L5 Lumbar Research Articles

Motor and Sensory Impairments of the Lower Extremities After L2 Nerve Root Transection During Total en Bloc Spondylectomy.

Retrospective study. The purpose of this study was to examine motor and sensory impairments of the lower extremities after L2 nerve root transection during total en bloc spondylectomy (TES) for spinal tumors. At our institute, for TES at L3 to L5 lumbar levels, the nerve roots are preserved. However, at the level of L1 and L2, the vertebral resection and spinal reconstruction via a posterior approach is employed with transection of the nerve roots during dissection and resection of the vertebra. This study included 13 patients who had undergone TES for spinal tumors involving L2 between 2007 and 2016. Postoperative motor function of the lower extremities was quantified using the Manual Muscle Testing grade for the iliopsoas (IP) and quadriceps femoris (QF) muscles, and a grade of the modified Frankel Classification. Postoperative sensory impairment was quantified by the sites of lower extremity pain and numbness. An initial decrease in strength of the IP and QF muscles in more than 60% of the patients, with a decline in the modified Frankel grade in 76.9%, was observed at 1-week after surgery. All patients recovered by the final follow-up, with 12 of the 13 patients walking without a gait aid. The other patient, who had undergone a bilateral dissection of L3 nerve root during TES of L2 and L3, had a mild QF muscle weakness, requiring a cane for walking. Eleven of 13 patients developed pain or numbness in the groin or thigh area after surgery, with the most common area being the anterior aspect of the thigh. Although IP and QF weakness was observed in the majority of patients who underwent bilateral transection of L2 nerve roots during TES, these deficits recovered over time and did not finally affect activities of daily living. 4.

The Use of L2 and L3 Lumbar Sympathetic Blockade for Cancer-Related Pain, an Experience and Recommendation in the Oncologic Population.

The sympathetic nervous system has a recognized role in transmission of pain, and the lumbar sympathetic blockade is intended to provide analgesia. We share our experiences of lumbar sympathetic blockade in the treatment of cancer-related pain. We performed a retrospective analysis of patients with cancer-related pain in the back, abdomen, pelvis, or legs treated at Memorial Sloan Kettering Cancer Center between 2000 and 2018 undergoing lumbar sympathetic blockade at L2 or L3. Blocks were accomplished by injection of local anesthetic or local anesthetic with steroid under fluoroscopy. We measured numerical rating scale scores, percent relief, and relief time. The primary end point was defined as "effective" or "ineffective" pain relief. Effective pain relief was defined as ≥30% relief for at least one day. We identified 124 data points of lumbar sympathetic blockade at L2 or L3, of which 57 were with complete data and used for analysis. Peri-injection, 42 data points had active disease whereas 15 were in remission. Lumbar sympathetic blockade was 67% effective in the back pain cohort, 82% effective in the abdominopelvic pain cohort, and 75% effective in the leg pain cohort. Seventeen data points went on to neurolysis, two to neuromodulation, and eight to intrathecal pump implantation. Lumbar sympathetic blockade is effective for back, abdominopelvic, and leg pain related to cancer and its treatments. Future research should be aimed at refining its role within multimodal pain management.

Classification of foot drop gait characteristic due to lumbar radiculopathy using machine learning algorithms

Background: Recently, the study of walking gait has received significant attention due to the importance of identifying disorders relating to gait patterns. Characterisation and classification of different common gait disorders such as foot drop in an effective and accurate manner can lead to improved diagnosis, prognosis assessment, and treatment. However, currently visual inspection is the main clinical method to evaluate gait disorders, which is reliant on the subjectivity of the observer, leading to inaccuracies.Research question: This study examines if it is feasible to use commercial off-the-shelf Inertial measurement unit sensors and supervised learning methods to distinguish foot drop gait disorder from the normal walking gait pattern.Method: The gait data collected from 56 adults diagnosed with foot drop due to L5 lumbar radiculopathy (with MRI verified compressive pathology), and 30 adults with normal gait during multiple walking trials on a flat surface. Machine learning algorithms were applied to the inertial sensor data to investigate the feasibility of classifying foot drop disorder.Results: The best three performing results were 88.45%, 86.87% and 86.08% accuracy derived from the Random Forest, SVM, and Naive Bayes classifiers respectively. After applying the wrapper feature selection technique, the top performance was from the Random Forest classifier with an overall accuracy of 93.18%.Significance: It is demonstrated that the combination of inertial sensors and machine learning algorithms, provides a promising and feasible solution to differentiating L5 radiculopathy related foot drop from normal walking gait patterns. The implication of this finding is to provide an objective method to help clinical decision making.

