title: Femoral anteversion and tibial torsion only explain 25% of variance in regression analysis of foot progression angle in children with diplegic cerebral palsy.
abstract: BACKGROUND
  The relationship between torsional bony deformities and rotational gait parameters has not been sufficiently investigated. This study was to investigate the degree of contribution of torsional bony deformities to rotational gait parameters in patients with diplegic cerebral palsy (CP).
  
  
  METHODS
  Thirty three legs from 33 consecutive ambulatory patients (average age 9.5 years, SD 6.9 years; 20 males and 13 females) with diplegic CP who underwent preoperative three dimensional gait analysis, foot radiographs, and computed tomography (CT) were included. Adjusted foot progression angle (FPA) was retrieved from gait analysis by correcting pelvic rotation from conventional FPA, which represented the rotational gait deviation of the lower extremity from the tip of the femoral head to the foot. Correlations between rotational gait parameters (FPA, adjusted FPA, average pelvic rotation, average hip rotation, and average knee rotation) and radiologic measurements (acetabular version, femoral anteversion, knee torsion, tibial torsion, and anteroposteriortalo-first metatarsal angle) were analyzed. Multiple regression analysis was performed to identify significant contributing radiographic measurements to adjusted FPA.
  
  
  RESULTS
  Adjusted FPA was significantly correlated with FPA (r=0.837, p<0.001), contralateral FPA (r=0.492, p=0.004), pelvic rotation during gait (r=-0.489, p=0.004), knee rotation during gait (r=0.376, p=0.031), and femoral anteversion (r=0.350, p=0.046). In multiple regression analysis, femoral anteversion (p=0.026) and tibial torsion (p=0.034) were found to be the significant contributing structural deformities to the adjusted FPA (R2=0.247).
  
  
  CONCLUSIONS
  Femoral anteversion and tibial torsion were found to be the significant structural deformities that could affect adjusted FPA in patients with diplegic CP. Femoral anteversion and tibial torsion could explain only 24.7% of adjusted FPA.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-Dong, Bundang-Gu, Sungnam, Kyungki 463-707, South Korea.
authors.forename: Kyoung Min
authors.initials: KM
authors.lastname: Lee
authors.forename: Chin Youb
authors.initials: CY
authors.lastname: Chung
authors.forename: Ki Hyuk
authors.initials: KH
authors.lastname: Sung
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.forename: Seung Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Park
mesh_terms: D000293:Adolescent; D002547:Cerebral Palsy / Q000150:complications* / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013977:Tibia / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D055815:Young Adult