L5 Lumbar Research Articles

Ultrasound guided spinal catheter insertion in piglet: preliminary results

ObjectiveTo describe the ultrasound (US) evaluation of the cervical, thoracic and lumbar spinal tracts in piglets and to evaluate the feasibility of the ultrasound guided spinal catheter placement in newborn and paediatric piglets. Study designProspective experimental study. AnimalsA total of two piglet cadavers (age, 7 and 14 days) and eight commercial crossbreed piglets divided into four groups according to age: 7 (P7), 14 (P14), 21 (P21) and 28 (P28) days. MethodsIn the first part of the study an ultrasound examination of the spinal tract was performed in piglet cadavers applying the transverse and the longitudinal approaches in sternal and lateral recumbencies. In the second phase, the piglets were anaesthetized with sevoflurane. A US examination with a 10 MHz linear probe was performed and a spinal catheter was introduced between the spinous processes of L2 and L3 lumbar vertebrae using an in-plane technique and its advancement was monitored with the probe. At the end of procedure, the catheter was removed. The piglets recovered from anaesthesia and were monitored for one week. ResultsIn phase I the authors identified the paramedian longitudinal approach as the most feasible for spinal structure evaluation in piglets. In phase II, the paramedian longitudinal views enabled a good visualization of the spinal cord and of the catheter advancement up to the cisterna magna in groups P7 and P14. In groups P21 and P28 it was not possible to visualize the neuroaxial structures and the spinal catheter using the same approach. No clinical alterations were recorded during the procedure or the following days. Conclusions and clinical relevanceUS-guided spinal catheter placement appeared a feasible technique in piglets younger than 14 days but it is not useful in older piglets.

The radiological distance between the lumbar pedicle and laminar edges.

Lumbar foraminal inner zone herniations are challenging cases, for which there are variety of approaches. However, there is no information about the distance between these herniations and the edges of the respective lamina. The aim of this study was to measure the distance between the inferomedial aspect of lumbar pedicles and laminar edges. The lumbar CT images of 30 cases were reviewed. The distances between the edges of the lamina and the inferomedial aspects of the respective pedicles were measured. The study was performed on L3, L4, and L5 lumbar vertebrae on both sides. The mean distance between the upper edge of the lamina and the inferomedial aspect of the respective pedicle was found to be 10.8±3.5, 11.6±2.4, and 14.1±2.3mm on the left side, and 11.1±4.4, 12.0±2.5, and 13.8±3.2mm on the right side of L3, L4, and L5 vertebrae. The mean distance between the inferior edge of the lamina and the inferomedial aspect of the respective pedicle was found to be 23.8±4.2, 19.3±3.5, and 11.6±2.9mm, on the left side, and 23.9±3.2, 19.1±3.7, and 12.4±2.8mm on the right side of L3, L4, and L5 vertebrae. There was no statistically significant difference between values of the left and right sides (p>0.05). This study revealed that distance between the inferomedial aspect of lumbar pedicles and the superior edge of the same lamina was shorter than the distance between the inferomedial aspect of lumbar pedicles and the inferior edge of the same lamina at L3 and L4 level. It was concluded that this shorter distance could be taken into consideration during surgery on inner zone 1 foraminal herniations.

Differences in body composition between patients with early or metastatic breast cancer (BC).

e21707 Background: There is growing evidence in oncology that skeletal muscle (SM) loss, known as sarcopenia, can be identified from routine computed tomography (CT) imaging and used to predict increased chemotherapy toxicity, mortality, and other adverse clinical outcomes (Shachar-EJC, 2016, Shachar-CCR, 2016). The contributions of age-related and cancer-related loses in SM at diagnosis remains poorly understood. This study compares CT-derived measures of SM at the time of diagnosis in patients with early BC (EBC) versus metastatic BC (MBC) patients to investigate the impact of metastatic cancer on SM. Methods: Body composition measures were compared between patients with EBC receiving adjuvant chemotherapy and MBC initiating first line palliative chemotherapy. Measures were derived from analysis CT scans of L3 lumbar segments using radiological software (ABACS). Measures include: skeletal muscle area (SMA), density (SMD), index (SMI = SMA/height ^2), and integrated density (SMID = SMI x SMD). Sarcopenia was defined as SMI < 41(Martin-JCO, 2013). Lean body mass (LBM) was calculated (kg) = [(L3 Muscle measured by CT (cm2) × 0.3) + 6.06]) (Prado-CCR, 2009). Body surface area (BSA) was calculated using the Mosteller formula. T-tests (continuous) and Chi-squared tests (categorical) compared variables between groups; multivariable linear regression models controlled for age and body mass index (BMI). Results: MBC patients (n = 40) were older than EBC (n = 151) (56 vs 49 years, p < 0.001). Mean BMI and BSA were similar in both groups (29.0 vs 28.8, p = 0.84; 1.87 vs 1.86 m2, p = 0.55). After adjusting for age and BMI, SMI (41.3 vs 44.7 cm2/m2, p = 0.009), SMD (29.8 vs 36.4 Hounsfield Units, p < 0.0001), SMG (1250 vs 1612, p < 0.0001), and LBM (39.3 vs 41.9 kg, p = 0.024) were significantly lower in the MBC group. The MBC group included significantly more sarcopenic patients (58% vs 31%, p = 0.0016). Conclusions: Although BMI and BSA were similar in EBC and MBC patients, SM measures showed significant differences. MBCs had lower LBM, SMI, and SMD. More advanced BC was associated with higher proportions of sarcopenia. Further research is needed to explore interventions in sarcopenic patients in order improve outcomes in women with both EBC and MBC.

