Diagnosis and Treatment of Clavicle Fractures

Introduction

Clavicle fractures are relatively common and usually result from direct or indirect trauma to the shoulder region. Studies in the early 1960s reported that the nonunion rate of clavicle fractures was less than 1%, and conservative treatment resulted in high patient satisfaction; with the recent development of medicine, surgical treatment has achieved significant efficacy; therefore, clinicians working in the emergency department or general outpatient clinic should be familiar with the common manifestations and complications of this injury and its basic management.

Epidemiology

Clavicle fractures account for 2.6%-5% of all adult fractures [1,2]. A European study that included 1,000 consecutive clavicle fracture cases found [3,4] that more than 66% of clavicle fractures occurred in the middle 1/3 of the clavicle, approximately 25% were lateral 1/3 fractures, and 3% were medial 1/3 fractures. The incidence of clavicle fractures showed a bimodal distribution, occurring primarily in men under 30 years of age, followed by those over 70 years of age.

Clinical Anatomy

The earliest of the human skeleton to begin ossification is the clavicle, the only bony connection between the upper arm and the trunk, which articulates distally with the acromion, the acromioclavicular (AC) joint, and proximally with the sternum, the sternoclavicular (SC) joint. These joints are called atypical synovial joints because they are lined with fibrocartilage rather than hyaline cartilage. The clavicle is anchored to the scapula by the acromioclavicular and rostroclavicular ligaments and is attached to the sternum by the sternoclavicular ligament.

The clavicle is “S” shaped. The proximal half-arc projects anteriorly, leaving room for the neurovascular bundle of the upper extremity. The distal half of the arc projects backward (concave) and then joins the scapula (rostral process and acromion). Fractures of the clavicle usually occur at the junction of the two arcs (mid-arc), most likely due to the lack of ligaments attaching to neighboring bones in this region and because it is the weakest part of the clavicle. When a clavicle fracture is displaced, the proximal segment is almost always pulled upward (cephalad) by the sternocleidomastoid muscle (attached to the proximal end of the clavicle) and the distal segment is displaced downward (caudad) by the weight of the upper arm, and the clavicle tends to “shorten” (i.e., the fracture ends intersect each other), primarily due to the contraction of the subscapularis and pectoralis major (which internally rotates the upper arm). This is mainly due to the contraction of the subscapularis and pectoralis major muscles (which internally rotate the upper arm and pull it toward the chest).

Features

The goal of clavicle fracture treatment is to minimize pain and restore joint function. Most clavicle fractures are still treated primarily conservatively (usually shortened by no more than 15 mm); conservative treatments such as figure-of-eight bandages, forearm slings, Sayre bandages, Velpeau immobilization suits, and immobilization. Suspension immobilization is performed in the acute phase, and early range of motion training and strength exercises are usually performed 2-6 weeks after the fracture when pain resolves. The use of figure of 8 bandages is not recommended as it can lead to axillary pressure sores and more non-union of the fracture [5,6].

History and Physical Examination

Clavicle fractures are caused by direct impact to the shoulder following a fall and are commonly seen in outdoor sports in the young and in inadvertent falls in the elderly. It is important to define the mechanism of injury. High-energy injuries may combine with head and chest injuries, whereas fractures resulting from minor trauma may be pathologic. Distraction injuries require early initiation and careful exclusion of scapular chest wall separation, neurologic and vascular injuries. Clinically, there is swelling and ecchymosis at the fracture site, combined with deformity and tenderness. Attention should be paid to the soft tissues for jacking up, which may cause skin necrosis and ulceration.

Imaging

Most fractures can be diagnosed by simple anteroposterior radiographs. 20° head tilt radiographs eliminate the effect of overlapping thoracic cavities. Patients should be radiographed in the self-supporting position to better visualize fracture displacement. Weight-bearing for radiographs is helpful in assessing the integrity of the rostral clavicular ligament in distal clavicle or acromioclavicular joint injuries.CT helps to visualize complex scapular girdle injuries and provides better visualization of possible proximal clavicle injuries at the sternoclavicular joint. Taking a chest radiograph helps to rule out an associated thoracic injury, and shortening can be assessed by comparing it to the contralateral clavicle, as well as ruling out scapulothoracic wall separation.

