Surface morphology of osteochondral grafts harvested from femoral condyles with free-hand technique: a cadaveric study.

PURPOSE: The purpose of this cadaver study was to examine the surface morphology of the osteochondral grafts harvested from the femoral condyles using the free-hand graft harvesting technique.

MATERIALS AND METHODS: One hundred osteochondral grafts were harvested with 6.5 mm chisels at ten different donor sites using the free-hand technique in five paired knee specimens (Mean age: 56.4 years). The cartilage and subchondral bone surface angles were measured through multiplanar reconstruction computerized tomography examination. The cartilage thickness was measured with a MicroScribe G2X digitizer with an accuracy of 0.02 mm. An acceptable congruity could be obtained when these plugs were transferred to a perpendicular socket (articular step-off of less than 1 mm and 0.5 mm) was evaluated.

RESULTS: Four plugs were damaged or broken during harvesting due to technical difficulties; thus remaining 96 plugs were analyzed. The cartilage thickness varied between 1.36 mm and 3.26 mm across the donor sites. The cartilage was the thinnest in the medial intercondylar notch and thickest in the lateral supracondylar notch. Twenty of ninety-six plugs (20.8%) had unacceptable cartilage surface inclination according to the > 0.5 mm protrusion criteria. Of these plugs, 14 were harvested from the lateral intercondylar notch, whereas five of 96 plugs (5.2%) had unacceptable cartilage surface inclination according to the > 1 mm protrusion criteria. Of these plugs, all were harvested from the lateral intercondylar notch.

CONCLUSIONS: High rates of unacceptable plugs (up to 100%) might be harvested from the lateral intercondylar notch. In large chondral lesions that require multiple plugs, lateral and medial supracondylar ridges were the best donor sites for perpendicular plug harvesting, whereas lateral intercondylar notch should be avoided.