Reduced bone mass and preserved marrow adipose tissue in patients with inflammatory bowel diseases in long-term remission.

Reduced bone mass is known to occur at varying prevalence in patients with inflammatory bowel diseases (IBD) because of inflammation, malnutrition, and steroid therapy. Osteoporosis may develop in these patients as the result of an imbalanced relationship between osteoblasts and adipocytes in bone marrow. This study aimed to evaluate for the first time bone mass and bone marrow adipose tissue (BMAT) in a particular subgroup of IBD patients characterized by long-term, steroid-free remission. Patients with Crohn's disease (CD; N=21) and ulcerative colitis (UC; N=15) and controls (C; N=65) underwent dual X-ray energy absorptiometry and nuclear magnetic resonance spectroscopy of the L3 lumbar vertebra for BMAT assessment. Both the CD and UC subgroups showed significantly higher proportions of patients than controls with Z-score ≤-2.0 at L1-L4 (C 1.54%; CD 19.05%; UC 20%; p=0.02), but not at other sites. The proportions of CD patients with a T-score ˂-1.0 at the femoral neck (C 18.46%; CD 47.62%; p=0.02) and total hip (C 16.92%; CD 42.86%; p=0.03) were significantly higher than among controls. There were no statistically significant differences between IBD patients and controls regarding BMAT at L3 (C 28.62±8.15%; CD 29.81±6.90%; UC 27.35±9.80%; p=0.67). IBD patients in long-term, steroid-free remission may have a low bone mass in spite of preserved BMAT. These findings confirm the heterogeneity of bone disorders in IBD and may indicate that factors involved in bone loss in active disease may have long-lasting effects on these patients.

Skeletal muscle measures and physical function in older adults with cancer: sarcopenia or myopenia?

BackgroundSkeletal muscle loss, commonly known as sarcopenia, is highly prevalent in older adults and linked with adverse outcomes in cancer, yet the definition and role of sarcopenia remains uncertain. The aim of this study was to examine the association of Computerized Tomography (CT) assessed skeletal muscle measures with physical function in older adults with cancer.ResultsCTs for 185 patients were available. Median age 73 (IQR 68–76) and 56.5% female. After controlling for sex and BMI, we found no evidence that SMI was associated with physical function impairments. Both SMD and SMG were associated physical function impairments and higher values were associated with decreased limitations in instrumental activities of daily living (RR 0.84 [CI 0.73–0.96] and 0.94 [CI 0.89–0.99], respectively), climbing stairs (RR 0.84 [CI 0.76–0.94] and 0.91 [CI 0.87–0.96]), walking 1 block (RR 0.77 [CI 0.67–0.90] and 0.91 [CI 0.85–0.97]), and prolonged Timed Up and Go (RR 0.83 [CI 0.75–0.92] and 0.92 [CI 0.88–0.96]).Materials and MethodsUsing the Carolina Senior Registry, we identified patients with CT imaging performed within 60 days +/− of baseline geriatric assessment (GA). Skeletal muscle area and density (SMD) were analyzed from L3 lumbar segments. Muscle area and height (m2) were used to calculate skeletal muscle index (SMI). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD.ConclusionsSkeletal muscle mass as assessed from CT imaging was not associated with physical function impairments. Skeletal muscle radiodensity was more associated with physical function and may aid in identifying older adults at risk for functional impairments.

