Measurements of lumbopelvic lordosis using the pelvic radius technique as it correlates with sagittal spinal balance and sacral translation

Global Sagittal Alignment and Clinical Outcomes after 1-3 Short-Segment Lumbar Fusion in Degenerative Spinal Diseases

Study Design

Level III retrospective study.

Purpose

We investigated the impact of short-segment lumbar fusion on the restoration of global sagittal alignment and the correlations between spino-pelvic parameters and clinical outcomes.

Overview of Literature

Sagittal imbalance leads to energy consumption and pain in maintaining a standing position. For adult spinal deformity, it is critical to create optimal lumbar lordosis (LL) in order to achieve restoration of sagittal imbalance. However, surgeons do not pay attention to correcting LL in short-segment lumbar fusion.

Methods

A total of 69 patients with transforaminal lumbar interbody fusion (TLIF) for degenerative spinal disease were evaluated with a minimum 2-year follow-up. All patients underwent TLIF with hyper-lordotic angle cages to achieve higher LL. Radiological spino-pelvic parameters including sagittal vertical axis (SVA) and clinical outcomes using the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) were evaluated.

Results

The average LL was 35.8°±9.9° before surgery, 42.3°±9.3° 1 year after surgery, and 40.3°±10.2° 2 years after surgery (p <0.01). The average SVA was 43.1±6.2 mm before surgery, 21.2±4.9 mm 1 year after surgery, and 34.0±4.7 mm 2 years after surgery (p <0.01). The average LL and SVA improved in two- or three-segment fusion, but not in one-segment fusion. The correlation between ΔLL and ΔSVA was significant in all segment fusions. The correlation between ΔLL and ΔSVA was more significant at the L4-5 and L5-S1 segments than at L3-4. ODI was significantly correlated with SVA (p <0.05). NRS showed no correlation with the radiological parameters.

Conclusions

Two- or three-segment lumbar fusion using hyper-lordotic angle cages improved LL and SVA. A significant correlation between the correction of LL and SVA was found. Higher correction of LL using hyper-lordotic angle cages is thus recommended in short-segment lumbar fusion, since postoperative improvements of SVA significantly affect clinical outcomes.

Assessment of Lumbar Lordosis Distribution with a Novel Mathematical Approach and Its Adaptation for Lumbar Intervertebral Disc Degeneration

Introduction

Low back pain and disc degeneration could be linked to global spinal geometry. Our study aimed to develop a reliable new mathematical method to assess the local distribution of total lumbar lordosis with a single numeric parameter and compare it with lumbar intervertebral disc degeneration using routine MRI scans.

Methods

An online, open access, easy-to-use platform for measurements was developed based on a novel mathematical approach using MRIs of 60 patients. Our Spinalyze Software can be used online with uploaded MRIs. Several new parameters were introduced and assessed to describe variation in segmental lordosis distribution with a single numerical value. The Pfirrmann grading system was used for the classification of lumbar intervertebral disc degeneration. Relationships were investigated between the grade categories of L1-S1 lumbar discs and the MRI morphological parameters with correlation analysis.

Results

Results confirm that the determination of measurement points and calculated parameters are reliable (ICCs and Pearson r values > 0.90), and these parameters were independent of gender. The digression percentage (K%), one of our new parameters, did not show a statistical relationship with the Cobb-angle. According to our results, the maximum deflection breaking-point of lumbar lordosis and its location can be different with the same Cobb-angle and the distribution of global lordosis is uneven because the shape of the lumbar lordosis is shifted downward and centered around the L4 lumbar vertebra. The interobserver reliability of the Pfirrmann grades reading was in the excellent agreement category (88.33% agreement percentage, 0.84 kappa), and digression percentage (K%) showed a significant negative correlation with all L1-S1 disc grades with increasing r correlation values. This means that the smaller the value of digression percentage (K%), the more the number of worn discs in the lower lumbar sections.

Conclusions

Spinalyze Software based on a novel mathematical approach provides a free, easy-to-use, reliable, and online measurement tool using standard MRIs to approximate the curvature of lumbar lordosis. The new reliable K% (digression percentage) is one single quantitative parameter to assess the local distribution of total lumbar lordosis. The results indicate that digression percentage (K%) may possibly be associated with the development of lumbar intervertebral disc degeneration. Further evaluation is needed to assess its behavior and advantage.

Classification System of the Sagittal Integral Morphotype in Children from the ISQUIOS Programme (Spain)

The sagittal spinal morphology presents 4 physiological curvatures that increase endurance to axial compression forces and allow adequate postural balance. These curves must remain within normal ranges to achieve a static and dynamic balance, a correct functioning of the muscles and an adequate distribution of the loads, and thus minimize the injury risk. The purpose of this study was to categorize the sagittal spinal alignment according to the different morphotypes obtained for each curve in standing, slump sitting, and trunk forward bending positions in schoolchildren. It was a cross-sectional study. Sagittal spinal curvatures were assessed in 731 students from 16 elementary schools. In the sagittal standing position assessment, 70.45% and 89.06% of schoolchildren presented a “normal” morphotype for both dorsal and lumbar curves, respectively. After the application of the “Sagittal Integral Morphotype” protocol according to the morphotypes obtained in the three positions assessment (standing, slump sitting, and trunk forward bending), it was observed how the frequency of normal morphotypes for the dorsal and lumbar curve decreased considerably (only 32% and 6.6% of children obtained a “normal sagittal integral morphotype” for the thoracic and lumbar curvatures, respectively). These results show how it is necessary to include the slump sitting and trunk forward bending assessment as part of the protocol to define the “integral” sagittal alignment of the spine and establish a correct diagnosis. The use of the diagnostic classification presented in this study will allow early detection of misalignment not identified with the assessment of standing position.

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.

The pelvic radius technique in the assessment of spinopelvic sagittal alignment of degenerative spondylolisthesis and lumbar spinal stenosis

BACKGROUND

Degenerative spondylolisthesis (DS) and lumbar spinal stenosis (LSS) are the most common degenerative spinal diseases. The evaluating of spinopelvic sagittal alignment of the two diseases using pelvic radius (PR) technique have not been reported. The purpose of this study was to use PR measurement technique to compare the differences in spinopelvic sagittal alignment between DS and LSS.

