Abstract
The objective of this study was to evaluate the preliminary radiographic and clinical results of grade IV and V acromioclavicular joint disruption repair using the arthroscopic Arthrex acromioclavicular TightRope (Naples, Florida) fixation technique. Numerous procedures have been described for surgical management of acromioclavicular joint disruption. The TightRope device involves an arthroscopic technique that allows nonrigid anatomic fixation of the acromioclavicular joint. A cohort of 10 men and 2 women with a mean age of 43 years (range, 25–61 years) underwent the acromioclavicular joint TightRope procedure between April 2007 and October 2009. Eleven patients had either Rockwood grade IV or V disruptions and 1 sustained a distal third clavicle fracture with acromioclavicular joint disruption. Data was collected from a chart review. Patients were evaluated clinically, radiographically, by the simple shoulder test, and by overall satisfaction. There were 2 failures of reduction and 1 loss of reduction at final radiographic follow-up. The rate of fixation failure was 16.6%. All patients had >110° of total elevation. The majority of patients obtained satisfactory functional results according to the Simple Shoulder Test averaging 11 of 12 questions answered positively (range, 7–12; standard deviation, 1.50) and 11 of 12 patients were satisfied with the procedure. At final phone interview at approximately 2 years postoperatively, 6 patients were lost to follow-up. The remaining patients were all satisfied with the procedure and no patients reported subjective loss of reduction or deterioration of function. Simple Shoulder Test average was maintained with 11 of 12 positively answered questions (range, 7–12; standard deviation, 2.0) This case series revealed a high rate of fixation failure with the TightRope system. Still, most patients were satisfied with the procedure and achieved high functional shoulder results.
Drs Thiel, Mutnal, and Gilot are from the Department of Orthopedic Surgery, Cleveland Clinic Florida, Weston, Florida.
Drs Thiel, Mutnal, and Gilot have no relevant financial relationships to disclose.
This investigation was performed at the Department of Orthopedic Surgery, Cleveland Clinic Florida, Weston, Florida.
Correspondence should be addressed to: Gregory J. Gilot, MD, Department of Orthopedic Surgery, Cleveland Clinic Florida, 2950 Cleveland Clinic Blvd, Weston, FL 33331 (gilotg@ccf.org).Acromioclavicular joint disruption is a common injury about the shoulder, representing 40% to 50% of athletic shoulder injuries. 1,2 Sequelae range from an asymptomatic shoulder to one that is painful with significant loss of strength. Management of acromioclavicular joint disruption is dependent on the grade of injury. Williams et al 3 developed the most widely used classification system after modifying the original system described by Tossy et al. 4,5 The literature supports conservative management of Rockwood type I and II acromioclavicular joint disruption and operative management of type IV, V, and VI injuries. 6 The management of type III injuries, however, remains controversial, with authors advocating both operative and nonoperative treatment. 7–10
Over 60 different procedures have been described for the surgical management of acromioclavicular joint disruption. 11,12 The 4 main surgical options include: (1) primary acromioclavicular joint fixation (with pins, screws, sutures, wires, plates, hook plates) with or without ligament repair or reconstruction; (2) primary coracoclavicular internal fixation (with Bosworth screw, wire, fascia, conjoint tendon, or synthetic sutures) with or without incorporation of acromioclavicular ligament repair/reconstruction 13,14 ; (3) excision of the distal clavicle with or without coracoclavicular ligament repair with fascia or suture, or coracoacromial ligament transfer 12,15,16 ; and (4) dynamic muscle transfers with or without excision of the distal clavicle. 17
The modified Weaver-Dunn reconstruction, which consists of both transfer of the coracoacromial ligament and suture augmentation, is the most commonly performed procedure for acromioclavicular disruption. Multiple studies have shown this technique to be an effective option. 11,18–21 Some authors, however, have noted residual subluxation with this procedure. 22,23 Other reconstructions, as well as the native coracoclavicular ligaments, have been shown to have higher biomechanical strength than the modified Weaver-Dunn technique. 24–26
With no 1 technique serving as the gold standard for surgical management of acromioclavicular joint disruption, the treatment of acromioclavicular disruptions continues to evolve. Several novel procedures have been designed to reconstruct the acromioclavicular joint in an anatomic manner. Anatomic reconstructions attempt to reproduce the coracoclavicular ligaments with either allograft or autograft tissue. Studies have reported improved biomechanical strength with this technique, but no clinical studies report improved outcome. 24,27–29 Arthroscopic techniques involve anatomically reconstructing a disrupted acromioclavicular joint by replacing the coracoclavicular ligaments with sutures. Ideally, the patient’s own coracoclavicular ligaments and periosteal sleeve, including the acromioclavicular joint capsule, will subsequently heal when held in a reduced position. 30–35
We describe our experience using an arthroscopically assisted procedure (TightRope; Arthrex, Naples, Florida) (Figures , ) in the surgical management of 12 patients with grade IV or V acromioclavicular joint disruption.
