Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm.

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

The effect of scoliosis surgery on pulmonary function in spinal muscular atrophy patients: review of the literature and a meta-analysis.

PURPOSE: To determine the effect of surgical instrumentation on pulmonary function after surgery. METHODS: A literature review was performed to identify articles reporting on the effect of scoliosis surgery on the pulmonary function in patients with spinal muscular atrophy (SMA). Data for each patient were extracted from included studies, and a meta-analysis was performed using the values of forced vital capacity (FVC) before and after surgery. RESULTS: A total of 127 articles were reviewed, and ten articles were selected for data extraction according to inclusion criteria. The results of the meta-analysis showed no difference in respiratory function pre-operatively and at last follow-up. Four out of ten studies demonstrated similar results and five studies reported a decrease in pulmonary function after surgery. Only one study showed improvement in lung function. CONCLUSION: At the moment, there is insufficient evidence in the literature to support that spinal surgery can improve respiratory function. According to our meta-analysis study, vital capacity remains either unchanged or the rate of deterioration is decreased after surgery. Nevertheless, these are both considered favorable outcomes taking into account the natural course of the disease with progressive deterioration of pulmonary function over time.

Diabetes mellitus as a risk factor for intervertebral disc degeneration: a critical review.

PURPOSE: To examine to what extent diabetes mellitus (DM) is implicated as a distinct mechanism in intervertebral disc degeneration (IVDD). METHODS: The published clinical and laboratory data relevant to this matter are critically reviewed. A total of 12 clinical studies evaluate the association between DM and degenerative changes such as IVDD, spinal stenosis (SS) and IVD herniation. A total of 34 laboratory research papers evaluate the association between DM and IVDD. RESULTS: There are 7 studies that correlate DM with IVDD, 4 of them showing that DM is a significant risk factor for degeneration, and 3 of them failing to establish any association. Three studies demonstrate significant association between DM and SS. However, 2 of these studies also include patients with IVD herniation that failed to demonstrate any correlation with DM. Two other studies indicate a significant association between DM and lumbar disc herniation. Multiple different mechanisms, acting independently or interactively, cause tissue damage leading to IVDD including: microangiopathy of the subchondral vertebral endplate, cellular senescence, cell death (through apoptosis or autophagy), hyperglycaemia, advance glycation end products, adipokines, and cytokines (through oxidative, osmotic, and inflammatory mechanisms). CONCLUSION: The clinical evidence is not consistent, but weakly supports the relationship between DM and IVDD. However, the laboratory studies consistently suggest that DM interferes with multipronged aberrant molecular and biochemical pathways that provoke IVDD. Taken as a whole, the strong laboratory evidence and the weak clinical studies implicate DM as a distinct contributing factor for IVDD. These slides can be retrieved under Electronic Supplementary Material.

The effectiveness of biodegradable instrumentation in the treatment of spinal fractures.

INTRODUCTION: A variety of biodegradable implants (screws, rods, plates and cages) are available which are composed of many different biodegradable polymers with varying characteristics. The present review of animal and clinical studies examines the efficacy and safety of biodegradable implants in spinal fracture intervention. METHODS: A review of the literature through March 2018 was performed using PubMed and Cochrane databases. Success rates were calculated according to sufficient tissue biocompatibility, solid clinical fusion and propensity for osseointegration. RESULTS: 49 articles (24 animal and 25 human studies) were included. In animal experiments, the overall success rate for spinal fusion was 60.3%, while the mean success rate regarding the cervical spine was 51.8% compared to 68.1% for the lumbar spine (p = 0.002). In studies involving control group(s): the mean bioabsorbable implant success rate for spinal fusion was 42% compared to 57% for conventional implants (p = 0.0016). In the lumbar spine pL-lactide acid (PLLA) had 75.2% success rate compared to poly (L-lactide-co-DL-lactide) (PLDLLA) at 53.4% (p = 0.003). In clinical studies, the overall mean success rate was 89%, while the mean success rate regarding the cervical spine was 92%, as compared to 83.6% for the lumbar spine (p = 0.001). In studies involving control group(s): the mean bioabsorbable implant success rate was 75% compared to a conventional implant mean success rate of 97% (p<0.0001). In the cervical spine PLLA had a 98.7% success rate compared to 90% with PLDLLA (p = 0.015). In the lumbar spine PLDLLA had 84.7% success rate compared to 63.6% for poly-glycolic acid (PGA) (p = 0.085). DISCUSSION: Studies combined biodegradable and conventional implants. Polymers were used in various combinations and surface modification of the implants also varied. Comparison studies were of small sample size. Animal and clinical studies diverged. The current data are not encouraging. The end-point of assessing osseointegration varies in the studies and is indeterminate. In early stages the structure comparison of osseous restoration using biodegradable implants appears inferior to utilization of conventional cages and instrumentation. There is no statistically significant evidence supporting the efficacy of biodegradable implants replacing traditional instrumentation. There is a lack of prospective clinical trials with long-term follow-up regarding utilization of biodegradable implants and the available data does not support their routine use in spinal fracture intervention.