METHODS

A total of 145 patients with DS or LSS were retrospectively reviewed. Seventy patients with DS (DS group) and 75 age-matched patients with LSS (LSS group) were enrolled. Spinopelvic parameters including pelvic angle (PA), regional lumbopelvic lordosis (PR-L1, PR-L2, PR-L3, PR-L4 and PR-L5), total lumbopelvic lordosis (PR-T12), pelvic morphology (PR-S1), sagittal vertical axis from the C7 plumb line (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), L4 slope and L5 slope were assessed in the two groups. Several parameters of DS and LSS group were compared with the normal population (NP).

RESULTS

The PR-L4, PR-L5 and PR-S1 in the DS group were significantly smaller than those in the LSS group. There was no difference in PR-T12 between the DS group and NP (p > 0.05), while PR-T12 of the LSS group were significantly lower (p < 0.01). Degree of correlations among spinopelvic parameters differed between the two groups. PR-T12 of the DS group was more strongly correlated with PA (r = -0.829, p < 0.001) than with LL (r = 0.664, p < 0.001), TK (r = 0.582, p < 0.001). PR-T12 of the LSS group was more strongly correlated with LL (r = 0.854, p < 0.001), TK (r = 0.616, p < 0.001) than with PA (r = -0.582, p < 0.001).

CONCLUSIONS

PR-L4 and PR-L5 may be the predisposing factors for DS development. Spinopelvic morphology differed in patients with DS and LSS compared to NP. The compensatory mechanisms to maintain spinopelvic sagittal alignment in DS and LSS patients may be different.

Accuracy of a Radiological Evaluation Method for Thoracic and Lumbar Spinal Curvatures Using Spinous Processes

OBJECTIVE

The purpose of this study was to assess a radiographic method for spinal curvature evaluation in children, based on spinous processes, and identify its normality limits.

METHODS

The sample consisted of 90 radiographic examinations of the spines of children in the sagittal plane. Thoracic and lumbar curvatures were evaluated using angular (apex angle [AA]) and linear (sagittal arrow [SA]) measurements based on the spinous processes. The same curvatures were also evaluated using the Cobb angle (CA) method, which is considered the gold standard. For concurrent validity (AA vs CA), Pearson's product-moment correlation coefficient, root-mean-square error, Pitman- Morgan test, and Bland-Altman analysis were used. For reproducibility (AA, SA, and CA), the intraclass correlation coefficient, standard error of measurement, and minimal detectable change measurements were used.

RESULTS

A significant correlation was found between CA and AA measurements, as was a low root-mean-square error. The mean difference between the measurements was 0° for thoracic and lumbar curvatures, and the mean standard deviations of the differences were ±5.9° and 6.9°, respectively. The intraclass correlation coefficients of AA and SA were similar to or higher than the gold standard (CA). The standard error of measurement and minimal detectable change of the AA were always lower than the CA.

CONCLUSION

This study determined the concurrent validity, as well as intra- and interrater reproducibility, of the radiographic measurements of kyphosis and lordosis in children.

Spinopelvic Parameters in Asymptomatic Subjects Without Spine Disease and Deformity: A Systematic Review With Meta-Analysis

STUDY DESIGN

A systematic review with meta-analysis.

OBJECTIVE

To combine published data, focusing on the development of optimal spinopelvic parameters in adult asymptomatic subjects without spine deformity while taking into consideration the impact of potential confounders.

SUMMARY OF BACKGROUND DATA

A well-grounded approach to define the optimal spinopelvic parameters is necessary for planning surgical correction of spine deformity.

MATERIALS

Selection criteria: (1) randomized and nonrandomized prospective, cross-sectional, and retrospective studies; (2) participants: asymptomatic subjects without spine deformity aged above 18 years; (3) studied parameters: lumbar lordosis (LL), pelvic incidence, sacral slope, and pelvic tilt; (4) potential confounders: method of measurement, sex, age, ethnicity, weight, height, and body mass index. Search method: Ovid MEDLINE (1946-current) and EMBASE (1980-current), all years through October 2015 were included. Data were collected: number of enrolled subjects, means of the studied characteristics, SD, SE of the means, 95% confidence intervals. A meta-analysis was performed to evaluate the pooled means and range of optimal values (pooled mean±pooled SD) taking into consideration the impact of confounders. The GRADE approach was applied to evaluate the level of evidence.

RESULTS

Seventeen of 1018 studies were included (2926 subjects from 9 countries). The pooled means and the optimal ranges were: LL (L1-S1), 54.6 (42-67) degrees; LL (L1-L5), 37.0 (22-53) degrees; pelvic incidence, 50.6 (39-62) degrees; sacral slope, 37.7 (28-48) degrees; pelvic tilt, 12.6 (3-22) degrees. The pooled results were statistically significant (P<0.001), but heterogeneous. Impact of the following confounders was revealed: method of measurement, ethnicity, age, and body mass index. A methodology was created to define an individualized optimal value and range of each studied parameter taking into consideration the influence of confounders.

CONCLUSIONS

The pooled results and developed methodology can be used as diagnostic criteria for evaluation of the spinopelvic parameters, planning of surgical interventions and evaluation of the treatment effect.

Hyperlordosis is Associated With Facet Joint Pathology at the Lower Lumbar Spine

STUDY DESIGN

A retrospective study.

OBJECTIVE

Our study opted to clarify the remaining issues of lumbar lordosis (LL) with regard to (1) its physiological values, (2) age, (3) sex, and (4) facet joint (FJ) arthritis and orientation using computed tomography (CT) scans.

SUMMARY OF BACKGROUND DATA

Recent studies have questioned whether LL really decreases with age, but study sample sizes have been rather small and mostly been based on x-rays. As hyperlordosis increases the load transferred through the FJs, it seems plausible that hyperlordosis may lead to FJ arthritis at the lower lumbar spine.

METHODS

We retrospectively analyzed the CT scans of 620 individuals, with a mean age of 42.5 (range, 14-94) years, who presented to our traumatology department and underwent a whole-body CT scan, between 2008 and 2010. LL was evaluated between the superior endplates of L1 and S1. FJs of the lumbar spine were evaluated for arthritis and orientation between L2 and S1.

