Sacral dome resection and single-stage posterior reduction in the treatment of high-grade high dysplastic spondylolisthesis in adolescents and young adults

Minimally invasive transforaminal interbody fusion for high-grade spondylolisthesis: a retrospective study analysis of a tailor-made solution

STUDY DESIGN

Retrospective study.

PURPOSE

We investigated cantilever reduction and fusion technique in high-grade spondylolisthesis (HGS) with minimally invasive surgery-transforaminal interbody fusion (MIS-TLIF).

OVERVIEW OF LITERATURE

Most publications that describe minimally invasive surgeries for HGS, especially grade 4 or 5 listhesis, utilized a combined anterior and posterior approach. To the best of our knowledge, a detailed report that provides specific technical nuances for optimal use of a posterior-only approach utilizing MIS-TLIF is greatly lacking.

METHODS

This study included 36 patients with HGS in whom reduction, posterior instrumentation, and fusion were achieved with MIS- TLIF. They were evaluated for lower back pain and radicular pain, scaled by Visual Analog Scale (VAS) score. Erect radiographs were performed to calculate slip angle (SA) and sacropelvic and spinopelvic parameters preoperatively, postoperatively, and at each follow-up until 4 years.

RESULTS

This study identified 30 patients with grade III HGS and six patients with grade IV/V HGS. Spinopelvic parameters were unbalanced in 13 patients. Complete reduction was achieved in 24 patients, with end-stage reduction of grade I with adequate spinopelvic balance achieved in 12 patients. Intraoperative neuromonitoring demonstrated no loss of signals throughout the procedure in any of the patients. Excellent functional outcome was achieved with back pain as well as leg pain VAS score improvements postoperatively in all patients. No implant-related complications or pseudoarthrosis incidences were reported at long-term follow-up at 4 years.

CONCLUSIONS

MIS-TLIF for HGS is a specific solution for a complex pathology, enabling one to achieve an excellent clinical as well as radiological outcome.

An Acta Orthopaedica educational article: Treatment of pediatric spondylolysis and spondylolisthesis

Spondylolysis is defined as a defect or elongation in the pars interarticularis of the lumbar spine, either unilateral or bilateral. Growing children with bilateral spondylolysis may develop spondylolisthesis, i.e., forward slipping of the affected vertebra. The etiology of spondylolysis is regarded as a stress fracture due to repetitive loading associated with a genetic predisposition. Lumbar magnetic resonance imaging (MRI) shows an increased signal intensity before an actual fracture line develops. In low grade spondylolisthesis, two-thirds of children with acute pediatric spondylolysis will undergo bony union with early activity restriction. Health-related quality of life is improved in patients achieving bony union as compared with patients having non-union, of which one-fourth will additionally develop spondylolisthesis. In patients with high-grade spondylolisthesis, defined as a more than 50% forward slippage of the affected vertebra, spinal fusion is recommended to prevent further progression.

Restoration of Spinopelvic Alignment After Reduction of High-grade Spondylolisthesis: Myth or Reality? A Systematic Review of the Literature and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis of literature.

OBJECTIVE

The aim of the presented study is to assess whether the reduction of high-grade spondylolisthesis (HGS) through the correction of lumbosacral kyphosis leads to a decrease in the sagittal spinopelvic compensatory mechanisms.

SUMMARY OF BACKGROUND DATA

HGS is as an anterior translation of a vertebra, >50%. It is also characterized by a kyphotic deformity of the affected level. This combination of translation and kyphosis leads to compensatory mechanisms on the sagittal plane [pelvic retroversion, increased lumbar lordosis (LL), reduction in thoracic kyphosis (TK)].

METHODS

A systematic search of electronic databases was conducted. Inclusion criteria were diagnosis of HGS (Meyerding >II, Slip% >50%), partial or complete reduction surgery (with a significant decrease in Slip%), and report of spinopelvic parameters (pelvic incidence, pelvic tilt, or sacral slope). Clinical and radiographic outcomes were extracted and summarized. Meta-analyses were performed to estimate the differences between preoperative and postoperative spinopelvic alignment measures. P <0.05 was considered significant.

RESULTS

Eighteen studies were included. PT showed a statistically significant decrease of -2.1217 (95% CI: -3.4803 to -0.7630), while SS showed a significant increase of 4.8349 (95% CI: 2.7462-6.9236). Conversely, both LL and TK showed nonsignificant changes, -4.7043 (95% CI: -10.4535 to 1.0449) and 6.3881 (95% CI: -0.8344 to 13.6106), respectively. VAS significantly decreased by -3.1950 (95% CI: -4.9462 to -1.4439).

CONCLUSIONS

The meta-analysis showed mild, yet statistically significant, decrease of PT and an increase in SS after HGS reduction. Conversely, nonstatically significant decrease in LL and an increase in TK occurred. The clinical significance of these results remains questionable.

LEVEL OF EVIDENCE

Level IV.

Evaluation of the effectiveness of the femoro-sacral posterior angle system for measuring spino-pelvic morphology in high-dysplastic developmental spondylolisthesis

OBJECTIVE

The Femoro-Sacral Posterior Angle (FSPA) system and the pelvic incidence (PI) system are utilized for measuring sagittal spino-pelvic morphology in patients with high-dysplastic developmental spondylolisthesis (HDDS). This study aimed to analyze the accuracy and stability of these two systems.

METHODS

A retrospective analysis was conducted on 45 patients diagnosed with HDDS who underwent surgical treatment at our hospital (HDDS group), along with 45 patients without spondylolisthesis (normal group). Three orthopedic surgeons utilized the FSPA and PI systems to measure various parameters, including FSPA, pelvic angle(PA), sacral incidence (SI), PI, pelvic tilt (PT), and sacral slope (SS), respectively. The intraclass correlation coefficient (ICC) was employed to assess the inter-observer consistency of measurements.

RESULTS

There was significant differences in all the parameters between the normal and HDDS groups (p < 0.05), except for SS (p = 0.508). Specifically, SI was lower in HDDS group than in the normal group (23.0 ± 13.4 vs. 38.6 ± 7.1), whereas SS was higher (35.3 ± 15.7 vs. 33.6 ± 7.4). Within HDDS group, there was no statistically significant difference in PI (p = 0.159), SS (p = 0.319), and FSPA (p = 0.173) between pre- and post-surgery measurements. The ICC results indicated superior reliability for the FSPA system (0.842-0.885) compared to the PI system (0.682-0.720) within the HDDS group.

CONCLUSION

Compared with the PI system, the FSPA system demonstrated higher accuracy in evaluating spino-pelvic morphology in HDDS patients. Moreover, it exhibited higher ICC values, indicating higher inter-observer reliability, thus serving as an effective method for assessing spino-pelvic morphology in HDDS patients.

