Tibial tubercle osteotomy for access in lateral unicompartmental knee replacement

This paper reports on 27 patients (23 female) with lateral compartment osteoarthritis who underwent lateral unicompartmental knee replacement with the HLS prosthesis using a planned lateral approach elevating the tibial tubercle on a medial periosteal hinge. The patients were followed up for an average of 18 months (range 12–27 months). There were no tibial tubercle non-unions. There were no major complications. One patient died in the follow-up period of unrelated causes. Pre-operative alignment changed from a mean valgus of 12° (4–20°) to 5° (10° to −5°) post-operatively. Pre-operative range of flexion averaged 4–120°. Post-operatively, it was 1–125°. The pre-operative Guepar score was four good, 13 fair, and 10 bad. Post-operative Guepar score was 13 very good, nine good, and five fair. These differences were significant. The post-operative International Knee Society Score averaged 87 (range 74–100). Subjectively, 18 patients were very satisfied, seven were satisfied, one was disappointed and one was dissatisfied. It was concluded that elevation of the tibial tubercle was a safe operation that allowed better access to the lateral compartment for accurate placement of a unicompartmental prosthesis.