Download Case report Analysis of bony bridge over bicipital groove

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Anatomy
Case report
Analysis of bony bridge over bicipital groove
Abstract
Introduction
Bicipital groove or intertubercular
sulcus is bounded by lesser tubercle
medially and greater tubercle laterally. The contents of this groove are
long head of biceps brachii, synovial
sheath and ascending branch of anterior circumflex humeral artery. The
groove is bridged by transverse
humeral ligament. This ligament has
been found to be ossified. This
osseous tissue may damage the
contents of bicipital groove during
biomechanical movements of the
arm. The ossification of this ligament
is a new discovery known to the
author and bears clinical implications. Hence the study has been
carried out.
Case report
During examination of bones in the
osteology lab in the Department of
Anatomy, we came across a rightsided humerus showing complete
ossification of the transverse
humeral ligament. The incidence is
1%. This osseous bridge extended
from the lateral margin of the lesser
tubercle to the medial margin of the
greater tubercle. The horizontal,
vertical lengths and thickness of the
ossified ligament were 7, 5 and 2 mm,
respectively.
Discussion
The ossified ligament may cause tendinitis of the long head of biceps brachii
leading to anterior shoulder pain. It
may also cause tenosynovities.
Conclusion
Knowledge of the ossified transverse
humeral ligament may be of immense
* Corresponding author
Email: [email protected]
Department of Anatomy, AIIMS, Virbhadra
Marg, Pashulok, Rishikesh, Uttrakhand, India
use to clinicians for anterior
shoulder pain. It may also cause
misinterpretation of radiographs.
Introduction
The proximal part of the humerus
consists of head, greater tubercle,
lesser tubercle and bicipital groove.
The head is medially directed, greater
tubercle is situated on the lateral
aspect and lesser tubercle on the anterior aspect of the proximal part of the
humerus. Bicipital groove lies between
the lesser and the greater tubercles.
This groove is bridged by the transverse humeral ligament as described
in the standard text books of anatomy
but the existence of this ligament has
been doubted by MacDonald et al.1
and Gleason et al.2 and replaced by
muscle fibres. The groove is occupied
by a long head of biceps tendon
surrounded by synovial sheath and
ascending branch of the anterior
circumflex humeral artery. A bony
bridge has been observed over the
bicipital groove in a humerus. The
complete ossification of the transverse
humeral ligament or muscle fibres is
being reported for the first time.
Therefore, it amounts to new variants.
This osseous bridge may cause
tenosynovitis and tendinitis leading
to anterior shoulder pain and may
complicate other surgical interventions around this region. Thus, knowledge of this variant may be of utmost
use to orthopaedic surgeons, physicians, radiologists and anatomists.
This paper analyses the bony bridge
over the bicipital groove.
Case report
During examination of bones in the
osteology lab of the Department of
Anatomy, a right-sided humerus was
found showing complete ossification
of the transverse humeral ligament or
muscle fibres of the muscles (Figure 1)
situated in the vicinity of this bridge.
The length, breadth and thickness of
the osseous tissue were taken with
Figure 1: Ossified transverse humeral ligament in antero-superior view of
upper end humerus. Probe is in the canal formed by this ossified ligament.
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)
For citation purposes: Singh R. Analysis of bony bridge over bicipital groove. OA Case Reports 2013 Oct 21;2(13):124.
Competing interests: none declared. Conflict of interests: none declared.
All authors contributed to the conception, design, and preparation of the manuscript, as well as read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
R Singh*
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digital vernier calipers. The photographs were taken, and clinical implications and causes of ossification
were analysed.
The bridge extended from the
lateral margin of the lesser tubercle
to the medial margin of the greater
tubercle. The horizontal, vertical
lengths and thickness of ossified ligament/fibres were 7, 5 and 2 mm,
respectively. The incidence of this
bony bridge formation over bicipital
groove was 1%. There was no other
abnormality in the humerus.
