| Background:Ankylosing spondylitis(AS)is prone to rigid and fixed thoracolumbar kyphosis deformity in the late stage of the disease.The typical deformity is the reduction or disappearance of lumbar lordosis,the increase of thoracolumbar kyphosis,and the forward inclination of head and neck.Some patients are complicated with cervical rigidity and limited hip joint movement,resulting in the limited activity of patients such as standing,walking and head up,At present,spinal osteotomy is the most effective method to correct as thoracolumbar kyphosis.However,the way,location and degree of spinal osteotomy are closely related to the effect of postoperative correction.Simple empirical osteotomy often can not obtain ideal correction.Therefore,preoperative individualized osteotomy design and intraoperative accurate osteotomy are the necessary premise to complete the expected correction effect.In recent years,digital medical orthopedics has made great progress in preoperative planning and intraoperative precise implementation,which also provides the possibility of precise correction for patients with ankylosing spondylitis kyphosis.Objective:By analyzing the changes of spine pelvic imaging parameters and quality of life scores of patients with thoracolumbar kyphosis before and after operation,to evaluate the feasibility,accuracy and clinical effect of digital technology in spinal osteotomy.Methods:The patients with thoracolumbar kyphosis treated by osteotomy and orthopedics in the spine and spinal cord surgery of Henan Provincial People’s Hospital from January 2019 to September 2021 were analyzed retrospectively,16 males and 2 females,with an average of 32.2 ± 7.9 years(range 19 to 46years),According to AS301,there were 3 cases of type I,3 cases of type IIA,2 cases of type IIB,6 cases of type IIA and 4 cases of type IIB.Surgimap spine software was used to design the osteotomy scheme and osteotomy range before operation,and mimics software was used to accurately the osteotomy angle.Finally,3D printing technology was used to reconstruct the wedge osteotomy block and guide the accurate osteotomy during operation.All operations were performed according to the preoperative simulated osteotomy angle.The operation time,intraoperative bleeding and complications were observed.The height of osteotomy space at the posterior edge of vertebral body during operation and the change of angle between upper and lower vertebral endplates of upper and lower vertebral bodies were recorded.The general appearance photos were taken before operation,and the full-length frontal and lateral X-ray examination of the spine was taken before operation,2 weeks after operation and at the last follow-up.The maxillary eyebrow angle(CBVA),total spinal kyphosis angle(GK),thoracic kyphosis angle(TK),thoracolumbar kyphosis angle(TLK),lumbar kyphosis angle(LL),pelvic inclination angle(PT),pelvic incidence angle(PI),sacral inclination angle(SS)The difference between pelvic incidence angle and lumbar lordosis angle(PI-LL)and sagittal balance distance(SVA)were used to evaluate the improvement of spine pelvis and jaw eyebrow angle.The clinical efficacy was evaluated by Oswestry dysfunction index(ODI)and SRS-22 score,and the surgical complications during follow-up were recorded.Results:The operation duration was(414.7 ± 39.7)min and the amount of intraoperative bleeding was(1321.9 ± 342.4)ml.Single segmental osteotomy was performed in 8 cases and double segmental osteotomy in 10 cases.The osteotomy segment was located in T12 1 case,L1 1 case,L2 2 cases,L3 3cases,T11/T12 1 case,T11+L2 2 cases,T12+L3 3 cases and L1+L3 5 cases.Each patient was followed up for(12.7±6.2)months.CBVA was(34.2±14.2)°,(12.5±4.1)°and(15.2±4.5)°respectively before operation,2 weeks after operation and at the last follow-up;GK was(69.2±28.6)°,(38.7±13.6)°and(40.1±11.5)°respectively;TK was(54.6±18.5)°,(37.6±10.5)°and(41.2±9.5)°respectively;TLK was(35.3±15.9)°,(19.4±8.1)°,(21.2±7.8)°and LL were(-2.6±21.2)°,(-38.5±13.9)°and(-38.8±8.6)°respectively;PT was(39.4±12.6)°,(21.5±9.5)° and(25.8±7.8)°respectively;SS was(12.5±7.6)°,(26.4±7.6)° and(27.1±7.5)° respectively;PI-LL were(38.1±12.6)°,(9.3±7.5)°and(10.2 ± 9.9)° respectively;The SVA were(182.3 ± 49.4)mm,(39.5 ± 11.3)mm and(45.3 ± 12.6)mm respectively.Compared with that before operation,it was significantly improved 2 weeks after operation and at the last follow-up(P<0.05).There was no significant change in the data at the last follow-up compared with the two weeks after operation(P>0.05).The PI values at three different time points were(48.8±12.3)°(47.8±11.8)°and(48.5±12.7)°respectively,with no difference(P>0.05);At the last follow-up,ODI and SRS-22 score were evidently improved(P<0.05).A total of 28 wedge-shaped osteotomy blocks were reconstructed by digital software,and the accuracy of osteotomy height and osteotomy angle were(93.5±3.3)%、and(93.1±2.1)% respectively.Among them,2 patients had cerebrospinal fluid leakage during operation,2 patients had sagittal displacement during the closure of osteotomy space,but there was no nerve injury,3 patients had abdominal tension pain after operation,and1 patient had incision infection,which recovered well after symptomatic treatment.At the last follow-up,There was no failure or fracture of internal fixation,and the osteotomy healed well.Conclusions:Digital technology can provide individualized osteotomy scheme design for patients with AS thoracolumbar kyphosis before operation,guide accurate osteotomy during operation and improve postoperative satisfaction. |
