ArticlePDF Available

A Cadaveric Study of Ulnar Nerve Innervation of the Medial Head of Triceps Brachii

DOI:10.1007/s11999-008-0535-6
Authors:
Halil Bekler at Dr.Lutfi Kirdar kartal eah
Halil Bekler
  • Dr.Lutfi Kirdar kartal eah
Valerie Wolfe at Columbia University
Valerie Wolfe
Melvin P Rosenwasser at Columbia University
Melvin P Rosenwasser
Download full-text PDF
Read full-text
Download citation

Abstract and Figures

The presence of a separately innervated muscle unit of the triceps may have possible surgical importance and can be used for motor reconstructions. The ulnar nerve is closely situated to the triceps muscle and rarely examined above the elbow. The aim of this cadaveric study was to explore a possible contribution of the ulnar nerve to motor innervation of the medial head of the triceps. We dissected 18 limbs from axillae to midforearm. The path of the ulnar nerve was followed, and examination was conducted of attachments to the triceps. Gross photographs were taken and samples histologically stained. Seventeen limbs had ulnar nerve branches proximal to the epicondyles that inserted on the medial head. Eleven of these branches were from the ulnar nerve trunk. The other six were nerve branches from the ulnar collateral branch of the radial nerve. The ulnar nerve and the ulnar collateral branch of the radial nerve are previously unrecognized sources of innervation of the medial head of the triceps brachii. These motor branches must be carefully preserved during the medial surgical approach above the elbow. The ulnar innervated part of the medial head of the triceps muscle may be used like an independent motor unit.
Figures - uploaded by Melvin P Rosenwasser
Author content
All figure content in this area was uploaded by Melvin P Rosenwasser
Content may be subject to copyright.
Content uploaded by Melvin P Rosenwasser
Author content
All content in this area was uploaded by Melvin P Rosenwasser
Content may be subject to copyright.
ORIGINAL ARTICLE
A Cadaveric Study of Ulnar Nerve Innervation of the Medial
Head of Triceps Brachii
Halil Bekler MD, Valerie M. Wolfe MD,
Melvin P. Rosenwasser MD
Received: 1 May 2008 / Accepted: 9 September 2008 / Published online: 11 October 2008
ÓThe Association of Bone and Joint Surgeons 2008
Abstract The presence of a separately innervated muscle
unit of the triceps may have possible surgical importance
and can be used for motor reconstructions. The ulnar nerve
is closely situated to the triceps muscle and rarely exam-
ined above the elbow. The aim of this cadaveric study was
to explore a possible contribution of the ulnar nerve to
motor innervation of the medial head of the triceps. We
dissected 18 limbs from axillae to midforearm. The path of
the ulnar nerve was followed, and examination was con-
ducted of attachments to the triceps. Gross photographs
were taken and samples histologically stained. Seventeen
limbs had ulnar nerve branches proximal to the epicondyles
that inserted on the medial head. Eleven of these branches
were from the ulnar nerve trunk. The other six were nerve
branches from the ulnar collateral branch of the radial
nerve. The ulnar nerve and the ulnar collateral branch of
the radial nerve are previously unrecognized sources of
innervation of the medial head of the triceps brachii. These
motor branches must be carefully preserved during the
medial surgical approach above the elbow. The ulnar
innervated part of the medial head of the triceps muscle
may be used like an independent motor unit.
Introduction
The triceps brachii has been recognized as receiving motor
innervation from the radial nerve with contributions from
C7 and C8, although studies have noted the branching
pattern to be inconsistent [4,5]. The specific origins of
radial innervation for each of the three heads of the triceps
have been described [9,10]. Gerwin et al. [3] likewise
observed trifurcation of the radial nerve at the lateral aspect
of the humerus that sent one branch to the medial head of
the triceps. Another branch has been reported to accom-
pany the ulnar nerve in its path for a time before insertion
and therefore is known as the ulnar collateral branch [7,8].
The ulnar nerve is the continuation of the medial cord of
the brachial plexus with contributions from C8 and T1 [11,
12]. The branching pattern of the ulnar nerve is not con-
sistently characterized. Sunderland [11,12], agreeing with
Linell’s original 1921 observation [6], noted the nerve
gives off no branches in the upper arm. Doyle and Botte [2]
noted the first branch of the ulnar nerve is classically
articular and originates in the cubital tunnel up to
approximately 1 cm proximal to the medial epicondyle.
We observed a thus far unreported phenomenon in
anatomic branching of the ulnar nerve. The presence of an
ulnar nerve branch contribution to triceps motor function
was observed in many surgical procedures that needed
ulnar nerve dissection proximal to the elbow.
The presence of an ulnar nerve-innervated muscle unit
of the triceps muscle has more than just scientific impor-
tance. The unit of triceps muscle innervated by the ulnar
nerve, completely independent of the radial nerve-inner-
vated main part of the triceps, may be used for motor
reconstructions. This cadaveric study was designed to
further document this connection with the aim of deter-
mining anatomically and histologically the ulnar nerve
Each author certifies that he or she has no commercial association (eg,
consultancies, stock ownership, equity interest, patent/licensing
arrangements, etc) that might pose a conflict of interest in connection
with the submitted article.
