Segmental vertebral three-dimensional motion in patients with L4 isthmic spondylolisthesis under weight-bearing conditions.

OBJECTIVE: To investigate in vivo 6-degree-of-freedom (DOF) vertebral motion in patients with isthmic spondylolisthesis (IS) during various functional weight-bearing activities. METHODS: Fifteen asymptomatic volunteers (mean age 54.8 years) and fourteen patients with IS at L4-5 (mean age 53.4 years) were recruited. The positions of the vertebrae (L4-L5) in the supine, standing, flexion-extension, left-right twisting and left-right bending positions were determined using previously described CT-based models and dual fluoroscopic imaging techniques. Local coordinate systems were established at the center of the anterior vertebra of L4 isthmic spondylolisthesis (AIS), the posterior lamina of L4 isthmic spondylolisthesis (PIS) and the center of the L5 vertebra to obtain the 6DOF range of motion (ROM) at L4-L5 and the range of motion (ROM) between the AIS and the PIS. RESULTS: The translation along the anteroposterior axis at L4-L5 during flexion-extension, left-right bending and left-right twisting was significantly greater than that of the healthy participants. However, the translation along the mediolateral axis at L4-L5 presented paradoxical motion under different positions: the ROM increased in the supine-standing and flexion-extension positions but decreased in the left-right bending and left-right twisting positions. The separation along the anteroposterior axis during flexion was significantly greater than that during standing, on average, reaching more than 1 mm. The separation along the mediolateral axis during standing, flexion and extension was significantly greater than that in the supine position. CONCLUSIONS: This study revealed the occurrence of displacement between the AIS and PIS, primarily in the form of separation during flexion. Symptomatic patients with isthmic spondylolisthesis exhibit intervertebral instability, which might be underestimated by flexion-extension radiographs.

Biomechanical changes of oblique lumbar interbody fusion with different fixation techniques in degenerative spondylolisthesis lumbar spine: a finite element analysis.

OBJECTIVE: There is a dearth of comprehensive research on the stability of the spinal biomechanical structure when combining Oblique Lumbar Interbody Fusion (OLIF) with internal fixation methods. Hence, we have devised this experiment to meticulously examine and analyze the biomechanical changes that arise from combining OLIF surgery with different internal fixation techniques in patients diagnosed with degenerative lumbar spondylolisthesis. METHODS: Seven validated finite element models were reconstructed based on computed tomography scan images of the L3-L5 segment. These models included the intact model, a stand-alone (S-A) OLIF model, a lateral screw rod (LSR) OLIF model, a bilateral pedicle screw (BPS) OLIF model, an unilateral pedicle screw (UPS) OLIF model, a bilateral CBT (BCBT) OLIF model, and an unilateral CBT(UCBT) OLIF model. The range of motion (ROM), as well as stress levels in the cage, L4 lower endplate, L5 upper endplate, and fixation constructs were assessed across these different model configurations. RESULTS: S-A model had the highest average ROM of six motion modes, followed by LSR, UPS, UCBT, BPS and BCBT. The BCBT model had a relatively lower cage stress than the others. The maximum peak von Mises stress of the fixation constructs was found in the LSR model. The maximum peak von Mises stress of L4 lower endplate was found in the S-A model. The peak von Mises stress on the L4 lower endplate of the rest surgical models showed no significant difference. The maximum peak von Mises stress of the L5 upper endplate was found in the S-A model. The minimum peak von Mises stress of the L5 upper endplate was found in the BCBT model. No significant difference was found for the peak von Mises stress of the L5 upper endplate among LSR, BPS, UPS and UCBT models. CONCLUSION: Among the six different fixation techniques, BCBT exhibited superior biomechanical stability and minimal stress on the cage-endplate interface. It was followed by BPS, UCBT, UPS, and LSR in terms of effectiveness. Conversely, S-A OLIF demonstrated the least stability and resulted in increased stress on both the cage and endplates. Combining OLIF with BCBT fixation technique enhanced biomechanical stability compared to BPS and presented as a less invasive alternative treatment for patients with degenerative lumbar spondylolisthesis.

Impact of lumbar fusion on sitting spinopelvic balance: Multisegmental versus monosegmental.

