Objective: This study reports clinical outcomes of 23 primary total knee arthroplasty (TKA) patients with autogenous morselized bone graft for a large (≥10 mm deep) medial tibial defect, which are usually treated with metal augmentation.

Methods: A total of 23 TKA patients (20 varus knee osteoarthritis and two osteonecrosis of the medial tibial plateau) were followed up for a mean period of five years (range: 2-10.25 years). Patients were evaluated using a disease-specific and patient-derived quality of life measure, the Japanese Knee Osteoarthritis Measure (JKOM), the Knee Society score (KSS), the Timed Up and Go (TUG) test, and knee range of motion (flexion and flexion contracture), respectively.

Bone grafting technique: The mean defect depth was 12.7 mm (range: 10-21 mm). Multiple drill holes were made in the sclerotic floor of the defect followed by impaction of morselized cancellous bone graft to fill it. The tibial component was fixed using bone cement and no internal fixation devices were used. Stem extension of the tibial component was only used in two TKA cases.

Results: Radiographs revealed that the grafted bone was successfully incorporated into the host bone within one year postoperatively. Absorption or collapse of the grafted bone was not detected in any patients. The JKOM, total, knee, and function scores in KSS, TUG test, and flexion contracture showed significant improvements postoperatively. All evaluated items, including flexion of the knee, were comparative to previously reported 78 staged bilateral TKAs.

Conclusion: The autogenous morselized bone graft technique resulted in good radiological and clinical outcomes with several advantages: 1) bone preservation as much as possible, 2) cost effective and simple as it does not require metal augmentation or internal fixation devices, and 3) it can be used for any defect with a depth ≥3 mm.