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Arthroscopic Bankart Repair With Knotless Suture Anchor for Traumatic Anterior Shoulder Instability: Results of Short-Term Follow-Up
Arthroscopic Bankart Repair With Knotless Suture Anchor for Traumatic Anterior Shoulder Instability: Results of Short-Term Follow-Up Kenji Hayashida, M.D., Ph.D., Minoru Yoneda, M.D., Ph.D., Naoko Mizuno, M.D., Sunao Fukushima, M.D., and Shigeto Nakagawa, M.D., Ph.D.
Purpose: To assess the clinical results of arthroscopic Bankart repair with the knotless suture anchor for traumatic recurrent anterior shoulder instability. Methods: A total of 47 patients with traumatic recurrent anterior shoulder instability and without severe glenoid bone defect who underwent arthroscopic Bankart repair with knotless suture anchors and were followed-up for longer than 2 years were included in the present study. The average age at surgery was 26 years (range, 16 to 49 years), with an average follow-up period of 28 months (range, 24 to 38 months). Results: Clinical score as evaluated by the modified Rowe score advanced from 31 points to 91 points. In all, 35 patients were scored as excellent and 6 as good; the success rate was 87% (41 of 47), and the recurrence rate was 6.4% (3 of 47). External rotation was reduced by 8° at adduction and by 6° at 90° of abduction. Of 12 patients, 7 (58%) returned completely to collision sports at preinjury levels, and 2 of 12 (17%) returned at a lower level. We experienced anchor-related trouble in 3 cases. One was the backwardness of the anchor at 2 months after operation. Breakage of the anchor loop occurred during the procedures in 2 cases. Conclusions: The clinical results of arthroscopic Bankart repair with knotless suture anchor were favorable; however, some pitfalls, such as the backwardness of the anchor and cutting of the anchor loop, were experienced. When using this anchor, its properties should be well recognized. Level of Evidence: Level IV, therapeutic case series. Key Words: Shoulder—Instability—Arthroscopy—Bankart repair—Knotless suture anchor.
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linical results of arthroscopic Bankart repair are variable.1-10 Although previous reports have shown high recurrence rates, recent studies have reported a recurrence rate of less than 10% and good clinical outcomes that were almost comparable with those following the open Bankart procedure. In particular, the suture anchor method has shown stable
From the Department of Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital (K.H.); Shoulder and Sports Medicine Service, Osaka Koseinenkin Hospital (M.Y., N.M., S.F., S.N.), Hirakata, Osaka, Japan. Address correspondence and reprint requests to Kenji Hayashida, M.D., Ph.D., Department of Orthopedic Surgery, Hoshigaoka Koseinenkin Hospital, Hoshigaoka 4-8-1, Hirakata, Osaka 573-8511, Japan. E-mail: [email protected] © 2006 by the Arthroscopy Association of North America 0749-8063/06/2206-4661$32.00/0 doi:10.1016/j.arthro.2006.03.006
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clinical results,4-8 and this procedure has been widely used for arthroscopic Bankart repair. The most significant advantage of the suture anchor method is that the glenohumeral ligament–labrum complex is directly sutured to an anterior glenoid rim; this procedure should induce good healing between bone and ligament–labrum complex. However, some problems have been noted with this procedure. A good quality of suture anchor repair by arthroscopy is difficult to achieve technically. Satisfactory knot tying requires significant practice with a special knot-tying device, especially when the tension on the suture is high. The knotless suture anchor was developed by Thal,11 who reported the possible advantages of the knotless anchor compared with the traditional suture anchor technique. First, knot tying is not needed. Second, no bulky tied knot remains in the joint. Thal
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 22, No 6 (June), 2006: pp 620-626
BANKART REPAIR IN SHOULDER ARTHROSCOPY also reported that the biomechanical properties of knotless suture anchors and strength of anchor loops were comparable to No. 5 Ethibond and achieved a greater capsular shift than was attained with the simple suture anchor method.11 We agreed with him about the concept of knotless anchors and began using these anchors in September 2000 in arthroscopic Bankart repair provided to patients with traumatic recurrent anterior instability. We obtained favorable clinical results in the present study; however, some troubles were reported in the use of the knotless anchor. Here, we describe our clinical results, the problems we experienced, and recommend techniques to prevent trouble in the use of this anchor.
METHODS From September 2000 to December 2002, 52 shoulders 52 patients with traumatic recurrent anterior shoulder instability were treated by arthroscopic Bankart repair with knotless anchors (DePuy Mitek, Norwood, MA). All patients fulfilled patient criteria for arthroscopic Bankart repair at our institute. These criteria were: (1) Patients experienced traumatic recurrent anterior shoulder instability; (2) the main pathologic lesion of anterior instability was recognized through arthroscopy as a Bankart lesion—not as a humeral side avulsion of the glenohumeral ligament or a midsubstance capsular tear; (3) patients did not have a severe bone defect at the anteroinferior glenoid of greater than 20% of the unaffected side as assessed preoperatively by computed tomography (CT) or magnetic resonance (MR) arthrography. Of 52 patients, 47 were followed-up postoperatively for longer than 2 years and were included in the present study. The other 5 patients were lost to follow-up. Of 47 patients, 38 were male and 9 were female. A total of 30 patients were affected in the right shoulder and 32 patients on the dominant side. Dislocation was experienced by 28 patients, and 19 had subluxation. The average age of patients at surgery was 26 years (range, 16 to 49 years), and the average follow-up period was 28 months (range, 24 to 38 months). In all, 11 patients had experienced dislocation or subluxation between 2 and 4 times, 18 experienced it between 5 and 10 times, and the other 18 more than 10 times. Regarding preoperative sports activity, 17 patients played collision sports at a competitive level, and 12 patients wished to return to the same level of performance.
