Biomechanical evaluation of methods of posterior stabilization of the spine and posterior lumbar interbody arthrodesis for lumbosacral isthmic spondylolisthesis. A calf-spine model

In order to evaluate biomechanically the efficacy of four types of posterior instrumentation for the stabilization of isthmic spondylolisthesis of the lumbosacral spine, mechanical non-destructive cyclic testing in axial compression, flexion, extension, and rotation was performed on six fresh lumbosacral spines from calves. Each segment contained four motion segments, including the lumbosacral junction. Isthmic spondylolisthesis was created by sectioning the pars interarticularis of the sixth lumbar vertebra and all posterior ligaments between the fifth and sixth lumbar levels. Eight constructs were tested sequentially: (1) the intact spine, (2) the destabilized spine, (3) the spine fixed with Harrington double-distraction rods, (4) the spine treated with transpedicular Cotrel-Dubousset instrumentation with a transverse approximating device, (5) the spine treated with Steffee transpedicular screws and plates, (6) the spine treated with posterior lumbar interbody arthrodesis, (7) the spine treated with Cotrel-Dubousset instrumentation and posterior lumbar interbody arthrodesis, and (8) the spine treated with Steffee instrumentation and posterior lumbar interbody arthrodesis. One motion segment was involved in each construct, except for the spine that was fixed with Harrington instrumentation, which involved three segments. Strain across the supraspinous and anterior longitudinal ligaments was measured with two extensometers that were attached at the spondylolisthetic level and at the intact motion segments adjacent to the fixed level. Harrington instrumentation was the least rigid construct under any type of loading except axial compression (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Spontaneous fusion of isthmic spondylolisthesis after discitis: a case report

This is the first case report of a child with isthmic spondylolisthesis and discitis who had spontaneous fusion develop at an unstable level with relief of symptoms after nonoperative treatment. Although the blood culture was negative, the 14-year-old boy with Grade III isthmic spondylolisthesis of L5 was diagnosed with discitis at the L5-S1 level, based on clinical findings, elevated C-reactive protein, plain radiographs, and magnetic resonance imaging scans. The patient was treated with antibiotics for 19 weeks and bed rest for 4 weeks followed by immobilization in a hip spica cast for 8 weeks and a thoracolumbosacral orthosis for an additional 12 weeks. The lumbar back pain improved and there was a decrease in C-reactive protein to the normal range 3 weeks after onset. Forty months from onset, the patient was free from lumbar back or leg pain and his clinical neurologic examination was normal. Plain radiographs showed spontaneous fusion between L5 and the sacrum. This suggests that nonoperative treatment is acceptable even if discitis occurs at an unstable level.     

Minimum 2-year analysis of sacropelvic fixation and L5-S1 fusion using S1 and iliac screws

STUDY DESIGN: An analysis of lumbosacral fusions for high-grade spondylolisthesis fusions with reduction and long fusions to the sacrum in ambulatory adults. OBJECTIVE: To assess the clinical and radiographic results of lumbosacral fusions using bilateral S1 and iliac screws. SUMMARY OF BACKGROUND DATA: S1 screws often fail with lumbosacral fusions, whereas L5-S1 pseudarthrosis is common in patients with deformity. MATERIALS AND METHODS: A total of 81 patients (38 revision, 43 primary) with minimum 2-year follow-up (average, 4.2 years; range, 2.0-7.1 years) underwent L5-S1 fusion using S1 and iliac screws (158 screws). Forty-nine of 81 constructs (61%) included an anterior load-sharing/fixation device. Group 1 included isthmic spondylolisthesis (n = 42), whereas Group 2 included long fusions (> or =3 levels) to the sacrum (n = 39). In Group 2, 15 patients (Group 2A) were fused from L1, L2, or L3 to the sacrum (3-5 levels, average 3.3 levels) and 24 patients (Group 2B) were fused from the thoracic spine to the sacrum (6-17 levels, average 11.5 levels). Twelve patients had pseudarthrosis at L5-S1. A patient questionnaire was completed. RESULTS: A total of 36 of the 38 revision patients had previous iliac crest harvesting, yet iliac screws were placed in 34 of 36 patients. Overall, 78 of 80 patients had iliac crest harvesting (one not attempted). None had loss of screw fixation or iliac crest fracture after harvesting. Four of the 81 patients (4.9%) had pseudarthrosis at L5-S1 after reconstruction. This included solid fusion in 10 of 12 patients presenting with L5-S1 pseudarthrosis. Fourteen percent of patients experienced some discomfort over the iliac screws; however, only one patient required screw removal. CONCLUSIONS: Bilateral iliac screws coupled with bilateral S1 screws provide excellent distal fixation for lumbosacral fusions with a high fusion rate (95.1%) in high-grade spondylolisthesis and long fusions to the sacrum. Previous iliac crest harvesting does not prevent ipsilateral screw placement (34 of 36 patients) or additional iliac harvesting (78 of 80 patients).     