MON-319 A Young Woman with Familial Isolated Primary Hyperparathyroidism Due to Parathyroid Adenoma and Atrophic Gastritis

Background: High levels of gastrin and parathyroid hormone (PTH) can coexist outside the multiple endocrine neoplasia (MEN) kindred syndromes. There is significant non-causal association between chronic autoimmune atrophic gastritis (CAAG) and primary hyperparathyroidism (PHPT). Prevalence of PHPT is increased in patients with CAAG (8.4 vs 1–3%, general population).1,2 These studies excluded people with familial PHPT, MEN1 syndrome, those on proton pump inhibitors, H. pylori infection and renal failure. Some studies show an association between gastric carcinoid type 1 tumor (GC-1) and PHPT.3 No data is available on association between hypergastrinemia, gastritis and familial isolated HPT (FIHPT) Case: A 37-year-old female with hypothyroidism due to Hashimoto’s thyroiditis and premature ovarian insufficiency was incidentally found to have hypercalcemia with total calcium of 10.8 mg/dL (8.9–10.4), ionized calcium 1.4 mg/dL (1.14–1.33), 24 hour urine calcium of 0.252 g/d (0.032–0.368), urine creatinine 0.56 g/24hr (0.78–2.31), urine volume 1650 mL. 25 OH Vitamin D was low at 17 pg/ml. She also had elevated chromogranin A level at 541 ng/mL (0–95), gastrin level of 1522 pg/mL (0–100) and Vitamin B12 level of 299 pg/mL (> 201 acceptable), negative intrinsic factor and antiovarian antibody. There is a strong family history of primary hyperparathyroidism in mother and sister and hypercalcemia in brother and niece (unknown workup). Parathyroid scan showed ectopic parathyroid adenoma, with mild focal uptake a few centimeters inferior to the lower pole of the right thyroid gland. Bone density scan showed osteopenia at L1- L4 lumbar spine with T score -2.1 and BMD of 0.924 g/cm2. Genetic test was negative for CASR, CDC73, CDKN1B, MEN1, RET amplified by long-range PCR and sequenced by Pacific Biosciences SMRT. Upper GI endoscopy with gastric biopsy showed severe chronic atrophic gastritis with extensive intestinal metaplasia associated with diffuse neuroendocrine cell hyperplasia within the crypts. She was diagnosed with familial isolated primary hyperparathyroidism with chronic atrophic gastritis. Conclusion: As far as we know, there are no reported cases documenting chronic atrophic gastritis occurring with familial isolated primary hyperparathyroidism. This case highlights that in patients with FIHPT, hypergastrinemia and gastritis can occur independent of MEN -1 syndrome.

Aging of mouse intervertebral disc and association with back pain.

With the increased burden of low back pain (LBP) in our globally aging population there is a need to develop preclinical models of LBP that capture clinically relevant features of physiological aging, degeneration, and disability. Here we assess the validity of using a mouse model system for age-related LBP by characterizing aging mice for features of intervertebral disc (IVD) degeneration, molecular markers of peripheral sensitization, and behavioral signs of pain. Compared to three-month-old and one-year-old mice, two-year-old mice show features typical of IVD degeneration including loss of disc height, bulging, innervation and vascularization in the caudal lumbar IVDs. Aging is also associated with the loss of whole-body bone mineral density in both male and female mice, but not associated with percent lean mass or body fat. Additionally, two-year-old mice have an accumulation of TRPA1 channels and sodium channels NaV1.8 and NaV1.9 in the L4 and L5 lumbar dorsal root ganglia consistent with changes in nociceptive signaling. Lastly, the effect of age, sex, and weight on mobility, axial stretching and radiating pain measures was assessed in male and female mice ranging from two months to two years in a general linear model. The model revealed that regardless of sex or weight, increased age was a predictor of greater reluctance to perform axial stretching and sensitivity to cold, but not heat in mice.

