Vertebral Burst Fractures Research Articles

Osteoporotic burst fracture-clinical, radiological and functional outcome of three-column reconstruction using single posterior approach (Instrumentation, Corpectomy, Arthroscope Assisted Transpedicular Decompression and Mesh Cage)

PurposeTo evaluate a novel effective procedure utilizing three-column reconstruction via a posterior approach with a technique that utilizes an arthroscope to visualize the anterior surface of the dura during decompression. MethodsA Prospective Study. 80 Osteoporotic vertebral burst fracture patients with similar demographic data managed by three-column reconstruction through single posterior approach surgery: Pedicle screw fixation, Corpectomy, Arthroscope Assisted Transpedicular Decompression (AATD) and Fusion (Mesh Cage + Bone grafting). Preoperative and postoperative clinical parameters (Visual Analog Score VAS, swestry Disability Index ODI, neurlogy, radiological parameters and surgical variables were recorded analysed. ResultsNo significant differences in demographic data. Significant improvement was noted in VAS (pre-operative, 7.90 ±0.60; final follow-up 2.90 ± 0.54) and ODI (preoperative, 77.10 ± 6.96; final follow-up 21.30 ± 6.70). Neurological improvement was noted in 74 patients (Frankel grade E) while six patients remained non-ambulatory (Frankel grade C). Significant improvement was noted in local kyphosis angle (preoperative, 22.14 ± 2.60; postoperative, 10.40 ± 1.40) with a 10% loss of correction (2.5 ± 0.90) at final follow-up. Implant failure in two patients and proximal junctional failure in two patients managed with revision surgery. No iatrogenic dural or nerve injury. ConclusionsOsteoporotic Burst fracture can be managed with single posterior surgery, three-column reconstruction with mesh cage. It provides a significant improvement in clinical, radiological and functional outcomes. The arthroscope can improve a surgeon's operative field and magnification thereby ensuring complete decompression without injuring the dura or spinal cord.

Posttraumatic vertebral disc alterations after B and C type spinal injuries in childhood-Clinical and radiological 10-year results for two cases

Pediatric traumatic vertebral injuries usually present as stable A (AOspine classification) fractures, whereas B and C injuries are relatively uncommon. In contrast to adults the appropriate treatment strategy in children remains an issue of debate.The data from two pediatric patients admitted with B and C type spinal injuries in 2007 and 2008 were retrospectively analyzed. The initial diagnostics were performed via computed tomography (CT) and an additional magnetic resonance imaging (MRI) was carried out in one case.The clinical and radiological follow-up controls were carried out after 77 and 66 months as well as 123 and 112 months, respectively. In both cases thoracolumbar MRI scans revealed degenerative alterations of the ventral half of the L1/L2 disc with aregular disc signal in the dorsal segment at the first follow-up and aprogressive disc degeneration in one patient at the second follow-up.Surgical treatment of pediatric B and C type injuries via open reduction and temporary monosegmental posterior screw and rod instrumentation results in satisfactory clinical and radiological outcomes. In the absence of vertebral burst fractures, the function and stability of discoligamentous injuries in children can be restored without any additional osseous fusion.

Outcome of Thoracic Vertebral Burst Fractures by Ligamentotaxis and Fixation

Ligamentotaxis is a known method in the management of spinal burst fractures but the indications and efficacy are controversial. In the present study we evaluated the outcome of ligamentotaxis without fusion. Thirty five patients with single-level thoracic burst fractures with intact PLL were selected for treatment with this method. The analysis of the outcome was with the help of frankel neurological grading system, radiographic measurements, and Visual analog scale and Oswestry disability index was used to evaluate the pain and functional outcome. The average follow-up period was 28.5 months. There was a statistically significant correction of anterior vertebral height from 53.9% to 96.2% postoperatively; and that of the posterior vertebral height increased from 86.6% to 98.1% postoperatively. Preoperative canal compromise which averaged to 34.96% improved to 5.52% at latest follow up. Neurological status was improved in all patients except one patient with frankel grade A. The ODI and VAS score improved significantly in all patients. Among the broad spectrum of treatment options for thoracic burst fractures ligamentotaxis with screw fixation falls in mid range of the spectrum, providing less aggressive surgery and beneficial clinical and technical outcome. Keywords: Thoracic, burst fracture, ligamentotaxis, indirect reduction, instrumentation

