42 Complications of Pediatric Supracondylar Humeral Fractures Carissa L. Meyer, MD Scott H. Kozin, MD Martin J. Herman, MD Shannon Safi er, MD Joshua M. Abzug, MD Abstract and occur equally in boys and girls. The Supracondylar humeral fractures are common in the pediatric population and can result usual mechanism of injury is a fall onto in complications caused by both the injury itself and surgical or nonsurgical treatment. an outstretched hand.4,5 Neurologic complications are frequent, with the anterior interosseous nerve being the most The Gartland classifi cation is the common nerve affected. Vascular injuries, although less common, can result in long-term most widely used classifi cation system sequelae and should be recognized and treated promptly. Loss of reduction can occur with for describing extension-type, supra- both surgical and nonsurgical treatment. Compartment syndrome and infection, although condylar humeral fractures, which rare, require rapid recognition and treatment. It is important to be familiar with the account for 97% to 99% of supracon- potential complications surrounding the treatment of pediatric supracondylar humeral dylar humeral fractures.3 In the original fractures to maximize outcomes and know when a referral may be warranted. classifi cation scheme, type I fractures Instr Course Lect 2015;64:483–491. were considered nondisplaced, type II fractures had an intact posterior hinge, and type III fractures were completely Supracondylar humeral fractures are commonly in children aged 5 to 7 years displaced.6 Wilkins7 modifi ed this clas- common in the pediatric population but have been reported to occur in chil- sifi cation, subdividing type II fractures and account for 3% of all pediatric dren aged 1 to 16 years.3 Fractures most into type IIA and type IIB to aid in fractures.1,2 These fractures occur most often occur on the nondominant side determining the presence of stability with closed reduction and casting alone Dr. Kozin or an immediate family member serves as a paid consultant to or is an employee of Checkpoint Surgical and serves versus closed reduction and percutane- as a board member, owner, offi cer, or committee member of the American Society for Surgery of the Hand. Dr. Herman ous pin fi xation (Table 1). or an immediate family member serves as a board member, owner, offi cer, or committee member of the American Academy of Orthopaedic Surgeons and the Pediatric Orthopaedic Society of North America. Dr. Safi er or an immediate family Most supracondylar humeral frac- member is a member of a speakers’ bureau or has made paid presentations on behalf of Orthopediatrics and serves as a tures can be treated with splinting and paid consultant to or is an employee of Orthopediatrics and Medicrea. Dr. Abzug or an immediate family member serves casting, closed reduction and casting, as a paid consultant to or is an employee of Axogen. Neither Dr. Meyer nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly or closed reduction and percutaneous to the subject of this chapter. pin fi xation. Open reduction is rarely © 2015 AAOS Instructional Course Lectures, Volume 64 483 Pediatrics Table 1 Bloom et al14 performed biome- Modifi ed Gartland chanical testing on various pin con- Classifi cation fi gurations for both well-reduced and slightly malreduced fracture patterns. Type Description Several planes of motion were tested, I Nondisplaced but there was no difference between IIA Intact posterior hinge, no rotational deformity crossed pins or the lateral pin confi gu- IIB Intact posterior hinge, with rations. However, adding a third pin in rotational deformity or either confi guration improved stability, translation The authors believed that slight internal III Complete displacement, no posterior hinge rotation of the distal fragment is com- Figure 1 Lateral (A) and AP (B) monly accepted during pinning, which IV Unstable in both fl exion and illustrations of an ideal pin confi g- extension uration, with the pins maximally may lead to more internal rotation and separated at the fracture site and varus deformity during healing. Most both pins engaging cortices distal importantly, Bloom et al14 noted that and proximal to the fracture (bicor- necessary, but indications for open re- tical fi xation). (Courtesy of Dan A. distal fragment malrotation leads to a duction include a failure to achieve Zlotolow, MD, Philadelphia, PA.) less stable fracture after pinning in any reduction because of an unstable frac- confi guration. Obtaining anatomic re- ture pattern or soft-tissue interposition, duction in the axial plane maximized open fractures, or a vascular injury ne- II fractures surgically, whereas nonsur- stability in all pin confi gurations; there- cessitating open repair. gical management is reserved for very fore, the acceptance of any intraopera- Gartland type I fractures are almost young patients and those with minimal tive malalignment should be avoided. universally treated nonsurgically and extension and no rotational deformity. have excellent outcomes. Cast immo- The location of pin placement for Neurologic Complications bilization for 3 to 4 weeks in 90° of supracondylar humeral fractures also The incidence of nerve injury after a su- fl exion and neutral forearm rotation remains somewhat controversial. Op- pracondylar humeral fracture is reported is adequate. In contrast, Gartland tions include placing two or three lateral to range from 6% to 16%, including type III fractures are almost univer- pins alone or using a cross-pin confi gu- nerve injuries caused by the fracture it- sally treated surgically with closed re- ration. Although two crossed pins were self and iatrogenic injuries that primarily duction and percutaneous pinning. The initially advocated for more unstable result from pin placement.15-17 Typical- expectant outcomes are excellent, but fractures, several studies recently have ly, injuries that occur as a result of the several complications can occur. Sub- found no biomechanical advantage for fracture itself are caused by traction. stantial controversy exists regarding two crossed pins versus two lat eral Patients usually recover between 2 and the treatment of type II fractures, with pins,9-11 whereas other authors have 2.5 months after the fracture; however, some authors recommending surgical found greater rotational stability with recovery can take up to 6 months.15,16,18,19 treatment of all type II fractures, others two crossed pins compared with lateral Although all nerves around the recommending nonsurgical treatment, pins.12,13 elbow have been documented to sus- and some determining treatment based If only two lateral pins are used, the tain an injury, the anterior interosse- on the presence or the absence of rota- pins should be placed in a bicortical ous nerve (AIN) is most commonly tion, based on the Wilkins subclassifi - fashion and diverge at the fracture site involved in extension-type fractures20 cation.1,3,7,8 Surgical intervention for all (Figure 1). The addition of a medial pin (Figure 2). In fl exion-type fractures, type II fractures limits the potential for is advocated in cases of medial cortex the ulnar nerve is most commonly loss of reduction and is less intensive comminution or if the fracture remains injured. In a review of 622 fractures, regarding the necessary follow-up than unstable, as noted with live fl uoroscopy, Bashyal et al21 reported neurologic defi - exists with nonsurgical care. This chap- after the placement of lateral pins. cits in 11.9% of cases, with the AIN ter’s authors prefer to treat most type most commonly affected, followed by 484 © 2015 AAOS Instructional Course Lectures, Volume 64 Complications of Pediatric Supracondylar Humeral Fractures Chapter 42 laxity exhibited ultrasound evidence of ulnar nerve subluxation. This ap- pears to be more common in children younger than 5 years, and the incidence decreases as children age. Skaggs et al10 reported that medial pinning at 90° or less led to a 4% risk of ulnar nerve injury, whereas hyper- fl exion during medial pinning increased that risk to 15%, which was caused by the nerve becoming more anterior with elbow fl exion. The authors rec- ommended lateral pin placement fi rst to Figure 2 Clinical photographs of the hand of a child with an anterior interos- allow for more elbow extension during seous nerve palsy after an extension type supracondylar fracture. Note the medial pinning. lack of thumb interphalangeal fl exion (A) and distal interphalangeal fl exion When it becomes necessary to place of the index fi nger (B). Asking the child to make an “OK” sign can aid in the diagnosis. (Courtesy of Joshua M. Abzug, MD, Baltimore, MD.) a medial pin, multiple authors have ad- vocated making a small incision before pin placement.26-28 This incision permits the radial, median, and ulnar nerves. did not fi nd an increased rate of ulnar placement of the pin directly on the Only the ulnar nerve was affected in nerve palsy with medial pin placement. bone, thus ensuring that the pin does their series of fl exion-type injuries. It is unclear from their evaluations how not go through the bone. Alternatively, Dormans et al22 studied acute type many postoperative palsies were caused recent research has shown that the pre- III extension injuries and found a neu- by iatrogenic nerve injury versus sec- operative use of electrical stimulation rologic injury rate of 9.5%, including ondary differences in documentation twitch monitoring can help map the seven AIN injuries, four median nerve among providers. path of the ulnar nerve and avoid entry injuries, fi ve radial nerve injuries, and Rasool24 reported on six cases of into the cubital tunnel during pinning.29 three ulnar nerve injuries. Each injury ulnar nerve injury from medial pin was treated expectantly, except for one placement, which represented 5% of Vascular Injuries median nerve injury that accompanied all the supracondylar humeral frac- Vascular injury requiring intervention a brachial artery injury.