The relevance of sacral and sacro-pelvic morphology in developmental lumbosacral spondylolisthesis: are they equally important?

Effects of Cycling on Spine: A Case-Control Study Using a 3D Scanning Method

BACKGROUND

Few studies have investigated the effects of adopting a specific and prolonged posture on cyclists. This study aimed to evaluate the upright spine in a sample of recreational cyclists and compare it with a sample of non-cyclists, though still athletes, through a 3D scanning method.

METHODS

Forty-eight participants were enrolled in this observational study. The sample consisted of 25 cyclists for the cycling group and 23 non-cyclist athletes for the control group. The Spine3D device (Sensor Medica, Guidonia Montecelio, Rome, Italy) was used to evaluate the spine of the participants in both groups.

RESULTS

The results showed significantly greater spine inclination in the cycling group compared to the control group (p < 0.01). Furthermore, there was a significant decrease in lumbar lordosis in the cycling group compared to the control group (p < 0.01).

CONCLUSIONS

This case-control study raises the possibility that the onset of lower back pain in cyclists may be due to a reduction in lumbar lordosis. Furthermore, this study demonstrated that the Spine3D device can be used in sports to monitor the spine of athletes to prevent and reduce musculoskeletal deficits.

Impact of Individual Spinopelvic Anatomy on the Localization and Severity of Symptomatic Isthmic Spondylolisthesis

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVES

Isthmic spondylolisthesis (iSPL) occurs most commonly in L5/S1 and L4/5. This study investigates the association between spinopelvic anatomy and the pathogenesis of iSPL.

METHODS

Spinopelvic parameters as well as severity of slip grade were measured in sagittal spine radiographs of symptomatic patients with iSPL in segments L4/5 and L5/S1. Means were calculated and differences between both groups were analyzed. A correlation between the analyzed parameters and degree of slippage was performed.

RESULTS

We included 73 subjects in this study; 11 in L4/5 group and 62 in L5/S1 group. Pelvic anatomy significantly differed between L4/5 and L5/S1 iSPL (Pelvic Incidence (PI) 54.8° vs 66.3°, P value = .006; Pelvic Radius (PR) 124.4 mm vs 137.4 mm; P value = .005 and Sacral Table Angle (STA) 101.0° vs 92.2°, P value < .001). The relative degree of slippage was significantly higher in the L5/S1 group (L4/5 29.1% vs L5/S1 40.1%, P value .022). We also observed a significant correlation between pelvic anatomy and the severity of the slip in iSPL at the L5/S1 level.

CONCLUSIONS

Pelvic parameters PI and STA play an important role concerning the level of occurrence and severity of iSPL. Spinopelvic anatomy determines the pathogenesis of iSPL.

The correlation of sacral table angle to spinopelvic sagittal alignment in healthy adults

BACKGROUND

The sacrum plays an important role in sagittal balance of the spine, whereas the exact association between sacral parameters, specifically the sacral table angle (STA) and spinopelvic parameters has been only scarcely assessed. It aims to investigate the correlations between the sacral parameters and spinopelvic sagittal alignment parameters in healthy adults.

METHODS

A cohort of 142 Northern Chinese healthy adults between 18 and 45 years old were recruited between April 2019 and March 2021. Full-spine standing X-ray films were performed for every volunteer. The sacral parameters were measured: sacral table angle (STA), sacral inclination (SI) and sacral slope (SS). The spinopelvic sagittal alignment parameters included: pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis and the apex of lumbar lordosis (LLA). The correlations analysis, as well as the linear regression analysis, were performed between STA, SI and the spinopelvic parameters.

RESULTS

An equation 'STA = SI + 90 - SS' was revealed to represent the interrelationships between STA, SI and SS. STA was statistically correlated with PI (r_s = - 0.693), PT (r_s = - 0.342), SS (r_s = - 0.530), LL (r_s = 0.454), and LLA (r_s = 0.438). SI correlated with STA (r_s = 0.329), PT (r_s =  - 0.562), SS (r_s =  - 0.612) and LL (r_s = 0.476). Simple linear regression analysis also verified the correlation between STA and PI (y = - 1.047x + 149.4), SS (y = - 0.631x + 96.9), LL (y = 0.660x - 117.7), LLA (y = 0.032x + 0.535), and SI (y = 0.359x + 8.23).

CONCLUSION

The equation 'STA = SI + 90 - SS' indicates the exact geometric relationship between STA, SI and SS. The sacral parameters, both STA and SI, correlate to the spinopelvic sagittal alignment parameters in healthy adults. The linear regression analysis results also give predictive models for spinopelvic sagittal alignment parameters based on the invariant parameter STA, which are helpful for surgeons in designing an ideal therapeutic plan.

Spondylolysis

Spondylolysis is a bony defect of the pars interarticularis and most often results from repetitive stress. Although spondylolysis is usually asymptomatic, symptomatic spondylolysis is the most common cause of identifiable back pain in children and adolescent athletes. A thorough history and physical exam, as well as appropriate imaging studies are helpful in diagnosis. General first-ine therapy for spondylolysis is conservative and consists of rest from sports, core strengthening, as well as spinal bracing. Patients who have failed conservative therapy may consider surgical repair. This article aims to review the epidemiology, pathophysiology, presentation, and treatment options of spondylolysis.