A novel diagnostic parameter, foraminal stenotic ratio using three-dimensional magnetic resonance imaging, as a discriminator for surgery in symptomatic lumbar foraminal stenosis

Background ContextNo previous studies have reported the radiological features of patients requiring surgery in symptomatic lumbar foraminal stenosis (LFS). PurposeThis study aims to investigate the diagnostic accuracy of a novel technique, foraminal stenotic ratio (FSR), using three-dimensional magnetic resonance imaging for LFS at L5–S by comparing patients requiring surgery, patients with successful conservative treatment, and asymptomatic patients. Study DesignThis is a retrospective radiological comparative study. Patient SampleWe assessed the magnetic resonance imaging (MRI) results of 84 patients (168 L5–S foramina) aged ≥40 years without L4–L5 lumbar spinal stenosis. The foramina were divided into three groups following standardized treatment: stenosis requiring surgery (20 foramina), stenosis with successful conservative treatment (26 foramina), and asymptomatic stenotic foramen (122 foramina). Outcome MeasuresForaminal stenotic ratio was defined as the ratio of the length of the stenosis to the length of the foramen on the reconstructed oblique coronal image, referring to perineural fat obliterations in whole oblique sagittal images. We also evaluated the foraminal nerve angle and the minimum nerve diameter on reconstructed images, and the Lee classification on conventional T1 images. Materials and MethodsThe differences in each MRI parameter between the groups were investigated. To predict which patients require surgery, receiver operating characteristic (ROC) curves were plotted after calculating the area under the ROC curve. ResultsThe FSR showed a stepwise increase when comparing asymptomatic, conservative, and surgical groups (mean, 8.6%, 38.5%, 54.9%, respectively). Only FSR was significantly different between the surgical and conservative groups (p=.002), whereas all parameters were significantly different comparing the symptomatic and asymptomatic groups. The ROC curve showed that the area under the curve for FSR was 0.742, and the optimal cutoff value for FSR for predicting a surgical requirement in symptomatic patients was 50% (sensitivity, 75%; specificity, 80.7%). ConclusionsThe FSR determined LFS requiring surgery among symptomatic patients, with moderate accuracy. Foramina occupied ≥50% by fat obliteration were likely to fail conservative treatment, with a positive predictive value of 75%.

Intraoperative Radiographic Determination of Ureteral Length as a Method of Determining Ideal Stent Length.

Accurate determination of ureteral length (UL) and appropriate stent length remains a challenge. The objective of this study was to describe an intraoperative technique to measure UL and determine appropriate stent length, and to compare this technique with other methods of determining appropriate stent length. Patients undergoing ureteroscopy requiring postoperative stenting and who had a preoperative CT were prospectively identified. Gender, age, height, body mass index, L1 to L5 lumbar height on CT, and surgeon's estimate of UL were recorded. UL was measured using four methods: direct measurement with a ureteral catheter, ureteropelvic junction (UPJ) to ureterovesical junction distance on axial and coronal CT, and using a novel intraoperative radiographic technique. Radiographic measurement was performed using a radiographic nipple marker affixed to the skin over the ureteral orifice (UO) and an angiographic catheter with radiopaque markings at 1 cm intervals. UL was the distance from the UPJ to the marker at the UO measured using the catheter markers. Correlation between direct measurement and the recorded variables and methods of ureteral measurement were calculated. Stent length was chosen based on radiographic measurement. Stents were deemed of appropriate length if they showed a proximal coil in the renal pelvis and a distal coil in the bladder without crossing midline. Twenty-five ureters from 23 patients were included. Radiographically measured UL was strongly correlated with direct measurement. (r = 0.873, p < 0.01). Coronal and axial CT ULs were significantly associated with direct measurement (p < 0.05). Height, lumbar height, and surgeon's estimate of UL were not. Stents were deemed of appropriate length in 23/25 cases (92%). This new method for radiographic UL measurement is strongly correlated with directly measured UL. A length of stent chosen based on radiographic UL resulted in an appropriate stent length.

The impact of sarcopenia on toxicity and pharmacokinetics of 5-fluorouracil (5FU) in colorectal cancer.

633 Background: Great heterogeneity exists in the ability of adults with cancer to tolerate treatment. Variability in body composition may affect rates of metabolism of cytotoxic agents and contribute to the variable chemotherapy toxicity observed. The goal of this study was to explore the impact of body composition, in particular sarcopenia, on the pharmacokinetics of 5-fluorouracil (5FU) in a cohort of patients receiving FOLFOX +/- bevacizumab for colorectal cancer. Methods: We performed a secondary analysis of a completed multicenter trial that investigated pharmacokinetic-guided 5FU in patients receiving mFOLFOX6 +/- bevacizumab [Patel et al. The Oncologist 2014]. Computed Tomography (CT) images that were performed as part of routine care were used to for body composition analysis. Skeletal muscle area (SMA) and density (SMD) were analyzed from CT scan L3 lumbar segments using radiological software. SMA and height (m2) were used to calculate skeletal muscle index (SMI = SMA/m2). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD. Differences were compared using two group t-tests and fisher’s exact tests. Results: Of the 70 patients from the original study, 25 had available CT imaging. The mean age was 59, 52% female, 80% Caucasian, and 92% with either stage III or IV disease. Eleven patients (44%) had grade 3/4 toxicity, and 12 patients were identified as sarcopenic (48%) [per Martin et al. JCO 2013]. Sarcopenic patients had numerically higher first cycle 5FU AUCs compared to non-sarcopenic patients (19.3 vs. 17.3 AUC, p= 0.43) and higher grade 3/4 toxicities (50 vs 38.5%, p= 0.70). Patients with low SMG ( &lt; 1475 AU) had higher grade 3/4 toxicities (62 vs 25%, p= 0.11) and higher hematologic toxicities (46 v 8%, p= 0.07). Conclusions: CRC patients with sarcopenia had numerically higher first cycle AUCs of 5FU and a higher incidence of severe toxicities; however, this was not statistically significant, possibly due to limited sample size. SMG, an integrated muscle measure, was more highly correlated with toxicity outcomes than either SMI or SMD alone. Further research exploring the role of body composition in pharmacokinetics is needed with a focus on alternative dosing strategies in sarcopenic patients.

