Thoracolumbar Vertebrae Research Articles

Commentary: Thoracolumbar Vertebral Column Resection With Rectangular Endplate Cages Through a Posterior Approach: Surgical Techniques and Early Postoperative Outcomes.

Commentary: Thoracolumbar Vertebral Column Resection With Rectangular Endplate Cages Through a Posterior Approach: Surgical Techniques and Early Postoperative Outcomes.

Thoracolumbar Vertebral Column Resection With Rectangular Endplate Cages Through a Posterior Approach: Surgical Techniques and Early Postoperative Outcomes.

Thoracolumbar pathology can result in compression of neural elements, instability, and deformity. Circumferential decompression with anterior column reconstruction is often required to restore biomechanical stability and minimize the risk of implant failure. To assess the safety and viability of wide-footprint rectangular cages for vertebral column resection (VCR). We performed VCR with wide-footprint rectangular endplate cages, which were designed for transthoracic or retroperitoneal approaches. We present our technique using a single-stage posterior approach. A total of 45 patients underwent VCR with rectangular endplate cages. Mean age was 58 yr. Diagnoses included 23 tumors (51%), 14 infections (31%), and 8 deformities (18%). VCRs were performed in 10 upper thoracic, 17 middle thoracic, 14 lower thoracic, and 4 lumbar levels. Twenty-four cases involved a single level VCR (53%) with 18 two-level (40%) and 3 three-level (7%) VCRs. Average procedure duration was 264 min with mean estimated blood loss of 1900 ml. Neurological outcomes were stable in 27 cases (60%), improved in 16 (36%), and worse in 2 (4%). There were 7 medical and 7 surgical complications in 11 patients. There were significant decreases in postoperative thoracic kyphosis (47° vs 35°, P=.022) and regional kyphosis (34° vs 10°, P<.001). There were 2 cases of cage subsidence due to intraoperative endplate violation, neither of which progressed on CT scan at 14 and 35 mo. Posterior VCR with rectangular footprint cages is safe and feasible. This provides improved biomechanical stability without the morbidity of a lateral transthoracic or retroperitoneal approach.

Efficacy analysis of percutaneous pedicle screw fixation combined with percutaneous vertebroplasty in the treatment of osteoporotic vertebral compression fractures with kyphosis

BackgroundTo investigate the clinical effect of percutaneous pedicle screw fixation (PPSF) combined with percutaneous vertebroplasty (PVP) in the treatment of osteoporotic compression vertebral fracture (OVCF) of the thoracolumbar vertebra with kyphosis.MethodsOne hundred sixty-six patients before June 2017 were retrospectively analyzed, and patients were divided into PPSF + PVP group A and PVP group B. Operative time, bone mineral density, postoperative bed time, high compression ratio, bone cement leakage rate, and bone cement dose were recorded. Comparison of vertebral anterior edge height, Cobb angle, visual analogue score (VAS), and low back pain dysfunction index (ODI) between the two groups in preoperative, postoperative 3 days, postoperative 6 months, postoperative 12 months, and postoperative 24 months, postoperative complications were observed in the two groups.ResultsThe operation time of group A was longer than that of group B (59.0 ± 8.6 min, 26.6 ± 5.2 min), longer postoperative bed rest time (3.3 ± 0.7 days, 1.2 ± 0.5 days), the differences were statistically significant (P < 0.01), there was no difference in the amount of bone cement between the two groups (5.4 ± 0.6 ml, 5.3 ± 0.8 ml) (P > 0.05). The height of the anterior edge and Cobb angle of the two groups recovered significantly in postoperative 3 days. The height of anterior edge (2.7 ± 0.3 cm, 2.6 ± 0.2 cm, 2.5 ± 0.7 cm; 2.3 ± 0.6 cm, 1.7 ± 0.5 cm, 1.6 ± 0.3 cm) and Cobb angle (4.9 ± 2.2, 5.5 ± 2.3, 5.7 ± 2.3; 12.4 ± 3.2, 17.2 ± 2.5, 13.2 ± 2.3) was statistically significant in postoperative 6 months, postoperative 12 months, and postoperative 24 months (P < 0.01). VAS and ODI scores of postoperative 6 months and 12 months were significantly different between the two groups (P < 0.05). Postoperative complications in group B were much higher than those in group A.ConclusionThe efficacy of PVP alone was not satisfactory, and the rate of complications was high for OVCF patients with severe anterior edge compression with kyphosis. PPSF combined with PVP is recommended, the vertebral height loss was not obvious, the satisfaction was good, and the complication rate was lower during 2 years follow-up.