 | Figure 1:. Arthrex TightRope. |
 | Figure 2:. Schematic of the positioned TightRope. |
Materials and Methods
Between April 2007 and October 2009, 12 patients with acute acromioclavicular joint disruption were managed surgically by the senior author (G.J.G.) at Cleveland Clinic Florida Hospital. A chart review of patient demographic data, mechanism of injury, surgical technique/complications, postoperative range of motion, and postoperative visual analog pain scale was performed. For the purpose of our study, we defined total elevation as 120° with any motion beyond 120° being secondary to scapulothoracic substitution. 36 The patients were examined at 48 hours and 6 and 12 weeks postoperatively. Patients were evaluated during the follow-up period by physical examination, radiographic evaluation, and telephone interview.
Radiographic data consisting coracoclavicular distance measurements were obtained preoperatively and postoperatively at 6, 12, and 24 weeks and 1 year (Table ). In the radiological evaluation, the coracoclavicular distance was measured as the vertical distance between the superior border of the coracoid to the superior edge of the clavicle on standard anteroposterior radiographs (Figures –). This measurement was the least vulnerable projection errors. 37 The radiographic outcome was defined and classified as (1) maintained reduction (when the postoperative coracoclavicular distance remained constant), (2) loss of reduction (when the final coracoclavicular distance was less than half the difference between the preoperative and immediate postoperative coracoclavicular distance), and (3) failure of reduction (when the final coracoclavicular distance was greater than or equal to half the difference between the preoperative and immediate postoperative coracoclavicular distance).
 | Table 1. Patient Demographics |
 | Figure 1:. AP radiograph of a Rockwood IV acromioclavicular joint dislocation. |
 | Figure 3:. Three-month postoperative AP radiograph of the TightRope. Note the calcification in the coracoclavicular interval. |
At a minimum of 6 months from the date of surgery, a follow-up telephone interview was conducted during which patients were asked to express global satisfaction on the procedure by responding either satisfied or not satisfied and were also asked to complete the Simple Shoulder Test questionnaire. This was repeated at a minimum of 16 months postoperatively. The Simple Shoulder Test is a standardized, 12-question patient self-assessment outcome measure instrument used to determine shoulder function (Table ). It provides a practical method for evaluating success of a treatment in terms of the percent of patients gaining (and losing) each function after treatment was instituted. It is valid, reliable, responsive, and has high positive predictive value. 20,38,39 For our study the pre-surgical Simple Shoulder Test score was not calculated. It has been shown, however, that patients with no prior or current history of shoulder problems were able to physically accomplish the questioned tasks and answered yes to >95% of all questions. 39
 | Table 2. Measurements of Coracoclavicular Distance of All 12 cases |
To facilitate outcome assessment, the data from the Simple Shoulder Test was converted to a scoring scale. This has been described by previous authors when comparing shoulder scoring scales rotator cuff repair evaluation. 39 The 12 questions were weighted equally on a 100-point percentage scale, with 100 points representing the best result or 12 positive answers. Seventeen points (2 questions) are related to the effect that pain has on the patient’s shoulder function. The functional range of motion achieved by the shoulder can be awarded a maximum of 33 points (4 questions). Strength characteristics account for 25 points (3 questions), and complex functional activities for the shoulder account for the final 25 points (3 questions).