Single-Stage Transpedicular Approach for Circumferential Arthrodesis in Traumatic Lumbar Vertebral Body Burst Fractures

Abstract Background Traumatic vertebral burst fractures can be surgically approached via different approaches (anterior/posterior, or combined). Posterior transpedicular approach (PTA) is a posterior approach that has the advantage of achieving circumferential arthrodesis via single posterior-only approach. The purpose of this study was to analyze our experience with PTA in management of traumatic lumbar burst fractures (TLBFs). Methods All consecutive patients with TLBFs managed with PTA over 3 years’ duration were included in this retrospective study. Correction of kyphotic deformity and change in neurologic status were analyzed to assess outcome. Cobb’s angle and American Spinal Injury Association (ASIA) grade were used for this purpose. Results There were 12 males and 8 females. Five patients had complete (ASIA-A) while 12 had incomplete injury. The mean preoperative Cobb’s angle was 14.23 degrees that improved to–3.21 degrees postoperatively (mean kyphosis correction: 17.44 degrees). None of the patients developed iatrogenic nerve root injury. There was no perioperative mortality. The mean Cobb’s angle was 1.45 degrees at 36 months’ follow-up. Four patients developed cage subsidence but none required revision surgery. Postoperatively, 13 (65%) patients showed neurologic improvement and none deteriorated. The average ASIA score improved from 2.82 to 4.23. A fusion rate of 96% was observed at last follow-up. Conclusion The advantages of PTA including sense of familiarity with posterior approach among spine surgeons, lesser approach-related morbidity, and results comparable to anterior/combined approaches, make the PTA an attractive option for managing TLBFs. Although technically difficult, it can be successfully used for circumferential arthrodesis in the lumbar region without sacrificing nerve roots.

Surgical Intervention for Osteoporotic Vertebral Burst Fractures in Middle-low Lumbar Spine with Special Reference to Postoperative Complications Affecting Surgical Outcomes.

The purpose of this study was to investigate the clinical and radiological features of osteoporotic burst fractures affecting levels below the second lumbar (middle-low lumbar) vertebrae, and to clarify the appropriate surgical procedure to avoid postoperative complications. Thirty-eight consecutive patients (nine male, 29 female; mean age: 74.8 years; range: 60–86 years) with burst fractures affecting the middle-low lumbar vertebrae who underwent posterior-instrumented fusion were included. Using the Magerl classification system, these fractures were classified into three types: 16 patients with superior incomplete burst fracture (superior-type), 11 patients with inferior incomplete burst fracture (inferior-type) and 11 patients with complete burst fracture (complete-type). The clinical features were investigated for each type, and postoperative complications such as postoperative vertebral collapse (PVC) and instrumentation failure were assessed after a mean follow-up period of 3.1 years (range: 1–8.1 years). All patients suffered from severe leg pain by radiculopathy, except one with superior-type fracture who exhibited cauda equina syndrome. Nineteen of 27 patients with superior- or inferior-type fracture were found to have spondylolisthesis due to segmental instability. Although postoperative neurological status improved significantly, lumbar lordosis and segmental lordosis at the fused level deteriorated from the postoperative period to the final follow-up due to postoperative complications caused mainly by PVC (29%) and instrument failure (37%). Posterior-instrumented fusion led to a good clinical outcome; however, a higher incidence of postoperative complications due to bone fragility was inevitable. Therefore, short-segment instrument and fusion with some augumentation techniqus, together with strong osteoporotic medications may be required to avoid such complications.

