Differences of Sagittal Lumbosacral Parameters between Patients with Lumbar Spondylolysis and Normal Adults

The triadic relationship between spinal posture, loading, and degeneration

Introduction

Degenerative changes in the lumbar spine may affect many structures, among them the intervertebral discs and the facet joints. The individual load distribution within the spine linked to posture and mass distribution is a probable cause of disease. This study had a dual aim: first, to systematically summarize previously reported associations between sagittal balance parameters and the occurrence of lumbar spine degeneration. Second, to complement these insights with additional biomechanical findings meant to elucidate the link between spine load and alignment as well as selected demographic descriptors.

Methods

A systematic literature search was performed on PubMed to identify clinical studies that quantified the association between spinal alignment and the occurrence of disc herniation, disc degeneration, facet joint degeneration, and spondylolisthesis. Further, a previously published musculoskeletal model was used to link sagittal spinal alignment and subject characteristics to joint loading within the lumbar spine for a cohort of 144 subjects.

Results

The literature review yielded 49 publications evaluating the relationship between spinal alignment and the occurrence of pathologies in the lumbar spine. The results indicate that a straight spine might negatively affect the health status of the intervertebral disc, likely because of a lack of damping and associated high compressive loads. These loads further show a major dependence on body weight. On the other hand, facet degeneration and spondylolisthesis may be linked to higher anterior-posterior shear forces acting on the relevant spinal structures because of a generally more sagittally curved spine. A straight lumbar spine is more likely to stress the disc, whereas highly curved spines with a high pelvic incidence are more likely to stress the posterior structures. The biggest influencing factors on the resulting force and consequently potentially the wear of the anatomical structures are the intervertebral inclination from an anatomical point of view and the weight from a demographic point of view.

Discussion

Information concerning spinal loading resulting from spinal alignment and body descriptors could impact both conservative treatment and operative planning for patients afflicted by spine disease through targeted changes in posture.

Risk Factors for Nonunion After Nonoperative Treatment for Pediatric Lumbar Spondylolysis: A Retrospective Case-Control Study

BACKGROUND

Pediatric lumbar spondylolysis, a stress fracture of the lumbar spine, frequently affects young athletes, and nonoperative treatment is often the first choice of management. Because the union rate in lumbar spondylolysis is lower than that in general fatigue fractures, identifying risk factors for nonunion is essential for optimizing treatment.

PURPOSE

To determine the risk factors for nonunion after nonoperative treatment of acute pediatric lumbar spondylolysis through multivariate analysis.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

We analyzed 574 pediatric patients (mean age, 14.3 ± 1.9 years) with lumbar spondylolysis who underwent nonoperative treatment between 2015 and 2022. Nonoperative treatment included the elimination of sports activities, bracing, and weekly athletic rehabilitation, with follow-up computed tomography. Patient data, lesion characteristics, sports history, presence of spina bifida occulta at the lamina with a lesion or at the lumbosacral spine excluding the lesion level, and lumbosacral parameters were examined. Differences between the union and nonunion groups were investigated using multivariate analysis to determine the risk factors for nonunion.

RESULTS

Of the 574 patients, 81.7% achieved bone union. Multivariate analysis revealed that an L5 lesion and the progression of the main and contralateral lesion stages were significant independent risk factors for nonunion. An L5 lesion had a lower union rate than non-L5 lesions. As the main lesion progressed, the likelihood of nonunion increased significantly, and the progression of the contralateral lesion also showed a similar trend. Spina bifida occulta and lumbosacral parameters were not significant predictors of nonunion in this study.

CONCLUSION

We identified the L5 lesion level and the progression of the main and contralateral lesion stages as independent risk factors for nonunion in pediatric lumbar spondylolysis after nonoperative treatment. These findings aid in treatment decision-making. When bone union cannot be expected with nonoperative treatment, symptomatic treatment is required without prolonged external fixation and rest, and without aiming for bone union. Individualized treatment plans are crucial based on identified risk factors.

Effects of pilates exercises on radiographic lumbo-pelvic alignment and range of motion in non-specific low back pain patients

OBJECTIVES

To determine the effects of Pilates exercises on lumbo-pelvic alignment in non-specific low back pain (NSLBP) patients.

