Arthroscopic fixation of the clavicle shaft fracture

Abstract

This article describes an arthroscopic technique for the fixation of clavicle shaft fractures. A viewing portal is made 2 cm anterior to the fracture site, and a working portal is made 2 cm lateral to the fracture site. The guide wire for a 4.0-mm cannulated screw is inserted through the fracture site to the medial fracture fragment under arthroscopic guidance. Through the medial fragment, the guide wire is delivered through the skin anteriorly. The fracture is reduced, and then, the guide wire is drilled back across the fracture site to the lateral fracture fragment. After confirming the reduction under arthroscopy, the appropriately sized cannulated screw is inserted after reaming. This arthroscopic technique would be useful for the precise reduction and minimal invasive fixation of clavicle shaft fractures. Preliminary results are encouraging, and further studies with long-term follow-up are needed to determine the precise indications and limitations of the procedure.

Introduction

Midshaft fractures of the clavicle account for 2.6–10% of all adult fractures. ^1,2 Recent prospective studies focusing on the nonoperative treatment of displaced midshaft fractures in the adult population described nonunion rates of 15–20%, objective shoulder muscle strength loss of 18–33%, poor early functioning of the injured shoulder, and up to 42% of patients with residual sequela at 6 months after injury. ^{3 –5} Because of the increasing recognition of suboptimal outcomes following nonoperative treatment, primary operative fixation has become increasingly popular for these injuries.

Operative implants and techniques vary and include intramedullary osteosynthesis and plate fixation. ^{6 –8} Various open methods of fixation have been proposed. For standard open reduction, a transverse skin incision is made over the fracture site, and an extraperiosteal dissection is carried out down to the fracture site. Several complications, such as breakage or loosening of implants, implant migration, clavicle erosion, and postoperative hypoesthesia due to damage to the supraclavicular nerves, have been noted. ^{9 –14} Furthermore, traditional open techniques require large skin incisions resulting in unaesthetic scarring. Wang et al. compared plate fixation with intramedullary fixation for midshaft clavicular fracture, and they reported that plate fixation is biomechanically superior to intramedullary fixation, but its disadvantages include the necessity for increased exposure and soft-tissue stripping, increased risk of damage to the supraclavicular nerve, slightly higher infection rates, hypertrophic scars, and the risk of refracture after plate removal. ¹⁵ Therefore, closed techniques for clavicle fractures have been tried. Closed reduction and fixation of the clavicle fracture can be done using elastic nailing, cannulated screws, or pins. ^{16 –18} If needed, the fracture site can be opened through a much smaller incision compared to standard open methods. It can avoid soft-tissue stripping and unsightly scars that the complicate standard open reduction and internal fixation.

Currently, arthroscopic surgery has been popularized in orthopedic surgery especially periarticular and intra-articular surgery. Although earlier arthroscopic techniques focused on intra-articular ligament and cartilage surgery, they have become widely used in intra-articular and periarticular fracture surgery. ^{19 –21} Ji et al. recently reported on the arthroscopic suture anchor fixation of greater tuberosity fractures of the shoulder and emphasized that the arthroscopic technique showed competent results in both the treatment of the greater tuberosity fracture and concomitant periarticular pathology, including rotator cuff tears. ²² Furthermore, arthroscopy-assisted techniques are widely used for coracoclavicular ligament augmentation or reconstruction in acute or chronic acromioclavicular joint dislocation. ^23,24 Arthroscopy-assisted fracture surgery allows anatomical fracture reduction without extensive soft-tissue dissection and precise diagnosis about intra-articular structures. ^{25 –27}

This article presents a novel technique for the fixation of clavicle shaft fractures using an arthroscopic technique.

Patient management and surgical technique

Indications

Preoperatively, the authors checked plain radiographs to assess the fracture geometry (Figure 1). Indications for the arthroscopically assisted surgical technique included acute shaft fractures within 2 weeks, with a displacement over 100% of the thickness of clavicle shaft, with a shortening over 20 mm after manual reduction (Orthopaedic Trauma Association [OTA] classification 15-B1). ²⁸ Severely comminuted fractures (OTA classification 15-B2, 15-B3) and clavicle fracture distal to the coracoclavicular ligament (OTA classification 15-C) were excluded from the study.

Figure 1.

(a) and (b) Preoperative plain radiograph. A 56-year-old woman visited the emergency medical center with left shoulder pain stemming from a fall on the shoulder. The plain radiograph showed an acute midshaft clavicular fracture with minimal comminution.

