Treatment of Acute Unstable Distal Clavicle Fractures with Single Coracoclavicular Suture Fixation

Materials and Methods

From 2004 to 2006, twenty-nine consecutive patients with acute, closed Neer type IIb distal clavicular fractures were treated operatively at our institution. One patient was lost to follow-up and excluded from the study. Of the remaining 28 patients, 18 were men and 10 were women. Mean patient age was 37.9 years (range, 19–71 years) ().

Table. Patient Data

Mechanisms of injury included motorcycle accidents (n=24) and falls (n=4). Twenty-three patients without associated injuries were treated operatively within 3 days. Five patients with associated injuries, including 2 with rib fractures and 3 with head injuries, underwent surgery within 2 weeks. Two experienced orthopedic trauma surgeons (S.W.Y., L.C.L.) treated all patients with the same technique. A single independent observer (S.W.Y.) evaluated and reviewed the results of all patients.

Surgical Technique

Surgery was performed with the patient under general anesthesia in the semi-seated position. One intravenous dose of cefazolin (1000 mg) was given prophylactically to all patients. A longitudinal skin incision was made approximately 5 cm from the distal clavicle to the coracoid process. The anterior deltoid muscle was detached from the medial segment of the clavicle to access the base of the coracoid process. A right-angle clamp was used to pass the Mersilene tape through the inferior base of the coracoid process and around the medial clavicular segment (Figure ). The fracture site was reduced by elevating the shoulder and pressing the medial fragment of clavicle down until it contacted the lateral fragment in as anatomic a position as possible. The Mersilene tape was tied to maintain reduction of the fracture and to recover the normal coracoclavicular space. No attempt was made to repair the remnants of the torn coracoclavicular ligament.

Figure 1:. Longitudinal Incision from the Distal Clavicle to the Coracoid Process (A). Mersilene Tape Was Passed Around the Base of the Coracoid Process and the Medial Clavicular Fragment. The Node Was Tied Anterior, not Superior, to the Clavicle (arrow) (B).

Postoperatively, pendulum exercises for the affected shoulder were encouraged, and the arm was protected in an arm sling for 4 weeks. Active range-of-motion exercises were then started.

Patients were clinically and radiographically followed up in 6-week intervals until bony union. Bilateral anteroposterior clavicle radiographs in a standing view without stress were taken. Bony union was clinically defined as the patient’s ability to move the shoulder without pain. Bony union was radiographically defined as a solid, bridging callus or as obliteration of the fracture site (Figure ). The coracoclavicular difference was recorded after measurement of the distance between the highest point of the coracoid and the inferior border of the clavicle on both sides according to the radiographs.

Figure 2:. Images Showing a Neer Type II Distal Clavicular Fracture Before (A) and After (B) Single Coracoclavicular Fixation with Mersilene Tape, with Bony Union After Surgery (C).

The functional results were evaluated using the modified University of California Los Angeles (UCLA) shoulder rating scale, which assesses pain (maximum 10 points), function (maximum 10 points), active forward flexion (maximum 5 points), strength of forward flexion (maximum 5 points), and patient satisfaction (maximum 5 points). ^7,16 Based on the UCLA score, the clinical results were stratified as excellent (34–35 points), good (28–33 points), fair (21–27 points), or poor (<21 points).

Results

Mean follow-up was 57.3 months (range, 46–78 months). All fractures healed without secondary procedures. No wound infections, loss of reduction, bone erosion, or postoperative arthrosis of the acromioclavicular joint occurred. Heterotopic ossification in the coracoclavicular space was encountered in 2 patients (7%) with no clinical symptoms. Table summarizes the data for all 28 patients.

Mean union time was 14.3 weeks (range, 12–24 weeks). Mean coracoclavicular difference preoperatively was 20.1 mm (range, 18–27 mm) and at last follow-up was 0.57 mm (range, 0–2 mm). Mean UCLA shoulder rating score was 34 (range, 29–35). Twenty patients had excellent results and 8 had good results. All patients were able to resume their previous levels of activity.

There was no major morbidity, and 2 minor complications occurred. One patient experienced a frozen shoulder on the treated side postoperatively. After adequate rehabilitation, the symptom resolved without complications at final follow-up. Another patient reported uncomfortable skin tenting due to subcutaneous protrusion of the suture node of the Mersilene tape (Figure ). After bony union of the fracture site, simple subcutaneous surgical removal of the node was performed using local anesthesia, and the discomfort resolved.

Figure 3:. Photograph Showing Skin Tenting with Protrusion of a Suture Node (arrow) (A). The Suture Node Should not Be Placed Above the Clavicle (arrow), Where It Can Cause Skin Irritation (B).

Discussion

The clavicle is a common site of traumatic fracture. Most clavicular fractures can be treated successfully with nonsurgical methods. However, Neer type II distal clavicular fractures with a loss of restraint of the coracoclavicular ligament are at high risk for complications, such as non-union or shoulder dysfunction if conservatively treated. ^4,5 Oh et al ⁶ reviewed 425 Neer type II fractures and showed nonsurgical treatment resulted in a nonunion rate of 33.3%; surgical treatment resulted in only a 1.6% nonunion rate. Many methods have been proposed for the treatment these fractures ^2,4,7–17 ; however, the best surgical treatment is still unclear.

Intramedullary K-wire fixation is simple. ² However, many authors do not recommend it because several complications can occur, including pin migration, pin tract infection, and loss of reduction. ^18–20 Transacromial fixation with a threaded Knowles pin is more secure than with a smooth pin, and this method avoids pin migration. ⁸ However, the late complication of acromioclavicular joint arthrosis remains a concern. Scadden and Richards ²¹ reported good results with fixation using an intramedullary Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) malleolar screw that did not interfere with the acromioclavicular joint; however, its use was limited with comminuted or small distal fragments. Wang and Wong ²² reported that extra-articular Knowles pin fixation offered an indirect reduction method for the treatment of unstable distal clavicle fractures without further injury to the acromioclavicular joint. However, radiolucency around the pins in all cases and pin migration in 8 cases (32%) resulted in a second procedure to remove the pin in all cases.

Plate fixation using a clavicular hook plate has been effective in recent years, but a secondary operation to remove the hardware is necessary to prevent subacromial impingement and rotator cuff tears. ^11,23,24 Additionally, plate fixation poses a risk of acromial fracture and hook cut-out in patients with osteoporosis. ^11,25 Locking distal radius plates were also used to treat unstable distal clavicle fractures, but the lateral fragment had to be large enough to accept the T part of the plate. ^13–15 Both the hook plate and the locking plate require wide exposure and devascularization of the clavicle. Coracoclavicular screw fixation involves rigid fixation to manage disruption of the coracoclavicular ligament and also requires a second operation to remove the hardware. ^7,9,12 Furthermore, coracoclavicular screws can loosen in patients with a small coracoid process or osteoporosis and demonstrate failure rate as high as 32%. ^7,22 Adequate fixation is also difficult to achieve with tension band wiring when distal fragments are comminuted. ¹⁰

Oh et al ⁶ cited significantly higher complication rates with the hook plate (40.7%) and the K-wire plus tension band wire (20%) than with coracoclavicular stabilization (4.8%), intramedullary fixation (2.4%), and interfragmentary fixation (6.3%) after a systematic review of 425 unstable distal clavicle fractures.

Shin et al ¹⁷ used suture anchors for coracoclavicular stabilization, which represented a reliable technique for restoring stability. However, clavicular erosion by the suture materials was found in 2 patients (11%). Chen et al ²⁶ reported treating the distal clavicle with a disruption of the coracoclavicular ligament using Mersilene tape, which was similar to our method. However, they repaired the torn coracoclavicular ligament and fixed the fracture segments with a wire. We felt these steps were unnecessary since a solid bony union was expected. Unnecessary procedures may increase the extent of soft tissue stripping and devascularization.

In our series, single coracoclavicular fixation with Mersilene tape was effective in all patients with acute Neer type IIb distal clavicular fractures without any hardware, even in patients with comminuted distal fragments or osteoporosis. Mersilene tape maintained the reduction of the fracture and restored the coracoclavicular space, and it changed the pattern of the fracture from Neer type II to type I. In the Neer classification scheme, type I has intact restraint of the coracoclavicular ligament, and conservative treatment is indicated. Repair of the torn coracoclavicular ligament was unnecessary because the remnants were too small to suture and heal. The Mersilene tape was strong enough to provide restraint until bony union occurred. No hardware needed to be removed with this method, and no damage to the acromioclavicular joint occurred. This procedure may be associated with a risk of clavicle or coracoid erosion, or even fracture of the coracoid tip. ¹⁷ Nevertheless, no such complication occurred in our series during the mean 57.3-month follow-up. Mersilene tape is wider than other suture materials, such as PDS (Ethicon) and FiberWire (Arthrex, Inc, Naples, Florida), which reduces the stress of contact on the bone.

As reported earlier, only 2 minor complications occurred in our 28 patients. Pain and concern about exercising after surgery may have contributed to the frozen shoulder, although it resolved without complications after adequate rehabilitation. Therefore, pendulum exercises with the affected shoulder must be performed as soon as possible after surgery to prevent adhesion of the shoulder joint. The other complication, uncomfortable skin tenting caused by a suture node, was due to a node tied over the clavicle, which resulted in subcutaneous irritation. The node should be tied anteriorly and covered by the deltoid muscle flap to avoid direct irritation of skin (Figure ).

Limitations of our study include the mid-term follow-up and small number of patients (28). In general, the incidence of unstable distal clavicle fractures is low, and large numbers of patients are difficult to obtain. Our study is a large case series compared to the majority of studies found in the literature. However, larger study populations are required to confirm these results. Long-term follow-up may be necessary to assess the incidence of acromioclavicular arthritis and clavicular erosion by the suture materials.

Conclusion

Unstable distal clavicle fractures are associated with high risk of nonunion, and therefore operative treatment is favored. Various surgical methods can be found in the literature, but no gold standard has been established. Based on the results of this series, simple coracoclavicular fixation of acute unstable distal clavicular fractures with Mersilene tape can stabilize a loss of restraint of the coracoclavicular ligament and offer a satisfactory outcome at a mid-term follow-up.