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Examination Under Anesthesia Translation of the humeral head was examined with the patient under general anesthesia and in the supine position for anterior, posterior, and inferior events in adduction and abduction positions before surgery. In all, 44 shoulders showed greater anterior shift than the nonoperated side in the abduction position. Three shoulders showed the same degree of shift. Eleven shoulders had greater anterior shift in the adduction position, and 6 showed greater inferior shift. A total of 25 shoulders locked over the glenoid in anterior drawer at abduction. Operative Technique Patients were placed in the lateral decubitus position while they were under general anesthesia. The operated arm was pulled by a traction device (Ronci Surgical, Minneapolis, MN) at 3 to 5 kg of weight. We used 3 portals, including posterior, anterosuperior, and anteroinferior, for arthroscopic Bankart repair performed with knotless anchors. After general arthroscopic examination had been performed through the posterior and anterosuperior portals, the arthroscope was placed in the posterior portal, and the view from the posterior portal was primarily used for Bankart repair. The anteroinferior glenohumeral ligament (AIGHL) was mobilized adequately, and the anterior glenoid neck was decorticated by a motorized burr with the use of the anterosuperior and anteroinferior portals. Anchor holes were created on the glenoid surface 1 to 2 mm inside from the glenoid edge at the 1:30, 3, and 4:30 o’clock positions in the right shoulder; 3 anchors (10:30, 9, and 7:30 o’clock positions in a left shoulder) were used through the anteroinferior portal. If 4 anchors were used, drill holes were made at the 1, 2, 3, and 4:30 o’clock positions in a right shoulder; 11, 10, 9, and 7:30 o’clock positions were used in a left shoulder. The knotless anchor holds a soft tissue by the looped anchor loop formed between the anchor body and the anchor tip. Because length of the anchor loop is fixed (30 mm) (Fig 1A), the length of the looped anchor loop from the anchor tail is 8 mm when the anchor loop is caught by the anchor tip (Fig 1B). The anchor was usually inserted 2 to 3 mm deeper to beyond the joint surface; the length of the anchor loop for holding tissue was 5 to 6 mm. We thought proper length of the soft tissue held by the knotless anchor was about 5 mm, and we usually passed the anchor loop at about 5 mm lateral from the medial end of the ligament–labrum complex (Fig 2). We used No. 2 Proline (Ethicon, Somer-
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FIGURE 1. (A) Length of the anchor loop (30 mm) for catching soft tissue. When the anchor loop is caught by the anchor tip (B), the length between the end of the looped anchor loop and the anchor tail is 8 mm (a-b). When the anchor is inserted 3 mm more deeply beyond the joint surface, 5 mm of the looped anchor loop (c-b) remains for catching soft tissue.
ville, NJ) as a shuttle suture. The shuttle suture was passed through the proper AIGHL–labrum complex with the use of a suture punch (Linvatec, Largo, FL) or a suture hook (Linvatec) through the anteroinferior portal. The shuttle suture was passed at about 5 mm lateral from the medial end of the ligament– labrum complex for the reasons mentioned previously, and at 5 to 10 mm lower from the anchor hole for appropriate superior capsular shift. The shuttle suture was retrieved from the anterosuperior portal to prevent tangling of sutures. The utility loop and the anchor loop were passed through the tissue with the use of the shuttle suture. It was very important that the length of the looped anchor loop be adjusted equally for secure fixation. A No. 2 Proline thread (referred to as Larry’s loop) was placed between the anchor and the anchor loop to adjust the anchor loop equally before the anchor was tapped (Fig 3A). The anchor loop was passed through the tissue when the utility loop was pulled and was caught in the channel at the anchor tip (Fig 3B). At this time, the length of the looped anchor loop was often unequal. The anchor was placed lightly into the anchor hole (Fig 3C). Larry’s loop was pulled to adjust the anchor loop equally (Figs 3D and E), and the anchor was tapped to the desired depth to achieve good attachment of the ligament–labrum complex to the glenoid. At this step, we stopped inserting the anchor when the tail of the anchor reached the level of joint surface (Fig 4A). The looped anchor loop was loose at this time. If too much tissue was caught by the anchor loop, the anchor loop became tight, and the anchor could not be inserted deeply enough without cutting the anchor loop. Next, the anchor was inserted 2 to 3 mm deeper, and the anchor loop became tight; however, constriction of the labrum by the anchor loop was not seen (Fig 4B). Then the anchor was inserted about 1 to 2 mm deeper, and the constriction of the labrum was seen (Fig 4C). After the utility loop and Larry’s loop were removed, the inserter rod was
pulled back slightly to open the anchor fins (arcs) to achieve secure anchoring; then, the inserter was removed. When the anchor inserter rod was pulled, the anchor usually came backward slightly (about 1 mm). For this reason, the anchor should be inserted about 1 to 2 mm deeper until constriction of the labrum was observed. We usually used 3 to 4 anchors to repair a Bankart lesion (Fig 5). Postoperative Management Shoulders were immobilized for 2 weeks in a shoulder immobilizer in the internal rotation position. A sling was applied until 6 weeks postoperatively. Passive forward elevation exercises were begun at 2 weeks after surgery, passive external rotation exercise
FIGURE 2. The site at which the suture is passed in the ligament– labrum complex. The shuttle suture was passed by the suture punch at about 5 mm lateral from the medial end of the ligament–labrum complex.
