The clavicle is one of the most commonly fractured bones; clavicular fractures represent 2.6% to 5% of all fractures.1,2 The incidence of clavicular fracture in adults is estimated to be 71 in 100,000 for men and 30 in 100,000 for women, with the incidence of midshaft fractures decreasing with increasing age. Midshaft fractures account for 69% to 82% of all clavicular fractures.1–5 Midshaft fractures are more common in children and young adults. The incidence of high-energy clavicular fractures with comminution, displacement, and shortening appears to be increasing.2
Traditionally, fractures of the clavicle have been treated with closed reduction. More than 200 methods have been described for closed reduction, yet a classic textbook recognizes that “reduction is practically impossible to maintain, and a certain amount of deformity is to be expected, generally compatible with satisfactory return of function in the shoulder.”6 The same textbook states that even completely displaced fractures “generally do well with non-operative management….”6
However, most previous studies describing the results of clavicular fracture have used surgeon-based or radiographic outcome measures that equate union with success. Very few studies on clavicular fracture have been published using patient-based outcomes such as the Medical Outcomes Study 36-Item Short Form (QualityMetric, Lincoln, RI) or the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH; Institute for Work and Health, Toronta, Canada, and the American Academy of Orthopaedic Surgeons [AAOS]). Recent studies have indicated that outcomes are not always excellent, particularly in highenergy fractures.7–11 These studies raise the question whether acute midshaft clavicular fractures should be internally fixed.
Anatomy and Function
The clavicle is the first bone to ossify in the fifth week of fetal life, and it is the only long bone to ossify by intramembranous ossification. Initial growth up to age 5 years arises from the ossification center in the central portion of the clavicle, with continued growth occurring at the epiphyseal plates at the medial and lateral ends of the bone. The medial growth plate, typically the only plate seen radiographically, accounts for up to 80% of longitudinal growth. The medial growth plate is the last physis to close, generally at age 22 to 25 years. The clavicle is subcutaneous, with only the supraclavicular nerves crossing the bone. However, several fascial layers and muscles attach to the bone itself and help to create the predictable deformity seen with fractures. The proximal fragment is pulled superiorly and posteriorly by the sternocleidomastoid muscle. The distal segment sags forward and rotates inferiorly because of the weight of the upper extremity and, to a lesser extent, the pull of the pectoralis muscle on the humerus.
The clavicle is a strut that connects the upper extremity to the trunk and is the only link to the axial skeleton. It also provides protection for the adjacent axillary and subclavicular neurovascular structures and the apex of the lungs. Laterally, the clavicle is secured by the acromioclavicular (AC) and coracoclavicular ligaments where it articulates with the acromion. Medially, the clavicle articulates with the sternum and is strongly secured to the first rib by the intraarticular sternoclavicular (SC) joint cartilage, the oblique fibers of the costoclavicular ligaments, and the subclavius muscle. The clavicle is S-shaped and double-curved, concave ventrally on its lateral half and convex ventrally on its medial half. The crosssectional geometry changes from flat laterally to tubular centrally to triangular medially (Figure 1).
The shape of the clavicle and the ligamentous and muscle attachments play a role in fracture patterns. The junction of the outer and middle thirds is the thinnest part of the bone and is the only area not protected by or reinforced with muscle and ligamentous attachments, thereby rendering it prone to fracture, particularly with axial loading.12 This helps to explain why the middle third is the most common site of fracture, occurring at the junction where the bone geometry changes from flat to tubular.
