with other arthroscopic 18 or open surgery series. 17,30,31,37,38 An important point is the difficulty encountered in placing the anchor below the 4 o clock position on the glenoid rim. Our results showed that in no case was the surgeon able to place the lower anchor below the 4 o clock position. This was also found in other studies 39,40 in which, to avoid this problem, an anteriorinferior portal at the 5 o clock position was proposed. At this moment, we do not have any experience with this inferior portal. Nevertheless, the anchors usually allow placement a little bit superior to the 5 o clock position because of the fact that the sutures may be passed through more inferior tissues (south-north translation), thus allowing to compensate the more superior placement of the fixation device. 40 Unlike other series 41 in which the knotless anchors were used, no cases of disengagement of anchors were found. A strong point of our study is that all patients were operated on consecutively by 1 surgeon and were evaluated at follow-up by an independent reviewer. A potential limitation of our study is the short follow-up period. Our patients were reviewed after a minimum follow-up of 3 years. Final results may take more time to be assessed. A literature analysis showed that, for patients treated with su-

6 1288 R. GAROFALO ET AL. ture knot tying anchors, the failure rate at 3 years is 7%, whereas it increases to 30% at 5 years. 19 We believe that this failure rate was related to the knot-tying procedure and not to anchor loosening. If so, it is doubtful that our failure rate would be increased with time. CONCLUSION Arthroscopic treatment using knotless suture anchors appears to be a viable alternative to traditional suture anchors to treat patients with recurrent anterior shoulder instability. Regardless of the means of fixation used, to achieve a successful surgical procedure, a complete analysis and identification of associated lesions is very important. Deformed capsular tissue and/or ligamentous complex, rotator interval, and SLAP lesions, should be assessed during the procedure to improve the surgical outcome. REFERENCES 1. Gill TJ, Micheli LJ, Gebhard F, Binder C. Bankart repair of anterior instability of the shoulder. Long term outcome. 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