Modified S1 Pedicle Subtraction Osteotomy

STUDY DESIGN

Surgical technique video.

OBJECTIVE

To report a surgical technique to revise patients with previous fusions at L4-S1 leading to an iatrogenic flat back and sagittal imbalance using L5-S1 transforaminal interbody fusion combined with a small S1 corner osteotomy.

BACKGROUND

This is a case of a woman (51 y old) with a history of multiple lumbar surgeries, severe back pain, sagittal imbalance, and loss of lordosis.

METHODS

We describe a feasible revision technique in a complex patient with the goal of attaining optimal distribution of lumbar lordosis and sagittal balance through a modified S1 pedicle subtraction osteotomy, and the use of an interbody cage to enhance the fusion rate and facilitate closure of the 3-column osteotomy.

RESULTS

The preoperative patient lordosis angle of 31 degrees at L1-L4 and 16 degrees at L4-S1 became 12 degrees at L1-L4 and 44 degrees at L4-S1 postoperatively.

CONCLUSION

The combination of L5-S1 transforaminal interbody fusion and S1 corner osteotomy is a feasible technique for the restoration of lumbar lordosis in patients with previous fusion and consequent loss of lordosis.

[Surgical treatment of high-grade spondylolisthesis]

OBJECTIVE

Establishment of a physiological profile of the spine via reduction of the kyphotic slipped vertebra in the transverse and sagittal planes. Achieving solid fusion. Improvement of preoperative pain symptoms and prevention or elimination of neurological deficits.

INDICATIONS

High-grade spondylolisthesis (Meyerding grade 3 and 4) as well as spondyloptosis after conservative treatment and corresponding symptoms. Serious neurological deficits, hip-lumbar extensor stiffness, are emergency indications.

CONTRAINDICATIONS (CI)

Individual risk assessment must be made. Absolute CI are infections with the exception of serious neurological deficits. Multiple abdominal operations or interventions on the large vessels can be a relative contraindication for ventral intervention.

SURGICAL TECHNIQUE

For spondylolistheses of grade 3 according to Meyerding, we recommend a one-stage dorso-ventro-dorsal procedure with radicular decompression, correction and fusion in the index segment. From grade 4 according to Meyerding, reduction of the fifth lumbar vertebral body in the index segment L5/S1 is preceded by resection of the sacral dome. In cases of spondyloptosis, a two-stage procedure is often indicated. In this case, a screw-rod system spanning the index segment is implanted in the first step, which is used to distract the index segment for several days. Ventrodorsal reduction is performed in the second step.

POSTOPERATIVE MANAGEMENT

Axis-appropriate full mobilization from postoperative day 1. We recommend a light diet until the first defecation. Dorsal suture removal after 12 days if the wound is dry and free of irritation. Lifting and carrying heavy loads and also competitive or contact sports should be avoided for 12 weeks.

RESULTS

From January 2000 to December 2020, a total of 43 patients with high-grade spondylolisthesis were treated in our clinic in the manner described. The Numeric Rating Scale (NRS) and the Oswestry Disability Index (ODI) improved significantly during the observation period of 3 months and 1 year. The 1‑year radiological data in 28 of the 36 patients showed complete reduction of the slipped vertebra, in 6 grade 1, and in 2 patients grade 2 according to Meyerding. Also, the kyphosis of the index vertebra was significantly corrected from a mean of 15° (0-52°) preoperatively to a lordotic profile of a mean of 4° (0-11°). No complications requiring revision were observed. One patient with preoperative cauda equina syndrome was left with right radicular sensorimotor S1 syndrome.

Management of low back pain accompanying sagittal plane pathologies in children: Spondylolysis/spondylolisthesis and Scheuermann's disease

Background

Low back pain in childhood was underappreciated for a long time, but recent studies report higher prevalences, up to 70%. Two of the common causes are spondylolyis/spondylolisthesis and Scheuermann's disease. These disorders are relevant in a way they both cause significant back pain, and may disrupt the sagittal spinal balance.

Purpose

To present the current evidence on the diagnosis, natural history and treatment of these disorders with a special focus on sagittal spinal alignment.

Methods

This study is conducted as a literature review.

Results and Conclusions

Spondylolysis and low-grade spondylolisthesis have a benign course and are typically treated conservatively. When pars repair is indicated, pedicle screw-based techniques achieve more than 90% fusion with acceptable complication rates. High-grade spondylolisthesis, however, is frequently progressive. Surgical treatment involves fusion, which can be done in situ or after reduction. Reduction is useful for "unbalanced" patients to acquire sagittal spinopelvic balance, and it is important to distinguish these patients. Despite lowering the risk for pseudoarthrosis, reduction brings a risk for neurologic complications. With re-operation rates as high as 40%, these patients definitely require careful preoperative planning. Scheuermann's disease generally causes back pain in addition to cosmetic discomfort during adolescence. If the kyphosis is lower than 60°, symptoms typically resolve into adulthood with conservative measures only. However, it must be kept in mind that these patients may experience problems with physical performance and have a lower quality of life even when the problem seems to have "resolved". Severe kyphosis and intractable back pain are the most frequently referred surgical indications, and surgery typically involves fusion. Proper utilization of osteotomies and proper selection of the upper and lower fusion levels are of utmost importance to prevent complications in these patients.

Management of High-Grade Dysplastic Spondylolisthesis

The Meyerding classification grades the degree of slippage in the sagittal plane on lateral standing neutral imaging: 0% to 25% Grade I, 25% to 50% Grade II, 50% to 75% Grade III, 75% to 100% Grade IV, and greater than 100% Grade V (Spondyloptosis). Grades I and II are considered low-grade and Grades III-V are considered high-grade. There are several etiologies of spondylolisthesis. A classification system of the most common causes: Type I - Dysplastic, Type II - Isthmic (including subtypes: A - Lytic, B - Elongation, and C - Acute fracture), Type III - Degenerative, Type IV - Traumatic, Type V - Pathologic, and Type VI - Iatrogenic. Dysplastic spondylolisthesis is a type of spondylolisthesis that occurs at L5-S1 when dysplastic lumbosacral anatomy is present, and is associated with high-grade slip and spina bifida occulta.

Irreducible L5/S1 Spondyloptosis in Over 20 Years After Neglected Trauma Treated with Modified Grob's Technique - Case Report

Introduction

Spondyloptosis, characterized by complete slippage of the upper vertebral body relative to the lower vertebral body, is an exceedingly rare condition. Typically, it occurs as a result of a high-energy injury and is promptly managed. It is uncommon for a patient to present to a spinal surgery unit several decades after the initial incident.

