1. TIPS AND TECHNIQUES
A Novel Hook Plate Fixation Technique for the Treatment
of Mallet Fractures
Kanthan Theivendran, BSc, MBBS, Andrew Mahon, MSc, FRCSI(Tr and Orth),
and Vaikunthan Rajaratnam, MBBS(Mal), AM(Mal), MBA(USA), FRCS(Ed),
FRCS(Glasg), FICS(USA), Dip Hand Surgery(Eur)
We describe a new technique for open reduction and
Abstract: Bony mallet injuries are generally treated nonoperatively,
but when the fragment involves a significant percentage of the
internal fixation (ORIF) of mallet fractures using a 1.3-mm
articular surface, articular incongruity and instability can occur. A
hook plate (Teoh Lam-Chuan, Singapore General Hospital,
number of techniques have been described for the fixation of such
personal communication, 2005).
fractures and each has its own problems. Anatomic reduction and
secure fixation of small fragments can be challenging. Our objective
TECHNIQUE
is to describe a new surgical technique using a 1.3-mm hook plate
that provides good reduction and stable fixation of a mallet fracture,
Indication for this procedure includes patients with a
with early mobilization of the distal interphalangeal joint.
clinical mallet deformity, with radiographic evidence of a
dorsal intra-articular fracture fragment involving more than
Key Words: fracture, hook plate, internal fixation, mallet, 30% of the base of the distal phalanx.
open reduction The patient is positioned supine on the operating table,
(Ann Plast Surg 2007;58: 112–115)
with the hand prepared with standard antiseptic solutions. A
digital local anesthetic block is used and a sterile digital
tourniquet for the injured finger. A dorsal approach using a Y
incision is made over the fracture site to facilitate adequate
midline exposure of terminal phalanx. The nailbed is elevated
T he management of mallet fractures of the hand represents
a unique and problematic challenge. The mechanism of
injury usually involves axial loading of the fingertip, with
off the periosteum (in a similar manner to performing a
vascularized nailbed transfer and avoiding damage to the
hyperextension at the distal interphalangeal (DIP) joint, re- germinal matrix) of the distal phalanx. A 1.3-mm 2-hole
sulting in a fracture of the dorsal lip of the base of the distal Compact Hand Set (AO, Davos, Switzerland) plate is modi-
phalanx. Treatment modalities range from splinting alone,1–3 fied by cutting the proximal hole with plate cutters (Fig. 1A).
which has produced satisfactory results, to operative fixation The cut ends spring open and are bent volarly into hooks (Fig.
for fragments involving more than 30% of the articular 1B, C). Two very small longitudinal incisions are made in the
surface, with or without subluxation of DIP joint.4,5 terminal tendon. The hooks are passed through these slips
Nonoperative treatments have resulted in chronic insta- around the dorsal lip at the distal edge of the fracture
bility, joint subluxation, osteoarthritic deformity, resulting in fragment. The hooks grab onto the articular surface at the
cosmetically unacceptable outcomes.4,6 Healing of the bony dorsal lip in an area which does not articulate with the middle
fragment with displacement can lead to extensor lag and a phalanx, so there is no interference with DIP joint function.
swan-neck deformity.2 The hooks are then used to control and reduce the fracture
Various techniques have been described in the literature fragment. A 1.0-mm K-wire can be used to help reduce and
for operative fixation of mallet fractures. These include using hold the fracture fragment temporarily while applying the
Kirschner wires (K-wires),6 –10 tension band fixation,4,11 in- plate (Fig. 1D, E). The distal end of the plate with the
ternal suture,12 compression pin fixation,13 screw fixation,14 complete hole is held onto the distal phalanx using a 6-mm
and volar plate advancement arthroplasty15. screw. The self-tapping 6-mm titanium screw is advanced
obliquely using a handheld screwdriver, thereby levering on
the distal hole to reduce the fracture (Fig. 1E). The screw is
Received April 9, 2006, and accepted for publication, after revision, June
6, 2006.
then advanced perpendicular to the distal phalanx, thereby
From the Birmingham Hand Centre, University Hospital Birmingham, Selly anchoring the fragment in position (Fig. 1F), and the wound
Oak Hospital, Birmingham, UK. is closed. This provides compression of the fracture fragment
No financial support was received for this article. at the fracture site using the “tension band” principle. In most
Reprints: K. Theivendran, BSc, MBBS, 81 Pennine Way, Ashby-de-la- cases, a modified 2-hole plate can be used; however, for a
Zouch, Leicestershire, LE65 1EZ, UK. E-mail: kanthan@hotmail.co.uk.
