10 to 15 year follow-up after mallet finger fracture. A pilot study on the relation between anatomical position and radiological osteoarthritis.

The mallet finger injury is the most frequently encountered closed tendon
injury of the finger. These injuries involves avulsion of the extensor
mechanism at the base of the distal phalanx and in case of a mallet finger
fracture (MFF) the dorsal base of the phalanx is fractured as well. The
treatment of MFF is usually conservatively with a splint and only in specific
cases surgically. Several surgical techniques have been described in
literature, some comparing outcome to splinting, but the efficacy of treatment
modality has been shown to vary. There is an indication for operative treatment
in cases where involvement of articular surface is greater than one-third
and/or by palmar subluxation. Without accurate correction of the joint surface,
the patient has an increased risk for early osteoarthritis (OA), swan-neck
deformity, and persistent distal interphalangeal (DIP) joint-stiffness.
Surgical procedures though, have a higher complication rate than splinting and
a substantial part develops long-term disabilities.
To date, evidence is lacking to determine the best treatment for mallet finger
fractures. In the last couple of years, there has been an increased tendency to
perform surgery in case of a mallet finger fracture. A retrospective study with
follow-up is planned to study the relation between radiological OA and the
anatomical position.

The primary objectives are to assess the degree of OA that patients develop 10
to 15 year after a mallet finger fracture, to find out whether there is a
difference in degree of OA between conservatively treated patients with and
without an indication for surgery according to the current guidelines and to
compare the degree of OA between the fractured and non-fractured fingers.

The secondary objectives are to measure the functional outcome after treatment,
to assess the prevalence of OA in our cohort and to study the difference in
degree of OA between patients who had the same non-anatomical position of the
fracture but received different treatment (operative versus conservative).

This is a retrospective pilot study, with a follow-up of 10 to 15 years. Out of
all patients diagnosed with a MFF between 2001 and 2006, and attended the
Reinier de Graaf Groep (RdGG) 100 patients will be included. The initial
treatment and X-rays will be reassessed. The patients with an anatomical
position of their MFF will be placed in group 1. The patients in this group
would be treated conservatively under the current guidelines and were also
treated conservatively at the time of trauma.
All other patients, those who did not have an anatomical position, will placed
in be divided in group 2 en 3. Group 2 will consist of patients who would be
operated under the current guidelines but were nevertheless treated
conservatively at the time of trauma.
Group 3 will consist of patients who would be operated under the current
guidelines and were also operated at that time.

For control and to study the differences in OA, the same non-fractured digit of
the other hand of all patients will be assessed as well. If this digit had a
mallet finger fracture as well, patients will be excluded. Patients will have
to visit the hospital once to complete questionnaires, to have an X-ray of the
fractured and the non-fractured fingers, and for physical examination of these
fingers.

The patients will have to come to the hospital once for the questionnaire, for
X-rays of their fingers (four in total) and a physical examination of the
fingers. The dosage of radiation exposure is approximately 4 x 0.001 mSv. This
is a negligible dosage, as in contrast, the yearly exposure to radiation from
natural sources is about 2 mSv. The radiation exposure due to the hand X-rays
represents about 1/500 of a normal yearly exposure.