The Change Of Pelvis During Peak Height Velocity In Adolescent Idiopathic Scoliosis

Chapter2:Cervical Vertebral Maturation(CVM)Stage in Adolescent Idiopathic Scoliosis:An Alternative to Risser sign in Determining Peak Height Velocity(PHV).ObjectiveRadiographic methods in evaluating the skeletal maturity include Risser sign,digital skeletal age(DSA)score,Tanner-Whitehouse 3 score.They are eitherinappropriate or too complex for rapid use in a busy clinic setting.Cervical Vertebral Maturation stage is commonly used in Orthodontics but was less acknowledged in studies of spinal growth.The aim is to evaluate whetherthe Cervical Vertebral Maturation(CVM)stage could be used as an alternative to Risser sign in determining PHV.MethodsThis is a two-stage study.The inclusion criteria for AIS patients in stage I study were female,aged between 9-16 years old,with full spine images with clear visibility of cervical spine.Patients in stage Ⅱ study also need to have follow-up through CVM stage 2-4.The correlation between CVM and Risser sign was analyzed.The stature,arm span,trunk height,spinal length,and pelvic height were measured at each follow-up,the growth velocity of parameters(PaGVs)were also calculated.The PaGVs at CVM stage 2-4 were further compared.Results 170 AIS patients were included for stage I study(mean age 12.7years).The CVM stages were found to correlate strongly with Risser sign(r=0.85,p<0.01).In Risser 0 patients with closed TC,71%was CVM3.51 patients were included for stage Ⅱ study.The stature growth velocity averaged 5.4 cm/year in CVM2 patients and 6.3cm/year in CVM3 patients,significantly larger than that in CVM4 patients(3.3cm/year,both p<0.01);similarly,the growth velocity of arm span,trunk height and spinal length were also significantly higher in CVM3 patients compared to CVM2 and 4 patients.ConclusionsThe CVM stage could provide an alternative option for the assessment of skeletal maturity of subjects with idiopathic scoliosis.The CVM3 can be a new sign of PHV.The index needs to be verifiedin a multicenter study and in different ethnic groups.Chapter3:Changing pelvic incidence(PI)with the anatomical morphology in Adolescent Idiopathic ScoliosisObjective To evaluate the pattern of changing PI during peak skeleton growth in adolescence.We also studied whether the PI is associated with the anatomical morphology changes of pelvis and sacrum.MethodsThis retrospective longitudinal study recruited AIS patients,age between 9 and 18 years with full spine images and have at least 3 times follow-up.The radiological anatomical parameters were measured in each follow-up include pelvic incidence(PI),pelvic height(PH),pelvic width(PW),sacral width(SW),femoral head-sacrum(FH-S),sacrum-coccyx(S-C)length,sacrum-coccyx(S-C)distance and sacral curvature ratio.ΔParameter and growth velocity of each parameters were calculated.According to the skeletal maturity,all subjects were divided into 3 groups:Low Risser Group(Risser 0 to 1),Moderate Risser Group(Risser 1 to Risser 3)and High Risser group(Risser 3 to 5).Each group has 106 patients.We increased the male ratio to detect the gender difference.A total of 318 AIS patients were included in our study and there are 117 male patients.Descriptive analysis was conducted on the sample age,gender and measured parameter values with mean and standard deviation(SD).The intra-and inter-observer reliability analysis,the intraclass correlation coefficient(ICC)was also calculated.ResultsThe mean age of all subjects was 12.86 years and the mean Cobb angle was 26.67°at first visit.The peak growth velocity of PI is in Risser 1(female 1.5°/year and male 1.6°/year).The PI is also increasing rapidly in Risser 0.5(female 1.2°/year and male 1.5°/year)and Risser 2(female 1.1°/year and male 1.4°/year).When the Risser grade reaches 3 which was a sign of the end of skeleton growth,the PI still has increasing potential and it increases slower in Risser 4 and Risser 5.There showed significant correlation between ΔPI and Δage in the three group(p<0.05)and the correlation is stronger in Low Risser group and Moderate Risser group than that in High Risser group.There showed significant correlation between ΔPW and ΔPI in all groups while ΔPH andΔPI showed correlation only in Low Risser group.There showed significant correlation between ΔSW and ΔPI,ΔFH-S and ΔPI,ΔS-C length and ΔPI(p<0.05)except ΔS-C length in male Low Risser group andΔFH-S in female High Risser group and the Moderate Risser group had the strongest correlation.The ΔS-C distance and ΔS-C ratio didn’t show any correlation with ΔPI(p<0.05)expect the male of High Risser group.ConclusionPelvic incidence is increasing during skeleton growth at the age of 9 to 17.It has the peak growth velocity is in Risser 1 and remains growth potential in Risser 5.PI growth is correlated with pelvic height,femoral head-sacrum distance,pelvic width and sacral width.