Imaging And Clinical Study Of Lumbar Spondylolisthesis

The first part:The characteristics of morphological and anatomical parameters of adult degenerative spondylolisthesisObjective To analyze and compare spino-pelvic andanatomical parameters of degenerative spondylolisthesis（DS） patients and to assess the differences between the L4 & L5 DS.Methods 124DS patients（20 males,104 females） with a mean age of 49.3 years（range, 46-70 years） and 75 normal adults（24 males,51 females） with a mean age 47.7 years （range,43-69 years） were recruited in this retrospective study.DS group contained 103 L4 cases and 21 L5 cases. Spinopelvic and anatomical parameters were analyzed on preoperative full spine x-rays in a standardized standing position. Spinopelvic parameters were measured as following:pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, thoracic kyphosis, and positioning of the C7 plumb line. Anatomicalparameters were measured as following:iliac crest height, sacral table angle, L4 and L5 transverse process length, L4 and L5 transverse process width, L4 and L5lumbar index. Differences in sagittal parameters among groups were analyzed by using independent samples t-test.Results The PI, PT, SS, LL and SVA were 57.9±10.3°,18.4°±7.4°,39.9°±8.3°, 54.7°±10.9° and 28.6mm±18.2mm respectively, which were significant higher in subjects with DS than those in the control groupy（43.7°±11.6°,13.7°±6.9°, 30.2°±8.2°,48.3°±10.1° and 13.1mm±19.9mm）. Compared with the control group, the TPW of L4 （0.17 vs 0.25, P＜0.05） and L5（0.19 vs 0.24, P＜0.05） were extremely shorter, the STAwere moreinclined （98.5° vs 90.3°, P＜0.05） and the LI of L4（0.84 vs 0.94, P<0.05） and L5 were lower（0.83 vs 0.92, P＜0.05） in the DS group. On comparison between the L4 and L5 DS groups, there was no difference in all the spino-pelvic parameters （p>0.05）; Anatomicalparameters such asSTA, TPL and TPWdemonstrating no significant difference,while the ICH were significant higher in L4 DS group（0.68 vs-1.1, P＜0.05）.Conclusion Morphological and anatomical parameters might be related to the occurrence of degenerative lumbar spondylolisthesis, while the level of vertebral body slippage were more likely associated with the ICH, the ilium with a higher iliac crest act a role in protecting L5 from slipping, which predispose the L4 vertebra to slip.The second part:Effects of varying degree of reduction on clinical outcomes in patients with low grade degenerative spondylolisthesisObjective To evaluate the effect of varying degrees of reduction on the the radiographic and clinical outcomes in patients with grade I and II degenerative spondylolisthesis.Methods We retrospectively reviewed a consecutive cohort of 96 patients with degenerative lumbar spondylolisthesis （Meyerding grade I or II） who received TLIF between January 2008 and may 2013. They were followed up for at least 2 years. According to the reduction results, all patients were divided into reduction group or partial reduction group. There were 49 patients in reduction group,including 11 males and 38 females, with the average age of 55.7 （range 39～69） years,27 patients were classified as degree I spondylolisthesis and 22 patients were classified as degree II spondylolisthesis; 47 patients were in the partial reduction group, including 8 males and 39 females, with the average age of 54.6 （range 40～67） years,39 patients were classified as degree I spondylolisthesis and 28 patients were classified as degree II spondylolisthesis.Disc height, slip angle and slip ratio were measured to evaluate the radiographic outcomes, the fusion rate were evaluated at 1 year postoperatively and at the latest follow up. Oswestry disability index （ODI） and Numerical rating scale （NRS） were collected to evaluate the clinical results. The radiographic measurements and clinical indexes were recorded at pre-and post-operation and at last follow up.Results Operation time （179.3min±47.2min vs 182.3min±55.1min, P>0.05） and estimated blood loss （596.3ml±101.7ml vs 620.5ml±25.9ml, p>0.05） showed no defference between the two groups. The complications related to instrumentation had no significant difference between groups till the latest follow up. There were no difference between reduction group and partial reduction group in terms of disc height, slip angle and slip ratio preoperatively. Postoperative radiographic results showed that patients of both groups had significant improvement, while there were no significant difference between groups in terms of disc height and slip angle. The fusion rate between the two groups showed no significant difference at 1 year postoperatively and at the latest follow up （P>0.05）. The ODI and NRS scores were significant improved after surgery and at latest follow up, while demonstrating no significant difference between the two groups.Conclusion No difference were observed between reduction group and partial reduction group in terms of clinical outcome and fusion rate for low grade degenerative spondylolisthesis patients undergoing TLIF.The third part:Transforminal lumbar interbody fusion versus posterolateral lumbar fusion in treatment of lumbar spondylolisthesis: A mid-term follow-up studyObjective To compare the radiographic and clinical results of transforminal lumbar interbody fusion （TLIF） and posterolateral lumbar fusion （PLF） in the treatment of low-grade lumbar spondylolisthesis.Methods We retrospectively reviewed a consecutive cohort of 167 patients with lumbar spondylolisthesis （Meyerding grade I or II） who received either TLIF or PLF between January 2007 and January 2012 and had a minimum follow-up of 2 years. There were 72 cases with degenerative spondylolisthesis and 95 with isthmic spondylolisthesis, and 103 cases at L4/L5 and 64 at L5/S1, respectively. Among them, 75_patients underwent PLF, including 19 males and 56 females, with the average age of 56.1 years,92 patients underwent TLIF, including 27 males and 65 females, with the average age of 55.7 years. Disc height, slip angle and slip ratio were measured to evaluate the radiographic outcomes. Oswestry disability index_ODI, Numerical rating scale （NRS） and the MOS item short from health survey_SF-36 were collected to evaluate the clinical results. The radiographic measurements and clinical indexes were recorded pre-_and post-operation and at last follow up.Results Shorter operation time （175.3min±46.2min vs.228.3min±52.1min, P<0.01） and less estimated blood loss （415.3ml±101.7ml vs.620.5ml±125.9ml, p<0.01） were observed in PLF versus TLIF. The complications related to instrumentation had no significant difference between groups in mean follow-up of 35 months （Range,24-84 months）. There were no difference between TLIF group and PLF group in terms of disc height, slip angle and slip ratio preoperatively. Postoperativeradiographic results showed that patients of both groups had significant improvement without significant difference between groups. Till the latest follow-up, TLIF was found to be superior to PLF in maintenance of disc height and avoidance of reduction loss as well. The ODI, NRS and SF-36 scores were significant improved after surgery and at last follow up, while demonstrating no significant difference between the two groups.Conclusion Both TLIF and PLF were effective in treating_Meyerding grade Ⅰ～Ⅱ lumbar spondylolisthesis, whereas TLIF was superior to PLF in maintenance of disc height and avoidance of reduction loss.