The Long Head of the Biceps
Tendon:
Normal Anatomy and
Pathology on MRI
Lynne S. Steinbach, M.D.
Professor of Radiology and Orthopaedic Surgery
Department of Radiology
University of California San Francisco
Biceps Muscles
and Tendons
Long Head
Short Head
Distal Tendon
Bicipital Aponeurosis
(Lacertus Fibrosis)
Long Head of the Biceps Tendon
(LHBT)
•
•
•
•
•
Anatomy
Function
Pathology
Variants
Treatment
• Origin
– Superior labrum and/or
supraglenoid tubercle
• Intracapsular, extrasynovial
• Extends laterally in the
rotator interval which is
composed of:
–
–
–
Capsule
Coracohumeral lig (CHL)
Superior glenohumeral lig
(SGHL)
– Supraspinatus(SS)
– Subscapularis (Subs)
LHBT
Origin
• Originates from the
supraglenoid tubercle
and superior labrum
LHBT Intra-articular Portion from
Anchor to Pulley
Sagittal Plane
LHBT Intra-articular Portion from
Anchor to Pulley
Axial Plane
LHBT Origin
Axial Plane
• Glenoid origin is variable between individuals
Anterior origin
Posterior origin
SGHL
Normal LHBT, SGHL, CHL in
Rotator Interval
Axial Plane
L
H
C
B
• Pulley is junction
between intra- and
extra-articular biceps
• Curves 30-45 degrees
into extra-articular
groove
• Notice the Subs tendon
extending over the
pulley to the greater
tuberosity
LHBT
Pulley
• Surrounds biceps in
rotator interval and
proximal biceps groove
• Ligamentous sling
– Superficial-CHL
– Deep-SGHL
• Contributions from SS
and Sub tendons called
fasciculus obliquus
Sagittal plane
LHBT
Pulley
Pulley
Biceps
Notice the split in the biceps
Sagittal plane
LHBT
Pulley
• Extra-articular BT lies
in intertubercular sulcus
between LT and GT
• Stabilized by pulley
– CHL superficial
– SGHL deep
• Pulley reinforced by
Subs and SS tendon
fibers
– Attach to LT and GT
Su
is
r
a
l
u
p
a
bsc
Axial plane
SS
LHBT
Synovial Reflection in
Intertubercular Groove
LHBT
Synovial Reflection in
Intertubercular Groove
LHBT
Function
• Humeral head
depressor
• Stabilizer GHJ
– Posterior translation of
flexed or abducted
externally rotated
shoulder
• Biceps is fixed between
glenoid and humerus
– Superior excursion 4cm
from flexion to extension
LHBT
Sports Injuries
• Occur with repetitive
load and abrasive wear
• Less commonly acute
• Diagnosis and
treatment of biceps
injuries is a clinical
challenge
LHBT
Pathology By Location
• Intra-capsular
– Origin
• Tendon and labral (SLAP) lesions
– Rotator interval
• Impingement (external and internal)
• Subluxation and dislocation
• Tendinosis
– Hourglass biceps
• Tears
• Extra-capsular
– Biceps groove
• Tenosynovitis
Most biceps tendon abnormalities are
• Tendinosis
accompanied by other internal derangement
• Tears
Causes of LHBT Dislocation and
Subluxation
• Trauma and impingement (ASI)
– Forcefully stopped overhead throw
– Repetitive forceful internal rotation above the
horizontal plane
– Fall
• Outstretched arm internal or external rotation
• Backward on hand or elbow
• Biceps groove anomalies and dysplasia
• Degeneration of biceps tendon
• Tears subscapularis and supraspinatus tendons
Anterior Superior Impingement
• Internal impingement caused
by repetitive overhead motion
• Internal rotation and adduction
• Biceps instability and tears
• Anterior translation and
superior migration humeral
head
• Tears
– Pulley lesions SGHL and
CHL
Peter Habermeyer, J Shoulder and Elbow Surg
– SS and Subscap tendons 2004;13:5-12
Phases of Baseball Pitching
Cocking
Follow-through
Phases of baseball pitching
Biceps in Throwing Athletes
• Vector forces on LHBT
– Cocking
• External rotation
• Medial force
– Follow-through
• Internal rotation
• Lateral force
Phases of baseball pitching
• EMG activity increased
with follow-through and
shoulder instability
Biceps Subluxation & Dislocation
Modified Habermayer Classification
Sub
ris
a
l
u
p
sca
SS
• EXTRA-ARTICULAR
– Subluxation
• I and II
– Dislocation
• III and IV
• INTRA-ARTICULAR
– Dislocation
• V and VI
Type I
Biceps Subluxation
Subscapularis Tendon Tear with Intact Pulley
S
a
c
s
ub
ris
a
l
pu
SS
• Intact pulley
• Subscapularis tendon
partial intrasubstance
or anterior tear
• Medial biceps shift or
minor subluxation
Type II
Biceps Subluxation
