Jordy van Sambeeck

Chapter 2 36 CR CT MRI IS 0.80 (0.72 - 0.87) 0.75 (0.66 - 0.83) 0.78 (0.69 - 0.85) BP 0.70 (0.60 - 0.80) 0.72 (0.61 - 0.81) 0.09 (0.01 - 0.21) CD 0.76 (0.67 - 0.84) 0.72 (0.61 - 0.82) 0.41 (0.22 - 0.59) MIS 0.61 (0.49 - 0.73) 0.69 (0.59 - 0.79) 0.27 (0.16 - 0.41) PTI -- -- 0.80 (0.69 - 0.88) Table 2. Inter-observer reliability: ICC (CI 95%) The ICC for inter-method reliability was calculated using measurements of the radiologist because those had the highest intra-observer reliability. However, when using the measurements of the orthopedic surgeon or resident the results were similar. The IS method showed a moderate to good ICC for comparison of all three modalities with the best agreement between radiograph and MRI. The MIS method showed a poor agreement between CR, CT and MRI (Table 3). CR/CT CR/MRI CT/MRI IS 0.77 (0.66 - 0.86) 0.86 (0.77 - 0.92) 0.70 (0.51 - 0.82) BP 0.49 (0.30 - 0.66) 0.54 (0.40 - 0.68) 0.62 (0.46 - 0.75) CD 0.63 (0.50 - 0.74) 0.64 (0.49 - 0.76) 0.61 (0.48 - 0.73) MIS 0.58 (0.44 - 0.71) 0.20 (0.07 - 0.36) 0.28 (0.15 - 0.44) Table 3. Inter-method reliability: ICC (CI 95%) OS versus RA OS versus OR RA versus OR CR IS 0.051 (± 0.164) 0.079 (± 0.208) 0.062 (± 0.144) BP 0.079 (± 0.184) 0.071 (± 0.163) 0.071 (± 0.139) CD 0.059 (± 0.182) 0.073 (± 0.185) 0.056 (± 0.146) CT IS 0.061 (± 0.162) 0.063 (± 0.165) 0.066 (± 0.168) BP 0.057 (± 0.156) 0.091 (± 0.211) 0.095 (± 0.187) CD 0.052 (± 0.195) 0.095 (± 0.191) 0.113 (± 0.206) MRI IS 0.046 (± 0.132) 0.079 (± 0.182) 0.078 (± 0.175) PTI 4.78% (± 12.90%) 8.31% (± 14.44%) 8.84% (± 14.90%) OS: Orthopedic Surgeon, RA: Radiologist, OR: Orthopedic Resident Table 4. Degree of agreement between observers according to Bland Altman analysis: Mean differences (limits of agreement)