Hand injuries are the most common injuries in pediatric and adolescent populations, with the phalanges being the most frequently injured bones in the hand.1,2 The physis is located at the proximal end of the phalanges; however, there can be a secondary ossification center distally at the level of the phalangeal neck. The central slip of the extensor tendon attaches at the dorsal epiphysis of the middle phalanx, whereas the terminal extensor tendon attaches at the dorsal epiphysis of the distal phalanx. By contrast, the flexor tendons attach distal to the physis on the volar aspect of the phalanges. The purpose of this article was to pass on what is hoped to be useful advice to community orthopaedic surgeons who deal with pediatric phalangeal fractures through the normal course of taking call.
It is important to be diligent when examining children with a suspected phalangeal fracture. The examination should begin with observation, especially in young children, as substantial information can be obtained. For example, the skin should be assessed for abrasions, ecchymosis, and swelling. The nail complex should be examined for subungual hematoma, eschar at the base, or nail plate damage. One can also assess the color of the skin for vascularity and the turgor of the skin. Dry, cracking skin, particularly on 1 side of a digit, is indicative of a nerve injury, as the nerves provide moisture to the skin. Assessment of this has been termed “the sweat test” which permits the examiner to feel for the presence or absence of moisture on the skin. Observation, particularly in young children, can also permit for the assessment of the integrity of the tendons, as well as to see if there is any obvious coronal or sagittal plane deformity or malrotation. Assessment of the digital cascade, including comparison to the contralateral hand, is important when assessing alignment. This may be best accomplished by assessing the tenodesis effect. Using this technique allows for assessment of malrotation, substantial deviation, and the integrity of the tendons (see Video 1, Supplemental Digital Content 1, http://links.lww.com/JOT/A174).
Palpation should occur beginning from the shoulder and working toward the fingers to ensure that there are no other areas of tenderness. In older children, aged 6 years and older, digital sensation can be assessed using static/moving 2-point discrimination. When a nerve injury is suspected in younger children, one can assess for the presence of wrinkles after the placement of the hand in warm water for 10 minutes, termed “the wrinkle test.” Plain radiographs, posteroanterior and lateral views of the injured finger, are typically sufficient to diagnose pediatric phalangeal fractures. Oblique views can be beneficial if an articular fracture is suspected. Hand radiographs can be obtained in patients with injuries to multiple digits.
Distal Tuft Fractures
Distal tuft fractures commonly occur in very young children as they explore. Therefore, these injuries often occur at home because of a crush injury, such as in a door. The soft tissue including the pulp and nail bed may sustain a laceration or have substantial ecchymosis. Most distal tuft fractures are closed injuries and can be treated with a mitten cast or the use of a splint, such as a clam shell or cap splint, for approximately 2 to 3 weeks. Surgical intervention is warranted in open injuries and near amputations to perform an irrigation and debridement and stabilize the fracture, which can typically be accomplished just by suturing the skin.
Seymour fractures are unique injuries to the pediatric population. These injuries involve a juxta-epiphyseal fracture of the distal phalanx with a concomitant nail bed laceration, thus making them an open fracture.3 The nail bed laceration is not always visible, but one can recognize the injury because of the nail plate lying superficial to the eponychial fold, thus giving the appearance of the nail plate of the injured digit being longer than the adjacent nail plates (Fig. 1). Often, there is also eschar present at the level of the eponychial fold by the time the patient is seen in the outpatient setting. An additional clue to the diagnosis of a Seymour fracture is noting that the distal phalanx is resting in a flexed posture. This occurs because there is an imbalance between the terminal extensor tendon, which inserts on the dorsal epiphysis, and the flexor digitorum profundus tendon, which inserts on the volar metaphysis. While some may think this is a mallet finger (bony or soft tissue), that is not accurate as the displacement in a Seymour fracture occurs at the level of the physis, where the fracture is, as opposed to the distal interphalangeal (DIP) joint (Fig. 2).
