Cemented Versus Cementless Unicompartmental Knee Arthroplasty (UKA) - A Single-blind Randomised Controlled Trial
Cemented Versus Cementless Unicompartmental Knee Arthroplasty (UKA) - A Single-blind Randomised Controlled Trial
Unicompartmental knee replacement for selected cases of osteoarthritis is less invasive than total knee replacement. It gives better range of movement; patients stay for shorter time in the hospital and have a more natural feel than total knee replacement. Usually, the implant is fixed in the bone using bone cement. However, there are potential disadvantages of using bone cement. The operation takes longer; cement can get squeezed out into the surrounding tissues and may interfere with function. To avoid these problems, the implant can be fixed without cement. Cementless components have a special coating to encourage bone in-growth and fixation. Although the investigators believe cementless fixation will be at least as good as cemented fixation, there is a risk that it could be worse and might result in loosening.
The aim of this study is therefore to compare the outcome of cemented and cementless unicompartmental knee replacement.
Design: A prospective, randomised trial to compare the outcome of cemented and cementless unicompartmental knee replacement.
Size: 40 subjects in total will be recruited with 20 in each arm.
Methods: Patients will be recruited from the routine waiting list for unicompartmental knee replacement at the Nuffield Orthopaedic Centre. All subjects will have the procedure explained and be fully consented prior to the procedure.
Randomisation: Patients will be randomly allocated to receive either a cemented or cementless Oxford Unicompartmental Knee Replacement. This will be performed using a randomisation program based on optimisation (Minim). Subjects will be stratified according to sex and age.
Operation: All subjects will undergo the same surgical approach. 0.8mm Tantalum marker balls will be placed at standardised sites on the femur and tibia in all cases. All cemented components will be secured using the same cement. Cementless components have a hydroxy-appatite coating to facilitate bone ingrowth.
Follow-up: All patients will be followed up at 0, 3, 6, 12, 24, 60, and 120 months with clinical and radiological assessment. Clinical assessment will involve documentation with the Oxford Knee Score. Patients will undergo radiostereometric analysis and fluoroscopy to study implant migration and occurence of radiolucency, respectively.
Inclusion Criteria:
Exclusion Criteria: