Objective: To assess the early results of the TC3 total knee prosthesis, a modular system with stems and augments, in difficult primary and revision knee arthroplasties.

Method: 13 index procedures were undertaken for gross varus or valgus deformities with severe ligamentous incompetence and/or major bone defects. 18 procedures were revision arthroplasties, 7 being undertaken for sepsis.

29 knees underwent full clinical and radiological review, using the Hospital for Special Surgery Score (HSS) and the Knee Society Score.

One patient was interviewed by phone with recent radiological follow-up. One patient died of unrelated causes.

Results: All patients were very pleased with the outcome of surgery. The mean pre-operative alignment for primary arthroplastles was 280 of varus and 320 valgus. The mean post-operative alignment was 70 valgus. The mean post-operative HSS was 72.4 for primary procedures and 72.7 for revision surgery. The mean Knee Society Knee Score was 77.9 for primary and 75.1 for revision surgery, and the mean function score was 60.8 for primary and 49.4 for revision surgery. The latter reflects the elderly age, multiple joint involvement and constitutional status (including rheumatoid arthritis) of many of these patients.

Conclusion: The TC3 knee system affords an excellent modular option to compensate for bone defects and ligamentous incompetence, achieving restoration of the joint line and satisfactory function in a very disabled group of patients.