Surgical options for osteoporotic vertebral compression fractures complicated with spinal deformity and neurologic deficit.

INTRODUCTION: This paper describes surgical options for Osteoporotic vertebral compression fracture (OVCF) with acute flexible or chronic rigid kyphosis, and pseudarthrosis complicated with pain and neurologic deficit. METHODS: This study has two components. a) A prospective clinical study of surgical treatment of 31 patients (age: 69±11 years) with either acute flexible or progressive pseudarthrotic kyphosis manifested with severe pain or neurological deficit between 2010 and 2014. Eleven patients exhibited neurocompression (Frankel B, C, D). Surgery consisted in indirect reduction, kyphoplasty, and short posterior instrumentation in 28 patients and multilevel instrumentation in three. b) The second component involved a literature search of OVCF complicated with acute or painful chronic deformities and neurologic deficit, managed with open surgical approach. RESULTS: Indirect reduction, kyphoplasty and short posterior stabilization can restore satisfactory anatomic alignment and neurological deficit. Multilevel instrumentation was used for rigid long kyphosis. Complications were related to a) screw pull out and junctional kyphosis (4 patients) one of the patients also developed anterior migration of cement, b) cement leakage (4 patients). L5 radiculopathy occurred in one patient. The others remained asymptomatic. The literature review concluded that corpectomy with anterior, posterior or combined instrumentations is indicated for burst fractures, or rigid kyphosis with neurocompression. Prompt decompression with anatomical alignment may restore paraplegia. Complications were germane to osteoporotic bone predisposing to hardware loosening or cut out and dislodgement of instrumentation. DISCUSSION: Neurologic deficit associated with fractures or progressive pseudarthrotic kyphosis effectively may respond to indirect postural reduction, kyphoplasty and posterior percutaneous short segment transpedicle instrumentation. For burst fractures and rigid chronic kyphosis corpectomy reconstructed with cages and anterior, or posterior or combined instrumentations can restore and maintain normal anatomy. The following guidelines for optimal surgical instrumentation have been established: To prevent screw loosening and junctional kyphosis the instrumentation should not end within the kyphotic segment. Screws for anterior instrumentation should penetrate the contralateral cortex. Multiple site of fixation or combined anterior and posterior instrumentations dissipate stresses at any one site. Augmentation of transpedicle screw fixation with cement is a sound technical principle. Cement should inserted in a doughy state with minimal pressure to prevent cement complications.

Ablation of the basivertebral nerve for treatment of back pain: a clinical study.

