Eur J Plast Surg (2006) 28: 532–533
I. De Greef
L. De Smet
Accessory extensor pollicis longus: a case report
Received: 22 March 2005 / Accepted: 6 October 2005 / Published online: 10 December 2005
# Springer-Verlag 2005
Abstract A rare case is reported in which the accessory
extensor pollicis longus was discovered during dorsal wrist
surgery. The morphology of this tendon corresponds with
four previously reported cases.
Despite the numerous reports on anomalies of the extensor
tendons, the number of case reports on supernumerary ex-
tensor pollicis longus (EPL) tendon is rare: only seven
cases have been reported in the recent literature.
A 54-year-old Turkish man underwent a radiocarpometa-
carpal arthrodesis for severe osteoarthritis of the wrist of
During the approach, an abnormal configuration of the
EPL extensors was observed. One tendon of normal ap-
pearance and diameter was seen in the third compartment.
The other one run into the fourth compartment and was
markedly thinner. Pulling on both tendons caused exten-
sion of the interphalangeal joint of the thumb (Fig. 1).
More proximal dissection revealed a separate muscle
belly for each EPL tendon. There was no obvious con-
nection with the muscle belly of the extensor indicis pro-
prius nor with the extensor digitorum communis.
As far as we could see, the extensor pollicis brevis and
the abductor pollicis longus were present and normal.
As indicated in a recent paper by Sawaizumi et al. , only a
few cases of EPL tendon duplication have been described.
Our case mostly resembled the ones reported by Beatty
et al. , Chiu , Cohen and Haber  and Kaplan and
Nathan . These were of an accessory tendon arising from
another muscle located between the normal EPL and the
extensor indicis proprius.
In Culver’s clinical case and Cauldwell’s cadaver
dissections (referred to by Sawaizumi et al. ), the EPL
had one slip to the thumb and one to the index. This entity
is called “extensor pollicis and indicis communis”. The
case of Sawaizumi et al.  is very peculiar since one
tendon slip passed over the extensor retinaculum, and one
tendon ran into a separate tunnel between the first and
Fig. 1 Surgical findings. One EPL (a) tendon in its normal local-
ization and one thinner EPL (b) into the fourth compartment
I. De Greef
L. De Smet (*)
Hand Unit, Department of Orthopedic Surgery,
University Hospitals Leuven,
Weligerveld 1, Louvain,
3212 Lubbeek, Belgium