The prevalence and clinical significance of transitional vertebrae: a radiologic investigation using whole spine spiral three-dimensional computed tomographic images.

BackgroundErrors in counting spinal segments are common during interventional procedures when there are transitional vertebrae. In this study, we investigated the prevalence of the transitional vertebrae including thoracolumbar transitional vertebra (TLTV) and lumbosacral transitional vertebrae (LSTV). The relationship between the existence of TLTV and abnormal rib count or the existence of LSTV were also evaluated.MethodsThe vertebral levels were counted craniocaudally, starting from C1, based on the assumption of 7 cervical, 12 thoracic, and 5 lumbar vertebrae, using whole spine spiral three-dimensional computed tomographic images. The 20th and 25th vertebrae were defined as L1 and S1, respectively.ResultsIn total, 150 patients had TLTV, with a prevalence of 11.2% (150/1,340). LSTV was observed in 111 of 1,340 cases (8.3%). Sacralization was observed in 68 of 1,340 cases (5.1%) and lumbarization in 43 of 1,340 cases (3.2%). There was a significant relationship between the existence of TLTV and the abnormal rib count (odds ratio [OR]: 117.26, 95% confidence interval [95% CI]: 60.77–226.27; P < 0.001) and LSTV (OR: 7.38, 95% CI: 3.99–13.63; P < 0.001).ConclusionsOur study results suggest that patients with TLTV are more likely to have an abnormal rib count or LSTV. If a TLTV or LSTV is seen on the fluoroscopic image, a whole spine image is necessary to permit accurate numbering of the lumbar vertebra.

The phenotypic morphology of human lumbar plexus roots associated with changes in the thoracolumbar vertebral count and trade-off

This study investigated the developmental basis for the human phenotypic morphology of the interaction between the vertebrae and the nerve plexus by evaluating changes in the human lumbar plexus according to various thoracolumbar formulas. The dissection found that the changes in lumbar nerve roots reported by experimental embryology studies to be concomitant with thoracolumbar trade-off, i.e., a change in vertebrae from thoracic to lumbar with no change in the overall thoracolumbar count, were not apparent in humans with the usual 17 or mutant 16 thoracolumbar vertebrae. When vertebral changes in two segments were examined by comparing spines with a reduced thoracolumbar count of 16 to those with an increased count of 18, this tended to show only a single-segment caudal shift of the lumbar plexus. We cannot provide evidence for the phylogenetic difference in the concomitant changes of lumbar nerves and vertebrae, but comparisons between experimental rodents and humans highlighted fewer and shorter lumbar vertebra and more complicated lumbar plexus in humans. Therefore, these multiple differences may contribute to a human phenotypic morphology that is not evident in the concomitant transformation of vertebrae and lumbar nerves reported in experimental rodents.