H. Bekler (&)
Department of Orthopaedic Surgery, Yeditepe University
Hospital, Devlet Yolu Ankara Cad 102/104, Kozyatag
˘i,
Istanbul, Turkey
e-mail: hibekler@yeditepe.edu.tr
V. M. Wolfe, M. P. Rosenwasser
Department of Orthopaedic Surgery, Trauma Training Center,
Columbia University Medical Center, New York, NY, USA
123
Clin Orthop Relat Res (2009) 467:235–238
DOI 10.1007/s11999-008-0535-6
contribution to the motor innervations of the medial head
of the triceps muscle.
Materials and Methods
Eighteen upper limbs from 10 skeletally mature fresh-fro-
zen cadavers were used in this study. Eight were left arms
and 10 were right. The mean age of the cadavers was
67 years (range, 41–82 years).
Using a standard medial skin incision, subcutaneous
tissues were exposed from the axillae to the midforearm.
The intermuscular septum was identified. The ulnar nerve
was found positioned behind the proximal edge of the
septum, preserved, and dissected along the anterior surface
of the medial head of the triceps muscle. At the elbow, the
ulnar nerve passes behind the medial humeral epicondyle
and medial to the ulnar collateral ligament and the olec-
ranon. It tracks distally between the humeral and ulnar
head of the flexor carpi ulnaris, reaching a position deep to
that muscle where it rests on the flexor digitorum profun-
dus. Our dissection was terminated at this level.
Careful examination was made of attachments between
the ulnar nerve and the medial head of the triceps brachii.
Where a nerve connection was noted, the ulnar nerve,
nerve branch, and portion of medial head of the triceps
muscle presumably innervated by the nerve were resected
and placed in formalin. Gross photographs were taken of
the nerve and its connection to the triceps.
Representative samples from each cadaver were
embedded in paraffin and 8-lm sections were cut using a
microtome. After deparaffinization and rehydration with
xylene and ethanol, some slides were stained with silver
nitrate, whereas others were stained with hematoxylin and
eosin. Nerve to muscle connections were noted.
The ulnar collateral branch of the radial nerve also was
identified in some of the specimens where it branched from
the radial nerve at the level of the brachioaxillary angle.
Results
Dissection was completed successfully in all 18 specimens.
In 17 of the 18 limbs, nerve branches were observed to
originate in the area of the ulnar nerve and to insert into the
medial head of the triceps. These nerve branches originated
between 4 and 10 cm proximal to the medial epicondyle.
They were either encased in or located in close proximity
with the mezonervosum but were easily grossly distin-
guished from this tissue. In 11 of the 17 specimens, the
nerve branch originated from the main ulnar nerve (Fig. 1).
The other six specimens had the accessory ulnar collateral
branch of the radial nerve described previously (Fig. 2). On
each specimen, this branch left the radial nerve at the level
of the brachioaxillary angle and traveled with the ulnar
nerve along the groove in the medial head of the triceps.
The branch, although not visible to the naked eye, was
identifiable at all times through x3.5 loupe magnification as
a distinct bundle of fascicles traveling with but not inter-
mingled with the ulnar nerve. In these specimens, the nerve
branches to the medial head of the triceps were seen to
originate from the ulnar collateral branch of the radial
nerve.
Histologic staining confirmed the observed connection
between the ulnar nerve and the medial head of the triceps
was indeed a nerve to muscle connection (Fig. 3).
Discussion
The presence of a separately innervated muscle unit of the
triceps may have possible surgical importance because it
might be used for motor reconstructions. The ulnar nerve is
very closely situated to the triceps muscle and rarely is
examined above the elbow. In this cadaveric study, we
Fig. 1A–B (A) A photograph (93.5 loupe magnification) and (B)
diagram show the origin of the nerve branch. The arrow indicates the
connective branch from the ulnar nerve to the medial head of triceps
brachii. Eleven of the 18 cadaveric specimens had this gross
connection, supporting our theory of ulnar innervation of at least a
portion of the triceps motor function. The branch passes over the ulnar
collateral branch of the radial nerve.
236 Bekler et al. Clinical Orthopaedics and Related Research
123
dissected 18 limbs from axillae to midforearm to explore a
possible contribution of the ulnar nerve to motor innerva-
tion of the medial head of the triceps. The ulnar nerve
innervation of the medial head of the triceps was supported
by this cadaveric study. The limitation of this study is that
we did not measure the precise location of the branches. In
a cadaver study, it is impossible to determine whether a
branch is motor or sensory, but the location of each branch
can be mapped. During this particular study, our main goal
was to determine the presence or absence of nerve
connection. Our attention was focused on defining the
nature of each connection; ie, whether it was a nerve or
whether it was connective tissue. Therefore, we did not
measure the location of the branches.
Although the majority of the observed nerve branches
originated from the main ulnar nerve, some also came from
the ulnar collateral branch of the radial nerve. This branch
of the radial nerve, although easily separated from the ulnar
nerve by loupe magnification, is situated so close to the
ulnar nerve as to be indistinguishable by the naked eye.
With the ulnar nerve branch innervation of the triceps,
the dual nerve supply could allow separation of the triceps
muscle. This could explain the clinical observation that
radial nerve denervation does not result in complete lack of
triceps function.