Sacral anatomical parameters varies in different Roussouly sagittal shapes as well as their relations to lumbopelvic parameters

PURPOSE

To study the normal variations in sacral anatomical parameters in different Roussouly sagittal shapes and the association between sacral anatomical parameters and lumbopelvic parameters in healthy adults.

METHODS

A cohort of 239 healthy volunteers between 18 and 45 years old was enrolled in this study. A full-spine, standing X-ray was taken for each volunteer. The following parameters were measured: the sacral table angle (STA), sacral kyphosis (SK), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and lumbar lordosis apex (LLA). Two hundred and thirty-nine volunteers were classified into five groups according to the Roussouly classification. The differences in sagittal parameters among the five groups were evaluated by one-way analysis of variance. The correlations between lumbopelvic parameters and sacral anatomical parameters were analyzed, and simple linear regressions were simultaneously constructed.

RESULT

The sacral anatomical parameters vary in different Roussouly sagittal shapes. Correlation analysis revealed that the significant correlations between sacral anatomical parameters and lumbopelvic parameters. The STA correlated with PI (r = -.690, P <.001), PT (r = -.216, P = .001), SS (r = -.631, P <.001), LL (r = -.491, P <.001), and LLA (r = 0.515, P <.001). The corresponding regression formulae were as follows: PI = -0.991*STA + 143(R 2 = .476), LL = 0.870*STA-135.1(R 2 = .242), and LLA = 0.039*STA -0.087(R 2 = .265). The SK correlated with PI (r = .471, P <.001), PT (r = .445, P = .001), SS (r = .533, P <.001), LL (r = .438, P <.001), and the LLA (r = -.265, P <.001). The corresponding regression formulae were as follows: PI = 0.38*SK + 27.22(R 2 = .396), LL = -0.35*SK - 35.99(R 2 = .192), and LLA = -0.01*SK + 4.25(R 2 = .201).

CONCLUSIONS

The sacral anatomical parameters vary in different Roussouly sagittal shapes and have strong correlations with lumbopelvic parameters, which demonstrates that the specific lumbar shape can be affected by the sacral morphology. Moreover, the predictive models of lumbopelvic parameters based on SK and STA have been provided, which demonstrates constant sacral anatomical parameters could serve as good supplementary index of PI to predict ideal lumbar parameters.

Sacropelvic Parameters and L5 Spondylolysis: Computed Tomography Analysis

Study Design

Retrospective analysis of computed tomography scans.

Purpose

This study aims to determine the association of sagittal sacropelvic parameters with L5 spondylolysis.

Overview of Literature

The association of increased pelvic incidence (PI) and decreased sacral table angle (STA) with spondylolysis has been reported, but no study has simultaneously analyzed multiple sacropelvic variables to compare their association.

Methods

In this study, computed tomography scans obtained to assess major trauma in patients aged >16 years were analyzed. Scans meeting one of the following criteria were excluded: abnormal anatomy, previous spine or hip/pelvis surgery, or spinal pathology, including deformity, infection, tumor, or trauma. sacral anatomic orientation (SAO), PI, pelvic thickness (PTH), femoro-sacral posterior angle (FSPA), STA, and sacral kyphosis (SK) were measured.

Results

Overall, 202 scans were analyzed: 25 with L5 spondylolysis and 177 normal. Among the groups, a significant difference was observed in SAO (43.3° vs. 51.6°), PI (61.7° vs. 49.8°), STA (95.4° vs. 101.8°), and SK (31.0° vs. 23.7°). Based on the logistic regression analysis, only PI (odds ratio [OR], 1.074; 95% CI, 1.026–1.124) and STA (OR, 0.822; 95% CI, 0.734–0.920) remained significant predictors for the presence of spondylolysis. In the spondylolysis group, PI correlated significantly with PTH (r=−0.589), FSPA (r=0.880), and SK (r=0.576), whereas in the normal group, PI correlated significantly with FSPA (r=0.781) and SK (r=0.728).

Conclusions

By simultaneously assessing multiple sacropelvic parameters, we associated increasing PI with L5 spondylolysis. Decreasing STA, which likely represents a chronic remodeling secondary to spondylolysis, was also associated with increased risk. Back pain in an adolescent or young adult with high PI or low STA should raise suspicion of a possible occult spondylolysis.

Comparison of the sacral table angles by progression stage of lumbar spondylolysis

STUDY DESIGN

Retrospective study.

OBJECTIVES

The purpose of this study was to investigate sacral table angle (STA) values in early-stage spondylolysis. Several studies suggested that the STA of patients with L5 spondylolysis or spondylolisthesis was significantly lower than that of healthy controls. Separation of the pars interarticularis creates shear stress between the upper sacral end plate and L5 vertebra. This was considered the cause of low STA in patients with spondylolysis or spondylolisthesis. However, if a low STA value is obtained in the early stage of L5 spondylolysis, it suggests that low STA does not result in the remodeling of the sacral end plate.