A study on functional outcome of Thoraco lumbar vertebra fracture treated with posterolateral instrumental fusion

Background: The spinal injuries are common problems encountered by an orthoPaedician in day to day practice. The data on clinical outcome after instrumented spinal fusion is scant. Hence this study was undertaken to study the clinical outcome of the instrumented spinal fusion. Material and Methods: A prospective interventional study was undertaken among adult patients with acute thoracolumbar injuries admitted to the tertiary care hospital were included. Fifty adult patients with acute thoracolumbar injuries underwent the fusion with pedicle screws and rod instrumentation (Tango RS, Fa. Ulrich, Germany) with posterolateral fusion. The patients were followed up at 6th, 12th and 24th post-operative weeks. Results: The mean age was 40.1 years and more than three fourth were males. Fall from height was the major cause for the injury. The decrease in regional angle was statistically significant at 6th, 12th and 24th follow up visits when compared to baseline. The anterior wedge angle decreased to 5.240, 5.80 and 5.720 at 6th, 12th and 24th post-operative weeks respectively which was statistically significant when compared with the baseline. About 44%, 48% and 54% of the patients had normal sensory and motor functions at 6th, 12th and 24th weeks of follow up after surgery which was statistically significant when compared to the base line. Conclusion: This study was able to show that the postero lateral fusion had good clinical outcome.

Hypertrophic osteoarthropathy in a sheep

ABSTRACT: This research described the radiological, clinical and pathological aspects of hypertrophic osteoarthropathy in a seven-year-old Santa Inês ram. The main clinical features were lameness of the thoracic and pelvic limbs, rigid, cracking and enlarged of the humeroradial, humeroulnar and tibiofemoral joints, cervical spine stiffness, and severe lordosis of the thoracolumbar vertebrae. Dyspnea, nasal discharge and abdominal breathing were also observed. On radiographic examination of the thoracic and pelvic limbs, osteoarthrosis with the formation of osteophyte bridging, intra-articular calcification and periosteum reaction were observed. At necropsy were reported bilateral osteophytosis in the humeroradial, humeroulnar, tibiofemoral and interphalangeal joints, and fusion of the bodies of thoracic vertebrae T5-13 T6 and T12-T13. Microscopically, extensive areas of fibrosis were observed in the lungs and the affected joints were thickened by well demarcated and perpendicular orientated woven and trabecular bone proliferation in the epiphysis. The periosteum was also expanded by fibrous connective tissue that extended into and between the new proliferated bone. Based on these findings, hypertrophic osteoarthropathy, which is an unusual condition in sheep, was diagnosed.

The Relationship Between Transpedicular Stabilization with Spinal Canal Type.

To analyze the spinal canal type and spinal structure of patients, to determine appropriate preoperative preparation and surgical procedures to prevent material malposition, which is the most common complication of thoracolumbar posterior transpedicular stabilization (TPTS) and is a determiner of its clinical outcomes. A total of 214 cases were examined. TPTS procedures carried out on each thoracolumbar spine were evaluated. Twenty parameters were documented and retrospectively examined in each patient. Laminectomy is not helpful for healing unless there is spinal compression and ligamentotaxis is beneficial for healing. The correlation between the structure of the spinal canal and defective screw delivery found (p < 0.05). The spinal structure formed around the canal should be the first form to evaluate while TPTS applications to protect the spinal cord, which is the focal point of the spinal structure.

Management of thoracolumbar injury classification and severity score of 4 (TLICS=4) thoracolumbar vertebra fractures: Surgery versus conservative treatment.

This study aims to compare clinical and radiographic outcomes of surgical treatment and conservative treatment with bracing in neurologically intact patients with score 4 of TLICS thoracolumbar vertebra fractures. Patients with traumatic thoracolumbar junction fractures (T11-L2), the score of TLICS 4, and minimum 24-month follow-up were included in this study. Patients were divided into surgery and bracing groups. The groups were compared concerning clinical and demographical features, local kyphotic angles (LKA), vertebra height loss percentage (VHL), Oswestry Disability Index (ODI), Visual Analog Scale (VAS) and time to return to work. There were 74 patients (71 males, 3 females) in the surgery group and 76 patients (58 males, 18 females) in the bracing group. Although the surgery group showed better improvement in VAS scores within six months postoperatively, no significant difference was observed at the 24th-month evaluation (p<0.001 and p=0.270, respectively). ODI, LKA and VHL were significantly lower in the surgery group (p<0.001, p<0.001 and p<0.001, respectively). In addition, return to work was significantly earlier in the surgery group (p<0.001). The findings obtained in this study suggest that the surgical treatment for TLICS 4 patients with thoracolumbar fractures has better clinical and radiographic outcomes than the bracing. Moreover, returning time to the work of patients is shortened with surgical treatment. The surgical treatment seems to be the first and the appropriate choice in the management of TLICS 4 thoracolumbar vertebral fractures.