The motion of the clavicle is ultimately linked to the surrounding motion of the scapula because of the anatomic attachment to the scapula through the AC joint and to the sternum through the SC joint. Motion of the clavicle occurs with elevation and abduction of the arm. During elevation, with respect to the SC joint, the clavicle undergoes elevation of 11° to 15°, retraction of 15° to 29°, and posterior long-axis rotation of 15° to 31°, with the magnitude and planes varying among subjects.13 Other studies suggest that rotation may be as much as 50° and elevation as high as 30°.14 More importantly, clavicle rotation is relatively small until humeral elevation exceeds 90°; thus, early rehabilitation that avoids over-the-shoulder activity will significantly limit rotational forces at the site of a clavicular fracture.15
Mechanism of Injury
Midshaft clavicular fractures have traditionally been thought to occur from a fall on an outstretched hand. However, a biomechanical analysis of the forces demonstrated that a direct injury from the shoulder (rather than the hand) that produces a force equal to the body weight would exceed the critical buckling load and result in a midshaft clavicular fracture.16 Several studies have demonstrated that a direct fall or blow onto the point of the shoulder accounts for 85% to 94% of the injuries.2,3,5,16,17 When the forces are transmitted through the arm, as with a fall on an outstretched hand, the forces are not directly delivered to the clavicle; thus, they are unlikely to produce a midshaft fracture. This mechanism accounts for 2% to 5% of all midshaft fractures. A direct blow to the clavicle, such as from a hockey stick or a seat belt shoulderstrap injury, also may produce a fracture and accounts for 10% to 13% of midshaft fractures in most studies. 16 Although rare, direct force on the top of the shoulder may drive the midshaft clavicle against the first rib, resulting in a fracture.
Clavicular fractures have been classified by Allman18 into three anatomic regions, with the middle third being group I. The classification system of the Orthopaedic Trauma Association separates diaphyseal clavicular fractures into three types: 06-A (simple), 06-B (wedge) and 06-C (complex).19 Each type is further broken down into three groups.
The system developed by Robinson3 divides midshaft clavicular fractures into type 2A (cortical alignment fracture) and type 2B (displaced fracture). In an effort to provide direction for treatment and prognosis, Robinson further divides these into subgroup types 2A1 (nondisplaced), 2A2 (angulated), 2B1 (simple or wedge comminuted), and 2B2 (isolated or comminuted segmental) (Figure 2). Robinson's classification system has demonstrated satisfactory levels of interobserver and intraobserver reliability and reproducibility. However, additional studies are needed to determine whether this classification system will reliably predict treatment and functional outcomes.
Often with clavicular fracture, a bruise or abrasion is seen, either over the point of the shoulder (indicating a direct blow) or over the midline (suggesting a seat belt shoulder-strap injury). The shoulder has a droop, the scapula appears slightly internally rotated, and the shoulder appears shortened relative to the opposite side. This characteristic deformity is produced by the pull of muscles attached to the clavicle. Immediate swelling may obscure the deformity of the bone, which will be seen on radiographs if the fracture is displaced. Palpation over the area will reveal tenderness, and gentle manipulation may produce crepitus and motion at the fracture site. A nondisplaced or minimally displaced fracture may be suspected when pain and/or skin changes are present over the clavicle.
Because middle third fractures frequently occur with high-energy trauma, a complete examination should be performed to avoid missing associated injuries. Skeletal injuries include fracture-dislocations of the SC and AC joints or, in younger patients, physeal injuries. Chest wall trauma may result in high rib fractures, scapular neck and body fractures, and a pneumothorax or hemothorax. Although acute brachial plexus injury is rare, the ulnar nerve is at highest risk because of its location adjacent to the middle third of the clavicle. When a nerve injury is identified, a thorough vascular examination and evaluation of the scapulothoracic articulation should be undertaken to avoid missing an associated injury. Penetrating trauma is typically the cause of vascular injury. However, vascular injury can occur from blunt trauma, resulting in spasm or thrombosis of the subclavian vessels.
To determine the fracture pattern and displacement, radiographs in two projections are necessary. A standard anteroposterior view should be accompanied by a 45° cephalic tilt view (Figure 3). The shoulder girdle and upper lung fields should be carefully assessed to avoid missing associated fractures or a subtle pneumothorax. The radiographic evaluation should assess the fracture pattern, presence of comminution, displacement, and shortening or distraction of the fracture.