The triceps muscle and its main motor nerve, the radial
nerve, have multiple connection modalities. New advances
in peripheral nerve surgery such as neurotization of muscle
by direct suture of nerve end to muscle, or transfer of
healthy motor nerve branches to the motor nerve end of a
denervated muscle have given the surgeon great capacity
for motor reconstructions.
Witoonchart et al. [13] described the concept of using
the radial nerve branch to the long head of the triceps
brachii for reinnervation of the anterior branch of the
axillary nerve in upper brachial plexus injuries. In selected
cases, the ulnar collateral branch of the radial nerve to the
ulnar nerve or motor branch ramifying from the ulnar nerve
could be used for reinnervation of a denervated muscle
closely situated. Another possibility may be the transfer of
the entire muscle unit for motor use. This independent
motor unit may be helpful in restoring elbow flexion in
selected cases or it may be used like a motor unit of
forearm movement in the manner the brachialis muscle is
used [1]. If well described, this small selective donor site
would have an easy anatomic approach and acceptable
potential morbidities.
It is essential to change the current thought that no major
ulnar nerve branches occur above the elbow. Dissections
proximal to the epicondyles must be performed carefully so
as to avoid destruction of these branches, preventing partial
denervation and atrophy of the triceps muscle and addi-
tional fibrosis of the medial head and resultant postsurgical
elbow stiffness. Finally, the importance of the ulnar col-
lateral branch of the radial nerve must be emphasized. Our
anatomic dissections showed this nerve to be a distinct
entity with a diameter large enough to be appreciated easily
on loupe magnification. With popularization of neurotiza-
tion, this nerve would be a prime candidate for
reinnervation of denervated muscle through nerve-to-nerve
repair (for example, musculocutaneous nerve interruption
with resultant denervation of the biceps brachii). The nerve
also could be used for direct transfer to another muscle.
Fig. 2A–B (A) A photograph (93.5 loupe magnification) and (B)
diagram show the presence of the accessory ulnar collateral branch of
the radial nerve and the origin of the motor nerve branch. The
accessory ulnar collateral branch of the radial nerve is situated close
to and is grossly distinguishable from the ulnar nerve.
Fig. 3 The triceps muscle and nerve branch were clearly seen on
histologic examination of the specimen (Stain, Masson’s trichrome;
magnification, 940).
Volume 467, Number 1, January 2009 Innervations of Triceps 237
123
We conclude the ulnar nerve and the ulnar collateral
branch of the radial nerve are previously unrecognized
sources of triceps brachii innervation. Additional study will
be directed toward exploitation of these branches as
potential sources for reinnervation of denervated muscle by
direct nerve transfer without nerve grafting for manage-
ment of brachial plexus injuries and biceps brachii
denervation and eventually for reinnervation of other
muscles in the arm and forearm.
References
1. Bertelli JA. Brachialis muscle transfer to the forearm muscles in
obstetric brachial plexus palsy. J Hand Surg Br. 2006;31:261–265.
2. Doyle JR, Botte MJ. Nerve anatomy. In: Doyle JR, Botte MJ,
eds. Surgical Anatomy of the Hand and Upper Extremity.
Philadelphia, PA: Lippincott Williams & Wilkins; 2003:204.
3. Gerwin M, Hotchkiss RN, Weiland AJ. Alternative operative
exposures of the posterior aspect of the humeral diaphysis with
reference to the radial nerve. J Bone Joint Surg Am.
1996;78:1690–1695.
4. Gray H. The muscles and fasciae of the arm. In: Clemente CD,
ed. Anatomy of the Human Body. 30th Ed. Philadelphia, PA: Lea
and Febiger; 1985:529.
5. Guse TR, Ostrum RF. The surgical anatomy of the radial nerve
around the humerus. Clin Orthop Relat Res. 1995;320:149–153.
6. Linell EA. The distribution of nerves in the upper limb, with
reference to variabilities and their clinical significant. J Anat.
1921;55:79–112.
7. Morris H. The musculature. In: Anson BJ, ed. Human Anatomy.
12th Ed. New York, NY: McGraw-Hill; 1966:483.
8. Morris H. The nervous system. In: Anson BJ, ed. Human
Anatomy. 12th Ed. New York, NY: McGraw-Hill; 1966:1067–
1068.
9. O
¨zer H, Ac¸ar HI, Co
¨mert A, Tekdemir _
I, Elhan A, Turanli S.
Course of the innervation supply of medial head of triceps muscle
and anconeus muscle at the posterior aspect of humerus (ana-
tomical study). Arch Orthop Trauma Surg. 2006;126:549–553.
10. Stanescu S, Post J, Ebraheim NA, Bailey AS, Yeasting R. Sur-
gical anatomy of the radial nerve in the arm: practical
considerations of the branching patterns to the triceps brachii.
Orthopedics. 1996;19:311–315.
11. Sunderland S. The ulnar nerve. In: Sunderland S, ed. Nerves and
Nerve Injuries. 2nd Ed. New York, NY: Churchill Livingstone;
1978:728–749.
12. Sunderland S. The radial nerve. In: Sunderland S, ed. Nerves and
Nerve Injuries. 2nd Ed. New York, NY: Churchill Livingstone;
1978:802–819.
