Summary

This study found no difference between cemented and uncemented Total Knee Arthroplasty designs at 2 years, with reference to survivorship, patient outcomes and radiological parameters.

Abstract

Introduction

The main cause of aseptic total knee arthroplasty (TKA) revision is implant loosening, which is linked to poor cement mantle quality. Cementless components aim to provide improved fixation through biological osseointegration; however, early TKA designs had an increased rate of revision due to a lack of initial press-fit and bony ingrowth, particularly uncemented tibial and patella components.
Highly porous metal designs may alleviate this issue, but randomised clinical data on fully uncemented TKA (tibial, femoral, patella) is lacking. The aim of this study is to investigate outcomes of fully uncemented compared with cemented fixation in TKA.

Methods

Three-hundred and nineteen patients under 75 years of age were enrolled in this two-arm, single-blinded, non-inferiority randomised controlled trial. Follow-up was at 6 weeks, 6 months, 12 months, 24 months, and is planned for 5 years and 10 years. The primary outcome was implant fixation, assessed by presence of postoperative progressive radiolucencies using the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Secondary outcome measures include Oxford Knee Score (OKS), International Knee Society System (IKSS), and the Forgotten Joint Score-12 (FJS-12).

Results

At two years, 300 patients (151 cemented vs 149 uncemented) were available for follow up. No difference was seen on radiographic analysis at 2 years, 1 lucent line was seen in the cemented group and 0 in the uncemented group (0.7% vs 0%, p = 0.7). There were no statistical differences in patient reported outcomes at 2 years: Oxford knee score 42.5 vs 41.8 (p=0.35), International Knee Society 84.6 vs 84.0 (p=0.76), Forgotten Joint Score 66.7 vs 66.4 (p=0.91). There was one revision for deep infection in each group (0.3%). Twelve cemented and 6 uncemented knees underwent manipulation under anaesthetic (8.3% vs 5.3%, 95% CI -2.81% to 8.9%, p = 0.3). Operative time was 73.7minutes in the cemented versus v 70.7minutes in the uncemented group.

Discussion And Conclusion

Early results of this study found no difference between cemented and uncemented TKA designs at 2 years, with reference to survivorship, patient outcomes and radiological parameters.