title: An Innovative Method of Assessing the Mechanical Axis Deviation in the Lower Limb in Standing Position.
abstract: BACKGROUND
  Various methods of measuring mechanical axis deviation of lower limb have been described including radiographic and CT scanogram, intraoperative fluoroscopy with the use of an electrocautery cord. These methods determine the mechanical axis in a supine, non-weight bearing position. Although long cassette standing radiographic view is used for the purpose but is not available at most centres. A dynamic method of determining the mechanical axis in a weight bearing position was devised in this study.
  
  
  OBJECTIVE
  The aim of the study was to describe a simpler and newer method in quantifying the mechanical axis deviation in places where full length cassettes for standing X rays are not available.
  
  
  METHODS
  A pilot study was conducted on 15 patients. The deviation from the mechanical axis was measured using a manually operated, hydraulic mechanism based, elevating scissor lift table. Patient was asked to stand erect over the elevating lift table with both patellae facing forward and C-arm image intensifier was positioned horizontally. Radiological markers were tied to a radio-opaque thread and placed at the centre of head of the femur and another at the centre of the tibio-talar joint. C-arm views of the hip, ankle and knee joint were taken to confirm the correct position of the marker by varying the height of the lift table.
  
  
  RESULTS
  The mechanical axis deviation values were recorded by measuring distance between the centre of the knee and radio-opaque thread in cm. This was measured in each case both clinically and from the image on the monitor. The two values were found to be statistically same. Pain was measured on VAS. Mechanical axis deviation values and VAS score were found to be positively significantly correlated.
  
  
  CONCLUSIONS
  This technique is dynamic, unique and accurate as compared to other methods for assessing mechanical axis deviation in a weight bearing position.
authors: Professor, Department of Orthopaedics, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors: Jagannath
authors: J
authors: Kamath
authors: Senior Resident, Department of Orthopaedics, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors: Raja Shekar
authors: RS
authors: Danda
authors: Senior Resident, Department of Orthopaedics, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors: Nikil
authors: N
authors: Jayasheelan
authors: Senior Resident, Department of Orthopaedics, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors: Rohit
authors: R
authors: Singh
keywords: C-arm imaging; Deformity; Lateral compartment