Case Report

In this case report, we describe the case of a 62-year-old man who experienced a lumbosacral injury from a fall twenty years prior to seeking treatment. The patient had multiple comorbidities, including obesity and internal medicine conditions. He presented with severe back pain radiating to the lower extremities, accompanied by significant neurogenic chroma and lower extremity weakness. Imaging studies revealed spondyloptosis at the L5/S1 level, along with bony fusion and spinal canal stenosis at the L3/L4 level.

Conclusion

The patient underwent surgical intervention using Grob's direct pediculo-body fixation technique. The postoperative period was uneventful, and over the course of one year of follow-up, the patient experienced a resolution of symptoms and significant improvement in functional capacity.

'Higher the grade-smaller the pedicle': a study of pedicle dimensional variations in 100 cases of high grade lytic spondylolisthesis

PURPOSE

To measure the pedicle dimensions in high grade lytic spondylolisthesis (HGL) and to classify them, which helps the spine surgeon in proper selection of pedicle screws.

METHODS

A study of CT scans in 100 consecutive patients between Jan 2017 and April 2021 diagnosed as single-level HGL on standing radiographs. Pedicle height (PH), Pedicle width (PW), Differential pedicle height (DPH), Screw length (SL) and Transverse pedicle angle (TPA) were measured and analyzed. PH and PW were classified into four grades as-grade A less than 5.0 mm, grade B between 5.0 and 6.0 mm, grade C between 6.0 and 7.0 mm, and grade D above 7.0 mm.

RESULTS

5 males and 95 females with mean age of 49.1 years. PH in 44% lytic vertebra were grade A, B (less than 6 mm) and the rest 56% had grade C, D (greater than 6 mm). PH averaged 6.6 mm in grade 3 HGL, 5.61 mm in grade 4 HGL. Change in PW, SL and TPA was not statistically significant with regards to grade or level of listhesis. A total of 37 cases were noted to have DPH (25 cases had a difference < 2 mm and 12 had a difference > 2 mm).

CONCLUSION

44% of the PH in lytic vertebra was grade A and B (less than 6 mm) that stresses the importance of pre-op CT assessment and planning the appropriate screw dimensions. Change in PH was statistically significant with regards to the grade of listhesis (P-value < 0.01). Differential pedicle height also need to be looked for.

Posterior lumbar interbody fusion for dysplastic lumbar spondylolisthesis with high-grade slippage in two adolescent siblings: two case reports

BACKGROUND

Lumbar spondylolisthesis is reported to present with a familiar pattern, with the dysplastic type of spondylolysis being minor but more hereditary than the isthmic type. Siblings presenting during adolescence with neurological symptoms owing to high-grade dysplastic-type spondylolisthesis are rare.

CASE PRESENTATION

The older brother suffered from left leg pain and numbness and dysesthesia of the right posterior thigh and calf and could not walk without a crutch at the age of 15 years. He had canal stenosis with disc bulging and dysplastic bilateral facet joint at L5/S1. The L5 vertebral body was slipped anterior downward to S1, with a round-shaped S1 cranial endplate. We diagnosed dysplastic-type spondylolisthesis and performed posterior lumbar interbody fusion at L5/S with mild reduction and sublaminar wiring at L4/5. The younger brother had no neurological symptoms at age 14 years but suffered from bilateral lower leg numbness at age 18 years. He had canal stenosis with disc bulging at L4/5 and L5/S1 and dysplastic bilateral facet joint at L5/S1 with right pars defect. The L5 vertebral body was vertically displaced anterior to the S1 vertebral body, with an S1 round-shaped cranial endplate. We diagnosed dysplastic-type spondylolisthesis, and posterior lumbar interbody fusion at L4/5 and L5/S with reduction was performed. Their neurological symptoms of the lower legs disappeared, and interbody bone fusion was obtained.

CONCLUSIONS

The surgical technique for high-grade dysplastic spondylolisthesis remains controversial in terms of in situ fusion versus reduction. We recommend that surgery be performed promptly at the end of bone maturation because neurological symptoms often appear at the end of bone maturation. Because high-grade slips are rare but siblings may be present, the sibling should also be screened when dysplastic spondylolisthesis is detected.

Sacral Pedicle Subtraction Osteotomy for Treatment of High-Grade Spondylolisthesis: A Technical Note and Review of the Literature

BACKGROUND

Lumbosacral deformities are caused by high-grade spondylolisthesis, fractures, iatrogenic flat back, and other etiologies. The S1 pedicle subtraction osteotomy (PSO) can facilitate reduction of spondylolisthesis and lower the pelvic incidence. There are limited reports on the indications and outcomes of this technique.

OBJECTIVE

To present a technical description and literature review of the S1 PSO with video summary.

METHODS

This was a retrospective review of a single case to highlight the use of S1 PSO for the treatment of high-grade spondylolisthesis. A literature review was performed in accordance with STROBE guidelines.

RESULTS

A 47-year-old woman presented with back and right leg pain related to grade 4 spondylolisthesis at L5-S1 with sagittal imbalance and lumbosacral kyphosis. She was taken for an L2-pelvis instrumented fusion with S1 PSO. Three days later, she was taken for an L4-5 and L5-S1 anterior lumbar interbody fusion with the L5-S1 segmental plate. Her postoperative course was notable for right foot drop that resolved in 6 weeks. Postoperative x-rays showed successful reduction of spondylolisthesis with normal alignment and sagittal balance. Based on 6 studies involving 22 true sacral PSOs in the literature, the procedure carries a 27% risk of neurological deficit, typically in the form of L5 palsy.

CONCLUSION

The S1 PSO is a technically challenging operation that has a unique role in the treatment of high-grade spondylolisthesis. It carries a significant risk of L5 palsy and should be reserved for surgeons with experience performing complex 3-column osteotomies.