Several radiographic findings can help guide the surgeon's choice of treatment. Displacement without bony contact, especially with a transversely displaced fragment, is a risk factor strongly predictive of long-term sequelae.7 Additional radiographic parameters predictive of increased risk for pain, limitation of motion, or nonunion include an overall displacement of the fracture ends >1.5 cm. This displacement includes shortening, distraction, or separation of the ends in the anterior or posterior direction in any radiographic view.20–22 A second view, at least 45° off plane from the first, helps to further delineate the displacement. Often, the displacement is difficult to assess on a single radiograph. For example, as seen in Figure 3, both views reveal distraction at the fracture site of at least 1.5 cm.
The primary goal in treatment is to restore shoulder function to the preinjury level. By allowing the clavicle to heal with minimal deformity, loss of motion and pain can be minimized. Indications for nonsurgical treatment include a nondisplaced or minimally displaced midshaft clavicular fracture. Indications for surgical treatment include open fractures and fractures associated with skin compromise or with neurologic or vascular injury.
Relative surgical indications include certain multiple-system traumatized patients, a floating shoulder, and a painful malunion or nonunion. More recently, relative indications for surgical treatment have been expanded to include high-energy closed fractures with >15 to 20 mm of shortening, fractures with complete displacement, and fractures with comminution.23–26 Although these recently adopted indications have received attention in the current literature, articles dating as far back as the 1960s have described similar surgical indications—including Neer's article,17 which is often cited as support for nonsurgical management. Randomized controlled trials, one of which has recently been completed, 11 and another that is currently under way, are necessary to determine whether these relative indications should be considered routine and, if so, in which patients with which fracture types.
Historically, nonsurgical treatment has been the mainstay for clavicular fractures. It has varied from plaster shoulder spica casts to benign neglect. Most commonly, a sling or figure-of-8 brace is applied in the acute setting. With either device, immobilization is typically for 2 to 6 weeks, based on the patient's level of comfort. Often, mild discomfort can linger in adults for 3 months. Return to athletics or heavy labor is permitted 4 to 6 weeks after clinical and radiographic union has occurred. Light work with restricted overhead activity can begin once the patient's comfort allows, usually in 2 to 4 weeks after fracture healing.
In a prospective, randomized study,27 26% of patients treated with a figure-of-8 bandage were dissatisfied compared with 7% of those treated with a sling. The patients treated with a sling reported less discomfort. There was no difference in overall healing and alignment of the fractures, indicating that a figure-of-8 bandage does little to obtain or maintain reduction.
Surgical Techniques Plates
Open reduction and internal fixation using plates and screws can be done with the patient in either the supine or the beach-chair position, with the head and neck tilted away from the surgical site. A bump is placed behind the scapula to aid in the reduction. The arm is prepped in the field to allow for traction and manipulation to assist in the reduction. Traditionally, a skin incision is made over the clavicle following Langer's lines, as the skin permits. A newly described alternative is to incise the inferior skin after pulling it over the fracture site.28 As the skin is released, it will fall 1 to 2 cm below the clavicle and prevent the wound from being in contact with the plate on the clavicle. The aim is to improve cosmesis and prevent wound complications. The dissection is taken down to bone with care to identify the cutaneous supraclavicular nerves. When necessary, they can be sacrificed. It is important to inform the patient before surgery of the possibility of a patch of numbness in the skin inferior to the clavicle.
Minimizing subperiosteal stripping with gentle handling of the skin and soft tissue helps avoid complications. The plate usually is placed on the tension side of the bone—for the clavicle, the anterosuperior position (Figure 4). Biomechanically, this position provides the best stability. 29 However, clinically successful treatment with anteroinferior placement also has been described.30 The anteroinferior position, although less favorable biomechanically,29 allows for drilling in a direction away from the subclavian vessels and lung. It also keeps the plate from being placed under the incision. This position theoretically is less likely to cause irritation, thereby decreasing the need for plate removal. However, the anteroinferior position demands additional soft-tissue stripping and a more difficult contouring of the plate compared with the anterosuperior position.