13. Witoonchart K, Leechavengvongs S, Uerpairojkit C,
Thuvasethakul P, Wongnopsuwan V. Nerve transfer to deltoid
muscle using the nerve to the long head of the triceps. Part I: an
anatomic feasibility study. J Hand Surg Am. 2003;28:628–632.
238 Bekler et al. Clinical Orthopaedics and Related Research
123
... Triceps long head branch is usually favored as a donor for the axillary nerve in (UBPIs) due to its adjacent anatomical location, easy dissection and identification, in addition to its matching diameter to the recipient nerve (Bekler et al., 2009;Loukas et al., 2013). Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). ...
... Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). In these circumstances, (TLMN) has been proposed as an alternative donor to the axillary nerve providing the surgeon with an adequate length (averaging 9.37 cm) allowing direct neural coaptation, easy dissection and identification, minimal morbidity (due to multiple nerve supply to the triceps medial head from either radial and/or ulnar nerves), and reasonable diameter (2 mm) (Bekler et al., 2009;Loukas et al., 2013). ...
... In this study, the authors have investigated the mean diameter and length of (TLN) and (TLMN) (3 ± 0.2 mm and 38 ± 5.6 mm; 3 ± 0.2 mm and 76 ± 10.2 mm respectively) which were comparable to the findings in other studies (Bekler et al., 2009;Loukas et al., 2013). ...
Antica
Article
Full-text available
  • Jan 2022
View
... Triceps long head branch is usually favored as a donor for the axillary nerve in (UBPIs) due to its adjacent anatomical location, easy dissection and identification, in addition to its matching diameter to the recipient nerve (Bekler et al., 2009;Loukas et al., 2013). Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). ...
... Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). In these circumstances, (TLMN) has been proposed as an alternative donor to the axillary nerve providing the surgeon with an adequate length (averaging 9.37 cm) allowing direct neural coaptation, easy dissection and identification, minimal morbidity (due to multiple nerve supply to the triceps medial head from either radial and/or ulnar nerves), and reasonable diameter (2 mm) (Bekler et al., 2009;Loukas et al., 2013). ...
... In this study, the authors have investigated the mean diameter and length of (TLN) and (TLMN) (3 ± 0.2 mm and 38 ± 5.6 mm; 3 ± 0.2 mm and 76 ± 10.2 mm respectively) which were comparable to the findings in other studies (Bekler et al., 2009;Loukas et al., 2013). ...
Comparison between long and lower medial head triceps branches in dual neurotization for shoulder function restoration in upper brachial plexus palsy
Article
  • Jan 2021
Purpose: In upper brachial plexus injury (UBPI), restoring shoulder function is crucial. This study compares the transfer of long and lower medial heads of triceps branches to the axillary nerve to achieve proper restoration of function. Patients and Methods: A retrospective comparative study was conducted between two groups of patients with (UBPI). Group I patients (10) [mean age: 19 ± 10.6 years] were managed by transferring triceps long head branch to axillary nerve while group II patients (8) [mean age: 26 ± 9.6 years] were managed by triceps lower medial head branch transfer. The mean time from injury to surgery was 6 ± 1.3 and 5 ± 1.7 months respectively. All patients were followed up for a minimum of 12 months with the assessment of VAS, DASH score, active range of motion (AROM) and strength of shoulder abduction and external rotation; in addition to shoulder endurance and strengths of donors. Postoperative, three-monthly, electrodiagnostic assessments were performed. Results: Postoperatively, the mean VAS and DASH scores; in addition to endurance time, showed significant enhancement in both groups. Patients in both groups have accomplished a mean abduction (AROM) of 98 ± 27.9 and 97 ± 11.9 respectively. The mean external rotation (AROM) was 48 ± 18.4 and 47 ± 9.2 respectively. Furthermore , group II patients had less triceps morbidity in addition to earlier and enhanced electrophysiological recovery. Conclusions: Dual neurotization for shoulder function restoration in (UBPI) is capable of providing proper functional results with minimal donor morbidity. The triceps lower medial branch provides an excelling donor due to less triceps morbidity, extra length; yet, earlier and enhanced electrophysiological recovery.
View
... Triceps long head branch is usually favored as a donor for the axillary nerve in (UBPIs) due to its adjacent anatomical location, easy dissection and identification, in addition to its matching diameter to the recipient nerve (Bekler et al., 2009;Loukas et al., 2013). Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). ...
... Occasionally, inadequate length of the nerve or initial damage occurs in cases of aberrant origin from the axillary nerve itself, which may result in restrictions of its use (Bertelli & Ghizoni, 2014;Colbert & Mackinnon, 2006;De Sèze et al., 2004). In these circumstances, (TLMN) has been proposed as an alternative donor to the axillary nerve providing the surgeon with an adequate length (averaging 9.37 cm) allowing direct neural coaptation, easy dissection and identification, minimal morbidity (due to multiple nerve supply to the triceps medial head from either radial and/or ulnar nerves), and reasonable diameter (2 mm) (Bekler et al., 2009;Loukas et al., 2013). ...