Types

AO/OTA Fracture Dislocation Typing: The clavicle fracture code 15 consists of three sites: 15.1 proximal (medial), 15.2 diaphysis, and 15.3 distal (lateral). Proximal (medial) and distal (lateral) fractures are categorized as type A (extra-articular), type B (partially intra-articular), and type C (completely intra-articular). Trunk fractures are categorized as type A (simple), type B (wedge), and type C (comminuted).The AO/OTA classification of fractures and dislocations does not take into account the degree of displacement of the fracture, and is currently of limited use in the treatment of clavicle fractures and in determining prognosis.

Allman typing is based on the location of the fracture (I: medial, cadent 1/3, II: lateral 1/3, III: medial 1/3) (Fig. 7.2.1).

Craig refined this classification again on the basis of Allman, with I being the middle 1/3 of the clavicle; type II being the outer 1/3 of the clavicle, which was then divided into 5 types based on fracture displacement and relationship to the rostral clavicular ligament; and type III being the fracture of the inner 1/3 of the clavicle, which was divided into 5 types based on the degree of fracture displacement and whether or not the fracture was intra-articular.

Neer's typing of lateral 1/3 fractures emphasizes the importance of the rostral-clavicular ligament: type I occurs distal to the rostral-clavicular ligament, with the medial fracture block displaced superiorly; type II involves the rostral-clavicular ligament and results in the medial fracture block being displaced superiorly; and type III extends to the acromioclavicular joint with the rostral-clavicular ligament remaining intact.

Edinburgh typing is a system of classification of diaphysis fractures according to the degree of displacement and comminution.1 Type 1 fractures involve the medial end, type 2 are diaphysis fractures and type 3 are lateral end fractures. The fractures of the diaphysis are classified according to the presence or absence of cortical contact between the fracture fragments into types A and B. Type 2A fractures are further classified as nondisplaced (type 2A1) and angulated (type 2A2),2B fractures are classified as simple or wedge-shaped (type 2B1) and comminuted (type 2B2).3 Type 1 fractures involve the medial end of the diaphysis and type 3 is the lateral end of the diaphysis. Medial and lateral end fractures are subdivided into subgroups 1 and 2 according to whether the adjacent joint is involved.

Similarly there is Rockwood typing, Jager typing, and Breitner typing.

Surgical indications

Specific fractures

1, open fracture; 

2, displacement >2 cm; 

3, shortening >2 cm; 

4, comminution of fracture fragments (>3); 

5, multi-segment fracture; 

6, underlying open fracture with soft tissue injury; 

7, significant deformity (displacement and shortening); 

8, scaphoid injury.

Compound injuries

1, Combined ipsilateral upper extremity injury;

2, Floating shoulder injury;

3, multiple injuries;

4, fracture combined with neurovascular injury;

5, ipsilateral multiple rib fractures combined with chest wall deformity;

6, clavicle shortening to form a winged shoulder;

7, Bilateral clavicle fractures.

Patient Factors

1, Patients with multiple injuries require early upper extremity weight bearing;

2, Patients requiring rapid return to function (e.g., elite and competitive sports).

Timing of surgery

Surgery should be performed without delay when absolute indications for surgery are present.

A delay in surgery beyond 2-3 weeks in relative indications may increase the difficulty of fracture reduction, especially when preparing for closed reduction internal fixation by percutaneous techniques.

Surgical access

The patient is placed in the beach chair position or semi-sitting position. The affected shoulder is padded underneath to elevate the clavicle for ease of surgery, and the arm is toweled to allow intraoperative mobilization. A transverse incision along the long axis of the clavicle or a saber incision parallel to the langer pattern may be chosen.

Note: A transverse incision provides greater extension, while a longitudinal incision reduces the risk of supraclavicular nerve injury and is more aesthetically pleasing.

Internal Fixation

3.5 Systematic compression plates, reconstruction plates, or plastic LCPs can be used to fix clavicle fractures. Plates are smoothly placed above or anterior to the clavicle. Plates are stronger in biomechanical injuries when placed superiorly, especially if there is a comminuted fracture below, and are simpler to visualize. Bicortical fixation of the screws is necessary, and the holes should be drilled with great care, as there is a risk of injury to the nerves and blood vessels below. Advantages: safe drilling of the anterior plate screw channel, plate apposition, easy contouring.

