ABSTRACT
Two years after a quadrupled hamstring anterior cruciate ligament reconstruction using
polylactic acid cross pin femoral fixation, a 32-year-old woman presented with symptoms
of knee catching, locking, and stiffness. Diagnostic arthroscopy revealed a loose
body in the anterior compartment of the knee which was determined to be part of the
polylactic acid femoral fixation pin. The graft was intact and well fixed. After simple
arthroscopic removal, the patient returned to full activities and resumed normal function
postoperatively. We speculate that the fixation pins may have entered the notch and
later degraded or fractured. Using axial magnetic resonance images, we provide preliminary
data suggesting that pins angled posterior to the epicondylar axis may violate the
notch. If pins are to be placed posterior to the epicondylar axis, maximum pin length
can be estimated by the formula: 0.4 × the interepicondylar distance.