Anterior spondylodesis for spondylolisthesis: Isthmic and degenerative types

Summary We studied the influence of instability of the spondylolisthesic segment upon anterior interbody fusion (AIF) rates. A one-level AIF of the lumbar spine by the modified extraperitoneal Bailey-Badgley fusion construct was performed in 26 patients with chronic or recurring acute low-back pain and/or other symptoms due to grades I and II spondylolisthesis. Sixteen were degenerative type, and 10 were isthmic type. Seventeen were female and 9, male. The average age was 41.2 years. The number of cases of spondylolisthesis at the level of L4–5 and L5-S1 as 18 and 8, respectively. In the 16 cases of degenerative type, 13 were grade I slip, and 3 were grade II slip, while in the 10 cases of isthmic type, 8 were grade I slip, and 2 were grade II slip. The average postoperative follow-up was 6 years (range 2–10 years). Solid fusion was obtained in 15 (93.8%) of the cases of degenerative spondylolisthesis and in 6 of the cases of isthmic type. Thus, the overall fusion rate was 80.7% (21 cases). However, some graft crumbling and redisplacement developed in 1 of the cases of degenerative type and 6 of the cases of isthmic type. Non-union developed in 4 (57.1%) of those 7 cases of graft crumbling (3 isthmic and 1 degenerative type). Fusion took 7 months on average (range 5–9 months). It is hypothesised that the isthmic-type spondylolisthesis has more instability than the degenerative one. Therefore, AIF in the case of degenerative spondylolisthesis is a useful procedure, while in the isthmic type it is not advisable as a routine procedure.     

Traumatic lumbosacral fracture dislocation: a case report and review of the literature

Lumbosacral dislocation is uncommon. We report a case of traumatic lumbosacral dislocation which occurred in a 33-year-old pedestrian traffic accident victim. The posterior impact produced lumbar injury with diffuse pain exacerbated at the lumbosacral junction. Ecchymotic diffusion involving the entire lumbar region fluctuated due to the presence of a subcutaneous hematoma. The neurological examination revealed incomplete L5 paraplegia. Standard x-rays revealed L5-S1 spondylolisthesis and fracture of the L5 spinous process as well as fractures of the L3, L4, and L5 transverse processes. Computed tomography disclosed biarticular L5-S1 fracture dislocation and a voluminous herniation of the L5-S1 disc. Emergency surgery was performed and revealed subaponeurotic detachment from T4 to S1 and bald iliac pyramids. After L5 laminectomy and extraction of the voluminous herniation of the L5-S1 disc, a short L5-S1 posteriolateral fusion was achieved using pedicular screws and two rods on either side as well as a posterolateral iliac autograft. The clinical course was satisfactory with nearly complete neurological recovery (persistent levator ani paresis). This clinical case and a review of the literature illustrate the pathogenic, clinical, radiological and therapeutic aspects of lumbosacral fracture dislocation.     