RESULTS

(1) The mean LL was 49.0 degrees (SD 11.1 degrees; range, 11.4-80.1 degrees). (2) LL increased with age and there was a significant difference in LL in our age groups (30 y and below, 31-50, 51-70, and ≥71 y and above) (P=0.02). (3) There was no significant difference in LL between females and males (50 and 49 degrees) (P=0.17). (4) LL showed a significant linear association with FJ arthritis [P=0.0026, OR=1.022 (1.008-1.036)] and sagittal FJ orientation at L5/S1 (P=0.001). In a logistic regression analysis, the cutoff point for LL was 49.4 degrees.

CONCLUSIONS

This is the largest CT-based study on LL and FJs. LL significantly increases with age. As a novelty finding, hyperlordosis is significantly associated with FJ arthritis and sagittal FJ orientation at the lower lumbar spine. Thus, hyperlordosis may present with back pain and patients may benefit from surgical correction, for example, in the setting of trauma.

Does Degenerative Lumbar Spine Disease Influence Femoroacetabular Flexion in Patients Undergoing Total Hip Arthroplasty?

BACKGROUND

Sitting pelvic tilt dictates the proximity of the rim of the acetabulum to the proximal femur and, therefore, the risk of impingement in patients undergoing total hip arthroplasty (THA). Sitting position is achieved through a combination of lumbar spine segmental motions and/or femoroacetabular articular motion in the lumbar-pelvic-femoral complex. Multilevel degenerative disc disease (DDD) may limit spine flexion and therefore increase femoroacetabular flexion in patients having THAs, but this has not been well characterized. Therefore, we measured standing and sitting lumbar-pelvic-femoral alignment in patients with radiographic signs of DDD and in patients with no radiographic signs of spine arthrosis.

QUESTIONS/PURPOSES

We asked: (1) Is there a difference in standing and sitting lumbar-pelvic-femoral alignment before surgery among patients undergoing THA who have no radiographic signs of spine arthrosis compared with those with preexisting lumbar DDD? (2) Do patients with lumbar DDD experience less spine flexion moving from a standing to a sitting position and therefore compensate with more femoroacetabular flexion compared with patients who have no radiographic signs of arthrosis?

METHODS

Three hundred twenty-five patients undergoing primary THA had preoperative low-dose EOS spine-to-ankle lateral radiographs in standing and sitting positions. Eighty-three patients were excluded from this study for scoliosis (39 patients), spondylolysis (15 patients), not having five lumbar vertebrae (7 patients), surgical or disease fusion (11 patients), or poor image quality attributable to high BMI (11 patients). In the remaining 242 of 325 patients (75%), two observers categorized the lumbar spine as either without radiographic arthrosis or having DDD based on defined radiographic criteria. Sacral slope, lumbar lordosis, and proximal femur angles were measured, and these angles were used to calculate lumbar spine flexion and femoroacetabular flexion in standing and sitting positions. Patients were aligned in a standardized sitting position so that their femurs were parallel to the floor to achieve approximately 90° of apparent hip flexion.

RESULTS

After controlling for age, sex, and BMI, we found patients with DDD spines had a mean of 5° more posterior pelvic tilt (95% CI, -2° to -8° lower sacral slope angles; p < 0.01) and 7° less lumbar lordosis (95% CI, -10° to -3°; p < 0.01) in the standing position compared with patients without radiographic arthrosis. However, in the sitting position, patients with DDD spines had 4° less posterior pelvic tilt (95% CI, 1°-7° higher sacral slope angles; p = 0.02). From standing to sitting position, patients with DDD spines experienced 10° less spine flexion (95% CI, -14° to -7°; p < 0.01) and 10° more femoroacetabular flexion (95% CI, 6° to 14°; p < 0.01).

CONCLUSIONS

Most patients undergoing THA sit in a similar range of pelvic tilt, with a small mean difference in pelvic tilt between patients with DDD spines and those without radiographic arthrosis. However, in general, the mechanism by which patients with DDD of the lumbar spine achieve sitting differs from those without spine arthrosis with less spine flexion and more femoroacetabular flexion.

CLINICAL RELEVANCE

When planning THA, it may be important to consider which patients sit with less posterior pelvic tilt and those who rotate their pelvises forward to achieve a sitting position, as both mechanisms will limit or reduce the functional anteversion of the acetabular component in a patient with a THA. Our study provides some additional perspective on normal relationships between pelvic tilt and femoroacetabular flexion, but further research might better characterize this relationship in outliers and the possible implications for posterior instability after THA.

Anterior Cervical Discectomy and Fusion Alters Whole-Spine Sagittal Alignment

PURPOSE

Anterior cervical discectomy and fusion (ACDF) has become a common spine procedure, however, there have been no previous studies on whole spine alignment changes after cervical fusion. Our purpose in this study was to determine whole spine sagittal alignment and pelvic alignment changes after ACDF.

MATERIALS AND METHODS

Forty-eight patients who had undergone ACDF from January 2011 to December 2012 were enrolled in this study. Cervical lordosis, thoracic kyphosis, lumbar lordosis, sagittal vertical axis (SVA), and pelvic parameters were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. Clinical outcomes were assessed using Visual Analog Scale (VAS) scores and Neck Disability Index (NDI) values.

RESULTS

Forty-eight patients were grouped according to operative method (cage only, cage & plate), operative level (upper level: C3/4 & C4/5; lower level: C5/6 & C6/7), and cervical lordosis (high lordosis, low lordosis). All patients experienced significant improvements in VAS scores and NDI values after surgery. Among the radiologic parameters, pelvic tilt increased and sacral slope decreased at 12 months postoperatively. Only the high cervical lordosis group showed significantly-decreased cervical lordosis and a shortened SVA postoperatively. Correlation tests revealed that cervical lordosis was significantly correlated with SVA and that SVA was significantly correlated with pelvic tilt and sacral slope.

CONCLUSION

ACDF affects whole spine sagittal alignment, especially in patients with high cervical lordosis. In these patients, alteration of cervical lordosis to a normal angle shortened the SVA and resulted in reciprocal changes in pelvic tilt and sacral slope.

Reliability of three landmarking methods for dual inclinometry measurements of lumbar flexion and extension

Background

To examine the intra and inter-rater reliability of lumbar flexion and extension measurements attained using three landmarking methods for dual inclinometry.

