the adult, mallet injury commonly occurs as either a soft tissue injury,
less often associated with a dorsal avulsion fracture. It arises from the
combination of an external flexion force on the distal interphalangeal
joint at the same time as attempted extension of this joint, with tissue
failure occurring at the extensor tendon insertion (Fig.
tissue mallet injuries may occur after a relatively trivial event,
such as using the fingertips to push folds out of a bedspread, a painless
event with no bruising. Soft tissue mallet injuries are best treated with
continuous extension splinting for six to eight weeks. Splinting may be
helpful even if the initial treatment is delayed as long as three months.
If the patient can not tolerate a continuous splinting program, the distal
interphalangeal joint may be pinned in slight hyperextension for six weeks.
fractures more often result from obvious trauma, such as being struck
on the fingertip while trying to catch a ball: "baseball finger". In the
majority of adult mallet fractures, the distal phalanx articulation remains
congruent and the fracture fragment involves less than one-third of the
joint surface. These injuries are best treated with extension splinting
for one month. Residual deformity is more likely with delayed treatment,
with an associated hyperextension posture of the proximal interphalangeal
joint, and in mallet fractures with a large avulsion fragment or with palmar
subluxation of the distal phalanx. Recognizing both the technical difficulty
and known complications of open treatment, these latter two fractures are
probably best treated with a percutaneous indirect reduction using extension
block pinning (Darder-Prats)
17). The majority of pediatric mallet injuries are fractures
involving the growth plate - usually Salter I,
less often Salter III.