腰5椎体Ⅱ度以上峡部裂性滑脱的手术策略

目的探讨腰5椎体Ⅱ度以上峡部裂性滑脱的手术治疗策略。方法 2003年8月～2008年10月,应用经椎间孔腰椎间融合（transforaminal lumbar interbody fusion,TLIF）技术,以小关节突为中心椎管减压、椎间隙松解撑开复位、椎弓根钉棒系统补充复位固定、椎间隙打压植骨联合椎间融合器技术治疗腰5椎体Ⅱ度以上峡部裂性滑脱26例。结果经18～36个月（平均30个月）随访,滑脱椎体复位无丢失,椎间隙高度维持良好,下腰椎生理弧度恢复正常,椎弓根螺钉无断裂、松动,融合器无移位、沉降。25例获骨性融合。根据NaKai评分标准,优良率为84.6%。结论采用TLIF技术治疗腰5椎体Ⅱ度以上滑脱,神经根管减压是影响疗效的关键因素,滑脱椎体复位有利于神经根减压以及椎间融合率的提高,椎体间融合是维持长期疗效的基础。     

Transvertebral Transsacral strut grafting for high-grade isthmic spondylolisthesis L5-S1 with fibular allograft

STUDY DESIGN: A clinical retrospective study was conducted. OBJECTIVE: To evaluate the clinical and radiographic outcomes of 25 consecutive patients with symptomatic high-grade isthmic spondylolisthesis at L5-S1 treated by decompression and transvertebral, transsacral strut grafting with fibular allograft. SUMMARY OF BACKGROUND DATA: Symptomatic high-grade isthmic spondylolisthesis serves as a challenging clinical problem. Traditional treatment by in situ posterolateral arthrodesis has been associated with pseudarthrosis rates up to 50%. Even with successful posterolateral fusion, the graft is in an unfavorable biomechanical environment, owing to it being under tension, which can allow for progression of lumbosacral kyphosis (slip angle) and sagittal translation (slip). Open reduction of spondylolisthesis improves the biomechanical situation by allowing a trapezoidal interbody graft at L5-S1, but is associated with neurologic deficits in up to 30% of patients. The technique used in this particular study achieves the biomechanical goal of a structural interbody construct without the necessity of anatomically reducing the translational slip. The fibular strut grafts were placed through an anterior approach as part of an anterior/posterior procedure, or via a posterior approach as part of a posterior-only procedure. METHODS: A consecutive series of 25 symptomatic patients with high-grade isthmic spondylolisthesis at L5-S1 had an average age of 29.8 years. Six patients were 16 years or younger. Eight patients underwent a posterior-only approach with posterior transosseous fibular strut grafting across S1 into the L5 vertebral body combined with posterolateral arthrodesis L4-S1 using a pedicle screw-rod construct. Seventeen patients underwent a combined anterior/posterior approach with transosseous fibular allograft strut grafting at L5-S1 and L4-L5 interbody arthrodesis using a femoral ring allograft supplemented with L4-S1 posterior pedicle screw-rod instrumentation. No reduction attempts were performed, other than those occurring spontaneously by patient positioning and decompression. Patients were evaluated for clinical improvement and radiographically. Clinical outcomes were measured with the scoliosis research society outcome instrument. Radiographs were followed for arthrodesis, translation, and slip angle. Mean follow-up was 39 months (range, 30 to 71 mo). All patients preoperatively had a grade III to V slip using the Meyerding classification (mean 3.7). The slip angle averaged 37 degrees. RESULTS: The postoperative mean slip grade was 3.5 compared with 3.7 preoperatively (no significant difference). The mean slip angle improved to 27 degrees (8 to 40 degrees) postoperatively from 37 degrees (13 to 51 degrees) preoperatively (P<0.05). All patients went on to a stable arthrodesis, with no progression in slip or slip angle. There were no permanent neurologic deficits among any of the subjects, and all patients demonstrated improvement in their preoperative gait disturbance. Scoliosis research society functional outcome score showed 24/25 extremely satisfied or somewhat satisfied at latest follow-up. CONCLUSIONS: Treatment by this method showed improvement in lumbosacral kyphosis while avoiding the neurologic injury risk associated with open slip-reduction maneuvers. Despite no reduction in translational deformity, this technique offers excellent fusion results, good clinical outcomes, and prevents further sagittal translation and lumbosacral kyphosis progression.     