Methods

This was a repeated measures reliability study. Convenience sampling was used to obtain forty volunteer subjects. Two assessors measured a series of lumbar flexion and extension movements using the J-Tech™ dual inclinometer. Three different landmarking methods were used: 1) straight palpation of PSIS and L1, 2) palpation of PSIS and the site of the nearest 5 cm interval point closest to L1 and 3) location of PSIS and 15 cm cephalad. Upon landmarking, adhesive tape was used to mark landmarks and the inclinometer was placed on sites for three trials of flexion and extension. Tape was removed and landmarks were relocated by the same assessor (intra-rater) for an additional three trials; and this process was repeated by a second assessor (inter-rater). Reliability was determined using intra-class correlation coefficients.

Results

Reliability within a set of three repetitions was very high (ICCs > 0.90); intra-rater reliability after relocating landmarks was high (ICCs > 0.80); reliability between therapists was moderate to high (0.60 > ICCs < 0.76). Assessment of flexion and extension movements by straight palpation of bony landmarks as in the Straight palpation of PSIS and L1 method (ICC: Flexion 0.60; Extension 0.74) was found to be marginally less reliable than the other two landmarking measurement strategies (ICC: Flexion 0.66; Extension 0.76).

Conclusion

All three methods of land marking are reliable. We recommend the use of the PSIS to 15 cm cephalad method as used in the modified-modified Schobers test as it is the simplest to perform and aligns with current clinical practice.

Lumbar lordosis and sacral slope in lumbar spinal stenosis: standard values and measurement accuracy

STUDY DESIGN

Radiological study.

PURPOSE

To asses standard values, intra- and interobserver reliability and reproducibility of sacral slope (SS) and lumbar lordosis (LL) and the correlation of these parameters in patients with lumbar spinal stenosis (LSS).

METHODS

Anteroposterior and lateral X-rays of the lumbar spine of 102 patients with LSS were included in this retrospective, radiologic study. Measurements of SS and LL were carried out by five examiners. Intraobserver correlation and correlation between LL and SS were calculated with Pearson's r linear correlation coefficient and intraclass correlation coefficients (ICC) were calculated for inter- and intraobserver reliability. In addition, patients were examined in subgroups with respect to previous surgery and the current therapy.

RESULTS

Lumbar lordosis averaged 45.6° (range 2.5°-74.9°; SD 14.2°), intraobserver correlation was between Pearson r = 0.93 and 0.98. The measurement of SS averaged 35.3° (range 13.8°-66.9°; SD 9.6°), intraobserver correlation was between Pearson r = 0.89 and 0.96. Intraobserver reliability ranged from 0.966 to 0.992 ICC in LL measurements and 0.944-0.983 ICC in SS measurements. There was an interobserver reliability ICC of 0.944 in LL and 0.990 in SS. Correlation between LL and SS averaged r = 0.79. No statistically significant differences were observed between the analyzed subgroups.

CONCLUSION

Manual measurement of LL and SS in patients with LSS on lateral radiographs is easily performed with excellent intra- and interobserver reliability. Correlation between LL and SS is very high. Differences between patients with and without previous decompression were not statistically significant.

The effect of spinal curvature on the photogrammetric assessment on static balance in elderly women

BACKGROUND

Involutional changes to the body in elderly patients affect the shape of the spine and the activity of postural muscles. The purpose of this study was to assess the influence of age-related changes in spinal curvature on postural balance in elderly women.

METHODS

The study population consisted of 90 women, with a mean age of 70 ± 8.01 years. Static balance assessments were conducted on a tensometric platform, and posturographic assessments of body posture were performed using a photogrammetric method based on the Projection Moiré method.

RESULTS

The results obtained were analysed using the Spearman's rank correlation coefficient test. We found a statistically significant correlation between body posture and the quality of the balance system response based on the corrective function of the visual system. The shape of the spinal curvature influenced postural stability, as measured by static posturography. Improvement in the quality of the balance system response depended on corrective information from the visual system and proprioceptive information from the paraspinal muscles.

CONCLUSIONS

The sensitivity of the balance system to the change of centre of pressure location was influenced by the direction of the change in rotation of the shoulder girdle and spine. Development of spinal curvature in the sagittal plane and maintenance of symmetry in the coronal and transverse planes are essential for correct balance control, which in turn is essential for the development of a properly proportioned locomotor system.

A review of methods for evaluating the quantitative parameters of sagittal pelvic alignment

BACKGROUND CONTEXT

The sagittal alignment of the pelvis represents the basic mechanism for maintaining postural equilibrium, and a number of methods were developed to assess normal and pathologic pelvic alignments from two-dimensional sagittal radiographs in terms of positional and anatomic parameters.

PURPOSE

To provide a complete overview of the existing methods for quantitative evaluation of sagittal pelvic alignment and summarize the relevant publications.

STUDY DESIGN

Review article.

METHODS

An Internet search for terms related to sagittal pelvic alignment was performed to obtain relevant publications, which were further supplemented by selected publications found in their lists of references. By summarizing the obtained publications, the positional and anatomic parameters of sagittal pelvic alignment were described, and their values and relationships to other parameters and features were reported.

RESULTS

Positional pelvic parameters relate to the position and orientation of the observed subject and are represented by the sacral slope, pelvic tilt, pelvic overhang, sacral inclination, sacrofemoral angle, sacrofemoral distance, pelvic femoral angle, pelvic angle, and sacropelvic translation. Anatomic pelvic parameters relate to the anatomy of the observed subject and are represented by the pelvisacral angle (PSA), pelvic incidence (PI), pelvic thickness (PTH), sacropelvic angle (PRS1), pelvic radius (PR), femorosacral posterior angle (FSPA), sacral table angle (STA), and sacral anatomic orientation (SAO). The review was mainly focused on the evaluation of anatomic pelvic parameters, as they can be compared among subjects and therefore among different studies. However, ambiguous results were yielded for normal and pathologic subjects, as the reported values show a relatively high variability in terms of standard deviation for every anatomic parameter, which amounts to around 10 mm for PTH and PR; 10° for PSA, PI, and SAO; 9° for PRS1 and FSPA; and 5° for STA in the case of normal subjects and is usually even higher in the case of pathologic subjects. Among anatomic pelvic parameters, PI was the most studied and therefore represents a key parameter in the complex framework of sagittal spinal alignment and related deformities. From the reviewed studies, the regression lines for PI and the corresponding age of the subjects indicate that PI tends to increase with age for normal (PI = +0.17 × age+46.40) and scoliotic (PI = +0.20 × age+50.52) subjects and decrease with age for subjects with spondylolisis or spondylolisthesis (PI = -0.26 × age+75.69).

