Review Article Management of Distal Clavicle Fractures Abstract Rahul Banerjee, MD Most clavicle fractures heal without difficulty. However, radiographic Brian Waterman, MD nonunion after distal clavicle fracture has been reported in 10% to 44% of patients. Type II distal clavicle fractures, which involve Jeff Padalecki, MD displacement, are associated with the highest incidence of William Robertson, MD nonunion. Several studies have questioned the clinical relevance of distal clavicle nonunion, however. Nonsurgical and surgical management provide similar results. The decision whether to operate may be influenced by the amount of fracture displacement and the individual demands of the patient. Surgical options to achieve bony union include transacromial wire fixation, a modified Weaver-Dunn procedure, use of a tension band, screw fixation, plating, and arthroscopy. Each technique has advantages and disadvantages; insufficient evidence exists to demonstrate that any one technique consistently provides the best results. From the Department of ractures of the distal clavicle ac- not only which distal clavicle frac- Orthopaedic Surgery, University of Texas Southwestern Medical Center, Fcount for approximately 10% to tures require surgical fixation but Dallas, TX (Dr. Banerjee, 30% of all clavicle fractures.1 Man- also which fixation method is best. Dr. Padalecki, and Dr. Robertson), agement of distal clavicle fractures is and the Department of Orthopaedic often challenging because of the dif- Surgery and Rehabilitation, Texas Anatomy and Tech University Health Sciences ficulty in distinguishing subtle varia- Center, El Paso, TX (Dr. Waterman). tions in the fracture pattern that may Biomechanics Dr. Banerjee or an immediate family indicate fracture instability. Stable The clavicle serves as a strut connect- member has received research or fracture patterns generally heal un- ing the upper extremity to the appen- institutional support from Synthes, eventfully with nonsurgical manage- Smith & Nephew, Medtronic, and dicular skeleton. Fluid scapulotho- Stryker, and serves as a board ment, but unstable fracture patterns racic motion is dependent on a stable member, owner, officer, or are often associated with longer time relationship between the distal clavi- committee member of the American to union and notable nonunion rates. Academy of Orthopaedic Surgeons. cle and the scapula. This stability is Dr. Robertson serves as a paid Because of concern that nonsurgi- provided by the acromioclavicular consultant to ConMed Linvatec. cal management may result in non- (AC) joint capsule, AC ligaments, Neither of the following authors nor union, primary surgical management and coracoclavicular (CC) ligaments. any immediate family member has has been recommended for certain received anything of value from or The AC ligaments span the AC 2-6 owns stock in a commercial distal clavicle fracture patterns. joint, attaching to both the medial company or institution related However, these nonunions are often aspect of the acromion and the distal directly or indirectly to the subject of asymptomatic, and their clinical rele- extent of the clavicle and reinforcing this article: Dr. Waterman and 1,7 Dr. Padalecki. vance has been questioned. The use the AC joint capsule. These liga- of nonsurgical management is bol- ments serve as an important stabi- J Am Acad Orthop Surg 2011;19: 392-401 stered by the various complications lizer to horizontal (AP) motion at the that have historically been reported AC joint.8 This capsuloligamentous Copyright 2011 by the American following surgical fixation. As a re- Academy of Orthopaedic Surgeons. complex attaches to the distal aspect sult, there is uncertainty regarding of the clavicle approximately 6 mm 392 Journal of the American Academy of Orthopaedic Surgeons Rahul Banerjee, MD, et al 9 medial to the AC joint. Figure 1 The CC ligaments (ie, trapezoid, conoid) originate at the base of the coracoid process of the scapula and insert on the undersurface of the dis- tal clavicle. The trapezoid is the more lateral of the two ligaments and attaches to the distal clavicle approximately 2 cm from the AC joint.9 The conoid ligament, which is located more medially, attaches to the clavicle approximately 4 cm from the AC joint. These ligaments play a pivotal role in preventing superior displacement of the distal clavicle in relation to the acromion. The normal distance between the coracoid pro- cess and the undersurface of the clav- icle (ie, CC interspace) is 1.1 to 1.3 cm.10 The clavicle also serves as an im- portant origin and site of insertion for several muscles involved in mo- tion of the shoulder and the cervical spine, including the sternocleidomas- Illustration of the Neer classification of distal clavicle