OBJECTIVES: To compare the differences in sagittal spinopelvic parameters between patients receiving monosegmental or multisegmental lumbar fusion and to assess the impact of fusion length on sitting balance. METHODS: The current study recruited 41 patients who had undergone lumbar fusion, consisting of 18 in the monosegmental group and 23 in the multisegmental group. And the control group included 50 lumbar degenerative patients who had no previous spinal fusion surgery. Spinopelvic parameters of patients were assessed: sagittal vertical axis, pelvic tilt, sacral slope, pelvic incidence, thoracic kyphosis, lumbar lordosis, and proximal femur angles. RESULTS: We observed significant differences in sitting TK (P = 0.031), LL (P = 0.012), PT (P = 0.009) and SVA (P = 0.009) among the three groups. When transitioning from standing to sitting, the multisegmental group had the least change in SVA (P = 0.016), PT (P = 0.043), and LL (P = 0.009), with a compensatory increase in TK (P = 0.021). Moderate to strong correlations were found between the change in the LL and those in the SVA (r = -0.548, P = 0.001), PT (r = -0.600, P = 0.001), and SS (r = 0.623, P = 0.001). CONCLUSION: Multisegmental lumbar fusion significantly limits the lumbar mobility and affects the ability to compensate postural changes. Reducing the fusion segments as much as possible is of particular value in preserving lumbar mobility and maintaining the compensatory mechanism of spinopelvis.

Comparison of clinical outcomes and spino-pelvic sagittal balance in degenerative lumbar spondylolisthesis: Minimally invasive oblique lumbar interbody fusion (OLIF) versus transforaminal lumbar interbody fusion (TLIF).

ABSTRACT: Spino-pelvic sagittal parameters are closely related to the lumbar degenerative diseases. The present study aims to compare clinical results and spino-pelvic sagittal balance treated with oblique lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) in patients with degenerative lumbar spondylolisthesis at single segment.We retrospectively reviewed and compared 28 patients who underwent OLIF (OLIF group) and 35 who underwent TLIF (TLIF group). Radiological results were evaluated with disc height (DH), foraminal height (FH), fused segment lordosis (FSL), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and sacral slope (SS). Clinical results were evaluated with the Oswestry Disability Index (ODI) and VAS for back and leg pain.The OLIF group showed higher improvement of DH and FH than the TLIF group at all time points after surgery (P < .05). No significant differences were found in PT, PI, and SS between the 2 groups (P > .05). Significant restoration of spino-pelvic sagittal balance was observed in the 2 groups after surgery. Significant differences in postoperative lumbar lordosis and fused segment lordosis were found between the 2 groups (P < .05). Significant difference in the improvement of symptoms was observed between the 2 groups. The OLIF group had lower VAS scores for back pain and ODI compared after surgery (P < .05).It can be concluded that there are exactly differences in improvement of radiographic parameters between 2 approaches, which confirmed that OLIF is better in restoring spinal alignment. Besides, due to the unique minimally invasive approach, OLIF did exhibit a greater advantage in early recovery after surgery.

Outcome of Osteophytes After Only-Fixation as Treatment for Multilevel Cervical Spondylosis-A Minimum of 12 Months Follow-Up.

OBJECTIVE: This report analyzes the significance of osteophytes in the overall pathologic scheme in patients with single-level or multilevel cervical spinal degeneration. METHODS: From January 2010 to December 2018, 249 patients with cervical spondylosis were surgically treated. The alterations in ventral compression caused by disc bulges, osteophytes, and ligament buckling (disc-osteophye-ligament [DOL] complex) at single or multiple levels were evaluated after surgical treatment that involved only spinal fixation and did not involve any kind of bone or soft tissue decompression. Delayed (≥1 year after surgery) postoperative imaging was available in 165 patients and these patients formed the study group. Forty-five patients underwent facet distraction arthrodesis (group A), 106 patients underwent only-fixation involving transarticular screw insertion (group B), and 14 patients underwent hybrid fixation that involved both intra-articular spacers and transarticular fixation techniques (group C) as the surgical treatment. RESULTS: The size of the DOL complex at the segments that underwent fixation was reduced in 136 patients. The size of the DOL complex or its related dural or neural compression did not increase in any of the cases evaluated. Reduction in the size of DOL was more pronounced in patients in group A in both immediate postoperative and delayed images and in patients in group C at spinal levels at which facet distraction was performed using facet distraction spacers. CONCLUSIONS: Spinal stabilization reduces the size of osteophytes. Facet distraction spacers are more effective in reduction of the size of DOL in both immediate and delayed postoperative periods.

Assessment of disability levels in patients with low back pain based on the type of lumbar spinal disorder.