Sagittal plane configuration of the sacrum in spondylolisthesis

STUDY DESIGN: A radiographic study of the sagittal sacral deformity in spondylolisthesis. OBJECTIVES: To characterize and classify the pathoanatomy of sagittal sacral deformation in spondylolisthesis. SUMMARY OF BACKGROUND DATA: Spondylolisthesis has been extensively described and reviewed in the literature. Deformity of the entire sacrum in spondylolisthesis potentially could affect the natural history, treatment options, and outcome. The sagittal contour of the entire human sacrum has never been quantitatively studied in spondylolisthesis. METHODS: A literature search was performed and data was gathered retrospectively on patients with spondylolisthesis at the authors' institution. Cases of degenerative spondylolisthesis were excluded. Specifically those patients with L5-S1 spondylolisthesis were studied. The authors studied standing lateral radiographs and performed statistical analysis to understand morphologic relations. RESULTS: A broad range of global sacral kyphosis (37-188 degrees ) exists in spondylolisthesis. Increasing sacral kyphosis is significantly associated with increasing percent slip, sacral horizontal angle, Neuman's classification, lumbar lordosis, and lumbar index. A simple classification of the spectrum of sacral deformity in the sagittal plane is presented. CONCLUSION: The entire sacrum in spondylolisthesis can develop a significant kyphotic deformity in the sagittal plane, and this is associated with other abnormalities found in the lumbosacral spine. Sacral deformity is a significant factor in the assessment of the sagittal contour of the patient with L5-S1 spondylolisthesis.     

Progression of lumbosacral isthmic spondylolisthesis in adults

STUDY DESIGN: A retrospective clinical and radiographic review of adult patients with progressive isthmic lumbosacral spondylolisthesis. OBJECTIVES: To describe the clinical presentation of adult-onset progression of isthmic spondylolisthesis and to analyze its causes. SUMMARY OF BACKGROUND DATA: Until recently, progression of lumbosacral spondylolisthesis in adults was rarely reported. On the contrary, although slip progression before skeletal maturity has been widely recorded, its occurrence in adults has been doubted. Only sporadic case reports of adult slip progression and only brief notes on the subject in clinical studies describing other aspects of spondylolisthesis have been published. METHODS: Patients with isthmic lumbosacral spondylolisthesis who had serial radiographs of the lumbar spine on which slip progression during adult life was noted were evaluated. The amount of vertebral slip was calculated in millimeters from decubitus lateral spinal radiographs. The calculation was expressed as the percentage of slipped vertebral body length. RESULTS: From 1989 to 1995, 18 patients (9 women and 9 men), ages 32 to 55 years, with documented adult isthmic slip progression were identified at the Spinal Surgery Unit of the Hadassah University Hospital. All patients reported incapacitating low back pain, accompanied in most by significant sciatica. Documented slip progression ranged from 9% to 30% (average, 14.6%), and occurred during a period of 2 to 20 years (average duration, 6.8 years). Slip progression started after the third decade of life and coincided with marked disc degeneration at the olisthetic level. Slip progression associated with disc degeneration (i.e., intervertebral space narrowing and the formation of spondylophytes and vacuum phenomenon) brought about severe clinical symptomatology related to segmental instability and spinal stenosis. Of the 18 patients in this study, 14 were treated with surgery. All these patients except 1 underwent decompression, pedicle screw fixation, and bilateral lateral fusion. One patient underwent posterolateral fusion without instrumentation. Immediate postoperative complications were observed in three patients, including two superficial wound infections and one transient foot drop. Solid fusion was obtained in 11 of the 14 patients who underwent surgery. CONCLUSIONS: The concurrent occurrence of disc degeneration at the slip level and adult slip progression explains how an asymptomatic developmental lesion, present for at least two to three decades, may become symptomatic.     

