Clinical Efficacy Evaluation Of 3D Printing-assisted SRS-Schwab Level Ⅳ Osteotomy For Post-traumatic Thoracolumbar Segment Kyphosis

BackroundEarly improperly treated or untreated thoracolumbar segment fractures often cause thoracolumbar kyphosis,and most post-traumatic thoracolumbar kyphosis is a rigid kyphosis with poor conservative treatment results,and surgery is often the ultimate treatment for most patients.Currently,pedicle subtraction osteotomy(PSO)is the most common technique used clinically to correct post-traumatic kyphosis because it does not lengthen the anterior column,reduces the risk of anterior surgery,and provides satisfactory orthopaedic results[1].However,the results of PSO are not always satisfactory because PSO preserves the potentially damaged superior intervertebral disc during the procedure.In 2014,Schwab et al[2]systematically classified osteotomies into six levels,based on the anatomical classification,among which PSO belongs to Schwab level Ⅲ osteotomy,and compared with Schwab levelⅢ osteotomy,Schwab level Ⅳ osteotomy increases 1 complete resection of the adjacent disc,and the discs of patients with post-traumatic thoracolumbar segment kyphosis are easily damaged during thoracolumbar fracture.In addition,with ageing and biological stress,the disc is susceptible to disc degeneration,intervertebral space narrowing,and vertebral wedging in late stages.Subsequently,the Schwab level Ⅳosteotomy was gradually applied to treat post-traumatic kyphosis.At present,spine surgeons mainly refer to preoperative imaging data when planning surgery and lack of comprehensive knowledge and understanding of kyphosis,and different patients have different osteotomy segments and osteotomy angles,which could readily injure the crucial structures like neuro in the operation[3].With the continuous development of osteotomy orthopaedic surgery and internal fixation techniques,the key to successful orthopaedic surgery is to accurately osteotype the bone,obtain the best osteotomy solution,and restore the patient’s sagittal balance.For the past few years,3D printing technology is commonly used in the field of orthopedics with great success.However,few studies have been reported on the use of 3D printing-assisted SRS-Schwab level Ⅳ osteotomy for post-traumatic thoracolumbar segment kyphosis.In this study,we evaluated the clinical efficacy of 3D printing-assisted SRS-Schwab level IV osteotomy in the therapy of patients who had a thoracolumbar fracture associated with kyphosis.And then we compared the conventional SRSSchwab Ⅳ osteotomy with 3D printing-assisted SRS-Schwab level Ⅳ osteotomy during the same period to analyze the advantages and effbectiveness of 3D printing-assisted SRS-Schwab level Ⅳ osteotomy for further clinical guidance.ObjectiveTo probe the clinical results of 3D printing-assisted SRS-Schwab level Ⅳosteotomy for post-traumatic thoracolumbar segment kyphosis.MethodsWe chose some medical information from January 2016 to June 2019 by retrospectively analyzing patients who received treatment for post-traumatic kyphosis at our Hospital,and a total of 21 cases were treated with 3D printing-assisted SRS-Schwab level Ⅳ osteotomy,which was called the 3D group.During the same period,we also chose 20 patients with traumatic kyphosis treated at our Hospital,and these patients were treated with conventional SRS-Schwab level Ⅳ osteotomy as the conventional group.Afterwards,the clinical outcomes of 3D printing-assisted SRS-Schwab level Ⅳ osteotomy and conventional SRS-Schwab level Ⅳosteotomy surgical approaches were contrasted with each other.The surgical time,the hemorrhage quantity and related undesirable effect were recorded.We took full length and upright forward lateral X-ray of the spine in the erect position before surgery,2 weeks after surgery and at the last follow-up visit.We measured the localized Cobb angle,pelvic tilt,pelvic incidence,sacral tilt,and sagittal vertical axis.Visual analogue score and Oswestry dysfunction index were writed for diverse periods.SPSS26.0 was used to analyze the data.ResultsAll groups completed the surgery successfully,and no undesirable effect like nerve damage emerged.The surgical time and the hemorrhage quantity of the 3D group were prominently less(P<0.05).Versus the preoperative,the local Cobb was prominently lessened in both groups at 2 weeks after surgery and at the last follow-up visit(P<0.05),and the extent of reduction was greater in the 3D group(P<0.05).Versus the preoperative,SVA and PT were prominently lower(P<0.05)and SS were prominently higher(P<0.05)in both groups at 2 weeks postoperatively and at the last follow-up visit,but the differences in SVA,PT,and SS were not prominently significant between the two groups at the same time points(P>0.05).Patients in all groups had similar amelioration in VAS and ODI scores at different time.ConclusionsThe 3D printing-assisted SRS-Schwab level Ⅳ osteotomy for post-traumatic thoracolumbar segment kyphosis can achieve content clinical utility with well rectification of kyphosis and can lessen the hemorrhage quantity and the time.The 3D printed model can visualize the shape of the post-traumatic thoracolumbar segment kyphosis vertebra and its spatial relationship with the nearby tissues,and pre-simulate the osteotomy orthopedic operation before the surgery,which can offer a direction for the osteotomy orthopedic operation.