METHODS

Twenty-two patients (Male:7; Female:15) with NSLBP aged 20-65 years were recruited and classified based on a modified O'Sullivan's classification system into flexion pattern (FP) or active extension pattern (EP) groups. Oswestry Disability index (ODI), Roland-Morris Disability Questionnaire (RMDQ) as well as radiographic lumbar global range of motion (ROM) and lumbo-pelvic alignment were measured Pre- and immediately post-intervention and at 6- and 12-month. The intervention included supervised six-weeks Pilates program with 60 min per session and up to two sessions per week.

RESULTS

Lumbar lordosis, sacral slope and sacral inclination were found to be significantly different between the FP and EP groups based on the O'Sullivan's classification system. However, despite the significant changes in RMDQ (p = 0.001), no significant changes were found for any of the alignment parameters (p > 0.05) post intervention for both groups. For lumbar global ROM, a statistically significant change was observed for the EP group (p = 0.028) but not for the FP group (p = 0.249). No significant correlations were identified between any of the self-reported outcomes, radiographic alignment and ROM parameters.

CONCLUSIONS

Patients self-perceived long-term functional improvements based on responding to questionnaires after Pilates exercises were not reflected in significant changes in lumbo-pelvic alignment or lumbar ROM. This may be due to the current cohort demonstrating within normal ranges due to the lesser severity of their condition, but further research is needed for clarification.

Spondylolysis and Spondylolisthesis in Athletes

This article is an update on spondylolysis and spondylolisthesis in athletes, from diagnosis to treatment, based on our service experience and a literature review.

Relationship between Isokinetic Trunk Muscle Strength and Return to Sports Competition after Conservative Therapy in Fresh Cases of Lumbar Spondylolysis: A Retrospective Observational Study

This study aimed to clarify the relationship between isokinetic trunk muscle strength and return to sporting activities in fresh cases of lumbar spondylolysis treated with conservative therapy. Patients included a total of ten men (age: 13.5 ± 1.7) who were instructed by their attending physicians to stop exercising and who met the eligibility criteria. Isokinetic trunk muscle strength was measured immediately after exercising for the first time (First) and one month (1M). Flexion and extension and maximum torque/body weight ratio were significantly lower First compared to 1M at all angular velocities (p < 0.05). Maximum torque generation time was significantly lower for First at 120°/s and 180°/s than at 1M (p < 0.05). Correlations with the number of days to return to sports competition were detected at 60°/s for maximum torque generation time (p < 0.05, r = 0.65). Following conservative treatment for lumbar spondylolysis, it was considered necessary to focus on trunk flexion and extension muscle strength and contraction speed of trunk flexors at the beginning of the exercise period. It was suggested that trunk extension muscle strength in the extension range might be one of the critical factors for returning to sports.

Developing clinical algorithm for identifying acute lumbar spondylolysis in elementary school children - Classification and regression tree analysis

OBJECTIVES

To develop a clinical algorithm for classifying acute lumbar spondylolysis from nonspecific low back pain in elementary school-aged patients using the classification and regression tree analysis.

METHODS

Medical records of 73 school-aged patients diagnosed with acute lumbar spondylolysis or nonspecific low back pain were retrospectively reviewed. Fifty-eight patients were examined for establishing an algorithm and 15 were employed for testing its performance. The following data were retrieved: age, gender, school grades, days after symptom onset, history of low back pain, days of past low back pain, height, weight, body mass index, passive straight leg raise test results, hours per week spent on sports activities, existence of spina bifida, lumbar lordosis angle, and lumbosacral joint angle. Classification and regression tree analyses were performed 150 times using the bootstrap and aggregating method. Then, the results were integrated by majority vote, establishing an algorithm.

RESULTS

Lumbar lordosis angle, days after symptom onset, body mass index, and lumbosacral joint angle were the predictors for classifying those injuries.

CONCLUSION

The algorithm can be used to identify elementary school-aged children with low back pain requiring advanced imaging investigation, although a future study with a larger sample population is necessary for validating the algorithm.

Large Lumbar Lordosis Is a Risk Factor for Lumbar Spondylolysis in Patients with Adolescent Idiopathic Scoliosis

STUDY DESIGN

A retrospective, single-center, observational study.

