S1 Spinous Processes Research Articles

Prospective 5-year follow-up of L5-S1 versus L4-5 midline decompression and interspinous-interlaminar fixation as a stand-alone treatment for spinal stenosis compared with laminectomies.

Spinal stenosis treatment includes laminectomies with or without fusion or with interspinous distraction with or without fixation. Lack of published data on interspinous fixation devices (IFD) at L5-S1 is less considered as an option due to the smaller anatomical S1 spinous process and the higher stresses from the immobile sacrum. Our objective was to evaluate the outcomes of an IFD used as a stand-alone treatment for spinal stenosis at L5-S1 and L4-5 compared to historical data on open laminectomies. Prospective comparative cohort study (Level 2) looking at collected preoperatively and postoperatively Visual Analog Scores (VAS) and Oswestry Disability Index (ODI) data, complications, and revision rates on 100 consecutive patients with spinal stenosis treated with midline decompression and InSpan (InSpan LLC, Malden, MA, USA) IFD, at L5-S1 and L4-5, up to five-year follow-up. All patients were treated by a single surgeon in an academic private practice. Historical published outcome data for open laminectomies were compared. Among the 100 patients, 45 underwent surgery at L5-S1 with a mean VAS pain score that decreased by 75% and ODI improved by 63% (P<0.001). Fifty-five patients had surgery at L4-5 with mean VAS and ODI scores improved by 80% and 66% (P<0.001) respectively. Preoperative and postoperative ODI and preoperative VAS scores were similar at L5-S1 and L4-5, however, postoperative VAS scores were significantly less for L4-5 versus L5-S1 (P<0.01). All surgeries were completed in less than one hour. There was a total of one L4-5 revision (1.8%) and two L5-S1 revisions (4.4%). Comparable laminectomy data showed decrease in VAS and ODI scores by 51% and 62% (P<0.05). The reoperation rate for laminectomies at five to ten years varied up to 24%. Spinal stenosis patients treated with midline decompression and InSpan IFD, used as a stand-alone treatment for interspinous-interlaminar fixation, at L4-5 and L5-S1, showed improved outcome scores and low complication and revision rates at five years and were comparable to historical open laminectomy data. InSpan is a successful substitute for laminectomies in selected patients and was performed in less than 60 minutes. We recommend choosing the appropriately sized implant to achieve adequate distraction decompression to avoid recurrent symptoms.

Evaluation of intraoperative coronal alignment using a computer-assisted rod bending system (CARBS) without intraoperative radiation exposure in adult spinal deformity surgery: a technical note and preliminary results.

Intraoperative radiographs and fluoroscopy are used in adult spinal deformity (ASD) surgery to prevent postoperative coronal malalignment but with limited accuracy. Therefore, we applied a computer-assisted rod bending system (CARBS: Bendini®) for an intraoperative coronal alignment evaluation. The purpose of this study is to introduce this novel technique and validate its accuracy. Fifteen ASD patients were included in the study. The heads of the bilateral S1 pedicle screws (S1), the S1 spinous process, and the bilateral greater trochanter (GT) and the C7 spinous process were recorded with CARBS for an intraoperative coronal alignment evaluation. The lines which connect the bilateral S1 and GT were used as references. The C7-center sacral vertical line (C7-CSVL) on the CARBS monitor was checked, and the C7-CSVL from the intraoperative CARBS recording and postoperative standing whole spine radiograph were compared. Intraoperative C7-CSVL with CARBS was 35.1 ± 31.6mm when the S1 pedicle screws were used as the reference line and was 16.6 ± 17.8mm when the GTs were used. Postoperative C7-CSVL by radiograph was 15.1 ± 16.5mm. In addition, the intraoperative C7-CSVL with CARBS and the postoperative C7-CSVL showed a strong positive correlation in both GT (R = 0.86, p < 0.01) and in S1(R = 0.79, p < 0.01), with a better correlation found in GT than in S1. Intraoperative C7-CSVL with CARBS was found to be highly accurate in ASD surgery. Our results suggest that this novel technique can be useful as an alternative to intraoperative radiography and fluoroscopy and may reduce radiation exposure.

Impact of an intraoperative coronal spinal alignment measurement technique using a navigational tool for a 3D spinal rod bending system in adult spinal deformity cases.