Clinical, diagnostic imaging, surgical findings and long-term outcome in a Cavalier King Charles Spaniel with thoracolumbar vertebral articular process hyperplasia

A 2-year-old female spayed Cavalier King Charles Spaniel presented with 10-day history of progressive painful T3–L3 myelopathy. MRI of the spine revealed an extradural dorsal spinal cord compression at the...

Sequestered Disc Herniation in a Dog

Background: Dogs are frequently affected by intervertebral disc degeneration, a structural failure associated with changes accelerated by aging. Disc degeneration may occur in the presence or absence of clinical signs, which are variable and common to other spinal cord diseases and therefore early diagnosis is crucial to a successful outcome. Treatment may be conservative or surgical according to severity of the clinical signs and should be combined with a rehabilitation protocol. Prognosis depends on the location of the spinal cord compression, volume and velocity of the disc material herniation and time between initial clinical signs, definitive diagnosis and therapeutic approach. Case: A nonchondrodystrophic 14-year-old dog with acute clinical manifestation of paraparesis and proprioceptive deficit in hind limbs was submitted to myelography examination. There was contrast column deviation in the T13-L1 region, determining spinal compression, and spondyloses were also noted in several thoracolumbar vertebrae. Hemilaminectomy was performed with complete removal of the compressor fragment. Histological analysis confirmed the presence of fibrocartilaginous material that corresponds to the part of the annulus fibrosus. The kidnap of the fragment was characterized by loss of continuity with the remaining disk. In these cases, magnetic resonance imaging does provides the definitive diagnosis, since neoplasm, arachnoid cysts and abscesses may be remaining differential diagnosis. Therefore, surgical approach followed by histopathological analysis of the obtained material are necessary to confirm the diagnosis.Discussion: The present report differs from most cases of disc herniation because it is a thoracolumbar lesion with an acute manifestation of significant neurological deficit in an elderly dog of non-chondrodystophic breed. Also, material of the free fibrous annulus itself in the medullary canal is not a common histopathological presentation of disc extrusion usually composed by nucleus pulposus. After neurolocalization of the lesion by clinical neurological examination, the radiographic evaluation shall precedes the myelography, since this is contraindicated when there is suspicion of discoespondylitis, fracture, dislocation or vertebral subluxation, which had not yet been discarded. Even if the MRI is performed, in the cases of a sequestered fragment, it still remais differential diagnoses include arachnoid cysts, discoespondylitis, hematomas, abscesses and neoplasms, including metastases, so only surgical approach to obtain material for histopathological analysis may provide definitive diagnosis. According to the histopathological examination, the herniated material had a fibrocartilaginous characteristic: several concentric fibrous blades, composed of collagen and fibrocartilage, thus characterizing the herniated material as a fragment of the fibrous ring. When removed from the vertebral canal, the contents did not show resistance, being withdrawn completely and without continuity with its origin intervertebral disc. The patient's disc herniation could not be classified as a disc protrusion because this affection is described as a projection of the fibrous annulus towards the vertebral canal due to the partial rupture of fibers and mineralization of the nucleus pulposus, without discontinuity of some content. Disc protrusion shows mild and progressive signs, except if there is complete rupture of the fibrous ring as can be seen in the sequestered disc herniation. Although infrequent, elderly animals of non-chondrodisiotic races may show acute signs of neurological deficits. Sequestrated disc herniation may mimic other lesions, requiring a surgical approach to obtain material for histopathological analysis to confirm the diagnosis.