Ideally, a 3.5-mm dynamic compression plate or plate of similar strength should be used, with at least six cortices on each side. Semitubular plates are not as rigid and should not be used.24,31 Reconstruction plates are more easily contoured and have been used with success; however, they account for several failures to obtain union and would not be the author's first choice.24,31 Precontoured plates of suitable thickness offer the advantage of ease of placement without manipulation of the plate. Locked plates are not necessary for the acute plating of nonosteoporotic clavicular fractures; there is no significant advantage over conventional plating, and the cost is higher.
Once plating is completed, the fascia is repaired over the plate, if possible, and the skin incision is closed. Suture closure is preferable to staples. With a sufficiently stable construct, unrestricted shoulder motion is allowed, with the exception of overhead lifting for 6 weeks. Often, the pain relief associated with stabilizing the fracture is dramatic, and efforts to limit the patient's activity may be needed. Pain relief is cited as one of the potential benefits of surgical intervention.
An alternative to plating is intramedullary (IM) fixation. Many variations of IM implants have been described over the past 40 years, including Hagie pins, modified Hagie pins, Knowles pins, Herbert screws, Steinmann pins, elastic nails, cancellous screws, and Kirschner wires.32–36 Modifications in the technique have led to a resurgence of interest in IM fixation of these fractures. The potential benefits of IM fixation compared with plate fixation include less soft-tissue stripping at the fracture site, better cosmesis with a smaller skin incision, easier hardware removal, and less weakness of the bone after hardware removal. Biomechanically, however, the ability to resist torsional forces with IM fixation is much less than that with a plate. Migration of the pins also has been a major concern. Newer designs, which include locking nuts on the lateral end of the IM devices, prevent medial pin migration. Newer techniques that avoid penetration of the medial fragment cortex also prevent medial migration of the devices.34
Patient positioning is similar to that for plate fixation. A small incision is made over the fracture site, exposing the fracture ends. The medial segment is prepared by drilling into the medullary canal, but the anterior medial cortex is not violated. The distal segment is drilled retrograde through the canal, exiting the posterior lateral cortex. The pin is inserted retrograde through the canal and exits through the posterolateral hole and out the skin. Next, the fracture is reduced, and the pin is advanced antegrade across the fracture into the medullary canal of the medial segment. The Rockwood Clavicle Pin (DePuy Orthopaedics, Warsaw, IN) has two nuts that go over the threaded end of the inserted pin posterolaterally. Once the pin is across the fracture, the first nut is inserted posterolaterally, compressing the fracture, followed by the second nut, which is cold-welded to the first. Figure 5 shows the Rockwood Clavicle Pin in place. Some of the IM techniques vary slightly depending on the device, and not all of the techniques allow for fracture compression.
Patients are allowed to begin shoulder motion immediately postoperatively. When rotational stability is a concern, forward elevation should be restricted to 90° and abduction to 90° for the first 4 weeks. The Rockwood pin should be removed at 8 to 14 weeks. In some situations, this can be done under local anesthesia in the office; however, most Rockwood pins need to be removed in the operating room. Some of the other IM devices, such as Herbert screws, do not need to be removed.
As with plating, a major benefit is early return to activities. Several studies have reported athletes' returning to their sport activities by 2 to 3 weeks.35,37
Complications can occur from nonsurgical treatment as well as surgical treatment. Both can produce a cosmetic deformity (Figure 6). Both can result in malunion, nonunion, pain, local tenderness or irritation, and limitation of motion. Other rare complications following surgical or nonsurgical treatment are residual nerve paresthesia; subclavian vessel compression, thrombosis, and pseudoaneurysm; thoracic outlet syndrome; and brachial plexus neuropathy.
Some complications are unique to surgical intervention, such as infection and hardware problems. Infection rates vary from 0% to 18%, with the lower rates reported in the more recent studies.24,31,37,38 Painful, irritating hardware requiring plate or pin removal is reported to be as high as 50% to 100%.24,39 Following plate removal, the risk for refracture ranges from 0% to 8%.24,31 Adhesive capsulitis of the shoulder has been reported with surgical treatment in 0% to 7% of cases.24,28
IM devices are associated with unique complications, including migration of the pin and hardware irritation, resulting in local skin breakdown that often requires antibiotics and, ultimately, hardware removal.39Figure 7 illustrates skin breakdown from an IM pin. Although most of these complications are rare, a second surgery for plate or pin removal is sufficiently frequent to be considered when reviewing treatment choices.
