Classifications In Brief: The Gartland Classification of Supracondylar Humerus Fractures

History Supracondylar humerus fractures are the most common elbow injury in pediatric patients 24. During the 1950s, these injuries were called the “misunderstood fracture,” as such injuries often resulted in bony deformity and Volkmann's contracture 12. In 1959, Gartland described a simple classification scheme to reemphasize principles underlying treatment of patients with a supracondylar humerus fracture and discussed a method of injury management that has proven to be practical and effective with time 12. Supercondylar humerus fractures occur proximal to the articular surface of the distal humerus and may be transverse, oblique, or jagged. Gartland described a rotatory and translational deformity, with posterior displacement (extension) of the distal fragment occurring most often 12. He described three types of extension injury based on degree of displacement: type I, nondisplaced; type II, moderately displaced; and type III, severely displaced injury, and he considered flexion-type injuries separately 12. Purpose Gartland 12 first described a treatment algorithm to allow widespread management of the common but previously misunderstood supracondylar humerus fracture to decrease the incidence of malunion and Volkmann's contracture. Nondisplaced fractures were to be immobilized in a plaster cast with the forearm flexed 75° to 80° in neutral rotation without manipulative reduction. He emphasized the importance of a detailed neurologic and vascular examination and cautioned against applying a cast that was too tight or flexing the elbow past 80°. For moderate displacement, closed reduction and casting with the patient under general anesthesia was the preferred treatment. If radiographs obtained 24 hours later showed residual or recurrent displacement, the fracture was considered unstable, and ulna-based overhead skeletal traction was indicated. For severely displaced fractures, the same algorithm was used, with Gartland noting an increased number of unstable fractures and neurologic and vascular injuries 12. In 1963, he reported there may be a role for open reduction of displaced, unstable fractures and stabilization with thin stainless steel wires 13. Treatment of pediatric supracondylar humerus fractures has evolved since Gartland's first description 12; however, current treatment recommendations from the American Academy of Orthopaedic Surgeons remain based on the modified Gartland classification 2, 10, 21. Type I injuries are immobilized with a cast for 3 to 4 weeks, with radiographic alignment checked at 1 week. Type IIA injuries can be treated with closed reduction and casting or percutaneous pinning, whereas type IIB injuries should have closed reduction and percutaneous pinning to prevent coronal and/or rotational malalignment. Types III and IV injuries also are treated with closed reduction and percutaneous pinning, as are flexion-type injuries, with possible open reduction and internal fixation if closed reduction is unsuccessful 2. Treatment details, such as the number of pins, medial versus lateral pin placement, requirement to observe and protect the ulnar nerve with medial pin placement, and construct biomechanical stability have been discussed 2. Open reduction—lateral, medial, or anterior approach—is indicated for an open fracture when irrigation and débridement are needed, when a closed reduction is unsuccessful, and for treatment of fractures associated with a dysvascular limb (pulseless, not pink hand) 21. Traction suspension 12 rarely is used in modern medicine and is reserved for cases where anesthetic is unavailable or patient comorbidities make its use unsafe, when no qualified surgeon is available to perform the procedure, or as a temporizing measure as soft tissue swelling resolves 21. Gartland highlighted Volkmann's contracture—now known to be a complication of untreated compartment syndrome of the forearm—as one of the reasons for physician trepidation when treating supracondylar humerus fractures 12. Guidelines for prompt treatment of these fractures, increased vigilance for detection of the clinical and physiologic manifestations of compartment syndrome, and adequate emergent fasciotomies have decreased rates of contracture; but compartmental syndrome still develops in 0.1% to 0.3% of patients with a sypracondylar humerus fracture 5. Compartment syndrome is more likely to occur as the energy of injury and degree of fracture displacement increase, but it can occur with all Gartland fracture patterns 20, 21. Description of the Gartland Classification Gartland extension type I injuries generally are nondisplaced transverse fractures. Generalized swelling about the elbow could be present; however, no evidence of nerve or vascular compromise is expected. Extension type II fractures originally were described as “moderately posteriorly displaced”, rotated and often requiring reduction 12. Extension (type III) fractures often have oblique patterns with severe displacement and rotation. As the displacement increased, so too did the risk of neurologic or vascular injury 12, 18. In 1982, Abraham et al. 1 created supracondylar humerus fractures in monkey cadavers by loading the extremity and then analyzing the periosteal injury per each Gartland extension-type injury. In type I injuries, the anterior periosteum was found to be intact but detached from the anterior surface of the humerus by up to 3 cm, whereas types II and III injuries had a torn anterior periosteum but an intact posterior hinge that reduced with load removal and fracture reduction 1. Wilkins 22 modified the Gartland classification to