Surgical Approach of Cauda Equina Syndrome Secondary to L5 Lumbar Solitary Bone Plasmocytoma with Partial Resection and Lumbopelvic Fixation

AbstractThe solitary bone plasmacytoma is an uncommon cause of chronic lumbar pain. It belongs to a tumor group of plasmatic cells that usually disturbs the axial skeleton and can progress to multiple myeloma. The treatment of choice is radiotherapy; however, surgical management can also be done. Regardless of the no reliable data and little evidence, it is clear that the intervention is based on the classification systems of Enneking and Weinstein–Boriani–Biagini. This article will show a 66-year-old female patient with lumbar pain of 1 month with B symptoms. A solitary bone plasmacytoma diagnosis was made with pathology confirmation. A surgical procedure with improvement of symptoms was achieved, with 2 years of follow-up without relapse.

Solitary Osseous Plasmacytoma of a Lumbar Vertebrae with Systemic Involvement in a Dog

Background: Myeloma-related disorders are characterized by proliferation of neoplastic plasma cell or immature immunoglobulin secreting B-lymphocytes, and include multiple myeloma, M-macroglobulinemia and extra-medullary plasmacytoma (cutaneous or extra-cutaneous). Solitary osseous plasmacytoma (SOP) is considered an unique entity among extra-medullary extra-cutaneous plasmacytoma. It is an unusual neoplasia in dogs, predominantly found in middle-aged to older animals, with a higher incidence in bones of axial skeleton. Dogs with vertebral SOP present neurological signs related to spinal cord compression, but progression to multiple myeloma is related to a poor outcome. As in humans, progression to multiple myeloma occurs in most cases, although it may take months or years from its initial presentation. SOP´s biological behaviour, incidence and prognostic are rarely documented. Chemotherapy with melphalan and prednisolone represent the most used protocol for multiple myeloma. However, in SOP, the combination of chemotherapy with local approaches is controversial before the evidence of systemic disease. This paper aims at reporting a case of SOP in a lumbar vertebrae of a dog, with systemic involvement. Case: A 11-year old male mixed breed dog was attended presenting muscle weakness, lethargy, anorexia, adipsia and intense pain manifestation. The dog also presented multiple skin nodules, previously diagnosed as a plasmacytoma, through cytology. The dog´s poor clinical condition and aggressive temper, associated with suspicious of an advanced myeloma-related disorder, resulted in the decision for humanized euthanasia. At necropsy, a pale, friable and hemorrhagic mass was identified on the L3 lumbar vertebrae, associated with an osteolytic bone lesion and spinal cord compression. Histopathological analyses revealed proliferation of plasma cells, with pale perinuclear halo, moderate cellular pleomorphism, 10 binucleated cells and 10 mitotic figures per 10 high power fields, compatible with extramedullary plasmacytoma of the mature type, in the lumbar vertebrae (SOP). It was also seen myeloma-related lesions in the skin and subcutaneous, prostate, heart, superficial mandibular and axillary lymph nodesDiscussion: Solitary osseous plasmacytoma is a myeloma-related disorder rarely reported in dogs. Its biological behaviour is poorly characterized, however progression for multiple myeloma is common in humans and dogs, and it is related to a poor outcome. As the present report, systemic progression of SOP has been previously described and although an overt bone marrow infiltration was not detected, such possibility can not be excluded, once multiple myeloma distribution in the bone marrow is often multifocal. Although chemotherapy is the treatment of choice for multiple myeloma, its indication for SOP is conditioned to the evidence of systemic disease. It might delay tumour progression, but its early implementation may favor the selection of resistant neoplastic clones, making it ineffective when progression to multiple myeloma occurs. In humans radiotherapy is the treatment of choice for SOP, however it may be indicated in association to surgery. A retrospective study showed a higher survival rate in patients with SOP in the axial skeleton, which received surgical treatment combined with radiotherapy, if compared to those treated with surgery or radiotherapy alone. Decision for euthanasia was made based on the suspicious of advanced myeloma-related disorder, patient´s medical condition and aggressive temper, which limited diagnostic investigation and treatment.

Association of chronic degenerative arthritis related chronic low back pain with altered lumbar facet joint orientation

ObjectiveTo examine the relationship between changes in lumbar spine facet joint (FJ) orientation and chronic low back pain (CLBP). MethodsWe retrospectively analyzed lumbar spine CT and MRI images of 98 patients referred for localized paraspinal CLBP and 98 age-and sex-matched asymptomatic individuals as controls. They were divided into four age groups (A, <40; B, 41–50; C, 51–60; D, 61–70; and E, 71–80 years old, respectively). FJ orientations were evaluated at the L3-4, L4-5, and L5-S1 lumbar levels. ResultsFJ angle showed a statistically significant more sagittal orientation in CLBP patients than in control groups in lower lumbar spine segments. The overall mean FJ angles in CLBP groups including all age groups combined at L3-4, L4-5, and L5-S1 levels were 32.33 ± 4.5, 36.11 ± 2.9, and 37.4 ± 6.1, degrees, respectively. The FJ angles in control group for all ages were 32.21 ± 3.7, 38.01 ± 4.6, and 40.18 ± 6.8°, respectively. The differences in FJ angle were statistically significant at both L4-5 and L5-S1 levels between the control and the CLBP groups (p < 0.01). The FJ orientation from upper lumbar spine to lumbar sacral junction demonstrated a gradual more coronal orientation transition in all subjects but this trend was significantly less in CLBP patients. The mean FJ angles for the control group at age groups A, B, C, D, and E were 33.52 ± 3.8, 35.7 ± 4.5, 38.25 ± 2.4, 35.49 ± 4.1, and 38.13 ± 5.8, respectively, while those in the CLBP groups were 35.63 ± 2.4, 35.26 ± 3.6, 35.99 ± 5.1, 35.3 ± 4.3, and 35.17 ± 6.7, respectively. ConclusionThere is a significant association between a more sagittal FJ orientation and facetogenic CLBP in lower lumbar vertebral levels. There is also age-dependent decrease in FJ orientation in sagittal plane at lower lumbar spinal levels in control as well as CLBP groups, however, this decrease in the CLBP groups was significantly more pronounced. Whether this change was an adaptive remodeling or alterations associated with chronic FJ osteoarthropathy should warrant further longitudinal studies.

Plastic Energy Dissipation in Lumbar Spine Implants: A Contact Mechanics Point of View

In this study, an elastoplastic contact model is developed for L1–L5 lumbar spine implants. Roughness effect is included to estimate energy loss which is an indication of wear and subsequently the issue of metal debris in body. A Gaussian function is assumed for the distribution of asperities. The contact surfaces of the implants are assumed to be spherical caps. Subsequently, a least-square approach is applied to obtain an approximate expression for the contact force using the data from integration over contact zone. The energy loss is calculated, next, which is due to plastic deformations of asperities. The numerical results indicate that for a given loading–unloading condition, the amount of energy dissipation increases in L1–L4 lumbar spine implants, while it decreases from L4 to L5 implants. The implants geometrical specifications are chosen to cover a wide range of patients' age. Finally, a closed-form expression is obtained for the plastic energy dissipation per cycle in terms of plasticity index for the lumbar spine L4, as the worst-case scenario. Such a function can serve as a very useful tool for implant designers and manufacturers.

Evaluation of damage to the lumbar spine vertebrae L5 by finite element analysis

Bone metastasis to the spine, pelvis or hip in patients with prostate cancer is a pathology that occurs in approximately 80% of cases. Metastases in the spine can cause pain, instability and neurological injuries. Therefore, it is relevant to evaluate when critical conditions have been reached and the structural integrity of the bone is compromised. Numerical methods based on patient data, obtained through post-processing of medical images, provide a tool to model the complexity of the biological tissue material. Computed axial tomography (CT) together with segmentation tools allows the reconstruction of 3D bone models that include mechanical properties, and that represents the anisotropic condition of bone structures. In this work, we present the L5 lumbar vertebra model of a patient affected by metastases and evaluate biomarkers to indicate the level of damage, compared with the reference case of healthy bone in an initial stage.

Once-Weekly Teriparatide Treatment Prevents Microdamage Accumulation in the Lumbar Vertebral Trabecular Bone of Ovariectomized Cynomolgus Monkeys