OBJECTIVE

The aim of this study was to determine the prevalence and the characteristics of adolescent idiopathic scoliosis (AIS) patients with concomitant lumbar spondylolysis.

SUMMARY OF BACKGROUND DATA

The prevalence and features of lumbar spondylolysis in patients with AIS are unclear.

METHODS

We included 357 patients with AIS who underwent correction and fusion surgery. Preoperative computed tomography (CT) images were used to assess the existence of lumbar spondylolysis. Cobb angles of the curves, parameters of spinal alignment, Lenke classification, and the presence of low back pain were compared between patients with and without spondylolysis.

RESULTS

Of the patients included in the study, 6.1% had lumbar spondylolysis. They had significantly greater lumbar lordosis (LL) and sacral slope (SS) than those without lumbar spondylolysis. Logistic regression analyses and receiver-operating characteristic curves showed that LL was a significant risk factor (odds ratio: 1.059; 95% confidence interval: 1.018-1.103; P = 0.005) of associating lumbar spondylolysis with a cut off value of 56.5 degrees (area under the curve [AUC]: 0.689; sensitivity = 63.6%, specificity = 71.0%).

CONCLUSION

We should be vigilant for lumbar spondylolysis in AIS patients whose LL and SS are large, especially with LL larger than 56.5°.Level of Evidence: 3.

Identifying Acute Lumbar Spondylolysis in Young Athletes with Low Back Pain: Retrospective Classification and Regression Tree Analysis

STUDY DESIGN

Case-control study.

OBJECTIVE

The aim of this study was to establish an algorithm to distinguish acute lumbar spondylolysis (LS) from nonspecific low back pain (NSLBP) among patients in junior high school by classification and regression tree (CART) analysis.

SUMMARY OF BACKGROUND DATA

Rapid identification of acute LS is important because delayed diagnosis may result in pseudarthrosis in the pars interarticularis. To diagnose acute LS, magnetic resonance imaging (MRI) or computed tomography is necessary. However, not all adolescent patients with low back pain (LBP) can access these technologies. Therefore, a clinical algorithm that can detect acute LS is needed.

METHODS

The medical records of 223 junior high school-aged patients with diagnosed acute NSLBP or LS verified by MRI were reviewed. A total of 200 patients were examined for establishing the algorithm and 23 were employed for testing the performance of the algorithm. CART analysis was applied to establish the algorithm using the following data; age, sex, school grades, days after symptom onset, history of LBP, days of past LBP, height, passive straight leg raising test results, hours per week spent in sports activities, existence of spina bifida, lumbar lordosis angle, and lumbosacral joint angle. Sensitivity and specificity of the algorithm and the area under the ROC curve were calculated to assess algorithm performance.

RESULTS

The algorithm revealed that sex, days after symptom onset, days of past LBP, hours per week spent in sports activities, and existence of spina bifida were key predictors for identifying acute LS versus NSLBP. Algorithm sensitivity was 0.64, specificity was 0.92, and the area under the ROC curve was 0.79.

CONCLUSION

The algorithm can be used in clinical practice to distinguish acute LS from NSLBP in junior high school athletes, although referral to MRI may be necessary for definitive diagnosis considering the algorithm's sensitivity.Level of Evidence: 4.

Assessment of sagittal spinopelvic parameters in a Taiwanese population with spondylolysis by the EOS imaging system: a retrospective radiological analysis

Background

The impact of sagittal spinopelvic alignment on spondylolysis is well established in Caucasian populations. However, prior studies suggest that people from different ethnological backgrounds showed divergence, and a few studies that focused on Asian populations reported conflicting results. The aim of this study is to use the EOS imaging system to evaluate the spinopelvic parameters of spondylolysis patients, and their relationship with spondylolisthesis, disc degeneration, and age in a Taiwanese population.

Methods

Radiographic sagittal spinopelvic parameters for 45 spondylolysis patients and 32 healthy people were evaluated, including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), and lumbar lordosis (LL). The spinopelvic parameters were compared between spondylolytic and control groups. These parameters were further compared between spondylolytic subjects with and without spondylolisthesis, with and without high-grade disc degeneration, and young (< 30 years old) and middle-aged.