Comparison of Functional Outcomes following Surgical Decompression and Posterolateral Instrumented Fusion in Single Level Low Grade Lumbar Degenerative versus Isthmic Spondylolisthesis

Background

The two most common types of surgically treated lumbar spondylolisthesis in adults include the degenerative and isthmic types. The aim of this study was to compare the functional outcomes of surgical decompression and posterolateral instrumented fusion in patients with lumbar degenerative and isthmic spondylolisthesis.

Methods

In this retrospective study, we reviewed the clinical outcomes in surgically treated patients with single level, low grade lumbar degenerative, and isthmic spondylolisthesis (groups A and B, respectively) from August 2007 to April 2011. We tried to compare paired settings with similar initial conditions. Group A included 52 patients with a mean age of 49.2 ± 6.1 years, and group B included 52 patients with a mean age of 47.3 ± 7.4 years. Minimum follow-up was 24 months. The surgical procedure comprised neural decompression and posterolateral instrumented fusion. Pain and disability were assessed by a visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. The Wilcoxon and Mann-Whitney U-tests were used to compare indices.

Results

The most common sites for degenerative and isthmic spondylolisthesis were at the L4-L5 (88.5%) and L5-S1 (84.6%) levels, respectively. Surgery in both groups significantly improved VAS and ODI scores. The efficacy of surgery based on subjective satisfaction rate and pain and disability improvement was similar in the degenerative and isthmic groups. Notable complications were also comparable in both groups.

Conclusions

Neural decompression and posterolateral instrumented fusion significantly improved pain and disability in patients with degenerative and isthmic spondylolisthesis. The efficacy of surgery for overall subjective satisfaction rate and pain and disability improvement was similar in both groups.     

Low lumbar burst fractures: a unique fracture mechanism sustained in our current overseas conflicts

Background contextThe most common location for burst fractures occurs at the thoracolumbar junction, where the stiff thoracic spine meets the more flexible lumbar spine. With our current military conflicts in Iraq and Afghanistan, we have seen a disproportionate number of low lumbar burst fractures.PurposeTo report our institutional experience in the management of low lumbar burst fractures.Study designRetrospective review.MethodsWe performed a retrospective review of medical records and radiographs for all patients treated at our institution with combat-related injuries and thoracolumbar fractures. We included all patients who had sustained a burst fracture from T12 to L5 and had at least 1-year clinical follow-up.ResultsThirty-two patients sustained burst fractures. Nineteen patients (59.4%) had low lumbar (L3–L5) burst fractures, and 12 patients (37.5%) had thoracolumbar junction (T12–L2) burst fractures as their primary injury. Additionally, seven patients sustained less severe burst fractures at an additional level. One patient sustained burst fractures at both upper and lower lumbar levels. Of the low lumbar fractures, 52.6% had evidence of neurologic injury, two of which were complete. Similarly, in the upper lumbar group, 58.2% sustained a neurologic injury, two of which were complete. Twenty-two patients underwent surgical intervention, complicated by infection in 18%. At most recent follow-up, all but one patient with presenting neurologic injury had persistent deficits.ConclusionLow lumbar burst fractures are the predominant combat-related spine injury in our current military conflicts. The rigidity offered by current body armor may effectively lower the transition zone that normally occurs at the thoracolumbar junction, thereby, transferring forces into the lower lumbar spine. Increased awareness of this fracture pattern is warranted by all surgeons because of unique clinical challenges associated with its treatment. Although the incidence is increased in the military population, other surgeons may be involved with long-term care of these patients on completion of their military service.     

Preoperative evaluation of adult isthmic spondylolisthesis with diskography

Fourteen consecutive patients with a diagnosis of isthmic spondylolisthesis (grade I and II) underwent provocative lumbar diskography (L2-S1) to evaluate the disk adjacent to the spondylolisthesis. Seven (50%) of 14 patients had concordant pain at the disk above the slip and 2 patients had no pain at the slip level. Surgical treatment included anteroposterior fusion of the slip level and any adjacent concordant levels. Clinical results included 3 excellent, 7 good, 2 fair, and 1 poor outcome. This data supports the hypothesis that the disk adjacent to an isthmic slip is predisposed to symptomatic degeneration in the adult patient with axial pain. It does not prove that a fusion is indicated or that clinical outcomes would be improved with this approach.     