Copyright © 2006 by Lippincott Williams & Wilkins larger unstable dorsal fragment, a modified 3-hole plate with
ISSN: 0148-7043/07/5801-0112 2 hooks and 2 holes may be required. The longer plate allows
DOI: 10.1097/01.sap.0000232858.80450.27 the titanium screw to be placed in the distal fragment to
112 Annals of Plastic Surgery • Volume 58, Number 1, January 2007

2. Annals of Plastic Surgery • Volume 58, Number 1, January 2007 Novel Hook Plate Fixation Technique
FIGURE 1. Operative technique for
the application of the titanium
hook plate and screw.
provide secure fixation. A radiographic image intensifier is
used to assess reduction. Postoperatively, the injured finger is
placed in a mallet splint for 2 weeks and then protected by
immobilization with a splint for a further 3 weeks. Radio-
graphic images are obtained after the procedure to assess
bony union.
CASE REPORT
A 53-year-old right-hand-dominant writer had injured
his left ring finger after falling on a dry ski slope. He was seen
in the emergency department 6 days after the injury. He had
complained of pain, swelling, and deformity over the DIP
joint. On clinical examination, there was dorsal tenderness
and swelling, with extensor lag at the DIP joint. Radiographs
depicted a dorsal avulsion fracture of the base of the terminal
FIGURE 2. Lateral (A) and anterior-posterior (B) radiographs
of a mallet fracture with 50% involvement of articular sur- FIGURE 3. Extension (A) and flexion (B) of the DIP joint
face. showing excellent range of motion of the ring finger.
© 2006 Lippincott Williams & Wilkins 113

3. Theivendran et al Annals of Plastic Surgery • Volume 58, Number 1, January 2007
phalanx (Fig. 2A, B). The patient was referred to the hand
surgeon and underwent an ORIF 2 days later.
There was mild volar subluxation noted under a digital
anesthetic block. Through a dorsal Y incision, the nailbed
was elevated off the periosteum from the proximal part of the
distal phalanx. The exposed fracture fragment was reduced
and held temporarily with a single 1.0-mm K-wire. The
1.3-mm hook plate was then applied by the usual method
described previously. The DIP joint was immobilized for 2
weeks, with protected mobilization for a further 3 weeks.
Six months after the procedure, the patient had 8° to 70° FIGURE 5. Dorsal view showing a healed scar with no nail-
of pain-free range of motion at the DIP joint (Fig. 3). The patient bed deformity.
had returned to normal activities at 5 weeks and had no disabil-
ity, with a DASH (disabilities of the arm, shoulder and
hand)16,17 score of 0 at 6 months. The fracture had united at 7 anatomic reduction, with stable fixation of a large dorsal bony
weeks, with no articular step (Fig. 4). There were no complica- fragment. The patient treated by this method had good,
tions, and the patient was satisfied with the treatment. pain-free range of motion at the DIP joint, with bony union at
7 weeks. The use of the low-profile plate did not cause any
skin irritation or nailbed deformity (Fig. 5), and there was no
DISCUSSION radiographic evidence of plate loosening. It is generally
There have been conflicting reports in the literature indicated that fractures involving less than 30% of the artic-
regarding the management of mallet fractures. Nonoperative ular surface should be treated conservatively with a mallet
treatment has been proposed by Wehbe and Schneider,2 splint. However, for a larger displaced fragment, a minimally
including those with fracture subluxation of the distal pha- invasive technique of extension-block percutaneous K-wire
lanx. Many authors have advocated operative fixation with pinning is easy to perform and is an effective, safe alternative
larger dorsal fragments with palmar subluxation.5,6,18 Oper- to the conservative treatment of displaced mallet frac-
ative techniques using K-wires,7 tension band wires,4,8 pull- tures.20 –22 We would advocate this treatment for the most
out sutures,19 miniscrews,14 and volar plate arthroplasty15 part; however, stiffness and swelling may persist as the DIP
have been reported. joint is rigidly immobilized for up to 6 weeks as compared
The operative goals for the treatment of mallet fractures with 2 weeks with the hook plate.
are to provide anatomic reduction with rigid fixation while We recommend the use of the hook plate as it offers
allowing early joint motion to prevent contractures at the DIP anatomic reduction, rigid internal fixation with early joint
joint. Many of the operative procedures described can be mobilization. This technique provides an alternative and
demanding and may obstruct early joint motion. The hook acceptable treatment modality, especially in large dorsal
plate technique is relatively simple to perform and provides fragment mallet fractures, with or without subluxation of the
terminal phalanx.
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