Article, Orthopedics

The Kleinert modified dorsal finger splint for mallet finger fracture

Clinical Notes

The Kleinert modified dorsal finger splint for mallet finger fracture

Raymond G. Hart MD, MPHa,b,*, Harold E. Kleinert MDc,d, Kathleen Lyons RNe

aDepartment of Emergency Medicine, University of Louisville School of Medicine, Louisville, KY 40202, USA

bhand injury Prevention and Research, Christine M. Kleinert Institute for Hand and Microsurgery, Louisville, KY 40202, USA

cKleinert, Kutz and Associates Hand Care Center, Louisville, KY 40202, USA

dDepartment of Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA

eChristine M. Kleinert Institute for Hand and Microsurgery, Louisville, KY 40202, USA

Received 10 May 2004; accepted 10 May 2004

Abstract Injuries to the hand and digits are commonly seen in the emergency department. Lacerations, contusions, puncture wounds, and fractures comprise the bulk of these injuries. A fracture to the dorsum of the distal phalanx can result in a mallet finger deformity. These fractures must be accurately diagnosed with the proper initial treatment begun. There is some disagreement over the best treatment approach and multiple different splints have been described in the literature. Conservative treatment with a finger splint is most commonly effective. We recommend a modified dorsal finger splint for these injuries. We describe a splint to properly treat the fracture, prevent complications, maximize patient comfort during rehabilitation, and prevent mallet finger deformity.

D 2005

Introduction

A mallet finger results from a traumatic disruption of the extensor tendon at the distal interphalangeal (DIP) joint. This can result from an avulsion fracture of the distal phalanx, a disruption of the extensor insertion, or a tear of the extensor tendon. After the disruption has occurred, there is loss of active extension of the distal phalanx. Flexion is unopposed by extensor forces and, if untreated, the distal phalanx will gradually assume a fixed flexed position.

* Corresponding author. Hand Injury Prevention and Research, Christine M. Kleinert Institute for Hand and Microsurgery, Louisville, KY 40202, USA. Tel.: +1 502 562 0310; fax: +1 502 561 4288.

E-mail address: [email protected] (R.G. Hart).

The mechanism of injury is generally an axial load that causes sudden, forced flexion of the distal phalanx. The patient usually presents acutely with a painful, swollen fingertip that is noticeably tender and swollen at the dorsal DIP joint. The distal phalanx will not extend against resistance and will usually assume a subtly more pro- nounced flexed position. A radiograph will most commonly reveal an avulsion fracture at the DIP of the dorsal distal phalanx (Photograph 1).

The treatment of acute mallet finger is splinting [1-5]. There have been many creative splints described in the literature [6-12]. The DIP joint is splinted in 58 to 158 of slight hyperextension. No other digit or joint needs to be included in the splinting acutely; however, if a compensa- tory swan neck deformity occurs, the proximal interphalan- geal (PIP) joint will be included. The splint should remain in

0735-6757/$ – see front matter D 2005 doi:10.1016/j.ajem.2004.05.005

146

Photograph 1 Radiograph–lateral view.

place for 8 weeks. It is important that the patient does not flex the DIP joint during this period of rehabilitation for fear of poor healing and further damage to the extensor insertion. The preferred splint is commonly either a commercially available splint (stack splint) or an aluminum-foam (bZimmer Q) splint. The aluminum foam splint may be applied to either the dorsal or the volar surface.

Some of these cases may present days and weeks after the acute injury. After the pain and swelling resolves, the pa- tient will more likely notice the dysfunctional joint, and the mallet finger deformity becomes apparent (Photograph 2). The distal phalanx may sublux volarly, and the mallet finger

Photograph 2 Mallet finger.

R.G. Hart et al.

Photograph 3 Swan neck deformity.

deformity may progress to a compensatory swan-neck deformity (Photograph 3).

All cases initially evaluated in the emergency department (ED) are safest referred for follow-up to a hand or Orthopedic surgeon. Surgical pinning may be needed in cases where greater than one third of the DIP joint is involved, the joint is unstable, or in those refractory to splinting.

Methods

Our preferred and recommended splint for these injuries is a dorsally placed splint. The aluminum with foam-backed splint is cut to a length of about 4 cm or the length from the distal tip of the nail plate to the distal creases of the PIP joint. A pair of shearing scissors is used to excavate the middle one third of the foam padding (Photograph 4). Each end of the splint is fashioned to a gradually contoured 58 to

158 of hyperextension (Photograph 5). The patient is instructed to hold the injured finger in hyperextension (Photograph 6). The splint is then affixed to the dorsum of the digit by 2 separate tapings (Photograph 7).

Discussion

Hand and upper extremity injuries are common in the ED. A review of the National Electronic Injury surveillance

Photograph 4 Scissors excavate middle one third of padding.

Modified dorsal finger splint for mallet finger 147

Photograph 5 Kleinert modified dorsal finger splint.

System shows that the Fingers and hand are the most frequent body parts injured at work and treated in hospital EDs [13]. Fractures of the digits are a significant subset of these injuries, and the distal phalanx is the most commonly fractured phalanx [14,15].

A mallet finger fracture must be correctly diagnosed and treated from the ED to prevent the pain and disability of a mallet finger deformity. A careful history, precise physical examination, and accurate radiographic reading will lead to the diagnosis. The initial treatment is essential. A properly fashioned and applied dorsal splint with referral to a hand or orthopedic surgeon will insure that a mallet finger deformity is best prevented.

