Effect of the foot on the mechanical alignment of the lower limbs.
The authors evaluated the effect of the foot on the loading axis of the lower limb measured from radiographs in 30 pediatric patients. Deviation at the knee was calculated for the hip-ankle (traditional) and the hip-foot lines (heel lined up with a metal wire). A trigonometric model of the limb loading axis was developed with predicted mechanical axis deviations at the knee. Statistics were based on the methods of Bland and Altman. Mechanical axis deviation at the knee in the frontal plane varies with foot height, foot-tibial angle, and genu valgum. The predicted trigonometric model was found to be in agreement with measured radiographic values. Including the foot in the radiographic measurement of limb alignment may increase validity of surgical planning for correction of malalignment and for evaluation of degenerative arthritis risk at the knee level.
Guichet
Jean-Marc
JM
Médipôle Saint-Jacques, Maxéville (Nancy); Pediatric Limb Reconstruction Service, Orthopaedic and Trauma Research Group, University of Sheffield-Children's Hospital, Sheffield, UK. j.guichet@mageos.com
Javed
Arshad
A
Russell
Jean
J
Saleh
Michael
M
D000293:Adolescent; D000367:Age Factors; D000886:Anthropometry / Q000379:methods*; D015982:Bias; D001696:Biomechanical Phenomena; D001827:Body Height; D017760:Bone Malalignment / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D002648:Child; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D035002:Lower Extremity / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D008433:Mathematics; D008954:Models, Biological; D011237:Predictive Value of Tests; D011859:Radiography; D016059:Range of Motion, Articular; D012399:Rotation; D016474:Weight-Bearing