Operative technique

Under general anesthesia, the patient was positioned in beach chair position on a radiolucent operating table. The fluoroscopy was positioned to access a 45° caudal view and cephalic view. The affected extremity and shoulder were draped free to expose the full extent of the clavicle in the operative field. Prophylactic preoperative antibiotics (ampicillin–sulbactam 1.5 g) were injected intravenously just before the skin incision was made.

The clavicle fracture was outlined with a skin marker. Two primary portals were made. The viewing portal was made 2 cm anterior to the fracture site. The working portal was made 2 cm lateral to the fracture site. An additional working portal could be used for the guide wire insertion and screw placement (Figure 2). The 30° arthroscope was inserted into the fracture site through the viewing portal. Hematoma and interposition soft tissue around fracture site were removed using a motorized shaver and cautery device through the working portal. The fracture geometry was clearly visualized (Figure 3(a)). For intramedullary screw fixation, a guide wire was percutaneously inserted from the posterolateral skin of the fracture site to the medial fragment under arthroscopic guidance (Figure 3(b)). A guide wire was drilled forward to the medial fragment through the anterior skin. The guide wire was pulled out back from the anterior skin until the posterior end of guide wire was placed at the fracture site (Figure 3(c)). Under arthroscopic guidance, the fracture site was reduced using a towel clip percutaneously. When the reduction was acceptable under arthroscopy, the guide wire was drilled backward to the medullary cavity of lateral fragment by passing through the fracture site (Figure 3(d)). After the reduction was confirmed by fluoroscopy, the appropriate length of 4.0-mm intramedullary cannulated screw (partially threaded, Biomet, Indiana, USA) was inserted from the lateral to the medial site through the guide wire. The fracture site was compressed and fixed by inserting the cannulated screw (Figure 3(e)), and the final reduction state was confirmed by arthroscopy and a plain radiograph (Figure 3(f)).

Figure 2.

Surface marking of the fracture and arthroscopic portal. A viewing portal was made 2 cm anterior to the fracture site and a working portal was made 2 cm lateral to the fracture site. (A: viewing portal, B: working portal, C: fracture site, Co: coracoid process)

Figure 3.

Arthroscopy-assisted reduction and internal fixation using an IM cannulated screw. (a) The fracture site was observed through a viewing portal. The medial and lateral fracture fragment was identified and debridement of the hematoma from the fracture site was performed using a shaver and a cautery device. (b) A guide wire was percutaneously inserted into the medial fracture fragment through the fracture site. (c) A guide wire was then drilled back out to the anterior skin until the posterior end of the guide wire was placed at the fracture site. (d) After fracture reduction, a guide wire was drilled to the lateral fragment by passing through the fracture site. (e) The fracture site was reduced by the insertion of the cannulated screw. (f) The final reduction state was confirmed by plain radiograph. IM: intramedullary.

Postoperative management

Shoulder joint immobilization was maintained with a standard protective sling for 4 weeks. Active elbow flexion/extension, forearm supination/pronation, and active hand and wrist motion were allowed from the first day after the operation during the sling-wearing period. An accelerated shoulder rehabilitation program was started at the postoperatively 4 weeks. This entails passive overhead stretching with a rope and pulley and passive internal and external rotation exercises. Active strengthening and rehabilitation of the rotator cuff, deltoid, and scapular stabilizers were initiated at 10–12 weeks after the operation. All sports activities and heavy manual works were permitted at around the postoperatively 6 months after confirming the bone union with plain radiography.

Clinical experience

From June 2013 to December 2013, three patients underwent fixation of clavicle fractures with an arthroscopically assisted technique. The average age of the patients was 48.3 years (range: 28–54 years). All patients were injured by falls on the shoulder, and they underwent surgical treatment within 5 days of their respective injuries. All surgical procedures were conducted by one senior surgeon (the first author with 20 years’ experience). Mean surgical time was 64.7 min. One patient had simple oblique fracture of diaphysis (OTA classification 15-B1.2), and two patients had simple transverse fracture of diaphysis (OTA classification 15-B1.3).

Mean follow-up period was 21.7 months (range: 17–24 months). Follow-up plain radiographs and computed tomogram were checked at 3, 12 months postoperatively, and the last visit (Figure 4). Full range of motion was obtained at 2.7 months postoperatively (range: 2–3 months). There were no delayed union or nonunion, and complete bony unions were obtained at 5 months postoperatively (range: 3–6 months). One patient complained about skin irritation due to distal portion of cannulated screw. The study protocol was approved by the institutional review board of our hospital. Written informed consent was obtained from every subject.

Figure 4.

Three months after the surgery. (a) and (b) Plain radiograph and computed tomograph showed the complete union of the fracture. (c) and (d) Minimal operation scars were shown.

