Study of Causal Factors of Pott's Paraplegia

Recent advances in medicine, preventive-medicine, and orthopedic surgery have reduced the incidence of Pott's paraplegia which has been one of the serious complications of tuberculosis of spine, but it remains as a problem in the field of orthopedics and rehabilitation in the developing and under-developed countries. In this study the etiological factors causing paraplegia from tuberculosis of spine are considered with a report of forty paralytic patients, treated with operation from January 1967 to March 1974. This analysis is concerned mainly with the radiological observations and measurements of various angles, and operative findings in children (12 cases) and adults (28 cases). In this study two groups are presented, one of the above patients (40 cases) and the other of controls (35 cases) which were selected at random from spine tuberculosis patients who were non-paralysed. They were compaired with the same level in children and adults. The spinal level of lesions was divided into four groups; upper-thoracic (T₁-T₄, 5 cases), mid thoracic (T₅-T₁₀, 18 cases), thoraco-lumbar (T₁₁-L₂, 14 cases). and lumbosacral (L₁-S₁. 3 cases). The extent of destruction of the involved vertebrae was divided into four groups from antero- posterior and lateral x-rays; very mild, mild, moderate, and marked. The destructive changes were moderate and marked in thg paralysed patients, but most case of the control group belonged to very mild and mild. The degree of displacement in the antero-posterior view which corresponds with subluxation or dislocation of the vertebrae was increased in the paraplegia group, but the χ²-test result was not significant. The displacement angle was measured in the antero-posterior view and it revealed from 0° to 13° with as average of 3.9°. but in control group it varied from 1° to 7° with an average of 1.8°. The angle was increased in children more than in adults is both paraplegia and control groups and the t-test showed a statistically high sigaificance in children, but not in adults. The kyphotic angle in the lateral view varied from 4° to 80° with an average of 31.1° in the paraplegia getup and 2° to 50° with an average of 23.4° for controls and the t-test was atatistically significant in children but not in adults. The wedging angle was also measured and varied from 10° to 88° with an average of 36° in paraplegics and in the control group the average angle was 26.2°, but contrary to other angles it was significant in adults but not in children. Operative findings were divided into seven groups according to the main material from the diseased focus; pus (32.5%). Gaseous material (20%). sequestrum (17.5%). degenerated disc and necrotic material (10% ), granulation tissue (7.5% ). bony spur formation (7.5% ). and granulomatous lesions (5%). In the child the main material was pus, Gaseous material. degenerated disc and necrotic material and granulation tissue. The radiological and operative findings lead us to conclude that; 1) The thoracic and thoraco-lumbar spine is most commonly involved. 2) Most cases show complete paralysis in both children and adults and most of them have flaccid paralysis. 3) Paravertebral abscess and sequestrum in x-ray corresponded well with operative findings. 4) Significant causative factors for the paralysis in children but not in adults are extent of destruction, displaced angle and kyphotic angle. In adults the wedging angle is the only statistically significant causative factor for the paraplegia in x-ray measurement. 5) In the operative findings, extrinsic causative factors are abscess containing pus, destructive disc or necrotic material, granulation tissue, aequestrum, Gaseous material, granulomatous lesions and bony: spur or ridge formation. Also subluxation and dislocation must be considered as extrinsic factors. The granulomatous lesions extending into the dura and fibrosis of the dura, and thickening and inflammatory changes of the meninges must be considered as an intrinsic factors. 6) The recovery of the paralysis occurs within six months in most of cases, and sensory recovery is more rapid than motor.