In corrective spinal surgery for adult spinal deformity (ASD), the focus has been on achieving optimal spinopelvic alignment. However, the correction of coronal spinal alignment is equally important. The conventional intraoperative measurement methods currently used for coronal alignment are not ideal. Here, the authors have developed a new intraoperative coronal alignment measurement technique using a navigational tool for a 3D spinal rod bending system (CAMNBS). The purpose of this study was to test the feasibility of using the CAMNBS for coronal spinal alignment and to evaluate its usefulness in corrective spinal surgery for ASD. In this retrospective cohort study, patients with degenerative lumbar kyphoscoliosis, a Cobb angle ≥ 20°, and lumbar lordosis ≤ 20° who had undergone corrective surgery (n = 67) were included. The pelvic teardrops on both sides, the S1 spinous process, the central point of the apex, a point on the 30-mm cranial (or caudal) side of the apex, and the central point of the upper instrumented vertebra (UIV) and C7 vertebra were registered using the CAMNBS. The positional information of all registered points was displayed as 2D figures on a monitor. Deviation of the UIV plumb line from the central sacral vertical line (UIV-CSVL) and deviation of the C7 plumb line from the CSVL (C7-CSVL) were measured using the 2D figures. Nineteen patients evaluated using the CAMNBS (BS group) were compared with 48 patients evaluated using conventional intraoperative radiography (XR group). The UIV-CSVL measured intraoperatively using the CAMNBS was compared with that measured using postoperative radiography. The prevalence of postoperative coronal malalignment (CM) and the absolute value of postoperative C7-CSVL were compared between the groups on radiographs obtained in the standing position within 4 weeks after surgery. Postoperative CM was defined as the absolute value of C7-CSVL ≥ 30 mm. Further, the measurement time and amount of radiation exposure were measured. No significant differences in demographic, sagittal, and coronal parameters were observed between the two groups. UIV-CSVL was 2.3 ± 9.5 mm with the CAMNBS and 1.8 ± 16.6 mm with the radiographs, showing no significant difference between the two methods (p = 0.92). The prevalence of CM was 2/19 (10.5%) in the BS group and 18/48 (37.5%) in the XR group, and absolute values of C7-CSVL were 15.2 ± 13.1 mm in the BS group and 25.0 ± 18.0 mm in the XR group, showing statistically significant differences in both comparisons (p = 0.04 and 0.03, respectively). The CAMNBS method required 3.5 ± 0.9 minutes, while the conventional radiograph method required 13.3 ± 1.5 minutes; radiation exposure was 2.1 ± 1.1 mGy in the BS group and 2.9 ± 0.6 mGy in the XR group. Statistically significant differences were demonstrated in both comparisons (p = 0.0002 and 0.03, respectively). From this study, it was evident that the CAMNBS did not increase postoperative CM compared with that seen using the conventional radiographic method, and hence can be used in clinical practice.

Wrist, but Not Back, Isometric Contraction Induced Widespread Hypoalgesia in Healthy Participants.

Objective: Exercise may reduce pain sensitivity. This phenomenon called exercise-induced hypoalgesia is observed in different types of exercises and involves the activation of endogenous pain modulation systems. Although the effect of limb exercise on pain sensitivity has often been tested, few studies explored the impact of back exercises that are often used to treat low back pain. The main objective is to measure the effect of back-muscle exercise on pain sensitivity and compare it to the effect of a limb-muscle exercise.Methods: Twenty-three participants who were pain-free performed a 4-min wrist flexion isometric contraction followed by a 4-min low back extension, separated by a 20-min break. Pressure pain thresholds were tested at two low back (S1 spinous process, lumbar erector spinae muscle) and two wrist (capitate bone, wrist flexor muscles) sites before and after each exercise. For each exercise, sites were considered as remote or local in relation to the muscles contracted during the exercise. An independent sample of 11 participants was recruited to confirm the influence of low back extension on pain sensitivity.Results: Wrist exercise induced a larger increase in pain sensitivity than back exercise at the remote site. Only wrist exercise induced a hypoalgesia effect at both the local and the remote sites. Back exercise induced a similar effect in the independent sample.Conclusions: This study showed that back and wrist exercises induced a distinct effect on pain sensitivity in participants who were pain-free. The wrist exercise induced a systemic reduction in pain sensitivity (locally and remotely), whereas the back exercise did not. This differential effect may be present because wrist exercise induced most fatigue compared with the back exercise.