BACKGROUND CONTENT: Lumbar axial back pain arising from degenerative disc disease continues to be a challenging clinical problem whether treated with nonsurgical management, local injection, or motion segment stabilization and fusion. PURPOSE: The purpose of this study was to determine the efficacy of intraosseous basivertebral nerve (BVN) ablation for the treatment of chronic lumbar back pain in a clinical setting. STUDY DESIGN: Patients meeting predefined inclusion or exclusion criteria were enrolled in a study using radiofrequency energy to ablate the BVN within the vertebral bodies adjacent to the diagnosed level. Patients were evaluated at 6 weeks, and 3, 6, and 12 months postoperatively. PATIENT SAMPLE: Seventeen patients with chronic, greater than 6 months, low back pain unresponsive to at least 3 months of conservative care were enrolled. Sixteen patients were treated successfully following screening using magnetic resonance imaging finding of Modic type I or II changes and positive confirmatory discography to determine the affected levels. The treated population consisted of eight male and eight female patients; the mean age was 48 years (34-66 years). OUTCOME MEASURES: Self-reported outcome measures were collected prospectively at each follow-up interval. Measures included the Oswestry Disability Index (ODI), visual analogue scale score, and Medical Outcomes Trust 36-Item Short-Form Health Survey (SF-36). MATERIALS AND METHODS: This is an industry-sponsored study to evaluate the effectiveness of intraosseous nerves in the treatment of chronic back pain. Consented and enrolled patients underwent ablation of the BVN using radiofrequency energy (INTRACEPT System, Relievant Medsystems, Inc, Redwood City, CA, USA) guided in a transpedicular or extrapedicular approach. Preoperative planning determined targeted ablation zone and safety zones. RESULTS: Mean baseline ODI of the treated cohort was 52±13, decreasing to a mean of 23±21 at 3 months follow-up (p<.001). The statistically significant improvement in ODI observed at 3 months was maintained through the 12-month follow-up. The mean baseline visual analogue scale score decreased from 61±22 to 45±35 at 3 months follow-up (p<.05), and the mean baseline physical component summary increased from 34.5±6.5 to 41.7±12.4 at 3 months follow-up (p=.03). CONCLUSION: Ablation of the BVN for the treatment of chronic lumbar back pain significantly improves patients' self-reported outcome early in the follow-up period; the improvement persisted throughout the 1-year study period.

Effect of a stress management program on subjects with neck pain: A pilot randomized controlled trial.

BACKGROUND: Studies have shown that stress is implicated in the cause of neck pain (NP). OBJECTIVES: The purpose of this study is to examine the effect of a simple, zero cost stress management program on patients suffering from NP. METHODS: This study is a parallel-type randomized clinical study. People suffering from chronic non-specific NP were chosen randomly to participate in an eight week duration program of stress management (N= 28) (including diaphragmatic breathing, progressive muscle relaxation) or in a no intervention control condition (N= 25). Self-report measures were used for the evaluation of various variables at the beginning and at the end of the eight-week monitoring period. Descriptive and inferential statistic methods were used for the statistical analysis. RESULTS: At the end of the monitoring period, the intervention group showed a statistically significant reduction of stress and anxiety (p= 0.03, p= 0.01), report of stress related symptoms (p= 0.003), percentage of disability due to NP (p= 0.000) and NP intensity (p= 0.002). At the same time, daily routine satisfaction levels were elevated (p= 0.019). No statistically significant difference was observed in cortisol measurements. CONCLUSIONS: Stress management has positive effects on NP patients.

Safety and effectiveness of retrorectal presacral approach for lumbosacral axial instrumentation. A clinical study.

This prospective study aimed to quantify the risks and complications associated with AxiaLIF in a series of 29 patients. AxiaLIF is a fusion technique using a percutaneous retrorectal, presacral corridor approach to access the L5-S1 and L4-L5 intervertebral spaces transaxially, through the body of S1 and L5 vertebrae. The fusion rate in the present series was 92% and the reported results ranged from 68% to 100%. The only serious complication in the authors' series was one presacral haematoma (1/29, or 35%). Symptomatic subsidence occurred in the stand alone group, resulting in foraminal stenosis and radiculopathy in two patients (7%) and back pain in one (3.5%). Painful radiolucent halo around the rod was noted in a spondylolytic case (1/29, or 3.5%); it resolved after transpedicular instrumentation. AxiaLIF is a novel truly minimally invasive technique not requiring blood transfusion and can be safely performed as a day surgery. Retroperitoneal haematoma, ureteral and vascular injuries can be avoided by respecting the regional anatomical landmarks as guided by accurate fluoroscopy. Only expanding haematomas may have to be drained. Bowel perforation can be prevented by gently sweeping away the rectum from the sacrum before inserting the guide probe.

Quality assessment systems in rehabilitation services for people with a disability in Greece: a critical review.

