Sagittal Balance and Health-Related Quality of Life Three Decades After in Situ Arthrodesis for High-Grade Isthmic Spondylolisthesis

A Surgical Treatment Algorithm for Restoring Pelvic Balance and Health-related Quality of Life in High-grade Lumbosacral Spondylolisthesis: Prospective Multicenter Cohort of 61 Young Patients

STUDY DESIGN

Retrospective multicenter cohort-study.

OBJECTIVE

We propose an evidence-based surgical algorithm for achieving normal pelvic balance while optimizing health-related quality of life (HRQoL) in high-grade spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The principles of surgical treatment for young patients with high-grade L5-S1 spondylolisthesis remain unclear. There is a growing body of evidence supporting the central role of pelvic balance in the postural control and biomechanics of subjects with high-grade spondylolisthesis.

METHODS

This retrospective study assessed a multicenter cohort of 61 patients with high-grade L5-S1 spondylolisthesis. Classification and regression tree analysis was used to identify objective criteria associated with pelvic balance and HRQoL after surgery.

RESULTS

The most important predictor of a postoperative balanced pelvis was a postoperative L5 incidence ≤63.5 degrees. With postoperative L5 incidence ≤63.5 degrees,a residual slip percentage 9% and performing an L5-S1 posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) increased the likelihood of achieving a balanced pelvis postoperatively. When L5 incidence was 63.5 degrees,a balanced pelvis was most likely achieved with fusion limited to L5 proximally, residual slip percentage ≤40%, and residual lumbosacral angle 98 degrees. Predictors of postoperative HRQoL were the preoperative HRQoL score, L5 incidence and slip percentage.

CONCLUSIONS

A surgical algorithm is proposed to achieve normal pelvic balance, while optimizing HRQoL. The first step during surgery is to assess L5 incidence and if L5 incidence is <65 degrees, the next step depends on the pelvic balance. With a preoperative balanced pelvis, it is important not to reduce completely the slip percentage by leaving a slip percentage ≥10%. When the preoperative pelvis is unbalanced, a TLIF/PLIF at L5-S1 is recommended to facilitate correcting the angular deformity at L5-S1. If L5 incidence is ≥65 degrees,a TLIF/PLIF at L5-S1 should be performed to correct the angular deformity at L5-S1, and fusion should ideally end at L5 proximally, in addition to performing gradual reduction of the slip percentage. If fusion up to L4 is required, a lumbosacral angle ≥100 degrees is key.

From the Spinopelvic Parameters to Global Alignment and Proportion Scores in Adult Spinal Deformity

In the last 20 years, sagittal alignment and balance of the spine have become one of the most important issues in the field of spine surgery. Recent studies emphasize that sagittal balance and alignment are more important for health-related quality of life. The understanding of normal and abnormal sagittal alignment of the spine is necessary for the diagnosis and appropriate treatment of adult spinal deformity (ASD), and we will discuss the currently used classification of ASD, the parameters of sagittal alignment that are essential for the diagnosis of spinal deformity, compensatory actions to maintain sagittal balance, and the relationship between sagittal alignment and clinical symptoms. Furthermore, we will also discuss the recently introduced Global Alignment and Proportion scores. The Korean Spinal Deformity Society is publishing a series of review articles on spinal deformities to help spine surgeons better understand spinal deformities.

Stretch on the L5 nerve root in high-grade spondylolisthesis reduction

OBJECTIVE

L5 nerve root (L5-NR) injury after surgery for high-grade spondylolisthesis (HGS) was considered a nerve stretch associated with reduction. Currently, however, no study has directly measured the stretch on the L5-NR during HGS reduction procedures.

METHODS

CT data of 4 patients with mild lumbar degeneration (control group [CG]) and 4 patients with HGS (spondylolisthesis group [SG]) were used for 3D printing to develop L5 vertebrae and sacrum models. These models were mounted on a self-designed reduction apparatus, which performed vertical translation (disc heights of 0, 5, and 10 mm), anterior-posterior translation (reduction, 0%-100%), and slip-angle correction (0° to -30°). The L5-NR was simulated by using a rabbit sciatic nerve. The cephalic side of the nerve was fixed at the upper base of the L5 pedicle, while the caudal side was connected to a high-precision sensor and an indicator to measure the tension (stretch) on the nerve during the reduction procedures in real time.

