Lumbar Segmental Instability Research Articles

201. Utility of neutral sitting lateral radiographs for assessment of lumbar segmental instability in lumbar spondylolisthesis: a prospective study

BACKGROUND CONTEXT Degenerative lumbar spondylolisthesis (DLS) is a common disease and often results in back pain and neurogenic claudication, which frequently requires surgical intervention. However, segmental instability is a key factor in determining the treatment algorithm. PURPOSE To investigate the listhesis of the involved segments in DLS through slump sitting radiograph, and to determine the most useful diagnostic modalities in the evaluation of instability. STUDY DESIGN/SETTING This study prospectively recruited a consecutive series of patients with L4/5 DLS who underwent surgical intervention at our center between September 2018 and January 2019. PATIENT SAMPLE A total of 29 patients (9 men, 20 women), with a mean age of (59.6±8.2) years (3yr) were included. OUTCOME MEASURES Slip parameters were measured on all the sagittal images. Maximal translational and angular range of motion (ROM) was determined by comparing slip parameters between the above radiographs. METHODS All subjects had X-ray studies performed in slump sitting (Si), upright standing (U), flexion (F), extension (E) and supine MRI (Su). Slip parameters were measured on all the sagittal images. Maximal translational and angular range of motion (ROM) was determined by comparing slip parameters between the above radiographs. RESULTS A total of 29 patients (9 men, 20 women), with a mean age of (59.6±8.2) years (3yr) were included. Maximal vertebral reduction could be detected on Si, U and F radiograph, and maximal vertebral reduction could be determined on Su and E radiograph. In all, Si radiograph was detected with the maximal SP and minimum SA (P CONCLUSIONS Si radiograph demonstrated maximal anterior listhesis than U and F radiograph, and minimum intervertebral lordosis than E radiograph. Incorporation of Si lateral radiographs can improve our understanding of segmental mobility when evaluating DLS. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Core Stabilization With the Lumbar Extension Exercise in Low Back Pain

Background: We developed a novel integrative lumbar stabilization technique that combines lumbar extension (LE) exercise with abdominal drawing-in maneuver (ADIM) to ameliorate low back pain (LBP) associated with neuromuscular imbalance and instability, based on the collective evidence of contemporary spinal rehabilitation. Objects: The specific aim of the present study was to investigate the effects of LE exercise with and without ADIM on core muscle strength, lumbar spinal instability, and pain, as well as functional characteristics in individuals with LBP using advanced radiographic imaging techniques. Methods: patients with mechanical LBP (N = 40, 6 males; 35.1±7.6 years) were recruited and randomly assigned either to the combined LE and ADIM (experimental group) or the LE alone (control group). Outcome measures included the visual analog scale, the modified Oswestry Disability Index, muscle strength imbalance (MSI), and radiographic imaging. The lumbar intervertebral displacement (LID), intervertebral (IV) and total lumbar extension (TLE) angles were calculated to evaluate the lumbar segmental instability. Results: The experimental group showed significant differences in the L3-L4, L5-S1 LIDs, L4-L5 and L5-S1 IV angles, and TLE angle as compared to the controls (p<.05). Immediate pain reduction and muscle strength imbalance ratio were significantly different between the groups (p<.05). Conclusion: These results suggest that the addition of ADIM significantly increased lumbar spinal stabilization in individuals with LBP, thereby reducing pain associated with functional lumbar flexion during daily activities.

Utility of Supine Lateral Radiographs for Assessment of Lumbar Segmental Instability in Degenerative Lumbar Spondylolisthesis.