Photograph 7 Applied splint.

There is controversy and disagreement over treatment options [16-20]. However, most agree that in a closed rupture or avulsion fracture, if there is no Joint dislocation or instability and less than one third of the articular surface is involved, conservative treatment is preferred [21,22]. A typical treatment regime is 8 weeks of continual splinting. Splinting requires patient compliance and can become uncomfortable while leading to its own complications, including maceration and Skin necrosis [23]. Several investigators have noted the complications of splinting these injuries including one study with a reported 45% complication rate [24].

Photograph 6 Injured finger in hyperextension. Photograph 8 Swan neck deformity splint.

148 R.G. Hart et al.

There are several specific issues to keep in mind to prevent potential problems or complications of splinting. The degree of hyperextension should not cause pain or skin blanching. Excessive hyperextension must be avoided because of the potential for blistering and maceration of skin over the dorsum of the joint. The splint itself must not put direct, sustained pressure at the DIP joint. The PIP joint should not be included in the splint unless a compensatory swan neck deformity is noted (Photograph 8). Displaced fractures should be reduced before splinting.

The Kleinert modified dorsal finger splint is an excellent choice for these hand-injured patients. It will insure that the digit is positioned properly, maintained in position, and there is minimal exposure to complications including Skin breakdown and vascular compromise. The splints are easily fashioned for form fitting hyperextension, and the excavated area greatly reduces the potential for skin maceration at the DIP joint. The patients position their finger in a comfortable hyperextended position that allows ease of affixing the splint. The splints are inexpensive, provide patient comfort, and encourage patient compliance. The ultimate goal is healing with a pain-free fully functioning DIP joint.

References

  1. Robb WA. The results of treatment of mallet finger. J Bone Joint Surg [ Br] 1959;41B(Aug):546 – 9.
  2. Schneider LH. Fracture of the distal interphalangeal joint. Hand Clin 1994;10(2):277 – 85.
  3. Simpson D, McQueen MM, Kumar P. Mallet deformity in sports. J Hand Surg [Br] 2001;26(1):32 – 3.
  4. Wehbe MA, Schneider LH. Mallet fractures. J Bone Joint Surg 1984;66A(5):658 – 69.
  5. Wang QC, Johnson BA. Fingertip injuries. Am Fam Physician 2001;63(10):1961 – 6.
  6. Evans D, Weightman B. The PIP flex splint for treatment of mallet finger. J Hand Surg [Br] 1988;13(2):156 – 8.
  7. Gooding CA. Spoon splint for mallet finger. Am Fam Physician 1984;29(1):23.
  8. Lester B, Jeong GK, Perry D, et al. A simple effective splinting technique for the mallet finger. Am J Orthop 2000;29(3):202 – 6.
  9. Maitra A, Dorani B. The conservative treatment of mallet finger with a simple splint: a case report. Arch Emerg Med 1993;10(3):244 – 8.
  10. Stack HG. A modified splint for mallet finger. J Hand Surg [Br] 1986;11(2):263.
  11. Warren RA, Norris SH, Ferguson DG. Mallet finger: a trial of two splints. J Hand Surg [Br] 1988;13B(2):151 – 3.
  12. Wilson SW, Khoo CTK. The Mexican hat splint–a new splint for the treatment of closed mallet finger. J Hand Surg [Br] 2001;26B(5): 488 – 9.
  13. Sorock GS, Lombardi DA, Hauser RB, et al. Acute traumatic occupational hand injuries: type, location and severity. J Occup Environ Med 2002;44(4):345 – 51.
  14. Van Onsder EB, Karim RB, Hage JJ, et al. Prevalence and distribution of hand fractures. J Hand Surg [Br] 2003;28(5):491 – 5.
  15. Doraiswamy NV, Baig H. Isolated Finger injuries in children– incidence and aetiology. Injury 2000;31(8):571 – 3.
  16. Abouna JM, Brown H. The treatment of mallet finger. The results in a series of 148 consecutive cases and a review of the literature. Br J Surg 1968;55(9):653 – 67.
  17. Clement R, Wray RC. Operative and nonoperative treatment of mallet finger. Ann Plast Surg 1986;16(2):136 – 41.
  18. Gaberman SF, Diao E, Peimer CA. Mallet finger: results of early versus delayed closed treatment. J Hand Surg [Am] 1994;19(5): 850 – 2.
  19. Geyman JP, Fink K, Sullivan SD. Conservative versus surgical treatment of mallet finger: a pooled quantitative literature evaluation. J Am Board Fam Pract 1998;11(5):382 – 90.
  20. Kaleli T, Ozturk C, Ersozius S. external fixation for surgical treatment of a mallet finger. J Hand Surg [Br] 2003;28(3):228 – 30.
  21. Okafor B, Mbubaegbu C, Munshi I, et al. Mallet deformity of the finger. Five year follow-up of conservative treatment. J Bone Joint Surg [ Br] 1997;79(4):544 – 7.
  22. Richards SD, Kumar G, Booth S, et al. A model for the conservative management of mallet finger. J Hand Surg [ Br] 2004;29(1):61.
  23. Rayan GM, Mullins PT. Skin necrosis complicating mallet finger splinting and vascularity of the distal interphalangeal joint overlying skin. J Hand Surg [Am] 1987;12(4):548 – 52.
  24. Stern P, Kastrup JJ. Complications and prognosis of treatment of mallet finger. J Hand Surg 1988;13A:341 – 6.