The Anatomy and Biomechanics of the Patellar Tendon
O Basso and D P Johnson
Although it has been suggested microscopic ruptures in the central region
of the tendon are the cause of patellar tendonitis, and the patellar tendon
is increasingly used to provide the autogenous graft for the reconstruction
of the anterior cruciate ligament, little is known of the detailed anatomy
or biomechanics of the tendon. Therefore a detailed description of the
cadaveric anatomy of the patella tendon and an investigation into the
biomechanics and functional behaviour of the tendon was undertaken.
Ten specimens of cadaveric human knee joints were dissected and the anatomical
parameters measured. The macroscopic appearance of the anterior and posterior
aspect of the patella tendon were assessed and photographed. The origin,
insertion and orientation of the Patella Tendon fibres was described and
mapped in detail. In a further five knee specimens the functional biomechanics
were analysed by measuring the length changes of tendon during eccentric
loading of the instrumented specimens on a test rig using Linear Variable
Displacement Transducers (LVDT).
Additional experiments included analysing the tension generated within
the tendon during functional loading of the knee specimens within the
test rig using specially manufactured buckle strain transducers. The anatomical
findings and the biomechanical behaviour of the tendon was related to
the local surgical pathology and related to the technique of surgically
harvesting the patellar tendon graft from the tendon.