Patellar instability: the reliability of magnetic resonance imaging measurement parameters

Table 2 Intra-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	0.969	0.953~0.979	0.216	−2.019~2.450	0.808	2.240
Angle of Grelsamer, deg	0.938	0.910~0.958	0.000	− 3.096~3.096	1.111	3.080
Angle of Laurin, deg	0.945	0.919~0.962	−0.039	−3.325~3.247	1.175	3.257
PTA, deg	0.953	0.931~0.968	0.069	−2.276~2.413	0.841	2.330
LPD, mm	0.980	0.970~0.987	−0.085	− 0.899~0.728	0.298	0.825
BSO, %	0.898	0.852~0.930	−0.005	− 0.047~0.038	0.015	0.043
CA, deg	0.908	0.866~0.937	−0.892	−11.037~9.253	3.685	10.215
Trochlear dysplasia
SA, deg	0.964	0.947~0.975	0.098	−3.798~3.994	1.390	3.852
LTI, deg	0.940	0.912~0.960	−0.324	−3.152~2.505	1.040	2.883
TFA, %	0.881	0.830~0.918	0.008	−0.103~0.119	0.040	0.112
TGD, mm	0.940	0.913~0.959	−0.012	−0.937~0.912	0.331	0.919
Patellar height
ISI	0.876	0.807~0.922	−0.009	− 0.128~0.111	0.043	0.119
MISI	0.911	0.859~0.944	−0.018	−0.187~0.152	0.062	0.171
CDI	0.917	0.869~0.948	−0.007	− 0.107~0.092	0.036	0.100
BPI	0.851	0.769~0.905	0.005	− 0.166~0.177	0.061	0.169
PTI	0.960	0.936~0.975	−0.005	−0.088~0.103	0.034	0.093

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