Final clinical follow-up involved 10 men and 2 women with a mean age of 43 years (range, 25–61 years), who were included in this study (Table ). These 12 patients were followed radiographically for a minimum of 3 months (average, 5.75 months; range, 3–18 months). Clinical follow-up was for a minimum of 6 months (average, 19.4 months; range, 6–36 months). Final telephone interview was for a minimum of 16 months (average 22.8 months; range, 16–31 months). Of the 12 disruptions, 6 were sustained during a sporting activity, 5 in a motor vehicle accident, and 1 following a fall. Nine of the injuries were on the left side and three were on the right side. According to Rockwood classification, 8 (66.6%) patients had type V lesions and 3 (25%) had type IV lesions. One (8.3%) patient sustained a distal third clavicle fracture with disruption of the acromioclavicular joint.
For our surgical technique, we used both general and regional anesthesia. The patient is placed in the beach-chair position. Arthroscopic access to the shoulder is gained through a standard posterior portal approximately 2 cm inferior and medial from the posterolateral corner of the acromion. A diagnostic examination is then performed paying special attention to the articular cartilage, biceps tendon, biceps anchor, and rotator cuff tendons. An anterolateral working portal just above the subscapularis tendon, in the lateral most aspect of the rotator interval, is established using an outside-in technique. A 3-cm sagittal incision is made over the clavicle approximately 3 cm medial to the acromioclavicular joint. The deltotrapezia fascia is incised in the same direction. With the aid of a small periosteal elevator, the superior surface of the clavicle is cleared of soft tissue.
With the 70° scope in the posterior portal, the subcoracoid space is arthroscopically dissected using a radiofrequency ablation device and/or shaver introduced through the anterolateral portal. The goal is to obtain clear visualization of the undersurface of the coracoid arch through which drill holes will be made. The drill entry points were based upon anatomical parameters reported by Rios et al 40 and Salzmann et al. 41 Fluoroscopy is used for correct placement of drill holes during the procedure. An acromioclavicular drill guide and marking hook (Arthrex) is introduced through the anteroinferior portal under direct vision and placed under the medial part of the coracoid arch near its base while its other end (the drill sleeve) is placed over the desired entry point approximately 4.5 cm from the lateral end of the clavicle. With the drill guide held in this position, and the acromioclavicular marking guide clearly visualized arthroscopically, a 2.4-mm guide pin is drilled through the clavicle and the base of the coracoid. The guide is removed while the pin is maintained in its position through the clavicle and coracoid base. The guide pin is then overdrilled with a 4.0-mm cannulated drill bit transclavicular and transcoracoidal. A nitinol suture passer is inserted into the subcoracoid space through the drill. The nitinol wire is retrieved via the anteroinferior portal. The cannulated drill bit is removed. The TightRope is attached to the nitinol suture passer and advanced through the drill hole from superior to inferior until the metal button is flipped beneath the coracoid arch.
Following the same technique, a second TightRope device is placed 2 cm from the lateral end of the clavicle and adjacent to the lateral part of the coracoid arch near its base. For our first 3 patients, only 1 TightRope device was used. An assistant supports the weight of the ipsilateral arm and the surgeon tightens the TightRope devices on the clavicle, thereby reducing the acromioclavicular disruption anatomically. Reduction is assessed with palpation of the acromioclavicular joint. The TightRope devices are knotted securely once satisfactory reduction is achieved. The final construct consists of 2 TightRope devices spanning the coracoclavicular space anatomically reproducing the coracoclavicular ligaments. The clavicular wound is closed in layers and the portals are closed in standard fashion. Postoperatively, the shoulder is protected in a sling for 6 weeks. During that time, only passive range-of-motion exercises are permitted. Shoulder motion and muscle strengthening exercises are delayed up to 10 to 12 weeks.
All statistical analyses were run on Stata 10.0 (Stata Corporation, College Station, Texas).