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FIGURE 3. Length of the looped anchor loop is adjusted equally by Larry’s loop. A No. 2 Proline thread (referred to as Larry’s loop) was placed between the anchor and the anchor loop (A). When the anchor loop is passed through the tissue and is caught by the anchor tip, the length of looped anchor loops is often unequal (B). After the anchor tip is placed within the anchor hole (C), Larry’s loop is pulled until the anchor loop becomes equal (D, E). Adjustment of the anchor loop is important for secure fixation.
started at 3 weeks, and muscle strength exercise first occurred at 6 weeks. Unrestricted activities of daily living were allowed at 3 months after the operation, and sports activity was permitted at 6 months after the operation. Evaluation The modified Rowe score12 was used for the clinical evaluation. Recurrence rate, restriction of external rotation, and return to collision sports activity were also assessed. Clinical evaluation was performed in all patients routinely before surgery and at follow-up. RESULTS The Rowe score had improved from 30.8 points before surgery to 91.3 points at follow-up. Scores for
stability and function were improved (from 5.3 to 46.7 and from 10.1 to 28.2, respectively). A total of 35 patients were scored as excellent and 6 as good; the success rate was 87% (41/47). Three patients were scored as fair. One of them was the first patient treated by means of knotless suture anchors at our institute. Through radiographic studies, we found that 1 of the 3 anchors at the 1 o’clock position had been pulled back slightly at 2 months after surgery; we immediately removed the anchor through arthroscopy. The Bankart lesion was repaired well; however, joint cartilage on the humeral head was already damaged by, and the tail of anchor projected into, the glenohumeral joint, which showed degenerative change. The anchor that was removed was not broken, and the anchor loop was not torn. Patients acquired joint stability but they reported stiffness in
FIGURE 4. Step-by-step anchor insertion and adjustment of tension of the anchor loop. In the first step, the anchor is tapped by the hummer until the tail of the anchor reaches the joint surface (A). The anchor loop is still loose at the time. In the second step, the anchor is inserted 2 to 3 mm more deeply (B), and redundancy of the anchor loop disappears. Finally, the anchor is advanced 1 to 2 mm more deeply until constriction of the soft tissue by the anchor loop (arrows) is observed (C).
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K. HAYASHIDA ET AL. study. We made another anchor hole just beside the original anchor hole and completed the repair. Neither infection nor nerve injury was reported in the present study. DISCUSSION
FIGURE 5. Preoperative and postoperative arthroscopic findings. (A) The left shoulder from the posterior portal before Bankart repair is performed. The ligament–labrum complex disappears from the anterior glenoid rim, and the subscapularis tendon is well recognized. (B) Arthroscopic findings after Bankart repair with 3 knotless suture anchors. The ligament–labrum complex is attached and the anterior edge of the glenoid and the bumper of the labrum are formed. Bulky tied knots are not seen in the joint.
the morning and moderate pain of osteoarthritis after episodes of overuse. The other 2 patients experienced mild apprehension at abduction and external rotation positions when playing contact sports. At 16 months after the operation, 2 patients experienced resubluxation; 1 patient had a redislocation 30 months after the operation. These outcomes were scored as poor. MR images at abduction and external rotation taken 6 months after surgery showed that the anterior labrum had been well repaired in case 1 (Fig 6A) and case 2 (Fig 6B). Patients gained shoulder stability and returned to normal daily life activities, including sports activity. Recurrence occurred after major trauma in both cases at 18 months after the operation. One patient with redislocation had acquired normal activities of daily living without apprehension after the operation. She experienced a redislocation while spiking a ball during a volleyball game 30 months after the operation. She did not undergo MR imaging after her operation had been performed, and the repaired condition was obscure. Recurrence was reported in 3 patients, for a recurrence rate of 6.4% (3 of 47). The average restriction of external rotation at follow-up was 8° at adduction (range, 0° to 30°) and 6° at 90° abduction (range, 0° to 20°). Of 12 patients, 7 (58%) returned to collision sports at their preinjury level. Two of 12 (17%) returned to collision sports activity only at a lower level. One patient who experienced resubluxation and 2 patients who felt apprehension while playing collision sports could not play collision sports at follow-up. We experienced an anchor loop cut while inserting an anchor in 2 patients in the early period of this
Clinical outcomes of the present study showed an 87% (41 of 47) success rate and a 6.4% (3 of 47) recurrence rate. Average loss of external rotation was 8° at adduction and 6° at 90° abduction. Clinical results were favorable, even when the average follow-up was short (28 months). In the present study, we excluded patients with a severe bone defect in the anteroinferior glenoid (⬎20% of the contralateral side as assessed by CT or MR arthrography) and treated them with an open Bankart repair augmented by a modified Bristow procedure.14 Burkhart and De Beer5 reported a high recurrence rate of arthroscopic Bankart repair for patients with severe bone defects. Itoi et al.13 reported overload to the ligament in severe glenoid bone defects of at least 21% of the glenoid length after Bankart repair was completed from a biomechanical point of view. When this is considered, elimination of the shoulders with severe bone defect might be one of the reasons why we obtained good clinical outcomes in the present study. We experienced 3 recurrences. Two of these patients acquired good stability of the shoulder and showed good healing through MR imaging at abduction and external rotation 6 months after surgery; they were able to return to sports activity at their preinjury level. They dislocated their shoulders by high-energy trauma again. We think the surgical treatment for the 2 cases could be successful; excessive stress applied to the repair site induced redislocation. One patient dis-
FIGURE 6. MRI findings at abduction in the external rotation position after 6 months of operation for 2 recurrent cases. Findings at abduction in the external rotation position after 6 months of operation showed that the anterior labrum was repaired well in an American football player (A) and a snowboarder (B). White arrows show the repair sites.