BACKGROUND: Low back pain (LBP) is a common health condition and the leading cause of activity limitation and absenteeism in most parts of the world. One-fifth of patients with LBP develop chronic pain disability. OBJECTIVE: This study investigated the disability levels in patients with different types of lumbar spinal disorders. METHODS: A total of 528 patients visiting spine clinics between June 2017 and February 2018 were enrolled in this study. A demographic checklist, the patients' medical records, the Oswestry Disability Questionnaire, and the Visual Analog Scale (VAS) were used to collect the data. RESULTS: Non-specific LBP (29.5%) and discopathy (27%) were the most common final diagnoses. The obtained Oswestry Disability Index (ODI) was significantly higher in older patients, those with higher body mass index, more work experience, and smokers. Lower ODI was found in individuals with a history of regular exercise. Most individuals in all diagnostic groups were categorized into the high ODI group (p⩽ 0.001). CONCLUSION: In patients with lumbar spine lesions, ODI is significantly correlated with age, BMI, work experience, smoking, and the type of disorder (discopathy, spondylolysis, and spondylolisthesis). Regular exercise is associated with lower levels of disability.

Preoperative and Postoperative, Three-dimensional Gait Analysis in Surgically Treated Patients With High-grade Spondylolisthesis.

BACKGROUND: High-grade spondylolisthesis (HGS) (Myerding grade III-V) in adolescents can lead to a marked alteration of gait pattern and maybe the presenting symptom in these patients. This characteristic gait pattern in patients with HGS has been referred to as the "pelvic waddle." Modern 3-dimensional (3D) gait analysis serves an important tool to objectively analyze the different components of this characteristic gait preoperatively and postoperatively and is an objective measure of postoperative improvement.This study demonstrates the use of 3D gait analysis preoperatively and postoperatively in a cohort of 4 consecutive patients with HGS treated surgically at a single tertiary referral center and utilize this to objectively evaluate outcome of surgical treatment in these patients. This has not been reported previously in a cohort of patients. METHODS: This is a prospective analysis of patients with HGS who underwent surgical intervention for spondylolisthesis at a single institution. Patient demographics, clinical, and radiologic assessment were recorded, and all patients underwent 3D gait analysis before and after surgical intervention. Kinetic, kinematic, and spatial parameters were recorded preoperatively and postoperatively for all patients. This allowed the outcome of change in gait deviation index, before and after surgical treatment, to be evaluated. RESULTS: We were able to review complete records of 4 adolescent patients who underwent surgical treatment for HGS. Mean age at surgery was 13.5 years with a minimum follow-up of 2.5 years postoperatively (average 40 mo). Preoperative gait analysis revealed marked posterior pelvic tilt in 2 patients, reduced hip and knee extension in all 4 patients and external foot progression in 3 of the 4 patients. Along with an observed improvement in gait, there was an objective improvement in gait parameters postoperatively in all 4 patients. Gait deviation index score improved significantly from 78.9 to 101.3 (mean). CONCLUSIONS: Preoperative gait abnormalities exist in HGS and can be objectively analyzed with gait analysis. Surgical intervention may successfully resolve these gait abnormalities and gait analysis is a useful tool to assess the outcome of surgery and quantify an otherwise intangible benefit of surgical intervention. LEVEL OF EVIDENCE: Level IV-case series.

Comparison of unilateral and bilateral polymethylmethacrylate-augmented cannulated pedicle screw fixation for the management of lumbar spondylolisthesis with osteoporosis.

BACKGROUND: Cannulated pedicle screw (CPS) augmented by polymethylmethacrylate (PMMA) can achieve satisfactory clinical efficacy in the treatment of lumbar spondylolisthesis with osteoporosis. However, accurate application of CPSs will help to avoid the difficulty of screw revision and reduce the incidence of PMMA-related complications. This study aimed to investigate the mid-term efficacy of CPS compared to unilateral and bilateral applications in this common lumbar degenerative disease. METHODS: May 2011 and May 2018, 50 patients with lumbar spondylolisthesis with osteoporosis who underwent posterior fixation and fusion using traditional pedicle screws or CPSs were included in the study. Patients were divided into two groups based on the application: the unilateral PMMA-augmented CPS group (UC, n = 29) and the bilateral PMMA-augmented CPS group (BC, n = 21). Operation time, blood loss, average hospitalization time, PMMA leakage, and other complications were recorded. The visual analog scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate symptom recovery. Radiographic results were compared for intervertebral fusion and screw loosening. RESULTS: There were no significant differences in the baseline data of the two groups. The VAS and ODI scores improved significantly after surgery (P < 0.05), with no significant differences between the groups (P > 0.05). The operation time and blood loss in the UC group were significantly lower than those in the BC group (P < 0.05). However, the loss of intervertebral disk height and Taillard index did not differ significantly between the groups. The rates of PMMA leakage in the UC and BC groups were 7.0% and 11.9%, respectively (P < 0.05). Bony fusion was achieved in all groups without screw loosening at the last follow-up. Only one patient experienced superficial infection in both groups, while cerebrospinal fluid leakage was observed in two patients in the BC group. CONCLUSIONS: Unilateral application of PMMA-augmented CPS may provide adequate clinical safety and effectiveness in the surgical treatment of lumbar spondylolisthesis with osteoporosis.