Retrospective chart review OBJECTIVE.: To determine whether supine lateral radiographs increase the amount of segmental instability visualized in single-level lumbar degenerative spondylolisthesis, when compared to traditional lateral flexion-extension radiographs. We hypothesized that supine radiographs increase the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to flexion-extension. Accurate evaluation of segmental instability is critical to the management of lumbar spondylolisthesis. Standing flexion-extension lateral radiographs are routinely obtained, as it is believed to precipitate the forward-backward motion of the segment; however, recent studies with magnetic resonance imaging and computed tomography have shown that the relaxed supine position can facilitate the reduction of the anterolisthesed segment. Here, we show that inclusion of supine lateral radiographs increases the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to traditional lateral radiographs. Supine lateral radiographs were added to the routine evaluation (standing neutral/flexion/extension lateral radiographs) of symptomatic degenerative spondylolisthesis at our institution. In this retrospective study, 59 patients were included. The amount of listhesis was measured and compared on each radiograph: standing neutral lateral ("neutral"), standing flexion lateral ("flexion"), standing extension lateral ("extension"), and supine lateral ("supine"). A total of 59 patients (51 women, 8 men), with a mean age of 63.0 years (±9.85 yr) were included. The mean mobility seen with flexion-extension was 5.53 ± 4.11. The mean mobility seen with flexion-supine was 7.83% ± 4.67%. This difference was significant in paired t test (P = 0.00133), and independent of age and body mass index. Maximal mobility was seen between flexion and supine radiographs in 37 patients, between neutral and supine radiographs in 11 cases, and between traditional flexion-extension studies in 11 cases. Supine radiograph demonstrates more reduction in anterolisthesis than the extension radiograph. Incorporation of a supine lateral radiograph in place of extension radiograph can improve our understanding of segmental mobility when evaluating degenerative spondylolisthesis. 3.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P62. Application of laparoscopic lumbar discectomy and artificial disc replacement: at least two years of follow-up

BACKGROUND CONTEXT Symptomatic degenerative disc disease is the major cause of low back pain with lumbar segmental instability. Artificial disc replacement (ADR) has increased in popularity as an alternative treatment for lumbar disc herniation. However, the traditional approach to spinal surgery carries the risk of catastrophic bleeding from injury to major vessels, as well as iatrogenic injury to the viscera and associated structures. Therefore, laparoscopic lumbar discectomy and ADR may represent a useful alternative. PURPOSE The current study aimed to assess the safety and efficacy of ADR using a laparoscopic technique for lumbar disc herniation. STUDY DESIGN/SETTING This prospective observational study included 22 patients who were diagnosed with symptomatic degenerative disc disease treated via ADR with a laparoscopic technique. PATIENT SAMPLE Twenty-two patients (8 males and 14 females) who were diagnosed with symptomatic degenerative disc disease were included in this study. Seven cases involved the L4/5 level, and 15 cases involved the L5/S1 level. All patients were ineffective after at least 6 months of conservative treatments; all patients were informed of the surgery before the operation and provided consent. OUTCOME MEASURES Three-dimensional computed tomographic angiography (3D-CTA) of the iliac great blood vessels was completed before the surgery. All surgical procedures were performed under a laparoscope. All patients were followed up. METHODS Twenty-two patients (8 males and 14 females) who were diagnosed with symptomatic degenerative disc disease were included in this study. Seven cases involved the L4/5 level, and 15 cases involved the L5/S1 level. All patients were ineffective after at least 6 months of conservative treatments; all patients were informed of the surgery before the operation and provided consent. Three-dimensional computed tomographic angiography (3D-CTA) of the iliac great blood vessels was completed before the surgery. All surgical procedures were performed under a laparoscope. All patients were followed up. RESULTS All surgeries were successfully completed. The average operation time was 120 minutes (range 110–150 minutes), and the average hemorrhage was 145 mL (range 80–360 mL). All cases underwent X-ray imaging at 3days, 3 months, 6 months, 1 year, and the final postoperative follow-up. The outcome indicated that there was no mobilization, displacement, or subsidence in all patients with the exception of one case with prosthesis migration. The follow-up time was 43.8 months (range 24–64 months). The mean visual analog scale (VAS) and Oswestry scores were decreased postoperatively. The mean improvement rate of the VAS score was 73.5%. CONCLUSIONS Lumbar ADR using a laparoscope represents a novel, minimally invasive treatment for symptomatic degenerative disc disease and severe lumbar discogenic pain.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P134. Application of laparoscopic lumbar discectomy and anterior lumbar interbody fusion: at least six years of follow-up