Results

The PI and LL of the spondylolytic group (52.6°±12.0° and 41.3°±15.2°) were significantly higher than those of the healthy control group (47.16°±7.95° and 28.22°±10.65°). Further analysis of the spondylolytic patients revealed that those with high-grade disc degeneration were more prone to spondylolisthesis (92.3 %) compared to those without (50 %; p = 0.001). The middle-aged group had significantly higher rates of spondylolisthesis (80 %) and high-grade disc degeneration (52.4 %) compared with those for the young group (45 and 16.7 %, respectively; p = 0.017 and 0.047, respectively). No statistically significant difference in the sagittal spinopelvic parameters was found when spondylolytic patients were divided according to the occurrence of spondylolisthesis or high-grade disc degeneration.

Conclusions

In a Taiwanese population, PI and LL were significantly larger in spondylolytic patients. Disc degeneration and age were associated with the occurrence of spondylolisthesis. Ethnological differences should thus be taken into account when making clinical decisions regarding spondylolysis in a Taiwanese population.

Increased sagittal diameter of the vertebral arch aids in diagnosis of lumbar spondylolysis

OBJECTIVE

To identify a diagnostic indicator of lumbar spondylolysis visible in plain X-ray films.

METHODS

One hundred and seventy-two patients with low back pain who received X-ray and computerized tomography (CT) examinations were identified and studied. They were divided into three groups: the spondylosis without spondylolisthesis (SWS) group, comprising 67 patients with bilateral pars interarticularis defects at L5 and without spondylolisthesis, the isthmic spondylolisthesis (IS) group, comprising 74 patients with L5/S1 spondylolisthesis and bilateral L5 pars interarticularis defects, and the control group, comprising 31 patients with low back pain but without spondylolysis. The sagittal diameters of the vertebral arch (SDVAs) of L4 and L5 were measured in lateral X-ray image, and the differences in SDVA between L4 and L5 (DSL4-5) in each case were calculated and analyzed.

RESULTS

There were no significant differences in demographic characteristics among the three groups. In the SWS and IS groups, the SDVA of L5 was significantly longer than the SDVA of L4 (p < 0.001), whereas no significant difference found in the control group (p > 0.05). DSL4-5, in which the SDVA of L4 was subtracted from the SDVA of L5, significantly differed among the three groups (p < 0.001), and the normal threshold was provisionally determined to be 1.55 mm.

CONCLUSIONS

In bilateral L5 spondylolysis, the SDVA of L5 is wider than the SDVA of L4, and this difference is greater in isthmic spondylolisthesis. This sign in lateral X-rays may provide a simple and convenient aid for the diagnosis of spondylolysis.

Age-Specific Characteristics of Lumbopelvic Alignment in Patients with Spondylolysis: How Bilateral L5 Spondylolysis Influences Lumbopelvic Alignment During the Aging Process

BACKGROUND

To elucidate the influence of spondylolysis on age-related lumbar degenerative changes, age-specific lumbopelvic alignment in patients with or without spondylolysis was examined.

METHODS

Sagittal reconstructed computed tomography images of the lumbar spine in consecutive patients (n = 581) undergoing computed tomography scans of abdominal or lumbar regions for reasons other than low back disorders were obtained. Lumbar lordosis (LL), L5-S1 angle, and sacral slope (SS) were measured. Lumbopelvic parameters in patients with or without spondylolysis were evaluated in 3 age groups (<50, 50-69, and ≥70). The influence of bilateral L5 spondylolysis (L5-lysis) and L5 vertebral slip on each lumbopelvic parameter, as well as correlation between cross-sectional area (CSA) of paraspinal muscles and the degree of vertebral slip, were examined by multiple regression analysis.

RESULTS

Patients with bilateral spondylolysis showed greater LL and SS than patients without spondylolysis. When analyzing the influence of L5-lysis, only elderly patients (≥70) with L5-lysis showed significantly greater LL and SS than nonspondylolysis (nonlysis) patients. L5-lysis patients more frequently showed L5 vertebral slip than nonlysis patients, and a smaller L5-S1 angle was observed when L5 vertebral slip accompanied L5-lysis. The degree of vertebral slip was significantly correlated with CSA of psoas muscles, but not with CSA of paraspinal extensor muscles.