The effect of teriparatide treatment on microdamage accumulation has yet to be examined in animal studies. The purpose of this study was to investigate the effect of once-weekly teriparatide treatment on bone microdamage accumulation and the relationship between microdamage parameters and bone mass, architecture, turnover, and collagen cross-linking in the lumbar vertebral trabecular bone of ovariectomized (OVX) cynomolgus monkeys. Female monkeys were divided into four groups (n = 18–20 per group): (1) SHAM group, (2) OVX group, (3) OVX with 1.2 µg/kg once-weekly teriparatide group (LOW group), (4) OVX with 6.0 µg/kg once-weekly teriparatide group (HIGH group). After 18 months, all animals were double-labeled with calcein for histomorphometry. L3 and L7 lumbar vertebrae were harvested and analyzed for differences in histomorphometry, microdamage, and collagen cross-linking. The iliac crest was also analyzed for differences in bone turnover. In the OVX group, cancellous bone mass was reduced and microdamage accumulation was increased as compared with the SHAM control. Once-weekly teriparatide at both doses prevented the decrease in bone mass and increase in microdamage accumulation, and improved the distribution of collagen cross-linkage types. Regression analyses indicated that decreased microdamage accumulation was associated with reduced non-enzymatic cross-link pentosidine rather than increased cancellous bone mass or enzymatic cross-links. These findings suggest that once-weekly teriparatide treatment decreases microdamage accumulation by recovering the balance in collagen cross-links.

Research on Spinal Lumbar Sacral Degeneration Finite Element Model

Recent research has shown that lumbar disease has become common in China. Since the structure of the lumbar spine is extremely complex, a finite element analysis method was used to perform biomechanical simulation and analysis of stress and strain on the L3–L4 lumbar segment to provide both a scientific and theoretical basis for clinical diagnosis and medical research. The MC volume-rendering 3D reconstruction method was the first step to accurately constructing the finite element model of the L3–L4 lumbar sacral segment, which was simulated prior to the addition of the ligaments, fibrous ring, and other major spinal tissue. The finite element model network was classified and the material properties of the corresponding parts were described. According to the normal model, careful simulation and deformation were performed, in addition to intervertebral disc degeneration in various cases. We have provided a detailed and professional analysis of the biomechanical properties, providing a powerful biomechanical basis for the diagnosis of intervertebral disc bulge and degeneration.

Postural and Metabolic Benefits of Using a Forearm Support Walker in Older Adults With Impairments

ObjectiveTo investigate the postural and metabolic benefits a walker with adjustable elbow support (LifeWalker [LW]) can provide for ambulation in population with impairment. The clinical outcomes from the elbow support walker will be compared with standard rollator (SR) and participants predicate device (PD). DesignCase-crossover study design. SettingClinical laboratory. ParticipantsIndividuals aged between 18 and 85 years using a rollator walker as primary mode of assistance and certified as medically stable by their primary physician. Participants (N=30; 80% women [n=24]) recruited from a convenient sample provided voluntary consent and completed the study. InterventionNot applicable. Main Outcome MeasuresThe trunk anterior-posterior (AP) sway (during the 10-meter walk test), oxygen consumption (during the 6-minute walk test), the mean forearm load offloaded to the elbow support as percentage of body weight, and mean peak hand grip load (during the 25-meter walk test) were measured. ResultsAmbulating with a LW led to (1) reduced trunk sway in the AP direction [(ZLW vs PD= −2.34, P=.018); (ZLW vs SR= −3.461, P=.001)]; (2) reduced erector spinae muscle activation at the left lumbar L3 level [(ZLW vs PD= −2.71, P=.007); (ZLW vs SR= −1.71, P=.09)]; and (3) improved gait efficiency [(ZLW vs PD= −2.66, P=.008) Oxygen cost; (ZLW Vs. SR= −2.66, P=.008) Oxygen cost]. Participants offloaded between 39% and 46% of their body weight through the elbow support armrest while ambulating with the LW. Irrespective of the walker used, participants exerted ∼5%-6% of their body weight in gripping the walker handles during walking. ConclusionsUsing the forearm support-based LW led to upright body posture, offloaded portions of body weight from the lower extremity, and improved gait efficiency during ambulation in comparison to the SR and the participants’ own PD. Further studies focusing on population-specific benefits are recommended.

Segmental Lordosis of the Spondylolytic Vertebrae in Adolescent Lumbar Spondylolysis: Differences between Bilateral L5 and L4 Spondylolysis.