Vertebral Slip Morphology in Dysplastic Spondylolisthesis as a Criterion for the Choice of the L5/S1 Support (ALIF, PLIF, Fibular Graft) in Surgical Treatment

Dysplastic spondylolisthesis is a severe pathological condition, based on dysplastic changes in the lumbosacral part of the spine, that causes the asymmetry of the lumbosacral junction. The appropriate therapeutic algorithm remains controversial. As the gold standard, the surgical reposition of the slipped vertebra and 360° fusion of the affected spinal segment is preferred. Thirty-two patients were operated on between the years 2005 and 2018. Different techniques of 360° fusion, based on the severity of the displacement of the affected vertebral segment, were used. Herein, the advantages and disadvantages of different techniques of interbody fusion are discussed. The slippage and retention after reduction in the vertebrae are evaluated prior to the operation, postoperatively, one year after the surgery, and during follow-up, which was 7 years on average (minimum 2 years for a follow-up). Complications associated with the surgery are evaluated, in addition to the operation time, blood loss, spinopelvic parameters, and patient satisfaction with the surgery. All surgical techniques improved the slippage compared to preoperative conditions. The retention of the reposition was not changed significantly in postoperative controls. The incidence of neurological complications reached 12.5%. Surgical treatment is the only treatment option that successfully addressed the pathological principle of dysplastic spondylolisthesis. All of the surgical methods used led to restoring the symmetry of the lumbar spine, and to the improvement in both radiological parameters and the alleviation of subjective difficulties. The aim of this article is to summarize surgical methods in patients having dysplastic spondylolisthesis with a slip of more than 25%, who were operated on, and to determine the optimal treatment algorithm according to the severity of the slip.

Direct reduction of high-grade lumbosacral spondylolisthesis with anterior cantilever technique - surgical technique note and preliminary results

Backgrounds

Surgical reduction for high-grade spondylolisthesis is beneficial for restoring sagittal balance and improving the biomechanical environment for arthrodesis. Compared to posterior total laminectomy and long instrumentation, anterior lumbar inter-body fusion (ALIF) is less invasive and has the biomechanical advantage of restoring the original disk height and increasing lumbar lordosis, thus improving sagittal balance. However, the application of ALIF is still limited in treating low-grade spondylolisthesis. In this study, we developed a new technique termed anterior cantilever procedure to directly reduce the slippage of high-grade lumbosacral spondylolisthesis. The purpose of our study was to investigate the surgical outcomes of the anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation in high-grade spondylolisthesis.

Methods

All patients with high-grade spondylolisthesis who underwent anterior cantilever procedure followed by anterior lumbar inter-body fusion (ALIF) and posterior mono-segment instrumented fixation between November 2006 and July 2017 were enrolled in our study. The slip percentage, Dubousset’s lumbosacral angle, pelvic tilt, sacral slope, pelvic incidence, and sagittal alignment were measured pre-operatively and postoperatively at the last follow-up. Surgery time, blood loss, complications, and hospital stay were also collected and analysed.

Results

A total of 11 consecutive patients with high-grade spondylolisthesis patients were included and analysed. All of the high-grade spondylolisthesis in our series occurred at the L5-S1 level. The median age was 37 years, and the median follow-up duration was 36 months. The average slip reduction was 30% (60 to 30%, P < 0.01), and the average correction of Dubousset’s lumbosacral angle was 13.8° (84.1° to 97.9°, P < 0.01). The median intra-operative blood loss was 300 mL. All patients attained improved sagittal balance after the operation and achieved solid fusion within 9 months after surgery. No incidences of implant failure, permanent neurological deficit, or pseudarthrosis were recorded at the last follow-up.

Conclusions

Anterior cantilever procedure followed by ALIF and posterior mono-segment instrumented fixation is a valid procedure for treating high-grade spondylolisthesis. It achieved a high fusion rate, partially reduced slippage, and significantly improved lumbosacral angle, while minimizing common complications, such as pseudarthrosis, nerve traction injury, excessive soft tissue dissection, and blood loss in posterior reduction procedures. However, posterior instrumentation is still required to the structural stability in the ALIF procedure.

Level of evidence

IV

Curve Characteristics and Response of Sciatic and Olisthesis Scoliosis Following L5/S1 Transforaminal Lumbar Interbody Fusion in Adolescent Lumbar Spondylolisthesis

BACKGROUND

Lumbosacral spondylolisthesis-induced scoliosis is a rare clinical entity. Sagittal reconstruction and the coronal curve evolution after surgery for spondylolisthesis have not been investigated in depth.

OBJECTIVE

To compare the curve characteristics between sciatic scoliosis and olisthetic scoliosis and to further investigate the effects of lumbosacral transforaminal lumbar interbody fusion (TLIF) on scoliosis evolution.

METHODS

Adolescents with sciatic scoliosis group (SS group) or olisthetic scoliosis group (OS group) who underwent L5/S1 TLIF from 2010 to 2017 and were followed up for at least 2 yr were retrospectively reviewed. Radiographic parameters and patient-reported outcomes were evaluated.

RESULTS

There were 20 patients in the SS group (M/F: 8/12; age: 15.6 ± 2.2 yr) and 16 in the OS group (M/F: 6/10; age: 16.8 ± 2.5 yr). Both groups had similar preoperative Cobb angles, but more patients with coronal imbalance were observed in the SS group. Moreover, the OS group showed significantly larger L5 tilt and rotation. After surgery, the slip reduction rate of the SS group and OS group were 76.1% ± 12.4% and 79.4% ± 9.6%, respectively. Scoliosis resolution was observed in all patients in the SS group but only in 9 patients (56.2%) in the OS group. Patients with failed scoliosis resolution in the OS group were older and had a larger Cobb angle and L5 rotation compared with those with successful scoliosis resolution.

CONCLUSION

Lumbosacral TLIF can achieve satisfactory slip reduction and scoliosis resolution. Sciatic scoliosis often presents with coronal imbalance but also a preferable curve prognosis. A large Cobb angle and L5 rotation may hinder the resolution of olisthetic scoliosis.

The Joe-Lin Operative Classification System for Pediatric Lumbosacral Spondylolysis and Spondylolisthesis

OBJECTIVE

To propose and validate a novel and comprehensive classification of lumbosacral spondylolysis and spondylolisthesis in the pediatric population according to surgical managements.

METHODS

Cases of pediatric lumbosacral (L5/S1 level) spondylolysis and spondylolisthesis were reviewed. Lumbar Japanese Orthopedics Association score, health-related quality of life, spondylolisthesis, lumbosacral disc degeneration, and dysplastic features were included for evaluation of outcomes after surgery. We also conducted a reliability study to assess the classification.

RESULTS

A classification containing 4 types and a tentative treatment algorithm were proposed: type 1, direct pars repair without segmented fusion, for which the pedicle screw-U rod system is suitable; type 2, simple L5-S1 fusion; type 3, simple L4-S1 fusion; and type 4, simple L5-S2 fusion. All types of spondylolisthesis were suggested to achieve complete reduction and decompression. A total of 162 patients were included and we also reviewed the outcomes of patients in each type. All patients achieved satisfied outcomes. The reliability study showed that the average interobserver agreement was 89.5% (range, 85.2%-92.6%), with κ value of 0.862 (range, 0.802-0.901). Intraobserver agreement ranged from 88.9% to 92.6%, with an average κ value of 0.868 (range, 0.835-0.901).