BACKGROUND CONTEXT Symptomatic degenerative disc disease is the major cause of low back pain with lumbar segmental instability. Anterior discectomy and interbody fusion has increased in popularity as an alternative treatment for lumbar disc herniation. However, the traditional approach to spinal surgery carries the risk of catastrophic bleeding from injury to major vessels, as well as iatrogenic injury to the viscera and associated structures. Therefore, laparoscopic lumbar discectomy and interbody fusion may represent a useful alternative. PURPOSE The current study aimed to assess the mid-term safety and efficacy of lumbar discectomy and anterior lumbar interbody fusion (ALIF) using a laparoscopic technique for lumbar disc herniation. STUDY DESIGN/SETTING This prospective observational study included 32 patients who were diagnosed with symptomatic degenerative disc disease treated via lumbar discectomy and ALIF with a laparoscopic technique. PATIENT SAMPLE Thirty-two patients (12 males and 20 females) who were diagnosed with symptomatic degenerative disc disease were included in this study. Four cases involved the L4/5 level, and 28 cases involved the L5/S1 level. All patients were ineffective after at least 6 months of conservative treatments; all patients were informed of the surgery before the operation and provided consent. OUTCOME MEASURES All patients were followed up for more than 6years, X-ray and CT were reviewed regularly to evaluate the height change of intervertebral space and the fusion of bone graft. The clinical effects of preoperative, postoperative and follow-up were evaluated by VAS score, and the complications of laparoscopic surgery were observed. METHODS Thirty-two patients (12 males and 20 females) who were diagnosed with symptomatic degenerative disc disease were included in this study. Four cases involved the L4/5 level, and 28 cases involved the L5/S1 level. All patients were ineffective after at least 6 months of conservative treatments; all patients were informed of the surgery before the operation and provided consent. Three-dimensional computed tomographic angiography (3D-CTA) of the iliac great blood vessels was completed before the surgery. All surgical procedures were performed under a laparoscope. All patients were followed up for more than 6years, X-ray and CT were reviewed regularly to evaluate the height change of intervertebral space and the fusion of bone graft. The clinical effects of preoperative, postoperative and follow-up were evaluated by VAS score, and the complications of laparoscopic surgery were observed. RESULTS All surgeries were successfully completed. All cases were followed up for more than 6years, the average follow-up time was 9years (range 6–12 years). All cases got bone fusion, the average time was 4.5 months (range 3–12 months). The mean VAS were decreased postoperatively, The VAS score of low back pain for preoperative, postoperative (1 week) and final follow-up was 5.8±1.1, 1.8±0.7, 0.9±0.7, the change were statistically significant (p .05). The outcome indicated that there was no mobilization, displacement or intestinal adhesion in all patients in the mid-term follow-up. CONCLUSIONS Laparoscopic lumbar discectomy and ALIF is an effective treatment for severe degenerative lumbosacral diseases

Reoperation rates and risk factors for revision 4 years after dynamic stabilization of the lumbar spine

Background ContextThe concept of dynamic stabilization (DS) of the lumbar spine for treatment of degenerative instability has been introduced almost two decades ago. Dynamic stabilization follows the principle of controlling movement in the coronal plane by providing load transfer of the spinal segment without fusion and, at the same time, reducing side effects such as adjacent segment disease (ASD). So far, only little is known about revision rates after DS due to ASD and screw loosening (SL). PurposeThe present study aimed to evaluate the longitudinal revision rates following dynamic pedicle screw stabilization in the lumbar spine and to determine specific risk factors predictive for ASD, SL, and overall reoperation in a large cohort with considerable follow-up. DesignWe carried out a post hoc analysis of a prospectively collected database in a level I spine center. Patients ExampleThe patient sample comprised 283 (151 female/132 male) consecutive patients suffering from painful degenerative lumbar segmental instability with or without spinal stenosis who underwent DS of the lumbar spine (Ulrich Cosmic, Ulrich Medical, Ulm, Germany) between January 2008 and December 2011. Outcome MeasuresLongitudinal reoperation rate and risk factors predictive for revision surgery were evaluated. MethodsWe analyzed the longitudinal reoperation rate due to ASD and SL and overall reoperation. Risk factors such as age, gender, body mass index, lumbar lordosis (LL), number of segments, and number of previous surgeries were taken into account. Regular and mixed model logistic regressions were performed to determine risk factors for revision surgery on a patient and on a screw level. ResultsThe mean age was 65.7±10.2 years (range 31–88). One hundred thirty-two patients were stabilized in 1 segment, 134 in 2 segments, 15 in 3 segments, and 2 patients in 4 segments. Reoperation rate for ASD and SL after 1 year was 7.4 %, after 2 years was 15.0%, and after a mean follow-up of 51.4±15 months was 22.6%. Reasons for revision were SL in 19 cases (6.6%), ASD in 39 cases (13.7%), SL and ASD in 6 cases, hematoma in 2 cases (0.7%), cerebrospinal fluid fistulae in 3 cases (1.1%), infection in 6 cases (2.1%), and implant failure in 1 case (0.4%). The patients' age, the number of stabilized segments, and the number of previous surgeries and postoperative LL had a significant influence on the probability for revision surgery. ConclusionsReoperation rates after DS of the lumbar spine are comparable with rigid fixations. The younger the patient and the more segments are involved, the lower the LL and the more previous surgeries were found, the higher was the risk of revision. Risk of revision was almost twice as high in men compared with women. We therefore conclude that for clear clinical indication and careful evaluation of preoperative imaging data, DS using the Cosmic system seems to be a possible option. The presented data will help to further tailor indication and patient selection.

Outcome of transforaminal lumbar interbody fusion in spondylolisthesis—A clinico-radiological correlation

IntroductionLumbar spondylolisthesis is a common cause of morbidity in middle aged individuals. Spinal fusion with instrumentation has become the gold standard for lumbar segmental instability. Studies which correlate the improvement in radiology postoperatively with functional outcome show contrasting reports. This study is aimed at finding the correlation between clinical and radiological outcomes after surgery with transforaminal lumbar interbody fusion. MethodsA retrospective study in 35 patients who underwent transforaminal lumbar interbody fusion in a period of 1 year was done. Preoperative pain (VAS Score), functional ability (ODI), radiological parameters (slip angle, slip grade, disc height, foraminal height, lumbar lordosis) were compared with postoperative recordings at the last followup. Functional improvement (Macnab’s criteria) and fusion (Lee’s fusion criteria) were assessed. Statistical analysis was done with student’s paired t-test and Pearson’s correlation coefficient. ResultsVAS score, ODI improved from 8 to 2 and 70 to 15 respectively. Slip angle improved from 23°to 5° on an average. 80% patients showed fusion and 85% showed good clinical outcome at 1 year followup. Analyzing with Pearson correlation coefficient showed no significant relation between pain scores and radiological parameters. But there was statistically significant relation between radiological fusion and the final clinical outcome. ConclusionTLIF produces spinal fusion in most individuals. Strong spinal fusion is essential for good clinical outcome in spondylolisthesis patients who undergo TLIF. Reduction in slip is not necessary for all patients with listhesis.

Spontaneous Spinal Arthrodesis in Stand-Alone Percutaneous Pedicle Screw Fixation Without in Situ Fusion in Patients With Lumbar Segmental Instability: Long-Term Clinical, Radiologic, and Functional Outcomes.

No study to date has established how commonly spontaneous fusion occurs after stand-alone percutaneous pedicle screw fixation in adult population. In this retrospective single-center study, we investigated the effectiveness, long-term solidity and safety of stand-alone percutaneous pedicle screw fixation without in situ fusion and the influence of presence or absence of fusion on the clinical outcome of patients with low-grade lumbar segmental instability. Eighty-eight patients with symptomatic low-grade spondylolisthesis were treated with posterior stand-alone percutaneous pedicle screw fixation without bone graft. Radiographic evaluation was used to determine if spontaneous fusion or absence of fusion was present. The solid fusion and absence of fusion groups were analyzed clinically (visual analog scale and Oswestry Disability Index) and with a validated self-administered questionnaire. The average duration of follow-up was 70.5 months (range, 48-120 months). Radiologic signs of spontaneous fusion were present in 45.5% of the cohort and absent in 54.5%. Clinical outcome was excellent to good in 73.8% of the cohort (in 70.9% of cases with spontaneous fusion and in 67.5% of cases with absence of fusion). No significant differences in visual analog scale scores for residual back and lower limb pain between the 2 groups were seen at the final follow-up. At the final follow-up, 5 of 88 patients (5.6%) underwent revision surgery. Percutaneous pedicle screw fixation offers several advantages that help minimize approach-related morbidity, while achieving similar clinical outcome as seen with more traditional invasive procedures. A solid fixation without bone graft provides long-term clinical benefits. In our patients, the appearance of a spontaneous solid fusion and the absence of fusion after stand-alone pedicle screw fixation were correlated with similar improved clinical outcomes at long-term follow-up.