Lumbar spinal muscles and spinal canal study by MRI three-dimensional reconstruction in adult lumbar spinal stenosis

BackgroundLumbar spinal stenosis is degenerative disc disease most common manifestation. If stenosis degree seems poorly related to symptom severity, lumbar muscles role is recognized. Many studies report imaging methods, to analyze muscle volumes and fat infiltration (FI), but remain limited due to the difficulty to represent entire muscle volume variability. Recently a 3D muscle reconstruction protocol (using the deformation of a parametric specific object method (DPSO) and three-point Dixon images) was reported. It offers the ability to evaluate, muscles volumes and muscle FI. PurposeTo describe, in a lumbar spinal stenosis population, muscle volumes, muscle FI and lumbar spinal canal volume with 3D MRI images reconstructions. Materials and methodsTen adults presenting L4–L5 lumbar stenosis, were included. After specific MRI protocol, three-dimensional, muscle and spinal canal, reconstructions were performed. Muscle (psoas and paraspinal muscles) volumes and fat infiltration (FI), the spinal canal volume, age, and height were correlated one to each other with Spearman correlation factor. An ANOVA was performed to evaluate the intervertebral level influence (P≤0.05). ResultsMuscle volumes correlated with height (r=0.68 for psoas). Muscles FI correlated with age (r=0.66 for psoas) and lumbar spinal canal volume (r=0.91). Psoas and paraspinal volumes were maximum at L3–L4 level whereas FI increased from L1–L2 to L5–S1 level. DiscussionThese first results illustrate the importance to consider muscles entirely and report correlations between muscles FI, lumbar spinal canal volume and age; and between muscle volumes and patients height. Muscle degeneration seems more related to muscle FI than muscle volume. Level of evidence3.

Prevalence of osteoporosis in patients with chronic kidney disease (stages 3-5) in comparison with age- and sex-matched controls: A study from Kashmir Valley Tertiary Care Center.

Chronic kidney disease (CKD) is associated with a range of metabolic bone diseases. Fracture rates are higher in CKD patients than age-matched controls throughout all the five stages of CKD. Dialysis patients have 4 times as many hip fractures as expected for their age. CKD forms an independent risk factor for osteoporosis, even in the absence of traditional risk factors. This study was carried out at the nephrology unit in a tertiary care center of Kashmir to know the prevalence of osteoporosis in CKD patients having glomerular filtration rate (GFR) <60 mL/min (stages 3-5). Among the 151 cases studied, the average estimated GFR was 16.78 ± 10.714 mL/min. There were 98 males (64.9%) and 53 females (35.1%). Their mean age was 51.01 ± 14.138 years. Osteoporosis based on femoral neck T-Score was seen in 31 patients (31.6%) while 43 patients (28.5%) had osteoporosis at L1, L2 lumbar vertebrae. The prevalence of osteoporosis based on femoral neck T-Score as well as osteopenia was highest in stage-5 CKD. In our study, the body mass index (BMI) had a positive correlation with osteoporosis; low BMI patients were at higher risk for osteoporosis (P = 0.014). In the Kashmir valley, the prevalence of osteoporosis was 31.8% in CKD patients against 22% in controls. Thus, CKD forms an important risk factor for osteoporosis even in the absence of traditional risk factors. We recommend early screening, detection, and management of osteoporosis to reduce the burden of morbidity and mortality in this subset of patients.