Radiographic analysis of lumbar motion in relation to lumbosacral stability. Investigation of moderate and maximum motion

STUDY DESIGN: This in vivo study was performed to examine active lumbar motion without any support. OBJECTIVES: To establish the behavior of segmental flexibility according to the degree of whole lumbar motion and to clarify the correlation between bony characteristics of the lumbosacral junction and stability in the segment. SUMMARY OF BACKGROUND DATA: In previous studies, the full mobility of the lumbar segments has been investigated. The details of motion commonly seen with the activities of daily living have not been clarified. It has been reported that the iliolumbar ligaments have an influence on lumbosacral stability and that the relative thickness of the transverse process of L5 could indicate the functional strength of the iliolumbar ligaments. However, the effects of the iliolumbar ligaments on the lumbosacral range of motion have not been studied in vivo. METHODS: Ninety adults, aged 20-39 years, were requested to perform motion commonly associated with activities of daily living, defined as moderate motions of the lumbar spine. The subjects then were asked to perform maximal motion of the lumbar spine. The segmental ranges of motion, segmental flexion, and extension at every level of the lumbar spine were calculated by using functional radiographs. The correlation between the relative thickness of the transverse process of L5 and the motion seen at the lumbosacral junction was also determined. RESULTS: The greatest segmental range of motion was found at L2-L3 in moderate motion and at L4-L5 in maximal motion. It shifted gradually from the upper to lower lumbar levels with the increase in total lumbar motion. With an increase in lumbar spine motion, maximum segmental flexion shifted from L2-L3 to L3-L4, then to L4-L5. Segmental extension changed only at L5-S1, increasing with total lumbar spine motion. There was an inverse statistical correlation between lumbosacral motion and relative thickness of the L5 transverse process. CONCLUSIONS: The greatest segmental flexibility induced by the moderate lumbar motion, usually seen with the activities of daily living, occurred more in the upper segments of the lumbar spine, especially in flexion. Further, the iliolumbar ligaments regulate lumbosacral motion especially flexion.     

Reduction of high-grade isthmic and dysplastic spondylolisthesis in 5 adolescents

Treatment of high-grade isthmic and dysplastic spondylolisthesis in children and adolescents remains a challenge. Surgical treatment of spondylolisthesis has been recommended in adolescents with pain refractory to nonoperative modalities, slippage progression, or > 50% slippage on presentation. Controversy exists as to the optimal surgical approach for high-grade spondylolisthesis. In this report, we describe 5 cases of high-grade isthmic and dysplastic spondylolisthesis in adolescents and review the literature on surgical treatment for this entity. Operative records, charts, x-rays, and Scoliosis Research Society outcome questionnaires (SRS-22) were retrospectively evaluated for 5 consecutive patients diagnosed with and treated for high-grade spondylolisthesis. Each patient received treatment consisting of decompression, reduction, and circumferential fusion with transpedicular and segmental fixation from a posterior approach. Two patients had transient L5 nerve root deficit, which resolved within 3 months. Reduction benefits include a decrease in shear stresses (and resulting decreased rates of postoperative pseudarthrosis and slip progression), restoration of sagittal alignment and lumbosacral spine balance, and improvement in clinical deformity.     

Unilateral transforaminal posterior lumbar interbody fusion (TLIF): indications, technique, and 2-year results

A prospective analysis of consecutive cases of lumbar fusion using the unilateral transforaminal posterior lumbar interbody fusion (TLIF) technique with pedicle screw fixation. The objective of the study was to assess the clinical and radiographic outcome of TLIF and describe the technique and indications in the treatment of degenerative disease of the lumbar spine. Forty patients treated with TLIF for degenerative diseases of the lumbar spine were followed up for a minimum of 2.5 years (mean: 36 months; range: 30-42 months). Twenty-three patients had degenerative disc disease alone, 13 had associated isthmic or degenerative spondylolisthesis, and 4 had recurrent disc herniations at the L4-L5 level. Thirty-six (90%) had solid fusions radiographically at latest follow-up. Seventy-nine percent had excellent or good clinical outcomes. Our patients demonstrated high fusion rates and patient satisfaction.     