2493 Large Perisplenic Hematoma and Spontaneous Hemoperitoneum as the Initial Presentation of Undiagnosed Burkitt's Lymphoma

INTRODUCTION: Spontaneous hemoperitoneum (SH) is a rare but life-threatening condition of non-traumatic etiology. It usually arises from spleen, hepatic, gynecologic and vascular sources. CASE DESCRIPTION/METHODS: A 61-year-old male with no known medical history presented with acute left sided, non-radiating abdominal pain. On examination, he was hemodynamically stable and had a soft, non-tender abdomen with splenomegaly. His laboratory workup was significant for pancytopenia. CT of abdomen showed a 9 cm perisplenic hematoma with moderate ascites. Patient was admitted to ICU for closer monitoring and a follow-up contrast enhanced CT of abdomen confirmed a perisplenic hematoma and revealed splenomegaly measuring 20 cm with the presence of hemoperitoneum. Sclerotic lesions in multiple thoracolumbar vertebrae, sacrum, and right iliac bone, suspicious for metastasis were also found. Follow-up chest CT revealed mildly enlarged mediastinal lymph nodes. His bone scan was negative. Further malignancy workup was remarkable for a low haptoglobin and high LDH levels. Flow cytometry was positive for CD4, CD5, CD10 and CD19 consistent with B cell lymphoma. Chromosomal analysis confirmed a translocation t(8;14) and FISH analysis showed fusion of MYC and IGH genes in 15.5% of cells, consistent with BL. The patient was managed conservatively. DISCUSSION: The exact mechanism of non-traumatic splenic hematoma leading to hemoperitoneum is unclear. One theory is an increased intra-splenic pressure due to endothelial hyperplasia and vascular occlusion due to a hypercoaguble state leading to spontaneous bleeding from leaking capillaries. Diagnosis is unsuspected and mainly made by CT as seen in our patient whose only findings included abdominal pain and pancytopenia. There have been very few reported cases in literature of SH and even fewer in patients with diagnosed BL. All such cases involved a ruptured spleen. Our patient is unique and to the best of our knowledge, the first ever reported case of SH presenting as an initial feature of a previously undiagnosed BL. Furthermore, his hemoperitoneum was secondary to a large perisplenic hematoma with an intact but enlarged spleen. Therefore, it is important for clinicians to keep lymphoma as a differential in patients presenting with acute abdominal pain and pancytopenia in order to effectively diagnose and treat an underlying malignancy and prevent future complications.

Surgical Treatment of Osteoporotic Vertebral Fracture Associated with Diffuse Idiopathic Skeletal Hyperostosis along with Comparative Assessment of the Levels of Affected Vertebra or Anterior Column Reconstruction.

Introduction Surgical treatment of osteoporotic vertebral fracture (OVF) often involves older patients with various comorbidities; thus, attending physicians must pay special attention to the invasiveness of surgical procedures and possible perioperative complications. In this retrospective observational study, we investigated the relationship between OVF and diffuse idiopathic skeletal hyperostosis (DISH) by examining the clinical characteristics and surgical outcomes. Methods Subjects comprised 26 patients (14 men, 12 women) who underwent surgical treatment for OVF complicated by DISH. Vertebral injuries affected the thoracolumbar transitional vertebrae in 18 patients and the middle and lower lumbar vertebrae in eight patients. The clinical characteristics, surgical results, radiological assessments, and outcomes were evaluated on the basis of the levels of affected vertebrae and whether anterior column reconstruction (ACR) was performed. Results Visual Analog Scale (VAS) measurements improved from an average of 69.7 mm before surgery to 21.3 mm after surgery. 14 patients had neurological deficits, who exhibited improvements by one or more steps on the Frankel scale after surgery. Activities of daily living (ADLs) were maintained during the six-month period following surgery in 23 patients. Comorbidity was observed in 22 patients. 14 patients had perioperative complications, and six required additional surgery. Both operating time and blood loss volume were significantly higher in patients in the middle and lower lumbar vertebrae and ACR groups. Postoperative correction loss was also significantly lower in the ACR group. Conclusions Favorable degrees of improvement in neurological deficits and VAS were observed following surgery in patients with OVF complicated by DISH, and postoperative ADLs were maintained in 92% of the patients. Elderly men frequently presented with comorbidities, and the frequencies of patients with perioperative complications and those requiring additional surgery were high.