A novel unidirectional porous β-tricalcium phosphate grafting for vertebral fracture in the elderly: preliminary case series.

Objective: To treat vertebral fractures with posterior wall injury in the elderly, vertebral bone grafting is generally performed through a posterior transpedicular approach, combined with pedicle screw fixation. An autologous bone is ideal to treat this disorder. However, harvesting autologous bones from the elderly with osteoporosis is limited by the amount and quality of available autologous bone. Thus, we developed a bone-grafting substitute. The newly developed unidirectional porous β-tricalcium phosphate, with a porosity of 57% (UDPTCP; Affinos®, Kuraray Co., Ltd., Tokyo, Japan), is used in the bone-grafting procedure. This is the first report of UDPTCP used as an artificial bone graft in patients with an acute vertebral burst fracture.Materials and Methods: UDPTCP (mean: 4.2 g) was implanted through the pedicle, and posterior instrumentation was achieved with pedicle screws in five elderly patients. Resorption of UDPTCP and substitution with the autologous bone were evaluated on computed tomography (CT) and plain X-ray performed immediately and at 3, 6, and 12 months after the operation.Results: In case 1, the pedicle screws did not loosen, and UDPTCP was completely resorbed and replaced with the autologous bone at 3 postoperative months. In the other four cases, although the pedicle screws or the caudal part loosened because of osteoporosis, resorption of UDPTCP was observed at 3 postoperative months. At 6 postoperative months, progressive substitution with the autologous bone was confirmed, and at 12 postoperative months, formation of the good autologous bone was confirmed.Conclusion: This preliminary case series demonstrated that the newly developed UDPTCP shows good clinical potential as a bone-graft substitute for acute vertebral burst fractures in the elderly, including patients with osteoporosis.

T7 vertebral burst fracture with left pedicle separated from vertebral body and displaced in vertebral canal without neurologic deficits in a 12 years old motorbike competition rider

T7 vertebral burst fracture with left pedicle separated from vertebral body and displaced in vertebral canal without neurologic deficits in a 12 years old motorbike competition rider

Expression of Matrix Metalloproteinases, Tissue Inhibitors of Metalloproteinases, and Interleukins in Vertebral Cartilage Endplate.

Turnover of cartilage endplate extracellular matrix (ECM) may play an important role in disc degeneration and low back pain (LBP). However, the expression pattern of pro-inflammatory factors, matrix metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) in the cartilage endplates (CEP) of intervertebral discs (IVD) is not understood. We aimed to examine the transcriptional levels of MMP, TIMP, and interleukins (IL), and the correlations between them. Thirty degenerated cartilage endplate samples from patients with LBP who underwent lumbar fusion surgery were included in the degenerated group. Ten patients without LBP history who underwent lumbar surgery because of vertebral burst fractures were included in the control group. The degenerative severity of the samples was evaluated by MRI, and hematoxylin-eosin and safranin O-fast green (SO-FG) staining. Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA levels of MMP-1, MMP-3, MMP-9, MMP-13, TIMP-1, TIMP-2, TIMP-3, IL-1α, IL-1β, and IL-6. The correlations between the levels of these genes were tested using Spearman's rho test. Hematoxylin-eosin and SO-FG staining confirmed a decrease in cell number and proteoglycans in the degenerated cartilage endplate. MRI showed significant signal changes in degenerated cartilage endplates. Patients in the degenerated group showed a higher rate of endplate Modic changes when compared with the control group. MMP-3, MMP-9, TIMP-3, IL-1α, and IL-1β were elevated with statistical significance, while MMP-1, MMP-13, TIMP-1, TIMP-2, and IL-6 were changed without statistical significance or remained unchanged. Expression of MMP-3 was positively correlated with IL-1α (Spearman coefficient, 0.486; P < 0.05); expression of TIMP-3 was positively correlated with MMP-9, IL-1α, and IL-1β (Spearman coefficient, 0.577, 0.407, and 0.571, respectively; P < 0.05). MMP-3, MMP-9, TIMP-3, IL-1α, and IL-1β may play a role in the process of cartilage endplate degeneration. MMP-3 may be regulated by IL-1α, and TIMP-3 might be associated with MMP-9 and regulated by IL-1α and IL-1β.