fractures. Type I fracture occurs distal to the coracoclavicular (CC) ligaments (ie, trapezoid, conoid) toid, anterior deltoid, and trapezius. and involves minimal fracture displacement. The acromioclavicular (AC) joint Depending on the fracture pattern, remains intact. Type IIA fracture occurs medial to the conoid ligament. Type these muscles can create deforming IIB fracture occurs between the CC ligaments and includes disruption of the forces. Neer4 described four deform- conoid ligament. The trapezoid ligament remains intact. Type III fracture occurs distal to the CC ligaments and extends into the AC joint. Type IV ing forces: weight of the arm; pull of fracture occurs in pediatric patients. The physis and epiphysis remain the pectoralis major, pectoralis mi- adjacent to the AC joint, but there is displacement at the junction of the nor, and latissimus dorsi muscles; metaphysis and physis. In type V fracture, a small inferior clavicular fragment scapular rotation; and pull of the tra- remains attached to the CC ligaments. pezius muscle on the proximal frag- ment. these soft-tissue attachments. fragment is detached from the CC Type III fractures are similar to ligaments. The distal fragment re- Classification type I fractures in that they also oc- mains attached to the scapula via the cur distal to the CC ligaments. How- AC joint capsule. In type IIA frac- Neer5,11 and later, Craig,12 classified ever, type III fracture extends into ture, the fracture lies medial to the distal third clavicle fractures into the AC joint. Because the ligamen- conoid ligament. In type IIB fracture, three types based on the relationship tous structures remain intact, type III the fracture lies between the conoid of the fracture line to the CC liga- fractures are relatively stable and and trapezoid ligaments. The rela- ments and AC joint (Figure 1). Type typically are minimally displaced. tionship of the distal fragment to the I fractures occur lateral to the CC Persons with this injury may be at coracoid process may differ between ligaments but spare the AC joint. risk of posttraumatic AC joint ar- types IIA and IIB. The proximal fragment is stabilized thropathy because of the intra- In type IIA fractures, the distal to the coracoid process by the CC articular involvement. fragment remains connected to the ligaments and to the distal fragment Type II fractures are less stable coracoid process by the CC liga- by the deltotrapezial fascia. Type I than type I and III fractures, and ments, which are presumed to be in- fractures often are only minimally they present a treatment challenge. tact. With type IIB fractures, the CC displaced because of the presence of In all type II fractures, the proximal ligaments lie within the zone of in- July 2011, Vol 19, No 7 393 Management of Distal Clavicle Fractures Figure 2 tures were classified as type 3. These occur lateral to a vertical line drawn upward from the center of the cora- coid process. Robinson grouped fractures into subgroups A and B based on displacement of the major fragments. Subtypes A and B were subdivided according to articular in- volvement. This classification was found to have substantial interob- server reliability (mean kappa value = 0.77) and excellent intraobserver reliability (average kappa value = 0.84). Clinical Evaluation Most distal clavicle fractures are the result of a fall onto the distal clavicle Illustration of the Robinson classification of distal clavicle fractures (type 3). or a direct blow to it.1,16 Direct impact Type A, cortical alignment fractures: 1, extra-articular; 2, intra-articular. Type occurs at the acromion, usually with B, displaced fractures: 1, extra-articular; 2, intra-articular. (Redrawn with permission from Robinson CM: Fractures of the clavicle in the adult: the arm in an adducted position, and Epidemiology and classification. J Bone Joint Surg Br 1998;80[3]:476-484.) force is transmitted through the AC joint to the CC ligaments and the dis- tal clavicle. Patients with distal clavicle jury. In Neer type IIB fractures, the taphysis. Depending on the degree of fractures typically present with shoul- conoid ligament is torn, but the trap- displacement, these patients are der pain. Associated injuries should be ezoid is presumed to remain attached treated with closed or open reduc- ruled out, such as other injuries to the to the distal fragment.12 This classifi- tion.14 In type V fracture, only a shoulder girdle, rib fracture, ipsilateral cation was developed before wide- small inferior cortical fragment re- upper extremity injury, and injury to spread use of MRI, and we are un- mains attached to the CC ligaments. the thorax or cervical spine. These are aware of any study that has Type V fractures are functionally particularly likely to occur in conjunc-