Download February 2014 Case Study - American Academy of Pediatrics

February 2014 Case Study
Author: Pamela Lachniet, MD, PhD, Cincinnati Children’s Hospital Medical Center
Chief Complaint: Right arm pain
HPI: A 19 y/o previously healthy right hand dominant defensive lineman had the acute onset of right
upper arm pain during a football game. He was performing a tackle when another player fell on his arm
and he felt a pop. Despite the arm pain, he was able to remain in the football game for an additional 3
plays. After coming out of the game he was assessed by the college’s medical staff. He reported diffuse
right upper arm pain and weakness but denied neck pain or numbness. The patient denied use of
anabolic steroids. He was a non-smoker.
Physical Exam:
General Appearance: well appearing, no distress
Skin: mild bruising over distal right upper arm and antecubital area with no lacerations
Cardiovascular: warm, well perfused with 2+ radial pulses bilaterally
Cervical Spine: no midline tenderness, normal ROM, negative Spurling’s sign
Right Arm:
Inspection: visible deformity (Popeye appearance) distal upper arm
Palpation: diffusely tender over mid to distal biceps with palpable defect in antecubital fossa
Range of Motion: pain with elbow flexion, extension, and supination
Strength: elbow flexion 4/5, elbow extension 4/5, supination 2/5, pronation 4/5
Special Tests: negative varus and valgus stress tests; abnormal Hook test (biceps tendon not
palpable in antecubital fossa); positive Speeds test
Left Arm:
Inspection: no deformity
Palpation: non-tender
Range of Motion: full without pain
Strength: elbow flexion 5/5, elbow extension 5/5, supination 5/5, pronation 5/5
Special Tests: negative varus and valgus stress tests; normal Hook test
Differential Diagnosis:
Biceps contusion
Biceps strain
Rupture of long head of biceps
Distal biceps tendon tear, partial or full thickness
Neuropraxia
Burner
Fracture of humerus
Diagnostic Studies:
MRI of Right Upper Arm: Complete retraction of the biceps tendon from the insertion upon the radial
tuberosity. No substantial tendon stump remaining. Brachialis tendon and muscle and triceps tendon
are intact.
Final/Working Diagnosis: Distal biceps tendon rupture, full thickness
Treatment: Sling and NSAIDs for pain control. Surgical repair of biceps tendon was performed 1 week
after injury using a 2-incision technique.
Outcome: The patient followed a graded post-operative rehab program. His strength was noted to
improve and flexion/extension range of motion was normal at his six week post-operative follow up. Xrays were performed at that time due to restriction of supination (10 degrees) and pronation (30
degrees), compared to 90 degrees of supination and pronation on the contralateral arm. The images
showed heterotopic bone formation around the drill holes for the biceps insertion at the proximal radius
with proximal synostosis of the radioulnar joint. A second surgery was performed 14 weeks after the
initial surgical repair to remove the heterotopic bone. Following the second surgery, the patient was
lost to follow up.
Discussion:
Rupture of the biceps tendon is more often seen in the adult population but can also be seen in young
adult athletes as a result of an acute traumatic event. In general, the majority of ruptures are proximal,
involving the long head of the biceps as it originates from the supraglenoid tubercle on the scapula.
Distal biceps tendon ruptures are rare, representing only 3-12% of all biceps tendon injuries. Of those,
the majority avulse from the radial tuberosity where the long head of the biceps inserts rather than
within the substance of the tendon or at the musculotendinous junction.
The mechanism of injury for a distal rupture is typically a sudden extension force applied to a flexed,
supinated forearm which causes a forceful eccentric contraction of the biceps muscle. Patients will
often report an audible pop or snapping sensation followed by pain and weakness. The injury is rare in
the overhead athlete. Athletes more at risk for the injury are involved in weightlifting, football, and
rugby. Additional risk factors that have been identified include male gender, nicotine use, anabolic
steroid use, and body building. The injury occurs in the dominant arm 86% of the time. Tears are
classified as complete (involving the full tendon thickness), partial low grade (<50% of tendon), or partial
high grade (>50% of tendon) and as acute (< 4 weeks from time of injury) or chronic.
On clinical exam there is frequently swelling and ecchymosis in the antecubital fossa in the acute phase.
The forearm may have a “Popeye” appearance with increased prominence in contour as the muscle
belly retracts proximally as well as a defect palpable in the antecubital fossa. The deformity may not be
as pronounced if the bicipital aponeurosis between the two heads of the biceps muscle remains intact.
These findings are variable in partial ruptures as well as in subacute or chronic injuries. Patients will also
have a marked decrease in elbow flexion and supination strength. The biceps is the most powerful
supinator of the forearm, with the long head of the biceps contributing most of the supination force.
The short head of the biceps, originating from the coracoid process and attaching onto the shaft of
radius, is responsible for most of the flexion from the biceps but flexion is also performed in conjunction
with the brachialis muscle so some flexion strength may be preserved.
Additional special clinical tests can be used to assist in the diagnosis of distal biceps tendon rupture. The
biceps squeeze test is analogous to the Thompson test for Achilles tendon rupture. Squeezing the
biceps with an intact tendon should produce passive supination in the flexed and pronated arm.
