OBJECTIVE: To evaluate and clinically and roentgenographically compare two populations who had undergone total knee arthroplasty (TKA) with all-polyethylene (ALP) and metal-backed (MTB) tibial components. METHODS: Two groups of 40 patients underwent TKA between January 1988 and December 2004. Sixty patients showed up for evaluation, totaling 82 operated knees. From these, 22 patients had undergone TKA with only ALP (12 unilateral and 10 bilateral), 33 patients with only MTB (26 unilateral and 7 bilateral) and 5 patients had undergone both implants. The 82 operated knees were divided into two groups according to the type of tibial implant: Group 1 - 37 knees with ALP and Group 2 - 45 knees with MTB. RESULTS: There was no clinical or functional difference in outcome between the studied groups. The measurement of radioluscent line in the femoral component averaged 0.838 mm in Group 1 and 0.356 mm in Group 2 (p=0.049). For the tibial component, in the AP view radioluscent line measurement averaged 2.703 mm in Group 1 and 0.733 mm in Group 2 (p=0.000); and in the lateral view, the average values were 0.405 mm in Group 1 and 0.200 mm in Group 2 (p=0.074). CONCLUSIONS: There was no difference in the functional or clinical outcomes between the groups. However, radioluscent line was observed more frequently in the ALP arthroplasty group, in the lateral view in the femoral component as well as the AP view of the tibial component. Level of evidence IV - case series study.
Knee; Arthroplasty; Radiography