Whether treated nonsurgically or surgically, most clavicular fractures heal without incident when length and alignment are maintained. Acceptable cosmetic and functional results should be expected. Satisfactory results occur less consistently when the fracture fails to heal or heals with a significant deformity.
Most cases of nonunion are symptomatic, presenting with pain, loss of function, neurologic changes, and/or unsightly clavicular deformity. Although clavicular nonunion has not been clearly defined in the literature, most authors concur that nonunion is present when healing has not occurred by 16 weeks.
Traditional thinking is that clavicular fractures treated nonsurgically almost always heal and that surgical treatment increases the risk of nonunion. Rowe4 reported a nonunion rate of 3.7% in patients who underwent surgery compared with 0.8% in those treated without surgery. Neer17 reported nonunion rates of 0.1% with nonsurgical treatment and 4.6% with surgical treatment. Neer17 suggested that the most important causal factor for nonunion of a midshaft clavicular fracture is improper open surgery. This may be true to some extent; aggressive softtissue stripping, inability to reduce the fracture, and inadequate internal fixation all can lead to poor results.
Several recent studies have reported high union rates with surgical intervention using a variety of internal fixation devices, including plating and IM pin or rod fixation.39,40 In addition, there is evidence that the nonunion rate after nonsurgical treatment may be higher than previously reported, particularly in certain fracture types and in certain patients. In their review of 581 nonsurgically treated fractures, Robinson et al20 reported an overall nonunion rate of 4.5% for diaphyseal fractures. Stratification of Robinson's data revealed that women with displaced diaphyseal fractures had a nonunion rate ranging from 19% to 33%. When comminution was combined with displacement, the nonunion rate in women increased to a range of 33% to 47%.41 In addition to fracture fragment displacement, female sex, and comminution, other risk factors identified with nonunion include advancing age, lack of cortical apposition, severity of the initial trauma, the extent of fracture fragment displacement,25 and, arguably, softtissue interposition.42 Early mobilization has not been associated with the development of a nonunion, whether treated surgically or nonsurgically.
A recently published systematic review of the literature on nonunion after treatment of midshaft clavicular fractures revealed a 5.9% nonunion rate in nonsurgically managed fractures.8 In the completely displaced fractures, the rate increased to 15.1%. In surgically treated displaced fractures, plating of 460 fractures resulted in a nonunion rate of 2.2%, and IM fixation of 152 fractures resulted in a nonunion rate of 2.0%.8 These data should be interpreted with caution, however, because most were from evidence-based level III, IV, and V studies (ie, observational, retrospective, case series, and expert opinion studies) rather than from level I and II studies (ie, randomized, prospective studies).
Surgical treatment of nonunion has a high success rate. Techniques include plate fixation with bone graft, IM pin fixation with bone graft, and external fixation. Union rates with each method have been reported to be >92% and as high as 100%.42–45 Plate fixation has the largest support in the literature and is currently the most predictable and recommended treatment for symptomatic nonunion. Other methods may be successful in the hands of an experienced surgeon.