Efficacy of Lumbar Segmental Stabilization Exercises and Breathing Exercises on Segmental Stabilization in Lumbar Instability Patients

Purpose: The aim of this study was to determine the effectiveness of breathing exercises and lumbar seg-mental exercises on the segmental stability of patients with chronic back pain. Methods: Fifty-nine patients, who suffered from chronic low back pain, were enrolled in this examination. They were divided randomly into three groups: experiment group 1 underwent breathing and segmental stabilization exercises (n=20), experiment group 2 experi-enced segmental stabilization exercises (n=20), and the control group was given the modality treatment (n=19). The measurements were assessed through an Oswestry disability questionnaire (ODQ), as well as a lumbar segmental instability test (LSIT). Results: The ODQ results for experimental groups 1 and 2 were similar (p 0.05). The differences in segmental instability of each of the three groups were similar (p<0.05), and also similar among the three groups (p<0.05). Conclusion: These findings suggest that lumbar segmental stabilization exercises are efficient in increasing the segmental stability and alleviating pain in patients with chronic back pain. Additional studies on this subject will be needed to improve the clinical applications in the future.

MRI findings of lumbar spine instability in degenerative spondylolisthesis.

To find out the factors suggesting lumbar segmental instability in patients with degenerative spondylolisthesis (DS) on conventional magnetic resonance imaging (MRI). Ninety-four patients with DS who underwent decompression surgery with or without fusion were selected. Patient demographics and findings on simple radiographs and MRI were analyzed. We divided patients into two groups by the presence of lumbar instability on simple standing plain radiographs and measured degeneration status of intervertebral discs and facet joints and distance of facet fluid signal on T2 axial MRI on each groups. The data were analyzed to find out the correlation between facet fluid signal and lumbar instability. Sixty-three patients were confirmed to have lumbar instability (unstable group (UG), 67%), while 31 patients (stable group (SG), 33%) did not have instability on simple radiographs. The mean age was slightly older in SG ( p < 0.05) and SG patients' degeneration status of intervertebral discs and facet joints was advanced than UG patients. Fifty-five of 63 patients had high signal intensity on T2-weighted MR images in the UG, but only 4 of 31 patients had high signal intensity in the SG ( p < 0.001) and UG patients have more larger facet joint distance than SG patients ( p < 0.001). High signal in facet joints on T2 MR images can be a useful factor suggestive of lumbar instability. Thus, the identification of fluid signal in the facet joints on MRI should raise the suspicion for lumbar instability and prompt additional evaluations such as with stress radiographs.

Perspective of Lumbar Segmental Instability for Surgical Evalua tion of Lumbar Disc Herniation

Surgery of lumbar disc herniation is most common procedure in neurosurgical practice. However poor outcomes, recurrent disc herniation and recurrence of low back and leg pain which affect quality of life, are still challenging. Lumbar spine instability develops as a result of a gradual degenerative process and lumbar segmental instability is one of main reason of failed back surgery. Presence of lumbar segmental instability or potential secondary instability after surgery should not be overlooked. Accurate preoperative evaluation of patients with lumbar disc herniation needs to understand biomechanics of spinal stability and predict possible result of postoperative instability. Thus failure of treatment modalities can be avoided.

Application of Laparoscopic Lumbar Discectomy and Artificial Disc Replacement: At Least Two Years of Follow-Up.

