Gross polyethylene failure in total knee arthroplasty.

A total of 12 total knee replacements in nine patients with evidence of gross polyethylene failure at the time of revision surgery were identified. There were nine tibial and three patellar component failures. The average time from index to revision arthroplasty was 6 years (range: 0.75 to 9.63). A retrospective cohort group was identified based on date of operation. The average patient weight of the initial group was 89.6 kg (range: 76 to 104 kg), compared with 74.8 kg (range: 47 to 108 kg) (P = .045) in the control group. There was a male sex preponderance in the failure group (P = .045). The average height of the study group was 176 cm, compared to 161 cm for the control group (P = .003). Using the modified OASDI scale, the failure group had a higher activity level (P = .023). Pre-revision limb alignment in patients with failed TKA was statistically different from controls and served as an indication of polyethylene failure (P = .04). The selection of modular prosthetic component systems that allow for easy polyethylene revision is indicated in the high risk patient group identified. Close follow up is needed to minimize the sequela of polyethylene failure.