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Anatomy
Case report
Higher division of the extensor digitorum longus muscle: A
cadaveric case report.
Abstract
Introduction
The higher division of extensor
digitorum longus (EDL) in the leg is
seldomly reported in the past. This
paper reports a cadaveric case of
higher division of the extensor
digitorum longus muscle.
Case report
During a regular dissection, we came
across a rare anatomical variation of
the EDL, in an adult male cadaver. At
the level of the upper part of the leg, a
separate long slender tendon arising
from the EDL was observed. This
tendon coursed between the tibialis
anterior and EDL muscles in the upper
part of the leg, between the extensor
halllucis longus and EDL muscles in
the lower part of the leg. The tendon
divided into two tendinous slips for
the second and third toes, over the
dorsum of the foot. The main portion
of the EDL muscle became completely
tendinous on the dorsum of the foot
and divided into two tendinous slips
for the third and fourth toes. The
insertion of the all the four tendinous
slips was found to be normal.
Conclusion
Awareness of presence of an extra
tendon in the anterior compartment
of leg is crucial while treating the
compartment syndrome.
and anterior inter-muscular septum.
The muscle becomes tendinous while
passing deep to the superior and
inferior retinacula. Usually, it divides
into four tendons on the dorsum of
the foot for the lateral four toes. The
tendons for the second, third and
fourth toes, at the level of the
metatarsophalangeal joints joined by
the tendons of the extensor digitorum
brevis to form the dorsal digital
expansion. Through this expansion
each of the EDL tendons finally get
inserted to the base middle and distal
phalanges1. EDL muscle frequently
shows variations in the arrangement
and insertion of the tendons in the
dorsum of the foot2,3,4,5. The higher up
division of EDL in the leg is seldom
reported in the literature6. Herein, we
report a rare case of higher up
division of the EDL tendon in the
upper part of the leg and discuss its
clinical significance.
Case report
During a regular dissection, we came
across a rare anatomical variation of
EDL in an approximately 55-year-old
male cadaver. The observed variation
was unilateral and it was observed in
the right leg. The EDL arose normally
from the lateral condyle of the tibia,
medial surface of the fibula and the
interosseous membrane. Then at the
level of the upper part of the leg, it gave
a separate long tendon. This long
slender tendon ran between the tibialis
anterior and EDL in the upper part of
the leg, between the extensor hallucis
longus and EDL in the lower part of the
leg (Figure 1). On the dorsum of the
foot, it divided into two tendinous slips
for the second and third toes. The main
portion of the EDL became completely
tendinous after passing deep to the
inferior extensor retinaculum, then
divided into two slips for the third and
fourth toes (Figure 2). The insertion of
all the four EDL tendinous slips to the
lateral toes was found to be normal.
EDL muscle received the nerve supply
from the deep peroneal nerve.
Discussion
The EDL is one of the anterior
compartment muscles of the leg. For
many years, EDL has been an area of
special interest and it has been studied
in various fields such as comparative
anatomy, embryology, morphology and
electromyography5. The EDL muscle
frequently shows variation in the
arrangement and insertion of its
tendons.
Introduction
The EDL muscle takes continuous
origin from the lower surface of the
tibial lateral condyle, upper one third
of the fibular medial surface, adjacent
inetrosseous membrane, deep fascia
*Corresponding author
Email: [email protected]
1Department of
Anatomy, Melaka Manipal
Medical College, Manipal University, Manipal,
Karnataka, India.
2Department of Anatomy, Yenepoya Medical
College, Yenepoya University, Mangalore,
Karnataka, India.
Figure 1: Dissection of the right leg and dorsum of the foot showing the higher up
division of the extensor digitorum longus muscle (EDL). Note the origin of the long
slender separate tendon (EDLT) from the EDL, in the upper part of the leg. (PT: peroneus
tertius, EHL: extensor hallucis longus muscle, TA: tibialis anterior muscle).
Licensee OAPL (UK) 2014. Creative Commons Attribution License (CC-BY)
FOR CITATION PURPOSES: Jetti R, Sirasanagandla SR, Nayak BS, Gorantla VR, Shetty AS. Higher division of the
extensor digitorum longus muscle: A cadaveric case report. OA Case Reports 2014 Feb 25;3(2):12.
Competing interests: None declared. Conflict of interests: None declared.
All authors contributed to conception and design, manuscript preparation, read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
R Jetti1, S R Sirasanagandla1*, B S Nayak1, V R Gorantla1, A S Shetty2
Page 2 of 2
Case report
Figure 2: Closer view of the right foot showing the separate tendon of the extensor
digitorum longus muscle (EDLT) and the tendon of the main extensor digitorum
longus muscle (EDL). Note the four tendinous slips (asterisks) for the lateral four toes
from the both EDLT and EDL. (TA: tibialis anterior, PT: peroneus tertius, EHL:
extensor hallucis longus).