Absence of passive supination represents an abnormal result. Another test that has shown good
sensitivity and specificity is the hook test which is performed with the patient’s elbow flexed to 90
degrees and isometrically supinated. In that position, the examiner attempts to insert their finger
laterally at the antecubital fossa to detect an intact biceps tendon spanning the fossa in front of the
brachialis. A tendon may be palpated with a partial rupture but the test will elicit pain. The Passive
Forearm Pronation test employs visualization and palpation of the biceps muscle belly moving proximal
to distal as the forearm is rotated passively from full supination to pronation. Although no single test
can reliably diagnose a distal rupture 100% of the time, by combining the different clinical tests a
relatively accurate assessment can be made.
Although the diagnosis of rupture relies more on the history and clinical exam, plain radiographs may
show soft tissue swelling and enlargement or occasionally an avulsion of the radial tuberosity. MRI is
considered the gold standard of imaging to determine the integrity of the tendon and degree of
retraction. The FABS (Flexion, ABduction, Supination) position during imaging allows for full length
views of the tendon. Overall sensitivity and specificity of MRI in detecting distal biceps tendon ruptures
have been found to be 92.4% and 100% respectively. The sensitivity for detecting partial tears is
significantly less, at 59.1%. Ultrasound is also a possible imaging modality for diagnosis. It tends to be
cheaper and more readily available, although the results are less reproducible than MRI.
The recommended treatment of complete distal biceps tendon ruptures is surgical for the active young
athlete who will require a lifetime of adequate supination and flexion strength. Adult patients who opt
for non-operative treatment experience a 50% decrease in supination and 35-40% decrease in flexion
strength as well as prolonged pain. Repair of a partial rupture is more controversial, although high
grade partial tears (>50% of tendon involvement) are generally repaired in a healthy young adult. In
contrast, repair of a proximal rupture of the long head of the biceps is rarely performed as there is little
loss of strength and the defect is mostly cosmetic.
Referral for surgical repair should be made early, within the first few weeks, to avoid scarring down of
the biceps and retraction of the tendon proximally. A delayed repair becomes more difficult and
increases the rate of complications. The surgeon has a number of surgical options but most use a single
incision or double incision technique. The main complication of the single incision technique is injury to
the lateral antebrachial cutaneous nerve causing paresthesias or to the posterior interosseous nerve
causing nerve palsy. Radioulnar synostosis and heterotopic ossification is the main complication
associated with the double incision technique and usually requires a subsequent excision to restore
function. There is some evidence that the prophylactic use of indomethacin may prevent heterotopic
ossification but must be weighed against the risks of NSAID use. The choice of technique often depends
on the skill and comfort level of the surgeon with each approach.
In summary, a distal biceps tendon rupture occurs after a forceful eccentric contraction of the forearm.
Risk factors include male gender, weightlifting, bodybuilding, nicotine and anabolic steroid use. The
history and clinical exam are key to making the diagnosis. Common findings include deformity of the
biceps contour (“Popeye” appearance), pain and weakness with flexion and supination, and abnormal
biceps squeeze test, hook test, and passive forearm pronation test. An MRI may be useful to further
clarify the integrity of the tendon. Early surgical referral is recommended for optimal outcomes with
fewer complications.
References:
McDonald, L. L. S., Dewing, C. C. B., Shupe, L. P. G., & Provencher, C. M. T. (2013). Disorders of the
Proximal and Distal Aspects of the Biceps Muscle. The Journal of Bone & Joint Surgery, 95(13), 12351245.
Devereaux, M. W., & ElMaraghy, A. W. (2013). Improving the Rapid and Reliable Diagnosis of Complete
Distal Biceps Tendon Rupture A Nuanced Approach to the Clinical Examination. The American journal of
sports medicine, 41(9), 1998-2004.
Anakwenze, O. A., Kancherla, V. K., Warrender, W., & Abboud, J. A. (2011). Outcomes of Modified 2incision Technique With Use of Indomethicin in Treatment of Distal Biceps Tendon Rupture. Orthopedics,
34(11), e724-e729.
Bain, G. I., & Durrant, A. W. (2010). Sports-related injuries of the biceps and triceps. Clinics in sports
medicine, 29(4), 555-576.
Miyamoto, R. G., Elser, F., & Millett, P. J. (2010). Distal biceps tendon injuries. The Journal of Bone &
Joint Surgery, 92(11), 2128-2138.
Festa, A., Mulieri, P. J., Newman, J. S., Spitz, D. J., & Leslie, B. M. (2010). Effectiveness of magnetic
resonance imaging in detecting partial and complete distal biceps tendon rupture. The Journal of hand
surgery, 35(1), 77-83.
Kokkalis, Z. T., & Sotereanos, D. G. (2009). Biceps tendon injuries in athletes. Hand Clinics, 25(3), 347357.
O’Driscoll, S. W., Goncalves, L. B., & Dietz, P. (2007). The hook test for distal biceps tendon avulsion.
The American journal of sports medicine, 35(11), 1865-1869.
Ruland, C. R. T., & Bowen, C. J. D. (2005). The biceps squeeze test for diagnosis of distal biceps tendon
ruptures. Clinical orthopaedics and related research, 437, 128-131.
Dahners, L. E., & Mullis, B. H. (2004). Effects of nonsteroidal anti-inflammatory drugs on bone formation
and soft-tissue healing. Journal of the American Academy of Orthopaedic Surgeons, 12(3), 139-143.