METHODS

Patients with L5 spondylolysis and those with low back pain without pars defect were retrospectively identified from a hospital database in 2014-2016. Pars defect of the spondylolysis was classified into three categories based on CT and MRI results: early, progressive, or terminal stage. The STA difference between groups was calculated using one-way analysis of variance and Scheffe F test, which were used for post hoc testing.

RESULTS

A total of 84 cases of L5 spondylolysis and 70 cases of low back pain were identified. No significant difference was found between the STAs of the early- or progressive-stage spondylolysis and the terminal-stage L5 spondylolysis and low back pain patients. The STA of the terminal-stage L5 spondylolysis was significantly lower than that of low back pain patients.

CONCLUSIONS

In conclusion, patients with early- or progressive-stage spondylolysis do not have low STA. Low STA is seen only in patients with terminal-stage spondylolysis, suggesting that low STA is associated with remodeling changes in response to shear force after onset of spondylolysis. STA value might not important as a prognostic parameter about development of the spondylolysis.

LEVEL OF EVIDENCE

Level IV.

Current Evidence Regarding the Diagnostic Methods for Pediatric Lumbar Spondylolisthesis: A Report From the Scoliosis Research Society Evidence Based Medicine Committee

STUDY DESIGN

Structured literature review.

OBJECTIVES

The Scoliosis Research Society (SRS) requested an assessment of the current state of peer-reviewed evidence regarding pediatric lumbar spondylolisthesis with the goal of identifying what is known and what gaps remain in further understanding the diagnostic methods for pediatric spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Spondylolisthesis in the lumbar spine is common among children and adolescents and no formal synthesis of the published literature regarding diagnostic methods has been previously performed.

METHODS

A comprehensive literature search was performed. Abstracts were reviewed and data from included studies were analyzed by the committee. From 6600 initial citations with abstract, 663 articles underwent full-text review. The best available evidence for the clinical questions regarding diagnostic methods was provided by 26 included studies. Six of the studies were graded as Level III (retrospective comparative), and represent the current best available evidence whereas 20 of the studies were graded as Level IV (retrospective case series) evidence. No Level V (expert opinion) studies were included in the final list. None of the studies were graded as Level I or Level II.

RESULTS

Plain radiography is the workhorse imaging modality for diagnosing spondylolisthesis. No association between radiologic grade of spondylolisthesis and clinical presentation were noted; however, grade III and IV slips more often required surgery, and increasing slip angles were associated with worse baseline outcome scores. There is Level III evidence that the Meyerding grade appears to be more accurate for measuring slip percentage whereas the Lonstein Slip angle and Dubousset Lumbosacral Kyphosis angles are the best for measuring lumbosacral kyphosis in spondylolisthesis. In addition, higher sacral table index, pelvic incidence, sacral slope, and lower sacral table angle were associated with spondylolisthesis. True incidence could not be determined by the current literature available. However, studies in adolescent athletes demonstrated an incidence of 6% to 7% across studies.

CONCLUSIONS

The current "best available" evidence to guide the diagnosis and characterization of pediatric spondylolisthesis is presented. Future studies are needed to provide more high-quality evidence to answer these clinically relevant questions.

LEVEL OF EVIDENCE

Level III, review of Level III studies.

Association between spondylolisthesis and L5 fracture in patients with Osteogenesis Imperfecta

PURPOSE

To investigate if an association between spondylolisthesis and L5 fracture occurs in patients affected by Osteogenesis Imperfecta (O.I.).

METHODS

Anteroposterior and lateral radiograms were performed on the sample (38 O.I. patients, of whom 19 presenting listhesis); on imaging studies spondylolisthesis was quantified according to the Meyerding classification. Genant's semiquantitative classification was applied on lateral view to evaluate the L5 fractures; skeleton spinal morphometry (MXA) was carried out on the same images to collect quantitative data comparable and superimposable to Genant's classification. The gathered information were analyzed through statistical tests (O.R., χ ² test, Fisher's test, Pearson's correlation coefficient).

RESULTS

The prevalence of L5 fractures is 73.7 % in O.I. patients with spondylolisthesis and their risk of experiencing such a fracture is twice than O.I. patients without listhesis (OR 2.04). Pearson's χ ² test demonstrates an association between L5 spondylolisthesis and L5 fracture, especially with moderate, posterior fractures (p = 0.017) and primarily in patients affected by type IV O.I.

CONCLUSIONS

Spondylolisthesis represents a risk factor for the development of more severe and biconcave/posterior type fractures of L5 in patients suffering from O.I., especially in type IV. This fits the hypothesis that the anterior sliding of the soma of L5 alters the dynamics of action of the load forces, localizing them on the central and posterior heights that become the focus of the stress due to movement of flexion-extension and twisting of the spine. As a result, there is greater probability of developing an important subsidence of the central and posterior walls of the soma.