CONCLUSIONS

Normative values for anatomic parameters of sagittal pelvic alignment do not exist because the variability of the measured values is relatively high even for normal subjects but can be predictive for spinal alignment and specific spinopelvic pathologies.

The influence of backrest inclination on buttock pressure

Objective

To assess the effects of backrest inclination of a wheelchair on buttock pressures in spinal cord injured (SCI) patients and normal subjects.

Method

The participants were 22 healthy subjects and 22 SCI patients. Buttock pressures of the participants were measured by a Tekscan® pressure sensing mat and software while they were sitting in a reclining wheelchair. Buttock pressures were recorded for 90°, 100°, 110°, 120° and 130° seat-to-back angles at the ischial tuberosity (IT) and sacrococcygeal (SC) areas. Recordings were made at each angle over four seconds at a sampling rate of 10 Hz.

Results

The side-to-side buttock pressure differences in the IT area for the SCI patients was significantly greater than for the normal subjects. There was no significant difference between the SCI patients and the normal subjects in the buttock pressure change pattern of the IT area. Significant increases in pressure on the SC area were found as backrest inclination angle was changed to 90°, 100° and 110° in the normal subjects, but no significant differences were found in the SCI patients.

Conclusion

Most of the SCI patients have freeform posture in wheelchairs, and this leads to an uneven distribution of buttock pressure. In the SCI patients, the peak pressure in the IT area reduced as the backrest angle was increased, but peak pressure at the SC area remained relatively unchanged. To reduce buttock pressure and prevent pressure ulcers and enhance ulcer healing, it can be helpful for tetraplegic patients, to have wheelchair seat-to-back angles above 120°.

Lumbo-pelvic lordosis and the pelvic radius technique in the assessment of spinal sagittal balance: strengths and caveats

INTRODUCTION

The two main methodologies described for the assessment of spinal sagittal alignment are the pelvic radius (PR) technique and that based on measures of the Pelvic Incidence (PI) and Spino-Sacral Angle (SSA). Both methods stress the fundamental relationship between the anatomical position and orientation of the sacrum within the pelvis and the spinal curves above. The aim of the current study was to assess the strengths and potential weaknesses of the PR technique. The PR technique uses measures based on a line (the PR), drawn between the hip axis and the posterior corner of the S1 endplate. The angle formed between the PR line and the sacral endplate, PRS1, is a developmental measure of sacropelvic morphology. Geometrically, PI and PRS1 are approximately complementary angles and both reflect reciprocal alterations in pelvic tilt (for PI) or angulation (for PRS1) and the slope of the S1 endplate. The angle formed between PR and T12, the PR-T12, reflects a combined measure of pelvic morphology and lumbar lordosis. It appears to be a useful measure, which provides a simple and rapid assessment of lumbopelvic sagittal balance, but only in the presence of a congruent thoracic curvature.

MATERIALS AND METHODS

After reviewing the literature, published measures made using the PR technique were compared to measures taken from a substantial patient population (479 adult patients).

CONCLUSIONS

Errors can occur using the PR technique if the PRT12 is viewed in isolation from the thoracic kyphosis. We found the ratio of the thoracic kyphosis to lumbar lordosis (T4-T12/T12-S1) to be a useful predictor of congruent sagittal alignment, which may alert the clinician to situations where use of the PR-T12 in isolation may be misleading.

A retrospective review of long anterior fusions to the sacrum

BACKGROUND CONTEXT

In the setting of tumor, infection, or trauma, a corpectomy of the L5 vertebral body may be necessary. However, the space has an irregular trapezoidal shape, and the failure to account for this may lead to improper fitting of the titanium cages or the allograft struts when performing a reconstruction.

PURPOSE

The purpose of this study was to evaluate the failure rate of implants used to reconstruct the anterior lumbar spine when an L5 corpectomy has been performed.

METHODS

A retrospective review of the medical records and radiographs of 19 consecutive patients undergoing an L5 corpectomy and anterior spinal fusion was performed. The radiographs were reviewed for implant failure and successful fusions.

RESULTS

Cases included osteomyelitis (13), fractures (4), and tumor (2). Anterior reconstruction was performed with a straight cylindrical titanium cage in six cases, allograft in six cases, iliac crest bone graft (ICBG) in two cases, and cages with lordosis built into the cage or end plates in five cases. In the six straight cylindrical titanium cages, four cases had displaced anteriorly, necessitating revision surgery. In the other two cases, both had poor fixation to the sacrum and developed nonunions. In the six reconstructed with allograft, all three fibular struts developed nonunions. In the three reconstructed with humeral or femoral allograft, all patients formed a solid fusion. In the patients reconstructed with ICBG, one formed a nonunion, whereas the other one formed a solid fusion. In the cages with lordosis built into the cage or end plates, all five developed solid fusions.

CONCLUSIONS

A corpectomy of L5 resulting in an irregular trapezoidal shape must be accounted for when performing the reconstruction. Use of straight cylindrical cages or allograft with small footprints may lead to an increased rate of failure. When performing the reconstruction, adding approximately 20° to 30° of lordosis to the construct may create a better fit and increase stability and result in an improved fusion rate. If using allograft, using a larger graft with greater end plate contact may also improve fusion rates.

Kinematic analysis of the lumbar spine by digital videofluoroscopy in 18 asymptomatic subjects and 9 patients with herniated nucleus pulposus

OBJECTIVES

The purpose of this study was to use digital videofluoroscopy to identify motion patterns of the lumbar spine during coronal movement in asymptomatic (normal) subjects and patients with herniated nucleus pulposus (HNP).

METHODS

Videofluoroscopic lumbar coronal motion was recorded in 18 asymptomatic volunteers and 9 patients with HNP. Measurements were made while patients bent laterally and rotated toward the right and left from a sitting position and then returned to their original position. Direction and degree of extension in the coronal plane at each motion segment and sacral descent were measured. Through the motion analysis software, the coupled pattern with lateral bending and rotation was analyzed in the asymptomatic subjects and patients with HNP.