Discussion
The bicipital groove is bridged by the
transverse humeral ligament or
muscle fibres of subscapularis and
supraspinatus muscles and pectoralis major muscle. MacDonald et al.1
observed that what is defined as
transverse humeral ligament is not
ligament as described in standard
text books rather this is a fibrous
expansion arising from the posterior
lamina of the tendon of pectoralis
major overlying the long tendon of
biceps in every shoulder of all the 85
shoulders. In 86% of shoulders,
fibres from the tendon of subscapularis passed over the long tendon of
biceps within this fibrous expansion
and inserted on to the greater
tubercle of the humerus. According
to Gleason et al.2, there is no identifiable transverse humeral ligament,
rather the fibres covering the intertubercular groove are composed of a
sling formed mainly by the fibres of
the subscapularis tendon, with
contributions from the supraspinatus
tendon and the coracohumeral ligament. Gleason et al.2 confirmed these
gross dissection patterns of fibre
attachment through histological
studies. This revealed the absence of
elastin fibres, which are more
commonly seen in ligamentous structures and are typically absent from
tendinous structures. These studies
reveal that the bridging seen over
bicipital groove cover the muscle
fibres rather than ligament.
Causes of formation of
bony bridge
As the bony bridge was detected in
one right-sided humerus out of 100
humeri examined, it is pertinent here
to analyse the causes of this bony
structure. Partial or complete calcification and ossification of superior
transverse scapular ligament3 and
transverse acetabular ligament4 have
been documented. Standard text
books do not describe the ossification
of transverse humeral ligament/
muscle fibres and no literature is
available on the theory of causes of
osseous bridging over bicipital
groove. In such a situation, the author
attempted to formulate a logical basis
for ossification of the tissues bridging
the bicipital groove. One of the possibilities of calcification may be calcium
metabolism disorder in such persons.
Cohen et al.5 described a familial case
of calcification of superior transverse
scapular ligament affecting a 58-yearold man and his son who had calcification of superior transverse scapular ligament causing entrapment
neuropathy of the suprascapular
nerve and its attendant clinical symptoms of pain, weakness, atrophy of
the supraspinatus muscle. Similarly,
calcification and ossification of transverse humeral ligament/muscle
fibres may be due to genetic reasons
which are to be confirmed by further
clinical studies.
Formation of bony bridge over the
bicipital groove may also be caused
by repetitive strain on the subscapularis, supraspinatus muscles and
pectoralis major muscle resulting in
microtrauma during biomechanical
movements of the shoulder and ultimately leading to calcification and
ossification of these fibres.
Clinical significance
It was observed in 1% of subject
population. These muscle fibres
prevent subluxation of tendons of
the long head of biceps during
biomechanical movements of the
arm ensuring soft stability of the
tendon. In movements from external
rotation to internal rotation, the
tendon is forced medially against
lesser tubercle and superiorly
against transverse humeral ligament6 during biomechanical movements of the arm, the long tendon of
biceps rub against the overlying
muscle fibres. As muscle fibres are
soft tissues these structures do not
damage the tendon during biomechanical movements of the arm. But
when these muscle fibres are ossified, the tendon of biceps brachii
constantly rub against the bony
bridge during movements like repetitive lifting of weight, stretching of
arm vertically during exercise,
various multidirectional movements
in wrestling and in picking up
objects from higher places by lifting
the arm. This rubbing may lead to
inflammation, microtearing and if
untreated, it will cause degenerative
changes in the tendon of the biceps.
An inflamed tendon may lead to
anterior shoulder pain. Frequent or
repetitive lifting, in case of chronically inflamed tendon of biceps
brachii, can lead to spontaneous
rupture. The patient complaining of
anterior shoulder pain aggravated
by lifting activities like carrying
objects, shopping bags and reaching
overhead objects may invite attention of the clinician towards the
above complications. Thus anterior
shoulder pain may be caused by
bony bridge. A dramatic worsening
of symptoms and description of a
lump just above the antecubital
fossa suggests an acute long head
tendon rupture. It may also cause
thrombosis of the ascending branch
of the anterior circumflex humeral
artery running in the bicipital groove
creating ischaemia in the structures
supplied by this artery.
