Bony Complications Caused by Stack Splints

Abstract

Graham Stack designed a splint for the treatment of soft tissue mallet fingers that bears his name.1Stack H.G. A modified splint for mallet finger.J Hand Surg Br. 1986; 11: 163Crossref PubMed Scopus (89) Google Scholar Because it is prefabricated and easy to apply, this splint is often used to immobilize and protect the end of a finger but in situations for which the splint was not designed. Injudicious use can lead to complications, especially in situations in which there has been bony injury.Patient #1: A 16-year-old boy injured his right little finger playing rugby. He had a nondisplaced fracture of the dorsal lip of the distal phalanx base (Fig. 1A). He was placed in a Stack splint and returned 4 weeks later. New radiographs (Fig. 1B) showed displacement of the fracture and volar subluxation of the distal phalanx. He declined further treatment so that he could continue playing rugby.Patient #2: A 70-year-old woman closed a door on her thumb. She had a nondisplaced fracture of the diaphysis of the distal phalanx (Fig. 1C). She was placed in a Stack splint. Three weeks later, she had apex palmar angulation at the fracture site (Fig. 1D). She was pain free and was not totally pleased with the altered appearance of her thumb but declined further treatment.Rupture of the terminal tendon (soft tissue mallet finger) is generally an isolated event. Splinting in extension or neutral allows healing of the tendon. The distal interphalangeal joint is a bicondylar joint with additional stability provided by the collateral ligaments. In a soft tissue mallet injury, the intact dorsal rim provides a buttress to resist the palmar pressure produced by the 3-point fixation of the Stack splint. With a mallet fracture, that buttress is absent and the splint can cause palmar subluxation when it was not present owing to the initial injury.Similarly, a nondisplaced distal phalangeal fracture can be treated with splint immobilization in neutral position. By design, the Stack splint exerts an extension force, and in this setting, that force is transmitted through the fracture causing angulation.When used with care, the Stack splint can be useful for treating soft tissue mallet injuries. However, indiscriminant use can lead to complications, especially when used in situations for which it was not originally designed. Graham Stack designed a splint for the treatment of soft tissue mallet fingers that bears his name.1Stack H.G. A modified splint for mallet finger.J Hand Surg Br. 1986; 11: 163Crossref PubMed Scopus (89) Google Scholar Because it is prefabricated and easy to apply, this splint is often used to immobilize and protect the end of a finger but in situations for which the splint was not designed. Injudicious use can lead to complications, especially in situations in which there has been bony injury. Patient #1: A 16-year-old boy injured his right little finger playing rugby. He had a nondisplaced fracture of the dorsal lip of the distal phalanx base (Fig. 1A). He was placed in a Stack splint and returned 4 weeks later. New radiographs (Fig. 1B) showed displacement of the fracture and volar subluxation of the distal phalanx. He declined further treatment so that he could continue playing rugby. Patient #2: A 70-year-old woman closed a door on her thumb. She had a nondisplaced fracture of the diaphysis of the distal phalanx (Fig. 1C). She was placed in a Stack splint. Three weeks later, she had apex palmar angulation at the fracture site (Fig. 1D). She was pain free and was not totally pleased with the altered appearance of her thumb but declined further treatment. Rupture of the terminal tendon (soft tissue mallet finger) is generally an isolated event. Splinting in extension or neutral allows healing of the tendon. The distal interphalangeal joint is a bicondylar joint with additional stability provided by the collateral ligaments. In a soft tissue mallet injury, the intact dorsal rim provides a buttress to resist the palmar pressure produced by the 3-point fixation of the Stack splint. With a mallet fracture, that buttress is absent and the splint can cause palmar subluxation when it was not present owing to the initial injury. Similarly, a nondisplaced distal phalangeal fracture can be treated with splint immobilization in neutral position. By design, the Stack splint exerts an extension force, and in this setting, that force is transmitted through the fracture causing angulation. When used with care, the Stack splint can be useful for treating soft tissue mallet injuries. However, indiscriminant use can lead to complications, especially when used in situations for which it was not originally designed.