- Spinal Fracture:
- this type of fixation is now outdated, and the text is maintained for historical context;
- capable for providing adequate fixation for most spine fractures;
- will reduce angular deformities and restore vertebral body height;
- indications:
- anterior and anterior/middle column injuries can be treated by the use of contoured distraction rods;
- presence of an intact posterior column allows secure fixation;
- contraindications:
- disrupted posterior & middle middle column;
- flexion bending resulted in dislodgement of upper hook from lamina at only 30 N meters;
- when a compression system was applied to such an injury, failure occurrs at more than 80 N meters;
- avoid overdistraction:
- posterior column must be reconstructed prior to the application of distractive forces in the triple column injuries to prevent overdistraction;
- technical points:
- contour rods & restore normal saggital plane anlignment;
- because rods are flexible, they may not be able to control saggital plane alignment in larger individuals;
- hooks that are placed from two intact lamina above and two intact lamina below the level of injury will fail at 60 N meters;
- at 3 lamina above lesion to two vertebra below, lesion failed at > 80 N meters;
- Sciolosis:
- this type of fixation is now outdated, and the text is maintained for historical context;
- has been the historical gold standard for treatment of thoracic curves;
- in recent years, more rigid and segmental forms of instrumentation have been developed both for posterior and for anterior fixation;
- effective in correcting scoliotic curves in coronal plane;
- level of arthrodesis:
- arthrodesis of only thoracic curve is necessary (King type II), in which compensatory lumbar curve is smaller and more flexible on bending;
- bottom of arthrodesis should extend to the most cephalad vertebra which is crossed by a line drawn thru the middle of
S-1 perpendicular to the iliac crestline);
- lower level of arthrodesis in lumbar curves should not extend to lower lumbar region unless it is absolutely necessary;
- avoid arthrodesis to L-5 & L-4, if possible;
- w/ lower level of arthrodesis, there is more back pain;
- disadvantages:
- thoracic hypokyphosis, deviations in axial rotation, & lordosis are inconsistently corrected;
- reduced lumbar lordosis ("flat-back" deformity) can develop over time;
- loss of fixation:
- either partial or total loss of correction;
- 10-25% loss of correction from Harrington instrumentation, but risk is lower in pts who are immobilized by a cast or brace;
- immobilization is therefore often recommended after surgery;
- post op:
- immobilization in cast or brace for 4 to 9 months has been gold standard;
Adolescent idiopathic scoliosis treated by Harrington-rod distraction and fusion.
Adult idiopathic scoliosis treated with Luque or Harrington rods and sublaminar wiring.
Complications following Harrington instrumentation for fractures of the thoracolumbar spine.
Harrington instrumentation and arthrodesis for idiopathic scoliosis. A twenty-one-year follow-up.
Low lumbar burst fractures. Comparison among body cast, Harrington rod, Luque rod, and Steffee plate.
Late neurological complications of Harrington-rod instrumentation.