Applied Research Of All Pedicle Screws And CoCr Rods In The Orthopedic Surgery Of Adolescent Idiopathic Scoliosis

【Purpose】 Scoliosis is a three-dimensional spinal deformity in coronal place, sagittal place and transverse section, idiopathic scoliosis(IS) is the most common.The etiology of idiopathic scoliosis are still not totally clear,so there is no radical therapy in etiology.After the mid-19 th century,people began to attempt to use the surgical approach for the treatment of scoliosis and trying to improve scoliosis symptoms and prevent their progress.Due the development of medical,the awareness about spinal deformities become deeper,the orthopaedic technology of scoliosis is improving.we can obtain satisfactory results in the orthopedic of scoliosis.But there is still space for further improvement for the correction of scoliosis. The appearance of spinal internal fixation system greatly improve the correction rate.The correction result become more precisely.The invention of all pedicle screws further improve the correction rate and has been widely accepted and applied.However,the deformity of scoliosis is not exist in the coronal plane,also exist in the sagittal plane.Researchers paid more attention to the correction of coronal plane before and ignored the sagittal plane.How is the all pedicle screw system effect the orthopedic of AIS in the coronal and sagittal plane? Cobalt-chromium alloy has greater strength and hardnes, highest potential of plastic deformation witch can provide powerful orthopedic force in theory.Whether Co Cr rods improve the orthopedic effect? This issue use a retrospective method to analysis the surgical results of AIS receiving orthopedic surgery:1.the effect on the coronal and sagittal plane using all pedicle screw system to treat AIS.2.the surgery results using Co Cr rods in orthopedic surgery of AIS.【Materials and Methods】 Part Ⅰ:We choose 98 AIS patients of Lenke 1 type who received the treatment of all pedicle screw system.We measure and record the radiographic parameters of main curve angle,C7-CSVL, Shoulder height difference in coronal plane,TK,TLK,LL,SVA in sagittal plane preoperative, postoperative and at final follow-up.We use paired t test for data analysis and compare the effect of orthopedic. Part Ⅱ:We choose 134 AIS patients who received the treatment of all pedicle screw system but using Co Cr rods and titanium rods to fix respectively.There are 33 patients using Co Cr rods and 101 patients using titanium rods.We measure and record theradiographic parameters of main curve angle in coronal plane,TK,TLK,LL in sagittal plane preoperative, postoperative and at final follow-up.They filled out the SRS-22 at the same time.We use X2 test to analysis the constitution of scoliosis typing,two-sample t test to analysis radiographic parameters preoperative, postoperative and at final follow-up. We use two-sample t test to analysis the difference of the SRS-22 scores between the two groups,paired t test to analysis the difference of the SRS-22 scores preoperative and postoperative.【Results】 Part Ⅰ:The Bending Correctional Rate of patients is 50.69±19.22%.The major curve cobb angle in the coronal plane decreased from 46.92± 6.68° to 15.24± 6.45°. The correction rate was 67.91± 11.52%.The C7-CSVL postoperative decreased from 11.41 ± 5.61 mm to 10.10 ± 4.66 mm and the houlder height difference was reduced from 13.45 ± 7.99 mm to 11.96 ± 5.87 mm, but no significant difference between preoperative and postoperative. In the sagittal plane, T5-T12 kyphosis angle decreased from 18.88± 10.45° to 16.31± 6.53°, and reduced to 14.94± 5.27°at last follow-up.There are statistically significance(P<0.05) between preoperative and postoperative, postoperative and final follow-up. There is no significant difference among preoperative postoperative and the last follow-up in T11-L2 lordosis. L1-L5 lordosis decreased from 45.04± 13.76° preoperative to 37.49± 11.62° postoperative, and 38.23± 10.87° at last follow-up.There is significant difference(P<0.05) between preoperative and postoperative,but no significant difference(P>0.05) between postoperative and final follow-up.There is no significant difference(P> 0.05) between The SVA parameter preoperative,postoperative and last follow-up. Part Ⅱ:There is no significant difference(P>0.05) between the two groups of patients in the parameters of age, Risser sign, scoliosis typing constituent ratio, major curve Cobb angle, flexibility assessment, thoracic kyphosis, thoracolumbar lordosis, lumbar lordosis before surgery.The major curve Cobb angle in the first group(cobalt chrome rods Group) corrected from 48.30± 10.75° preoperative to 14.72± 5.01° postoperative, and 16.12±5.48° at last follow-up. The major curve Cobb angle in the second group(titanium rod group) correction from 51.90 ± 14.40 °preoperative to 17.37 ± 12.10° postoperative, and 20.25 ± 9.56°at last follow-up. There are significant difference(P <0.05) between the two groups at the major curve Cobb angle parameter preoperative and at last follow-up. The thoracic kyphosis of the first group increases from 20.85 ± 12.09° to 22.19 ± 5.44° postoperative, 21.27 ± 5.34° at last follow-up.The thoracickyphosis of the second group decreased from 20.02 ± 13.74°to 18.02 ± 7.98° postoperative, 16.53 ± 7.98° at last follow-up. There is significant difference(P <0.01) in thoracic kyphosis between two groups postoperative and at final follow-up.There are no significant difference(P> 0.05) in thoracolumbar lordosis and lumbar lordosis between the two groups postoperative and at final follow-up. In the health-related quality of life, there is no significant difference in SRS-22 scores between the two groups preoperative in different domains. At last follow-up, compared with the preoperative, the two groups were decreased in the function domain(P<0.05) and has no significant difference(P> 0.05) in the pain domain.The scores improve in the self-image/appearance domain, mental health domain, treatment satisfaction domain, and the difference is significant(P <0.05). At the last follow-up, there is no significant difference(P> 0.05)in the scores between two groups of patients in different domains.【Conclusion】 1.All pedicle screw system can provide powerful orthopedic force and improve the orthotic effect of adolescent idiopathic scoliosis. 2. All pedicle screw system can reduce fusion segments, retain the motion segment as much as possible.It is safe to implant the pedicle screw. 3. We can get good results in the coronal plane using all pedicle screw system.In the sagittal plane, howerver,it can cause the reduction of thoracic kyphosis,resulting in the reduction of physiological curve postoperative, which is a problem can not be ignored. 4. Using Co Cr rods for posterior spinal orthopedic fixation in adolescent idiopathic scoliosis can provide greater force in the coronal plane. 5. AIS patients have better flexibility and the curve angle is small.The effect of using cobalt-chromium compared to titanium rods is significant statistically, but the real difference is small. 6. Using Co Cr rods for posterior spinal orthopedic fixation can restore the sagittal plane better and prevent the reduction of thoracic kyphosis and maintain the orthopedic effect better. 6.The SRS-22 scores of the 2 groups improved compared to the scores preoperative, but there was no significant difference between the two groups.The application of Co Cr rods which are stronger and stiffer will not bring a greater negative impact on the quality of life after operation.