Management of Seymour (Distal Phalangeal) Fractures with Nail Bed Involvement.

BACKGROUND

Seymour fractures are a unique type of pediatric distal phalangeal fracture that can be easily misdiagnosed as a simple nail-bed injury or mallet finger. Because of this potential for misdiagnosis, clear communication with consulting physicians regarding physical examination findings, such as nail plate avulsion and radiographic findings, is necessary. Seymour fractures involve the open physis and the germinal matrix, which become interposed in the fracture site, increasing the likelihood of infection. Open fractures are often displaced as a result of the distracting forces of the extensor and flexor tendons. This displacement, combined with the frequent association of nail bed lacerations, creates a high risk of complications such as infection and nonunion. If left untreated or inadequately treated, these complications can lead to further surgery, prolonged antibiotic use, and potentially long-term impairment of hand function and cosmesis.

DESCRIPTION

The procedure is performed with the patient under local anesthesia and with a glove tourniquet applied at the base of the operative finger. With use of blunt instruments such as a Freer elevator and a hemostat, the nail plate is carefully removed, and an eponychial flap is elevated proximally to expose the germinal matrix and fracture site. The interposed germinal matrix tissue at the fracture site is delicately elevated as a proximally based flap, fully revealing the fracture site for thorough irrigation, debridement, and reduction. Fracture fragments typically achieve anatomical alignment spontaneously upon removal of the interposed germinal matrix tissue. Reduction is verified visually and on fluoroscopy. The germinal matrix flap is meticulously sutured to the nail bed with use of 6-0 or 7-0 absorbable sutures, ensuring proper fracture alignment and correction of the pseudo-mallet deformity. For cases with instability, a 1.2- or 1.0-mm Kirschner wire may be placed retrogradely across the fracture and distal interphalangeal joint for additional stability. To support the repair, the nail plate or a substitute material may be temporarily placed beneath the eponychial fold; however, the nail plate is usually removed to reduce the risk of infection. The eponychial flap is reapproximated with simple interrupted sutures, and the procedure is concluded with the application of sterile, nonadherent dressings. The operative finger is immobilized with use of a below-the-elbow splint. All fracture reductions should be confirmed on postoperative radiographs.

ALTERNATIVES

Alternative nonoperative treatments for Seymour fractures include closed reduction and splinting and/or the use of antibiotics. Alternative operative treatments include open reduction and internal fixation with use of Kirschner wires and nail-bed repair.

RATIONALE

This technique for managing Seymour fractures emphasizes meticulous nail-bed repair and selective Kirschner wire fixation. Unlike splinting alone, which risks malunion and nail deformities, or routine Kirschner wire use, which increases infection and growth disturbance risks, our approach balances achievement of stability with minimization of complications. For open fractures, thorough debridement and antibiotic use are prioritized to prevent infection. In unstable or displaced fractures, Kirschner wire fixation ensures stability when closed reduction is inadequate. Nail-bed repair is essential to prevent deformities and promote optimal healing. This standardized method offers a balanced strategy, ensuring anatomical reduction, stability, and infection risk minimization, particularly in open, unstable, or nail-bed-involved fractures.

EXPECTED OUTCOMES

With proper treatment, most children with Seymour fractures make a full recovery and have no long-term problems. However, it is important to be aware of potential complications, such as infection, nail deformity, or growth disturbance. Research has shown that early treatment of Seymour fractures significantly reduces the risk of complications. A recent study found that early debridement and removal of interposed tissue within 48 hours of injury reduced the risk of infection by 72%. Similarly, early antibiotic use within 24 hours of injury decreased the risk of infection by 79%. When both early debridement and antibiotics were utilized, the risk of infection was reduced by 70%.

IMPORTANT TIPS

Suspect a Seymour fracture in children with a history of crush injury to the fingertip and an open physis.Careful clinical examination is crucial to avoid misdiagnosis as a simple nail-bed injury or mallet finger.Radiographic evaluation is essential to confirm the diagnosis and assess fracture displacement.Achieve a bloodless field with a finger tourniquet to optimize visualization.Meticulous nail-bed repair is critical to prevent nail deformities and promote healing.For cases with instability, a 1.2- or 1.0-mm Kirschner wire may be placed retrogradely across the fracture and distal interphalangeal joint for additional stability.Misdiagnosis or delayed treatment can lead to notable complications and long-term morbidity.Inadequate debridement and irrigation can increase the risk of infection and osteomyelitis.Improper handling of the germinal matrix can cause nail deformity or growth disturbances.Unstable fixation or premature mobilization may result in malunion or nonunion.Identifying and carefully extracting interposed germinal matrix tissue can be technically demanding.Achieving stable fixation of small, displaced fragments can be challenging.Preventing long-term complications such as nail deformity and growth disturbance requires meticulous surgical technique and postoperative care.We monitor healing closely and provide guidance to the patient regarding hand therapy in order to help them regain full finger motion and function.

ACRONYMS AND ABBREVIATIONS

PIP = proximal interphalangealDIP = distal interphalangeal.