Validity and reliability of innovative field measurements of tibial accelerations and spinal kinematics during cricket fast bowling

The use of inertial sensors in fast bowling analysis may offer a cheaper and portable alternative to current methodologies. However, no previous studies have assessed the validity and reliability of such methods. Therefore, this study aimed to assess the validity and reliability of collecting tibial accelerations and spinal kinematics using inertial sensors during in vivo fast bowling. Thirty-five elite male fast bowlers volunteered for this study. An accelerometer attached to the skin over the tibia was used to determine impacts and inertial sensors over the S1, L1 and T1 spinous processes used to derive the relative kinematics. These measurements were compared to optoelectronic and force plate data for validity analysis. Most acceleration and kinematics variables measured report significant correlations > 0.8 with the corresponding gold standard measurement, with intraclass correlation coefficients greater than 0.7. Low standard error of measurement and consequently small minimum detectable change (MDC) values were also observed. This study demonstrates that inertial sensors are as valid and reliable as current methods of fast bowling analysis and may provide some advantages over traditional methods. The novel metrics and methods described in this study may aid coaches and practitioners in the design and monitoring of fast bowling technique.Graphical abstractGraphical abstract illustrating the synopsis of the findings from this paper.

Familial occurrence of skeletal developmental anomalies as a reflection of biological relationships in a genealogically documented Central European sample (19th to 20th centuries).

Skeletal developmental anomalies (SDA) are a subject of constant interest across scientific disciplines, but still mostly as isolates and curiosities. The aim of this study was to find out to what extent the occurrence of SDA reflects documented biological relationships. The skeletal remains of 34 individuals with known genealogical data were available, members of one family over four generations (19th to 20th centuries, Bohemia, Czech Republic), including some inbred individuals. The occurrence of 89 SDA was assessed on the basis of scopic morphological evaluation and X-ray and CT examinations. The degree of similarity between individuals was calculated using a "similarity coefficient" (SC). A linear model was used to test the relationship between positive values of the SC and the relatedness of biologically related individuals. Simultaneously, based on population frequencies of the evaluated anomalies, those that could be considered familial were recorded. A statistically significant relationship between morphological similarity and the biological distance between individuals was found. The greatest similarity was found among close relatives such as parents and children, siblings, or grandparents and grandchildren. The effect of increased consanguinity on the occurrence of anomalies was not confirmed, however. Seventeen SDA shared by closely related individuals were found in the sample, supporting the documented family relationships among them. Eleven of these were selected as possibly familial, but only five were statistically significant: an elongated styloid process, a cervical block vertebrae (arch, facet joints), hamate hamulus aplasia, anteater nose sign, and incomplete fusion of the S1spinous process. There were also 28 cases of individual occurrences of 17 different SDA, without connection to the documented relationships between individuals.

Low Back Pain Induced by Posterior Longitudinal Ligament Incision in Percutaneous Transforaminal Endoscopic Lumbar Discectomy.

ObjectiveTo illustrate the posterior longitudinal ligament is one of the tissue candidates who can contribute to low back pain (LBP).MethodsThis is a retrospective study. A series of 72 patients who underwent single‐level percutaneous endoscopic lumbar discectomy performed for lumbar disc herniation with LBP from June 2014 to June 2016 were examined. There are 42 males and 30 females. The ages of patients were 40 to 57 years, and the mean age was 49.8 years. The symptomatic disc level was at L4‐5 in 43 patients and L5S1 in 29 patients. Thirty‐two patients (19 patients in L4‐5 disc level, 13 patients in L5S1 disc level) had LBP (which was limited to the lower back and buttock area) before the operation. All of the operative approaches were performed under local anesthesia. A posterior body diagram (15 cm × 10 cm) was made for this study to record the pain distribution. The centered foci of low back pain were subjectively recorded before, during, and after the operation. The transforaminal endoscopic spine system technology was used in this study. Radiological examinations (X‐ray, computed tomography, and magnetic resonance imaging) were performed prior to and after surgery. The Visual Analogue Score (VAS) and Oswestry Disability Index (ODI) scores were taken before and after the surgery to observe the degree of pain. The VSA and ODI score before and after operation were expressed as mean ± SD, and compared by t‐test for statistical analysis.ResultsWhen inciting the posterior longitudinal ligament during the operation, all 72 patients had provoked low back pain. Forty‐three patients with symptomatic discs at L4‐5 had pain foci in the lower back and upper gluteal region under the L4 spinous process. Twenty‐nine patients with symptomatic discs at L5S1 had pain foci in the gluteal region under the S1 spinous process. The pain localizations of L4‐5 and L5S1 were different. After the surgery, the provoked low back pain disappeared, and had not returned in any of the patients at the 6‐month follow‐up. After the operation, one patient suffered from lower limb pain that he did not have before the operation, and the lower limb pain abated a few days later. Three patients had cerebrospinal fluid leakage and were treated with higher pressure applied on the incision and bed rest for 10 days. During the 6‐months follow‐up period, the mean VAS decreased from 5.97 ± 1.10 to 2.13 ± 0.78. The mean ODI score decreased from 23.14 ± 3.28 to 7.92 ± 1.85.ConclusionsThe intervertebral posterior longitudinal ligament may be one of the tissues from which low back pain originates.

