ORIGINAL ARTICLE - PERIPHERAL NERVES
An anatomical study of so-called fibrous bands around the ulnar nerve
distal to the cubital tunnel
José Fernando Guedes-Correa
Rosana Siqueira Brown
Received: 15 March 2018 /Accepted: 3 May 2018
Springer-Verlag GmbH Austria, part of Springer Nature 2018
Background Fibrous bands (FB) are structures that cross the ulnar nerve (UN), distal to the cubital tunnel (CT). In surgical
decompression of the UN in the elbow region, by endoscopy, these FB significantly impact UN visibility. The aim of the current
study was to characterize the anatomical characteristics of these FB distal to the CT.
Methodology Eighteen formalinized upper limbs were dissected, nine right and nine left, within the Department of Anatomy of
the Federal University of the State of Rio de Janeiro (UNIRIO). The dissections were performed with micro techniques, under a
magnifying glass and a microscope. Classical UN exposure was established in the elbow region.
Results Of the 18 upper limbs studied, 50% lacked any FB. When present, both the number and location of the FB varied, as near
to the cubital tunnel as 3 cm past the UN’s entrance into the tunnel, and as far away as almost 11 cm distal to it. Overall, there were
no FB on either the left or right side in three cadavers (33.3%), FB on both the left and right side in three, and FB only on the left
in three, meaning that FB were twice as common in left limbs (n = 6) as on the right (n =3).
Conclusions Our study identified FB in 50% of the dissected limbs, all within 3–11 cm of the CT, though their number and
location varied. Further studies are necessary to describe FB variations associated with compressive neuropathies of the UN distal
to the CT.
Keywords Cubital tunnel
The most frequent compressive neuropathy in the upper limbs
is in the carpal tunnel region, affecting the median nerve. The
second most common is compression of the ulnar nerve (UN)
within the cubital tunnel (CT) . Compressive neuropathy of
the UN is characterized by pain in the elbow’s medial region,
paresthesia in the fourth and fifth fingers, and weakening of the
intrinsic muscles of the hand and adduction of the thumb, in
some patients. In more advanced cases, upon inspection during
the physical exam, it is possible to observe a clawed hand and
atrophy of the intrinsic muscles of the hand, especially the first
dorsal interossei and hypothenar muscles .
Ulnar nerve decompression in the elbow region is
intended to relieve symptoms and prevent the progression
of motor and sensory dysfunction. Two basic types of sur-
gical treatment are suggested: open surgery and endoscopy.
The conventional open surgery techniques for decompres-
sion of the UN in the elbow are in situ decompression,
subcutaneous transposition, intramuscular transposition,
sub-muscular transposition, and a medial epicondylectomy.
In the 1990s, Tsai described an endoscopic surgical ap-
proach to treating CT syndrome, a minimally invasive meth-
od of treatment relative to traditional open techniques, gen-
erally affording patients faster recovery of daily activities,
shorter hospital stays, and fewer complications [14, 15].
This technique was modified later by others [2, 4, 5, 7, 14].
Traditionally, five areas of UN compression are known to
exist within the elbow region . These are (1) the arcade of
Struthers, which, when present, consists of a fibrous band that
connects the medial head of the triceps to the medial
intermuscular septum; (2) the medial epicondyle of the humer-
us; (3) the arcuate ligament of Osborne; (4) the anconeus
epitrochlearis (an anatomical muscular variation); and (5) the
* Rosana Siqueira Brown
Division of Neurosurgery, School of Medicine, Gaffrée e Guinle
University Hospital, Federal University of Rio de Janeiro State
(UNIRIO), 775 Mariz e Barros Street, Rio de Janeiro, RJ 20270-901,