... In this study, the authors have investigated the mean diameter and length of (TLN) and (TLMN) (3 ± 0.2 mm and 38 ± 5.6 mm; 3 ± 0.2 mm and 76 ± 10.2 mm respectively) which were comparable to the findings in other studies (Bekler et al., 2009;Loukas et al., 2013). ...
Comparison between long and lower medial head triceps branches in dual neurotization for shoulder function restoration in upper brachial plexus palsy
Article
Full-text available
  • Dec 2020
Purpose In upper brachial plexus injury (UBPI), restoring shoulder function is crucial. This study compares the transfer of long and lower medial heads of triceps branches to the axillary nerve to achieve proper restoration of function. Patients and Methods A retrospective comparative study was conducted between two groups of patients with (UBPI). Group I patients (10) [mean age: 19 ± 10.6 years] were managed by transferring triceps long head branch to axillary nerve while group II patients (8) [mean age: 26 ± 9.6 years] were managed by triceps lower medial head branch transfer. The mean time from injury to surgery was 6 ± 1.3 and 5 ± 1.7 months respectively. All patients were followed up for a minimum of 12 months with the assessment of VAS, DASH score, active range of motion (AROM) and strength of shoulder abduction and external rotation; in addition to shoulder endurance and strengths of donors. Postoperative, three‐monthly, electrodiagnostic assessments were performed. Results Postoperatively, the mean VAS and DASH scores; in addition to endurance time, showed significant enhancement in both groups. Patients in both groups have accomplished a mean abduction (AROM) of 98° ± 27.9 and 97° ± 11.9 respectively. The mean external rotation (AROM) was 48° ± 18.4 and 47° ± 9.2 respectively. Furthermore, group II patients had less triceps morbidity in addition to earlier and enhanced electrophysiological recovery. Conclusions Dual neurotization for shoulder function restoration in (UBPI) is capable of providing proper functional results with minimal donor morbidity. The triceps lower medial branch provides an excelling donor due to less triceps morbidity, extra length; yet, earlier and enhanced electrophysiological recovery.
View
... Ulnar nerve is a branch of medial cord of brachial plexus with a root value of C8-T1. [1] This nerve passes superficially to the flexor retinaculum and enters the palm of the hand through the Guyon's canal. In the hand, it gives motor (hypothenar, 3 rd /4 th lumbricals, palmar/dorsal interossei muscles) and sensory (fifth digit and the medial half of the fourth digit) innervations. ...
2014 - SJA
Article
Full-text available
  • Apr 2022
View
... This direct relationship between the upper medial head motor branch and the ulnar nerve probably was the reason that some investigators have noted branches of the ulnar nerve to the triceps medial head. 22,23 Bekler et al. 24 observed innervation of the medial head by the ulnar nerve in as many as 61% of their dissections. Loukas et al. 25 found this innervation in 28% of their cases, while Jain et al. 26 noted it in 43% of their cases. ...
Triceps and cutaneous radial nerve branches investigated via an axillary anterior arm approach: new findings in a fresh-cadaver anatomical study
Article
Full-text available
  • Oct 2021
Objective: The authors sought to describe the anatomy of the radial nerve and its branches when exposed through an axillary anterior arm approach. Methods: Bilateral upper limbs of 10 fresh cadavers were dissected after dyed latex was injected into the axillary artery. Results: Via the anterior arm approach, all triceps muscle heads could be dissected and individualized. The radial nerve overlaid the latissimus dorsi tendon, bounded by the axillar artery on its superior surface, then passed around the humerus, together with the lower lateral arm and posterior antebrachial cutaneous nerve, between the lateral and medial heads of the triceps. No triceps motor branch accompanied the radial nerve's trajectory. Over the latissimus dorsi tendon, an antero-inferior bundle, containing all radial nerve branches to the triceps, was consistently observed. In the majority of the dissections, a single branch to the long head and dual innervations for the lateral and medial heads were observed. The triceps long and proximal lateral head branches entered the triceps muscle close to the latissimus dorsi tendon. The second branch to the lateral head stemmed from the triceps lower head motor branch. The triceps medial head was innervated by the upper medial head motor branch, which followed the ulnar nerve to enter the medial head on its anterior surface. The distal branch to the triceps medial head also originated near the distal border of the latissimus dorsi tendon. After a short trajectory, a branch went out that penetrated the medial head on its posterior surface. The triceps lower medial head motor branch ended in the anconeus muscle, after traveling inside the triceps medial head. The lower lateral arm and posterior antebrachial cutaneous nerve followed the radial nerve within the torsion canal. The lower lateral brachial cutaneous nerve innervated the skin over the biceps, while the posterior antebrachial cutaneous nerve innervated the skin over the lateral epicondyle and posterior surface of the forearm. The average numbers of myelinated fibers were 926 in the long and 439 in the upper lateral head and 658 in the upper and 1137 in the lower medial head motor branches. Conclusions: The new understanding of radial nerve anatomy delineated in this study should aid surgeons during reconstructive surgery to treat upper-limb paralysis.
View
... It has been suggested that each fascicle "may be considered an independent muscle with specific functional roles [3]. All three heads of the triceps brachii are classically believed to be innervated by the radial nerve [4]. However, the long head may be innervated by a branch of the axillary nerve [5]. ...
