BACKGROUND

Instability is a common cause for revision total knee arthroplasty (TKA). The risks and benefits of polyethylene liner exchange (LE) as compared to full metal component revision continue to be debated. The purpose of this study was to investigate the success rate and complication profiles of revision TKA for instability based on surgical procedure.

METHODS

This was a retrospective study of patients undergoing revision TKA for instability from 2015 to 2019. Patients with prior revisions were excluded. 42 patients undergoing isolated polyethylene LE without an increase in constraint were compared with 48 patients undergoing full component revision revision (FCR) of both tibial and femoral components. The primary outcome was differences in rerevision for instability. Noninstability reoperations, 90-day readmissions, and lengths-of-stay were also compared.

RESULTS

LEs had a 10.1% higher rerevision for instability rate that approached statistical significance (LE 14.3% versus FCR 4.2%, P = .092). Additionally, FCR had a 4.2% rate of aseptic loosening and a 4.2% rate of periprosthetic-joint-infection, whereas LE had none (P = .181). FCR also had a longer length-of-stay (FCR 3.0 ± 1.3 versus LE: 1.8 ± 0.9 days, P < .001). No differences were found in 90-day readmissions (LE 7.1% versus FCR 4.2%, P = .661).

CONCLUSION

All component revision may have a higher success rate than isolated LE in addressing instability but is associated with higher rates of surgical complications. With appropriate patient selection and risk-benefit discussion, isolated LE may be a reasonable surgical option for TKA instability with a lower complication profile and length-of-stay.