MRI Synovial Classification is Associated with Revision Indication and Polyethylene Insert Damage.
Academic Article
Overview
abstract
BACKGROUND: Patients with TKA stiffness are commonly presumed to have arthrofibrosis though no specific test exists. In patients undergoing revision TKA, we asked: (1) Do patients who are revised for stiffness display a synovial reaction on MRI that is different than patients revised for other reasons? (2) Do these patients have a different magnitude of polyethylene insert damage than patients revised for other reasons? (3) Is the MRI synovial classification associated with polyethylene insert damage? METHODS: Patients undergoing revision TKA for stiffness had a pre-operative MRI performed, and the synovium was classified on MRI in a blinded fashion as arthrofibrosis, focal scarring, polymeric reaction, infection, or abnormal. At surgery, the polyethylene inserts were removed, and graded by two reviewers for total surface damage. RESULTS: Revision indication and MRI synovial classification were associated (p<0.0001), with a greater proportion of patients assigned an MRI classification of arthrofibrosis revised for arthrofibrosis and a greater proportion of patients assigned a polymeric classification revised for aseptic loosening. Patients assigned an MRI synovial classification of polymeric had the greatest damage to the tibial insert (p<0.0001), and patients revised for the clinical indication of aseptic loosening had the greatest damage to the tibial insert (p<0.0001). CONCLUSIONS: Synovial grading on MRI is strongly associated with revision indication and polyethylene insert damage. In patients with stiffness in the absence of another complication, MRI can be a helpful diagnostic adjuvant in confirming the diagnosis of stiffness.
