Research article
Intramedullary versus extramedullary alignment of the tibial component in the Triathlon knee
1 Department of Orthopaedics, Cappagh National Orthopaedic Hospital, Finglas, Dublin 13, Ireland
2 Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin 13, Ireland
Journal of Orthopaedic Surgery and Research 2011, 6:44 doi:10.1186/1749-799X-6-44
Published: 20 August 2011Abstract
Background
Long term survivorship in total knee arthroplasty is significantly dependant on prosthesis alignment. Our aim was determine which alignment guide was more accurate in positioning of the tibial component in total knee arthroplasty. We also aimed to assess whether there was any difference in short term patient outcome.
Method
A comparison of intramedullary versus extramedullary alignment jig was performed. Radiological alignment of tibial components and patient outcomes of 103 Triathlon total knee arthroplasties were analysed.
Results
Use of the intramedullary was found to be significantly more accurate in determining coronal alignment (p = 0.02) while use of the extramedullary jig was found to give more accurate results in sagittal alignment (p = 0.04). There was no significant difference in WOMAC or SF-36 at six months.
Conclusion
Use of an intramedullary jig is preferable for positioning of the tibial component using this knee system.