BANKART REPAIR IN SHOULDER ARTHROSCOPY located with minor trauma. Regarding this case, healing of the repair site could be incomplete. We experienced several problems in using the knotless anchor. First, the inserted anchor pulled back after the operation, and the tail of the anchor projected into the joint space. Antonogiannakis et al. reported a case of migration of the knotless anchor.15 The dislocated anchor in this case was broken at the anchor fin; however, the anchor removed in our case was not broken and the anchor loop was preserved. Our case involved a different mechanism than was relevant in theirs. We propose 2 reasons for this trouble. First is that the anchor was not inserted deeply enough. Second is that the anchor was not pulled for secure fixation after insertion. According to the manufacturer’s instructions, pulling the Mitek GII anchor back after insertion with a load of about 40 N is recommended to set the anchor and lock the fins within the bone. The knotless anchor has the same fixation system; however, the surgeon is not recommended to pull the inserter rod to open the fin. We did not pull the anchor back after insertion before we experienced anchor backwardness in this case. Zumstein et al.16 reported gap formation between the knotless anchor and the Mitek GII anchor.16 In their study, they pulled the GII anchor to open the fins; however, they did not pull the knotless anchor according to the company’s instructions. The knotless anchor showed greater gap formation when compared with the Mitek GII anchor. When they applied the pulling load under various conditions, the average difference in anchor backwardness between the GII anchor and the knotless anchor was from 1.2 mm to 1.5 mm. On the basis of these results, pulling a rod to fix the fins in bone might produce 1.2 to 1.5 mm of anchor backwardness. Therefore, we believe that the knotless anchor should be inserted deeply enough and should be pulled after insertion like the GII anchor to minimize anchor regression and prevent the projection of the anchor tail into the joint. However, pulling back on the anchor induces looseness of the anchor loop within the knotless anchor. To resolve the problem, we had to insert the knotless anchor a little more deeply (1 to 2 mm) until a constriction of labrum was formed by the anchor loop; then we were able to pull the anchor to obtain secure anchoring without gap formation. We also experienced another problem. We cut the anchor loop in 2 cases in the early period of this study. Because of the fixed length of the anchor loop, its tension was determined according to the site and depth of the anchor loop within the tissue. If too much of the tissue was caught by the anchor loop, the tension of
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the anchor loop became very tight when the anchor was inserted. After these events, we began to bite about 5 mm lateral of the ligament–labrum complex of the anteroinferior glenohumeral ligament, as mentioned earlier, and at no time did we cut the anchor loop. Proper volume of the ligament–labrum complex within the anchor loop allowed ample depth for anchor insertion and prevented cutting of the anchor loop. The present study has several limitations. First, the number of patients included was relatively small (47 patients) and the average follow-up was short (28 months). Second, this was a retrospective cohort study that did not include a control group. Further investigation with appropriate controls and longer follow-up should help to elucidate the usefulness of the knotless anchor. In the present study, we performed Bankart repair with the knotless anchor and achieved favorable clinical results: 87% success rate, 6.4% recurrence rate, 8° at adduction, and 6° at abduction with limited external rotation. However, we also experienced some pitfalls, such as the backwardness of the anchor and cutting of the anchor loop. Before it is selected for use in surgery, the properties of this type of anchor should be further explored and clearly known by the surgeon.
REFERENCES 1. Weiss KS, Savoie FH. Recent advances in arthroscopic repair of traumatic anterior glenohumeral instability. Clin Orthop 2002;400:117-122. 2. Ryu RKN. Arthroscopic approach to traumatic anterior shoulder instability. Arthroscopy 2003;19:94-101. 3. Abrams JS. Innovations in arthroscopic surgery of the shouder: Advances in arthroscopic shoulder stabilization. Arthroscopy 2003;19:106-108. 4. Gartsman GM, Roddey TS, Hammerman SM. Arthroscopic treatment of anterior-inferior glenohumeral instability. J Bone Joint Surg Am 2000;82:991-1003. 5. Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: Significance of the inverted-peer glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy 2000;16:677-694. 6. Kim SH, Ha KI, Kim SH. Bankart repair in traumatic anterior shoulder instability: Open versus arthroscopic technique. Arthroscopy 2002;18:755-763. 7. Kim SH, Ha KI, Cho YB, Ryu BD, Oh I. Arthroscopic anterior stabilization of the shoulder. J Bone Joint Surg Am 2003;85: 1511-1518. 8. Fabbriciani C, Milano G, Demontis A, Fadda S, Ziranu F, Mulas PD. Arthroscopic versus open treatment of Bankart lesion of the shoulder: A prospective randomized study. Arthroscopy 2004;20:456-462. 9. Hayashida K, Yoneda M, Nakagawa S, Okamura K, Fukushima S. Arthroscopic Bankart suture repair for traumatic
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11. 12. 13.