Development, validity and reliability of a new pressure air biofeedback device (PAB) for measuring isometric extension strength of the lumbar spine

This study describes the development of a new portable muscle testing device, using air pressure as a biofeedback and strength testing tool. For this purpose, a pressure air biofeedback device (PAB®) was developed to measure and record the isometric extension strength of the lumbar multifidus muscle in asymptomatic and low back pain (LBP) persons. A total of 42 subjects (age 47.58 years, ±18.58) participated in this study. The validity of PAB® was assessed by comparing a selected measure, air pressure force in millibar (mb), to a standard criterion; calibrated weights in kilograms (kg) during day-to-day tests. Furthermore, clinical trial-to-trial and day-to-day tests of maximum voluntary isometric contraction (MVIC) of L5 lumbar multifidus were done to compare air pressure force (mb) to electromyography (EMG) in microvolt (μV) and to measure the reliability of PAB®. A highly significant relationship were found between air pressure output (mb) and calibrated weights (kg). In addition, Pearson correlation calculations showed a significant relationship between PAB® force (mb) and EMG activity (μV) for all subjects (n = 42) examined, as well as for the asymptomatic group (n = 24). No relationship was detected for the LBP group (n = 18). In terms of lumbar extension strength, we found that asymptomatic subjects were significantly stronger than LBP subjects. The results of the PAB® test differentiated between LBP and asymptomatic subject’s lumbar isometric extension strength without any risk to the subjects and also indicate that the lumbar isometric extension test with the new PAB® device is reliable and valid.

Biomechanical analysis of combining head-down tilt traction with vibration for different grades of degeneration of the lumbar spine

In recent years, a combination of traction and vibration therapy is usually used to alleviate low back pain (LBP) in clinical settings. Combining head-down tilt (HDT) traction with vibration was demonstrated to be efficacious for LBP patients in our previous study. However, the biomechanics of the lumbar spine during this combined treatment is not well known and need quantitative analysis. In addition, LBP patients have different grades of degeneration of the lumbar spinal structure, which are often age related. Selecting a suitable rehabilitation therapy for different age groups of patients has been challenging. Therefore, a finite element (FE) model of the L1–L5 lumbar spine and a vibration dynamic model are developed in this study in order to investigate the biomechanical effects of the combination of HDT traction and vibration therapy on the age-related degeneration of the lumbar spine. The decrease of intradiscal pressure is more effective when vibration is combined with traction therapy. Moreover, the stresses on the discs are lower in the “traction+vibration” mode than the “traction-only” mode. The stress concentration at the posterior part of nucleus is mitigated after the vibration is combined. The disc deformations especially posterior disc radial retraction is improved in the “traction+vibration” mode. These beneficial effects of this therapy could help decompress the discs and spinal nerves and therefore relieve LBP. Simultaneously, patients with grade 1 degeneration (approximately 41–50 years old) are able to achieve better results compared with other age groups. This study could be used to provide a more effective LBP rehabilitation therapy.

Normalizing GDNF expression in the spinal cord alleviates cutaneous hyperalgesia but not ongoing pain in a rat model of bone cancer pain.

Bone cancer pain (BCP) is the most common complication in patients with bone cancer. Glial cell line-derived neurotrophic factor (GDNF) is believed to be involved in chronic pain conditions. In this article, the expression and roles of GDNF were studied in a rat model of BCP induced by tibia injection of Walker 256 rat mammary gland carcinoma cells. Significant mechanical and thermal hyperalgesia and ongoing pain were observed beginning as early as day 5 post injection. The expression level of GDNF protein examined on day 16 after tibia injection was decreased in the L3 dorsal root ganglion (DRG) and lumbar spinal cord, but not in other spinal levels or the anterior cingulate cortex. Phosphorylation of Ret, the receptor for GDNF family ligands, was also decreased. Furthermore, normalizing GDNF expression with lentiviral vector constructs in the spinal cord significantly reduced mechanical and thermal hyperalgesia, spinal glial activation, and pERK induction induced by tibia injection, but did not affect ongoing pain. Together these findings provide new evidence for the use of GDNF as a therapeutic treatment for bone cancer pain states.

Effects of combined treatment with ibandronate and pulsed electromagnetic field on ovariectomy-induced osteoporosis in rats.

Ibandronate (IBN) and pulsed electromagnetic field (PEMF) have each shown positive effects for treating osteoporosis, but no study has evaluated the relative effects of these treatments combined. This study investigated the effects of IBN + PEMF on bone turnover, mineral density, microarchitecture, and biomechanical properties in an ovariectomized (OVX) rat model of osteoporosis. Fifty 3-month-old rats were randomly apportioned to receive a sham-operation (n = 10), or ovariectomy (n = 40). The latter group was equally divided as the model (OVX control) or to receive IBN, PEMF, or IBN + PEMF. Beginning the day after surgery, the IBN and IBN + PEMF groups received weekly subcutaneous IBN; the PEMF and IBN + PEMF groups were given daily PEMF during the same 12 weeks. After 12 weeks of treatments, biochemical parameters, bone mineral density (BMD), microarchitecture parameters, biomechanical properties, and some metabolic modulators that are involved in bone resorption were compared. The L5 lumbar vertebral body BMDs of the IBN, PEMF, and IBN + PEMF groups were 121.6%, 119.5%, and 139.6%; maximum loads were 111.4%, 112.7%, and 121.9%; and energy to failure was 130.8%, 129.2%, and 154.9% of the OVX model, respectively. The IBN + PEMF group had significantly lower levels of serum tartrate-resistant acid phosphatase 5b, and greater improvement in BMD, bone microarchitecture, and strength of the lumbar spine compared with monotherapy groups. Results showed that IBN + PEMF had a more favorable effect on the lumbar spine in this osteoporosis model than did either monotherapy. Bioelectromagnetics. 38:31-40, 2017. © 2016 Wiley Periodicals, Inc.