Discussion

For the clavicle shaft fracture, various treatment methods have been proposed. Earlier, it was believed that nonoperative treatment with immobilization in a sling or shoulder immobilizer regardless of the displacement yielded satisfactory outcomes with nonunion rates less than 1% and little residual deformity and weakness. ^29,30 However, Robinson et al. described a 21% nonunion rate for displaced midshaft clavicle fractures. ² In addition, Nowak et al. showed that 46% of 208 adult patients with conservative treatment of clavicle fractures complained of persistent discomfort and weakness. ³¹ Hill et al. discovered that fractures with greater than 2 cm of shortening on injury radiographs had a higher risk of poor outcomes and nonunion. ³ The Canadian Orthopaedic Trauma Society showed that radiographic union occurred 12 weeks sooner in operative patients. ³² There were fewer nonunions and no malunions in the operative group. One year after treatment, the operative group was more satisfied with their shoulder appearances with improved functional outcomes based on both disabilities of the arm, shoulder, and hand and Constant scores. ^32,33 However, several complications related to surgery were reported, such as breakage, loosening, implant migration, and clavicle erosion. ^{10 –13} The traditional open method requires large skin incisions and reoperation for implant removal. Plating of acute clavicle fractures might provide immediate rigid fixation, pain relief, and early rehabilitation. Insertion of an intramedullary device is another option for fixation. Although a meta-analysis of randomized controlled trials revealed no differences in treatment outcomes between plating and intramedullary fixation, plating resulted in an increase in complaints due to symptomatic implant irritation. ³⁴

Currently, arthroscopy-assisted techniques are becoming widely used in intra-articular and periarticular fractures of the shoulder including greater tuberosity fractures of the proximal humerus, glenoid fractures, and clavicular fractures. ^{21,22,24,35,36} Kim et al. introduced an arthroscopic reduction and internal fixation technique for displaced glenoid rim and greater tuberosity fractures. ³⁵ They emphasized that the anatomic reduction of the fracture could be achieved with arthroscopically assisted direct fracture visualization. An arthroscopy-assisted technique could be used not only in the glenohumeral joint and subacromial space, but also in periarticular spaces, including the subclavicular space. Nourissat et al. used an arthroscopic technique to stabilize distal clavicular fracture. ³⁶ They approached the coracoid process and subclavicular space using arthroscopy. The authors attempted arthroscopy to advance more medially into the clavicular midshaft area.

The authors used a 4.0-mm partially threaded cannulated screw as a fixation device. ³⁷ Intramedullary fixation can be done with elastic nails and pins. ³⁸ They do not possess a lag effect as an integral part of their design, as does the partially threaded cannulated screw. The pins or nails are associated with occasional migration through the skin with a subsequent infection and loss of fixation, or a more serious migration into vital organs. ^{13,38 –43} Our method has the advantages of being an intramedullary fixation, as there is less surgical trauma to the soft tissues than with plating.

Rotational instability is theoretically a disadvantage of intramedullary fixation of the clavicle. In our method, the fixation was stable in all directions intraoperatively, as confirmed by live fluoroscopy during range of motion, and there was no change in screw position at the postoperative follow-up. The reason may due to the three-point fixation offered by the curvature of the bone, the relatively large diameter of the screw that almost fully occupies the medullary cavity, as well as the intramedullary compression applied by the lag effect of the partially threaded screw.

Application of the arthroscopy-assisted technique using a cannulated screw for displaced clavicular shaft fractures might not be suitable for patients with small medullary canals or severely comminuted fractures. In comminuted fractures, the restored length should be determined carefully by comparing the preoperative radiographic assessment of the fragments with the intraoperative findings. Further augmentation of the fracture site or fixation of the butterfly fragment could be achieved through the use of a wire or suture. If the fracture proves to be too comminuted to reduce under an arthroscopic procedure, surgeons should not hesitate to shift to open surgery.

Arthroscopic fracture fixation techniques decrease postoperative pain, minimize hospital stay duration, improve cosmetic problems, and reduce health costs. However, they are technically demanding, requiring experienced arthroscopic skills and a reasonable learning curve. The difficulty of this procedure is finding the appropriate entry through the fracture site in the medial fragment. Arthroscopic dissection must be done carefully, step by step, to avoid any vascular or neurological damage. Furthermore, this technique is only suitable to distal one-third shaft fracture. It is difficult to use this technique to operate other location of clavicle fractures, including midshaft fracture. Therefore, non-comminuted simple fractures of the distal one-third shaft would be better suited for this procedure.

Conclusion

With the development of arthroscopic techniques and devices, it is now possible to treat clavicle shaft fractures with a minimally invasive arthroscopy-assisted procedure. The preliminary results are encouraging, although a longer follow-up study to determine the state indications and limits of this procedure is needed.