This prospective observational study included 22 patients who were diagnosed with symptomatic degenerative disc disease treated via artificial disc replacement (ADR) with a laparoscopic technique. The current study aimed to assess the safety and efficacy of ADR using a laparoscopic technique for lumbar disc herniation. Symptomatic degenerative disc disease is the major cause of low back pain with lumbar segmental instability. ADR has increased in popularity as an alternative treatment for lumbar disc herniation. However, the traditional approach to spinal surgery carries the risk of catastrophic bleeding from injury to major vessels, as well as iatrogenic injury to the viscera and associated structures. Therefore, laparoscopic lumbar discectomy and ADR may represent a useful alternative. Twenty-two patients (8 males and 14 females) who were diagnosed with symptomatic degenerative disc disease were included in this study. Seven cases involved the L4/5 level, and 15 cases involved the L5/S1 level. All patients were ineffective after at least 6 months of conservative treatments; all patients were informed of the surgery before the operation and provided consent. Three-dimensional computed tomographic angiography (3D-CTA) of the iliac great blood vessels was completed before the surgery. All surgical procedures were performed under a laparoscope. All patients were followed up. All surgeries were successfully completed. The average operation time was 120 minutes (range 110-150 min), and the average hemorrhage was 145 mL (range 80-360 mL). All cases underwent X-rays at 3 days, 3 months, 6 months, 1 year, and the final postoperative follow-up. The outcome indicated that there was no mobilization, displacement, or subsidence in all patients with the exception of one case with prosthesis migration. The follow-up time was 43.8 months (range 24-64 months). The mean visual analog scale (VAS) and Oswestry scores were decreased postoperatively. The mean improvement rate of the VAS score was 73.5%. Lumbar ADR using a laparoscope represents a novel, minimally invasive treatment for symptomatic degenerative disc disease and severe lumbar discogenic pain.

Analysis of the Relationship between Ligamentum Flavum Thickening and Lumbar Segmental Instability, Disc Degeneration, and Facet Joint Osteoarthritis in Lumbar Spinal Stenosis.

Study DesignCross-sectional study.PurposeTo investigate the relationship between ligamentum flavum (LF) thickening and lumbar segmental instability and disc degeneration and facet joint osteoarthritis.Overview of LiteraturePosterior spinal structures, including LF thickness, play a major role in lumbar spinal canal stenosis pathogenesis. The cause of LF thickening is multifactorial and includes activity level, age, and mechanical stress. LF thickening pathogenesis is unknown.MethodsWe examined 419 patients who underwent computed tomography (CT) myelography and magnetic resonance imaging after complaints of clinical symptoms. To investigate LF hypertrophy, 57 patients whose lumbar vertebra had normal disc heights at L4–5 were selected to exclude LF buckling as a hypertrophy component. LF thickness, disc space widening angulation in flexion, segmental angulation, presence of a vacuum phenomenon, and lumbar lordosis at T12–S1 were investigated. Disc and facet degeneration were also evaluated. Facet joint orientation was measured via an axial CT scan.ResultsThe mean LF thickness in all patients was 4.4±1.0 mm at L4–5. There was a significant correlation between LF thickness and disc degeneration; LF thickness significantly increased with severe disc degeneration and facet joint osteoarthritis. There was a tendency toward increased LF thickness in more sagittalized facet joints than in coronalized facet joints. Logistic regression analysis showed that LF thickening was influenced by segmental angulation and facet joint osteoarthritis. Patient age was associated with LF thickening.ConclusionsLF hypertrophy development was associated with segmental instability and severe disc degeneration, severe facet joint osteoarthritis, and a sagittalized facet joint orientation.

Analysis of the Relationship between Hypertrophy of the Ligamentum Flavum and Lumbar Segmental Motion with Aging Process

Study DesignRetrospective cross-sectional study.PurposeTo investigate the relationship between ligamentum flavum (LF) hypertrophy and lumbar segmental motion.Overview of LiteratureThe pathogenesis of LF thickening is unclear and whether the thickening results from tissue hypertrophy or buckling remains controversial.Methods296 consecutive patients underwent assessment of the lumbar spine by radiographic and magnetic resonance imaging (MRI). Of these patients, 39 with normal L4–L5 disc height were selected to exclude LF buckling as one component of LF hypertrophy. The study group included 27 men and 12 women, with an average age of 61.2 years (range, 23–81 years). Disc degeneration and LF thickness were quantified on MRI. Lumbar segmental spine instability and presence of a vacuum phenomenon were identified on radiographic images.ResultsThe distribution of disc degeneration and LF thickness included grade II degeneration in 4 patients, with a mean LF thickness of 2.43±0.20 mm; grade III in 10 patients, 3.01±0.41 mm; and grade IV in 25 patients, 4.16±1.12 mm. LF thickness significantly increased with grade of disc degeneration and was significantly correlated with age (r=0.55, p<0.01). Logistic regression analysis identified predictive effects of segmental angulation (odds ratio [OR]=1.55, p=0.014) and age (OR=1.16, p=0.008).ConclusionsAge-related increases in disc degeneration, combined with continuous lumbar segmental flexion-extension motion, leads to the development of LF hypertrophy.

