A 13-year-old boy with no pertinent past medical history presents with 3 days of worsening right ring finger pain and swelling. He jammed his finger while playing football 10 days ago. He has been buddy taping his fingers and taking Tylenol; however, he is now having worsening pain and swelling. More recently, he noticed that his finger would not flex or extend at the distal joint. On exam, he has normal vital signs and is otherwise well-appearing. Examination of his right fourth digit reveals erythema just proximal to and surrounding the eponychial fold with underlying hypopigmentation concerning for purulence. He is unable to actively or passively extend at the DIP joint, and it has the appearance of a mallet finger.
What is the diagnosis?
Seymour fracture with paronychia
X-ray reveals a transverse fracture of the metaphysis of the distal phalanx with extension into the physis, with 1-2 mm of distraction of the fracture fragments and 13 degrees of apex dorsal angulation and soft tissue swelling at the level of the nailbed. Thus, the patient has a Salter-Harris II fracture of the right ring finger with concern for overlying nailbed laceration. This is also known as a Seymour fracture.
A Seymour fracture is a displaced fracture of the distal phalanx that involves the physis with an underlying nailbed laceration.1 It is typically thought of as an open fracture and occurs in children and adolescents because of the incomplete closure of the distal phalanx.2 The mallet finger appearance is secondary to the fact that the extensor tendon inserts into the epiphysis of the distal phalanx, and the flexor digitorum profundus tendon inserts into the metaphysis, causing flexion at the distal phalanx.3
Why does this matter? Because of the location of the fracture and overlying nailbed laceration, there is interposed soft tissue present in the actual fracture site. Therefore, operative management is typically required to remove this tissue.2 Once treated in the operating room, these patients often require 5-7 days of antibiotics. Without proper recognition and treatment, this injury can result in nail plate deformity, physeal arrest, and/or chronic osteomyelitis.3
What if this injury occurs in an adult? These injuries are labeled Seymour-type fractures and present with what appears to be mallet finger. They can be managed conservatively or operatively, depending on type of nailbed injury, reduction of fracture site and instability of the fracture.3
- Seymour N. Juxta-epiphyseal fracture of the terminal phalanx of the finger. J Bone Joint Surg Br. 1966;48(2):347-329.
- Abzug J, Kozin H. Seymour fractures. J Hand Surg. 2013;38(A):2267-2270.
- Ugular M, Saka G, Saglam N, Milcan A, Kurtulmus T, Akpinar F. Distal phalanx fracture in adults: Seymour-type fracture. J Hand Surg Eur Vol. 2014;39(3):237-241.
- Krusche-Mandl I, Kottstorfer J, Thalhammer G, Adrian S, Erhart J, Platzer P. Seymour fractures: retrospective analysis and therapeutic considerations. J Hand Surg Am. 2013; 38(2):258-264.