Posterior Spinal Tuberculosis: A Review

Abstract

Natural history of posterior spinal tuberculosis has been described. Classifications of the posterior spinal tuberculosis disease process and principles of management based upon the clinical behavior of the disease has been highlighted and emphasized. A thorough review of literature was conducted with the aim to provide the clinicoradiological correlation of the natural history of posterior spinal tuberculosis in described. Management strategy is developed based upon the severity of the clinical behavior of the disease. In anterior spinal tuberculosis, motor fibers are compressed first as they are placed anterior to the sensory tracts in the spinal cord. The sensory fibers are therefore involved in late stages. Ironically, in posterior spinal tuberculosis when compression is predominantly from the posterior aspect of the cord, we again find that motor fibers are involved prior to the sensory fibers. This is in contradiction to the general belief. It is difficult to offer any simple explanation to this apparent paradox. In general, motor fibers are considered more susceptible to pressure effect, whereas sensory fibers are more susceptible to ischemia. That is why in compression paraplegia, signs and symptoms of motor loss appear prior to the sensory loss, as collaterals prevent ischemia for quite some times. In posterior spinal tuberculosis when compression is from the posterior aspect of the cord, at first pressure is exerted on the column of cerebrospinal fluid (CSF) surrounding the cord and gets transmitted to the ligamentum denticulatum. Motor fibers in the close vicinity, get pulled and show early involvement. Secondly, in compression from the posterior aspect of the cord, the cord is displaced anteriorly and anteriorly placed motor fibers are compressed against the anterior wall of the bony spinal canal causing early motor fiber functional loss. Therefore similar classification of paraplegia predominantly based upon the progressive motor weakness is valid for paraplegia noted following posterior spinal tuberculosis. Neurological deficit grading based management is developed. Grade 1 and 2, conservative treatment, grade 3, gray zone and grade 4, operative treatment is emphasized. The five stages of natural history of tuberculosis of spine have been developed from the clinician’s point of view. However, indications of surgery are different than what are described for the anterior spinal tuberculosis. Principles of management with role of rest, braces, chemotherapy and surgery are discussed. Management of posterior spinal tuberculosis of spine, in general, it is no different than management of soft tissue tuberculosis, in HIV negative or positive patients. Role of surgery is very different than anterior spinal tubercolosis. Management of posterior spinal tubercular paraplegia, is simple, logical, efficient and easy to understand and remember by any orthopedic/treating surgeon.