The Hip-Spine Effect: A Biomechanical Study of Ischiofemoral Impingement Effect on Lumbar Facet Joints

To assess the relation between ischiofemoral impingement (IFI) and lumbar facet joint load during hip extension in cadavers. Twelve hips in 6 fresh T1-to-toes cadaveric specimens were tested. A complete pretesting imaging evaluation was performed using computed tomography scan. Cadavers were positioned in lateral decubitus and fixed to a dissection table. Both legs were placed on a frame in a simulated walking position. Through a posterior lumbar spine approach L3-4 and L4-5 facet joints were dissected bilaterally. In addition, through a posterolateral approach to the hip, the space between the ischium and the lesser trochanter was dissected and measured. Ultrasensitive, and previously validated, piezoresistive force sensors were placed in lumbar facet joints of L3-4 and L4-5. Lumbar facet loads during hip extension were measured in native hip conditions and after simulating IFI by performing lesser trochanter osteotomy and lengthening. Four paired t-tests were performed comparing normal and simulated IFI on the L3-L4 and L4-L5 facet joint loads. After simulating IFI, mean absolute differences of facet joint load were 10.8N (standard error of the mean [SEM] ±4.53, P= .036) for L3-4 at 10° of hip extension, 13.71N (SEM ±4.53, P= .012) for L3-4 at 20° of hip extension, 11.49N (SEM ±4.33, P= .024) for L4-5 at 10° of hip extension, and 6.67N (SEM ±5.43, P= .245) for L4-5 at 20° of hip extension. A statistically significant increase in L3-4 and L4-5 lumbar facet joint loads of 30.81% was found in the IFI state as compared with the native state during terminal hip extension. Limited terminal hip extension due to simulated IFI significantly increases L3-4 and L4-5 lumbar facet joint load when compared with non-IFI native hips. This biomechanical study directly links IFI to increased lumbar facet loads and supports the clinical findings of IFI causing lumbar pathology. Assessing and treating (open or endoscopic) hip disorders that limit extension could have benefit in patients with concomitant lower back symptoms.

The influence of lumbar sympathetic ganglion radiofrequency thermocoagulation on the activation of microglia in rats with diabetic neuropathic pain