Intervertebral Disc Changes after Vertebral Distraction Performed During Posterolateral Spine Fusion for Lumbar Segmental Instability

Analysis of intervertebral disc regeneration after disc height restoration by posterolateral spinal fusion with lumbar distraction of 68 patients diagnosed with degenerative lumbar instability.

Construct validity of center of rotation in differentiating of lumbar segmental instability patients.

Lumbar Segmental Instability (LSI) is a subgroup of nonspecific Low Back Pain (NSLBP) without any accepted diagnostic tool as a gold standard. Some authors emphasize on quality measure such as centre of rotation (COR) but construct validity of this measure had not been approved. Therefore the purpose of the present study was to evaluate Concurrent and Convergent validity of COR in differentiating LSI. A total of 66 volunteered males participated in three groups named control, NSLBP and LSI groups based on clinical examination. Patients were diagnosed as LSI according to screening criteria adopted by Hicks et al. Study variables included CORs of lumbar segments in sagittal plane. Three x-rays were taken in neutral, flexion and extension positions. The variables were calculated using CARA software. The ANOVA and Tukey test were utilized in statistic analysis. ANOVA results demonstrated mean differences between three groups for COR of L4 motion segment in y axis (p= 0/008) and L5 motion segment in y axis (p= 0/005) were significant. Tukey test showed significant difference for COR of L4 motion segment in y axis between LSI and healthy groups (p= 0/038) and between LSI and NSLBP groups (p= 0/009). For COR of L5 motion segment in y axis, tukey test demonstrated mean difference between LSI and healthy groups (p= 0/028) and between LSI and NSLBP groups (p= 0/007) were significant. Tukey test did't show any significant difference between NSLBP and healthy groups for COR of L4 (p= 0/852) and L5 (p= 0/871) motion segments in y-axis. The COR has ability to differentiate patients with signs and symptoms of LSI from other NSLBP and healthy subjects based on the present study results. However, more researches are needed to develop and support results of this study.

Comparison of Lumbopelvic Rotation Angle during Active Straight Leg Raise in Patients with Chronic Low Back Pain with and without Lumbar Segmental Instability

PURPOSE: This study aimed to compare the degree of lumbopelvic rotation during the active straight leg raise (ASLR) test in chronic low back pain with and without lumbar segmental instability. METHODS: A total of 71 patients with chronic low back pain were recruited for this study. The subjects who tested positive for more than three of the five lumbar segmental instability tests (prone lumbar instability, lumbar passive extension test, anterior posterior mobility test, passive straight leg raise, age) were categorized into the lumbar segmental instability positive group. Patients who tested positive for less than three of the five tests were categorized into the lumbar segmental instability negative group. The lumbopelvic rotation was measured three times during ASLR and a mean was determined. Subjective heaviness during the ASLR was measured on 6 point scale. RESULTS: There was a statistically significant difference in the lumbopelvic rotation angle between the groups with and without lumbar segmental instability (p, and in the positive and negative groups, respectively (p, the sensitivity was 82.9%, and the specificity was 80.6%. CONCLUSION: These results suggest that lumbopelvic rotation is more prevalent in patients without lumbar segmental instability. Clinically, this important when diagnosing chronic low back pain with lumbar segmental instability, as the lumbopelvic rotation angle during the ASLR test can be used to aid in diagnosis.

Attainment rate as a surrogate indicator of the intervertebral neutral zone length in lateral bending: an in vitro proof of concept study.