4188 Consistent Differences in Lumbar Spine Alignment Between Low Back Pain Subgroups and Sexes during Clinical and Functional Sitting Tests

OBJECTIVES/GOALS: Test the validity of a system for subgrouping people with CLBP by comparing lumbar spine alignment in two CLBP subgroups and sexes during clinical tests of maximum flexed and extended sitting and a functional test of preferred sitting. METHODS/STUDY POPULATION: Using the Movement System Impairment classification system, 154 participants with CLBP were subgrouped based on the predominant direction of altered movement and alignment patterns and symptoms during a standardized examination. Participants performed a functional test of preferred sitting followed by clinical tests of maximum flexed and extended sitting in random order. Reflective markers were place superficial to T12, L3 and S1 spinous processes. 3D marker co-ordinate data were collected using an 8 camera motion capture system. Sagittal plane lumbar curvature angle (LCA), defined as the angular distance between T12, L3, and S1 landmarks was calculated for each test. A three-way mixed effect ANOVA model was used to examine the following effects: test, subgroup, sex, test*subgroup, test*sex, subgroup*sex. RESULTS/ANTICIPATED RESULTS: Test: Lumbar alignment patterns were different for flexed [LCA = 7.4° (6.1, 8.7)], extended [LCA = −22.6° (−23.9,−21.3)], and preferred [LCA = −3.8° (−5.2,−2.5)] sitting tests. LBP subgroup: Rotation-extension [LCA = −7.5° (−8.7,−6.3)] had more extended lumbar alignment than rotation [LCA = −5.2° (−6.2,−4.2)]. Sex: Women had more extended lumbar alignment [LCA = −10.3° (−11.2,−9.3)] than men [LCA = −2.5° (−3.7,−1.2)]. Test*sex: The difference in lumbar alignment between women and men was smaller during the flexed sitting test [women = 4.2° (2.5, 5.9), men = 9.9° (7.8, 12.1)], compared to extended [women = −27.5° (−29.2, −25.8), men = −17.0° (−9.2, −14.8)] and preferred [women = −7.4° (−9.1, −5.8), men = −0.3° (−2.5, 1.8)]. The test*subgroup (p = 0.84) and subgroup*sex (p = 0.87) interactions were not significant.

Cauda Equina Conduction Time Determined by F-Waves in Normal Subjects and Patients With Neurogenic Intermittent Claudication Caused by Lumbar Spinal Stenosis.

Lumbar spinal stenosis typically presents with neurogenic intermittent claudication. The aim of this study was to investigate cauda equina conduction time (CECT) in patients with neurogenic intermittent claudication caused by lumbar spinal stenosis and its relationship with age and body height in normal subjects. The study included 172 normal subjects (group C) (mean age 44.1 ± 16.6 years; mean height 163.7 ± 8.9 cm). Forty-seven patients (group L) (mean age 71.3 ± 8.7 years; mean height 158.8 ± 11.2 cm) underwent surgery because of neurogenic intermittent claudication in cauda equina type of lumbar spinal stenosis. Motor-evoked potentials from the abductor hallucis were recorded. Magnetic stimulation was delivered at the S1 spinous process. Compound muscle action potentials (CMAPs) and F-waves were also recorded after supramaximal electric stimulation of tibial nerves. The peripheral motor conduction time (PMCT) was calculated from the latencies of CMAPs and F-waves as follows: (CMAPs + F-waves - 1)/2. The CECT was calculated by subtracting the onset latency of the motor-evoked potentials from PMCT. The mean values for F-wave latencies, motor-evoked potential latencies, and CECT were 44.5 ± 3.3, 20.6 ± 1.8, and 3.4 ± 0.8 milliseconds, respectively. F-wave and motor-evoked potential latencies showed significant positive linear correlations with age and body height. However, no significant correlation was found between CECT and age (P = 0.43) or body height (P = 0.26). Mean CECT was 5.7 ± 1.5 in group L. There was a significant difference between groups C and L (P < 0.05). The CECT value of normal subjects was 3.4 ± 0.8 milliseconds regardless of age and body height. We suggest that CECT may be a useful factor to consider when evaluating patients with neurogenic intermittent claudication.

