Vincristine is occasionally used as an immunosuppressant, for example,  in treating thrombotic thrombocytopenic purpura (TTP) or chronic idiopathic thrombocytopenic purpura (ITP). Side effects
The main side effects of vincristine are chemotherapy-induced peripheral neuropathy, hyponatremia, constipation, and hair loss. Vincristine induced neuropathy is the main dose limiting side effect. Chemotherapy-induced peripheral neuropathy can be severe, and may be a reason to reduce or avoid using vincristine. The symptoms of this are progressive and enduring tingling numbness, pain and hypersensitivity to cold, beginning in the hands and feet and sometimes affecting the arms and legs. One of the first symptoms of peripheral neuropathy is foot drop: A person with a family history of foot drop and/or Charcot-Marie-Tooth disease (CMT) should avoid the taking of vincristine. A 2021 study has suggested that Anakinra can reduce the neuropathy.Accidental injection of vinca alkaloids into the spinal canal (intrathecal administration) is highly dangerous, with a mortality rate approaching 100 percent. The medical literature documents cases of ascending paralysis due to massive encephalopathy and spinal nerve demyelination, accompanied by intractable pain, almost uniformly leading to death. Several patients have survived after aggressive and immediate intervention. Rescue treatments consist of washout of the cerebrospinal fluid and administration of protective medications. Children may do better following this injury. One child, who was aggressively treated at the time of the injection, recovered almost completely with only mild neurological deficits.
(5)
Associated radiological findings include a vacuum phenomenon (in the nucleus pulposis of the adjacent intervertebral disc), reduction of disc height with corresponding loss of the disc space, marginal sclerosis of the adjacent vertebral bodies, osteophyte formation and apophyseal joint instability. With a retrolisthesis there is always a less than ideal positioning of spinal segments. There is also always a reduced anterior to posterior dimension of the spinal canal compared to the way it is supposed to be. The greater the posterior displacement, the more significant it is for producing a dysfunctional spinal cord or even a cauda equina syndrome. Joint stability
Joint stability is easily evaluated by the use of flexion and extension lateral x-ray views of the spine. A summary of part of the DRE tables (6) give a guide as to the implications of the joint instability. If either translation or angular change is determined from flexion to extension to the degree shown in the table below, then Category IV instability is present. See also Joint stability.Translation is a gliding motion where one bone of a joint glides over its neighbour. Management
References

6. Hadley, Lee A. (MD), (1973) “Anatomicoroentgenographic Studies of the Spine”. 390.7. Cocchiarella L., Andersson, G. “American Medical Association Guides to the Evaluation of Permanent Impairment”, 5th  edition, Tables 15- 3, 15-4, 15-5.8. Giles, L.G.F. ; Muller R.; and Winter G.J. (2006) “Lumbosacral disc bulge or protrusion suggested by lateral lumbosacral plain x-ray film – preliminary results.” Journal of Bone and Joint Surgery. British Volume, Vol 88-B, Issue SUPP_III, 450.