STUDY OF VARIANT HEADS OF TRICEPS MUSCLE WITH ITS DEVELOPMENTAL BASIS
Article
Full-text available
  • May 2013
Materials & Methods: The study on variant heads of triceps muscle was performed on 100 (200 specimens of superior extremities) embalmed donated cadavers (90 males & 10 females) in the department of Anatomy of K.J.Somaiya Medical College, Sion, Mumbai, India. The dissection of the arm and forearm was done meticulously to expose the triceps muscle. The variant heads of triceps muscle was observed. The neuro vascular pattern of the upper limb were also observed. The photographs of the variant heads of triceps muscle were taken for proper documentation. Observations: Out of 200 specimens of superior extremities the variant heads of triceps muscle were observed in 4 specimens. In all the 4 specimens, the fourth head of the triceps brachii muscle was originated from the postero-medial aspect of the shaft of the humerus just below the surgical neck. The variant fourth head of the triceps brachii muscle was supplied by the radial nerve. The fourth head passed directly over the neurovascular bundle containing the radial nerve and profunda brachii artery. The long, lateral and fourth heads of the triceps brachii muscle converged to form a superficial tendon which was inserted into the posterior part of the superior surface of the olecranon process of the ulna. The medial head of triceps muscle was partly inserted into the superficial tendon and partly into the posterior part of the superior surface of the olecranon process of the ulna. The associated altered anatomy of the nerves and vessels were not observed. All the variations were unilateral. Conclusion: The role of additional muscles in compression syndrome is a well known phenomenon. The knowledge of such type of variation is clinically important for Anatomists, Neurologists, Radiologists, Surgeons, Plastic surgeons and Orthopedicians.
View
... It has been suggested that each fascicle "may be considered an independent muscle with specific functional roles [3]. All three heads of the triceps brachii are classically believed to be innervated by the radial nerve [4]. However, the long head may be innervated by a branch of the axillary nerve [5]. ...
STUDY OF VARIANT HEADS OF TRICEPS MUSCLE WITH ITS DEVELOPMENTAL BASIS
Article
Full-text available
  • May 2013
Materials & Methods: The study on variant heads of triceps muscle was performed on 100 (200 specimens of superior extremities) embalmed donated cadavers (90 males & 10 females) in the department of Anatomy of K.J.Somaiya Medical College, Sion, Mumbai, India. The dissection of the arm and forearm was done meticulously to expose the triceps muscle. The variant heads of triceps muscle was observed. The neuro vascular pattern of the upper limb were also observed. The photographs of the variant heads of triceps muscle were taken for proper documentation. Observations: Out of 200 specimens of superior extremities the variant heads of triceps muscle were observed in 4 specimens. In all the 4 specimens, the fourth head of the triceps brachii muscle was originated from the postero-medial aspect of the shaft of the humerus just below the surgical neck. The variant fourth head of the triceps brachii muscle was supplied by the radial nerve. The fourth head passed directly over the neurovascular bundle containing the radial nerve and profunda brachii artery. The long, lateral and fourth heads of the triceps brachii muscle converged to form a superficial tendon which was inserted into the posterior part of the superior surface of the olecranon process of the ulna. The medial head of triceps muscle was partly inserted into the superficial tendon and partly into the posterior part of the superior surface of the olecranon process of the ulna. The associated altered anatomy of the nerves and vessels were not observed. All the variations were unilateral. Conclusion: The role of additional muscles in compression syndrome is a well known phenomenon. The knowledge of such type of variation is clinically important for Anatomists, Neurologists, Radiologists, Surgeons, Plastic surgeons and Orthopedicians.
View
... Just as the median nerve, it does not emit branches to the arm (Capitani and Beer, 2002). Some authors reported ulna innervation of the medial head of the triceps muscle on the posterior compartment of the arm, through the radial nerve associated with ulnar nerve branches (Pascual et al, 2013) or ulnar nerve branch innervating the triceps without existing communication with the radial nerve (Bekler et al, 2009). Some authors emphasize the possibility of innervation of the triceps by surgical technique. ...
Ulnar nerve contribution in the innervation of the triceps brachii muscle ulnar nerve to the triceps brachii
Article
The ulnar nerve is considered the thickest terminal branch of the medial cord in the brachial plexus and most authors does not mention the possibility of this nerve emitting branches to the arm. However, some studies reported that the ulnar nerve could supply the medial head of triceps brachii muscle. The main objective in this study was identifying the presence of ulnar nerve branches in triceps brachii muscle. Sixty upper limbs of adult Brazilian corpses of both sexes were used. The estimated age was between 25 and 80 years old. Every studied piece had the nerves and their branches quantified and measured with a manual mechanic caliper. The branches were photographed and had the data registered in individual files. Were found ulnar nerve branches for all the heads of triceps brachii muscle: 1 branch (9,1%) to lateral head, 2 branches (18,1%) to long head and 8 branches (72,7%) to medial head. Thus, we can conclude that the contribution of ulnar nerve to triceps brachii muscle constitutes an important anatomical variation.Key words: Ulnar nerve; Triceps brachii muscle; Innervation.
View
... Some series reported ulnar nerve innervating the triceps muscles. [12,13] One must be aware of these variations in the nerve innervations to LHT. The LHT muscle is an embryological derivative of "dorsal muscle mass." ...
