Abstract
Purpose
The outcome following isolated liner exchange for revision knee arthroplasty, while an attractive option for its simplicity, has a mixed outcome reported in the literature. We report our experience in patients who had a minimum of two years follow-up.
Method
From our database we identified 44 cases in 41 patients who had an isolated liner exchange for a failed primary knee replacement. Twenty were female and the mean body mass index was 33 (range 20 to 49). The mean time to revision from their index procedure was 76 months (range 8 to 152). The mean age at revision was 69 years (range 45 to 90). Patients were assessed by use of validated quality of life questionnaires: Oxford-12, UCLA Activity Level, WOMAC and SF-12. Patients current scores were compared to pre-operative scores in 19 cases. Radiographs were assessed for polyethylene wear, osteolysis and alignment with respect to the mechanical axis. Intra-operative findings were compared to radiographic findings.
Results
The main clinical indication for liner exchange was polyethylene wear 73% (32/44), stiffness 11% (5/44), instability 7% (3/44), pain 7% (3/44) and failed locking mechanism 2% (1/44). Five patients had died, four patients refused to participate. Four (9%) knees were subsequently revised: two for aseptic loosening of the femoral component and two for the tibial component, between one and 12 years after liner exchange. Twenty-nine patients completed quality of life questionnaires. The mean follow-up was 58 months (range 24 to 123). Significant improvement was seen in the Oxford-12, the SF-12 physical component and all WOMAC domains.
Conclusion
Our revision rates are low compared to published results. When patients are selected appropriately, an isolated liner exchange can be a useful operation for the treatment of a failed primary total knee replacement.