To observe the influence of lumbar sympathetic ganglion radiofrequency thermocoagulation on the activation of spinal microglia in rats with diabetic neuropathic pain (DNP). Thirty-six painful diabetic Sprague-Dawley rats induced by 60 mg/kg streptozotocin (STZ) intraperitoneal injection were randomly divided into diabetic neuropathic pain group (group DNP, n=12), Sham operation group (group Sham, n=12) and radiofrequency thermocoagulation group (group R, n=12). Meanwhile another 12 age-matched rats were allocated as normal control group (group N), rats in group N received intraperitoneal injection of equal volume of normal saline. Twenty-eight days after STZ injection, rats in group R received L3 lumbar sympathetic ganglia radiofrequency thermocoagulation on the left side under X-ray guideline after anesthesia with damage time 60 s and damage temperature 60 ℃. Rats in group Sham received puncture positioning, but not thermocoagulation therapy. The mechanical paw withdrawal threshold (PWT) were performed before STZ injection, 7, 14, 21, 28 days after STZ injection and 1, 3, 5, 7, 14 days after radiofrequency thermocoagulation, respectively. Blood glucose were performed before STZ injection, 3, 28 days after STZ injection and 1, 14days after radiofrequency thermocoagulation. After the final behavioral testing, L3-L5 spinal cord tissues were removed to exam the expression of microglia marker OX42 by Western blotting and immunofluorescence technique, and the changes in the expression of inflammation factor IL-1β, IL-6, TNF-α were detected by ELISA technique. Compared with group N, after 14, 21, 28 days of STZ injection and 1, 3, 5, 7, 14 days of radiofrequency thermocoagulation, the PWT of group DNP and group Sham decreased significantly (P<0.05); Before radiofrequency thermocoagulation, the PWT of rats in group DNP was (3.84±0.83) g, the PWT of rats in group R was (4.45±0.88) g, there was no statistically significant difference between group DNP and group R (t=1.514, P>0.05), but after radiofrequency thermocoagulation, compared with DNP group, the PWT of rats in group R increased significantly (P<0.05), and lasted to 14 d after radiofrequency thermocoagulation. The ratio of spinal microglia marker OX42 and GAPDH, the expression of inflammation factor IL-1β, IL-6, and TNF-α in group N were 0.074±0.023, (35.93±6.16) pg/ml, (92.11±13.23) pg/ml, and (169.50±22.64) pg/ml, respectively. The ratio of spinal microglia marker OX42 and GAPDH, the expression of inflammation factor IL-1β, IL-6, and TNF-α in group DNP were 1.023±0.185, (73.82±9.25) pg/ml, (155.33±21.82) pg/ml, and (298.30±33.21) pg/ml, respectively. The ratio of spinal microglia marker OX42 and GAPDH, the expression of inflammation factor IL-1β, IL-6, and TNF-α in group Sham were 0.951±0.103, (73.00±7.54) pg/ml, (151.02±24.26) pg/ml, and (294.01±36.37) pg/ml, respectively. The ratio of spinal microglia marker OX42 and GAPDH, the expression of inflammation factor IL-1β, IL-6, and TNF-α in group R were 0.563±0.019, (51.81±7.36) pg/ml, (123.24±16.13) pg/ml, and (229.23±29.16) pg/ml, respectively. Compared with group N, the expression of spinal microglia marker OX42 and inflammation factor IL-1β, IL-6, and TNF-α in group DNP, group Sham and group R increased significantly (F=7.501, 348.698, 568.021, 145.110, all P<0.05). Compared with DNP group, the expression of spinal microglia marker OX42 and inflammation factor IL-1β, IL-6, and TNF-α of group R reduced significantly (all P<0.05). The lumbar sympathetic ganglion radiofrequency thermocoagulation can alleviate diabetic neuropathic pain. The mechanism may relate with the inhibition of spinal microglia activation and the lower expression of inflammation factor.

Intercostal Artery Reconstruction: The Simple and Effective Technique on Spinal Cord Protection during Thoracoabdominal Aortic Replacement

To retrospectively analyze the role of intercostal artery reconstruction in the spinal cord protection for patients undergoing extensive thoracoabdominal aortic aneurysm repair. From August 2007 to 2014, thoracoabdominal aortas (Crawford II) of 81 consecutive patients with mean age 39.4 ± 10.32years were repaired. Seventy-three of these patients (90.12%) were diagnosed with aortic dissection in our group, 25 (30.86%) with Stanford type A dissection and 48 (59.26%) with Stanford B aortic dissection. All 25 patients with type A dissection have previously undergone surgical procedures which include Bentall's procedures in 11 cases, ascending aortic replacement in 6 cases, and total aortic arch replacement in 8 cases. All procedures were performed under profound hypothermia with interval cardiac arrest after making a thoracoabdominal incision. Extracorporeal circulation was instituted with 2 arterial cannulae and a single venous cannula in the right atrium. T6-T12 intercostal arteries and L1 and L2 lumbar arteries were formed to a neo-intercostal artery in place and were connected to an 8mm branch for maintaining spinal cord blood perfusion. Visceral arteries were joined into a patch and anastomosed to the end of the main graft. The left renal artery was anastomosed to an 8mm branch or joined to the patch. The other 10mm branches were anastomosed to iliac arteries. With 100% follow-up, early mortality was 7.4%. Six deaths were recorded; 1 patient died of cerebral hemorrhage, 3 of renal failure, 1 of heart failure because of myocardial infarction, and the last one died from the rupture of celiac artery dissection. The rate of postoperative spinal cord deficits was 3.7%, 2 patients with paraplegia and 1 patient with paraparesis. None had bladder or rectum dysfunction. Neo-intercostal arteries were clogged in 12 patients within follow-up period and formed pseudoaneurysm in 2 patients with Marfan syndrome. The mean survival time in this group was 54.22 ± 3.03months (95% confidence interval 44.37-59.90months) with survival rate of 92.37% after 1year, 89.02% after 2years, and 85.54% after 5years. All patients were free from spinal cord deficits. Intercostal artery reconstruction is an effective technique for spinal cord protection in patients with the thoracoabdominal aortic repair. It can achieve favorable results and avoid spinal cord deficits with long-term follow-up.

Evaluation of a novel tool for bone graft delivery in minimally invasive transforaminal lumbar interbody fusion.