Geometry of the vertebral bodies and the intervertebral discs in lumbar segments adjacent to spondylolysis and spondylolisthesis: pilot study

The objective is to evaluate the geometric parameters of vertebral bodies and intervertebral discs in spinal segments adjacent to spondylolysis and spondylolisthesis. This pilot cross-sectional study was an ancillary project to the Framingham Heart Study. The presence of spondylolysis and spondylolisthesis as well as measurements of spinal geometry were identified on CT imaging of 188 individuals. Spinal geometry measurements included lordosis angle, wedging of each lumbar vertebra and intervertebral disc. Last measurements were used to calculate ΣB, the sum of the lumbar L1–L5 body wedge angles; and ΣD, the sum of the lumbar L1–L5 intervertebral disc angles. Using Wilcoxon–Mann–Whitney test we compared the geometric parameters between individuals with no pathology and ones with spondylolysis (with no listhesis) at L5 vertebra, ones with isthmic spondylolisthesis at L5–S1 level, and ones with degenerative spondylolisthesis at L5–S1 level. Spinal geometry in individuals with spondylolysis or listhesis at L5 shows three major patterns: In spondylolysis without listhesis, spinal morphology is similar to that of healthy individuals; In isthmic spondylolisthesis there is high lordosis angle, high L5 vertebral body wedging and very high L4–5 disc wedging; In degenerative spondylolisthesis, spinal morphology shows more lordotic wedging of the L5 vertebral body, and less lordotic wedging of intervertebral discs. In conclusion, there are unique geometrical features of the vertebrae and discs in spondylolysis or listhesis. These findings need to be reproduced in larger scale study.     

Profiles of the cervical, thoracic, and lumbosacral spine in children and adolescents with lumbosacral spondylolisthesis.

The sagittal and frontal profiles of the entire spine are poorly studied in lumbosacral spondylolisthesis. It was the purpose of this study to further investigate these profiles. Standing posterior-anterior and lateral radiographs in 24 children with lumbosacral spondylolisthesis were reviewed (18 isthmic, 6 congenital). Cervical lordosis, lumbar lordosis, thoracic kyphosis, sagittal vertebral axis, sacral inclination, slip magnitude, slip angle, and sagittal rotation were measured. Cobb magnitude, Risser sign, curve location, and direction were noted for those with scoliosis. Relationships between sagittal variables were explored (Pearson correlation). The average age of patients was 14.7 +/- 2.5 years, slip magnitude was 38 +/- 38%, slip angle was 5 +/- 31 degrees, sagittal rotation was -6 +/- 31 degrees, thoracic kyphosis was 29 +/- 16 degrees, cervical lordosis was -1 +/- 12 degrees, and lumbar lordosis was 62 +/- 22 degrees. Correlations were noted between thoracic kyphosis and sacral inclination, percent slip, slip angle, and sagittal rotation. Sacral inclination decreased as the slip increased. Scoliosis was present in 10 children, with an average curve of 19 +/- 6 degrees. Thoracic kyphosis was less in those with scoliosis (21 +/- 25 degrees versus 33 +/- 25 degrees, p = 0.033). In children with lumbosacral spondylolisthesis, the sacrum becomes more vertical as the slip worsens. As the sacrum becomes more vertical, the thoracic spine becomes more lordotic, which is likely an adaptive mechanism used by the body to maintain forward visual gaze.     

The long-term effect of posterolateral fusion in adult isthmic spondylolisthesis: a randomized controlled study.