Effect of loss of correction on functional outcomes in thoracolumbar burst fractures treated with short segment posterior instrumentation

Aim: Burst fractures are defined as vertebra fractures involving the anterior and middle columns and are associated with kyphotic deformity and retropulsion of bone fragment into the spinal canal. Although their treatment is controversial in the literature, use of transpedicular screws and short segment posterior instrumentation are increasingly common practices. The aim of this study is to investigate the radiological and functional outcomes of thoracolumbar vertebra burst fractures treated with short segment posterior instrumentation and to examine the effects of postoperative correction loss on these results.Methods: Patients who were surgically treated for thoracolumbar burst fractures and prospectively followed-up between 2000-2003 were scanned retrospectively for this cohort study. 48 patients were included in the study, of which 18 were females (37.5%) and 30 were males (62.5%). Denis Pain Scale (DPS) and Denis Work Scale (DWS) were used for functional analysis. Cobb angles that were measured preoperatively, on the first postoperative day, and at the last follow-up visit were used for evaluation of radiological outcomes. Spinal stenosis and remodelization rates were also calculated by computerized tomography obtained preoperatively and at the last follow-up. One-way ANOVA and Pearson correlation tests were used for statistical analysis.Results: No patient had any chronic pain complaints, and none were unable to work. The mean Cobb angles in the preoperative, early post-operative and final controls were measured as 23.2, 4.9, and 12.3 degrees, respectively. While preoperative mean Cobb angle and mean correction were positively correlated (r=0.85, P&lt;0.001), there was no correlation between preoperative mean Cobb angle and loss of correction (r=0.27, P=0.43). There was a correlation between correction and loss of correction (r=0.38, P=0.008). Spinal stenosis, which was 35.7% preoperatively, reduced to 17.1% in the last follow-up. The mean remodelization was 51.3%, which was significant (P&lt;0.001). Loss of correction was found significant in patients with poor DWS (P=0.003), and no such relationship was found in DPS. No correlation was found between the Cobb angle at the last follow-up, DPS and DWS. Conclusion: In conclusion, the loss of correction after short segment posterior instrumentation and fusion surgery is significantly higher in thoracolumbar burst fractures, especially when intraoperative correction exceeds 15 degrees. Denis Work Scale was significantly worse in patients with loss of correction above 10 degrees. The degree of loss of correction at the last follow-up is directly related to clinical and functional outcomes.

Missed manubriosternal dislocation in patient with thoracolumbar fracture, a case report

BackgroundSpine fractures combined with sternal injury are most commonly occur in the thoracic region. Lower cervical and thoracolumbar injuries have also been reported, especially for the patients with manubriosternal dislocation. The type of spine injury is easily recognized in initial presentation, but we may miss the sternal fracture and manubriosternal dislocation.Case presentationA 23-year-old male patient complained with chest, right ankle, and lumbar pain after a fall at ground level, with diagnosis of right distal tibial fracture, sternal fracture, calcaneus fracture, and L2 vertebral fracture. However, neurologically he was completely normal. He underwent the operation for his lower extremity and spine, but we missed his manubriosternal dislocation after discharged. After one month, he came to the clinic with complained of chest pain, the imaging exams showed anterior dislocation of manubriosternal joint. We chose conservative treatment for manubriosternal dislocation. He was followed up at monthly intervals and radiographs along with computerized tomography showed satisfactory in fracture healing of lumber and the sternal fracture. However, the manubriosternal dislocation was malunioned. The patient had appearance deformity of the manubriosternal joint.ConclusionThis case supports the concept of the existence and clinical relevance of the thoracic cage theory, the thoracolumbar vertebrae should also be included in the thoracic cage theory.