Application of the Coflex Interlaminar Stabilization in Patients With L5/S1 Degenerative Diseases: Minimum 4-Year Follow-up

The Coflex is one of the representatives of posterior dynamic interspinous process device, but no study with the application of Coflex interlaminar stabilization in L5/S1 level has been performed. The aim of this study was to evaluate the feasibility and validity of the Coflex interlaminar stabilization in the treatment of degenerative lumbar diseases on L5/S1 level. A retrospective study was conducted for a consecutive series of 33 patients with degenerative lumbar spinal stenosis or lumbar disc herniation located in L5/S1 between November 2007 and September 2010. Subjects were all received decompressive laminectomy with implantation of Coflex device. Clinical effects were evaluated by visual analog scale and Oswestry Disability Index. Radiographs were done preoperatively, postoperatively, and at final follow-up. The Coflex devices were successfully implanted in all subjects. Fourteen cases completed the operations by inverting the prosthesis on account of too short S1 spinous processes. During the minimum 4-year follow-up period, all patients had obvious improvement in clinical effects (P < 0.05). Radiological evaluation revealed that dorsal intervertebral space height and intervertebral foramen height of target level increased significantly in all cases postoperatively and maintained well to final follow-up. In addition, the sagittal range of motion of operated level was restricted (P < 0.05), and the range of motion of adjacent segment did not change much (P > 0.05). The Coflex is an efficacious dynamic interspinous process device for the treatment of degenerative lumbar diseases that can apply to L5/S1.

Dynamic global sagittal alignment evaluated by three-dimensional gait analysis in patients with degenerative lumbar kyphoscoliosis.

Sagittal vertical axis (SVA) is the most commonly used parameter for evaluating global sagittal alignment (GSA) in a static condition. However, its dynamic statuses remain unclear. The aim of this study was to evaluate dynamic GSA of degenerative lumbar kyphoscoliosis (DLKS) using three-dimensional motion analysis system (3D-MAS). Twenty-six patients with DLKS underwent gait analysis using 3D-MAS. Static (S-) and dynamic (D-) trunk angle (TA) (the angle between the vertical axis and the line connecting C7 and S1 spinous processes) and S-sagittal trunk shift (STS) and D-STS (the distance between the two vertical lines running through C7 and S1 spinous process) were recorded during treadmill walking. Pelvic angle (PA) (the angle between the horizontal axis and the line connecting the posterior and anterior superior iliac spine) were also recorded. S-PA and D-PA represent retroversion or anteversion of the pelvis, which can be substituted for pelvic tilt. As to dynamic parameters, those at the initial five steps (Di) and the final five steps (Df) of treadmill walking were also recorded. The median S-TA, S-STS, and S-PA were 16.0°, 11.9cm, and -5.5° (retroversion). The median D parameters were Di-TA/Df-TA 21.8°/26.9°; Di-STS/Df-STS 14.1/21.1cm; and Di-PA/Df-PA 15.7°/22.8° (anteversion). All D parameters were significantly greater than S parameters (P<0.01) and all Df parameters were also significantly worse than Di parameters (P<0.001). Thus, compensated GSA by pelvic retroversion in static condition was lost due to anteversion change of the pelvis immediately after start of walking and worsened over time. Dynamic GSA assessment using 3D-MAS can avoid underestimation of GSA loss that is detected by static standing full-length radiography.

Sacral spinous processes: a morphologic classification and biomechanical characterization of strength

BackgroundThere has been increasing interest in using the lumbosacral spinous processes for fixation as a less invasive alternative to transpedicular instrumentation. Alhough prior studies have described the appearance and biomechanics of lumbar spinous processes, few have evaluated the dimensions, morphology, or strength of the sacral spinous processes. PurposeThe goals of this study were to characterize the morphology of the S1 spinous process and biomechanical strength of the S1 spinous process when loaded in a cranial direction. Study DesignThis study was performed as both an analysis of radiographic data and biomechanical testing of cadaveric specimens. MethodsLumbosacral spine radiographs and computed tomography scans of 20 patients were evaluated for visibility and morphology of the S1 spinous process. S1 spinous process length, height, and size of the L5–S1 segment were measured. Additionally, 13 cadaveric lumbosacral spinal segments were obtained for biomechanical testing and morphologic analysis. Specimens were loaded at the S1 spinous process in a cranial direction via a strap, simulating resistance to a flexion moment applied across the L5–S1 segment. Peak load to failure, displacement, and mode of failure were recorded. ResultsThe S1 spinous process was clearly visible on lateral radiographs in only 10% of patients. Mean spinous process length (anterior-posterior) was 11.6 mm while mean spinous process height (cranial-caudal) was 23.1 mm. We identified six different morphologic subtypes of the S1 spinous process: fin, lumbar type, fenestrated, fused, tubercle, and spina bifida occulta. During tension loading of the S1 spinous process in the cephalad direction, mean peak load to failure was 439N, with 92% of specimens failing by fracture through the spinous process. ConclusionsThis is the first study evaluating sacral spinous process morphology, visibility, and biomechanical strength for potential instrumentation. Compared with lumbar spinous processes, sacral spinous processes are smaller with more variable morphology but have similar peak load to failure. For ideal visualization of morphology and suitability for interspinous fixation,preoperative three-dimensional imaging may be a valuable tool over plain radiographs.