Results
Patients treated by the TightRope device obtained satisfactory functional results for the shoulder as assessed by the Simple Shoulder Test (Table ). An average of 11 of 12 questions were answered positively (range, 7–12; standard deviations, 1.5 and 2.0 and first and second phone interviews, respectively). The responses were then converted to a 100 point scale, which had an average score of 95 (standard deviation, 12.61). The question receiving the least positive response was “Does your shoulder allow you to sleep comfortably?” with 82% of the patients answering yes. When responding to global satisfaction of the procedure, 11 patients responded that they were satisfied while one patient was unavailable for follow-up telephone interview. At the second interview, approximately 2 years postoperatively, 100% satisfaction was reported from the 6 of 12 patients available for follow-up, with none reporting any subjective loss of reduction.
 | Table 3. Simple Shoulder Test |
At their final office follow-ups, all patients had >110° active forward flexion. With respect to the visual analog pain scale, 8 patients were pain free, 3 patients reported pain of <3/10, and 1 patient reported pain of 8/10 (Table ).
Regarding radiographic assessment of reduction and maintenance of reduction, 2 patients had failure of reduction and 1 patient had loss of reduction (Table ). The 2 patients with failure of reduction both had only one TightRope device placed. Failure of reduction occurred at sometime between the second and 12th postoperative week in both patients. The patient who experienced a loss of reduction had it occur sometime between 6 months and 1 year from surgical date. None of the patients who had a failure or loss of reduction experienced a new injury. They also did not report an acute onset of pain or audible snap. The overall rate of fixation failure was 16.6%.
In 2 patients who had either a failure or loss of reduction, the Simple Shoulder Test score was 100 and final range of motion was 120° of forward flexion. One patient with failure of reduction was not available for follow-up Simple Shoulder Test scoring (Table ).
No postoperative complications related to the procedure were found (Table ). During regular follow-up, we observed no other complications such as osteolysis, cut-through phenomena, fracture non-union, neurovascular injuries, deep infection, or frozen shoulder.
Discussion
The management of acromioclavicular joint disruptions has continued to evolve over the last decade with arthroscopic and tendon-transfer techniques, termed anatomic reconstructions, arising to challenge the standard modified Weaver-Dunn reconstruction. These novel techniques are designed to improve biomechanical strength and to be less invasive. 24,30,35,40,42
Multiple arthroscopic techniques have been described both in the acute and chronic setting. Techniques include: (1) harvesting the native coracoacromial ligament arthroscopically followed by an arthroscopic distal clavicle resection and transfer of the ligament; (2) suture augmentation using bone anchors arthroscopically placed into the base of the coracoid; (3) suture augmentation looped under the coracoid using direct arthroscopic visualization; or, (4) reduction of the clavicle into its anatomic position using the TightRope technique (Arthrex) to recreate the coracoclavicular ligaments. 30,31,33,34
The goal of anatomic reconstruction is to provide a stable and functional construct through reconstruction of the conoid and trapezoid ligaments. 6,18,24,27,29 Biomechanical studies, however, have shown that described anatomic procedures do not restore the strength and stiffness of the native acromioclavicular joint complex. 27,28,43
Walz et al 21 studied the biomechanical properties of the TightRope device. The authors compared cyclic loading and load to failure between native coracoclavicular ligaments and an anatomic reconstruction using 2 TightRope devices in cadavers. The mean vertical force in static load until failure measured 598 N and 982 N for the coracoclavicular ligaments and TightRope model, respectively. The mean anterior force in static load until failure was 338 N in the coracoclavicular ligament model compared to 627 N in the TightRope model. The TightRope model had more repetitions until failure during cyclic loading. The study showed that the TightRope reconstruction technique led to favorable in vitro results with forces greater than or equal to those of the native coracoclavicular ligaments.
Clinical studies on the TightRope device are limited, with only a few case reports and 2 case series available in the literature. 31,44–47 To our knowledge, the largest series to date is by Salzmann et al. 46 In their study, 23 patients with acute acromioclavicular joint disruptions underwent reduction and implantation of 2 TightRope devices. At a mean follow-up of 30 months, significant improvements in the visual analog scale and Constant scores were noted. Postoperative radiographic acromioclavicular joint alignment was unsatisfactory in 8 cases, although the authors noted no difference in clinical outcome compared to the patients who maintained reduction.