CONCLUSIONS

When patients have L5-lysis, lumbar lordosis and pelvic anteversion occurred age dependently. In elderly patients with L5-lysis, L5 vertebral slip with decrease of the L5-S1 angle occurs frequently. The progression of vertebral slip was correlated with atrophy of psoas muscles, but not that of paraspinal extensor muscles.

Difference of Sagittal Alignment between Adolescents with Symptomatic Lumbar Isthmic Spondylolisthesis and the General Population

This case-control study aimed to investigate differences in the sagittal spinal parameters between the symptomatic spondylolisthesis patients and the general population. Twenty-nine adolescent patients with symptomatic lumbar isthmic spondylolisthesis were included. For each patient, two age-matched, gender-matched and BMI-matched controls were enrolled. Comparison analyses detected higher values in the case group for the following parameters: CL (−22.06 ± 7.552° versus −20.36 ± 7.016°, P < 0.001), T1 Slope (19.84 ± 8.708° versus 13.99 ± 6.537°, P = 0.001), PT (21.54 ± 9.082° versus 8.87 ± 7.863°, P < 0.001), PI (64.45 ± 13.957° versus 43.60 ± 9.669°, P < 0.001), SS (42.90 ± 9.183° versus 34.73 ± 8.265°, P < 0.001), LL (−50.82 ± 21.596° versus −43.78 ± 10.356°, P = 0.042), SVA (16.99 ± 14.625 mm versus 0.32 ± 31.824 mm, P = 0.009), L5 Slope (33.95 ± 13.567° versus 19.03 ± 6.809°, P < 0.001), and L5I (8.90 ± 6.556° versus 1.29 ± 6.726°, P < 0.001). Conversely, TS-CL (6.56 ± 6.716° versus 11.04 ± 7.085°, P = 0.006), cSVA (11.31 ± 6.867 mm versus 17.92 ± 11.832 mm, P = 0.007), and TLK (−2.66 ± 10.101° versus 2.71 ± 7.708°, P = 0.007) were smaller in the case group. Slippage percentage was most correlated with PI (r = 0.530, P = 0.003), followed by PT (r = 0.465, P = 0.011) and L5I (r = 0.433, P = 0.019). Results of binary logistic regression showed that the main risk factor of isthmic spondylolisthesis was PI (OR = 1.145, 95%CI = 1.083–1.210, P < 0.001). Further subgroup analysis also showed that PI was the main risk factor of isthmic spondylolisthesis in the female adolescents (OR = 1.237, 95%CI = 1.086–1.493, P = 0.003) and in the male adolescents (OR = 1.523, 95%CI = 1.093–2.123, P = 0.013). PI was the main risk factor for adolescent symptomatic isthmic spondylolisthesis in the Chinese Han adolescents. The greater PI indicated the higher the progressive risk of spondylolisthesis. In these isthmic spondylolisthesis adolescents, the body always inclined forward and lumbar and cervical lordosis increased.

Factors Associated with the Symptoms of Young Adults with L5 Spondylolysis

Study Design

A retrospective cohort study.

Purpose

To investigate the factors affecting symptoms in young adults with L5 spondylolysis.

Overview of Literature

L5 spondylolysis is a common disease. However, not all patients diagnosed with L5 spondylolysis exhibit symptoms. This study examined the factors associated with the symptoms of young adults with L5 spondylolysis.

Methods

The medical records of 70 young adults (mean age, 31.1 years; range, 20–39 years) with L5 spondylolysis treated at the authors’ spine center between March 2008 and February 2015 were reviewed systematically. The symptomatic group (n=46) presented with symptoms, such as back pain and/or intermittent lower limb radiating pain, whereas the asymptomatic group (n=24) did not. Age, sex, body mass index (BMI), adjacent disc degeneration, facet degeneration, and measured spino-pelvic parameters (pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, sacral inclination, and sacral table angle) were investigated with respect to the presence of symptoms. Adjacent disc degeneration was evaluated using T2-weighted sagittal magnetic resonance imaging (MRI, Pfirrmann classification), whereas facet degeneration was evaluated using T2-weighted axial MRI (Grogan classification).

