Abstract
Introduction The tibial component of a total knee arthroplasty is subjected to eccentric medial and lateral plateau tibial loading during various phases of stance. The resultant coronal planar tilting forces may provoke early subsidence and loosening. The addition of a long non cemented stem is postulated to act as an outrigger, diminishing the rate of aseptic loosening.
Methods Two hundred and thirteen primary total knee arthroplasties using proximally cemented tibial components with long non cemented Pressfit stems have been reviewed. Stem lengths varied from 110 mm to 140 mm. Patients were seen at an average of 8.7 years after surgery (two to 13 years) and were assessed using the Knee Society (IKS) pain and function scores, IKS radiographic analysis and Short Form-12 and Western Ontario Macmasters University Osteoarthritis Index (WOMAC questionnaires).
Results Average range of motion was 115° at latest follow-up. The average IKS pain and function scores at the time of assessment were 90 and 89 respectively. Radiographic assessment revealed no case of tibial implant loosening. Kaplan-Meier survivorship was 98.6% at 13 years.
Conclusions The results lend clinical support to the known theoretical advantages of adding a stem to the tibial component in primary knee arthroplasty.
In relation to the conduct of this study, one or more the authors have received, or are likely to receive direct material benefits.
The abstracts were prepared by Mr Jerzy Sikorski. Correspondence should be addressed to him at the Australian Orthopaedic Association, Ground Floor, William Bland Centre, 229 Macquarie Street, Sydney NSW 2000, Australia.
