Management of severe Kyphoscoliosis with Pre-Operative
Halo Pelvic Distraction followed by  Posterior Instrumented Fusion

History and examination:

A 27-year-old lady presented with a progressive spinal deformity and exertional dyspnoea. The spinal deformity was present since childhood and the exertional dyspnoea was present since one year. On examination she had a severe rigid left-sided thoracic kyphoscoliotic curve with a coronal decompensation. There were no neurocutaneous markers to suggest the presence of neurofibromatosis or a congenital spinal cord anomaly. She had normal neurology in all four limbs. An important finding was breath count of 13 and a Spo2 of 88 % in room air.A plain radiograph and CT scan showed a severe deformity measuring more than 90 degrees. The MRI did not reveal any intraspinal or cord anomaly.
 

Figure 1 and 2: Clinical photographs of the patient. Note that the upper level of the curve is nearly at the level of the occiput with the result that the neck has funneled into the chest.Figure 3 and 4:  3-D CT scan of the spine showing the severity of the curve. A plain radiograph of the curve would not be able to reveal the true dimensions due to the overlap in both views.
Treatment considerations:

Here we had a 27-year-old lady with progressive dyspnoea, progressive spinal deformity and a significant cosmetic disfigurement. The treatment options were limited. In view of the rigidity of the curve, a single stage posterior instrumentation and fusion may have arrested the progression of the curve but the respiratory embarrassment would have persisted. An anterior approach to release the tight anterior structures in the concavity of the kyphoscoliotic segment would have been fraught with danger.

 
Figure 5:  Position of the pins of the halo in the skull.Figure 6:  Position of the Denham pins passing through the iliac crests.Figure 7: An assembled halo-pelvic apparatus.Figure 8: The patient after application of the halo-pelvic apparatus. Note that the funneling of the neck has been reversed.

In view of the limitations mentioned, we decided to apply a halo-pelvic distraction apparatus, obtain the maximum possible correction within safe limits and then perform a posterior instrumented fusion. We applied a halo with four pins and a pelvic hoop with two Denham pins traversing the iliac crest. The halo and the pelvic hoop were connected with four vertical expandable threaded rods. With gradual distraction we obtained a 10-centimetre increase in height and more importantly the respiratory compromise improved with the breath count increasing to 30.
 

Figure 9 and 10: Radiographs after the posterior instrumented fusion. Note the extent of improvement compared to the pre-operative CT scan.

Figure 11 and 12: Clinical photographs after removal of the halo. Note the improvement in curve magnitude. The funneling of the neck has been reversed and the cosmetic appearance has improved considerably.

The patient was reviewed at regular intervals and a careful examination of the neurological status and the cranial nerves was carried out at each visit. When a height gain of 10 centimetres was achieved, the patient developed mild paresthesia in the medial border of the left forearm and hand. At this point, the frame was shortened and the paresthesias disappeared. The final gain in height was 8 centimetres. A posterior instrumentation and fusion was performed with the halo-pelvic apparatus in situ. The apparatus was retained for a period of six months after surgery and then removed. At the end of the treatment the patient was relieved of the dyspnoea and the curve had improved cosmetically. The radiographs showed satisfactory fusion of the curve.Using the halo-pelvic distracter we were able to improve the respiratory function and achieve partial correction of the deformity before a definitive instrumented fusion.

A few transient complications were encountered. Mild pin tract infection developed in the pelvic pins which subsided with antibiotics. Transient paraesthesias in the left upper limb developed at the maximum limit of distraction. The paraesthesia disappeared when the frame was shortened. There was no evidence of cranial nerve palsy.

In conclusion, preoperative halo-pelvic distraction followed by instrumented fusion is an option in patients presenting with severe spinal deformities and respiratory compromise.

Review of literature:

Most of the references in literature pertaining to preoperative halo-pelvic traction date back to the 1970’s.  This is because of the low incidence of severe neglected spinal deformities in the developed countries. Winter et al  (JBJS (A) 1968) noted that  halo distraction provides a method to correct and stabilise curves involving the cervical and upper thoracic spine especially when respiratory function was impaired and external pressure on the thoracic cage must be avoided. Moe (OCNA 1972) stated that in severe or rigid curves, prior correction by cast or traction makes posterior spinal fusion technically easier and safer. Kalamchi and Hodgson (JBJS (A) 1976) advised that a halo-pelvic apparatus should be reserved for a spinal deformity in which other means of correction will not yield satisfactory results.

This modality of treatment is not without complications. The complications described in literature are pin tract infections, cranial nerve neuropraxia  [Nerves 6, 10, 12], Spinal cord and brachial plexus injury, cervical spondylosis and psychological imbalance. Avascular necrosis of the odontoid and superior mesenteric artery syndrome have also been described.