RESULTS

Lateral flexion movement was coupled with contralateral extension and ipsilateral sacral descent but with a different rotation pattern. Rotation movement was coupled with ipsilateral extension, ipsilateral sacral descent, and ipsilateral spinous process rotation. Patients with HNP and asymptomatic subjects had similar coupled patterns but differences in amount of motion.

CONCLUSIONS

Digital videofluoroscopy showed coupled patterns during the lateral bending and rotation movements.

Lumbopelvic alignment on standing lateral radiograph of adult volunteers and the classification in the sagittal alignment of lumbar spine

The analysis of the sagittal balance is important for the understanding of the lumbopelvic biomechanics. Results from previous studies documented the correlation between sacro-pelvic orientation and lumbar lordosis and a uniqueness of spino-pelvic alignment in an individual person. This study was subjected to determine the lumbopelvic orientation using pelvic radius measurement technique. The standing lateral radiographs in a standardized standing position were taken from 100 healthy volunteers. The measurements which included hip axis (HA), pelvic radius (PR), pelvic angle (PA), pelvic morphology (PR-S1), sacral translation distance (HA-S1), total lumbosacral lordosis (T12-S1), total lumbopelvic lordosis (PR-T12) and regional lumbopelvic lordosis angles (PR-L2, PR-L4 and PR-L5) were carried out with two independent observers. The relationships between the parameters were as follows. PR-S1 demonstrated positive correlation to regional lumbopelvic lordosis and revealed negative correlation to T12-S1. PA showed negative correlation to PR-S1 and regional lumbopelvic lordosis, but revealed positive correlation to HA-S1. T12-S1 was significantly increased when PR-S1 was lesser than average (35°-45°) and was significantly decreased when PR-S1 was above the average. PR-L4 and PR-L5 were significantly reduced when PR-S1 was smaller than average and only PR-L5 was significantly increased when PR-S1 was above the average. In conclusion, this present study supports that lumbar spine and pelvis work together in order to maintain lumbopelvic balance.

A new look at the geometry of the lumbar spine

STUDY DESIGN

A retrospective cohort study of the relationship between the structures that form the lumbar spine in humans.

OBJECTIVE

To investigate the relationship between the segmental wedging of the vertebral bodies and that of the intervertebral discs, and between the overall lordosis angle and each of the 5 lumbar segments.

SUMMARY OF BACKGROUND DATA

Little attention has been paid to the internal relationship between the structures that form the lumbar spine. Understanding these relationships is instrumental to our ability to restore and rehabilitate the lordotic curvature.

METHODS

Lateral radiographs of 101 adult lumbar spines were examined in patients at spinal clinics. The patients had no history of spinal surgery and no radiographic abnormality. The radiologic parameters are the lordosis angle (LA), the body wedge angle (B), the total segmental angle (S), and the intervertebral disc angle (D). Measurements B, S, and D were taken for each of the 5 lumbar segments. Measurements B and D were used to calculate ΣB, the sum of the B, and ΣD, the sum of the D.

RESULTS

The LA correlates with the sum of the vertebral body angles and with the sum of the intervertebral disc angles. Vertebral body wedging is negatively correlated with intervertebral disc wedging. The middle 3 lumbar segments are moderately-to-poorly correlated, among themselves and with the LA, while the upper and lower lumbar segments are poorly correlated with the LA and not correlated with any lumbar segment.

CONCLUSION

Three parts of the lumbar lordosis were identified: the upper part, formed by the first lumbar segment; the middle part, formed by the middle 3 segments; and the lower part, formed by the fifth lumbar segment. The statistical study shows an inverse relationship between vertebral body and intervertebral disc wedging.

Spinopelvic alignment after interspinous soft stabilization with a tension band system in grade 1 degenerative lumbar spondylolisthesis

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

The purpose of this study was to examine the changes in spinopelvic alignment after interspinous soft stabilization (ISS) with a tension band system and to identify the lumbosacral parameters related to those changes and to determine their impact on the clinical outcomes compared with posterior lumbar interbody fusion (PLIF) in patients with low-grade degenerative spondylolisthesis (DS).

SUMMARY OF BACKGROUND DATA

The sacropelvic morphometric changes after fusion surgery have received much research attention. However, few reports have addressed the issue after use of dynamic or soft stabilization systems.

METHODS

From April 2001 to November 2003, 45 patients presenting with grade 1 DS with stenosis underwent either ISS with a tension band system (ISS group) or PLIF with pedicle screw fixation (PLIF group). The mean follow-up period was 76.8 months. Three pelvic parameters, the sacral slope (SS), pelvic tilt (PT), and pelvic incidence, were investigated to address the sacropelvic morphometric change. Clinical outcomes were assessed using the visual analog scale score, the Oswestry Disability Index, and the patient's satisfaction index.

RESULTS

Both groups showed significant improvements in all of the clinical outcomes, with no significant differences between groups. In the ISS group, the SS increased and PT decreased, whereas in the PLIF group, the SS decreased and PT increased, resulting in pelvic anteversion and retroversion, respectively, with significant intergroup differences in SS and PT (SS: P = 0.047; PT: P = 0.01). The positive association of lumbar lordosis with SS (r = 0.448) and its negative association with PT (r = -0.674) in the respective groups indicate the influence of changes in lumbar lordosis on pelvic positional changes. Significant correlations between follow-up segmental lumbar lordosis and the visual analog scale score for leg pain (r = -0.685) and Oswestry Disability Index score (r = -0.425) were found in the ISS group alone.

CONCLUSION

Segmental lordotic change after ISS with a tension band system was the possible decisive factor in the development of pelvic anteversion while maintaining sagittal lumbar balance; lack of lumbar lordosis led to compensatory pelvic retroversion in the PLIF group. Considering the comparable clinical results with PLIF surgery and the achievement of physiologic sagittal spinopelvic balance, the ISS procedure can be a feasible alternative to fusion surgery in patients with grade 1 DS with stenosis.