In a study by Lim et al, 45 eight patients with an acute acromioclavicular joint injury were managed with implantation of one TightRope device. The patients were followed for a minimum of 6 months. They noted a 50% fixation failure rate, with loss of reduction occurring between the second and sixth postoperative weeks. Retrieved specimens revealed suture abrasion that was postulated to be the mechanism of failure. At final follow-up, 4 of the 8 patients had uneventful recovery with no pain and resumption of full duties.
Despite reportedly having biomechanical properties comparable to the native coracoclavicular ligaments, the TightRope device still had a high fixation failure rate, both in Lim et al’s 45 (50%) and Salzmann et al’s 46 (34%) studies, as well as in our study (16.6%). This is consistent with other available techniques such as the modified-Weaver Dunn, which has been reported to have subluxation or disruption in the chronic setting as high as 30%. 21–23 The 2 failures in our study occurred in patients who had only 1 TightRope device implanted. During the study period, we changed our technique so that 2 TightRope devices were used. We began using 2 TightRope devices because we felt this model was a better anatomic recreation of the coracoclavicular ligaments in accordance with Walz et al’s 21biomechanical study. We also felt that if 1 device should fail then the second device would serve as a back-up to prevent complete fixation failure. The use of only 1 TightRope device may explain the high rate of fixation failure in Lim et al’s 45 study.
The patients in our study reported being satisfied with the procedure and achieved satisfactory functional results of the shoulder, with an average score of 95 on the initial Simple Shoulder Test, including the patients that had failure or loss of reduction. This is consistent with the study findings of other techniques, in which loss of reduction has not been shown to lead to symptoms or reoperation in the majority of patients. 46,48
Despite half of the initial group being unavailable for final telephone interview, the results were consistent with the initial phone interview with 11 of 12 questions answered positively and 6 of 6 patients satisfied with the procedure. The patients available for this final interview were comprised of those who underwent the reconstruction more recently. When asked why they did not return for their last scheduled follow-up, they cited not having any significant problems as the main reason. This response could be extrapolated to the remainder of the initial group. Given that most of the patients from the initial group were local, it could also be assumed that any catastrophic failures would have likely presented to our clinic. Of note, a patient who recently underwent reconstruction who was not in the initial group, reported 12/12 on the Simple Shoulder Test, was satisfied with the procedure at interview 8 months postoperatively and the final radiograph revealing maintenance of reduction.
To date, there is only 1 report in the literature of a complication using the TightRope device for acromioclavicular joint disruptions. The authors reported a clavicle fracture through a drill hole following a repeat trauma 8 months after the index surgery. They suggest removal of the device following healing to prevent a stress riser and potential clavicle fracture. 44 We noted no complication in our study and currently do not advocate removal of the device following healing.
This study has several key limitations, which include the small number of cases, limited clinical and radiographic follow-up, number of patients lost to follow-up at final phone interview, lack of a control group, and possibility of intraobserver error with respect to radiographic measurements.
Conclusion
The proposed advantage of the TightRope device is that it allows for nonrigid anatomic fixation of the acromioclavicular joint, thus maintaining reduction while allowing normal rotation of the clavicle. 45Although clinical studies are limited, our series, as well as those of Lim et al 45 and Salzman et al, 46revealed a high rate of fixation failure with the TightRope system. Despite the high failure rate, the majority of patients in our study reported being satisfied with the procedure and achieved high functional results of the shoulder.
Based on the biomechanical study by Walz et al, 21 we recommend that 2 TightRope devices be implanted. We believe that using 2 devices more closely replicate the function of the native coracoclavicular ligaments. There is a question regarding the long-term stability of the implant. Do the coracoclavicular ligaments, periosteum, and acromioclavicular joint capsule reconstitute themselves with reduction of the clavicle alone? Several of our patients showed evidence of increased radiodensity at the coracoclavicular interval on postoperative films (Figure ). In addition, other authors have noted tissue complexes around the TightRope device at the time of second-look arthroscopy. 21 Additionally, we believe this study warrants further investigation into this method of acromioclavicular joint reconstruction. Adequately powered, multicenter, prospective, randomized, controlled studies with long-term follow-up are needed to better determine the efficacy and role of the TightRope device in the management of acute acromioclavicular joint disruptions.
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