Table 3.

Technical Pearls/Pitfalls for MACI Transplantation Augmented With Autologous Bone Graft

Pearls	Pitfalls
It is important to thoroughly debride the cavitary bone defect, including the sclerotic margins. A small k-wire can be used to enhance the blood supply if necessary, and BMAC may be useful to aid in bone graft incorporation and successful healing.	The MACI graft should be positioned flat within the defect. It is important to cut the margins of the graft so that they do not overlap the surrounding articular cartilage surface, because this could predispose the graft to delamination and early failure.
Ensure that enough bone graft is obtained to adequately fill the defect flush to the surrounding subchondral bone.	Pay close attention to the orientation of the MACI graft as it is prepared and positioned within the defect. It is extremely important to ensure that the cellular side of the scaffold is facing down toward the subchondral bone.
Use a sufficient amount of fibrin glue to ensure that the area overlying the bone graft has a watertight seal.
In most cases, fibrin glue provides adequate graft stability, but if there is concern about graft fixation, No. 6-0 resorbable suture can be used to provide additional fixation.

BMAC, bone marrow aspirate concentrate; MACI, matrix-induced autologous chondrocyte implantation.