CONCLUSIONS

In our study, we proposed and validated a novel comprehensive classification of pediatric lumbosacral spondylolysis and spondylolisthesis. The pedicle screw-U rod system provided more benefits in the treatment of simple lumbosacral spondylolysis, and fusion from L5 to S2 combined with S2 screw would also benefit patients with high-degree spondylolisthesis.

The Use of Sacral Osteotomy in the Correction of Spinal Deformity: Technical Report and Systematic Review of the Literature

BACKGROUND

Flat back deformity is a disabling adverse outcome following instrumented lumbar fusion. As patients are often fused in this non-physiologic alignment, correction is complex and has conventionally required fracture of the preexisting fusion mass. Sacral osteotomy may be one effective means of correcting the positive sagittal balance in these patients. Here we report a case of flat back deformity corrected using a 3-column sacral osteotomy, and systematically review the available literature on the effectiveness of 3-column sacral osteotomy for correcting flat back deformity.

METHODS

A systematic review was performed using the results of a search of the PubMed, EMBASE, Web of Science, and Cochrane databases according to PRISMA guidelines. We also include our patient as an example of the technique.

RESULTS

Eight studies-all case reports or small case series-were identified describing 37 patients, including our case example. The variety of techniques was too heterogeneous for meta-analysis, but all studies reported good correction of sagittal deformity. Transient L5 palsy was the most common side effect of this technique, being reported in 21 patients (56.8%) across all studies.

CONCLUSIONS

Sacral osteotomy is potentially an effective means of correcting positive sagittal balance in patients with flat back deformity secondary to high pelvic incidence.

High-Grade Lumbar Spondylolisthesis

Most high-grade spondylolistheses are resultant from isthmic spondylolisthesis, as complete discontinuity of the pars is typically necessary to allow for this degree of anterior vertebral translation, although can occur less commonly in other scenarios. Higher-grade slips can affect the global sagittal balance of the patient and often result in altered gait patterns and compensatory posturing. Management usually entails surgical decompression and fusion with instrumentation. The addition of anterior column support carries many advantages, including greater surface area for fusion, dynamic compression load sharing at the lumbosacral junction, and a powerful adjunct for deformity correction.

Surgical Treatment of Developmental Spondylolisthesis: Contemporary Series With a Two-Surgeon Team

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To report operative outcomes of contemporary surgical treatment of spondylolisthesis in the pediatric population.

SUMMARY OF BACKGROUND DATA

Surgical treatment of developmental spondylolisthesis is controversial, with limited data on complication and reoperation rates.

METHODS

A retrospective study followed pediatric patients with either L5-S1 high-grade spondylolisthesis (HGS) or L5-S1 symptomatic low-grade spondylolisthesis (LGS) for a minimum of two years. All patients underwent a contemporary, single-stage decompression, partial reduction, and posterior instrumented fusion (DRPF) or in situ stabilization by a combined orthopedic and neurosurgeon team at a single institution during 2005-2015. Clinical examination and radiographic data were collected preoperatively and at discharge, 1 year, 2 years, and terminal visit (defined as the last follow-up at >2 years).

RESULTS

Thirty-four patients (79% HGS), mean (±standard deviation) age at surgery 13.5 (±3.3) years, were followed for 4.8 (±2.3) years. The patients who underwent DRPF (n = 26) had mean lumbosacral angle increase from 79.8° (±20.8) to 92.5° (±16.1) (p < .001) and mean listhesis reduce from 63.2% (±21.9) to 26.0% (±20.1) (p < .001). Preoperatively, 18 (53%) had neurologic symptoms. At one- and two-year follow-up, new or residual neurologic symptoms were present in four patients (12%) (p < .001). Postoperative symptoms were not significantly related to amount of reduction. Sixteen (47%) underwent reoperation at an average of 24.8 months, 10 for planned prominent instrumentation removal, and 6 for true complications.

CONCLUSIONS

Surgical reduction and decompression of spondylolisthesis in the pediatric population restores spinopelvic alignment. We found no evidence that a greater amount of reduction was associated with a higher incidence of postoperative complications. However, patients should be advised that prominent instrumentation may require future removal. Although previous reports suggest complication rates and permanent neurologic sequelae in up to 20% after operative treatment of spondylolisthesis, our results suggest that a contemporary approach with a two-surgeon team may provide improved results.

LEVEL OF EVIDENCE

Level IV.

The Challenge of Creating Lordosis in High-Grade Dysplastic Spondylolisthesis

High-grade dysplastic spondylolisthesis (HGDS) is a subset of L5-S1 spondylolisthesis that occurs due to dysmorphic anatomy at the lumbosacral junction, often resulting in sagittal imbalance. Enhanced understanding of global sagittal alignment has led many to preferentially treat HGDS with reduction and fusion to restore sagittal balance. The purpose of this article is to review published surgical techniques for obtaining sagittal correction in HGDS and to evaluate the current evidence regarding the associated surgical complications.

L5 incidence: an important parameter for spinopelvic balance evaluation in high-grade spondylolisthesis

BACKGROUND

In high-grade spondylolisthesis (HGSPL), the pelvic incidence (PI) is not a reliable measurement because of doming of the sacrum. Measurement of L5 incidence (L5I) was described as a tool to measure pelvic morphology in HGSPL and for surgical follow-up.

OBJECTIVE

We aimed to evaluate L5I in HGSPL and its relationship to other spinopelvic parameters.

STUDY DESIGN

A retrospective study of a cohort of 184 patients with HGSPL was carried out.

METHODS

Whole spine radiographs were analyzed for PI, pelvic tilt (PT), sacral slope, lumbar lordosis (LL), L5I, L5 tilt (L5T), L5 slope, lumbosacral kyphosis, and slip percentage. Statistical analysis and correlation were made (Pearson correlation test; p<.05). In accordance to Cohen, statically significant correlation were considered strong if R>0.5, moderate if 0.3<R<0.5, and small if R<0.3.

RESULTS

A total of 184 cases were analyzed, with a female-to-male ratio of 2.35 and a mean age of 20.1 years. Sacral doming was present in 73% of the cases. Mean L5I incidence was 65.2° and strongly correlated to other sagittal parameters, especially PT (R=0.7), LL (R=0.7), L5T (R=0.77), and L5 slope (R=0.83). There was less but still strong correlation to Dubousset lumbosacral kyphosis (Dub-LSK) angle (R=-0.63) and percentage of slippage (R=0.56). L5 tilt showed nearly perfect correlation to PT (R=0.95). Forty-four percent of the cases were balanced HGSPL, whereas 56% of the cases were unbalanced HGSPL. L5 incidence was found to be a good predictor of local imbalance with a cutoff of L5I=61.