RESULTS

The SG had shorter L5-NRs than the CG. At a 0-mm disc height, the peak tension on the L5-NR changed from 0 N (reduction 0%) to 1.81 ± 0.54 N (reduction 100%) in the SG and to 1.78 ± 0.71 N in the CG. At a 10-mm disc height, the tension changed from 1.50 ± 0.67 N to 4.97 ± 1.04 N in the SG and from 0.92 ± 0.45 N to 3.26 ± 0.88 N in the CG. In both the CG and SG, at the same disc height, all values from the complete reduction process were statistically significant. Furthermore, at the same degree of reduction, the comparisons between different disc heights were almost all statistically significant. Intergroup comparisons showed that an increased disc height would cause more tension on the L5-NR in the SG than in the CG. At a 10-mm disc height, all results between the groups demonstrated statistical significance. The slip-angle correction produced a slight increase in the tension on the L5-NR in both groups.

CONCLUSIONS

Increased disc height and reduction significantly increased the tension on the L5-NR, which demonstrated a nonlinear curve. The slip-angle correction from 0° to -30° slightly increased the tension on the L5-NR. Under the same degree of reduction and restored disc height, the SG had more tension on the L5-NR than the CG.

Lordosis Distribution Index in Short-Segment Lumbar Spine Fusion - Can Ideal Lordosis Reduce Revision Surgery and Iatrogenic Deformity?

OBJECTIVE

The demand for spinal fusion is increasing, with concurrent reports of iatrogenic adult spinal deformity (flatback deformity) possibly due to inappropriate lordosis distribution. This distribution is assessed using the lordosis distribution index (LDI) which describes the upper and lower arc lordosis ratio. Maldistributed LDI has been associated to adjacent segment disease following interbody fusion, although correlation to later-stage deformity is yet to be assessed. We therefore aimed to investigate if hypolordotic lordosis maldistribution was associated to radiographic deformity-surrogates or revision surgery following instrumented lumbar fusion.

METHODS

All patients undergoing fusion surgery ( ≤ 4 vertebra) for degenerative lumbar diseases were retrospectively included at a single center. Patients were categorized according to their postoperative LDI as: "normal" (LDI 50-80), "hypolordotic" (LDI < 50), or "hyperlordotic" (LDI > 80).

RESULTS

We included 149 patients who were followed for 21 ± 14 months. Most attained a normally distributed lordosis (62%). The hypolordotic group had increased postoperative pelvic tilt (PT) (p < 0.001), pelvic incidence minus lumbar lordosis (PI-LL) mismatch (p < 0.001) and decreased global lordosis (p = 0.007) compared to the normal group. Survival analyses revealed a significant difference in revision surgery (p = 0.03), and subsequent multivariable logistic regression showed increased odds of 1-year revision in the hypolordotic group (p = 0.04). There was also a negative, linear correlation between preoperative pelvic incidence (PI) and postoperative LDI (p < 0.001).

CONCLUSION

In patients undergoing instrumented lumbar fusion surgery, hypolordotic lordosis maldistribution (LDI < 50) was associated to increased risk of revision surgery, increased postoperative PT and PI-LL mismatch. Lordosis distribution should be considered prior to spinal fusion, especially in high PI patients.

L5 Radiculopathy After Formal Reduction of High-Grade SDSG Type 5 and 6 L5-S1 Isthmic Spondylolisthesis with 2-Year Follow-Up

BACKGROUND

Surgery is the main treatment for patients with high-grade L5-S1 isthmic spondylolisthesis, which can result in neurologic complications, but little is known about its clinical course. The present study evaluated the presence of L5 radiculopathy in high-grade L5-S1 spondylolisthesis in adults in pre- and postoperative periods and after a 2-year follow-up.