Dynamic sagittal balance evaluated by 3-dimentional gait analysis in patients with degenerative lumbar kyphosis

Method Twenty-six patients with DLKS underwent gait analysis using 3-dimentional motion analysis system (3D-MAS). Two reflection markers were attached to the skin surface on C7 and S1 spinous processes in all patients. Then they walked on treadmill at self-selected walking speed, and 3-dementional location of these surface makers (C7.S1) were recorded by synchronized 4 cameras that were placed separately. The angles between vertical axis and the line C7-S1 (dynamic-trunk angle: D-TA) and horizontally projected distance of the line C7-S1 (dynamic sagittal vertical axis; D-SVA) were continuously recorded during walking. D-TA and D-SVA were compared to static trunk angle (S-TA) and static SVA(S-SVA) that were obtained regular standing fulllength lateral X-ray.

Assessment of Three-Dimensional Lumbar Spine Vertebral Motion During Gait with Use of Indwelling Bone Pins

This study quantifies the three-dimensional motion of lumbar vertebrae during gait via direct in vivo measurement with the use of indwelling bone pins with retroreflective markers and motion capture. Two previous studies in which bone pins were used were limited to instrumentation of two vertebrae, and neither evaluated motions during gait. While several imaging-based studies of spinal motion have been reported, the restrictions in measurement volume that are inherent to imaging modalities are not conducive to gait applications. Eight healthy volunteers with a mean age of 25.1 years were screened to rule out pathology. Then, after local anesthesia was administered, two 1.6-mm Kirschner wires were inserted into the L1, L2, L3, L4, L5, and S1 spinous processes. The wires were clamped together, and reflective marker triads were attached to the end of each wire couple. Subjects underwent spinal computed tomography to anatomically register each vertebra to the attached triad. Subjects then walked several times in a calibrated measurement field at a self-selected speed while motion data were collected. Less than 4° of lumbar intersegmental motion was found in all planes. Motions were highly consistent between subjects, resulting in small group standard deviations. The largest motions were in the coronal plane, and the middle lumbar segments exhibited greater motions than the segments cephalad and caudad to them. Intersegmental lumbar flexion and axial rotation motions were both extremely small at all levels. The lumbar spine chiefly acts to contribute abduction during stance and adduction during swing to balance the relative motions between the trunk and pelvis. The lumbar spine acts in concert with the thoracic spine. While the lumbar spine chiefly contributes coronal plane motion, the thoracic spine contributes the majority of the transverse plane motion. Both contribute flexion motion in an offset phase pattern. This is a valid model for measuring the three-dimensional motion of the spine. Normative data were obtained to better understand the effects of spine disorders on vertebral motion over the gait cycle.

