Isolated Zone 2 and Zone 3 Cementless Tibial Fixation Shows Early Promise in Revision Total Knee Arthroplasty.

BACKGROUND

Fixation in revision total knee arthroplasty(rTKA) should occur in at least 2 zones(epiphysis, metaphysis, or diaphysis) to maximize fixation strength. We report here the short-term survivorship of unsupported tibial base plates in rTKA when used with a cementless metaphyseal sleeve and non-cemented stem.

METHODS

We retrospectively reviewed all patients undergoing rTKA between 2014 and 2021 by a single surgeon at a single institute. We identified 17 patients with a minimum follow-up of 1 year.

RESULTS

The average age at surgery was 66.4 years (range 50-80) and the average BMI was 34.6 (range 22.4-43.3). One patient had Type 1 and 16 patients had Type 2 bone loss preoperatively (Anderson Orthopaedic Research Institute classification). Two patients (11.8%) received a standard posterior stabilized insert, nine patients (52.9%) received a varus valgus constrained insert and the remaining 6 (35.3%) patients received a hinged implant. There were no cases of revision for loosening, fracture or mechanical failure of the tibial component construct at an average follow up of 2.9 years (maximum 7.9 years). One patient required revision for end of stem pain. Only 1 patient developed subsidence (≤ 3 mm) but did not have any clinical mechanical symptoms suggestive of loosening.

CONCLUSION

We report a 100% survivorship free of revision for loosening or mechanical failure of the tibial construct at short term follow up when using an unsupported tibial base plate with a metaphyseal sleeve and non-cemented stem. Based on early data, metaphyseal sleeves with a stable stem fixation in the tibia can be used without additional tibial tray fixation with cement.