BACKGROUND: Today there is some evidence-based medicine support for a positive short-term treatment effect of fusion in chronic low back pain in spondylolisthesis and in nonspecific degenerative lumbar spine disorders. The long-term effect is, however, unknown. PURPOSE: To determine the long-term outcome of lumbar fusion in adult isthmic spondylolisthesis. STUDY DESIGN: Prospective, randomized controlled study comparing a 1-year exercise program with instrumented and non-instrumented posterolateral fusion with average long-term follow-up of 9 years (range, 5-13). PATIENT SAMPLE: 111 patients aged 18 to 55 years with adult lumbar isthmic spondylolisthesis at L5 or L4 level of all degrees, and at least 1-year's duration of severe lumbar pain with or without sciatica. OUTCOME MEASURES: Pain and functional disability was quantified by pain (VAS), the Disability Rating Index (DRI), the Oswestry Disability Index (ODI) work status, and global assessment of outcome by the patient into much better, better, unchanged or worse. Quality of life was assessed by the SF-36. METHODS: The patients were randomly allocated to treatment with 1) a 1-year exercise program (n=34), 2) posterolateral fusion without pedicle screw instrumentation (n=37), or 3) posterolateral fusion with pedicle screw instrumentation (n=40). Long-term follow-up was obtained in 101 (91%) patients. Nine patients in the exercise group were eventually operated on. RESULTS: Longitudinal analysis: At long-term follow-up pain and functional disability were significantly better than before treatment in both surgical groups. No significant differences were observed between instrumented and non-instrumented patients in any variable studied. In the exercise group the pain was significantly reduced but not the functional disability. Compared with the 2-year follow-up a significant increase in functional disability was observed, as measured by the DRI, but not the ODI, in the surgical group at long term. In the exercise group no significant changes were observed between the 2-year and the long-term follow-up. Cross-sectional analysis: Between the surgical and conservative group no significant differences were observed in any outcome measurement at long-term follow-up except for global assessment, which was significantly better for surgical patients. Of surgical patients 76% classified the overall outcome as much better or better compared with 50% of conservatively treated patients (p=0.015). Quality of life as estimated by the SF-36 at long term was not different between treatment groups in any of the eight domains studied but was considerably lower than for the normal population. CONCLUSIONS: Posterolateral fusion in adult lumbar isthmic spondylolisthesis results ina modestly improved long-term outcome compared with a 1-year exercise program. Although the results show that some of the previously reported short-term improvement is lost at long term, patients with fusion still classify their global outcome as clearly better than conservatively treated patients. Furthermore, because the long-term outcome of the patients conservatively treated most likely reflects the natural course, one can also conclude that no considerable spontaneous improvement should be expected over time in adult patients with symptomatic isthmic spondylolisthesis. Substantial pain, functional disability and a reduced quality of life will in most patients most likely remain unaltered over many years.     

Transverse plane pelvic rotation in adolescent idiopathic scoliosis: primary or compensatory?

Several studies have suggested that the pelvis is involved in the etiology or pathogenesis of adolescent idiopathic scoliosis (AIS). The purpose of this retrospective, cross-sectional radiographic study is to identify any correlation between the transverse plane rotational position of the pelvis in stance and operative-size idiopathic or congenital scoliosis deformities, using Scheuermann’s kyphosis and isthmic spondylolisthesis patients for comparison. The hypothesis tested was that the direction of transverse pelvic rotation is the same as that for a thoracic scoliosis. As a group, AIS patients had a significant transverse plane pelvic rotation in the same direction as the thoracic curve. When subdivided into the six Lenke curve patterns, this was true for the groups with a major thoracic curve: thoracic (1), double thoracic (2) and double curve patterns (3). It was not true for patterns with a major thoracolumbar/lumbar curve: single thoracolumbar/lumbar (5) and double thoracic-thoracolumbar/lumbar (6). Nor was it true for triple (4) curves. The Lenke 1 and 2 major thoracic curves without compensatory thoracolumbar/lumbar curves did not have the predicted pelvic rotation. All congenital scoliosis patients studied had main thoracic curves and significant transverse plane pelvic rotation in the same direction as the thoracic curve. There was no transverse plane pelvic rotation in the Scheuermann’s kyphosis or isthmic spondylolisthesis patients. We interpret these findings as consistent with a compensatory rotation of the pelvis in the same direction as the main thoracic curve in most patients with a compensatory thoracolumbar/lumbar curve as well as in patients with main thoracic congenital scoliosis.