Introduction

Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trail comparing uncemented tantalum metal tibial components with conventional cemented components of the same implant design.

Materials And Methods

90 Patients of 70 years or less with symptomatic osteoarthritis of the knee were randomized to receive either an uncemented tantalum metal tibial monoblock component or a standard cemented modular component. The same cruciate retaining total knee system was used in both groups. All patients received an uncemented femoral component and no patients had their patella resurfaced. Patient outcomes were assessed preoperatively and postoperatively using the modified Oxford Knee score, Knee Society score, and 12-Item Short-Form Health Survey questionnaire (SFS-12) score. Radiographs were analysed using the American Knee Society Radiograph Evaluation score. Operative complications, reoperations or revision surgery were recorded.

Results

The mean patient age at time of recruitment to the study was 63 years (50-70), 46 (51.1%) knees were in male patients and the mean BMI was 30.4 (21-36). At last review, all patients were between 11 and 15-years following surgery, 11 had died and 2 were lost to follow-up. Of the remaining patients 41 of the knees were cemented and 36 uncemented. There were no revisions in the cemented group and one revision in the uncemented group for fracture.

At long term follow-up the uncemented group reported better improvements in Oxford and Knee Society scores compared with the cemented group. These improvements were statistically and clinically significant (p = 0.001). The global (SF-12) scores demonstrated no statistical difference (P=0.81). Uncemented knees had better radiological analysis compared with the cemented group (p < 0.001)

Conclusion

Use of an uncemented trabecular metal tibial implant can afford better long-term clinical outcomes when compared to cemented tibial components of a matched design. However, both have excellent survivorship up to 15 years after implantation.