Surgical intervention is often used to treat these fractures, either in the emergency department or the operating room. After appropriate anesthesia, a tourniquet is placed either on the digit or the arm. The nail plate is removed using blunt instrumentation, such as a freer elevator and hemostat, thus exposing the nail bed. However, as the laceration is often at the level of the germinal matrix, it may still not be visible after nail plate removal. Therefore, small oblique incisions, directed proximally toward the DIP joint at the junction of the paronychial and eponychial folds, are made, and the eponychial fold is reflected in a proximal direction. Hyperflexion of the digit will permit visualization into the fracture site, and a gentle irrigation and debridement can be performed (Fig. 3). It is imperative to ensure that there is no interposition of soft tissue, such as periosteum or nail matrix, when the fracture is reduced. Failure to remove the soft tissue can prevent an anatomic reduction, lead to physeal arrest, and/or lead to nail plate irregularity. Once the fracture is reduced, it can be stabilized by suturing the soft tissues and/or placing a retrograde Kirschner wire across the DIP joint. The nail plate is now replaced beneath the eponychial fold (Fig. 4). Failure to recognize a Seymour fracture and appropriately manage it can result in substantial complications, including infection and/or osteomyelitis, physeal arrest, and/or nail plate deformity.3
Bony Mallet Fractures
A bony mallet fracture involves a fracture of the distal phalanx, which has the terminal extensor tendon attached to it. The fracture fragment may be a small piece of the epiphysis (Salter–Harris Type III) or may be a larger fragment that includes the metaphysis (Salter–Harris Type IV). These fractures follow the adult principles for treatment which attempt to prevent an extensor lag, achieve adequate joint stability, and ensure that a swan-neck deformity does not occur. Therefore, those injuries that involve less than 1/3 of the articular surface and do not have joint subluxation can be treated in full extension with either cast or splint immobilization full time for 6–8 weeks. Night-time splinting in extension should be used for an additional 2–4 weeks. Surgical management is indicated when there is joint subluxation, the fracture fragment encompasses more than 1/3 of the articular surface, or there is a lack of cortical bony contact after an attempted reduction with splinting. The surgical technique most commonly used to treat these fractures is extension block pinning, which permits an indirect reduction of the fracture without the need to open the fracture site4 (Fig. 5).
Phalangeal condyle fractures are articular fractures that can include a unicondylar fracture, a bicondylar fracture, a lateral avulsion fracture, or a subcondylar shear fracture, with or without an associated joint subluxation/dislocation. These fractures can be difficult to treat, as delayed presentation is common and the injuries may be difficult to identify on plain radiographs, especially because the posteroanterior view may appear normal. Lateral and oblique views are very helpful when identifying these injuries, particularly looking for a double-density sign, indicating displaced offset of one condyle compared with the other.
Optimal treatment of the fracture is with closed methods to preserve the blood supply of the small fracture fragment.5 Therefore, reduction of the fracture should be achieved with the assistance of a towel clamp or the use of a Kirschner wire as a joystick. Once the fragment is reduced, Kirschner wires can be placed percutaneously to stabilize the fracture. Open reduction is reserved unless it is absolutely necessary. If an open reduction is performed, it is imperative to preserve the collateral ligament, as this is where the blood supply of the condyles comes from (Fig. 6).
Phalangeal Neck Fractures
Phalangeal neck fractures are fractures that occur distal to the collateral ligament recess but do not involve the articular surface. Most commonly, these fractures have an apex volar angulation with associated sagittal and subcondylar malalignment. Furthermore, the adjacent interphalangeal joint hyperextends, and the distal bony spike of the volar cortex of the proximal fragment impedes flexion. Therefore, these fractures typically require operative fixation if they are displaced.
It is important to obtain a true lateral radiograph of the injured digit to assess the amount of dorsal displacement. Ultimately, the subcondylar recess must be maintained to ensure that full flexion of the digit is obtainable. Therefore, nondisplaced and minimally displaced fractures must be followed very closely to ensure this. As it is not really possible to visualize the alignment adequately in a cast due to overlap of the adjacent digits, the cast must be removed and dedicated radiographs of the injured digit must be obtained.
Surgical management of these fractures is typically with closed reduction and percutaneous pinning techniques (Fig. 7). Hyperflexion of the adjacent interphalangeal joint aids in reduction of the fracture. A Kirschner wire can then be placed retrograde across the fracture and then brought out the dorsal skin, while maintaining fixation across the fracture site. Subsequently, the adjacent IP joint can be extended and the wire can be advanced antegrade to exit out the tip of the finger. If closed reduction is not possible, one can proceed to a percutaneous reduction using a temporary intrafocal Kirschner wire as a joystick, with an osteoclasis performed as necessary. Open reduction is reserved as a last resort, as this increases complications including avascular necrosis and stiffness.6
Limited remodeling occurs in the sagittal plane in these fractures because of distance from the physis, and almost no remodeling occurs in the coronal plane.7 Therefore, near anatomic alignment is necessary when treating these fractures. Malunions can be treated using osteotomy (uniplanar or biplanar) or by recreation of the volar concavity of the subcondylar recess; however, these procedures have high complication rates.