Study DesignRetrospective study.PurposeThis study aimed to investigate whether segmental lumbar hyperlordosis of the affected vertebra in patients with spondylolysis occurs only at L5 or also occurs at L4.Overview of LiteratureTo the best of our knowledge, increase in segmental lordosis of the spondylolytic vertebrae has only been investigated in bilateral L5 spondylolysis; it has not been examined at different levels of bilateral spondylolysis. According to the characteristics of segmental lordosis in bilateral L5 spondylolysis, patients with bilateral L4 spondylolysis may also have increased segmental lordosis of the L4 vertebra.MethodsPatients with bilateral spondylolysis of the L5 or L4 vertebra in 2013–2015 were retrospectively identified from the hospital database. Standing lateral lumbar radiographs were assessed for the angle of segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis. The differences in segmental lordosis of the L5 and L4 vertebra, sacral slope, and lumbar lordosis were determined using non-paired Student t-test.ResultsOverall, 15 cases of bilateral L4 spondylolysis and 41 cases of bilateral L5 spondylolysis satisfied the inclusion and exclusion criteria. Lordosis of the L4 vertebra was significantly greater in the bilateral L4 spondylolysis group (24.2°±7.0°) than that in the L5 spondylolysis group (20.3°±6.1°, p=0.047). Lordosis of the L5 vertebra was significantly lower in the L4 spondylolysis group (27.7°±8.2°) than that in the L5 spondylolysis group (32.5°±7.3°, p=0.040). The sacral slope and lumbar lordosis did not significantly differ between the groups.ConclusionsAdolescent patients with bilateral spondylolysis have segmental hyperlordosis of the affected vertebra not only at the L5 level but also at the L4 level.

3D Chemical Shift-Encoded MRI for Volume and Composition Quantification of Abdominal Adipose Tissue During an Overfeeding Protocol in Healthy Volunteers.

Overweight and obesity are major worldwide health concerns characterized by an abnormal accumulation of fat in adipose tissue (AT) and liver. To evaluate the volume and the fatty acid (FA) composition of the subcutaneous adipose tissue (SAT) and the visceral adipose tissue (VAT) and the fat content in the liver from 3D chemical-shift-encoded (CSE)-MRI acquisition, before and after a 31-day overfeeding protocol. Prospective and longitudinal study. Twenty-one nonobese healthy male volunteers. A 3D spoiled-gradient multiple echo sequence and STEAM sequence were performed at 3T. AT volume was automatically segmented on CSE-MRI between L2 to L4 lumbar vertebrae and compared to the dual-energy X-ray absorptiometry (DEXA) measurement. CSE-MRI and MR spectroscopy (MRS) data were analyzed to assess the proton density fat fraction (PDFF) in the liver and the FA composition in SAT and VAT. Gas chromatography-mass spectrometry (GC-MS) analyses were performed on 13 SAT samples as a FA composition countermeasure. Paired t-test, Pearson's correlation coefficient, and Bland-Altman plots were used to compare measurements. SAT and VAT volumes significantly increased (P < 0.001). CSE-MRI and DEXA measurements were strongly correlated (r = 0.98, P < 0.001). PDFF significantly increased in the liver (+1.35, P = 0.002 for CSE-MRI, + 1.74, P = 0.002 for MRS). FA composition of SAT and VAT appeared to be consistent between localized-MRS and CSE-MRI (on whole segmented volume) measurements. A significant difference between SAT and VAT FA composition was found (P < 0.001 for CSE-MRI, P = 0.001 for MRS). MRS and CSE-MRI measurements of the FA composition were correlated with the GC-MS results (for ndb: rMRS/GC-MS = 0.83 P < 0.001, rCSE-MRI/GC-MS = 0.84, P = 0.001; for nmidb: rMRS/GC-MS = 0.74, P = 0.006, rCSE-MRI/GC-MS = 0.66, P = 0.020) DATA CONCLUSION: The follow-up of liver PDFF, volume, and FA composition of AT during an overfeeding diet was demonstrated through different methods. The CSE-MRI sequence associated with a dedicated postprocessing was found reliable for such quantification. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1587-1599.

Metformin attenuates increase of synaptic number in the rat spinal dorsal horn with painful diabetic neuropathy induced by type 2 diabetes: a stereological study.