Note: Bone grafting is usually not required for the initial procedure; after internal fixation, it is critical to adequately suture the myofascial layer to cover the plate and prevent infection.

Intramedullary fixation

Current intramedullary fixation devices include Kirschner pins, Rockwood pins, Hagie pins, titanium elastic intramedullary pins, hollow screws, and elastic locking intramedullary nails; e.g., titanium elastic nails do not allow for static locking, do not allow for control of length and rotation, and may result in secondary shortening when used for comminuted fractures. The intramedullary nailing technique can only be applied to simple, transverse or oblique clavicle fractures.

Advantages

smaller incision, more aesthetic, less soft tissue stripping, lower risk of endophyte protrusion, and stability associated with scab formation.

Disadvantages

skin irritation or defects at the point of entry.

Note:Closed reduction of clavicle fractures is sometimes difficult and overexposure of the operator's hand to radiation is avoided during surgical maneuvers.

Minimally invasive plate fixation

Minimally invasive plate osteosynthesis of the clavicle is thought to provide greater biomechanical strength while avoiding the disadvantages of open plate fixation or intramedullary fixation.

Intraoperative placement of the 3.5 system LCP anterior to the clavicle, preferably anteriorly below the clavicle, allows reference to the healthy clavicle, making it easier to shape the plate in advance and to obtain a longer screw aperture.

Early application of minimally invasive plate osteosynthesis may be associated with supraclavicular nerve injury, poor alignment or shortening of pairs of wires affecting function, and plate bending or fracture.

Plate fixation of fractures of the lateral end of the clavicle

The choice of plate implants depends on the size of the lateral bone block. A minimum of 3 bicortical screws are required for the lateral bone block. Ideally, tension screws should be used for oblique fractures. If the bone block is too small for fixation, a clavicle hook plate may be used.

Treatment of acromioclavicular joint dislocation

Acromioclavicular joint injuries account for 12% of scapular girdle injuries and often occur in filled contact athletes.

The most commonly used staging system is the Rockwood staging. Type I is a sprain of the acromioclavicular ligament with the rostroclavicular ligament intact; type II is a tear of the acromioclavicular ligament with the rostroclavicular ligament intact; type III is a tear of both the acromioclavicular ligament and the rostroclavicular ligament; type IV is a posterior displacement of the distal clavicle impaling the trapezius; type V is a complete tear of both the acromioclavicular joint and rostroclavicular ligament, with more than 100 percent displacement of the joint; and type VI injuries are very rare, with the distal clavicle displaced downward below the rostral process.

Conservative treatment with short-term braking with a cantilever sling is recommended for type I and type II injuries. The management of type III injuries is controversial, with some literature suggesting that conservative treatment is indicated for active young adults. Functional recovery is good although there may be varying degrees of deformity in appearance. Type IV - VI injuries are more severe and surgical intervention is recommended.

Currently, the commonly used surgical procedures are: Bosworth rostral locking screw technique with one-stage repair or no repair of the ligament;, clavicle hook plate fixation, similar to lateral end of clavicle fracture; Tightrope's tab plate fixation or anchor pinning suture through an arthroscope or a small incision; and rostral locking ligament suture or reinforced suspension, with artificial material or tendon between rostral eminence and the clavicle.

It is not clear which surgical technique is more advantageous, and although there may be some degree of loss of resurfacing, the ultimate efficacy of all of these techniques is satisfactory.

Treatment of medial end clavicle fractures and sternoclavicular joint dislocations

These injuries are relatively rare, and again there is a lack of treatment guidelines based on evidence-based medicine.

Medial clavicle fractures are often extra-articular fractures with insignificant displacement and can be treated conservatively. The epiphysis of the medial end of the clavicle typically closes at 23-25 years of age and is the last epiphysis to close in the body. Therefore, many medial injuries are actually epiphyseal plate fractures of Salter-Harris type I or II. Conventional X-rays are difficult to diagnose, with the advantage that a 40° head tilt radiograph and comparison to the healthy side may reveal displacement of the medial end of the clavicle, and CT provides the best diagnostic imaging.

Fractures or dislocations that are displaced anteriorly can usually be closed and repositioned, but are often unstable and lobotomized for re-displacement. Palliative care is recommended for persistent dislocations or displacements because they often do not result in functional impairment. Dislocation of the medial end of the clavicle posteriorly rarely results in upper mediastinal injury, including vascular injury or even tracheal obstruction and airway compression. For dislocations and fractures where the medial fragment is too small, plates can be bridged across the joint for fixation to the sternum.