Results

Significant differences in the BMI (p =0.032), L4–5 disc degeneration (p =0.030), L5–S1 disc degeneration (p =0.046), L4–5 facet degeneration (p =0.041), and L5–S1 facet degeneration (p =0.027) were observed between the symptomatic and asymptomatic groups. However, multivariate logistic regression analysis revealed that L5–S1 disc degeneration (p =0.033) was the only significant factor.

Conclusions

BMI and adjacent disc and facet degeneration may be associated with the manifestation of disease symptoms in young adults with L5 spondylolysis, and the likelihood of the patient exhibiting symptoms increases with increasing severity of L5–S1 disc degeneration.

Acquired spondylolysis and spinopelvic sagittal alignment

Acquired spondylolysis represents an uncommon complication of spine surgery, of an unknown incidence and etiology. We studied patients presenting this rare entity, with the purpose to investigate the incidence, imaging findings, patients' clinical characteristics, as well as to provide an interpretation of the mechanisms that may lead to this phenomenon. The presented working hypothesis, regarding etiology, suggests that there is a relation between variations in spinopelvic sagittal alignment and acquired spondylolysis. Between January 2010 and January 2015, six patients presented spondylolysis after short-segment transforaminal lumbar interbody fusion, at a mean time of 43 months after surgery. The preoperative intactness and postoperative defect of pars interarticularis were documented with computed tomography scans in all patients. Standard radiographical spinopelvic parameters were measured before and after surgery. The optimum values of lumbar lordosis (LL) and pelvic incidence minus lumbar lordosis modifier (PI-LL mismatch) were calculated as well. The incidence of acquired spondylolysis was 0.95% among patients with short-segment lumbar fusion. Patients presented high-grade PI with a vertically orientated sacral endplate, while LL was found 9° greater and PI-LL mismatch 9° lower than the respective optimum values, indicating a non-harmonized alignment. In conclusion, acquired spondylolysis, though rare, may occur in patients with high-grade PI and sacral slope, and suboptimal spinopelvic sagittal alignment after lumbar spine surgery, thereby highlighting the importance of detailed preoperative planning in spine surgery, along with the study of sagittal balance.

Differences in Fundamental Sagittal Pelvic Parameters Based on Age, Sex, and Race

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To determine whether age, sex, and race have independent effects on sagittal pelvic parameters.

SUMMARY OF BACKGROUND DATA

Pelvic parameters and sagittal balance correlate with health-related quality of life and are important for patient assessment and surgical planning. Age, sex, and race are 3 unalterable patient factors that may influence pelvic morphology.

METHODS

We conducted a retrospective review of consecutive adult patients who presented to our radiology practice between 2010 and 2015 and had a standing, lateral lumbosacral radiograph. Any patients without both femoral heads and L1-S1 visible on the radiograph, and any patients presenting with traumatic injury, coronal deformity, prior instrumentation, spondylolisthesis, or neoplasm of the spine were excluded. Univariate analysis determined differences in measurements among African American, white, and Hispanic races, as well as between male and female sexes. Correlation analysis between age and different measurements was also conducted. Multivariable regression was then used to determine the independent effect of age, sex, and race on pelvic parameters.

RESULTS

We investigated 1801 adults (older than 18 y) and 1246 had a recorded race. There were 1165 women, 636 men, 525 whites, 404 African Americans, and 317 Hispanics. Multivariable regression demonstrated a statistically significant increase in pelvic tilt (PT), pelvic incidence (PI), and pelvic incidence-lumbar lordosis (PI-LL) with aging, and statistically significant decrease in sacral slope (SS) and LL with aging. Women had a statistically greater LL than men. African Americans had a statistically smaller PT and greater SS and PI-LL relative to whites, while Hispanics had a statistically smaller PT and PI-LL, and a statistically greater SS and LL relative to whites.

CONCLUSIONS

Pelvic parameters were different between sexes, among races, and changed with age. These findings are important for patient assessment and preoperative planning to obtain optimal sagittal balance.

LEVEL OF EVIDENCE

Level 3.