Preliminary results of managing large medial tibial defects in primary total knee arthroplasty: autogenous morcellised bone graft.

Purpose: This study reports a case series of 44 primary total knee arthroplasties (TKAs) using autogenous morcellised bone grafting for large (≥10-mm-deep) medial tibial defects, which are generally repaired using metal augmentation. The bone-grafting technique is described in detail and the radiological outcomes are presented.

Methods: A total of 44 TKAs were followed up for a mean period of 58 months (range 24-139 months). Multiple drill holes were made in the sclerotic floor of the defect, followed by the impaction of morcellised cancellous bone grafts to fill the defects. Tibial components were fixed using the cemented or noncemented technique and no internal fixation devices were used. Stem extension of the tibial component was only used in one TKA.

Results: Radiograms revealed that the grafted bone was completely incorporated into the host bone within one year post-operatively. No grafted bone absorption or collapse was detected. A clear zone between the tibial component and grafted bone was observed in six knees, but it did not become enlarged thereafter.

Conclusions: The presented technique provided favourable radiological outcomes and had several advantages: (1) it enables preservation of as much bone as possible for future revision surgery; (2) it is cost effective and simple because metal augments, internal fixation devices and stem extension are not needed; (3) it can be used in the same manner any defect to a depth ≥3 mm. Thus, this is an acceptable and reproducible alternative technique.