Comparison of whole body sagittal alignment during directed vs natural, relaxed standing postures in young, healthy adults

BACKGROUND CONTEXTImaging for adult spinal deformity is conventionally performed in a directed manner to assess the most upright standing posture one can assume. However, this method does not reflect an individual's natural, relaxed posture, which is the posture a patient likely reverts to postoperatively, and also the posture likely to explain spinal pathologies. PURPOSETo identify radiographic differences between directed and natural, relaxed standing postures in young healthy subjects. STUDY DESIGNA randomized, prospective, radiographic study. PATIENT SAMPLESixty healthy 21-year-old subjects (48 male, 12 female). OUTCOME MEASURESRadiographic parameters including sagittal vertical axis (SVA), C2 SVA, C2–7 SVA global cervical angle, T1-slope, global thoracic angle (GTA), thoracolumbar angle (TLA), global lumbar angle (GLA), sacral slope, pelvic tilt (PT), pelvic incidence, femoral alignment angle (FAA), and knee alignment angle (KAA). METHODSThe EOS whole body radiographs of patients in directed and natural, relaxed standing postures were obtained, with subsequent comparison of radiographic parameters. Differences in Roussouly curve types, sagittal curve apices, and end vertebrae were also evaluated. Univariate analyses using Wilcoxon sign-rank, paired t tests, and paired chi-square tests were performed. RESULTSCompared with directed standing, natural, relaxed standing results in a more kyphotic spinal profile marked by a significantly less lordotic GLA, larger GTA, TLA, and T1-slope. The PT+FAA demonstrated true hip movement during sagittal balancing. Lower thoracic and lumbar apices, lower thoracolumbar end vertebrae, and lower Roussouly curve types were observed during natural, relaxed standing. CONCLUSIONSOur study found significant differences in sagittal radiographic parameters between directed standing and the natural, relaxed standing posture, with the latter demonstrating a more kyphotic spinal profile in terms of magnitude and span, as well as complementary changes in cervical and spinopelvic alignment. The natural, relaxed standing posture, a marker for energy conservation principles in standing, may infer value in less aggressive lordotic restoration, as well as concentration of lordosis in the lower lumbar spine.

Increased variation in numbers of presacral vertebrae in suspensory mammals.

Restricted variation in numbers of presacral vertebrae in mammals is a classic example of evolutionary stasis. Cervical number is nearly invariable in most mammals, and numbers of thoracolumbar vertebrae are also highly conserved. A recent hypothesis posits that stasis in mammalian presacral count is due to stabilizing selection against the production of incomplete homeotic transformations at the lumbo-sacral border in fast-running mammals, while slower, ambulatory mammals more readily tolerate intermediate lumbar/sacral vertebrae. We test hypotheses of variation in presacral numbers of vertebrae based on running speed, positional behaviour and vertebral contribution to locomotion. We find support for the hypothesis that selection against changes in presacral vertebral number led to stasis in mammals that rely on dorsomobility of the spine during running and leaping, but our results are independent of running speed per se. Instead, we find that mammals adapted to dorsostability of the spine, such as those that engage in suspensory behaviour, demonstrate elevated variation in numbers of presacral vertebrae compared to dorsomobile mammals. We suggest that the evolution of dorsostability and reduced reliance on flexion and extension of the spine allowed for increased variation in numbers of presacral vertebrae, leading to departures from an otherwise stable evolutionary pattern.