Interspinous Dynamic Stabilization Using Diam Device at L5-S1 Level

Introduction Interspinous stabilization has limited indications especially at L5-S1 level. But there's no description of level anatomy of L5-S1 hopeful for DIAM (Medtronic, Memphis, TN, USA) insertion in the literature. Materials and Methods We have suggested that short number of CT parameters could be used to check if level anatomy satisfied the requirements of good interspinous stabilization. The parameters are as follows: sagittal size of the spinous process “working part” (from yellow ligament to curved part)&gt;13 mm, it's width from 4 to7 mm, sagittal translation of the vertebra ≤4 mm, segmental angle from 5 to 20°, interspinous height ≤14 mm, density of spinous process (Hounsfield) &gt;200 units, height of the disk&gt;50% (compared to the upper one), S1 spinous process slope (angle among S1 endplate line and upper edge of it's spinous process)&lt;35°. We performed retrospective study among patients operated on L5-S1 level with DIAM device according to offered parameters (Group A - 52 patients 24 men, 28 women, mean age 39,4 ± 9,1) and group of patients, treated with decompressive operation at L5-S1 alone (Group B - 52 patients 19 men, 33 women, mean age 42.7 ± 10.1). Indication for surgery were: disсal herniations, segmental hypermobility, and lateral recess stenosis. Symptoms of leg and back pain and fail of the conservative treatment for 4 weeks were also necessary. Decompressive operations were: microdiscectomy, laminotomy, and medial facet resection. We have compared close (10 days after surgery) and remote results (24 month after surgery) by visual analog scale of pain, Oswestry disability index, patients satisfaction rate, operation time, and blood loss. Results In Group A, no reoperations, no unsatisfactory results, 3 satisfactory results, 49 good and excellent results, no implant failure. In Group B, 2 reoperations (unsatisfactory results), 7 satisfactory results, 43 good and excellent results. Visual analog scale for back pain; before the surgery: Group A-52.13 ± 23.5; Group B-48.09 ± 22.49 (no difference: p = 0.39); 10 days after surgery: Group A-19.8 ± 8.74, Group B-16.2 ± 8.44(difference at p = 0.02); 24 month after surgery: Group A-13.31 ± 10.73, Group B-20.17 ± 12.52 (difference at p = 0.00043). Oswestry index; before the operation: Group A 46.26 ± 15.62, Group B-51.27 ± 22.54 ( p = 0.27); 24 month after surgery: Group Я-10.26 ± 7.28, Group B-15.02 ± 10.9 ( p = 0.032). Blood loss at Group Я-110.7 ± 35.2 mL, Group B-67.4 ± 15.5 Мл( p = 0.0018). Operative time; Group A-115.5 ± 39.6 minutes, Group B-84.6 ± 26.7 minutes ( p &lt; 0.001). Conclusion Interspinous dynamic stabilization using DIAM device is useful at L5-S1 level in cases where level anatomy lets you to set the device. CT is a method of choice for preoperative planning of the interspinous stabilization. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared

Evaluating the Relationship Among Cavitation, Zygapophyseal Joint Gapping, and Spinal Manipulation: An Exploratory Case Series

Objective This project determined the feasibility of conducting larger studies assessing the relationship between cavitation and zygapophyseal (Z) joint gapping following spinal manipulative therapy (SMT). Methods Five healthy volunteers (average age, 25.4 years) were screened and examined against inclusion and exclusion criteria. High-signal magnetic resonance imaging (MRI) markers were fixed to T12, L3, and S1 spinous processes. Scout images were taken to verify the location of the markers. Axial images of the L4/L5 and L5/S1 levels were obtained in the neutral supine position. Following the first MRI, accelerometers were placed over the same spinous processes; and recordings were made from them during side-posture positioning and SMT. The accelerometers were removed, and each subject was scanned in side-posture. The greatest central anterior to posterior Z joint spaces (gap) were measured from the first and second MRI scans. Values obtained from the first scan were subtracted from those of the second, with a positive result indicating an increase in gapping following SMT (positive gapping difference). Gapping difference was compared between the up-side (SMT) joints vs the down-side (non-SMT) joints and between up-side cavitation vs up-side noncavitation joints. Results Greater gapping was found in Z joints that received SMT (0.5 ± 0.6 mm) vs non-SMT joints (−0.2 ± 0.6 mm), and vertebral segments that cavitated gapped more than those that did not cavitate (0.8 ± 0.7 vs 0.4 ± 0.5 mm). Conclusions A future clinical study is quite feasible. Forty subjects (30 in an SMT group and 10 in a control group) would be needed for appropriate power (0.90).

Assessing joint vibration during spinal manipulation

This IRB‐approved study assessed the relationship between cavitation and zygapophysial (Z) joint gapping following spinal manipulation (adjusting) in 5 healthy volunteers. High signal MRI markers were used to accurately identify the T12, L3, and S1 spinous processes during scout views. Axial images of the L4/L5 and L5/S1 levels were obtained in the neutral supine position. Each subject was then positioned on the side, and accelerometers were placed over the marked spinous processes. Recording from the accelerometers was done from final positioning through adjusting. The subject was then scanned in side posture position (accelerometers removed). Using a digitizer, the greatest A‐P central Z joint articular surface distances were measured on the 1st and 2nd scans; the difference between the 2 measurement values was the gapping difference, GD; a positive value indicating an increase in gapping following the spinal adjustment. GD was compared between up‐side (adjusted), down‐side (non‐adjusted), cavitation, and non‐cavitation joints.ResultsGD was increased in Z joints that were adjusted [0.5 (SE 0.2) mm] vs. non‐adjusted [−0.2 (SE 0.2) mm], and vertebral segments with cavitation gapped more than no cavitation [0.8 (SE 0.4) vs. 0.4 (SE 0.2) mm].ConclusionsA future clinical study is quite feasible. Forty subjects would be needed for appropriate power (0.80). Funding: NIH/NCCAM (#2R01AT000123).

