Lenke 1A型青少年特发性脊柱侧凸矫形术中远端融合椎选择的"鼓楼规则"

The"Gulou Rule"for the selection of lowest instrumented vertebra in adolescent idiopathic scoliosis with Lenke 1A curves

目的提出Lenke 1A型青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)矫形术中的下端固定椎选择的"鼓楼规则",并与"远端充分触及椎(last substantially touching vertebra,LSTV)规则"的临床效果进行比较。方法根据南京鼓楼医院既往关于Lenke 1A型AIS患者矫形术中下端固定椎选择的回顾性研究,筛选与下端固定椎选择相关的指标并结合临床经验提出下端固定椎选择的"鼓楼规则"。连续收集2021年1月至2022年1月于南京鼓楼医院接受手术治疗的Lenke 1A型患者189例,男29例、女160例,年龄(14.9±2.8)岁(范围10~18岁)。均接受脊柱后路矫形融合术治疗,根据收治顺序选择下端固定椎(单号采用传统"LSTV规则"、双号采用"鼓楼规则")。术前、术后即刻和末次随访时测量患者的影像学参数,包括融合节段数,上胸弯、胸弯和腰弯的Cobb角及矫正率,冠状面平衡和矢状面平衡等参数,记录远端叠加现象等并发症的发生率。结果下端固定椎选择的"鼓楼规则":当Risser≥3级、主弯长度≤8个节段、LSTV近端一个节段(LSTV-1)旋转≤Ⅰ度、LSTV-1偏移中线<20 mm、术前冠状面平衡<10 mm且LSTV-1与LSTV间椎间盘在Bending像上可双向开口,此时下端固定椎可选择LSTV-1;如不符合以上条件,下端固定椎应选择LSTV。最终120例纳入研究,男21例、女99例,年龄(15.1±2.4)岁(范围10~18岁),每组各60例。术后随访至少2年,"LSTV规则"组随访时间为(31.0±5.4)个月,"鼓楼规则"组为(30.8±5.1)个月。"鼓楼规则"组下端固定椎主要位于T12、L1节段,"LSTV规则"组下端固定椎主要位于L1、L 2节段,两组的差异有统计学意义(P=0.004)。"LSTV规则"组融合节段为(10.5±1.7)个节段,"鼓楼规则"组为(9.7±1.5)个节段,差异有统计学意义(t=2.760,P=0.003)。末次随访时"LSTV规则"组和"鼓楼规则"组主弯矫正率分别为74.8%±10.5%和73.2%±12.3%,差异无统计学意义(t=0.779,P=0.219);"LSTV规则"组远端叠加现象发生率为15%(9/60),"鼓楼规则"组为17%(10/60),差异无统计学意义(χ2=0.063,P=0.803)。结论对于Lenke 1A型患者采用"鼓楼规则"与"LSTV规则"指导下端固定椎选择均可取得满意的矫形效果,根据"鼓楼规则"选择下端固定椎可减少远端融合节段。

Objective To develop a set of lowest instrumented vertebra(LIV)selection criteria for adolescent idiopathic scoliosis(AIS)with Lenke 1A curves named as"Gulou Rule",and compared with the traditional"last substantially touching vertebra(LSTV)Rule".Methods Based on our previous retrospective studies about LIV selection,as well as our clinical experience,the key parameters associated with LIV selection were found out and quantified to form the"Gulou Rule".A prospective consecutive collection of 189 Lenke 1A cases(male 29 cases,female 160 cases)who underwent posterior spinal fusion surgery in our clinic from January 2021 to January 2022 were recruited,with an average age of 14.9±2.8(range 10-18)years old.They were divided into 2 groups according to the enrollment number(odd or even number).Patients with odd numbers were guided by the"LSTV Rule",while those with even numbers followed the"Gulou Rule"for the selection of LIV.The duration of follow-up was at least two years.Radiographical parameters were measured preoperatively,immediately postoperatively,and at the final follow-up,including numbers of fused segments,Cobb angle of proximal thoracic curve,main thoracic curve and lumbar curve,correction rate,coronal and sagittal balance parameters.The incidence of distal adding-on at the last follow-up was recorded.Results The"Gulou Rule"was defined as follows:when Risser≥3,main curve length≤8 segments,one level proximal to LSTV(LSTV-1)rotation≤I degree,LSTV-1 deviation from the CSVL<20 mm,preoperative coronal balance<10 mm,and the intervertebral disc between LSTV-1 and LSTV opens bidirectionally on bending films,the LIV can be selected as LSTV-1;if these conditions are not met,LIV should be selected as LSTV.At last,120 patients(male 21 cases,female 99 cases)were enrolled in the study with at least a 2-year follow-up,with an average age of 15.1±2.4(range 10-18)years old.Each group had 60 patients,and the average duration of follow-up was 31.0±5.4 months for the"LSTV Rule"group and 30.8±5.1 months for the"Gulou Rule"group.The LIV in the"Gulou Rule"group was on average at the T12 and L1 level,where as in the"LSTV Rule"group,it was at the L1 and L2 level(P=0.004).The"LSTV Rule"group had an average fused segments of 10.5±1.7,while the"Gulou Rule"group was significantly lower with 9.7±1.5 segments(t=2.760,P=0.003).At the last follow-up,the main curve correction rates were 74.8%±10.5%and 73.2%±12.3%,respectively,with no significant difference(t=0.779,P=0.219).The incidence of distal adding-on phenomenon was 15%in the"LSTV Rule"group and 17%in the"Gulou Rule"group,with no significant difference between the two groups(χ2=0.063,P=0.803).Conclusion For Lenke 1A AIS patients,both the"Gulou Rule"and the"LSTV Rule"for guiding LIV selection can achieve satisfactory correction outcomes.Choosing LIV based on the"Gulou Rule"allows for the preservation of distal fusion segments and demonstrates better clinical applicability.