Medial Pulley Tear with Intact Subscap
Tendon
SS
S
a
c
s
ub
is
r
a
l
pu
Biceps shift or subluxation more exaggerated than Type I
Isolated Pulley Lesion
SGHL Tear/Biceps Tendinitis
sc
b
u
S
Type IIIA
Extra-articular Biceps Dislocation
Medial Pulley and Intrasubstance
Subscapularis Tendon Tears
partial subscap tear.jpg
is
r
a
l
apu
SS
Type IIIB
Extra-articular Biceps Dislocation
Medial Pulley and Anterior Subscapularis
Tendon Tears
c
SS
s
S ub
ris
a
l
u
ap
Type IV
Extra-articular Biceps Dislocation
Lateral Pulley with Supraspinatus Tears
SS
Tear
Type V
Intra-articular Biceps Dislocation
Medial and Lateral Limbs of Pulley and Full
Thickness Subscapularis Tendon Tears
SS
is
r
a
l
pu
a
c
bs
u
S
Su
Type VI
Intra-articular Biceps Dislocation
Medial Pulley and Subscap tendon
Detachment from LT
b
ris
a
l
u
p
a
sc
SS
Type VI
Intra-articular Biceps Dislocation
Medial Pulley and Subscap tendon
Detachment from LT
Armstrong A, et
al. J Shoulder
Elbow Surg
2006;15:7-11
Split Tear Biceps Tendon with
Med Subluxation & Subscap Tear
LHBT Tendinosis
Hourglass Biceps
• BT tendinosis just
proximal to bicipital
groove with tendon
unable to slide into
groove
• Inhibits passive and
active elevation and
causes pain
• Usually seen with RCT
Opsha O, et al., Eur J Radiol 2008;68:36-56
Boileau P, et al. J Shoulder Elbow Surg 2004;13:249-257
*Chung C and Steinbach L., eds.
MRI of the Upper Extremity. LWW, 2009
Hourglass Biceps
Sagittal T2W
Coronal T2W
Biceps Entrapment
“Hourglass Biceps”
Partial Tear LHBT
SS Tendon Tear
SLAP Lesion
Partial Tears LHBT
Partial tear biceps
Complete Tear LHBT Near
Origin at Supraglenoid Tubercle
in a Bodybuilder
Posterior Dislocation of LHBT
with Posterior Incarceration
Incarcerated LHBT in GT Fx
Incarcerated Biceps in Greater
Tuberosity Fracture
Extra-articular LHBT
Tenosynovitis
• Primary
– Repetitive overhead
movement in sports
• Secondary
– Rotator cuff tears
and external
impingement
Criteria for Extra-articular Biceps
Tenosynovitis
• Fluid out of proportion
to that in the joint
• Several bands in
tendon sheath
• Tendon adherence to
one side
Extra-articular Biceps Tendon
Evaluation During Arthroscopy
• Extra-capsular portion not
seen during arthroscopy
• Preoperative knowledge of
pathology leads surgeon to
probe the tendon
– Pulling on intracapsular
tendon improves
visualization of extracapsular portion
Longitudinal Biceps Tear and
Normal Variant in the Groove
Partial Tear
Normal variant-Accessory Head
-
Split Biceps Tendon?
Copyright © 2010 by the American Roentgen Ray Society
-
Accessory Head of LHBT
• Prevalence of
supernumerary head 922%
• More common in
Asians
• Less common in
Caucasians
Gheno, R. et al. Am. J. Roentgenol. 2010;194:W80-W83
Copyright © 2010 by the American Roentgen Ray Society
LHBT Variants
• Accessory heads
– 3-7 heads have been reported
• Congenital absence
• Intracapsular origin
-
Accessory Head of LHBT
• Prevalence of
supernumerary heads
9-22%
• More common in
Asians
• Less common in
Caucasians
Gheno, R. et al. Am. J. Roentgenol. 2010;194:W80-W83
Copyright © 2010 by the American Roentgen Ray Society
Osseous Body in Tendon Sheath
Can Mimic Accessory Tendon
Congenital Absence of the LHBT
• Seven cases reported
– 4/7 associated with
other anomalies
including
•
• Spina bifida occulta
• Congenital inguinal hernia
• Right undescended
testicle
Insult in 6th and 7th
week of gestation
• Underdeveloped biceps
groove
Intracapsular Origin LHBT
• Incomplete
differentiation of
the joint capsule
• Biceps merges
with capsule
LHBT Pathology
Treatment
•
•
Conservative
Debridement
– Partial tears and
tendinosis
• Tenodesis or tenotomy
– Large partial or full
thickness tear or
subluxation
• Repair of adjacent
rotator cuff tear
Biceps Tenodesis
Injuries of the Long Head of the
Biceps Tendon
• Biceps tendon disease is associated with overhead
sports as well as rotator cuff disease and SLAP
lesions
• The pulley, supraspinatus and subscapularis
tendons are often abnormal with displacement and
tears of the biceps tendon
• Intra-articular tendinosis is common
• Extra-articular biceps abnormalities as well as
normal variants are well seen with MR and US