Lumbar degenerative disease after oblique lateral interbody fusion: sagittal spinopelvic alignment and its impact on low back pain.

BACKGROUND: We determined the incidence and risk factors of low back pain (LBP) in patients with lumbar degenerative disease after single-level oblique lateral interbody fusion (OLIF). METHODS: We retrospectively reviewed 120 lumbar degenerative disease patients who underwent single-level OLIF. We compared preoperative and postoperative radiographic parameters, including segmental lordosis (SL), lumbar lordosis (LL), disk height (DH), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), and C7-sagittal vertical axis (SVA). Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) scores and visual analog scale (VAS) scores for back and leg pain. All patients were followed up for at least 2 years. RESULTS: Thirty-eight patients had postoperative LBP (VAS score for back pain ≥3; LBP group); the remaining 82 patients were in the non-LBP group. Age (P = 0.082), gender (P = 0.425), body mass index (P = 0.138), diagnosis (degenerative spondylolisthesis vs. lumbar spinal stenosis; P = 0.529), surgical level (P = 0.651), blood loss (P = 0.889), and operative time (P = 0.731) did not differ between the groups. In both groups, the ODI and VAS scores for back pain and leg pain significantly improved at the final follow-up compared with the preoperative scores (P = 0.003). Except for the VAS score for back pain (P = 0.000), none of the scores significantly differed between the two groups at the final follow-up (P > 0.05). In the non-LBP group, LL, SL, DH, TK, and SS significantly improved, while PT and C7-SVA significantly decreased at the final follow-up as compared with the preoperative values. In both groups, DH significantly improved postoperatively, with no significant between-group difference (P = 0.325). At the final follow-up, LL, PI-LL mismatch, PT, and C7-SVA showed significantly greater improvement in the non-LBP group than in the LBP group (P < 0.05). Multivariate analysis identified PT, PI-LL mismatch, and C7-SVA as significant risk factors for LBP after OLIF. CONCLUSION: OLIF for single-level lumbar degenerative disease had satisfactory clinical outcomes. PT, PI-LL mismatch, and C7-SVA were significant risk factors for postoperative LBP. Patients with appropriately decreased PT, improved C7-SVA, and PI-LL match experienced less LBP.

The Effect of Surgical Decompression and Fusion on Functional Balance in Patients With Degenerative Lumbar Spondylolisthesis.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To quantify the effect of lumbar decompression and fusion surgery on balance and stability in patients with degenerative lumbar spondylolisthesis (DLS) and compare them to controls. SUMMARY OF BACKGROUND DATA: DLS is a condition in which one vertebra subluxates relative to an adjacent vertebra in the absence of a disruption in the neural arch. While the existing literature demonstrates that decompression and fusion can successfully alleviate pain and reduce disability in patients with DLS, no studies to date have used quantitative dynamic testing to determine the effect of surgery on cone of economy (CoE) measures in this patient population. METHODS: Forty-five DLS patients performed a series of functional balance tests a week before and 3 months after surgery and were compared to 28 controls. The outcome measures included range of sway (RoS) and total sway for the center of mass (CoM) and head in the sagittal, coronal, and axial planes, along with leg and back Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Fear/Avoidance Behavior Questionnaire (FABQ), Tampa Scale of Kinesophobia (TSK), and Demoralization scale. RESULTS: RoS for the CoM (P < 0.005) and head (P < 0.017) decreased in all planes postoperatively. Reductions in CoM (P = 0.001) and head total sway (P = 0.001) were also observed after surgery. Furthermore, patients with DLS reported strong improvements in VAS low back (P = 0.001), VAS leg (P = 0.001), ODI (P = 0.001), FABQ Physical (P = 0.003), TSK (P = 0.001), and demoralization (P = 0.044) with surgical intervention. Although total sway was reduced after surgery, it did not return to the level of normal controls as demonstrated with more total sway of their CoM (P = 0.002) and head (P = 0.001) as well as more sagittal head RoS (P = 0.048). CONCLUSION: This study confirms that surgical intervention for degenerative spondylolisthesis is effective at reducing disability, back and leg pain, demoralization, kinesiophobia, and fear-avoidance beliefs related to physical activity in patients with DLS. Furthermore, such patients exhibit a significantly more stable stance after surgery. However, balance parameters did not completely normalize by 3 months postoperatively. LEVEL OF EVIDENCE: 3.

