Patellar instability: the reliability of magnetic resonance imaging measurement parameters

Table 3 Inter-observer reliability of the MRI measurements for patellar instability

Measurement	ICC	95%CI	Mean difference	95%LoA	SEM	MDC₉₅
Patellar position
Angle of Fulkerson, deg	0.975	0.961~0.983	0.275	−1.717~2.266	0.732	2.029
Angle of Grelsamer, deg	0.870	0.814~0.910	−0.157	−4.695~4.381	1.632	4.523
Angle of Laurin, deg	0.931	0.897~0.954	0.480	−3.081~4.042	1.320	3.658
PTA, deg	0.952	0.930~0.968	−0.039	−2.411~2.332	0.854	2.367
LPD, mm	0.979	0.969~0.986	−0.087	−0.916~0.741	0.303	0.840
BSO, %	0.923	0.887~0.948	−0.004	−0.040~0.033	0.013	0.037
CA, deg	0.906	0.864~0.935	−0.392	−11.146~10.362	3.774	10.460
Trochlear dysplasia
SA, deg	0.963	0.946~0.975	−0.137	−3.919~3.645	1.366	3.786
LTI, deg	0.963	0.939~0.977	−0.392	−2.549~1.765	0.819	2.272
TFA, %	0.822	0.748~0.876	−0.008	−0.146~0.130	0.050	0.138
TGD, mm	0.931	0.900~0.953	0.011	−0.972~0.994	0.353	0.979
Patellar height
ISI	0.821	0.725~0.886	−0.006	−0.152~0.141	0.052	0.145
MISI	0.879	0.810~0.923	0.005	−0.189~0.199	0.069	0.191
CDI	0.909	0.957~0.943	−0.001	−0.114~0.112	0.040	0.112
BPI	0.885	0.820~0.927	0.010	−0.145~0.165	0.056	0.154
PTI	0.956	0.930~0.973	0.008	−0.088~0.103	0.034	0.095

ICC Intraclass correlation coefficient, LoA Limits of agreement, CI Confidence interval. SEM: standard error of measure, MDC₉₅ Minimal detectable change at 95% confidence level, deg degree

ISSN: 1471-2474