Tibial torsion in cerebral palsy: validity and reliability of measurement.
Physical examinations of tibial torsion are used for preoperative planning and to assess outcomes of tibial osteomy in patients with cerebral palsy (CP). The thigh-foot angle (TFA) and transmalleolar axis (TMA) are commonly used, and the second toe test recently was introduced. However, the validity and reliability of the three methods have not been clarified. This study was performed to evaluate the validity and reliability of these physical measures. We recruited 18 patients (36 limbs) with CP. During reliability sessions, three raters with various levels of orthopaedic experience independently measured tibial torsion using the three different methods during one day before surgery. Validity was assessed by performing a correlation study between physical examination and two-dimensional computed tomographic (CT) findings. Interobserver reliability was greatest for the TMA followed by TFA and then by the second toe test with intraclass correlation coefficients of 0.92, 0.74, and 0.57, respectively. In terms of the concurrent validity, the correlation coefficients (r) for the CT measurements were 0.62, 0.52, and 0.55. When depicting tibial torsion by physical examination, all three methods had substantial validity, but test reliability and validity were highest for TMA measurements.


METHODS
Level I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
Lee
Sang Hyeong
SH
Department of Orthopedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-Dong, Bundang-Gu, Sungnam, Kyungki, 463-707, Korea.
Chung
Chin Youb
CY
Park
Moon Seok
MS
Choi
In Ho
IH
Cho
Tae-Joon
TJ
D000293:Adolescent; D001847:Bone Diseases / Q000175:diagnosis* / Q000209:etiology; D002547:Cerebral Palsy / Q000150:complications*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D013977:Tibia; D014102:Torsion Abnormality / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult