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Table 3 Multivariate analysis of risk factors for aseptic loosening after revision total knee arthroplasty

From: Influence of extension stem length and diameter on clinical and radiographic outcomes of revision total knee arthroplasty

FemurTibia
Potential risk factorCrude OR95% CIAdjusted OR95% CIpCrude OR95% CIAdjusted OR95% CIp
Age, years0.960.87–1.040.950.82–1.100.5130.940.86–1.020.940.81–1.080.421
Female sex5.351.41–20.126.751.04–43.450.045*3.420.92–12.552.670.38–18.800.323
Bone defect severity0.300.07–1.220.100.01–0.820.032*0.090.01–0.780.010.00–2.850.103
Prosthesis before revision3.111.13–8.531.210.34–4.290.7663.111.13–8.532.290.53–9.740.262
Radiographic finding
 Alignment0.730.55–0.970.990.65–1.480.9580.570.39–0.830.490.27–0.880.017*
 CFR0.850.080.01–0.670.060.01–0.680.024*0.100.01–0.840.070.01–0.800.032*
 CFR0.7 > 2 cm0.070.01–0.330.020.01–0.330.006*0.210.05–0.770.330.06–1.720.188
 CFR0.7 > 4 cm0.110.01–0.910.040.01–0.660.025*0.140.02–0.710.230.03–1.480.123
 CFRmax0.940.89–0.980.930.87–1.000.0510.960.91–1.010.550.32–0.900.407
 CFR0.85 length0.370.13–0.970.360.12–1.000.050*0.400.15–1.070.380.13–1.090.073
 CFR0.7 length0.500.31–0.790.430.23–0.790.0070.700.52–0.940.760.55–1.030.081
  1. Bone defect severity was assessed using the Anderson Orthopaedic Research Institute classification. Alignment indicates the femoral-tibial angle. CFR was calculated as the ratio between the stem width and the medullary canal width. CFRx stands for CFR > x. CFRx > y indicates stem length > y for CFR larger than x. CFRx length indicates the stem length for which CFR > x. CFRmax indicates the maximum CFR over the entire length of the stem. CI, confidence interval; CFR, canal filling ratio; OR, odds ratio; *: p < 0.05