Performance comparison of 159 Thoroughbred racehorses and matched cohorts before and after desmotomy of the interspinous ligament

Racehorses may perform poorly because of impinging dorsal spinous processes (DSPs) of the thoracolumbar vertebrae. No study has looked objectively at the long-term outcome of racehorses undergoing desmotomy of the interspinous ligament as a treatment for horses with poor performance caused by impinging DSPs. The aim of this study was to examine objectively, by using pre-operative and post-operative racing records, the effectiveness of desmotomy of the interspinous ligament (DISL) in improving the performance of racehorses with impinging DSPs. Medical records of all horses undergoing desmotomy of one or more interspinous ligaments at a referral equine hospital, between February 2015 and September 2016, were reviewed. The study was confined to Thoroughbred racehorses with sufficient historical information and racetrack data to allow their racing performances be compared to that of matched controls. Matched controls were of the same age, sex, and racing type and were trained at the same time by the same trainer as those undergoing desmotomy. The time to follow-up was at least 12 months.Of the 6545 horses presented for poor performance or lameness during the study period, 236 horses (3.6%) underwent desmotomy of one or more interspinous ligaments, and of these, 159 met the inclusion criteria. Horses undergoing desmotomy had significantly better improvement in racing performance than did matched controls. Eight horses developed unilateral neurogenic atrophy of epaxial musculature. DISL between impinging DSPs can improve the performance of racehorses experiencing from poor performance caused by pain resulting from the impinging processes.

Potential risk factors in development of the “halo sign” in patients performed transpedicular screw fixation through the posterior spinal approach.

It has been shown in literature that a fibrous tissue called "halo sign" in the radiological terminology can develop around the transpedicular screws implanted incompletely and/or incorrectly, which appears after movement of the screw in the cancellous bone. In this retrospective clinical study, 141 patients who underwent posterior spinal instrumentation for thoracic, lumbar or thoracolumbar vertebrae were evaluated using computed tomography (CT) and direct X-rays images for "halo sign" formation which refers in probable failure of spinal instrumentation. Hospital records included in the year 2014-2018 were examined and adult patients who were performed lumbar, thoracal, and thoracolumbar spinal instrumentation via posterior approach due to reasons such as "spine fracture", "spondylosis", "spondylolisthesis" and "intervertebral disc hernia" were included and evaluated in this study. The age and sex of the patients were recorded. Spinal X-ray and spinal CT images obtained during the postoperative follow-up period were examined. Halo sign was seen in 13 patients. Age (p=0.013), number of instrumented vertebrae (p=0.001) and number of transpedicular screws (p<0.001) values were different between the patients with halo sign and patients without halo sign. As a result, it was observed in this study that the formation of the halo sign in posterior spinal instrumentation system could develop in proportion to the number of transpedicular screw and patients' age. It was thought that the halo sign formation was not connected with the parameters called performed laminectomy, gender, inserted intervertebral cage, or vertebral region which were inserted transpedicular screws.

3D Computed Tomography Mapping of Thoracolumbar Vertebrae Fractures.

BackgroundFractures of the thoracolumbar (TL) spine represent 90% of all spinal fractures, followed by cervical and lumbar spine fractures. This study aimed to create fracture maps of the traumatic thoracolumbar (TL) fracture vertebral body (T12-L2) through the use of CT mapping as a big data visualization method to reveal recurrent patterns and characteristics of traumatic TL fractures.Material/MethodsA consecutive series of 174 fractured vertebrae (T12–L2) was used to create three-dimensional (3D) reconstruction images, which were superimposed and oriented to fit a model vertebral template by aligning specific bio-landmarks and reducing reconstructed fracture fragments. Fracture lines were found and traced to create a fracture map of the vertebral body.ResultsOur study consisted of 165 patients with an average age of 47 years. A total of 174 fractured vertebrae were collected, consisting of 59 T12 vertebral fractures, 60 L1 vertebral fractures, and 55 L2 vertebral fractures. Two-dimensional (2D) maps, 3D maps, and heat maps showed that the fracture lines tended to be concentrated in the upper third and anterior third of the vertebral body, as well as being distributed in annular wedges along the anterior and lateral sides of the vertebral body. When compared with T12, the distribution of fracture lines in L1 and especially in L2 was more scattered and disorganized.ConclusionsFracture maps revealed recurrent patterns and characteristics of the traumatic TL fracture vertebral body, which improves understanding of TL fractures, as well as helping to increase opportunities for follow-up research and aid clinical decision-making.