Medium to Long term radiographical analysis of porous-coated metaphyseal sleeves in revision knee arthroplasty show stable fixation and excellent survivorship.

Description

Introduction

The rate of revision total knee arthroplasty (rTKA) is predicted to increase by more than 600% between 2005 and 2030. This is due to a a steady rise in the number of primary procedures combined with increasing life expectancy of the population. The survivorship of primary TKA has been extensively investigated, there has not yet been an agreed method for rTKA, validated with long term results. One of the most challenging aspects of rTKA is managing bone loss, for which a number of techniques have been investigated; including augmentation with cement, bone graft and modular augmentation with blocks or wedges. Using the zonal classification of fixation for rTKA use ofmetaphyseal sleeves in zones 2 and three has become a popular option with some promising immediate and short term results . This study aims to investigate the medium to long term radiographic stability and survivorship of metaphyseal sleeves in rTKA.



Methods

Prospectively collected data on the first 100 patients in our institution to receive a metaphyseal sleeve rTKA was analysed. Tibial and femoral bone loss was classified according to the Anderson Orthopaedic Research Institute (AORI) bone defect classification intra-operatively. Post-operative complications of infection, re-revision and dislocation were assessed. The immediate post-operative radiograph was used as a baseline, and subsequent latest follow up radiograph used for analysis of osteolysis and implant subsidence. The radiographs were taken routinely at 1,3,5 and 10 years. The radiographs were reviewed by an attending and resident orthopaedic surgeon as well as a radiologist to reduce intra-observer bias.



Results

100 patients were reviewed, average age at time of revision was 71.5 years (44.4-89.5). The AORI defect classifications in femur were 47% type 1, 36% type 2 and 17% type 3. Tibia defect classification was 37% type 1, 52% type 2 and 11% type 3. Average length of follow-up was 61.2 months (11.2-120.3). At final follow-up 3 patients (3%) had radiological subsidence of the prosthesis. 6 patients (6%) had radiological signs of lucency/osteolysis surrounding the implant. 3 patients had deep infection requiring washout. 1 patient required re-revision surgery (survivorship 99%).





Discussion / Conclusion

Porous-coated metaphyseal sleeves provide excellent implant stability and survivorship up to 10 years. There is minimal subsidence, osteolysis and rates of revision. To our best knowledge the current study represents the largest cohort with longest follow-up period which has been investigated in this technique. Our results are consistent with other studies using shorter follow-up periods, and demonstrate that minimal subsidence and low revision rates are maintained over the first 10 years. There is limited literature to compare medium to long term outcomes to other techniques of rTKA. The current study supports the use of a metaphyseal sleeve system is an effective technique for rTKA.

Period	25 Mar 2022
Event title	American Academy of Orthopaedic Surgeons: Annual meeting 2022
Event type	Conference
Location	Chicago, United States, IllinoisShow on map
Degree of Recognition	International