METHODS

A series of 16 patients who underwent reduction and instrumented fusion for high-grade 5 and 6 spondylolisthesis between 2018 and 2019 were retrospectively evaluated in the pre- and postoperative periods as well as after 6 weeks, 3 months, 6 months, and 1 and 2 years of follow-up. Clinical and surgical data on possible neurological complications of L5 radiculopathy were prospectively collected.

RESULTS

The age was 20.1 ± 12.0 years, and preoperative L5-S1 slip was 89.0%. Five patients presented motor deficit in the preoperative period. In the immediate postoperative period, 9 patients (56%) experienced motor deficits or worsening of the preoperative condition. At the 6-week follow-up, only 1 patient showed resolution of the motor deficit. Three patients presented healed motor deficits after 3 months, and 1 patient demonstrated a healed L5 motor radiculopathy after 6 months. At the 1-year follow-up, only 1 patient exhibited an L5 radiculopathy motor deficit, and at the 2-year follow-up, none of the patients exhibited an L5 radiculopathy motor deficit.

CONCLUSION

L5 radiculopathy was frequent in the preoperative period and increased after reduction and instrumented fusion of high-grade L5-S1 spondylolisthesis in the postoperative period and in the 6-week follow-up. Three and 6 months after the surgery, there were consecutive motor improvements. After 2 years of follow-up, no patients showed neurological deficit of L5 radiculopathy.

LEVEL OF EVIDENCE

2.

CLINICAL RELEVANCE

This is the first study reporting a reduction in complications of L5 neurological motor deficit over a 2-year follow-up in high-grade L5-S1 spondylolisthesis in young adults.

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

Health-related quality of life and sagittal balance at two to 25 years after posterior transfixation for high-grade dysplastic spondylolisthesis

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

Methods

SRS-22r and full-spine lateral radiographs were collected for the 28 young patients (age 13.4 years (SD 2.6) who underwent surgery for high-grade dysplastic spondylolisthesis in our centre (Scottish National Spinal Deformity Service) between 1995 and 2018. The mean follow-up was nine years (2 to 25), and one patient was lost to follow-up. The standard surgical technique was an all-posterior, partial reduction, and S1 to L5 transfixation screw technique without direct decompression. Parameters for segmental (slip percentage, Dubousset’s lumbosacral angle) and regional alignment (pelvic tilt, sacral slope, L5 incidence, lumbar lordosis, and thoracic kyphosis) and global balance (T1 spino-pelvic inclination) were measured. SRS-22r scores were compared between patients with a balanced and unbalanced pelvis at final follow-up.

Results

SRS-22r domain and total scores improved significantly from preoperative to final follow-up, except for the mental health domain that remained the same. Slip percentage improved from 75% (SD 15) to 48% (SD 19) and lumbosacral angle from 70° (SD 11) to 101° (SD 11). Preoperatively, 35% had global imbalance, and at follow-up all were balanced. Preoperatively, 63% had an unbalanced pelvis, and at final follow-up this was 32%. SRS-22r scores were not different in patients with a balanced or unbalanced pelvis. However, postoperative pelvic imbalance as measured by L5 incidence was associated with lower SRS-22r self-image and total scores (p = 0.029).

Conclusion

In young patients with HGDS, partial reduction and transfixation improves local lumbosacral alignment, restores pelvic, and global balance and provides satisfactory long-term clinical outcomes. Higher SRS-22r self-image and total scores were observed in the patients that had a balanced pelvis (L5I < 60°) at two to 25 years follow-up.

Cite this article: Bone Jt Open 2021;2(3):163–173.

Clinical appearance and reliability in visual assessment after in situ fusion for high-grade isthmic spondylolisthesis

PURPOSE

The current literature on clinical appearance after surgery for high-grade spondylolisthesis is inconclusive. The few long-term comparative studies on surgical reduction versus in situ fusion report contradictory findings concerning appearance-related issues. The purpose of the current study was to evaluate and quantify clinical appearance three decades after in situ fusion for high-grade isthmic spondylolisthesis.