It may give an additional slip to the
base of the proximal phalanx of the
second toe, the first interosseous
muscle and the anterior end of the
fifth metatarsal bone. Sometimes, it
may be connected to the extensor
hallucis longus by a slip, extensor
digitorum brevis by a cross band and
peroneus tertius by a slip. Further, the
digital tendon to each toe may be
doubled or rarely tendon to the
second and little toes alone may be
doubled2,3,4,5,6. Rarely, one of the four
tendons may be absent5. Sometimes
peroneus tertius tendon may arise
from the fourth digital tendon7. The
higher up division of the common
tendon of the EDL is rarely reported in
the literature. In the past, Arora et al.
have observed the higher up division
of the common tendon of the EDL in
the lower part of the leg. In this case,
the EDL common tendon divided
initially into three tendons in the
lower part the leg, the medial most
tendon re-divided on the dorsum of
the foot and finally there were four
tendons for lateral four toes6.
Contrary to previous cases, we report
a rare case of higher division of EDL at
a much higher level in the leg. EDL
tendons diameter is quite enough for
the need of the tendon grafts and
reconstruction procedures, so they
are usually used in reconstruction of
ankle joint lateral ligaments and
Achilles tendons8 and also used for
free tendon grafts9. Awareness of
anatomical variation observed in the
present case may be clinically
important during the selection of the
donor
site
for
tendon
graft
procedures. Knowledge of occurrence
of an extra tendon is also important
during the diagnosis and surgical
release of compartment syndrome of
the leg. Closed rupture of EDL tendons
are very rarely reported in the
literature. Hattori et al. have reported
a case of closed subcutaneous rupture
of the EDL. They performed a
biomechanical
study
on
three
cadavers, to reveal the mechanisms of
EDL tendons rupture. They concluded
that EDL rupture occurred during
plantar flexion10.
Conclusion
In cases of the higher division of the
EDL muscle, the pressure on the bare
tendon while it is passing through the
inferior retinaculum will be high and
the chances of ruptures are
predominant.
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Crossman AR, Gatzoulis MA, Healy JC, et
al. Gray’s Anatomy: The Anatomical
Basis of Clinical Practice. 40th ed., vol.
1198. London: Elsevier, Churchill
Livingstone, 2008, pp-1418-1419.
2. Macalister A. Muscular anomalies in
human anatomy. Trans R Ir Acad. 1985;
25: 125-7.
3. Gray H, Clemente CD. Grey’s Anatomy
of the Human Body, 30th American edn.
In Muscles and fasciae of the leg.
Philadelphia: Lea & Febiger. 1985. Pp
574–5.
4. Williams PL. Gray’s Anatomy, 38th
edn. Edinburgh: Churchill Livingstone,
1995.
5. Sakuma E, Kato H, Honda N, Mabuchi
Y, Soji T. A rare anomaly of the extensor
digitorum longus. Anat Sci Int. 2004
Dec;79:235-8.
6. Arora AK, Verma P, Abrol S.
Evaluation of the variations at the
origin and insertion of extensor
digitorum longus: clinical correlation
and literature review. Journal of
Research in Medical Education & Ethics.
2011 Mar;1(1):50-53.
7. Bhatt CR, Meenakshi, Modi S, Mehta
CD. Variation in peroneus teritius
tendon and its clinical implications.
J.Orthopaedics. 2010;7(2)e1.
8. Kim SW, Hong JP, Lee WJ, Chung YK,
Tark KC. Single-stage Achilles tendon
reconstruction using a composite
sensate free flap of dorsalis pedis and
tendon strips of the extensor digitorum
longus in a complex wound. Ann Plast
Surg. 2003 Jun;50,653–7.
9. Green DP. Operative Hand Surgery,
3rd edn. Churchill Livingstone, New
York, 1993.
10. Hattori K, Hiraoka S, Ishida Y,
Sugimoto K, Tanaka Y, Morita Y,
Yoshinori Takakura. Closed rupture of
the extensor digitorum longus tendon:
A case report and biomechanical
analysis of rupture mechanism. The
Foot. 2007 Dec;17(4):220-223.
Licensee OAPL (UK) 2014. Creative Commons Attribution License (CC-BY)
FOR CITATION PURPOSES: Jetti R, Sirasanagandla SR, Nayak BS, Gorantla VR, Shetty AS. Higher division of the
extensor digitorum longus muscle: A cadaveric case report. OA Case Reports 2014 Feb 25;3(2):12.
Competing interests: None declared. Conflict of interests: None declared.
All authors contributed to conception and design, manuscript preparation, read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
References