Other fixation methods

e.g. external fixation with stent, external fixation with clavicle plate, etc.

Postoperative management

The upper arm should be immobilized in a sling and shoulder pendulum training should be started immediately. 2 weeks later, the patient should be followed up to check the wound and review the X-rays, while the forearm sling can be removed and unrestricted joint mobility training can be started, but the patient should be told not to lift weights with the affected limb. Strength training can be started at 6 weeks postoperatively when signs of bony healing appear. Contact sports or extreme sports should be avoided for 3 months after surgery until the fracture has completely healed.

Complications.

Early complications

Postoperative wound infections can occur in up to 4.8% of cases;

Numbness in the subclavian region is the most common complication, with a natural history study of up to 83% of patients with this symptom, which diminishes over time and does not lead to significant dysfunction, although it may persist up to 2 years postoperatively;

Endophyte protrusion and skin agitation, common with the use of voluminous plates or nail tails without good soft tissue coverage;

re-fracture, which may occur after both surgical and conservative treatment; post-surgical re-injury may result in bending or breaking of the endoprosthesis, or fracture around the endoprosthesis;

nonunion, with a 15% nonunion rate with conservative treatment and a 2% nonunion rate with surgical treatment for completely displaced diaphyseal fractures; complete displacement of the fracture, shortening greater than 2 cm, smoking, increasing age, high-energy injuries, re-fracture (mechanical instability), recalcitrant diaphyseal dislocations, poor bone quality, and excessive bone loss.

Late complications

Osteoarthritis of the acromioclavicular joint occurs more frequently with intra-articular fractures (Edinburgh type 3B2); when symptomatic and conservative treatment is ineffective, the distal clavicle may be resected arthroscopically or by open surgery;

Deformity healing, which occurs to varying degrees in all conservatively treated displaced fractures; shortening of the scapular girdle accompanied by rotation of the distal fracture block may result in decreased ultimate shoulder strength and endurance, especially in shoulder abduction; narrowing of the thoracic outlet may result in symptoms of brachial plexus compression; and malalignment of the scapulothoracic wall joints can cause anterior tilting of the scapula and produce shoulder pain and myalgias, if it is clear that the symptoms are from deformity When healing occurs, osteotomy correction and plate fixation are feasible depending on the patient's needs.

Prognosis and outcome

A related study in Europe reported that surgical treatment of displaced midclavicular fractures was effective, and its meta-analysis showed that the incidence of malunion leading to fracture nonunion and symptom-producing malunion was significantly lower in the surgical group than in the conservatively treated group when surgery was compared with conservative treatment; in addition, the surgical group had reduced pain early on, and the improvement in Constant and DASH functional scores was more pronounced.

Summarize

Most clavicle fractures are caused by direct or indirect violence, and the treatment can be categorized as conservative or surgical treatment. In terms of treatment, although most clavicle fractures without significant displacement can be treated conservatively, the surgical treatment option for fractures with significant displacement is controversial. For displaced clavicle fractures, surgical treatment has a higher rate of bone healing and early functional outcomes compared with conservative treatment.

References

[1] Postacchini F, Gumina S, De Santis P, Albo F. Epidemiology of clavicle fractures. J Shoulder Elbow Surg 2002; 11:452.

[2] Eiff, MP, Hatch, et al. Clavicle and scapula fractures. In: Fracture Management for Primary Care, 2nd ed, WB Saunders, Philadelphia 2002. p.198.

[3] Robinson CM. Fractures of the clavicle in the adult. Epidemiology and classification. J Bone Joint Surg Br 1998; 80:476.

[4] Neer CS 2nd. Fractures of the distal third of the clavicle. Clin Orthop Relat Res 1968; 58:43.

[5] Andersen K, Jensen PO, Lauritzen J. Treatment of clavicular fractures. Figure-of-eight bandage versus a simple sling. Acta Orthop Scand 1987; 58:71.

[6] Ersen A, Atalar AC, Birisik F, et al. Comparison of simple arm sling and figure of eight clavicular bandage for midshaft clavicular fractures: a randomised controlled study. Bone Joint J 2015; 97-B:1562.