Phalangeal Shaft Fractures
Phalangeal shaft fractures are less common in the pediatric population, as the physis is the biomechanically weakest location, and therefore, most fractures occur about the physis. It is crucial to assess the digital cascade in these injuries, as subtle fractures can have associated rotational or angular deformity present.
Minimally displaced and nondisplaced fractures can be managed with buddy taping with or without the use of a splint, followed by early active range of motion. An exception is fractures that are spiral or vertically oblique, as these fracture patterns are inherently unstable, and therefore, more rigid immobilization for 3–4 weeks is necessary. Displaced fractures, particularly spiral and vertically oblique fracture patterns, often require surgical stabilization, typically using Kirschner wires.
Phalangeal Base and Salter–Harris Fractures
Salter–Harris type II fractures of the proximal phalanx are the most common type of finger fracture. These fractures can commonly result in coronal plane deviation, even if the fracture appears relatively benign on the radiographs. Minor deviation in a young child will worsen as the child grows. Salter–Harris type III fractures are more common in the adolescent population, as they approach skeletal maturity.
Treatment of phalangeal base and Salter–Harris fractures is typically immobilization alone, assuming that there is no coronal plane malalignment or rotational deformity. Unstable fractures or those with malalignment can typically be treated with closed reduction and percutaneous pinning. Open reduction is rarely necessary but should be performed if there is soft tissue interposition in the fracture site (flexor tendon) or if severe comminution is present.
Skier/gamekeeper thumb is different in children as compared to adults. Because of the biomechanical weakness of the physis, instead of a pure ligamentous injury, children and adolescents often sustain a Salter–Harris type III fracture of the proximal phalanx, which has the ulnar collateral ligament attached to it. Therefore, in children who have substantial displacement, reduction and fixation of the fragment is necessary to restore stability to the thumb.
Pediatric phalangeal fractures are common injuries. A diligent physical examination and assessment of adequate plain radiographs will lead to the correct diagnosis. Although the majority of these fractures can be treated with immobilization alone, it is important to recognize the fractures that are optimally treated with surgical intervention.
TOP 5 PEARLS
- Assess alignment using direct visualization and the tenodesis effect.
- Assess for concomitant nerve injuries using visualization, the sweat test, and/or the wrinkle test.
- Assess for concomitant tendon injuries using the tenodesis effect and/or the squeeze test.
- Fractures with an eschar at the base of the nail are likely Seymour fractures.
- Fractures about the thumb proximal phalanx with associated laxity need to be stabilized.
TOP 5 PITFALLS
- Beware of mallet fractures with subluxation of the joint.
- Phalangeal neck fractures have minimal remodeling in the coronal plane and only some remodeling in the sagittal plane.
- Do not mistake a Seymour fracture for a minor injury.
- Avoid opening unicondylar fractures if at all possible.
- Avoid accepting an oblique radiograph instead of a true lateral.
1. Naranje SM, Erali RA, Warner WC, et al. Epidemiology of pediatric fractures presenting to emergency departments in the United States. J Pediatr Orthop. 2016;36:e45–e48.
2. Abzug JM, Dua K, Bauer AS, et al. Pediatric phalanx fractures. J Am Acad Orthop Surg. 2016;24:e174–e183.
3. Abzug JM, Kozin SH. Seymour fractures. J Hand Surg Am. 2013;38:2267–2270.
4. Reddy M, Ho CA. Comparison of percutaneous reduction and pin fixation in acute and chronic pediatric mallet fractures. J Pediatr Orthop. 2016 [epub ahead of print].
5. Yousif NJ, Cunningham MW, Sanger JR, et al. The vascular supply to the proximal interphalangeal joint. J Hand Surg Am. 1985;10:852–861.
6. Matzon JL, Cornwall R. A stepwise algorithm for surgical treatment of type II displaced pediatric phalangeal neck fractures. J Hand Surg Am. 2014;39:467–473.
7. Puckett BN, Gaston RG, Peljovich AE, et al. Remodeling potential of phalangeal distal condylar malunions in children. J Hand Surg Am. 2012;37:34–41.