Selective Dorsal Rhizotomy does not alleviate contractures caused by spasticity from before the surgery takes place; it simply prevents any more contractures or spasticity from occurring in future. With or without rhizotomy, the only way contractures can ever be relieved is via orthopaedic surgery . Fixed orthopaedic deformities of the legs caused by the previous years of intense spasticity are also not relieved by the nerve surgery and must also be corrected surgically. Whether or not to undergo such post-rhizotomy orthopaedic surgery depends on the circumstances of the rhizotomy recipient in question.
Spinal infusion involves placing a tiny catheter into the spinal sac or epidural space. These spaces around the spinal sac are separated only by a thin membrane called the dura mater which includes a layer called the arachnoid membrane. Spinal or subarachnoid infusions place medicine inside the spinal sac (inside the dura mater) where the medicine can spread out in the cerebral spinal fluid (CSF) and affect wide areas of pain. Epidural ( above the dura ) medicines flow into the epidural space where the fluid spread is much more restricted by the epidural contents (epidural fat and blood vessels). Where the catheter is placed, and the kind of medicine infused depends on the patient, the type of pain, the duration of infusion, and many other factors.