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anterior shoulder instability: Analysis of the causes of a recurrence. Arthroscopy 1998;14:295-301. Kagaya K, Yoneda M, Hayashida K, et al. Modified Caspari technique for traumatic anterior shoulder instability: Comparison of absorbable sutures versus absorbable plus nonabsorbable sutures. Arthroscopy 1999;15:400-407. Thal R. Knotless suture anchor: Arthroscopic Bankart repair without tying knots. Clin Orthop 2001;390:42-51. Rowe CR, Patel D, Southmayd WW. The Bankart procedure. J Bone Joint Surg Am 1978;60:1-16. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anterior stability of the shoulder after
Bankart repair: A cadaveric study. J Bone Joint Surg Am 2000; 82:35-46. 14. Yoneda M, Hayashida K, Wakitani S, Nakagawa S, Fukushima S. Bankart procedure augmented by coracoid transfer for contact athletes with traumatic anterior shoulder instability. Am J Sports Med 1999;27:21-26. 15. Antonogiannakis E, Yiannakopoulos CK, Karliaftis K, Karabalis C. Late disengagement of a knotless anchor. Arthroscopy 2002; 18:1-4. 16. Zumstein M, Jacob HA, Schneeberger AG. In vitro comparison of standard and knotless metal suture anchors. Arthroscopy 2004;20:517-520.
Purpose: To assess the clinical results of arthroscopic Bankart repair with the knotless suture anchor for traumatic recurrent anterior shoulder instability. Methods: A total of 47 patients with traumatic recurrent anterior shoulder instability and without severe glenoid bone defect who underwent arthroscopic Bankart repair with knotless suture anchors and were followed-up for longer than 2 years were included in the present study. The average age at surgery was 26 years (range, 16 to 49 years), with an average follow-up period of 28 months (range, 24 to 38 months). Results: Clinical score as evaluated by the modified Rowe score advanced from 31 points to 91 points. In all, 35 patients were scored as excellent and 6 as good; the success rate was 87% (41 of 47), and the recurrence rate was 6.4% (3 of 47). External rotation was reduced by 8° at adduction and by 6° at 90° of abduction. Of 12 patients, 7 (58%) returned completely to collision sports at preinjury levels, and 2 of 12 (17%) returned at a lower level. We experienced anchor-related trouble in 3 cases. One was the backwardness of the anchor at 2 months after operation. Breakage of the anchor loop occurred during the procedures in 2 cases. Conclusions: The clinical results of arthroscopic Bankart repair with knotless suture anchor were favorable; however, some pitfalls, such as the backwardness of the anchor and cutting of the anchor loop, were experienced. When using this anchor, its properties should be well recognized. Level of Evidence: Level IV, therapeutic case series. Key Words: Shoulder—Instability—Arthroscopy—Bankart repair—Knotless suture anchor.
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linical results of arthroscopic Bankart repair are variable.1-10 Although previous reports have shown high recurrence rates, recent studies have reported a recurrence rate of less than 10% and good clinical outcomes that were almost comparable with those following the open Bankart procedure. In particular, the suture anchor method has shown stable
From the Department of Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital (K.H.); Shoulder and Sports Medicine Service, Osaka Koseinenkin Hospital (M.Y., N.M., S.F., S.N.), Hirakata, Osaka, Japan. Address correspondence and reprint requests to Kenji Hayashida, M.D., Ph.D., Department of Orthopedic Surgery, Hoshigaoka Koseinenkin Hospital, Hoshigaoka 4-8-1, Hirakata, Osaka 573-8511, Japan. E-mail: [email protected] © 2006 by the Arthroscopy Association of North America 0749-8063/06/2206-4661$32.00/0 doi:10.1016/j.arthro.2006.03.006
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clinical results,4-8 and this procedure has been widely used for arthroscopic Bankart repair. The most significant advantage of the suture anchor method is that the glenohumeral ligament–labrum complex is directly sutured to an anterior glenoid rim; this procedure should induce good healing between bone and ligament–labrum complex. However, some problems have been noted with this procedure. A good quality of suture anchor repair by arthroscopy is difficult to achieve technically. Satisfactory knot tying requires significant practice with a special knot-tying device, especially when the tension on the suture is high. The knotless suture anchor was developed by Thal,11 who reported the possible advantages of the knotless anchor compared with the traditional suture anchor technique. First, knot tying is not needed. Second, no bulky tied knot remains in the joint. Thal
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 22, No 6 (June), 2006: pp 620-626
BANKART REPAIR IN SHOULDER ARTHROSCOPY also reported that the biomechanical properties of knotless suture anchors and strength of anchor loops were comparable to No. 5 Ethibond and achieved a greater capsular shift than was attained with the simple suture anchor method.11 We agreed with him about the concept of knotless anchors and began using these anchors in September 2000 in arthroscopic Bankart repair provided to patients with traumatic recurrent anterior instability. We obtained favorable clinical results in the present study; however, some troubles were reported in the use of the knotless anchor. Here, we describe our clinical results, the problems we experienced, and recommend techniques to prevent trouble in the use of this anchor.