METHODS

The Scoliosis Research Society (SRS)-22r questionnaire, digital photographs and standing lateral radiographs were used to evaluate clinical appearance for 22 patients three decades after in situ fusion for high-grade spondylolisthesis. The appearance was assessed by two spine surgeons, by the patient themselves, and by quantification of cosmesis relevant radiographic variables including pelvic parameters and sagittal balance.

RESULTS

The surgeon inter- and intraobserver reliability of the photographic evaluation of the trunk deformity was at most moderate (Cohen's kappa 0.5). Correlation analysis revealed at most medium correlation between radiographic outcome and self-rated (SRS-22r) self-image (Spearman's rank correlation coefficient 0.3). The agreement between patient and surgeon-rated trunk appearance was poor (Cohen's kappa 0.2).

CONCLUSIONS

Photographic evaluation of the trunk deformity in high-grade spondylolisthesis is unreliable. There were only weak correlations between patient self-assessed trunk appearance and radiographic parameters. The results reflect the pronounced subjectivity of cosmesis, and that the trunk deformity in high-grade spondylolisthesis is not easily observed.

LEVEL OF EVIDENCE

IV.

Correlations between radiographic spinopelvic parameters and health-related quality of life: A prospective evaluation of 37 patients with facioscapulohumeral muscular dystrophy

OBJECTIVE

The purpose of this study was to evaluate the relationship between spinopelvic parameters and health-related quality of life.

METHODS

Patients with Facioscapulohumeral muscular dystrophy (FSHD) were asked to volunteer to participate in this study from April 2018 to December 2019. Patient data, including age, sex, body mass index (BMI), and duration of the diagnosis of FSHD were obtained. Short Form (SF-36) questionnaire was completed for all patients. All patients underwent lateral radiography of the whole spine. The radiographic parameters examined were pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), cervical lordosis (CL), T1 spinopelvic inclination (T1 SPI), thoracic kyphosis (TK), Pelvic incidence- lumbar lordosis (PI-LL) and sagittal vertical axis (SVA).

RESULTS

Thirty-seven patients (16 females and 21 males) were included in the study, with a mean age of 39.1 years. The mean duration of diagnosis was 13.5 ± 11.4 years and mean BMI was 24.2 kg/m2. Physical composite score (PCS) was 38.7 and mental composite score (MCS) 60.8 detected. Radiographic analyses included the following: the mean PT was 9.1°, PI 52.1°, SS 43.5°, LL 67.9°, CL 9.8°, T1 SPI -2.5°, TK 23.1°, SVA 37.6 mm. PI-LL was -13.1°. We identified 31 patients with match (left) PI-LL and six patients with mismatch (right) PI-LL.

CONCLUSION

Hyperlordosis inlumbar spine, hypolordosis in cervical spine and negative sagittal balance were the most common spinal misalignments in patients with FSHD. These patients have lower composite PCS than composite MCS. There was a significantly negative correlation between LL, PI-LL and PCS.

LEVEL OF EVIDENCE

Level IV Cross-sectional study.

Adjacent segment disk degeneration three decades after fusion without attempted reduction for high-grade isthmic spondylolisthesis

STUDY DESIGN

Observational study.

OBJECTIVES

To evaluate adjacent segment disk degeneration (ASD) after fusion without attempted reduction at a young age for high-grade isthmic spondylolisthesis. The clinical relevance of ASD remains unclear. Previous studies have shown that spinal fusion is associated with increased ASD but without influence on clinical outcome. Since high-grade spondylolisthesis is a severe kyphotic deformity, one could hypothesize that fusion without attempted reduction in young patients leads to accelerated adjacent segment disk degeneration in adult life.

METHODS

Anterior and posterior disk heights were evaluated on supine radiographs of the spine 8 years and 29 years after fusion without attempted reduction for high-grade spondylolisthesis and also on standing radiographs 8 years and 33 years after surgery. Pelvic parameters were evaluated on standing radiographs obtained 33 years after surgery. Health-related quality of life was evaluated with the Scoliosis Research Society (SRS)-22r questionnaire.