Morphologic Changes of Intervertebral Foramen After Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Radiographic and Clinical Study.

OBJECTIVE: We aimed to investigate the morphologic changes in the intervertebral foramen after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), and analyze the necessity of routinely performing contralateral intervertebral foraminal decompression in degenerative lumbar spondylolisthesis cases with bilateral symptoms. METHODS: 72 single-level degenerative lumbar spndylolisthesis patients with bilateral symptoms were included, all of whom underwent unilateral approach MIS-TLIF. Preoperative and postoperative foraminal height (FH), foraminal width (FW), disc height (DH), distance from existing nerve root to upper edge of lower pedicle (RTP), and contralateral side spinal canal area (CSCA) were measured at surgical and contralateral side. Clinical outcomes were evaluated using the visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association score. RESULTS: The preoperative values are comparable between operative and contralateral sides (P > .05). The postoperative values for FH on operative and contralateral sides were 16.23±2.48 mm and 16.10±2.42 mm, for FW were 11.36±2.58 mm and 11.31±2.71 mm, for IH were 8.18±1.58 mm and 8.42±1.54 mm, for RTP were 8.58±1.26 mm and 9.14±1.77 mm, and the CSCA of the spinal canal on the contralateral side were 211.59±48.12 mm², respectively. The difference between these was also not statistically significant (P > .05). The values increased significantly on the surgical and contralateral side (P < .05). The visual analog scale for low-back and leg pain, Japanese Orthopaedic Association, and Oswestry Disability Index improved significantly at 2-year follow-up. CONCLUSIONS: Unilateral MIS-TLIF can effectively improve contralateral FH, DH, FW, RTP, and CSCA. It is not necessary to routinely perform contralateral intervertebral foramen decompression in degenerative lumbar spondylolisthesis with bilateral symptoms when symptoms are mild on one side.

A new lever reduction technique for the surgical treatment of elderly patients with lumbar degenerative Spondylolisthesis.

BACKGROUND: Proper reduction method for Lumbar degenerative spondylolisthesis (LDS) is still controversial. The aim of this study was to determine the safety and effectiveness of lever reduction combined with traditional elevating-pull reduction technique for the treatment of elderly patients with LDS. METHODS: From May 2015 to December 2017, 142 elderly patients (≥65 years) diagnosed with LDS were enrolled in this study with a mean follow-up of 25.42 ± 8.31 months. All patients were operated using lever reduction combined with traditional elevating-pull reduction technique. Patient age, sex, body mass index, bone mineral density, preoperative comorbidities, surgical duration, blood loss, and surgical complications were collected form patient charts. Clinical data as visual analog scale (VAS), Oswestry Disability Index (ODI), and 36-Item Short Form Health Survey (SF-36) were collected preoperatively, 1 month postoperatively, and at the final follow-up. Radiographic evaluation included slip percentage, slip angle (SA), lumbar lordosis (LL), and fusion status. RESULTS: The clinical parameters of VASback, VASleg, ODI, and SF-36 had significantly improved at both follow-ups after surgery. A significant improvement was indicated for slippage reduction at both follow-ups, showing no significant correction loss after surgery. SA significantly increased after surgery and was well maintained at the final follow-up. LL was not affected by the surgery. At the final follow-up, complete fusion was obtained in 121 patients (85.2%) and partial fusion in 21 (14.8%). Revision surgery was performed for one patient. Screw loosening was observed in 3 (2.11%) cases. No nerve root injury or adjacent segment disease was observed. CONCLUSIONS: This new lever reduction combined with traditional elevating-pull reduction technique for the surgical treatment of elderly patients with LDS is both safe and effective. Satisfactory correction and fusion rates were achieved with acceptable correction loss and reduction-related complications.

