- its impotant to distinguish between lengthening down the anatomic axis and lengthening down the mechanical axis;
- lengthening along the anatomic axis will displace the knee medially (displacing the mechanical axis);
- lengthening along the mechanical axis does not change the "mechanical axis displacement" but does create a "zig zag" femoral shaft deformity (no functional deficit);
- some authors recommed that lengthening should be directed parallel to the femoral shaft if the hip joint and proximal femur are normal, where as, lengthening should be directed
along the mechanical axis if the femoral neck is short;
- proximal femoral lengthenings tend to move into varus and procurvatum, and therefore, some surgeons will begin distraction in 5 deg valgus;
- distal femoral lengthenings tend to move into valgus and procurvatum;
- in the report by Noonan KJ, et al (1998), there were more complications with lengthening thru the metaphysis as comparted to the diaphysis;
- average healing indices: 24 days per cm;
- knee flexion contracture:
- due to tethering effect of hamstring muscles;
- these patients should wear a knee immobilizer at night inorder to prevent knee flexion contracture;
- knee subluxation;
- more common in hypoplastic femur w/ absent ACL;
- is managed by halting fixator lengthening, and surgical lengthening of the hamstrings and IT band
Lengthening of congenital lower limb deficiencies.
One-stage lengthening for femoral shortening with associated deformity.
The effect of lengthening of the femur on the extensors of the knee. An electromyographic study.
Results of the Wagner and Ilizarov methods of limb-lengthening.
Limb Lengthening and Correction of Angulation Deformity: Immediate Correction by Using a Unilateral Fixator.
Distraction osteogenesis of the lower extremity with use of monolateral external fixation. A study of two hundred and sixty-one femora and tibiae.
Fixator-Assisted Acute Femoral Deformity Correction and Consecutive Lengthening Over an Intramedullary Nail
Sagittal Plane Deformity During Femoral Lengthening
The effect on mechanical axis deviation of femoral lengthening with an intramedullary telescopic nail
Femoral Deformity Planning: Intentional Placement of the Apex of Deformity