Abstract
Large osteochondral allograft (OCA) transplant has become a valid alternative to restore
articular surface in challenging articular lesions in young and active patients, either
in primary or in revision procedures. Several studies support the effectiveness and
safety of OCA, but costs and graft availability limit their use. The indications are
the treatment of symptomatic full-thickness cartilage lesions greater than 3 cm2, deep lesions with subchondral damage, or revision procedures when a previous treatment
has failed. The goal of the transplant is to restore the articular surface with a
biological implant, allow return to daily/sports activities, relieve symptoms, and
delay knee arthroplasty. Grafts can be fresh, fresh-frozen, or cryopreserved; these
different storage procedures significantly affect cell viability, immunogenicity,
and duration of the storage. Dowel and shell technique are the two most commonly used
procedures for OCA transplantation. While most cartilage lesions can be treated with
the dowel technique, large and/or geometrically irregular lesions should be treated
with the shell technique. OCA transplantation for the knee has demonstrated reliable
mid- to long-term results in terms of graft survival and patient satisfaction. Best
results are reported: in unipolar lesions, in patients younger than 30 years, in traumatic
lesions and when the treatment is performed within 12 months from the onset of symptoms.
Keywords
knee - chondral lesion - osteochondral lesion - allograft - osteochondral allograft
