1 Preliminary remark topenlarge
The halo ring can be used for traction and closed reduction of fractures.
Closed reductions should only be performed in conscious patients or in OR prior to surgery.
The halo ring can be placed under local anesthesia in conscious patients. The patient is in a supine position on a stable surface.
The halo ring can be connected to a halo vest to provide stability following closed reduction.
The halo vest has to be sized prior to the procedure.
2 Halo ring installation topenlarge
The circumference of the patients head is measured and an appropriately sized halo ring is selected.
The ring should allow 1-2 cm clearance from the skull.
Temporary halo fixation
The appropriate halo ring is placed with temporary stabilization pins.
Anterior screws are inserted 1 cm superior to the lateral 1/3 of the eyebrows.
The eyelids should be kept closed.
The posterior screws are placed approximately 5 cm posterior to the ear.
Ideally any posterior screw should be directed towards its contralateral anterior screw, and vice versa.
Care should be taken to prevent contact between the halo ring and the ears.
For adults at least four screws are necessary. For children, 6-8 screws are recommended. The halo ring should be placed inferior to the equator of the skull.
The pin sites are cleaned with a disinfectant and the skin and periosteum is infiltrated with local anaesthesia.
During insertion of the screws, the eyelids of the patient should be kept closed. If screws are inserted into the supraorbital rim with the eyelids open, the patient may not be able to close the eyelids postoperatively.
Initially the permanent screws are tightened by hand, followed by the use of a torque screw driver. Opposing screws are tightened sequentially 1, 2, 3, and 4.
For adults the maximum torque should be set to 0.56 kg/cm3 and 0.28 kg/cm3 for children.
3 Reduction top
Closed reduction is performed under image intensifier. Extension or flexion is applied depending on the position of the fragments. This is followed by compression. Reduction should not include traction maneuvers.
4 Attachment to halo jacket topenlarge
After reduction is achieved and confirmed on X-rays, the halo ring is attached to a halo jacket. Maximum stability is achieved when rods are symmetrical and parallel.
Postoperative X-ray control
X-rays are performed and the position of the spine is checked.
Screw site care
As the screws loosen over time, they should be re-torqued after 24h, 3 days, and then weekly until the halo is removed.
Screw sites should be cleaned daily and the screws replaced in case of loosening or signs of infection.