Traumatic Partial Posterior Cord Brachial Plexus Injury in a Patient with Aberrant Innervation of the Long Head of the Triceps by the Axillary Nerve: Implications in Nerve Transfer Surgery
Article
Full-text available
  • May 2020
Brachial plexus repair forms an unmet need in terms of posttraumatic rehabilitation, especially the young population, wherein the incidence of accidents is high. This leads to a decrease in the number of functionally active years after the accident. We encountered an interesting case of posttraumatic posterior cord injury predominantly affecting the shoulder abduction beyond 15°. An electrodiagnostic study showed a complete lack of conduction within the axillary nerve with reduced conduction velocity in the radial nerve. We took the patient up for the long head of the triceps transfer to the anterior division of the axillary nerve transfer. Intraoperatively, we found that the long head branch was originating from the axillary nerve at the point of division. As it could not be used for neurotization, we transferred the medial head branch of the radial nerve to the axillary nerve. The patient started to show electroclinical improvement after 3 months of the surgery. A few similar cases have been published, as a cadaveric finding. We report this case to highlight the possibility and need for a high clinical suspicion and also to provide a possible treatment option, in such aberrant anatomy.
View
Surgical Anatomy of the Distal Triceps Tendon
Chapter
  • Jan 2022
Surgical anatomy of the triceps is useful in several routine procedures that involve the distal tendon and olecranon (triceps ruptures, olecranon internal fixation, total elbow arthroplasty, posterior olecranon graft for coronoid reconstruction, and posterior compartment arthroscopy). The long and lateral heads form the tendon proper that inserts in a specific area on the olecranon. Ventral to the tendon proper we find the medial muscular head of the triceps and the capsule, and these attach on distinct insertional areas on the olecranon. The total area of the footprint is approximately 4 cm², and additionally, there is a bare area that extends from the articular side of the olecranon to the posterior capsule. This chapter presents detailed anatomical aspects of the triceps tendon insertion and its relationship with adjacent structures.
View
Brachialis Muscle Transfer to the Forearm Muscles in Obstetric Brachial Plexus Palsy
Article
Full-text available
Tendon transfers are frequently needed to improve hand function in obstetric brachial plexus injuries. The reconstruction cannot always be achieved using local donor transfers in the forearm as these are not always available. In such cases, we propose the use of the brachialis muscle as a useful donor for transfer. Five adolescents with obstetric brachial plexus palsy were operated on to reconstruct wrist extension and/or pronation using the brachialis muscle transfer to the pronator teres (n=1), extensor carpi radialis brevis (n=1) and extensor carpi radialis longus (n=3). Twelve months after surgery, average active motion recovery was 20 degrees for wrist extension and 14 degrees for pronation. Active and passive range of motion was similar.
View
Course of the innervation supply of medial head of triceps muscle and anconeus muscle at the posterior aspect of humerus (anatomical study)
Article
Full-text available
  • Nov 2006
In elbow surgery; posterior side of joint has been described as the front door for accessing the elbow pathologies. Triceps splitting, triceps reflection, posterolateral Kocher, posteromedial Bryan-Morrey, modified MacAusland transolecranon approaches are the well known posterior surgical approaches. In the English literature, release and transposition of ulnar nerve on the medial side was fully described in posterior approaches. We believe that there was a need to identify the structures at the lateral aspect of the elbow while an iatrogenic injury may inversely effect an excellent radiological result. Therefore, we exposed the detailed innervation supply to the anconeus muscle and medial head of triceps muscle and tried to show possible denervation sites of these two structures during posterior approaches. This study was performed on 14 elbows in formalin-preserved 7 cadavers. We exposed the course of the innervation supply to the medial head of triceps muscle and anconeus muscle and tried to show possible denervation sites of these two structures during posterior approaches. The branching pattern of radial nerve innervating anconeus muscle and its deriving level from radial nerve was identified. Distance from a vertical line which is passing through lateral epicondyle to branching point was measured. The mean distance of the branching point of the nerve to medial head of triceps muscle and anconeus was 168.3 mm (range 130.36-185.4). The nerve to anconeus muscle ran along the posterior aspect of the humerus from the horizontal line passing through lateral epicondyle at a distance of 142.20 mm (range 153.72-136.41) medial to olecranon and at a distance of 47.45 mm (range 77.13-30.14) lateral to olecranon. Although splitting the fibers of triceps proximaly increases the exposure of the posterior humerus, innervation of the lateral portion of the medial head of triceps muscle and anconeus muscle may be jeoparadized. Therefore, surgeons who have interest in elbow surgery; (1) should revise the course of the nerve to medial head of triceps and anconeus muscle, (2) be aware of possible iatrogenic injury of the extensor muscles of the elbow via transtricipital approaches, (3) try to choose a more conservative posterior surgical approach.