Primary pain generator identification by CT-SPECT in patients with degenerative spinal disease.

OBJECTIVE: Axial spinal pain generators are difficult to identify using current diagnostic modalities. Merging CT with SPECT (CT-SPECT) scans allows for accurate identification of areas with increased osteoblastic activity, which may reflect pain generators. In this study, the authors aimed to evaluate the degree of pain improvement in patients who underwent surgery, addressing primary pain generators identified by CT-SPECT. METHODS: The authors retrospectively reviewed all patients with chronic axial spine pain who underwent diagnostic CT-SPECT at their institution and analyzed pain improvement in those who underwent surgical treatment in order to determine whether CT-SPECT correctly identified the primary pain generator. RESULTS: A total of 315 patients underwent diagnostic CT-SPECT between January 2014 and August 2018. Forty-eight patients underwent either cervical or lumbar fusion; there were 26 women (16 cervical, 10 lumbar) and 22 men (9 cervical, 13 lumbar). The overall axial spinal pain, as assessed through self-reporting of visual analog scale scores at 6 months postoperatively, improved from 9.04 ± 1.4 to 4.34 ± 2.3 (p = 0.026), with cervical fusion patients improving from 8.8 ± 1.8 to 3.92 ± 2.2 (p = 0.019) and lumbar fusion patients improving from 9.35 ± 0.7 to 4.87 ± 2.3 (p = 0.008). CONCLUSIONS: CT-SPECT may offer a diagnostic advantage over current imaging modalities in identifying the primary pain generator in patients with axial spinal pain.

Global sagittal spinal alignment in patients with degenerative low-grade lumbar spondylolisthesis.

PURPOSE: Global sagittal spinal alignment undergoes changes on the basis of sagittal malalignment (trunk inclined forward) in natural degenerative progression. We hypothesized that this change would associate with the disease state of the degenerative lumbar spondylolisthesis (DS). This study aimed to evaluate the global sagittal spinal alignment of low-grade DS by classifying in accordance with sagittal vertical axis (SVA). METHODS: The DS group was classified into three types according to the adult spinal deformity classification: type 1, SVA < 40 mm; type 2, 40 mm ≤ SVA < 95 mm; and type 3, 95 mm ≤ SVA. Age and sagittal spinal parameters (thoracic kyphosis, lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI)) were compared among three types. RESULTS: There were statistically significant differences in age, LL, PI, and PT among the three types. In comparison between two types, there was a statistically significant difference between type 1 and type 2 and between type 1 and type 3, but not between type 2 and type 3 in these parameters. PI tended to increase as the type increases. Furthermore, there was significant difference between types 1 and 3. CONCLUSION: We evaluated the features of the DS types classified by sagittal alignment. Large PI is one of the risk factors for SVA deterioration of DS. PI may be involved in the onset and progression of DS.

Patients undergoing surgery for lumbar spinal stenosis experience unique courses of pain and disability: A group-based trajectory analysis.

OBJECTIVE: Identify patient subgroups defined by trajectories of pain and disability following surgery for degenerative lumbar spinal stenosis, and investigate the construct validity of the subgroups by evaluating for meaningful differences in clinical outcomes. METHODS: We recruited patients with degenerative lumbar spinal stenosis from 13 surgical spine centers who were deemed to be surgical candidates. Study outcomes (leg and back pain numeric rating scales, modified Oswestry disability index) were measured before surgery, and after 3, 12, and 24 months. Group-based trajectory models were developed to identify trajectory subgroups for leg pain, back pain, and pain-related disability. We examined for differences in the proportion of patients achieving minimum clinically important change in pain and disability (30%) and clinical success (50% reduction in disability or Oswestry score ≤22) 12 months from surgery. RESULTS: Data from 548 patients (mean[SD] age = 66.7[9.1] years; 46% female) were included. The models estimated 3 unique trajectories for leg pain (excellent outcome = 14.4%, good outcome = 49.5%, poor outcome = 36.1%), back pain (excellent outcome = 13.1%, good outcome = 45.0%, poor outcome = 41.9%), and disability (excellent outcome = 30.8%, fair outcome = 40.1%, poor outcome = 29.1%). The construct validity of the trajectory subgroups was confirmed by between-trajectory group differences in the proportion of patients meeting thresholds for minimum clinically important change and clinical success after 12 postoperative months (p < .001). CONCLUSION: Subgroups of patients with degenerative lumbar spinal stenosis can be identified by their trajectories of pain and disability following surgery. Although most patients experienced important reductions in pain and disability, 29% to 42% of patients were classified as members of an outcome trajectory subgroup that experienced little to no benefit from surgery. These findings may inform appropriate expectation setting for patients and clinicians and highlight the need for better methods of treatment selection for patients with degenerative lumbar spinal stenosis.

