A cadaveric study on four specimens was performed to demonstrate the movements of the distal biceps tendon during passive prono-supination of the forearm (Fig.
9,
Fig.
10,
Fig.
11,
Fig.
12),
before and after the creation of partial (50%) and complete (100%) tears of the tendon,
with integrity of the lacertus fibrosus.
15 patients,
including 4 patients with a complete tendon tear,
1 patient with a partial tendon tear and 10 normal tendons were studied independently by two observers.
Before the examination following a conventional technique,
the dynamic passive prono-supination manoeuvre was performed while the tendon was examined in the transverse plane by the observers,
blinded to the final diagnosis.
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FUNCTIONS OF THE BICEPS BRACHII
•Elbow flexion• Forearm supination• Raising the elbow above the shoulder
Fig. 15: Anatomical Characteristics of the Distal Biceps Tendon
Dynamic passive prono-supination manoeuvre performed in the transverse plane .
Fig. 16: New Maneuver with Pronation/Supination Movements
Fig. 25: Video showing the New Maneuver with Pronation/Supination Movements
TENDON TEARS
•The mechanism involves eccentric contraction against resistance
•Complete tears of the distal biceps are thought to be much more common than partial tears
•Tearing of the Lacertus Fibrosus allows proximal retraction of the biceps
•In cases where the lacertus fibrosus remains intact,
there is minimal retraction of the muscle and clinical diagnosis can be difficult•Tendinosis,
partial tears and complete tears without retraction; ultrasound diagnosis can be challeging
Fig. 18: Images showing:
A) Normal biceps tendon (*). Normal Lacertus fibrosus normal(º)
B) 50% tear of the biceps tendon(*). Lacertus fibrosus normal(º)
C) Complete rupture of the biceps tendon(*) and Lacertus fibrosus(º