Study designDisk material removed (DMR) during L4-5 and L5-S1 transforaminal lumbar interbody fusion (T-LIF) surgery was compared to the corresponding bone graft (BG) volumes inserted at the time of fusion. A novel BG delivery tool (BGDT) was used to apply the BG. In order to establish the percentage of DMR during T-LIF, it was compared to DMR during anterior diskectomy (AD). This study was performed prospectively.Summary of background dataMinimal information is available as to the volume of DMR during a T-LIF procedure, and the relationship between DMR and BG delivered is unknown. BG insertion has been empiric and technically challenging. Since the volume of BG applied to the prepared disk space likely impacts the probability of arthrodesis, an investigation is justified.MethodsA total of 65 patients with pathology at L4-5 and/or L5-S1 necessitating fusion were treated with a minimally invasive T-LIF procedure. DMR was volumetrically measured during disk space preparation. BG material consisting of local autograft, BG extender, and bone marrow aspirate were mixed to form a slurry. BG slurry was injected into the disk space using a novel BGDT and measured volumetrically. An additional 29 patients who were treated with L5-S1 AD were compared to L5-S1 T-LIF DMR to determine the percent of T-LIF DMR relative to AD.ResultsDMR volumes averaged 3.6±2.2 mL. This represented 34% of the disk space relative to AD. The amount of BG delivered to the disk spaces was 9.3±3.2 mL, which is 2.6±2.2 times the amount of DMR. The BGDT allowed uncomplicated filling of the disk space in <1 minute.ConclusionThe volume of DMR during T-LIF allows for a predictable volume of BG delivery. The BGDT allowed complete filling of the entire prepared disk space. The T-LIF diskectomy debrides 34% of the disk relative to AD.

The morphology and clinical significance of the intraforaminal ligaments at the L5–S1 levels

Background ContextThe extraforaminal ligaments between the L5 and S1 lumbar spinal nerves and the tissues surrounding the intervertebral foramina have been well studied. However, little research has been undertaken to describe the local anatomy of the intraforaminal portion of the L5–S1 spine and detailed anatomical studies of the intraforaminal ligaments (IFLs) of the L5–S1 have not been performed. PurposeThe objective of this study was to identify and describe the IFLs in relation to the L5–S1 intervertebral foramen (IVF) and to determine their clinical significance. Study DesignA dissection-based study of five embalmed and five fresh-frozen human cadavers was carried out. MethodsTwenty L5–S1 intervertebral foramina from five embalmed cadavers and five fresh cadavers were studied, and the IFLs were identified. The quantity, morphology, origin, insertion, and spatial orientation of the IFLs in the L5–S1 region were observed. The length, width, diameter, and thickness of the ligaments were measured with a vernier caliper. This study has been supported by grants from the National Natural Science Foundation of China (Grant No. 31271286) without potential conflict of interest-associated biases in the text of the paper. ResultsThe IFLs could be found from the entrance zone (inside) to the exit zone (outside) of the L5–S1 IVF. These ligaments were found to be of two types: a radiating ligament, which connected the nerve root sleeves that radiated to the transverse processes and wall of the IVF, and a transforaminal ligament, which connected the structures around the IVF. In our study, the radiating ligaments were found more often than the transforaminal ligaments. ConclusionsThe results demonstrate that IFLs are common structures in the IVF and that there are two types of IFLs: the transforaminal ligaments and the radiating ligaments. Transforaminal ligaments may be the potential cause of back pain. The radiating ligaments may contribute to dura laceration and epidural hemorrhage during endoscopic spinal adhesiolysis through the sacral hiatus, and an appreciation of this relationship might help reduce the risk of such complications.

A Study of Sacral Anthropometry to Determine S1 Sacral Screw Placement for Spinal Lumbosacral Fixation in the Korean Population

Introduction There are various methods of S1 pedicular screw fixation, and every method has its own advantages and disadvantages. But, anatomical variation of the posterior superior iliac spine (PSIS) was not considered in any method. Therefore, little is known about the safe angle for screw fixation in the Asian population. Material and Methods We performed our study in 160 sacra including the pelvic ring obtained from 80 Korean cadavers. The bony measurements were obtained by performing 1 mm computed tomography (CT) cuts from the L5 lumbar vertebra to the pelvic ring and excluding other structures. We evaluated the incidence of anatomic variation of the PSIS and measured the safe marginal length and angle for screw fixation considering the PSIS and course of the external iliac vein, using a Korean sacrum model. Results Our study showed that the closed type of PSIS is more frequent in males than in females. The optimal angle for screw fixation is 16.91 ± 6.85 (°), while the Lt. side S1 pedicle insertion angle (SPIA) is 16.00 ± 6.20 (°). The average Korean optimal screw length is 58.35 ± 14.90 (cm) for the Rt. Side and 55.89 ± 16.16 (cm) for the Lt. side. Conclusion With reference to these parameters, the optimal screw length and angle can be chosen and bicortical anteromedial screw fixation can be easily and safely performed.