BackgroundLumbar segmental instability is often considered to be a cause of chronic low back pain. However, defining its measurement has been largely limited to laboratory studies. These have characterised segmental stability as the intrinsic resistance of spine specimens to initial bending moments by quantifying the dynamic neutral zone. However these measurements have been impossible to obtain in vivo without invasive procedures, preventing the assessment of intervertebral stability in patients. Quantitative fluoroscopy (QF), measures the initial velocity of the attainment of intervertebral rotational motion in patients, which may to some extent be representative of the dynamic neutral zone. This study sought to explore the possible relationship between the dynamic neutral zone and intervertebral rotational attainment rate as measured with (QF) in an in vitro preparation. The purpose was to find out if further work into this concept is worth pursuing.MethodThis study used passive recumbent QF in a multi-segmental porcine model. This assessed the intrinsic intervertebral responses to a minimal coronal plane bending moment as measured with a digital force guage. Bending moments about each intervertebral joint were calculated and correlated with the rate at which global motion was attained at each intervertebral segment in the first 10° of global motion where the intervertebral joint was rotating.ResultsUnlike previous studies of single segment specimens, a neutral zone was found to exist during lateral bending. The initial attainment rates for left and right lateral flexion were comparable to previously published in vivo values for healthy controls. Substantial and highly significant levels of correlation between initial attainment rate and neutral zone were found for left (Rho = 0.75, P = 0.0002) and combined left-right bending (Rho = 0.72, P = 0.0001) and moderate ones for right alone (Rho = 0.55, P = 0.0012).ConclusionsThis study found good correlation between the initial intervertebral attainment rate and the dynamic neutral zone, thereby opening the possibility to detect segmental instability from clinical studies. However the results must be treated with caution. Further studies with multiple specimens and adding sagittal plane motion are warranted.

The inter-rater reliability of clinical tests that best predict the subclassification of lumbar segmental instability: structural, functional and combined instability

Objectives:This study investigated the inter-rater reliability of three structural end range lumbar segmental instability tests with the highest positive likelihood ratio (+ LR) against flexion–extension radiographs, and three functional mid-range clinical tests that predict the success of lumbar stabilisation exercises in patients with recurrent or chronic low-back pain (R/CLBP). The study also investigated the reliability of lumbar segmental instability, subclassification as: functional, structural and combined instability.Method:Forty adults with R/CLBP (30 men and 10 women), aged 21–71 years, underwent repeated measurements of specific clinical tests for structural or functional lumbar segmental instability.Results:All functional-instability tests: the prone instability test (PIT), the aberrant motion test and the average passive straight-leg raise (PSLR>91°) test showed a high percentage agreement (90, 97·5 and 95%, respectively) and a high kappa coefficient (0·71, 0·79 and 0·77, respectively). In addition, two structural tests: the lumbar flexion range of motion (ROM) >53° and the passive lumbar extension test (PLET) showed a high percentage agreement (82 and 73%, respectively), and a moderate kappa coefficient (0·48 and 0·46, respectively). The lack of hypomobility with the posteroanterior (PA) glide test was found to be unreliable (agreement = 25%; k = − 0·02). Locating the pain-provoking segment, as the first portion of PIT, was found to be moderately reliable (k = 0·41). The subclassification categories of lumbar segmental instability (functional, structural and combined) were found to be significantly reliable (PABAK) 0·90, 0·70 and 0·95, respectively).Discussion:All investigated tests (except the lack of hypomobility with the PA glide test), in addition to subclassifying the categories of lumbar segmental instability, were significantly reliable in the assessment of lumbar instability.

EMG activity and force during prone hip extension in individuals with lumbar segmental instability

The goal of the current study was to investigate potential differences in back and hip extensor muscle activity and hip extension force during prone hip extension (PHE) in individuals with lumbar segmental instability (LSI) and asymptomatic subjects. Thirty-six subjects with LSI and 26 asymptomatic volunteers participated in this study. Muscle activity of the erector spinae, gluteus maximus, and biceps femoris was recorded using electromyography (EMG), and hip extension force was measured by a digital force gauge. Muscle activity was significantly greater in subjects with LSI than in asymptomatic subjects during PHE (p < 0.05). Hip extension force was significantly lower in the subjects with LSI than in asymptomatic subjects during PHE (p < 0.05). These findings suggest that during PHE, subjects with LSI have differences in back and hip extensor muscle activity and hip extension force compared to asymptomatic individuals.