Lateral tibial plateau autograft in revision surgery for failed medial unicompartmental knee arthroplasty.

Purpose: Revision surgery for failed unicompartmental knee arthroplasty (UKA) with bone loss is challenging. Several options are available including cement augmentation, metal augmentation, and bone grafting. The aim of the present study was to describe a surgical technique for lateral tibial plateau autografting and report mid-term outcomes.

Methods: Eleven consecutive patients (median age 69.5 years) affected by posteromedial tibial plateau collapse after medial UKA were enrolled in the present study. The delay between UKA and revision surgery was 21 months (range 15-36 months). All patients were revised with a cemented posterior-stabilized implant, with a tibial stem. Medial tibial plateau bone loss was treated with an autologous lateral tibial plateau bone graft secured with two absorbable screws. All patients were evaluated with the Oxford Knee Score (OKS), visual analogue scale for pain (VAS), and complete radiographic evaluation.

Results: At a median follow-up of 60 months (range 36-84 months), the OKS improved from 21.5 (range 16-26) to 34.5 (range 30-40) (p < 0.01) and the median VAS score improved from 8.0 (range 5-9) to 5.5 (range 3-7) (p < 0.01). No intraoperative complications were recorded. Partial reabsorption of the graft was observed in two cases at final follow-up.

Conclusion: Lateral tibial plateau bone autograft is an alternative to metal wedge or cement augments in the treatment of medial plateau collapse after UKA. Primary fixation of the tibial plateau autograft can be achieved with absorbable screws and a tibial-stemmed implant. Further comparative studies with a larger series may be helpful to draw definitive conclusions.

Level Of Evidence: Case series, Level IV.