Three-dimensional thoracoscopic vertebral body replacement at the thoracolumbar junction.

The aim is to stabilize the thoracolumbar spine with athoracoscopically implanted vertebral body replacement (VBR). To improve intraoperative depth perception and orientation, implantation is performed under three-dimensional (3D) thoracoscopic vision. Vertebral burst fractures at the thoracolumbar junction (A4AOSpine classification), pseudarthrosis, and posttraumatic instability with increasing kyphosis. Severe pulmonary dysfunctions, pulmonary or thoracic infections, previous thoracic surgery, and pulmonary adhesions. The patient is lying in aright lateral decubitus position. Localization of the fractured vertebra. Minimally invasive transthoracic approach. Perform single lung ventilation and insert the 3D thoracoscope two intercostal spaces above the working portal. Utilization of special binocular glasses for 3D vision of the operation field and secure resection of the fractured vertebra. Measurement of the bony defect and insertion of the expandable cage. Control of correct cage position under fluoroscopy. Insertion of achest tube and inflate the left lung. Chest × ray Remove chest tube when output is <500 ml/24 h Early mobilization on the ward 6weeks no weight-bearing >5 kg RESULTS: Between 2012 and 2017, 12patients received aVBR under 3D thoracoscopic vision. After amean follow up of 26months, no cage dislocation was noticed and all patients recovered from the initial back pain. Complications were notable in two cases (17%) with asmall pneumothorax after removal of the chest tube and postoperative pneumonia in one patient (8%). All responded to conservative treatment. Revision surgery was not necessary.

Burst fractures of the thoracolumbar spine (Part II): literature review

Current approach to the diagnosis, classification and prediction of the course of burst fractures of the thoracolumbar spine takes into account primarily the morphology and mechanical origin of the damage. The timing of surgical care depends on the general condition of the patient and his neurological status. It is also very important to take into account the history of the disease, namely whether movements were stored in the limbs right after the injury. In our opinion, this is a very important sign of the further course of the disease. Given a large range of classifications in our work we focus on the classification of F. Magler, and we use Denis F. classification in the McCormack T. version when choosing tactics for surgical intervention. The existing surgical classification is quite perfect, but it does not take into account the presence of neurological symptoms, but only the possibility of kyphotic deformation, without considering the possible rotational displacements. The gaining new knowledge in the field of biomechanics and morphology of burst vertebral fractures will improve the diagnosis and classification of damages.

Burst fractures of the thoracolumbar spine (Part I): literature review

Current approach to the diagnosis, classification and prediction of the course of burst fractures of the thoracolumbar spine takes into account primarily the morphology and mechanical origin of the damage. The timing of surgical care depends on the general condition of the patient and his neurological status. It is also very important to take into account the history of the disease, namely whether movements were stored in the limbs right after the injury. In our opinion, this is a very important sign of the further course of the disease. Given a large range of classifications in our work we focus on the classification of F. Magler, and we use Denis F. classification in the McCormack T. version when choosing tactics for surgical intervention. The existing surgical classification is quite perfect, but it does not take into account the presence of neurological symptoms, but only the possibility of kyphotic deformation, without considering the possible rotational displacements. The gaining new knowledge in the field of biomechanics and morphology of burst vertebral fractures will improve the diagnosis and classification of damages.

Operative management of unstable thoracolumbar burst fractures.