A Hard Fall: An Isolated Fracture of Lumbarized S1 Spinous Process

A case of an isolated lumbarized S1 spinous process fracture due to direct trauma from a fall on the lower back is reported here. The patient was treated nonoperatively. Pain subsided and he returned to every day. To alert physicians of this rare fracture as part of the differential diagnosis in cases of direct trauma to the lower spine. The method of diagnosing such pathology and its treatment are described. A 22-year-old man was admitted with lower back pain after falling down a flight of stairs during which, he sustained a direct blow to his lower back. The patient had a scrape over L5-S1 area and midline tenderness around the L5-S1 area. He was neurologically intact. Radiographs revealed a lumbarized S1 vertebra and an isolated fracture of the spinous process of S1. The fracture resulted from the direct trauma to the S1 lumbarized vertebrae. The direct trauma and the fact that the patient has a lumbarized S1 vertebra with a thin spinous process contributed to the fragility of the spinous process. Nonoperative measures, physical therapy, primarily analgesics, and local heat, were employed. The patient returned to his normal routine after 3 weeks. Few cases of isolated spinous process fractures have been described, and, to our knowledge, this is the first reported case of an isolated fracture of a lumbarized S1 spinous process to due to direct trauma. Radiograph imaging was adequate to determine the extent of the injury. Nonoperative treatment can allow the patient to return to every day life without the need of surgery.

Evaluation of segmental postural characteristics during quiet standing in control and Idiopathic Scoliosis patients

Background. The complex skeletal deformations that accompany Idioapthic Scoliosis pose a challenge to the clinician to non-invasively discriminate Idiopathic Scoliosis patients from children with no pathology. Therefore, the focus of this study is to non-invasively evaluate the position and amplitude of displacement of the pelvis, shoulders and thorax during quiet standing of Idiopathic Scoliosis patients and control subjects. Methods. The quiet standing posture of 18 healthy adolescent females and 22 Idiopathic Scoliosis subjects was evaluated using an Optotrak 3020 position sensor over a period of 120 s, with 4 repeat trials. Outcome measures included the mean position, root mean square amplitude and range over the duration of 120 s trials for both linear and angular measures of the pelvis, thorax and shoulders. Appropriate sample times were chosen and evaluated for stability over the 120 s period, and between trial reliability was evaluated. Findings. There was a significant difference between groups for the mean position of the shoulder blade rotation in reference to the base of support and to the pelvis. The Idiopathic Scoliosis patients had a significantly larger root mean square amplitude of anterior–posterior displacement of the T1 and S1 spinous processes in reference to the base of support. There was no difference between the sample durations to estimate the mean position of the body segments, however the root mean square increased significantly. Interpretation. This study demonstrates that postural abnormalities are evident during quiet standing in Idiopathic Scoliosis patients.

Chiropractic biophysics digitized radiographic mensuration analysis of the anteroposterior lumbopelvic view: A reliability study

Objective: To investigate the reliability of a radiographic measurement procedure that uses a computer and sonic digitizer to determine projected spinal displacements from an ideal normal position. Design: A blind, repeated-measure design was used. Anteroposterior lumbopelvic radiographs were presented to each of 3 examiners in random order. Each film was digitized, and the films were randomized for a second run. Setting: Private, primary-care chiropractic clinic. Main Outcome Measures: The angle of the sacral base in comparison to a true horizontal line (horizontal base angle), lumbodorsal angle, lumbosacral angle, and the thoracic translational displacement from true vertical determined as the perpendicular distance from the center of T12 to a vertical axis line drawn from the center of the S1 spinous process cephalad and parallel to the lateral edge of the x-ray film. Results: Intraexaminer reliability for the (a) horizontal base angle was .72 to .94, with confidence intervals included in the range of .52 to .97; (b) lumbodorsal angle was .90 to .96, with confidence intervals in the range of .82 to .98; (c) lumbosacral angle was .84 to .96, with confidence intervals in the range of .72 to .98, and (d) thoracic translational displacement from vertical was .95 to .97, with confidence intervals included in the range of .91 to .99. Interexaminer reliability for the three examiners ranged from .71 to .97. Conclusions: Measures similar to those described in this study are commonly used to measure and categorize spinal displacements from true vertical alignment (ie, scoliosis measurements). Most patient assessment methods used in chiropractic have poor or unknown reliability. The one possible exception to this rule is spinal displacement analysis performed on radiographs. In chiropractic, intraclass correlation coefficients values greater than .70 are considered accurate enough for use in clinical and research applications. The measures tested here would fit within these guidelines of reliability. Establishing reliability is an important first step in evaluating these measures so that future studies of validity may be undertaken. (J Manipulative Physiol Ther 1999;22:309–15)