Bicipital groove is often used as an
important landmark for proper
orientation of humeral prosthesis,
especially in the case of a fracture7.
The bicipital groove is also used as an
anatomic landmark to restore
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)
For citation purposes: Singh R. Analysis of bony bridge over bicipital groove. OA Case Reports 2013 Oct 21;2(13):124.
Competing interests: none declared. Conflict of interests: none declared.
All authors contributed to the conception, design, and preparation of the manuscript, as well as read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
Case report
Page 3 of 3
humeral head retroversion when
treating complex proximal humeral
fractures with arthroplasty8. The
bicipital groove offers a useful landmark for placement of lateral fin of
the prosthesis9. In the presence of
ossified transverse humeral ligament/muscle fibres, this groove may
not act as a useful landmark for the
above procedures. The ossified fibres
may cause misinterpretation of
­
radiographs.
Thus knowledge of ossification of
transverse humeral ligament/muscle
fibres may be of paramount importance to physicians for anterior
shoulder pain, orthopaedic surgeons
for deciding bicipital groove as landmarks in different types of shoulder
surgery, radiologists for avoiding
misinterpretation of radiographs and
anatomists for new variants.
Conclusion
• Osseous bridge over bicipital groove
may be formed by ­ossification/calcification of transverse humeral ­ligament/
muscle fibres.
• The ossified bridge may cause
anterior shoulder pain.
• The ossified bridge may obscure
the radiological image of the bicipital groove.
• Due to presence of the osseous
bridge, the bicipital groove may not
act as a landmark to locate the
position of surgical procedures in
and around the bicipital groove.
References
1. MacDonald K, Bridger J, Cash C, Parkin
I. Transverse humeral ligament: does it
exist? Clin Anat. 2007 Aug;20(6):
663–7.
2. Gleason PD, Beall DP, Sanders TG, Bond
JL, Ly JQ, Holland LL, et al. The transverse
humeral ligament: a separate anatomical
structure or a continuation of the osseous
attachment of the rotator cuff? Am J
Sports Med. 2006 Jan;34(1):72–7.
3. Ticker JB, Diurasovi CM, Strauch RJ,
April EW, Pollock RG, Flatow EL, et al.
The incidence of ganglion cysts and
other variations in anatomy along the
course of the suprascapular nerve. J
Shoulder Elbow Surg. 1998 Sep–Oct;
7(5):472–8.
4. Bhanu Sharmila P, Shankar KD. Bilateral ankylosis of sacroiliac joint with ossification of sacrospinous, sacrotuberous
and transverse acetabular ligaments. IJAV.
2011 Jan;4:123–7.
5. Cohen SB, Dnes DM, Moorman CT.
Familial calcification of the superior
transverse scapular ligament causing
neuropathy. Clin Orthop Rel Res. 1997
Jan;334:131–5.
6. Standring S, editor. Grays anatomy: the
anatomical basis of clinical Practice. 39th
ed. Spain: Churchil Livingstone; 2006.
p823–32.
7. Kontakis GM1, Damilakis J, Christoforakis J, Papadakis A, Katonis P,
­Prassopoulos P. The bicipital groove as a
landmark for orientation of the humeral
prosthesis in cases of fracture. J Shoulder
Elbow Surg. 2001 Mar–Apr;10(2):136–9.
8. Anqibband L, Zuckerman JD, Flurin
PH, Roche C, Wright T. Reconstructing
proximal humeral fractures using the
bicipital groove as a landmark. Clin
Orthop Relat Res. 2007 May;458:168–74.
9. Itamura J, Dietrick T, Roidis N, Shean C,
Chen F, Tibone J. Analysis of the bicipital
groove for humeral head replacement. J
Shoulder Elbow Surg. 2002 Jul–Aug;
11(4):322–6.
Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)
For citation purposes: Singh R. Analysis of bony bridge over bicipital groove. OA Case Reports 2013 Oct 21;2(13):124.
Competing interests: none declared. Conflict of interests: none declared.
All authors contributed to the conception, design, and preparation of the manuscript, as well as read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.
Case report