Posicionamento da pelve e lordose lombar em mulheres com incontinência urinária de esforço

O objetivo do estudo foi averiguar possível associação do posicionamento da pelve e da lordose lombar com incontinência urinária por esforço (IUE), por meio de análise fotogramétrica e radiográfica, comparando também os resultados dos dois métodos. Vinte mulheres com IUE foram comparadas a 20 mulheres controles, sem IU; de todas foram tiradas fotografias da região pélvica, onde se analisaram a simetria da pelve anterior e posterior, a lordose lombar (LL) e a báscula de pelve (BP). Na radiografia da coluna lombossacra foram mensurados os ângulos de Cobb, o lombossacro e de inclinação sacral. As comparações dos resultados foram tratadas estatisticamente, com nível de significância de 5%. Não foi encontrada diferença significativa na simetria da pelve ou na lordose lombar comparando-se os dois grupos, à exceção do ângulo BP (-3,69 nas incontinentes e -8,18, nas controles), indicando tendência à anteversão pélvica nessas últimas. Dos demais ângulos não houve diferenças entre os grupos, tendo as mulheres com IUE apresentado tantas alterações na pelve quanto as mulheres continentes, sugerindo que a LL e o posicionamento da pelve não influem na IUE. Na comparação dos dados obtidos por radiografia e fotogrametria, no conjunto da amostra, apenas uma fraca correlação foi encontrada entre a medida da lordose lombar por fotogrametria e a do ângulo sacral por radiografia.

The effect of shaped wheelchair cushion and lumbar supports on under-seat pressure, comfort, and pelvic rotation

AIM

A wheelchair seat and position help clients perform daily activities. The comfort of the wheelchair can encourage clients to participate in daily activities and can help prevent future complications.

PURPOSE

This study evaluates how a shaped seat-cushion and two different back supports affect under-seat pressure, comfort, and pelvic rotation.

METHOD

Thirty healthy subjects were tested using two differently equipped manual wheelchairs. One wheelchair had a Velcro adjustable back seat and a plane seat-cushion. The other wheelchair had a non-adjustable sling-back seat and a plane cushion. The second wheelchair was also equipped with a shaped cushion and/or a detachable lumbar support. Under-seat pressure, estimated comfort, and pelvic rotation were measured after 10 min in each wheelchair outfit.

RESULTS

Peak pressure increased with the shaped cushion compared to the plane cushion. No significant difference in estimated comfort was found. Pelvic posterior-rotation was reduced with the adjustable or detachable back-support irrespective of the shape of the seat cushion.

CONCLUSIONS

To support a neutral pelvic position and spinal curvature, a combination of a shaped cushion and a marked lumbar support is most effective.

Thoraco lumbar junction syndrome: A case report

This case report describes a 46-year-old female who experienced symptoms of low back pain with pain radiating into the right gluteal area. Initial intervention addressed mechanical dysfunction at the lumbosacral junction. Reduction in symptoms was observed following manual therapy procedures that addressed the lumbosacral junction; however, the right gluteal pain persisted with recurrence of back pain. Subsequent examination revealed non-neutral dysfunction at the thoracolumbar junction. Treatment was continued with manual therapy procedures that addressed facet restriction and soft tissue dysfunction in the thoracolumbar junction. A marked relief in symptoms was reported thereafter, with a decrease in right gluteal pain and improved functional ability. The anatomical and clinical relevance to this scenario is described. The thoracolumbar junction is described as a predominant contributor to the symptomatology. Its complementary role to the lumbosacral junction is enumerated.

Classification of sagittal thoraco-lumbo-pelvic alignment of the adolescent spine in standing and its relationship to low back pain

STUDY DESIGN

A prospective study of the sagittal standing posture of 766 adolescents.

OBJECTIVE

To determine whether posture subgroups based on photographic assessment are similar to those used clinically and to previous, radiographically determined subgroups of sagittal standing posture, and whether identified subgroups are associated with measures of spinal pain.

SUMMARY OF BACKGROUND DATA

Relatively little research has been performed toward a classification of subjects according to sagittal spinal alignment. Clinical descriptions of different standing posture classifications have been reported, and recently confirmed in a radiographic study. There is limited epidemiological data available to support the belief that specific standing postures are associated with back pain, despite plausible mechanisms. As posture assessment using radiographic methods are limited in large population studies, successful characterization of posture using 2-dimensional photographic images will enable epidemiological research of the association between posture types and spinal pain. METHODS.: Three angular measures of thoraco-lumbo-pelvic alignment were calculated from lateral standing photographs of subjects with retro-reflective markers placed on bony landmarks. Subgroups of sagittal thoracolumbar posture were determined by cluster analysis of these 3 angular measures. Back pain experience was assessed by questionnaire. The associations between posture subgroups and spinal pain variables were evaluated using logistic regression.

RESULTS

Postural subtypes identified by cluster analysis closely corresponded to those subtypes identified previously by analysis of radiographic spinal images in adults and to those described clinically. Significant associations between posture subgroups and weight, height, body mass index, and gender were identified. Those adolescents classified as having non-neutral postures when compared with those classified as having a neutral posture demonstrated higher odds for all measures of back pain, with 7 of 15 analyses being statistically significant.

CONCLUSION

Meaningful classifications exist for adolescent sagittal thoraco-lumbo-pelvic alignment, and these can be determined successfully from sagittal photographs. More neutral thoraco-lumbo-pelvic postures are associated with less back pain.

Orientation of the human sacrum: Anthropological perspectives and methodological approaches

Discovering the nature of sacral orientation is of considerable anthropological importance. Therefore, this study aims at presenting a new anthropologically based definition for sacral anatomical orientation (SAO) angle, establishing standards of SAO for human population; examining the relationship between pelvic incidence (PI) and SAO; and associating SAO with demographic parameters. The study population consisted of 424 adult and 14 sub-adult (13-18 years, for SAO only) pelvises. Sacral orientation was measured using two different definitions: a) SAO is the angle created between the intersection of a line running parallel to the superior surface of the sacrum and a line running between the anterior superior iliac spine (ASIS) and the anterior-superior edge of the symphysis pubis; b) PI is the angle created between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the middle of the axis of the acetabulum. SAO was measured using a specially designed mechanical measurement tool and a 3D digitizer. PI was measured via the 3D digitizer. The methods developed by us for measuring SAO and PI in skeletal material are valid and reliable. SAO and PI measures were highly correlated (r = -0.824, P < 0.001). The average SAO was 49.01 degrees (SD = 10.16), and the average PI 54.08 degrees (SD = 12.64). SAO was independent of ethnicity and sex, yet age dependent. This study establishes a methodology for estimating SAO and PI in skeletal material and furnishes the anthropological milieu with base line data regarding these parameters. Future studies in human evolution can greatly benefit from this study.

