THE EFFECT OF CERVICAL TRACTION COMBINED WITH ROTATORY MANIPULATION ON CERVICAL NUCLEUS PULPOSUS PRESSURES

Objective: To study experimentally the effect of cervical traction com bined with rotatory manipulation on the pressure of the cervical nucle us pulposus. Design: Randomized experimental study. Setting: Institute of Clinical Anatomy and Biomechanics, the First Military Medical Univ ersity, GuangZhou, China. Subjects: Twelve fresh cervical spines, from C7 to occipital bone, were obtained from cadavers of patients who had died from acute brain death. Interventions: State A: under different traction forces, the cervical spine was rotated. State B: the cervical spine was rotated first and then tractioned. State C: the cervical sp ine was tractioned and rotated simultaneously. Main Outcome Measures: The cervical spine was tractioned and rotated by the Material Test Sys tem (MTS), and pressures of the cervical nucleus pulposus of C3-4, C4- 5 and C5-6 were measured using pressure sensors. Results: (a) When the traction force increased, the pressure fell continuously in the 200-N tractioned spines; the pressure increased slightly when the sample wa s rotated. (b) The pressure fell to a certain extent when the state of cervical spine was restored. (c) In state A, the pressure fell obviou sly and increased slightly under a 200-N traction force and then the s ample was rotated; in state B, the pressure first increased to a certa in extent and then fell slightly and in state C, the pressure underwen t no change in the main. Conclusions: The results of this research sug gest that rotatory manipulation of cervical spine under traction was t he safest of the three procedures and the traction force used in clini cal treatment may be a little smaller.