METHODS From September 2000 to December 2002, 52 shoulders 52 patients with traumatic recurrent anterior shoulder instability were treated by arthroscopic Bankart repair with knotless anchors (DePuy Mitek, Norwood, MA). All patients fulfilled patient criteria for arthroscopic Bankart repair at our institute. These criteria were: (1) Patients experienced traumatic recurrent anterior shoulder instability; (2) the main pathologic lesion of anterior instability was recognized through arthroscopy as a Bankart lesion—not as a humeral side avulsion of the glenohumeral ligament or a midsubstance capsular tear; (3) patients did not have a severe bone defect at the anteroinferior glenoid of greater than 20% of the unaffected side as assessed preoperatively by computed tomography (CT) or magnetic resonance (MR) arthrography. Of 52 patients, 47 were followed-up postoperatively for longer than 2 years and were included in the present study. The other 5 patients were lost to follow-up. Of 47 patients, 38 were male and 9 were female. A total of 30 patients were affected in the right shoulder and 32 patients on the dominant side. Dislocation was experienced by 28 patients, and 19 had subluxation. The average age of patients at surgery was 26 years (range, 16 to 49 years), and the average follow-up period was 28 months (range, 24 to 38 months). In all, 11 patients had experienced dislocation or subluxation between 2 and 4 times, 18 experienced it between 5 and 10 times, and the other 18 more than 10 times. Regarding preoperative sports activity, 17 patients played collision sports at a competitive level, and 12 patients wished to return to the same level of performance.
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Examination Under Anesthesia Translation of the humeral head was examined with the patient under general anesthesia and in the supine position for anterior, posterior, and inferior events in adduction and abduction positions before surgery. In all, 44 shoulders showed greater anterior shift than the nonoperated side in the abduction position. Three shoulders showed the same degree of shift. Eleven shoulders had greater anterior shift in the adduction position, and 6 showed greater inferior shift. A total of 25 shoulders locked over the glenoid in anterior drawer at abduction. Operative Technique Patients were placed in the lateral decubitus position while they were under general anesthesia. The operated arm was pulled by a traction device (Ronci Surgical, Minneapolis, MN) at 3 to 5 kg of weight. We used 3 portals, including posterior, anterosuperior, and anteroinferior, for arthroscopic Bankart repair performed with knotless anchors. After general arthroscopic examination had been performed through the posterior and anterosuperior portals, the arthroscope was placed in the posterior portal, and the view from the posterior portal was primarily used for Bankart repair. The anteroinferior glenohumeral ligament (AIGHL) was mobilized adequately, and the anterior glenoid neck was decorticated by a motorized burr with the use of the anterosuperior and anteroinferior portals. Anchor holes were created on the glenoid surface 1 to 2 mm inside from the glenoid edge at the 1:30, 3, and 4:30 o’clock positions in the right shoulder; 3 anchors (10:30, 9, and 7:30 o’clock positions in a left shoulder) were used through the anteroinferior portal. If 4 anchors were used, drill holes were made at the 1, 2, 3, and 4:30 o’clock positions in a right shoulder; 11, 10, 9, and 7:30 o’clock positions were used in a left shoulder. The knotless anchor holds a soft tissue by the looped anchor loop formed between the anchor body and the anchor tip. Because length of the anchor loop is fixed (30 mm) (Fig 1A), the length of the looped anchor loop from the anchor tail is 8 mm when the anchor loop is caught by the anchor tip (Fig 1B). The anchor was usually inserted 2 to 3 mm deeper to beyond the joint surface; the length of the anchor loop for holding tissue was 5 to 6 mm. We thought proper length of the soft tissue held by the knotless anchor was about 5 mm, and we usually passed the anchor loop at about 5 mm lateral from the medial end of the ligament–labrum complex (Fig 2). We used No. 2 Proline (Ethicon, Somer-
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FIGURE 1. (A) Length of the anchor loop (30 mm) for catching soft tissue. When the anchor loop is caught by the anchor tip (B), the length between the end of the looped anchor loop and the anchor tail is 8 mm (a-b). When the anchor is inserted 3 mm more deeply beyond the joint surface, 5 mm of the looped anchor loop (c-b) remains for catching soft tissue.
ville, NJ) as a shuttle suture. The shuttle suture was passed through the proper AIGHL–labrum complex with the use of a suture punch (Linvatec, Largo, FL) or a suture hook (Linvatec) through the anteroinferior portal. The shuttle suture was passed at about 5 mm lateral from the medial end of the ligament– labrum complex for the reasons mentioned previously, and at 5 to 10 mm lower from the anchor hole for appropriate superior capsular shift. The shuttle suture was retrieved from the anterosuperior portal to prevent tangling of sutures. The utility loop and the anchor loop were passed through the tissue with the use of the shuttle suture. It was very important that the length of the looped anchor loop be adjusted equally for secure fixation. A No. 2 Proline thread (referred to as Larry’s loop) was placed between the anchor and the anchor loop to adjust the anchor loop equally before the anchor was tapped (Fig 3A). The anchor loop was passed through the tissue when the utility loop was pulled and was caught in the channel at the anchor tip (Fig 3B). At this time, the length of the looped anchor loop was often unequal. The anchor was placed lightly into the anchor hole (Fig 3C). Larry’s loop was pulled to adjust the anchor loop equally (Figs 3D and E), and the anchor was tapped to the desired depth to achieve good attachment of the ligament–labrum complex to the glenoid. At this step, we stopped inserting the anchor when the tail of the anchor reached the level of joint surface (Fig 4A). The looped anchor loop was loose at this time. If too much tissue was caught by the anchor loop, the anchor loop became tight, and the anchor could not be inserted deeply enough without cutting the anchor loop. Next, the anchor was inserted 2 to 3 mm deeper, and the anchor loop became tight; however, constriction of the labrum by the anchor loop was not seen (Fig 4B). Then the anchor was inserted about 1 to 2 mm deeper, and the constriction of the labrum was seen (Fig 4C). After the utility loop and Larry’s loop were removed, the inserter rod was
pulled back slightly to open the anchor fins (arcs) to achieve secure anchoring; then, the inserter was removed. When the anchor inserter rod was pulled, the anchor usually came backward slightly (about 1 mm). For this reason, the anchor should be inserted about 1 to 2 mm deeper until constriction of the labrum was observed. We usually used 3 to 4 anchors to repair a Bankart lesion (Fig 5). Postoperative Management Shoulders were immobilized for 2 weeks in a shoulder immobilizer in the internal rotation position. A sling was applied until 6 weeks postoperatively. Passive forward elevation exercises were begun at 2 weeks after surgery, passive external rotation exercise
FIGURE 2. The site at which the suture is passed in the ligament– labrum complex. The shuttle suture was passed by the suture punch at about 5 mm lateral from the medial end of the ligament–labrum complex.