RESULTS

One segment above fusion the anterior disk height significantly decreased on standing radiographs. Two segments above the fusion, the anterior disk height significantly decreased on supine as well as on standing radiographs. The largest reduction was found two segments above the fusion where the disk height was reduced from 33 to 28% of anterior vertebral height between the measurements at mean 8 years and mean 33 years after surgery. There were no statistically significant decreases in posterior disk heights in any measurement. The disk height showed a moderate negative correlation to PT. There was no correlation between disk height reduction and SRS-22r outcome.

CONCLUSIONS

In our long-term follow-up of fusion without attempted reduction for high-grade spondylolisthesis in young patients, we found only a minor but statistically significant reduction in adjacent segment disk height which had no apparent impact on clinical outcome.

LEVEL OF EVIDENCE

Level IV.

High-Grade Spondylolisthesis in Adults: Current Concepts in Evaluation and Management

Background

Information regarding the treatment of high-grade spondylolisthesis (HGS) in adults has been previously described; however, previous descriptions of the evaluation and surgical management of HGS do not represent more recent and now established approaches. The purpose of the current review is to discuss current concepts in the evaluation and management of patients with HGS.

Methods

Literature review.

Results

HGS is diagnosed in up to 11.3% of adults with spondylolisthesis and typically presents as nonspecific lower back pain. Regarding evaluation, a thorough history and physical examination should be performed, which may help predict the presence of HGS. Diagnostic imaging, and specifically the use of spino-pelvic parameters, are now commonly implicated in guiding treatment course and prognosis. When surgical intervention is indicated, surgical approaches include in situ fusion variations, reduction and partial reduction with fusion, and vertebrectomy. Although the majority of studies suggest improvements with these approaches, the literature is limited by a low level of evidence with regards to the superiority of one technique when compared with others.

Conclusions

HGS is a unique cause of low back pain in adults that carries considerable morbidity, but rarely presents with neurologic symptoms. Although the definitions, classifications, and methods of diagnosis of this spinal deformity have been established and accepted, the ideal surgical management of this deformity remains highly debated. Fusion in situ techniques are often technically easier to perform and provide lower risk of neurologic complications, whereas reduction and fusion techniques offer greater restoration of global spino-pelvic balance. Preoperative spino-pelvic parameters may have utility in assisting in procedural selection; however, future, higher-quality and longer-term studies are warranted to determine the optimal surgical intervention among the widely available techniques currently used, and to better define the indications for these interventions.

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.

Restoration of normal pelvic balance from surgical reduction in high-grade spondylolisthesis

PURPOSE

To investigate the effectiveness of surgical reduction in high-grade spondylolisthesis in maintaining or restoring a normal pelvic balance, as related to the QoL.

METHODS

It is a retrospective analysis of prospectively collected data of 60 patients (17 males, 43 females) aged 15 ± 3.1 years who underwent surgery for high-grade spondylolisthesis and were followed for a minimum of 2 years after surgery. Patients with a residual high-grade slip following surgery were referred to the postoperative high-grade (PHG) group, while patients with a residual low-grade slip were referred to the postoperative low-grade (PLG) group. Pelvic balance was assessed from pelvic tilt and sacral slope, in order to identify patients with a balanced pelvis or unbalanced pelvis. The SRS-22 questionnaire was completed before surgery and at last follow-up.

RESULTS

Postoperatively, there were 36 patients with a balanced pelvis and 24 patients with an unbalanced pelvis. The improvement in QoL was better in patients with a postoperative balanced pelvis. There were 14 patients in the PHG group and 46 patients in the PLG group. Four of seven patients (57%) in the PHG group and 21 of 26 patients (81%) in the PLG group with a preoperative balanced pelvis maintained a balanced pelvis postoperatively (P = 0.1). None of the patients in the PHG group and 11 of 20 patients (55%) in the PLG group improved from an unbalanced to a balanced pelvis postoperatively (P < 0.05).

CONCLUSIONS

Surgical reduction in high- to low-grade slip is more effective in maintaining and restoring a normal pelvic balance postoperatively. These slides can be retrieved under Electronic Supplementary Material.