Modular augmentation in revision total knee arthroplasty

Purpose

Controversy exists about the real effectiveness of modular augmentation to manage bone defects in revision total knee arthroplasty. The purpose of this study was to determine whether use of modular augmentation to reconstruct severe defects (1) significantly increased overall outcomes, (2) caused radiolucency or osteolysis and (3) affected mid-term survivorship of knee revisions. The hypothesis was that modular augmentation provides a good survivorship of knee revisions.

Methods

Thirty-eight consecutive revision knee arthroplasties were followed for a median follow-up period of 7 (4.5–9) years. Type 2 and 3 defects were treated with metal augments, tantalum cones and modular cementless stems. Patients were assessed using the IKS knee and function scores and the HSS score.

Results

The median IKS knee and function scores and HSS score were 34 (15–58), 19.5 (13–39) and 30 (24–60) points before the operation, respectively, and 78 (49–97), 76 (58–90) and 80.5 (64–98) points (p < 0.001) at the latest follow-up. The median knee flexion increased from 82° (31°–110°) to 116° (100°–129°) (p < 0.01). Tibial radiolucencies were observed in 2 (5.2 %) cases. Re-revision was necessary in three (7.9 %) patients.

Conclusions

Modular augmentation may reduce the need for allografting to treat severe bone defects, providing a well-functioning and durable knee joint reconstruction.

Level of evidence

Case-series study, Level IV.