The correlation analysis between sagittal alignment and cross-sectional area of paraspinal muscle in patients with lumbar spinal stenosis and degenerative spondylolisthesis.

BACKGROUND: The relationship between spinal alignment and skeletal muscle mass (SMM) has attracted attention in recent years. Sagittal alignment is known to deteriorate with age, but it is not known whether this is related to paraspinal muscles. Therefore, the purpose of this study is to elucidate the role of the multifidus (MF) and psoas major (PS) muscles in maintaining global spinal alignment in patients with lumbar spinal stenosis (LSS) and/or degenerative spondylolisthesis (DS), and to analyze whether each muscles' cross-sectional area (CSA) correlates with whole-body SMM using bioimpedance analysis (BIA). METHODS: We retrospectively evaluated 140 patients who were hospitalized for surgery to treat LSS and/or DS. Spinal alignment, CSA of spinal muscles, and body composition parameters were measured from full-length standing whole-spine radiography, MRI, and BIA before surgery. The following standard measurements were obtained from radiographs: sagittal balance (C7-SVA), cervical lordosis (CL; C2-C7), lumbar lordosis (LL; L1-S1), thoracic kyphosis (TK; T5-T12), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). RESULTS: The average PS CSA (AveCSA) was highest at L4-L5, whereas MF AveCSA was highest at L5-S1. Paraspinal muscle CSAs were greater in males than in females. There was no statistically significant difference between the left and right CSA for either MF or PS. Correlation coefficient showed strong correlations between the PS AveCSA (L4-L5) and whole body SMM (r = 0.739). Correlation coefficient analysis also showed weak correlation between SMM and PT (r = - 0.184). Furthermore, PS AveCSA (L4-L5) correlated with the PT (r = - 0.183) and age (r = - 0.156), while PT correlated with the whole body SMM (r = - 0.184) but not with age. CONCLUSIONS: Whole body SMM showed correlation with PS AvCSA (L4-L5) and with PT among the spinal parameters, which was the same result in MF AvCSA (L4-L5). These findings suggest that the posterior inclination of the pelvis may be correlated with paraspinal muscle area rather than age.

Concomitant low-grade isthmic L5-spondylolisthesis does not affect the course of adolescent idiopathic scoliosis.

BACKGROUND: Scoliosis with spondylolisthesis was described in 4.4-48%. No information on clinical impact or outcome is available. PURPOSE: To determine the prevalence of this pathology and to investigate its affect on the course of adolescent idiopathic scoliosis (AIS). METHODS: A retrospective comparative study using patients' records, radiographs, the national inpatient registry, and Patient-rated outcome measures (PROM): Oswestry disability index (ODI), modif.SRS-24 questionnaire, WHO-Quality of life index (WHOQoL), Numerical rating scale (NRS) for pain. Clinical follow-up time was 4.4 (4.3) years, and follow-up rate was 95%. PROM follow-up time 26.4 (2.8) years χ2 statistics and t-tests were applied. Significance threshold was set at P < 0.05. RESULTS: Out of 1531 consecutive Caucasian AIS patients, aged 13.9 (1.8) years, primary curve 29.2 (11.5) drs., 120 (7.8%) had low-grade isthmic L5-slip of mean 15.0 (8.3)% (Study group = S). The distribution of the curve types in the study group was comparable to the remaining 1411 patients with AIS only. In comparison with a pair-matched control group (C) at admission, back pain interfering with activities of daily living had 4.2% of the study group and 1.7% of the control group, at clinical follow-up 2.6/4.2% resp. (n.s.). Between groups S/C, there was no significant difference concerning scoliosis treatment: observation 38.3/45.8%, bracing 48.3/46.6%, surgery 10.8/10.2%. Results of treatment were equal in both groups. Long-term outcomes (ODI, SRS-24, WHOQoL, NRS-back/leg pain) were comparable. CONCLUSIONS: The prevalence of low-grade isthmic L5-spondylolisthesis in AIS patients was 7.8%. The presence of low-grade isthmic spondylolisthesis did not influence the curve type of AIS nor did it affect the course or long-term outcome. These slides can be retrieved under Electronic Supplementary Material.

