Global Sagittal Alignment After Surgical Correction Of Isthmic Spondylolisthesis And Its Clinical Significance

ObjectiveThis study is a retrospective multi-centre analysis of changes in global sagittal alignment after surgical correction of L4 or L5 isthmic spondylolisthesis.To provides the theories for the clinical treatments through analyzing the global sagittal alignment of isthmic spondylolisthesis in adults before and after operation and identifying the significance of parameters in isthmic spondylolisthesis and the influences on the clinical outcome.MethodsA retrospective multi-centre study of 60 cases with L4 or L5 isthmic spondylolisthesis admitted in our hospital from January 2004 to January 2009,including 26 males and 34 females with an average ages of 44 years.The recruited cases was conducted with the following inclusion criteria(1)A diagnosis of L4 or L5 isthmic spondylolisthesis according to the classification of Wiltse-Newman- Macnab,(2)an age between 18 to 60 years,(3)The availability of a standing lateral radiograph of global spine and pelvis in which the C7 to S1 and both femoral heads were visible.And subjects with any previous spine surgery,associated musculoskeletal syndrome,or significant lower limb discrepancy(2 cm) were excluded from the study.Normal matched control is 30 health adults, including 15 males and 15 females,without previous spine diseases.All radiographs were then measured by the same experienced individual.The parameters include:1.thoracic kyphosis,(TK),2.lumbar lordosis(LL),3. Pelvic incidence(PI),4.Sacral slope(SS),5.Pelvic tilt(PT),6. Lumbosacral angle(LSA),7.The horizontal distance between C7 PL and the posterior corner of the sacrum(SC7D),8.Sacro-femoral distance(SFD) 9.T9 tilt.On lateral view radiographs,the grade of spondylolisthesis was determined by measuring the ratio between the displacement and the total width of the vertebral endplate:grade 1,up to 25%;grade 2,up to 50%; grade 3,up to 75%;and grade 4,up to 100%.The patients all do Oswestry barrier score before and after operation.Student's t test and Pearson's correlation coefficients were used for the analysis of parameters.Results There were significant differences between pre-operative and postoperative cases of isthmic spondylolisthesis in degree of slip,SS,LL,LSA,TK,T9tilt,SC7D/SFD ratio(P＜0.01),there were the same outcome between pre-operative cases of isthmic spondylolisthesis and health adults group(P＜0.01);There were no significant differences between post-operative cases of isthmic spondylolisthesis and health adults group(P＞0.05);There were no significant differences between pre-opperative cases and post-operative cases of isthmic spondylolisthesis in PI angle,but there was very significant differences between cases of spondylolisthesis and health adults group(P＜0.01);There were significant correlation coefficients in PI,SFD,LSA,T9 tilt and degree of slip.There were obvious correlation coefficients between PI and SS,T9 tilt. Significant linear correlations were found between each single adjacent shape parameter(PI and LL,P＜0.01 LL and TK,P＜0.01);as well as between oswestry barrier score and LSA(P＜0.01).ConclusionIn conclusion,the evidence presented supports that the sagittal imbalance of isthmic spondylolisthesis patients can be improved after surgical correction;LL and LSA conduce to predict and evaluate the effect of operation,and better guide for therapy.