In our previous study, we have shown that number of synapses in the L5 segment of spinal dorsal horn increased significantly in a rat model of painful diabetic neuropathy (PDN) induced by high-dose of streptozotocin (an animal model of type 1 diabetes). The aims of this study were: (1) to determine whether high fat diet/low dose streptozotocin-diabetes, a rat model for type 2 diabetes, related PDN was also associated with this synaptic plasticity, (2) to reveal the range of this synaptic plasticity change occurred (in the whole length of spinal dorsal horn or only in the L5 lumbar segment of spinal dorsal horn) and (3) to discover whether treatment with metformin had effect on this synaptic plasticity. Male adult Sprague-Dawley rats were randomly allocated into the control group (n = 7), the PDN group (n = 6) and the PDN treated with metformin (PDN + M) group (n = 7), respectively. 28days after medication, synaptic and neuronal numbers in the whole length of spinal dorsal horn or in 1mm length of the L5 segment of spinal dorsal horn were estimated by the optical disector (a stereological technique). Compared to the control group and the PDN + M group, number of synapses in the L5 segment of spinal dorsal horn increased significantly in the PDN group (P < 0.05). There was no significant change between the control group and the PDN + M group in terms of the parameters in the L5 segment of the spinal dorsal horn (P > 0.05). Parameters of the whole length of spinal dorsal horn showed no significant changes (P > 0.05). Our results suggest that high fat diet/low dose streptozotocin diabetes related PDN is also associated with a numerical increase of synapses in the L5 segment of spinal dorsal horn but not in the whole length of spinal dorsal horn. Furthermore, the analgesic effect of metformin against PDN is related to its inhibition of numerical increase of synaptic number in the rat spinal dorsal horn.

Variation in human vertebral body strength for vertebral body samples from different locations in segments L1–L5

BackgroundThe human spine, in particular the lumbar spine, is subject to significant compressive and bending stresses, which affect the structure of the bone tissue of the vertebrae. The more heterogeneous the structure of the spongy bone tissue, the less resistant the whole vertebral body. It is therefore necessary to establish variations in bone strength parameters within one particular vertebral body. MethodsThe research material comprised human L1–L5 lumbar vertebrae sampled from 15 donors aged 29–35. A total of 975 samples prepared from the collected material were subjected to compressive and bending strength tests. The samples for the tests were collected from carefully selected locations in order to discover the strength properties of various parts of the vertebral body. FindingsIn the case of sample 2 (located in the posterior part of the vertebra, at mid-height) the stress values were the lowest and there were statistically significant differences compared to other samples. Moreover the value of compressive force in this case was lower for vertebrae with higher numbers. Top and bottom samples demonstrated statistically significant higher mean values of destructive stress. In terms of the bending strength test, the mean value of destructive stress in all lumbar vertebrae for all samples increased for vertebrae with higher numbers. InterpretationThe spongy tissue in healthy vertebral bodies has a very heterogeneous structure. This may be due to the presence of the nutrient canal and the arc structure allowing more springy movement and improved transfer of loads by the vertebral body.

Ectopic lumbar kidney: a rare presentation

Ectopic kidney is a rare developmental anomaly. Such kidneys may be asymptomatic or present with vague symptoms or remain unknown during the lifetime. Early detection and recognition of an ectopic kidney can prevent long-term complications. We report a 70-year-old lady with ectopic right kidney who presented with intermittent episodes of lower abdominal pain since one month 1 month. On clinical evaluation a tender lump was palpable in the right lower quadrant of the abdomen. Sonography revealed empty right renal fossa with normally present left kidney. A mass was detected in the right lower abdomen, with probability of ectopic kidney. Further, Multislice computed tomography with 3-D reconstruction demonstrated ectopic right kidney at the level of L4 to L5 lumbar vertebrae. Urine examination revealed pyuria. The patient was managed on empirical antibiotics for UTI with supportive and symptomatic therapy. On the next day, clinically the lump regressed significantly (Dietl's crises) in size, and the tenderness also reduced. The urine culture report grew Escherichia coli. Patients presenting with lower abdominal pain, and a palpable lump in the lower abdomen, one must include ectopic kidney in the differential diagnosis.

Thursday, September 27, 2018 1:05 PM–2:05 PM Lumbar Spine Surgery: What You Need to Know: 112. Patient Reported Functional Outcome (PRFO) following MIS decompression without fusion in potentially unstable lumbar conditions