View
View
View
View
The Surgical Anatomy of the Radial Nerve Around the Humerus
Article
  • Dec 1995
Twenty-four cadaveric arms were dissected to determine the position of the radial nerve on the posterior aspect of the humerus relative to the posterior tip of the acromion, the medial and lateral epicondyles, the division between the lateral and long heads of the triceps, and the triceps aponeurosis. The radial nerve passed anterior to the long head of triceps and cross onto the posterior shaft of the humerus an average of 124 mm below the posterior tip of the acromion. It was never closer than 97 mm. The nerve usually lies on the medial head of the triceps as it courses posteriorly around the humerus and then leaves the posterior shaft of the humerus an average of 126 mm above the lateral epicondyle and 131 mm above the medial epicondyle. It was never within 100 mm of either epicondyle. The surgeon can use these landmarks as guidelines to avoid the radial nerve during operative intervention on the humerus.
View
Surgical anatomy of the radial nerve in the arm: Practical considerations of the branching patterns to the triceps brachii
Article
  • May 1996
Thirty-three cadaveric dissections were performed to identify radial nerve branching patterns to the triceps brachii. Radial innervation of the long head of the triceps originated in the axilla in 88% of the cases and the brachio-axillary angle in 12%. Innervation of the medial head of the triceps originated in the spiral groove in 52% of the cases, the brachio-axillary angle in 39%, and the axilla in 9%. The lateral head was innervated by branches arising in the spiral groove in 70% of the cases, the brachio-axillary angle in 24%, and the axilla in 6%. On average, the radial nerve crossed the midline in the proximal 45% of the arm, 3 cm superior to the level of the deltoid insertion. An intramuscular tendon was present in the medial head of the triceps. The tendon, located medial to the midline of the arm, was seen in all specimens. This tendon serves as an interneural plane with nerve branches descending on either side, but never crossing from one side to the other. Due to the complexity of radial nerve branching, this tendon may be used as a reference plane for longitudinal splitting of the medial head minimizing the risk of nerve damage.
View
Alternative Operative Exposures of the Posterior Aspect of the Humeral Diaphysis. With Reference to the Radial Nerve*
Article
  • Dec 1996
An anatomical study was performed to define the course of the radial nerve in the posterior aspect of the arm, with particular reference to its relationship to operative exposures of the posterior aspect of the humeral diaphysis. In ten cadaveric specimens, the radial nerve was found to cross the posterior aspect of the humerus from an average of 20.7 +/- 1.2 centimeters proximal to the medial epicondyle to 14.2 +/- 0.6 centimeters proximal to the lateral epicondyle. As it crossed the posterior aspect of the humerus in each specimen, the nerve had several branches to the lateral head of the triceps; however, no branches were found innervating the medial head of the triceps in the posterior aspect of any of the specimens. At the lateral aspect of the humerus, the nerve trifurcated into a branch to the medial head of the triceps, the lower lateral brachial cutaneous nerve, and the continuation of the radial nerve into the distal part of the upper arm and the forearm. Three operative approaches were performed in each specimen. The posterior triceps-splitting approach exposed an average of 15.4 +/- 0.8 centimeters of the humerus from the lateral epicondyle to the point at which the radial nerve crossed the posterior aspect of the humerus. For the second approach, the radial nerve was mobilized proximally to allow an additional six centimeters of the humeral diaphysis to be visualized. The third approach (the modified posterior approach) involved the identification of the radial nerve distally as it crossed the lateral aspect of the humerus, followed by reflection of both the lateral and the medial heads of the triceps medially. This exposure permitted visualization of 26.2 +/- 0.4 centimeters of the humeral diaphysis from the lateral epicondyle proximally. The results after use of the modified posterior approach in seven patients were also reviewed.
View
Nerve transfer to deltoid muscle using the nerve to the long head of the triceps, part I: An anatomic feasibility study
Article
To experimentally evaluate the feasibility of restoring the motor function of the deltoid muscle in patients with complete C5-C6 root injury (upper brachial plexus injury) by transferring the nerve to the long head of the triceps to the anterior branch of the axillary nerve through a posterior approach. The study was performed on shoulder girdles of 36 formalin-embalmed cadavers. The number, diameter, and length of the branches of the axillary nerve at the level of the quadrilateral space were noted. The length and diameter of the nerves to the long head and to the lateral head of triceps at the level of triangular space were recorded. The distances from the acromion angle to the bifurcation of the anterior branch of the axillary nerve, to the origins of the nerve to the long head, and to the origin of the lateral head of the triceps were recorded as well. Nerve biopsy specimens of the axillary nerve and the nerve to the long head of the triceps were obtained from 6 fresh cadavers for histomorphometric evaluation. The average length of the anterior branch of the axillary nerve in this study, measured from the quadrilateral space to the innervating site, was 44.5 mm (range, 26-62 mm), and the average length of the nerve to the long head of triceps, measured from its origin to the innervating site, was 68.5 mm (range, 30-69 mm). The average diameter of the anterior branches of the axillary nerve and the nerve to the long head of the triceps were 2.1 and 1.1 mm, respectively. The average number of axon fibers in the anterior branch of the axillary nerve was 2,704 and in the nerve to the long head of the triceps was 1,233. Using the acromial angle as the landmark, the combined length of the two 2 nerves was longer than the distance between them. The diameter, the number of axons, and the anatomic proximity of the nerve to the long head of the triceps make it a potential source for reinnervation of the anterior branch of the axillary nerve by direct nerve transfer without nerve grafting through posterior approach for the management of upper brachial plexus injuries.
View
View