Most nonsurgically treated clavicular fractures heal with some deformity. The literature does not clearly define when a deformity is considered to be a malunion; however, the evidence strongly suggests that some clavicular deformities result in unsatisfactory outcomes. The deformity is a three-dimensional problem; the most consistent characteristic is shortening with inferior displacement of the medial fragment. Symptomatic patients help define the malunion. Symptoms include weakness and pain in the involved shoulder, loss of shoulder motion, loss of endurance, neurologic symptoms consistent with thoracic outlet syndrome and brachial plexus impingement, and cosmetic deformity.46
In 1986, Eskola et al21 noted in 89 patients that shortening >12 mm was associated with increased pain. Wick et al22 concluded in a retrospective study that shortening of 2 cm in midshaft clavicular fractures was associated with an increased risk of pain, limitation of motion, or nonunion. McKee et al9 assessed functional outcome following displaced clavicular fractures and noted significantly inferior scores for both the upper extremity-specific (DASH) outcome scores (P = 0.02) and the Constant scores (P = 0.01) compared with the general population. They concluded that fractures with >2 cm of shortening tended to be associated with decreased abduction strength and greater patient dissatisfaction. Hill et al25 reported on completely displaced middle third clavicular fractures and concluded that final shortening ≥2 cm was associated with an unsatisfactory result but not with nonunion. After closed treatment, 31% of patients were dissatisfied with the final result, 54% were unhappy with the appearance, and 15% of fractures failed to unite. Using the same subjective patient questionnaire as that used by Hill et al,25 Lazarides and Zafiropoulos10 reported that final clavicular shortening > 18 mm in males and > 14 mm in females was associated with unsatisfactory results and with increased patient symptoms.
Ledger et al47 showed the effect of clavicular shortening >15 mm on biomechanical parameters of the shoulder. They found a significant increase in upward angulation (mean, 10.7°; P < 0.005) of the SC joint on the injured side compared with the uninjured side. The muscle torque of the injured arm was significantly weaker than that of the uninjured arm in extension (P < 0.05), adduction (P < 0.05), and internal rotation (P < 0.05).47
These studies indicate that although clavicular deformities are complex and hard to assess, shortening of 1.5 to 2 cm, which results in an increased incidence of clinical symptoms, is one parameter that can be measured. Further investigation is needed to clearly define the patients as well as the fracture deformity that is likely to be symptomatic with a clavicular malunion. In this way, acute surgical treatment could be offered to the patients who are most likely to benefit. In addition, comparative trials are necessary to establish that patients with clavicular fractures that predictably result in deformity have better outcomes when treated surgically rather than nonsurgically. Several randomized trials currently are under way, and one has been completed, assessing the surgical versus nonsurgical management of acute displaced midshaft clavicular fractures. The Canadian Orthopaedic Trauma Society has shown in a multicenter randomized trial of 132 patients that for displaced fractures of the clavicular shaft, surgical fixation with a plate and screws resulted in an improved functional outcome and a lower rate of malunion and nonunion compared with nonsurgical treatment at 1 year.11
Treatment of a malunion consists of surgical correction to restore length, angular deformity, and rotation of the clavicle. Treatment may or may not involve an intercalary bone graft. Often, after removing the callus of the malunion, it is possible to identify the proximal and distal fragments in order to anatomically reconstruct the clavicle.46,48 The benefit of this technique is that there is no donor-site morbidity for a bone graft. When difficulty in determining the length of the malunited clavicle is anticipated, a preoperative radiographic image of both clavicles is helpful. Both IM devices and plates have been used successfully to treat malunions.46,48–50 Treatment of symptomatic malunions has resulted in improvement of the function of the upper extremity, decreased pain, and increased patient satisfaction.46,50
The frequency of comminuted and displaced midshaft clavicular fractures that result from high-energy injuries is increasing. Nondisplaced and minimally displaced fractures should be treated nonsurgically, preferably with a sling for patient comfort; the rates of nonunion, pain, cosmetic deformity, and loss of function are low. However, for specific groups of patients, the risk of complications from nonsurgical management may be significantly higher. These patients include those with completely displaced and comminuted fractures and, possibly, those who are female or of advanced age. The current literature suggests that surgical stabilization, with either plates and screws or with an IM device, should be considered as the preferred treatment option for these more complex acute midshaft clavicular fractures. Further randomized, prospective studies are needed to determine whether the benefits of surgical fixation outweigh the risks and, if so, in which types of patients and for which types of midshaft clavicular fracture.
Evidence-based Medicine: Level I/II prospective studies are references 5, 7, 8, and 27. The remaining references are level III/IV case-control cohort studies or level V, expert opinion.
Citation numbers printed in bold type indicate references published within the past 5 years.
