| Abstract: |
The autonomic nervous system may be considered as having adual function. The first function is to maintain the internal environ-ment of the body in a state that encourages optimal function of thevarious organ systems. The second function is to prepare the body toundertake extra-ordinary efforts in situations that threaten the body.Classically, two divisions of autonomic nervous system havebeen described. The parasympathetic nervous system which can beconceived as restorative system either before or after the stress&the sympathetic nervous system which prepare the body forfight or flight.Most of the sympathomimetic drugs in use today have mixedcc and B stimulating properties. Only the B-agonist isoproterenal andthe cc agonist phenylephrine and methoxamine are relatively puredrugs. The endogenous catecholamines are a perfect exam pIe. Dopaminehas ~1 - B1-, and dopamine receptor mediated effects. The dopaminereceptors are specifically activated by low doses of dopamine. Higherdoses of dopamine agonize first B-receptors and then, at higherdoses still, cc receptors. The other sympathomimetic arm nes all havemixed actions in two respectsdoses still, a:: receptors. Theyhave both a direct action on the receptor as well as the affect notedfor dopamine of releasing endogenous norepinephrine. The three most commonly used synthetic sympathomimetic, mephentermine(Wyamine), ephedrine and metaraminol (Ar ami ne) all have prominentindirect effect, although the former two agents are also direct-actingdrugs. A major prolbem in modern cardiovascular intensive care isthe support of the failing or ischemic heart without producing eithermarked tachycardia or peripheral vasodilation. 3. Lateral extracavitary in 13 patients (22%).4. Anterior transthoracic in 3 patients (5%).b. Spinal fixation (instrumentation): In 72 patients.1. Luque rectangle and sublaminar wiring in 37 patients (51.4%).2. Transpedicular rods-screw system in 30 patients.3. Body implant systems in 5 patients (6.9%).* Kaneda system in 3 patients (60%).* Z-plate system in 2 patients (40%).* Autologus bone grafting was applied in all surgically treated patients.* All patients wore external supportive orthoses on ambulation for 6 months.* Operative complications:- It was noted in 12/72 patients (16.7%).- Two patients (2.7%) developed deep back wound infection responded to antibiotics and debridement.- One patient (0.9%) developed C.S.F leak, required reoperation.- Three patients (2.9%) developed deep venous thrombosis.- Neither neurological deterioration nor mortality were recorded. Follow-up:Clinical follow-up ranged from 12-36 months with the mean was 21.6 months.a. Conservative group:1. Neurological recovery:- No neurological deficits in 12 patients (40%).- Incomplete neurological deficits in 13 patients (43.3%).- Complete neurological deficits in 5 patients (16.7%)2. Recovery index (mean % recovery rate) was 46.6%.3. Mean number of Yale Scale Score improvement was 0.6 score.4. Normal bladder recovery was found in 5 patients.5. Duration of maximum neurological improvement:- The range was 7-12 months.- The mean was 10.6 months.6. Mean recovery rate per month was 8.6%.7. Back pain:Four patients (13.3%) had severe back pain that required frequent use of orthoses. 8/30 patients (26.7%) had moderate back pain that required part time use of orthoses.b. Surgical group:1. Neurological recovery:- No neurological deficits in 36 patients (50%).- Incomplete neurological deficits in 29 patients (40.3%).- Complete neurological deficits in 7 patients (9.7%)2. Recovery index (mean % recovery rate) was 74.4%.3. Mean number of Yale scale score improvement was 1.5 score.4. Normal bladder recovery was found in 29 patients (67.4%).5. Duration of maximum neurological improvement:- The range was 2-8 months.- The mean was 4.9 months.6. Mean recovery rate per month was 14.2%.7. Back pain:Two patients (5.4%) had severe back pain that required use of orthoses most of time. Radiological data:a. Conservative group:1. Kyphotic angle:It increased as the mean initial angle was 16.7 degrees and at final follow-up it was 22.6 degrees with 35.3% increase.2. Vertebral collapse:Progressive vertebral collapse was noted in 14/22 patients (63.6%) with burst fracture. The mean duration for reaching the maximum collapse was 4.6 months.3. Canal compromise:Slow reduction of canal compromise as result of bone remodeling was noted in 14/22 patients with burst fracture. The range was 5-40% and the mean was 20.2%.b. Surgical group:1. Kyphotic angle:Spinal stabilization provided its correction from 25.3 degrees (mean initial) to 12.6 degrees (mean final) with 50.2% mean reduction.2. Vertebral collapse:No further vertebral collapse was noted as result of the supportive stabilization implants.Sagittal translation (Dynamic flexion/extension):No motion at the injured spinal level was noted at final follow up in both conservative and surgical groups.Hard ware complications:Screw break was noted in 7/30 patients (23.3%) with 3 or 4 screws break that required reoperation was noted in 3/30 patients (10%). 3 or 4 wire loop break of Luque rectangle was found in 4/37 patients (10.8%) and required reoperation.Outcome: Employment scale:Excellent outcome with return to pre-injury employment occurred in 44/72 patients (61.1%) in surgical group and in 50% in conservative group.B. Statistical correlations (level of significance P < 0.05): Wedge compression fractures had more tendency towards less neurological deficits. The difference was significant. No significant difference as regard burst fractures and extent of neurological deficits. Fracture dislocation had more tendency towards worst neurological deficits. The difference was significant. Significant difference has existed between the extent of neurological function and the reduced vertebral body with > 50% loss of vertebral height is the break point. Significant difference has existed between canal compromise and neurological function with 50% canal compromise is the break point. No significant difference has existed between kyphotic angle and the neurological function. Significant difference has existed between the initial Yale scale score and the percentage of recovery rate, the higher the Yale score the higher was the percentage recovery rate. Significant difference has existed between the initial Yale score and the duration of achieving maximum improvement. The higher the Yale score the shorter was the duration of improvement. Significant difference has existed between the initial kyphotic angle and its progression in conservative group. The greater the initial angle, the more was the progression. Significant difference has existed between initial percentage of reduced vertebral height and further vertebral collapse in conservative group with > 50% reduced vertebral height is the break point.The choice of the treatment modality:A. Surgical versus Conservative treatment: In patients without neurological deficits (Yale score 10), no significant difference has existed between surgical and conservative groups. In patients with mild neurological deficits (Yale scores 9,8), no significant difference has existed between surgical and conservative groups. In patients with moderate neurological deficits (Yale scores 7,6), significant difference has existed with better results in surgical than conservative group. In patients with severe neurological deficit (Yale scores 5-1), high significant difference has existed with better results in surgical than conservative groups. In patients with complete neurological deficits (Yale score 0), no significant difference has existed between surgical and conservative groups. Patients who had kyphotic angle up to 20 degrees, no significant difference has existed between surgical and conservative groups. Patients who had kyphotic angle more than 20 degrees, significant difference has existed with better results (back pain) in surgical than conservative groups.B. Selection of the surgical procedures: Neural decompressive procedures:Lateral extracavitary and anterior transthoracic decompressive approaches gave better results than laminectomy and transpedicular approaches. The difference was significant. Spinal stabilization techniques:Transpedicular and lateral vertebral body fixation had better results than Luque rectangle and sublaminar wiring with significant difference.
|
|
|