CONCLUSION

This paper describes L5I, which is a positional parameter in HGSPL. L5 incidence is a simple and reliable measure in the preoperative setting in HGSPL. Its correlation with spinal sagittal parameters (especially PT and LL) is strong and was found to be better than Dub-LSK. There is also a good correlation between L5I and HGSPL pelvic parameters (slip percentage and lumbosacral kyphosis). We recommend its use for evaluation of surgical correction and recommend the value of 60° as cutoff value to define spinopelvic balance in HGSPL.

New method for correction of lumbo-sacral kyphosis deformity in patient with high pelvic incidence

STUDY DESIGN

Technical note.

OBJECTIVE

We describe a novel technique of bilateral longitudinal sacral osteotomy allowing direct reduction of high pelvic incidence (PI) and correction of sagittal imbalance.

METHODS

A 25-year-old female patient presented with a disabling lumbo-sacral kyphosis fused in situ through previous operations with residual low-grade wound infection and grade IV L5/S1 spondylolisthesis with severity index (SI) of 65%. A two-stage correction was performed. First anterior in situ fixation of the L4-L5-S1 segments was performed using a hollow modular anchorages (HMA) screw and L3/L4 anterior interbody cage. The second stage consisted of instrumentation of the lower lumbar spine and pelvis; placement of an S1 transverse K-wire as pivot point and bilateral longitudinal sacral osteotomy which allowed for gradual retroversion of the central sacrum relative to the pelvis.

RESULTS

Sacrum was derotated by 30° which allowed to restore spinal sagittal balance and decrease SI by 15%. Postoperative recovery was complicated by a flare up of the pre-existing deep wound infection.

CONCLUSIONS

Bilateral longitudinal sacral osteotomy appears to be a safe and efficient way of correcting the sagittal imbalance caused by an extremely high PI. Although technically demanding, it achieves good radiological and functional outcomes and avoids entering the spinal canal.

Which is the optimum surgical strategy for spondylolisthesis: Reduction or fusion in situ? A meta-analysis from 12 comparative studies

PURPOSE

To compare the clinical outcomes and complications and radiographic outcomes of the two different surgical strategies (arthrodesis in situ and arthrodesis following reduction) for the surgical management of spondylolisthesis.

METHODS

After systematic search the PubMed, Ovid MEDLINE, Cochrane, and Embase databases, comparative studies were selected according to eligibility criteria. Checklists by Furlan and by The Newcastle-Ottawa quality assessment scale (NOS scale) were used to evaluate the risk of bias of the included randomized clinical trials (RCTs) and nonrandomized controlled studies, respectively. The final strength of evidence was expressed as different levels recommended by the GRADE Working Group.

RESULTS

Three RCTs. and nine comparative observational studies were identified. Low-quality evidence indicated that reduction group (RG) was not more effective than fusion in situ group for clinical satisfaction (OR 0.77, 95% CI 0.39-1.54, P = 0.46). and neurologic complication rate (OR 0.89, 95 CI 0.38-2.03, P = 0.78). In secondary outcomes, Low-quality evidence indicated that RG improved fusion rate (OR 2.66, 95% CI 1.15-6.14, P = 0.02). There was no significant difference in the other complication rate (OR 0.89, 95% CI 0.44-1.79, P = 0.63) and blood loss (WMD 14.22, 95% CI -9.53-37.79, P = 0.24) between two groups. Statistical difference was found between the two groups with regard to slipping angle (WMD -6.33, 95% CI -12.60 to -0.06, P = 0.05).

CONCLUSIONS

There was no definite benefit of reduction over fusion in situ in clinical satisfaction rate and neurologic complication rate. The fusion rate significantly improved while the slipping angle considerably decreased postoperation in reduction group.

Results of the Scoliosis Research Society Morbidity and Mortality Database 2009-2012: A Report From the Morbidity and Mortality Committee

INTRODUCTION

Members of the Scoliosis Research Society are required to annually submit complication data regarding deaths, visual acuity loss, neurological deficit and infection (2012-1st year for this measure) for all deformity operations performed. The purpose of this study is to report the 2012 results and the differences in these complications from the years 2009-2012.

METHODS

The SRS M&M database is a self-reported complications registry of deformity operations performed by the members. The data from 2009-2012, inclusive, was tabulated and analyzed. Differences in frequency distribution between years were analyzed with Fisher's exact test. Significance was set at α = 0.05.

RESULTS

The total number of cases reported increased from 34,332 in 2009 to 47,755 in 2012. Overall mortality ranged from 0.07% in 2011 to 0.12% in 2009. The neuromuscular scoliosis group had the highest mortality rate (0.44%) in 2010. The combined groups' neurological deficit rate increased from 0.44% in 2009 to 0.79% in 2012. Neurological deficits were significantly lower in 2009 compared to 2012 for idiopathic scoliosis >18 years, other scoliosis, degenerative and isthmic spondylolisthesis and other groups. The groups with the highest neurological deficit rates were dysplastic spondylolisthesis and congenital kyphosis. There were no differences in vision loss rates between years. The overall 2012 infection rate was 1.14% with neuromuscular scoliosis having the highest group rate at 2.97%.

CONCLUSION

Neuromuscular scoliosis has the highest complication rates of mortality and infection. The neurological deficit rates of all groups combined have slightly increased from 2009 to 2012 with the highest rates consistently being in the dysplastic spondylolisthesis and congenital kyphosis groups. This could be due to a number of factors, including more rigorous reporting.

Operative management of high-grade dysplastic L5 spondylolisthesis with the use of external transpedicular fixation: advantages and drawbacks

PURPOSE

The aim of our study was to analyze clinical and radiographic outcomes of operative management of L5 high-grade dysplastic spondylolisthesis with the apparatus for external transpedicular fixation (AETF), and to compare the results of its use for reduction and spondylodesis.

METHODS

There were 13 patients with L5 dysplastic spondylolisthesis of grade 4 (Meyerding grading) and having a mean age of 25.0 ± 3.6 years. The management included two stages: gradual reduction with the AETF, followed by either isolated anterior spondylodesis with the same AETF (group 1, n = 8), or by spondylodesis using a combined method (internal transpedicular instrumentation and posterior lumbar interbody fusion [PLIF]) (group 2, n = 5). Clinical evaluation included pain (VAS scale) and functional status (Oswestry questionnaire [ODI]). Reduction and fusion completeness were assessed radiographically after treatment and at a mean follow-up of 2.1 ± 0.4 years.

RESULTS

Initial slippage was reduced by 51.6 % with AETF and was of grade 1 or 2. Reduction made up 31.1 % at follow-ups (grade 2 or 3). Pain decreased by 57.6 % (p < 0.01). The functional status improved. ODI decreased by 37.7 % (p < 0.01) after treatment and by 41.7 % (p < 0.01) at follow-ups. Fusion at the level of the involved segment was poor in group 1. All the cases fused in group 2.