The vertical projection of the sum of the ground reactive forces of a standing patient is not the same as the C7 plumb line: a radiographic study of the sagittal alignment of 153 asymptomatic volunteers

STUDY DESIGN

A radiographic study of 153 normal volunteers.

OBJECTIVES

1) To test the hypothesis that the vertical projection of the sum of the ground reactive forces of a standing patient is located in the same place in the sagittal plane as the C7 plumb line; 2) to determine if there are consistent geometric relationships between the location of the top of the spine and the pelvis in the sagittal plane that occur in individuals without symptoms of back pain or radiographic evidence of deformity.

SUMMARY OF BACKGROUND DATA

Defining the optimal state of spinal balance is difficult. A full understanding of the compensatory relationships between the spine, pelvis, and lower limbs remains elusive.

METHODS

A total of 153 normal volunteers were subjected to radiographic examination using a digital force plate, a stabilized standing position, a standardized radiographic technique, and the computerized measurement of sagittal alignment.

RESULTS

1) The C7 plumb line and the gravity line in a stabilized standing position are not located in the same place; 2) the association between the center of T1 and the sacral endplate may be an anatomic constant and a marker of spinal balance in individuals without symptoms of back pain or radiographic evidence of deformity, and is determined by the formula 99 degrees - 0.1 degrees (sacral slope).

CONCLUSIONS

We speculate that this information will be very helpful in evaluating symptomatic spinal disease in the context of the overall alignment of the spine and pelvis.

The femoro-sacral posterior angle: an anatomical sagittal pelvic parameter usable with dome-shaped sacrum

The sagittal pelvic morphology modulates the individual alignment of the spine. Anatomical angular parameters were described as follows: the "Pelvic Incidence" (PI) and the Jackson's angle "Pelvic Lordosis" (PR-S1). Significant chains of relationships were expressed connecting these angles with pelvic and spinal positional parameters. This allows an individual assessment of the harmony of the sagittal spinal balance. But in case of spondylolysis with high-grade listhesis, the upper plate of the sacrum shows a dome-shaped deformity. The previous anatomical parameters are therefore imprecise. Indeed, the anterior part of the sacrum being inaccurate, an exact assessment of these angles becomes impossible. Therefore, we propose a new angular parameter named "Femoro-Sacral Posterior Angle" (FSPA): the angle between the posterior wall of the first sacral vertebra, always well definite, and the line connecting the posterior part of the sacral plate to the femoral axis. The validation of this parameter was performed and compared with the classical published parameters. It showed good inter-observer reliability, even with dome-shaped sacral plate. In spite of lower correlation with the positional parameters than those observed with PI or PR-S1, the FSPA appeared to be reliable and precise for an exact evaluation of the sagittal spino-pelvic balance is case of spondylo-listhesis with dome-shaped sacral endplate.

Spinopelvic alignment in patients with osteoarthrosis of the hip: a radiographic comparison to patients with low back pain

STUDY DESIGN

A retrospective, age- and sex-matched radiographic study.

OBJECTIVES

To investigate the spinopelvic alignment in patients with osteoarthosis of the hip (HOA) and those with low back pain (LBP) and to determine the characteristics and differences in both groups.

SUMMARY OF BACKGROUND DATA

Hip-spine syndrome, first described by Offierski and MacNab, is quite an important pathology when treating patients with pain in their low back and lower extremities. However, despite it being a well-known entity, few papers have adequately investigated and assessed the spinopelvic alignment in patients with hip-spine syndrome.

METHODS

Sagittal and coronal spinopelvic alignments were investigated in 150 patients with HOA and 150 with LBP using radiographs of the whole spine in both anteroposterior and lateral views. Parameters measured in this study were lumbar lordosis (LL), sacral slope (SS), the shift of the sagittal C7 plumb line, pelvic incidence (PI), and pelvic tilt (PT) on the lateral radiographs. On the anteroposterior (AP) films, lumbar scoliosis, pelvic obliquity, leg length discrepancy, the shift of the coronal C7 plumb line, and Sharp angle were measured. These parameters were compared between the two groups. In patients with HOA, the relationships between Sharp angle and other parameters were also analyzed to clarify the possible influence of sagittal and coronal spinopelvic alignments on HOA without acetabular dysplasia.

RESULTS

LL, SS, PI, and PO were found to be less in patients with LBP compared with those with HOA, and there was no significant difference in LS between the two groups. PI was significantly greater in HOA patients and strongly correlated to PT, SS, and LL (i.e., as the PI increased so did the PT, SS, and LL). Sharp angles were also significantly greater in HOA patients and strongly correlated to age, LL and SS (i.e., as Sharp angles increased so did LL and SS); however, age decreased in the hip patients.

CONCLUSIONS

These findings suggest that higher PI in the younger individual may contribute to the development of HOA in later life without both lumbar kyphosis and acetabular dysplasia because of the anterior uncovering of the acetabulum. More investigation will be expected to analyze the spinopelvic alignment in patients with hip spine syndrome.

Effects of Abdominal Postures on Lower Extremity Energetics during Single-Leg Landings

Context:

Functional implications of clinically relevant abdominal postures have been sparsely examined.

Objectives:

To evaluate the reliability of sustaining abdominal postures during single-leg landings and the effects of abdominal postures on lower extremity kinetics and energetics.

Design:

One-way ANOVA tested effects of leg-spring stiffness and lower extremity energetics across groups (control, abdominal hollowing [AH], and pelvic tilting [PT]).

Participants:

12 male (24.0 ± 3.4 years) and 12 female (21.9 ± 2.3 years) healthy, recreationally active subjects.

Main Outcome Measures:

Leg-spring stiffness and relative joint-energy absorption from control, AH, and PT groups.

Results:

AH and PT ICCs2,kand standard error of measurements (AH = 0.53 ± 0.4 cm, PT = 0.9° ± 0.8°) were moderate to high. Relative knee-energy-absorption effect sizes comparing the control and treatment groups revealed moderate treatment effects (AH = 0.66%, PT = 0.41%).

Conclusions:

Abdominal postures can be reliably performed during a single-leg-landing task. Energy-absorption effect sizes suggest a link between the trunk and lower extremity.