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.

Short Lumbosacral Decompression Plus Fixation Does Not Change the Spinopelvic Balance on Patients With Moderate Degenerative Spondylolisthesis and Associated Spinal Stenosis.

STUDY DESIGN: A retrospective cohort study. OBJECTIVES: To investigate whether decompression plus short segment lumbosacral fixation changes the sagittal baseline spinopelvic parameters in patients with moderate degenerative spondylolisthesis (DS) and associated degenerative lumbar spinal stenosis (DLSS). SUMMARY OF BACKGROUND DATA: Spinal decompression and fusion are commonly performed in DS with associated DLSS. Spinopelvic alignment after surgery for DS is an important research topic. The effect of short lumbosacral instrumented fusion on the global sagittal spinal balance has not been sufficiently studied. METHODS: Thirty-four consecutive adult patients (21 women, 13 men) aged 62 ± 11 years with balanced spines [sagittal vertical axis (SVA) ≤ 40 mm] received decompression and two to three vertebrae fixation plus fusion for DS grades I and II, associated with symptomatic DLSS. Age, gender, number of segments fused, posterolateral fusion (PLF) versus PLF plus posterior lumbar interbody fusion (PLIF) and segmental lordosis (SL) in the free segment above instrumentation were studied for a minimum follow-up of 60 months. The roentgenographic variables measured are T12-S1 lumbar lordosis (LL), SVA, sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), SL, and anterior (ADH) and posterior disc height (PDH) in the suprajacent free lumbar segment. Clinical outcomes were assessed with visual analog scale and Oswestry Disability Index. RESULTS: SVA significantly (p = .05) decreased postoperatively but returned to the baseline value at the final observation. Younger individuals (≤59 years) stood with greater SS (p = .036) 6 months postoperatively and with less SVA in all 3 periods of observation (p = .013, .046, and .024) than their older (>59 years) counterparts. Patients with monosegmental stenosis showed on baseline less SVA (p = .028), PT (p = .031), and PI (p = .004) than their two-segmental stenosis counterparts. PI preoperatively to the last evaluation was significantly smaller in the patients who received 360° fusion (p<.016). CONCLUSIONS: Short lumbosacral fixation does not significantly change the preoperative sagittal spinopelvic balance in adult patients with preoperatively balanced spines who have DS and DLSS. LEVEL OF EVIDENCE: Level III.

Expectations for Postoperative Improvement in Health-Related Quality of Life in Young Patients With Lumbosacral Spondylolisthesis: A Prospective Cohort Study.

STUDY DESIGN: Prospective multicenter study of the changes in Scoliosis Research Society Outcome Questionaire 22 (SRS-22) scores for 78 patients younger than 25 years old surgically treated for lumbosacral spondylolisthesis OBJECTIVE.: Report the change of health-related quality of life (HRQOL) in patients younger than 25 years after surgical treatment of lumbosacral spondylolisthesis. SUMMARY OF BACKGROUND DATA: There is a paucity of data with regard to the influence of surgical treatment on the HRQOL of patients with lumbosacral spondylolisthesis. Large prospective studies are needed to clearly define the benefits of surgery in the young patient population. METHODS: A prospective multicenter cohort of 78 patients younger than 25 years (14.8 ±â€Š2.9, range: 7.9-23.6 yr) undergoing posterior fusion for lumbosacral spondylolisthesis were enrolled. There were 17 patients with low-grade (<50%) and 61 with high-grade (≥50%) slips. SRS-22 scores calculated before surgery and after 2 years of follow-up were compared for all patients using two-tailed paired t tests. Subanalyses for low- and high-grade patients were done using two-tailed Wilcoxon signed ranked and paired t tests, respectively. The level of significance was set at 0.05. RESULTS: HRQOL was significantly improved 2 years after surgery for all domains and for the total score of the SRS-22 questionnaire. The individual total score was improved in 66 patients (85%), and 52 patients (67%) improved by at least 0.5 point. All domains and the total score of the SRS-22 questionnaire were significantly improved for high-grade patients, whereas only pain, function, and total score were improved for low-grade patients. CONCLUSION: This is the largest study comparing the HRQOL before and after surgery in young patients with low- and high-grade lumbosacral spondylolisthesis. HRQOL significantly improves after surgery for the majority of patients, especially for high-grade patients. This study helps clinicians to better counsel patients with regard to the benefits of surgery for lumbosacral spondylolisthesis. LEVEL OF EVIDENCE: 2.