- See:
Cotrel-Dubousset
- Discussion:
- multisegmental hook systems, like
CD and TSRH, provide multiple points
of fixation to the spine and allow both compression and distraction
on the same rod;
- added strength is obtained w/ use of several transverse traction devices,
which convert the system to rigid rectangle;
-
addvantages:
- postop bracing is minimized w/o jeopardizing reduction & fusion;
- allows use of shorter instrumentation & immobilizing of fewer segments;
- hooks can be used in both distraction & compression modes, allowing
complex curve correction and providing stability w/ segmental fixation;
- improved correction of thoracic hypokyphosis (upto 10 deg);
- preservation of lumbar lordosis;
- derotation of the spine;
- postoperative immobilization is not required;
-
disadvantages:
- require more time to insert than do the other posterior systems;
- moderate amount of manipulation is required to connect multiple
hooks to rods while reducing unstable spine injury;
- Technical Points:
- length of lever arms be equal above & below frx;
- double lamina claws be applied at both cephalic &caudal ends of fixation;
- hook placement;
- hooks are placed into areas where there is no canal compromise;
- in cases of frx w/ severe retropulsion, do not place sublaminar hooks at
T12 for an L1
Burst fracture, since canal is narrowest at this site;
- instead proximal claw is placed one level cephalad to routine levels;