Operative management of unstable burst vertebral fractures is challenging and debatable. This study of such cases was conducted at the Aga Khan Hospital, Karachi from January 1998 to April 2003. All surgically managed spine injuries were reviewed from case notes and operative records. Clinical outcome was assessed by Hanover spine score and correction of kyphosis was measured for radiological assessment. The results were analyzed by Wilcoxon sign rank test for two related samples and p-value < 0.05 was considered significant. Ten patients were identified by inclusion criteria. There was statistically significant difference between mean pre-and postoperative Hanover spine score (p=0.008). Likewise, there was significant difference between mean immediate postoperative and final follow-up kyphosis. (p=0.006). Critical assessment of neurologic and structural extent of injury, proper pre-operative planning and surgical expertise can optimize the outcome of patients.

The NLRP3/Caspase-1/Interleukin-1β Axis Is Active in Human Lumbar Cartilaginous Endplate Degeneration.

Modic changes are the MRI signal changes of degenerative lumbar vertebral endplate and which lead to or accelerate intervertebral disc degeneration. NLRP3, caspase-1, and interleukin-1β (IL-1β) play a pivotal role in the pathogenesis of many inflammatory diseases, such as osteoarthritis. However, the roles of IL-1β and its activators caspase-1 and NLRP3 are unclear in the degenerative endplate. We asked: (1) What are the degenerative changes of the histologic features and chondrogenic markers' gene expressions between the cartilaginous endplates of patients with Modic changes and trauma (control)? (2) How does the NLRP3/caspase-1/IL-1β axis in the cartilaginous endplates of patients with Modic changes compare with control (trauma) specimens? Surgical specimens of cartilaginous endplates were divided into Modic changes (n = 56) and the trauma control (n = 16) groups. Hematoxylin and eosin and safranin O staining of cartilaginous endplate tissues were done to evaluate the extracellular matrix. Reverse transcription-polymerase chain reaction was performed on these tissues to investigate mRNA expression of type II collagen (Col II), SOX-9, matrix metalloproteinase-3, and a disintegrin like and metalloproteinase thrombospondin type I motifs-5. NLRP3, caspase-1, and IL-1β were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry. Hematoxylin and eosin and safranin O staining showed the extracellular matrix degraded in the cartilaginous endplates of patients with Modic changes but not in the control cartilaginous endplates. Chondrogenic Col II (p = 0.024) and SOX9 (p = 0.053) were downregulated in the Modic changes group compared with the control group. In contrast to the control group, the transcriptional levels of NLRP3 (p < 0.001), caspase-1 (p = 0.054), and IL-1β (p = 0.001) were all upregulated in the Modic changes group. The expression of NLRP3, caspase-1, and IL-1β was upregulated in the patients with low back pain and Modic changes on MRI compared with patients with vertebral burst fracture without degenerative changes on MRI. The data suggest the NLRP3/caspase-1/IL-1β axis may be implicated in lumbar cartilaginous endplate degeneration. The NLRP3/caspase-1/IL-1β axis is active in cartilaginous endplates of patients with Modic changes and inflammatory cascades can exacerbate the cartilaginous endplate degeneration which may act as a trigger for intervertebral disc degeneration and low back pain. If these findings can be confirmed by others, we hope that new and effective therapy could be developed directed against this target.

Ceramic cement as a potential stand-alone treatment for bone fractures: An in vitro study of ceramic–bone composites