CONCLUSIONS

The use of AETF for L5 high-grade dysplastic spondylolisthesis provides gradual controlled reduction of the slipped vertebra, decompression of cauda equine roots, and recovery of the local sagittal spinal column balance. It creates conditions for achieving stability of lumbosacral segments with combined spondylodesis (internal transpedicular instrumentation and PLIF). AETF is not suitable for spondylodesis due to a high rate of pseudarthrosis.

Posterior reduction and monosegmental fusion with intraoperative three-dimensional navigation system in the treatment of high-grade developmental spondylolisthesis

Background:

The treatment of high-grade developmental spondylolisthesis (HGDS) is still challenging and controversial. In this study, we investigated the efficacy of the posterior reduction and monosegmental fusion assisted by intraoperative three-dimensional (3D) navigation system in managing the HGDS.

Methods:

Thirteen consecutive HGDS patients were treated with posterior decompression, reduction and monosegmental fusion of L5/S1, assisted by intraoperative 3D navigation system. The clinical and radiographic outcomes were evaluated, with a minimum follow-up of 2 years. The differences between the pre- and post-operative measures were statistically analyzed using a two-tailed, paired t-test.

Results:

At most recent follow-up, 12 patients were pain-free. Only 1 patient had moderate pain. There were no permanent neurological complications or pseudarthrosis. The magnetic resonance imaging showed that there was no obvious disc degeneration in the adjacent segment. All radiographic parameters were improved. Mean slippage improved from 63.2% before surgery to 12.2% after surgery and 11.0% at latest follow-up. Lumbar lordosis changed from preoperative 34.9 ± 13.3° to postoperative 50.4 ± 9.9°, and 49.3 ± 7.8° at last follow-up. L5 incidence improved from 71.0 ± 11.3° to 54.0 ± 11.9° and did not change significantly at the last follow-up 53.1 ± 15.4°. While pelvic incidence remained unchanged, sacral slip significantly decreased from preoperative 32.7 ± 12.5° to postoperative 42.6 ± 9.8°and remained constant to the last follow-up 44.4 ± 6.9°. Pelvic tilt significantly decreased from 38.4 ± 12.5° to 30.9 ± 8.1° and remained unchanged at the last follow-up 28.1 ± 11.2°.

Conclusions:

Posterior reduction and monosegmental fusion of L5/S1 assisted by intraoperative 3D navigation are an effective technique for managing high-grade dysplastic spondylolisthesis. A complete reduction of local deformity and excellent correction of overall sagittal balance can be achieved.

[Spondylolysis and spondylolisthesis in children and adolescents]

Low back pain is a common cause of lost playing time in young athletes, and spondylolysis is its most common identifiable cause. Despite technological advances in radiology, which can lead to an early diagnosis with better prognosis, progression to spondylolisthesis is sometimes asymptomatic and may not be detected until late stages. There are wide variations, suggesting lack of consensus as regards the objective of treatment, which consists of clinical, radiological, biomechanical or functional improvement. There is also a lack of agreement regarding the ideal conservative treatment, surgical indications and need of slip reduction, and most of the established recommendations are not evidence based. We present a review of literature, which summarizes the current knowledge of spondylolysis and spondylolisthesis in children and adolescents.

Sacrum pubic incidence and sacrum pubic posterior angle: two morphologic radiological parameters in assessing pelvic sagittal alignment in human adults

PURPOSE

The morphology and position of pelvis are critical in regulating the biomechanical organization of spine-pelvis-leg in the sagittal plane. Several radiological parameters have been developed to present the sagittal morphology of the pelvis such as pelvic incidence (PI) and Jackson's angle (PRS1). In addition, the femoral sacral posterior angle (FSPA) was developed for patients with a dome-shaped deformity in the upper plate of the sacrum. The identification of hip axis, which was represented by the line connecting the centers of femoral heads in normal subjects, was important for these parameters measurement. However, in subjects with fused hip joint or deformed femoral heads, the accurate localization of hip axis become imprecise. Herein, the upper edge of the pubic symphysis, which is easy to identify on the lateral X-ray film, was selected as an alternative landmark of the hip axis, and two morphologic parameters, the sacrum pubic incidence (SPI) and sacrum pubic posterior angle (SPPA), were proposed accordingly. The present study aimed to understand the reliability of these two parameters and their value in predicting PI, PRS1 and FSPA.

METHODS

Upright standing spine and pelvis radiographs of 60 normal adults (30 male and 30 female) with an average age of 38.5 years were obtained. Two independent observers then measured the following radiological parameters on the films: PI, PRS1, FSPA, SPI, SPPA, sacral slope, pelvic tilt and lumbar lordosis. The SPI is the angle between the line perpendicular to the superior plate of the first sacral vertebra at its midpoint and the line connecting this point to the upper edge of the pubic symphysis, while the SPPA is the angle between the line extending from the posterior upper edge of the sacrum to the upper edge of the pubic symphysis and the posterior side of the first sacral vertebral body. The intra-observer and inter-observer reliabilities of the parameters were analyzed using intraclass correlations. The correlations between parameters were analyzed by Pearson's correlation coefficients. Regression analysis was carried out to establish formulas to predict the values of PI, PRS1 and FSPA using the SPI and SPPA. A p < 0.05 was considered statistically significant.

RESULTS

The SPI was 64.4° ± 9.5° and 68.3° ± 9.4°, and the SPPA was 77.7° ± 7.5° and 78.7° ± 9.4° in males and females, respectively. These radiological parameters showed excellent intra- and inter-observer reliabilities, with an intraclass correlation >0.8. No gender differences were identified in these morphologic and positional radiological parameters. The SPI demonstrated strong correlation with PI and PRS1 (R (2) > 0.9, p < 0.001). In addition, strong correlation was also found between SPPA and FSPA (R (2) > 0.9, p < 0.001). Furthermore, both SPPA and FSPA showed close correlations with the other morphologic and positional parameters. Linear regression analysis established equations to predict PI and PRS1 using SPI and to predict FSPA by SPPA with significantly high reliability.

CONCLUSIONS

Both SPI and SPPA are reliable parameters for determining the morphology of the pelvis. The SPI is precise in predicting PI and PRS1, while SPPA is reliable in predicting FSPA. The SPI and SPPA will allow further study on lateral spinal-pelvic alignment in patients with hip joint abnormalities.

