Efficacy Of Posterior Hemivertebra Resection For Congenital Scoliosis With Different Three-dimensional Morphological Types And Different Age Groups

BackgroundHemivertebra is the most common cause of congenital scoliosis(CS).The classification of CS is of great significance for guiding intraoperative management and predicting disease outcome.The traditional CS classification is to classify the malformed vertebrae according to the anterior morphology of the malformed vertebrae on plain X-ray film.And CS is divided into failure of formation,failure of segmentation,or mixed abnormalities.However,the classification ignores the posterior morphology of the malformed vertebra and cannot accurately predict the progression of scoliosis due to hemivertebra.Recently,it has been found that hemivertebrae can be divided into unison hemivertebrae(UH)and discordant hemivertebrae(DH)through the three-dimensional reconstruction images of computed tomography(CT).This classification can accurately predict the progression of scoliosis due to hemivertebra.Without intervention,the scoliosis of UH can progress more rapidly than that of DH.However,it is not clear whether there is a difference in the progression of the two types of scoliosis after posterior hemivertebra resection.Most studies suggest that posterior hemivertebra resection should be performed early in CS patients due to hemivertebra,but the specific age group is the appropriate time for surgery is still uncertain.ObjectiveBy comparing the efficacy of posterior hemivertebra resection for CS patients with different three-dimensional morphological types and different age groups,to clarify whether there is a difference in the progression of the two types of scoliosis after posterior hemivertebra resection,and to explore the appropriate operation time of CS patients due to hemivertebra.Methods:The medical records and images of patients with CS due to single hemivertebra undergoing posterior hemivertebra resection combined with transpedicular instrumentation from January 2010 to January 2018 were reviewed and analyzed.Two classification methods were adopted in this study.First,according to the three-dimensional morphological type of hemivertebra,CS patients were divided into UH group and DH group.Second,according to the age of operation,CS patients were divided into infant group(≤5 years old)and child group(6-10 years old).Data on sex,operation time,intraoperative blood loss,length of hospital stay,location of hemivertebra,fusion levels,number of pedicle screws,complications,and last follow-up time were collected.The radiographic parameters from coronal and lateral standard plain radiographs of the entire spine obtained preoperatively,postoperatively(2 weeks after operation),and at the last follow-up were measured.The radiographic parameters included:Cobb angle of the segmental curve,clavicle angle(CA),thoracic kyphosis(TK),lumbar lordosis(LL),coronal balance(CB),sagittal vertical axis(SVA).The radiographic parameters,perioperative parameters and incidence of complications were compared between UH group and DH group,and between infant group and child group,respectively.ResultsA total of 42 patients with CS due to single hemivertebra were included in this study.The mean follow-up time was 2.61 years(2-4 years).The Cobb angle of the segmental curve was significantly improved postoperatively and at the last follow-up in UH group and DH group(P<0.05).Postoperatively,no significant differences were observed between UH group and DH group in the Cobb angle of the segmental curve(P=0.98),CA(P=0.74),TK(P=0.42),LL(P=0.82),CB(P=0.99)or SVA(P=0.53).At the last follow-up,no significant differences were observed between UH group and DH group in the Cobb angle of the segmental curve(P=0.60),CA(P=0.80),TK(P=0.19),LL(P=0.70),CB(P=0.17)or SVA(P=0.77).Compared with UH group,increased operation time(P=0.01)and intraoperative blood loss(P=0.04)were found in DH group.There was no significant difference in length of hospital stay(P=0.53),fusion levels(P=0.47)and number of pedicle screws(P=0.28)between UH group and DH group.There was no significant difference in the incidence of complications between UH group and DH group(P>0.05).The Cobb angle of the segmental curve was significantly improved postoperatively and at the last follow-up in infant group and child group(P<0.05).Postoperatively,no significant differences were found between infant group and child group in the Cobb angle of the segmental curve(P=0.77),CA(P=0.64),TK(P=0.65),LL(P=0.43),CB(P=0.96)or SVA(P=0.78).At the last follow-up,no significant differences were found between infant group and child group in the Cobb angle of the segmental curve(P=0.13),CA(P=0.82),TK(P=0.17),LL(P=0.06),CB(P=0.64)or SVA(P=0.49).The intraoperative blood loss in child group was significantly higher than that in infant group(P=0.01).There was no significant difference in operation time(P=0.84),length of hospital stay(P=0.66),fusion levels(P=0.18)and number of pedicle screws(P=0.19)between infant group and child group.There was no significant difference in the incidence of complications between infant group and child group(P>0.05).ConclusionsThere was no significant difference in the progression of scoliosis in congenital scoliosis with different three-dimensional morphological types after posterior hemivertebra resection.DH may lead to increased operation time and intraoperative blood loss due to its complex bony structure,suggesting that perioperative management of such patients should be strengthened.There was no significant difference in surgical outcomes between infants and children with hemivertebra.Therefore,for infants with hemivertebra,posterior hemivertebra resection can be delayed to 6-10 years old with close follow-up.