BackgroundA vertebral burst fracture (VBF) treated with vertebroplasty using a ceramic cement consists of four regions; native bone fragments, native ceramic cement, ceramic cement–trabecular bone (ceramic–bone) composite and ceramic–bone interface. Although the mechanical properties of native bone and native ceramic cements have been well investigated, the mechanical properties of ceramic–bone composite and ceramic–bone interface remain unknown. Therefore, the aim of this study was to determine the mechanical properties of ceramic–bone composites and ceramic–bone interfaces. Two types of ceramic cement, calcium aluminate (CAC) with (w/F) and without (wo/F) fiber reinforcement, were investigated. MethodsCeramic–bone composite (Full, wo/F and w/F) and ceramic–bone interface (Fract, wo/F and w/F) groups were tested to determine their compressive and tensile properties. While a continuous bone cylinder was used for samples in the Full groups, each bone cylinder for the samples in the Fract groups contained a 3mm geometrical discontinuity to mimic the fracture gaps in VBFs. Two Cement groups (wo/F and w/F) and a Bone group were included in the study as controls. Micro-CT images were used to determine the bone morphological parameters, as potential predictors of the mechanical properties of Full and Fract groups. ResultsThe compressive strengths of Full and Fract groups were substantially lower than native CAC, but higher than bone. The tensile strength of the Full group was equal to bone, while the tensile strength of the Fract group was equivalent to CAC. Variable relationships between the bone morphological parameters and mechanical properties of Full and Fract groups were observed. Fiber reinforcement at an injectable level had a minimal influence on the mechanical properties. ConclusionsCAC augmentation does not provide adequate stabilization of bone fragments. The interface between bone and cement represents a weak point. The effect of cement augmentation cannot be predicted by bone morphological properties.

In silico investigation of vertebroplasty as a stand-alone treatment for vertebral burst fractures

BackgroundThe use of percutaneous vertebroplasty as a stand-alone treatment for stable vertebral burst fractures has been investigated in vitro and in clinical studies. These studies present inconsistent results on the mechanical response of vertebroplasty-treated burst fractures. In addition, observations of the loss of sagittal alignment after vertebroplasty raise questions on the applicability of vertebroplasty for burst fractures. Therefore, the aim of this study was to investigate the mechanical stability of burst fractures after stand-alone treatment by vertebroplasty. MethodsFinite element simulations were performed with models generated from two laboratory-induced burst fractures in human thoracolumbar specimens. The burst fracture models were virtually injected with various cement volumes using a unipedicular or bipedicular approach. The models were subjected to four individual loads (compression, lateral bending, extension and torsion) and a multi-axial load case in the physiological range. FindingsAll treated burst fractures showed improvements in stiffness and a reduction in inter-fragmentary displacements, thus potentially providing a suitable mechanical environment for fracture healing. However, large volumes of the trabecular bone (<43%), cement (<53%) and bone–cement composite (<58%) were predicted to experience strain levels exceeding the yield point. While damage was not specifically modeled, this implies a potential collapse of the treated vertebra due to local failure. InterpretationTo improve the primary stability and to prevent the collapse of treated burst fractures, the use of posterior instrumentation is suggested as an adjunct to vertebroplasty.

Early mobilisation of thoracolumbar burst fractures without neurology: a natural history observation.

The authors present the results of a cohort study of 60 adult patients presenting sequentially over a period of 15 years from 1997 to 2012 to our hospital for treatment of thoracic and/or lumbar vertebral burst fractures, but without neurological deficit. All patients were treated by early mobilisation within the limits of pain, early bracing for patient confidence and all progress in mobilisation was recorded on video. Initial hospital stay was one week. Subsequent reviews were made on an outpatient basis. The mean duration from admission to final follow-up was three months, and longer follow-up was undertaken telephonically. The mean kyphosis deformity on arrival was 17.4° (5° to 29°); mean kyphosis at final discharge three months later was 19.5° (1° to 28°). Spinal canal encroachment had no influence on successful functional recovery. Pain has not been a significant problem for any patient, irrespective of the degree of kyphosis and no patient has a self-perception of clinical deformity. In all, 11 patients took occasional analgesia. All patients returned to their original work level or better. Two patients died 2.5 years after treatment, from unrelated causes. The natural history of thoracolumbar burst fractures without neurology would appear to be benign.