BACKGROUND CONTEXT Minimally invasive surgical techniques are reported to maintain spinal stability while accomplishing adequate clinical decompression. Degenerative conditions affecting the lumbar spine are frequent occurrences and often require surgical treatment. Spondylolisthesis with or without facet cysts may present potentially unstable conditions and fusion can be considered as adjuncts to decompression. However, can use of MIS techniques in selected patients preclude use of fusion? PURPOSE Evaluate PRFO and perioperative morbidity using MIS techniques for lumbar decompression in potentially unstable lumbar conditions. STUDY DESIGN/SETTING Retrospective review of prospectively collect data from rural academic medical center. PATIENT SAMPLE A total of 82 L4-5 lumbar decompression patients 24 with Grade I spondylolisthesis selected from total group of 384 lumbar decompressions over 7 year period. OUTCOME MEASURES VAS back & leg pain, Oswestry Disability Index, PHQ-9. METHODS From a total cohort of 384 patients a study cohort of 24 Grade I spondylolisthesis patients was matched with 58 nonspondylolisthesis patients requiring L4-5 decompression for neural compressive symptoms. PRFO measures were collected preop, at 1, 4, 10 and 24 months postoperatively. Perioperative demographics were collected. IRB approval was obtained. RESULTS There was no significant difference in follow-up time (mean 49.3 months) or PRFO within the study cohorts – spondylolisthesis versus nonspondylolisthesis. Each group demonstrated a significant functional improvement preop to 24 months postop in all categories. Spondylolisthesis patients were significantly older (72.4 years vs. 55.9; p CONCLUSIONS Lumbar decompression for grade I spondylolisthesis related spinal stenosis can be accomplished safely without fusion in cases of relative preoperative stability. Wide MIS decompression does not appear to compromise segmental stability and can be accomplished with minor patient morbidity, largely as an outpatient experience with anticipated improvement in patient reported functional outcomes of back and leg pain, ODI and PHQ-9. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: basic science of spinal fusion: 238. The effects of varenicline (Chantix) on lumbar spinal fusion in a rat model

BACKGROUND CONTEXT Smoking is detrimental to obtaining a solid spinal fusion mass with previous studies demonstrating that tobacco use is associated with pseudoarthrosis in patients undergoing spinal fusions. Additionally, smoking is an important predictor of increased dissatisfaction, decreased walking ability, increased pain medication use, and poorer quality of life scores in patients after spine surgery when compared to nonsmokers. Accordingly, physicians make significant efforts toward helping patients discontinue their use of nicotine products. Varenicline is a nonscheduled prescription medication that works as a partial agonist of nicotinic acetylcholine receptors, the same receptors activated during smoking and tobacco use, and is used as a pharmacologic adjunct to aid patients in smoking cessation. However, no clinical or basic science studies to date have characterized if varenicline has the same negative effects as nicotine on spinal fusion, consolidation, and bone healing. PURPOSE As a partial agonist of nicotine receptors, our study aimed to elucidate whether varenicline affects the rate or quality of spinal fusion. STUDY DESIGN/SETTING Manual, radiographic, and biomechanical testing. PATIENT SAMPLE A total of 14 Lewis rats undergoing L4-5 lumbar spinal fusion. OUTCOME MEASURES Gross motion, radiographic density, peak load, and stiffness of fusion mass METHODS According to our IACUC approved protocol, fourteen male Lewis rats underwent tail amputation to create an autogenous bone graft from the tailbone followed by a lumbar L4-5 posterior spinal fusion procedure. Postsurgery, rats were randomly separated into two experimental groups receiving either daily subcutaneous injections of human dose (1mg/kg daily in saline) varenicline or saline (placebo) for 12 weeks postsurgery. Spine samples were then explanted and fusion was determined via manual palpation of segments by two independent blinded observers. Radiographic analysis of fusion was performed via high-resolution radiographs evaluating bridging fusion mass. Rat lumbar spinal fusion units were then tested in 4-point bending to evaluate stiffness and peak load before failure. Comparisons were made between groups (significance at p RESULTS At three months postsurgery, twelve out of fourteen rats demonstrated lumbar spine fusion (86% fused) with no difference in fusion rate between the varenicline and control groups (6/7, 86%). Fusion rate as detected by manual palpation indicated no motion in the desired fusion segment. Findings were further supported with faxitron radiography demonstrating six out of seven rats (86%) having complete fusion consisting of contiguous transverse processes bilaterally at a single level in each of the varenicline and placebo control groups. Of the six successfully fused specimens, five from each group underwent successful biomechanical testing. The average stiffness at the fusion site of the varenicline group and control group was 49.2±17.5N/mm and 69.1±32.6N/mm, respectively (p=.271). The average peak load at the fusion site of the varenicline group and control group was 51.9±25.2N and 60.5±20.4N, respectively (p=.574). CONCLUSIONS Varenicline has no significant effect on the rate and quality of spinal fusions and remains an appropriate pharmaceutical adjunct for tobacco cessation in individuals undergoing spinal fusion.