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FIGURE 3. Length of the looped anchor loop is adjusted equally by Larry’s loop. A No. 2 Proline thread (referred to as Larry’s loop) was placed between the anchor and the anchor loop (A). When the anchor loop is passed through the tissue and is caught by the anchor tip, the length of looped anchor loops is often unequal (B). After the anchor tip is placed within the anchor hole (C), Larry’s loop is pulled until the anchor loop becomes equal (D, E). Adjustment of the anchor loop is important for secure fixation.
started at 3 weeks, and muscle strength exercise first occurred at 6 weeks. Unrestricted activities of daily living were allowed at 3 months after the operation, and sports activity was permitted at 6 months after the operation. Evaluation The modified Rowe score12 was used for the clinical evaluation. Recurrence rate, restriction of external rotation, and return to collision sports activity were also assessed. Clinical evaluation was performed in all patients routinely before surgery and at follow-up. RESULTS The Rowe score had improved from 30.8 points before surgery to 91.3 points at follow-up. Scores for
stability and function were improved (from 5.3 to 46.7 and from 10.1 to 28.2, respectively). A total of 35 patients were scored as excellent and 6 as good; the success rate was 87% (41/47). Three patients were scored as fair. One of them was the first patient treated by means of knotless suture anchors at our institute. Through radiographic studies, we found that 1 of the 3 anchors at the 1 o’clock position had been pulled back slightly at 2 months after surgery; we immediately removed the anchor through arthroscopy. The Bankart lesion was repaired well; however, joint cartilage on the humeral head was already damaged by, and the tail of anchor projected into, the glenohumeral joint, which showed degenerative change. The anchor that was removed was not broken, and the anchor loop was not torn. Patients acquired joint stability but they reported stiffness in
FIGURE 4. Step-by-step anchor insertion and adjustment of tension of the anchor loop. In the first step, the anchor is tapped by the hummer until the tail of the anchor reaches the joint surface (A). The anchor loop is still loose at the time. In the second step, the anchor is inserted 2 to 3 mm more deeply (B), and redundancy of the anchor loop disappears. Finally, the anchor is advanced 1 to 2 mm more deeply until constriction of the soft tissue by the anchor loop (arrows) is observed (C).
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K. HAYASHIDA ET AL. study. We made another anchor hole just beside the original anchor hole and completed the repair. Neither infection nor nerve injury was reported in the present study. DISCUSSION
FIGURE 5. Preoperative and postoperative arthroscopic findings. (A) The left shoulder from the posterior portal before Bankart repair is performed. The ligament–labrum complex disappears from the anterior glenoid rim, and the subscapularis tendon is well recognized. (B) Arthroscopic findings after Bankart repair with 3 knotless suture anchors. The ligament–labrum complex is attached and the anterior edge of the glenoid and the bumper of the labrum are formed. Bulky tied knots are not seen in the joint.
the morning and moderate pain of osteoarthritis after episodes of overuse. The other 2 patients experienced mild apprehension at abduction and external rotation positions when playing contact sports. At 16 months after the operation, 2 patients experienced resubluxation; 1 patient had a redislocation 30 months after the operation. These outcomes were scored as poor. MR images at abduction and external rotation taken 6 months after surgery showed that the anterior labrum had been well repaired in case 1 (Fig 6A) and case 2 (Fig 6B). Patients gained shoulder stability and returned to normal daily life activities, including sports activity. Recurrence occurred after major trauma in both cases at 18 months after the operation. One patient with redislocation had acquired normal activities of daily living without apprehension after the operation. She experienced a redislocation while spiking a ball during a volleyball game 30 months after the operation. She did not undergo MR imaging after her operation had been performed, and the repaired condition was obscure. Recurrence was reported in 3 patients, for a recurrence rate of 6.4% (3 of 47). The average restriction of external rotation at follow-up was 8° at adduction (range, 0° to 30°) and 6° at 90° abduction (range, 0° to 20°). Of 12 patients, 7 (58%) returned to collision sports at their preinjury level. Two of 12 (17%) returned to collision sports activity only at a lower level. One patient who experienced resubluxation and 2 patients who felt apprehension while playing collision sports could not play collision sports at follow-up. We experienced an anchor loop cut while inserting an anchor in 2 patients in the early period of this
Clinical outcomes of the present study showed an 87% (41 of 47) success rate and a 6.4% (3 of 47) recurrence rate. Average loss of external rotation was 8° at adduction and 6° at 90° abduction. Clinical results were favorable, even when the average follow-up was short (28 months). In the present study, we excluded patients with a severe bone defect in the anteroinferior glenoid (⬎20% of the contralateral side as assessed by CT or MR arthrography) and treated them with an open Bankart repair augmented by a modified Bristow procedure.14 Burkhart and De Beer5 reported a high recurrence rate of arthroscopic Bankart repair for patients with severe bone defects. Itoi et al.13 reported overload to the ligament in severe glenoid bone defects of at least 21% of the glenoid length after Bankart repair was completed from a biomechanical point of view. When this is considered, elimination of the shoulders with severe bone defect might be one of the reasons why we obtained good clinical outcomes in the present study. We experienced 3 recurrences. Two of these patients acquired good stability of the shoulder and showed good healing through MR imaging at abduction and external rotation 6 months after surgery; they were able to return to sports activity at their preinjury level. They dislocated their shoulders by high-energy trauma again. We think the surgical treatment for the 2 cases could be successful; excessive stress applied to the repair site induced redislocation. One patient dis-
FIGURE 6. MRI findings at abduction in the external rotation position after 6 months of operation for 2 recurrent cases. Findings at abduction in the external rotation position after 6 months of operation showed that the anterior labrum was repaired well in an American football player (A) and a snowboarder (B). White arrows show the repair sites.