Impact of Disc-Endplate Injury on Loss of Reduction of Thoracolumbar Vertebral Burst Fracture

Impact of Disc-Endplate Injury on Loss of Reduction of Thoracolumbar Vertebral Burst Fracture

A Biomechanical Assessment of Kyphoplasty as a Stand-Alone Treatment in a Human Cadaveric Burst Fracture Model

In vitro biomechanics study. To determine whether kyphoplasty is an adequate stand-alone treatment for restoring biomechanical stability in the spine after experiencing high-energy vertebral burst fractures. Kyphoplasty in the treatment of high-energy vertebral burst fractures has been shown by previous studies to significantly improve stiffness when used in conjunction with pedicle screw instrumentation. However, it is not known whether kyphoplasty as a stand-alone treatment may be an acceptable method for restoring biomechanical stability of a spinal motion segment post-burst fracture while allowing flexibility of the motion segment through the intervertebral discs. Young cadaveric spines (15-50 yr old; 3 males and 1 female; bone mineral density 0.27-0.31 gHA/cm) were divided into motion segments consisting of 3 intact vertebrae separated by 2 intervertebral discs (T11-L1 and L2-L4). Mechanical testing in axial, flexion/extension, lateral bending, and torsion was performed on each specimen in an intact state, after an experimentally simulated burst fracture and postkyphoplasty. Computed tomography was used to confirm the burst fractures and quantify cement placement. Between the intact and burst-fractured states significant decreases in stiffness were seen in all loading modes (63%-69%). Burst fracture increased the average angulation of the vertebral endplates 147% and decreased vertebral body height by an average of 40%. Postkyphoplasty, only small recoveries in stiffness were seen in axial, flexion/extension, and lateral bending (4%-12%), with no improvement in torsional stiffness. Large angular deformations (85%) and height loss (31%) remained postkyphoplasty as compared with the intact state. Lack of overall improvement in biomechanical stiffness indicates failure of kyphoplasty to sufficiently restore stability as a stand-alone treatment after high-energy burst fracture. The lack of stability can be explained by an inability to biomechanically repair the compromised intervertebral discs. 3.

Indian hedgehog contributes to human cartilage endplate degeneration

To determine the role of Indian hedgehog (Ihh) signaling in human cartilage endplate (CEP) degeneration. CEP-degenerated tissues from patients with Modic I or II changes (n = 9 and 45, respectively) and normal tissues from vertebral burst fracture patients (n = 17) were collected. Specimens were either cut into slices for organ culture ex vivo or digested to isolate chondrocytes for cell culture in vitro. Ihh expression and the effect of Ihh on cartilage degeneration were determined by investigating degeneration markers in this study. Ihh expression and cartilage degeneration markers significantly increased in the Modic I and II groups. The expression of cartilage degeneration markers was positively correlated with degeneration severity. Gain-of-function for Ihh promoted expression of cartilage degeneration markers in vitro, while loss-of-function for Ihh inhibited their expression both in vitro and ex vivo. These findings demonstrated that Ihh promotes CEP degeneration. Blocking Ihh pathway has potential clinical usage for attenuating CEP degeneration.

Minimally Invasive Transpsoas L2 Corpectomy and Percutaneous Pedicle Screw Fixation for Osteoporotic Burst Fracture in the Elderly

Osteoporotic vertebral burst fractures are an increasingly common cause of pain and severe functional disability in the elderly. Although anterior-posterior surgical stabilization offers an efficacious and durable treatment, the associated high blood loss, long durations of surgery, and prolonged hospitalization are often not tolerable for elderly patients, who are most often medically frail with multiple comorbidities. We report a case of an L2 osteoporotic burst fracture in an elderly patient with significant comorbidities treated with a minimally invasive tubular direct lateral transpsoas approach for L2 vertebrectomy and anterior cage placement. The construct was supplemented by a percutaneous pedicle screw construct and adjacent level vertebroplasty. Duration of surgery was 3.5 hours with a total of 35 mL blood loss. The patient was discharged ambulating 36 hours after surgery and reported marked improvement in pain, disability, and quality of life measures at 6 weeks postoperatively. L2 vertebrectomy by direct lateral transpsoas tube systems supplemented by percutaneous pedicle screws can be performed safely and may allow for anterior column decompression and reconstruction in elderly or comorbid patients not otherwise able to tolerate traditional stabilization procedures.