ABSTRACT
BACKGROUND: It is very important to apply a new technique of minimally invasive, firm fixation and antirotation in the treatment of lumbosacral degenerative diseases. OBJECTIVE: To provide theoretical basis for clinical application by biomechanical study on the treatment of lumbosacral vertebra instability with unidirectional axial fusion internal fixation system. METHODS: Six fresh adult lumbosacral specimens were selected, and the lumbosacral motion segments (L3-S5) were intercepted and divided into the following five groups: The intact normal control group (N group), bilateral isthmus fissure group (UN group), bilateral isthmus fissure + spur axial fusion internal fixation group (A group), bilateral isthmus fissure + axial screw fixation group (B group), bilateral spondylolysis + axial screw fixation alone + pedicle screw fixation on both sides group (C group). The three-dimensional motion range of flexion, lateral bending and rotation of segment L5/S1 in each group of internal fixation was compared with the axial compression resistance. RESULTS AND CONCLUSION: (1) The stability of fixed mode in A, B and C groups was better than that in the N group and the UN group under different directions of motion, and there were statistically significant differences between the groups (P 0.05). (3) In the left and right direction of rotation, the three-dimensional motion range of rotation in the A group was significantly reduced compared with that in the B group, and there was no significant difference between A group and C group (P > 0.05). (4) The lumbosacral vertebra unidirectional axial fusion internal fixation system has good biomechanical stability and strong anti-rotation ability, and is expected to be used in clinic.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the clinical curative effect of the modified Halo pelvic frame and surgery for the treatment of severe scoliosis with rigidity.</p><p><b>METHODS</b>From January 2004 to May 2010,50 patients with severe scoliosis patients with rigidity were treated in our hospital. Twenty-three patients were male and 27 patients were female, with a mean age of 10.8 years old, ranging from 4 to 16 years. Twenty-four patients were congenital scoliosis and 26 patiens were idiopathic scoliosis. The mean body height were (152.1 +/- 11.1) cm and the average Cobb angle of scoliosis and kyphosis were (91.8 +/- 14.5) degrees and (69.5 +/- 14.0) degrees respectively. All the patients were treated with three-stages modified Halo pelvic traction, the second stage anterior release and the third stage posterior correction. The amount of correction was determined by measuring the change of body height, the Cobb angles and correction rate of scoliosis as well as kyphosis before and after the operation.</p><p><b>RESULTS</b>The mean body height were correct to (158.5 +/- 10.5) cm. The average Cobb angle of scoliosis were correct to (30.8 +/- 7.9) degrees. The average Cobb angle of kyphosis were correct to (31.6 +/- 10.1) degrees. After the first stage, the average Cobb angle of scoliosis and kyphosis were changed with the mean of (30.4 +/- 6.6)% correction and (22.3 +/- 5.2)% respectively; after the second stage, the average Cobb angle of scoliosis and kyphosis were changed with the mean (26.7 -/+ 5.1)% correction and (21.2 -/+ 6.0)% respectively; the third stage, above data were (33.7 -/+ 7.2)% and (27.1 +/- 5.3)%. Correction rate of scoliosis and kyphosis were (66.5 +/- 7.2)% and (55.1 +/- 6.4)% respectively by the modified Halo pelvic frame traction and surgery. Body height, the Cobb angles and correction rate of scoliosis and kyphosis on radiographs were different in all stages (P<0.05).</p><p><b>CONCLUSION</b>Operative complications of severe scoliosis with rigidity can be reduced and better deformity correction and trunk balance achieved by the modified Halo pelvic frame traction and surgery.</p>