BANKART REPAIR IN SHOULDER ARTHROSCOPY located with minor trauma. Regarding this case, healing of the repair site could be incomplete. We experienced several problems in using the knotless anchor. First, the inserted anchor pulled back after the operation, and the tail of the anchor projected into the joint space. Antonogiannakis et al. reported a case of migration of the knotless anchor.15 The dislocated anchor in this case was broken at the anchor fin; however, the anchor removed in our case was not broken and the anchor loop was preserved. Our case involved a different mechanism than was relevant in theirs. We propose 2 reasons for this trouble. First is that the anchor was not inserted deeply enough. Second is that the anchor was not pulled for secure fixation after insertion. According to the manufacturer’s instructions, pulling the Mitek GII anchor back after insertion with a load of about 40 N is recommended to set the anchor and lock the fins within the bone. The knotless anchor has the same fixation system; however, the surgeon is not recommended to pull the inserter rod to open the fin. We did not pull the anchor back after insertion before we experienced anchor backwardness in this case. Zumstein et al.16 reported gap formation between the knotless anchor and the Mitek GII anchor.16 In their study, they pulled the GII anchor to open the fins; however, they did not pull the knotless anchor according to the company’s instructions. The knotless anchor showed greater gap formation when compared with the Mitek GII anchor. When they applied the pulling load under various conditions, the average difference in anchor backwardness between the GII anchor and the knotless anchor was from 1.2 mm to 1.5 mm. On the basis of these results, pulling a rod to fix the fins in bone might produce 1.2 to 1.5 mm of anchor backwardness. Therefore, we believe that the knotless anchor should be inserted deeply enough and should be pulled after insertion like the GII anchor to minimize anchor regression and prevent the projection of the anchor tail into the joint. However, pulling back on the anchor induces looseness of the anchor loop within the knotless anchor. To resolve the problem, we had to insert the knotless anchor a little more deeply (1 to 2 mm) until a constriction of labrum was formed by the anchor loop; then we were able to pull the anchor to obtain secure anchoring without gap formation. We also experienced another problem. We cut the anchor loop in 2 cases in the early period of this study. Because of the fixed length of the anchor loop, its tension was determined according to the site and depth of the anchor loop within the tissue. If too much of the tissue was caught by the anchor loop, the tension of
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the anchor loop became very tight when the anchor was inserted. After these events, we began to bite about 5 mm lateral of the ligament–labrum complex of the anteroinferior glenohumeral ligament, as mentioned earlier, and at no time did we cut the anchor loop. Proper volume of the ligament–labrum complex within the anchor loop allowed ample depth for anchor insertion and prevented cutting of the anchor loop. The present study has several limitations. First, the number of patients included was relatively small (47 patients) and the average follow-up was short (28 months). Second, this was a retrospective cohort study that did not include a control group. Further investigation with appropriate controls and longer follow-up should help to elucidate the usefulness of the knotless anchor. In the present study, we performed Bankart repair with the knotless anchor and achieved favorable clinical results: 87% success rate, 6.4% recurrence rate, 8° at adduction, and 6° at abduction with limited external rotation. However, we also experienced some pitfalls, such as the backwardness of the anchor and cutting of the anchor loop. Before it is selected for use in surgery, the properties of this type of anchor should be further explored and clearly known by the surgeon.
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anterior shoulder instability: Analysis of the causes of a recurrence. Arthroscopy 1998;14:295-301. Kagaya K, Yoneda M, Hayashida K, et al. Modified Caspari technique for traumatic anterior shoulder instability: Comparison of absorbable sutures versus absorbable plus nonabsorbable sutures. Arthroscopy 1999;15:400-407. Thal R. Knotless suture anchor: Arthroscopic Bankart repair without tying knots. Clin Orthop 2001;390:42-51. Rowe CR, Patel D, Southmayd WW. The Bankart procedure. J Bone Joint Surg Am 1978;60:1-16. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anterior stability of the shoulder after
Bankart repair: A cadaveric study. J Bone Joint Surg Am 2000; 82:35-46. 14. Yoneda M, Hayashida K, Wakitani S, Nakagawa S, Fukushima S. Bankart procedure augmented by coracoid transfer for contact athletes with traumatic anterior shoulder instability. Am J Sports Med 1999;27:21-26. 15. Antonogiannakis E, Yiannakopoulos CK, Karliaftis K, Karabalis C. Late disengagement of a knotless anchor. Arthroscopy 2002; 18:1-4. 16. Zumstein M, Jacob HA, Schneeberger AG. In vitro comparison of standard and knotless metal suture anchors. Arthroscopy 2004;20:517-520.