Spinal Affections in Rheumatological Diseases

Scoliosis :

Besides rheumatoid arthritis, I had also been interested in the treatment of scoliosis which occurs due to various aetiological factors. The basic principle of treatment of scoliosis is to control the curve till the growth of the child stops at puberty. After that period the scoliotic curve also does not increase.

However, some surgeons control the curve till the age of ten and then fuse the spine. In India, since the children are not very tall we prefer to fuse the spine at a much later age say around fourteen or fifteen years of age.

There are many ways of controlling the curve, ultimately a properly done spinal fusion is the gold standard of scoliosis treatment. The technique of a properly done spinal fusion is a meticulous one involving a thorough decortication of lamina upto the transverse process, excision of face joints and placing autologous bone graft on the decorticated area.

During the early seventies (1), Paul Harrington devised a rod which could be placed over the decorticated area. The curve was distracted with an outrigger engaging two hooks placed in the laminar space at two ends of the curve. Decortication was performed and then autologous graft placed over decorticated area. This was followed by immobilization period of 6-9 months. However, the follow-up of a large number of cases, complications of Harrington rod began to appear, the commonest being breaking of the rod at the junction of the shaft of the rod and the ratchet.

The Harrington rod went into disrepute. Around the same time an era of sentimental instrumentation came into vogue. The principle of segmental instrumentation was correcting the curre at each vertebral level of the curve. This was devised by a Mexican surgeon called Luque (2). The technique required excision of spinous processes passing a double loop wire through the ligamentum flavum and the lamina and then passing it around the vertical rod of the implant. However, it was a fiddly operation. Shuffle Barger HL et al. (3) also reviewed 234 cases of idiopathic scoliosis treated by segmental instrumentation meticulous technique. There were complications like neurological damage. In such cases removal of the implant posed a major problem.

Some surgeons combined both the procedures called the Harri-Luque instrumentation procedure. This technique required the Harrington rod to be placed on the concavity of the curve which was distracted. The double loop wire was then passed in a similar manner around the lamina and was tied around the rod to secure it in place. There was some limited success for this operation. Here also it was realised that although this procedure corrected the curve and rotation of the curve to some extent the rate of complication like neurological damage was quite high.

However, in our country, scoliosis in the early stages of childhood was not treated adequately due to the mistaken motion that correction out once the child had reached the age of maturity. Hence the patients reported to us when the curved spine had become rigid and was not correctible by posterior instrumentation.

A very significant observation in relation to the curve and the rotation was made by Zeilke from Germany. He felt that approaching a scoliotic curve anteriorly would not only correct the curve but also the rotation. His anterior approach involved loosening of the curve by excision of discs in the curve. The vertebral bodies in the curve were fixed by means of screws placed in its body which were fixed by means of a rod. The whole assembly was then rotated by means of a strong lever. The space created by removal of discs was filled by bone graft taken from the excised rib. Most significant advantage of this technique was the correction of rotation.

In some cases after performing a Zielke instrumentation, posterior instrumentation and fusion was carried out either at the same sitting or after a week. In some cases where it was not possible to use Zielke instrumentation a simpler technique was used. After doing the anterior release and wound closure halo-traction was applied to the patient with the head end raised and the body weight acting as a counter traction. This device was kept on for three weeks. The patient was then taken for posterior spinal instrumentation and fusion.

Congenital Scoliosis :

This was due to imperfect segmentation or restrictive segmentation unilaterally leading to a concave bar which necessitated an immediate fusion. In some cases there was diastematomyelia. The bony spur was exicised posteriorly and then an anterior fusion was carried out. Dubousset J (4), Katti E and Seringe R, carried out epiplysiodesis of the spine in young children with congenital deformity (5). Freedman, Leong and Lub et al. performed a one stage combined procedure, both anterior and posterior excision of the hemivertebra in the lower lumbar spine. However, a periodic radiological analysis is done; if the curve is increasing excision of hemivertebra is to be carried out. If not, it should be left alone and to be kept under observation.

Paralytic Scoliosis :

These deformities have a long C- curve which should be maintained in correction with a Milwaukee brace and then fused posteriorly. In some cases a child with paralytic scoliosis had severe collapsing spine and both the lower extremities affected with polio. The case was o p e rate d wi th p o s te ri o r instrumentation and in the postoperative care a corset was given and with a lateral linge the lower limb orthosis were incorporated. It is a very satisfactory outcome since the patient who had never walked now had a posterior gait albeit with a support.

Newer techniques for correction are being devised particularly in growing children where the device has to be distracted periodically as the child grows.