. Postacchini F, Gumina S, De Santis P, Albo F: Epidemiology of clavicle fractures. J Shoulder Elbow Surg
2. Nordqvist A, Petersson C: The incidence of fractures of the clavicle. Clin Orthop Relat Res
3. Robinson CM: Fractures of the clavicle in the adult: Epidemiology and classification. J Bone Joint Surg Br
4. Rowe CR: An atlas of anatomy and treatment of midclavicular fractures. Clin Orthop Relat Res
5. Nowak J, Mallmin H, Larsson S: The aetiology and epidemiology of clavicular fractures: A prospective study during a two-year period in Uppsala, Sweden. Injury
6. Neer CS: Fractures of the clavicle, in Rockwood CA, Green DP (eds): Fractures in Adults
, ed 2. Philadelphia, PA: JB Lippincott, 1981, pp 707-713.
. Nowak J, Holgersson M, Larsson S: Can we predict long-term sequelae after fractures of the clavicle based on initial findings? A prospective study with nine to ten years of follow-up. J Shoulder Elbow Surg
. Zlowodzki M, Zelle BA, Cole PA, Jeray K, McKee MD, Evidence-Based Orthopaedic Trauma Working Group: Treatment of acute midshaft clavicle fractures: Systematic review of 2144 fractures. On behalf of the Evidence- Based Orthopaedic Trauma Working Group. J Orthop Trauma
. McKee MD, Pedersen EM, Jones C, et al: Deficits following nonoperative treatment of displaced midshaft clavicular fractures. J Bone Joint Surg Am
. Lazarides S, Zafiropoulos G: Conservative treatment of fractures at the middle third of the clavicle: The relevance of shortening and clinical outcome. J Shoulder Elbow Surg
. Canadian Orthopaedic Trauma Society: Nonoperative treatment compared with plate fixation of displaced midshaft clavicular fractures: A multicenter, randomized clinical trial. J Bone Joint Surg Am
12. Ljunggren AE: Clavicular function. Acta Orthop Scand
. Ludewig PM, Behrens SA, Meyer SM, Spoden SM, Wilson LA: Threedimensional clavicular motion during arm elevation: Reliability and descriptive data. J Orthop Sports Phys Ther
14. Simpson NS, Jupiter JB: Clavicular nonunion and malunion: Evaluation and surgical management. J Am Acad Orthop Surg
15. Fung M, Kato S, Barrance PJ, et al: Scapular and clavicular kinematics during humeral elevations: A study with cadavers. J Shoulder Elbow Surg
16. Stanley D, Trowbridge EA, Norris SH: The mechanism of clavicular fracture: A clinical and biomechanical analysis. J Bone Joint Surg Br
17. Neer CS II: Nonunion of the clavicle. JAMA
18. Allman FL Jr: Fractures and ligamentous injuries of the clavicle and its articulation. J Bone Joint Surg Am
19. Fracture and dislocation compendium: Orthopaedic Trauma Association Committee for Coding and Classification. J Orthop Trauma
1996;10(suppl 1): 1-154.
