High rate of tibial post-fracture in highly cross-linked polyethylene compared to conventional polyethylene in posterior-stabilized total knee arthroplasty at a minimum 12-year follow-up

Tibial polyethylene post fractures at ten-years in a bicruciate stabilised (BCS) total knee arthroplasty design

INTRODUCTION

This short paper reports a potential emerging mode of failure in three patients with a bicruciate stabilised (BCS) total knee arthroplasty.

METHODS

Three patients presented to our institution with late instability ten years after undergoing total knee arthroplasty (Journey BCS) and were asymptomatic up to this point. Retrieval analysis was performed by an external body commissioned by the NHS and all three cases were reported to the UK Medicines and Healthcare Products Regulatory Agency (MHRA).

RESULTS

Two patients were revised through simple exchange with a polyethylene tibial insert. One patient underwent a full revision of femoral and tibial components. Intra-operative findings revealed that the polyethylene post had fractured in an identical manner in all three cases. Retrieval analysis demonstrated posterior impingement and wear of the polyethylene post resulting in fatigue failure.

CONCLUSIONS

This short paper highlights a potential emerging mode of failure with Journey BCS that requires wider dissemination to raise awareness among surgeons and calls for long-term follow up of those patients who received this specific implant. Early revision with polyethylene exchange is a successful treatment in patients when femoral and tibial components are well-positioned and well-fixed.

No higher tibial post fracture rate with highly cross-linked polyethylene inserts in total knee arthroplasty at a minimum 10-year follow-up

PURPOSE

The purpose of this study was to assess tibial post fracture between highly cross-linked polyethylene (HXPE) and conventional polyethylene inserts in consecutive posterior-stabilized (PS) total knee arthroplasty (TKA) over a minimum 10-years follow-up period.

METHODS

Between July 2008 and December 2011, a consecutive series of 3264 primary TKAs was performed in 2098 patients using a PS total knee prosthesis at a single institution. The final cohort was classified into the HXPE group (792 cases) and the conventional group (2113 cases) according to insert material used during the procedure.

RESULTS

The mean follow-up period was 11.4 years in the HXPE group and 11.8 years in the conventional group. Both cases of tibial post fracture occurred in the HXPE group, a complication rate of 0.25%. These two cases required replacement with a thicker tibial insert with retention of the femoral and tibial components. There were no cases of tibial post fracture in the conventional group.

CONCLUSION

There was no difference in tibial post fracture rate between the HXPE group and the conventional group in PS TKA on long-term follow-up.

LEVEL OF EVIDENCE

IV.

Mechanical complications after total knee arthroplasty

INTRODUCTION

With the increasing demand for total knee arthroplasty (TKA) and the burden of revision TKA on the healthcare system, as well as the quality of life implications for patients, it is extremely important for surgeons to be able to anticipate and prevent TKA mechanical complications. Surgeons must be familiar with the different causes and mechanisms of TKA complications so that they can properly treat patients with failed TKAs and better avoid these complications.

AREAS COVERED

This review addresses TKA mechanical complications and provides context for the topic. A detailed review of surgical factors, implant factors, and patient factors that contribute to mechanical complications after TKA is provided. All of the literature cited in this review was gathered from the PubMed online database using different keywords based on the section of the manuscript.

EXPERT OPINION

As surgeons and engineers solve certain issues in TKA, new challenges will inevitably arise. We must continue to push forward and innovate from both a surgical technique and implant design perspective.