Measurement of reference value of maximum epiphyseal width lateral to Klein's line and modification of Klein's line in 2 800 hips of 1 400 normal children / 国际儿科学杂志

ABSTRACT

Objective To investigate the maximum epiphyseal width lateral to Klein' s line (MEWLKL) and modification of Klein's Line (namely difference value of bilateral MEWLKL) on hip plain radiographs of normal children, and to investigate the relationship between MEWLKL and modification of Klein's Line and gender and body side, respectively.Methods Anteroposterior (AP) view pelvic plain radiographs of fourteen thousand eight hundred and thirty-seven cases aged from zero to fourteen years old in Shengjing Hospital of China Medical University from 2005 January to 2014 December were reviewed.Seven thousand one hundred and forty-seven normal AP pelvic plain radiographs were included in the present study.Fourteen groups based on the age from one years old to fourteen years old were divided.One hundred cases in each age group, including fifty males and fifty females, were randomly selected.Fourteen hundred AP view pelvic plain radiographs including twenty eight hundred hips were measured.The reference value of MEWLKL and modification of Klein's line were measured using AutoCAD2007 software.the Normal distribution test were performed using Excel and SPSS19.0 software.The relationship curve between MEWLKL and modification of Klein's Line and age were drawed.The intra-group difference between MEWLKL and gender and body side were performed using t-test in normal children.The inter-group difference between modification of Klein's line and average MEWLKL were performed using one-way analysis of variance in normal children.Results The reference value of MEWLKL and modification of Klein's Line were both normal distribution.Average reference value of MEWLKL were (5.20 ± 1.92) mm, (5.04 ± 1.88) mm in male, and (5.36 ± 1.94) mm in female (P =0.000), (5.06 ± 1.87) mm on the left side, and (5.33 ± 1.96) mm on the right side (P =0.000).The curve of reference value of MEWLKL in fourteen general groups were similar to those of fourteen male groups and fourteen female groups, and reference value of MEWLKL increased with age.It was in the trough at the age of five [general groups: (3.77 ± 1.00) mm;male groups: (3.53 ± 1.00) mm;female groups: (4.01 ±0.94) mm], and it was at the peak at the age of thirteen [general groups: (7.49 ± 1.43)mm;female group: (7.84 ± 1.42) mm].It was at the peak at the age of fourteen in male groups, and the value was (7.24 ± 1.46) mm.The reference value of MEWLKL in fourteen groups and in female groups both fell slightly after the age of fourteen.There were second trough, (6.44 ± 1.86) mm to (6.38 ± 1.15) mm,at age eleven to twelve in female groups.The curves of reference value of MEWLKL on bilateral sides was very similar, and they increased with age.They were in the trough at the age of five [(3.54 ± 0.84) mm in left side and (4.00 ± 1.10) mm in right side], and they were at the peak at the age of thirteen [(7.25 ± 1.57)mm in left side and (7.72 ± 1.24) mm in right side].The curves both fell slightly after the age of fourteen.The general reference value of modification of Klein's line was (0.93 ±0.82) mm.The average value of each age group waved in the level of 1.0 mm.Statistical significance were found in comparison of two intergroups, age eight versus age seven (P =0.011), and age eleven versus age ten (P =0.04).The maximum value of modification of Klein's line in four of fourteen groups were greater than 2.0 mm, including 2.02 mm in age ten, 2.05 mm in age eleven, 2.3 mm in age thirteen, and 2.17 mm in age fourteen, respectively.Conclusion The value of modification of Klein's line in normal children can be more than 2.0 mm, and the average value waved in the level of 1.0 mm.It is not reliable to determine slipped capital femoral epiphysis using modification of Klein's line.