make it more clinically relevant, including the concept of posterior humeral cortical contact. Extension type I injuries were nondisplaced; type II injuries were displaced anteriorly (anterior humeral line anterior to capitellum Fig. 1) but had posterior humeral cortical contact; and type III fractures were displaced with no cortical contact. Wilkins also subdivided type II injuries into IIA and IIB categories: IIA fractures have no rotational abnormality or fragment translation, and IIB injuries do, resulting in more instability 22.Fig. 1: The anterior humeral line should cross the capitellum on a true lateral view of an uninjured elbow.In 1995, De Boeck et al. 10 described a subtype of supracondylar humerus fracture where the medial column of the humerus is comminuted and unstable, leading to loss of Baumann's angle (Fig. 2) and the recommendation for closed reduction with percutaneous pinning. In 2006, Leitch et al. 16 suggested the addition of a type IV injury believed to be difficult to treat owing to multiplanar instability, identified intraoperatively, from no intact periosteal hinge 16 (Fig. 3; Table 1).Fig. 2: Baumann's angle is a radiographic angle created by the intersection of a line drawn down the humeral axis (A) and a line drawn along the physis (B) of the lateral condyle of the elbow on the AP view of the elbow (normal range, 9°-26°) 24. α = angle.Fig. 3A-C: Lateral radiographs are shown for Gartland (A) type I, (B) type II, and (C) type III supracondylar humerus fractures.Table 1: Modified Gartland classification of supracondylar humerus fractures 10 , 21Reliability Barton et al. 4 evaluated the reliability of the modified Gartland classification, using a version modified by Wilkins et al. in 1996 23, which included three types of fracture based on the amount of displacement and posterior cortical hinge. Type IV and the medial column comminution subtypes had not yet been added at the time of their work. Barton et al. 4 used five different reviewers of 50 extension-type supracondylar humerus fractures at three different times. They found after a 2-week interval that 90% of the fractures were classified the same way with an intraobserver kappa value of 0.84. At 3 years, review of the same radiographs led to 89% of fractures being likewise classified, with a kappa value of 0.81. Most disagreement was encountered when differentiating type I from type II injuries, which is concerning because the indicated treatment for type I injuries is casting, while closed reduction and percutaneous pinning are suggested for type II injuries 5. At least three of five reviewers agreed on the classification of all 50 cases at all three times. Interobserver reliability was determined to be 0.74 4. De Gheldere et al. 11 evaluated the reliability of the Lagrange and Rigault classification with 100 supracondylar humerus fractures and five different observers on two separate occasions. They found intraobserver reliability to be 0.76 and interobserver reliability was 0.69, similar to data for the Gartland classification 11. Limitations While the Gartland classification does not specifically incorporate neurovascular compromise, vascular injury has been found to occur almost exclusively in extension type III or higher supracondylar humerus fractures 17, and these injuries were not considered in Gartland's classification. The brachial artery can be occluded, in spasm, entrapped, severed, or tethered by the proximal fragment of the supracondylar fracture before or after reduction. It was reported that the radial pulse is absent on initial presentation in 7% to 12% of patients with supracondylar fractures 14, but an occluded or tethered artery may recover with adequate fracture reduction 15 with the incidence of impaired circulation after an adequate fraction reduction less than 0.8% 8, 14. Decisions to explore the brachial artery surgically are based on extremity perfusion, not the presence or absence of a pulse 21. Gartland also recognized that nerve injuries often were associated with supracondylar humerus fractures 12, but these were not addressed in his classification. It now is known that nerve injuries are the most frequent complication associated with such fractures, occurring in 11.3% of cases 3. Primary nerve injuries are believed to result from tenting of the nerve on the sharp proximal fragment or entrapment of the nerve in the fracture site 19. Gartland noted that most nerve injuries were transient and recommended initial treatment as if no nerve damage was present 12. Several studies have supported this, with 86% to 100% of nerve injuries reported to be neurapraxias, which spontaneously resolve 6, 7, 9, 19. The fracture pattern described by Gartland correlates with the pattern of nerve injury 12. Extension-type fractures, which are the most common, put the anterior interosseous nerve at greatest risk of injury 3. Of extension-type fractures, traumatic neurapaxia occurred with a weighted event rate of 11.3%, affecting the anterior interosseous nerve in 34.1% of traumatic neurapraxias 3. Less common flexion-type fractures are associated with a weighted event rate of neurapraxia of 16.6%, affecting the ulnar nerve in 91.3% of cases 3. Conclusions The Gartland classification is a commonly used system for evaluation and treatment of supracondylar humerus fractures in children. It has good interobserver and intraobserver reliability and Type III injuries are commonly associated with neurovascular injuries, where there should be heightened awareness. Gartland recognized the major complications associated with supracondylar humerus fractures and his work remains the foundation for modern treatment of these injuries.