Table 2.

Osteochondral Autograft Transfer System Procedure: Pearls and Pitfalls

Pearls	Pitfalls
Ideally, bleeding healthy bone should be encountered while reaming the defect. However, it should not exceed 7-8 mm of depth. Frequently check the calibrated coring reamer to avoid over-reaming.	Not addressing concomitant malalignment, ligament instabilities or meniscal issues prior to the transplant can lead to poor result.
Using a smooth dilator after reaming the defect facilitates further insertion of the donor plug.	Heat necrosis can occur from high-speed reamers in the edges of the receptor's bed as well as in the donor plug. Copiously irrigate cutting surfaces with room-temperature saline while using reamers and saws to minimize this problem.
Reduce the size of the original allograft in order to facilitate its manipulation during osteochondral plug preparation.	When the measured size of the donor plug is already close to the desired size, using a saw to trim it can lead to inadvertent excessive bone loss and destruction of the graft. In this situation, it is preferable to use a manual rasp and check the size frequently.
Use a compass reference (north/south/east/west) for measuring the depth of the receptor's bed and have an assistant outside the surgical field take notes to precisely prepare the donor plug.	Avoid strong hits to the osteochondral plug while press-fitting it into the receptor's bed (use a sponge to cushion the chondral surface). Chondrocytes are sensitive to trauma. This could reduce the population of live cells and consequently the quality of the graft.
Submitting the subchondral bone to pulse lavage reduces the bone marrow elements and ultimately the chance of immune reaction	Noncompliance with the postoperative rehab can lead to poor results. Clearly disclose to your patient all the necessary cares (specially restrictions for weight bearing and the use of a continuous passive-motion device) before indicating the procedure.