. Robinson CM, Court-Brown CM, McQueen MM, Wakefield AE: Estimating the risk of nonunion following nonoperative treatment of a clavicular fracture. J Bone Joint Surg Am
21. Eskola A, Vainionpää S, Myllynen P, Pätiälä H, Rokkanen P: Outcome of clavicular fracture in 89 patients. Arch Orthop Trauma Surg
22. Wick M, Müller EJ, Kollig E, Muhr G: Midshaft fractures of the clavicle with a shortening of more than 2 cm predispose to nonunion. Arch Orthop Trauma Surg
23. Nordqvist A, Redlund-Johnell I, von Scheele A, Petersson CJ: Shortening of clavicle after fracture: Incidence and clinical significance, a 5-year followup of 85 patients. Acta Orthop Scand
24. Böstman O, Manninen M, Pihlajamaki H: Complications of plate fixation in fresh displaced midclavicular fractures. J Trauma
25. Hill JM, McGuire MH, Crosby LA: Closed treatment of displaced middlethird fractures of the clavicle gives poor results. J Bone Joint Surg Br
26. Oroko PK, Buchan M, Winkler A, Kelly IG: Does shortening matter after clavicular fractures? Bull Hosp Jt Dis
27. Andersen K, Jensen PO, Lauritzen J: Treatment of clavicular fractures: Figure-of-eight versus a simple sling. Acta Orthop Scand
. Coupe BD, Wimhurst JA, Indar R, Calder DA, Patel AD: A new approach for plate fixation of midshaft clavicular fractures. Injury
. Iannotti MR, Crosby LA, Stafford P, Grayson G, Goulet R: Effects of plate location and selection on the stability of midshaft clavicle osteotomies: A biomechanical study. J Shoulder Elbow Surg
. Kloen P, Sorkin AT, Rubel IF, Helfet DL: Anterioinferior plating of mid shaft clavicular nonunions. J Orthop Trauma
31. Poigenfürst J, Rappold G, Fischer W: Plating of fresh clavicular fractures: Results of 122 operations. Injury
32. Ngarmukos C, Parkpian V, Patradul A: Fixation of fractures of the midshaft of the clavicle with Kirschner wires: Results in 108 patients. J Bone Joint Surg Br
33. Grassi FA, Tajana MS, D'Angelo F: Management of midclavicular fractures: Comparison between nonoperative treatment and open intramedullary fixation in 80 patients. J Trauma
34. Leppilahti J, Jalovaara P: Migration of Kirschner wires following fixation of the clavicle: A report of 2 cases. Acta Orthop Scand
. Jubel A, Andemahr J, Bergmann H, Prokop A, Rehm KE: Elastic stable intramedullary nailing of midclavicular fractures in athletes. Br J Sports Med
. Chu CM, Wang SJ, Lin LC: Fixation of mid-third clavicular fractures with Knowles pins: 78 patients followed for 2-7 years. Acta Orthop Scand
. Verborgt O, Pittoors K, Van Glabbeek F, Declercq G, Nuyts R, Somville J: Plate fixation of middle-third clavicle fractures in the semi-professional athlete. Acta Orthop Belg
38. Wu CC, Shih CH, Chen WJ, Tai CL: Treatment of clavicular aseptic nonunion: Comparison of plating and intramedullary nailing techniques. J Trauma
39. Ali Khan MA, Lucas HK: Plating of fractures of the middle third of the clavicle. Injury
40. Zenni EJ Jr, Krieg JK, Rosen MJ: Open reduction and internal fixation of clavicular fractures. J Bone Joint Surg Am
. Brinker MR, Edwards TB, O'Connor DP: Estimating the risk of nonunion following nonoperative treatment of a clavicular fracture. J Bone Joint Surg Am
42. Manske DJ, Szabo RM: The operative treatment of mid-shaft clavicular non-unions. J Bone Joint Surg Am
43. Jupiter JB, Leffert RD: Non-union of the clavicle: Associated complications and surgical management. J Bone Joint Surg Am
44. Karaharju E, Joukainen J, Peltonen J: Treatment of pseudarthrosis of the clavicle. Injury
45. Boehme D, Curtis RJ Jr, DeHaan JT, Kay SP, Young DC, Rockwood CA Jr: Non-union of fractures of the midshaft of the clavicle: Treatment with a modified Hagie intramedullary pin and autogenous bone-grafting. J Bone Joint Surg Am
46. McKee MD, Wild LM, Schemitsch EH: Midshaft malunions of the clavicle. J Bone Joint Surg Am
. Ledger M, Leeks N, Ackland T, Wang A: Short malunions of the clavicle: An anatomic and functional study. J Shoulder Elbow Surg
48. Basamania CJ: Abstract: “Claviculoplasty” and intramedullary fixation of malunited, shortened clavicle fractures. J Shoulder Elbow Surg
49. Bosch U, Skutek M, Peters G, Tscherne H: Extension osteotomy in malunited clavicular fractures. J Shoulder Elbow Surg
50. Chan KY, Jupiter JB, Leffert RD, Marti R: Clavicle malunion. J Shoulder Elbow Surg