High-grade lumbosacral spondylolisthesis reduction and fusion in children using transsacral rod fixation

PURPOSE

There is no consensus on how to treat surgically high-dysplastic developmental spondylolisthesis in children and adolescents. Although reducing spinal deformity seems mandatory, the issue of surgical reduction versus in situ fusion remains controversial.

METHODS

The files of 12 consecutive patients surgically treated for a grade 3 or 4 spondylolisthesis were reviewed. The treatment consisted in L4 to sacrum reduction and fusion by posterior approach. The reduction of lumbopelvic imbalance was made intraoperatively using a trans-sacral rod fixation technique.

RESULTS

Mean preoperative L5 anterior slippage was 72.3 % (60 to 95 %). The mean preoperative lumbosacral tilt angle was 70.5° (43 to 92°). Mean final lumbosacral tilt angle was 102° (91 to 114°). Mean final L5 anterior slippage was 19 % (7 to 63 %). Neurological complications (radicular L5 or S1 deficits) were noted in five patients. At final follow-up L4 to S1 fusion was achieved in all patients. No patient had persistent deficit or radicular pain.

CONCLUSIONS

The fusion rate in our series proved to be optimal. Thanks to the trans-sacral rod fixation, lumbosacral kyphosis correction was very good. The intrasacral positioning of the screws reduces the risk of implant prominence especially in such pediatric patients. We stress the importance to avoid complete slip reduction in such patients to minimize stretching on L5 and S1 roots. No additional immobilization is needed due to solid posterior instrumentation. Doing such procedure only by posterior approach avoids anterior approach-related complications.

Analysis of L5 incidence in normal population use of L5 incidence as a guide in reconstruction of lumbosacral alignment

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To establish a statistic model defining the relationship between L5 incidence (L5I) and pelvic incidence (PI) in normal population and to illustrate the importance of L5I in maintaining the normal sagittal profile of spine.

SUMMARY OF BACKGROUND DATA

L5I was proposed for the evaluation of postoperative improvements in high-grade isthmic spondylolisthesis. It has been proven that a postoperative improvement in L5I was correlated with a better surgical outcome, indicating that the restoration of L5I is important in restoring normal sagittal balance and spinal morphology.

METHODS

This retrospective study recruited 138 healthy volunteers, who were stratified into 2 groups according to age: adolescent group (13-18 yr) and adult group (19-35 yr). Parameters including PI, pelvic tilt, sacral slope, lumbar lordosis (LL), upper arc of the LL, lower arc of the LL, L5I, lumbosacral angle, and height of L5-S1 disc were measured on the long-cassette standing upright lateral radiographs of the spine and pelvis. The relations between all parameters were determined via the Pearson correlation coefficient (r). Linear regression was applied to model the relationship between PI and L5I.

RESULTS

This study demonstrated significant correlation between L5I and PI with a coefficient of 0.818, and a formula based on linear regression was established to estimate the ideal L5I from PI as follows: L5I = 0.725 PI - 12.757. Pelvic tilt, sacral slope, lumbosacral angle, LL, lower arc of the LL, and height of L5-S1 disc were also found strongly correlated with L5I, whereas no correlation was found between upper arc of the LL and L5I.

CONCLUSION

Strong correlations were found between L5I and spinopelvic parameters in healthy subjects, indicating that L5I was an important parameter in local lumbosacral alignment. Ideal postoperative L5I could be mathematically calculated by PI according to the formula as follows: L5I = 0.725 PI - 12.757, suggesting that calculated ideal L5I could be regarded as a guide in surgical decision making.

LEVEL OF EVIDENCE

3.

The relationship between spinopelvic parameters and clinical symptoms of severe isthmic spondylolisthesis: a prospective study of 64 patients

PURPOSE

To investigate the relationship between spinopelvic parameters and clinical symptoms for patients with severe isthmic spondylolisthesis.

METHODS

A series of spinopelvic parameters were measured in 64 patients with L5 severe isthmic spondylolisthesis. The patients were divided into two groups according to Oswestry score obtained preoperatively, i.e. mild or severe low back pain group. T test was used to compare parameters between two groups, and multiple linear regression analysis was employed to investigate the association between parameters and Oswestry score.

RESULTS

Compared with two group patients, parameters of spondylolisthesis grade, pelvic tilt (PT), lumbar lordosis (LL), T9 tilting angle (T9TA), sacro-femoral horizontal distance (SFHD), distance between perpendicular line through C7 and sacrum (SC7D), pelvic tilt/sacral slope (PT/SS), sacro-femoral horizontal distance/vertical distance (SFHD/SFVD), and lumbar lordosis/thoracic kyphosis (LL/TK) were significantly increased in severe low back pain group, while SS and SFVD were significantly decreased, and no significant difference was found for pelvic incidence (PI) and TK. The statistical analysis showed that spondylolisthesis grade, PT, SC7D, LL, SFHD, PT/SS, SFHD/SFVD, and LL/TK had a significant positive correlation with Oswestry score, with an order of spondylolisthesis grade > PT/SS > SC7D > PT > SFHD/SFVD > SFHD > LL/TK > LL. No significant correlation was found for PI, TK, T9TA with Oswestry score, while SS and SFVD had a significant negative correlation with Oswestry score, with an order of SS > SFVD.

CONCLUSIONS

The spinopelvic parameters (spondylolisthesis grade, SS, PT, SC7D, LL, SFVD, SFHD, PT/SS, SFHD/SFVD, LL/TK) are significantly correlated with clinical symptoms of severe isthmic spondylolisthesis in patients. The association of the exacerbation of low back pain with SS (correlation coefficient -0.981, strong) and SFVD (correlation coefficient -0.802, strong) is the most significant correlation.

"In situ" fusion or reduction in high-grade high dysplastic developmental spondylolisthesis (HDSS)

PURPOSE

To assess if the evaluation of the spino-pelvic balance can be effective in the surgical decision making of the high-grade high dysplastic developmental spondylolisthesis (HDDS).

METHODS

Sixteen patients affected with high-grade HDDS (6 treated with "in situ" fusion, and 10 with reduction and fusion) were retrospectively evaluated. A clinical and radiological assessment of the deformity correction was carried out, with a minimum follow-up of 2 years. The differences between the pre- and postoperative measures were statistically analyzed using a two-tailed, paired t test.

RESULTS

The six patients treated with "in situ" fusion showed no statistically significant change at the last follow-up relative to pelvic tilt (PT), sacral slope (SS), and grade, while the 10 patients treated with reduction showed significant changes: PT significantly decreased following surgery, while SS and grade significantly increased.

CONCLUSIONS

The analysis of the spino-pelvic sagittal balance allows to identify two types of HDDS: the balanced deformities, which do not need reduction, and the unbalanced deformities, in which correction is needed.