BACKGROUND: Despite international interest on quality assessment systems (QAS) and their importance in health care accreditation, implementation of a Rehabilitation Services Quality Measurement System still remains a neglected subject in Greece. OBJECTIVE: To identify appropriate tools for researchers and policy makers to assess the quality of rehabilitation services in Greece, within the current active debate on national health care reform. METHODS: A critical review methodology was undertaken, using a systematic approach, aiming to identify the most appropriate tools in the field. Multi-step strategy was followed to gather relevant data, including bibliographical database, internet and hand searches. RESULTS: Twenty-two studies, articles and documents were identified as meeting all inclusion criteria, representing four QAS, compared according to appropriateness, efficiency, and feasibility for general use. The European Quality in Social Services (EQUASS) was evaluated as meeting all of the desired features, such as proper certification, objective measuring, equality, education and training, established guidelines and person-centered approach. CONCLUSIONS: EQUASS initiative, developed according to European standards and implemented in resource-limited settings, was recognized as the most adaptive and appropriate system for Greek rehabilitation settings. Health policy makers are urged to take findings into consideration in establishing an integrated, quality-assured rehabilitation system throughout the country.

Hematogenous pyogenic spinal infection: current perceptions.

EDUCATIONAL OBJECTIVES: As a result of reading this article, physicians should be able to:1.Understand the importance of early diagnosis and treatment of spinal infection in an effort to avoid devastating and crippling complications such as paralysis, painful deformity, and death.2.Understand current perceptions in the ongoing debate of whether operative or conventional treatment should be preferred and in which cases.3.Understand the latest advances in the surgical treatment of spinal infection, their indications, and their effectiveness.4.Understand the change in the traditionally held belief that in the presence of infection, the use of metal implants or grafts is not indicated. Controversy exists regarding optimal treatment for pyogenic spinal infection. The authors systematically reviewed peer-reviewed published clinical trials in the English language through 2009 on the clinical presentation, complications, and conservative and operative treatments of pyogenic spinal infection. The cornerstone of therapy for uncomplicated spondylodiskitis is intravenous antibiotics followed by oral antibiotics and bracing. Surgery is effective in complicated cases and improves sagittal balance, restores neurological impairment, and relieves severe pain. In cases of delayed diagnosis or surgery, potential early devastating and late crippling complications may occur. To the authors' knowledge, no Level I studies compare operative vs conservative treatment of pyogenic spinal infection.

Respiratory effects, hemodynamic changes and cement leakage during multilevel cement balloon kyphoplasty.

PURPOSE: The purpose of this study is to evaluate the effects of multilevel balloon kyphoplasty (BK) on blood pressure, blood gases and cement leakage. METHODS: This is a prospective study of 63 patients: 31 were treated for osteoporotic vertebral compressive fractures (OVCF) and 32 for osteolytic tumors (OT). Twenty-six patients were treated at 1 level, 15 at 2, 2 at 3, 6 at 4, 3 at 5, 4 at 6, 5 at 7 and 2 at 8. PPMA was used in 43 patients and calcium phosphate in 20. All patients were treated under general anesthesia with continuous invasive monitoring of hemodynamic changes, arterial blood gases and peripheral and regional cerebral oxygen saturation. RESULTS: Two patients had a transient drop in blood pressure between 21 and 42 % during simultaneous inflation of all four balloons at two levels and three more patients during cement injection (two PMMA, one calcium phosphate). Five patients had a cement leak (7.9 %), which was unrelated to the cement type or number of levels. Blood pressure, end-tidal carbon dioxide partial pressure and arterial oxygen partial pressure decreased statistically, but without any clinical significance after cement insertion. Peripheral and regional cerebral oxygen saturation remained unchanged. One-way ANOVA revealed no difference between these changes when clustered by the groups single level, two levels and three or more levels. CONCLUSION: BK performed under general anesthesia appears to be safe when applied in multiple levels in the same seating provided the balloons are inflated sequentially and not simultaneously and the cement is inserted slowly in a very doughy state. Close monitoring of cardiorespiratory factors is valuable. Its rare circulatory effects are unrelated to the number of levels or the cement type.

Lateral mass screw complications: analysis of 1662 screws.

STUDY DESIGN: Retrospective, consecutive patient series. OBJECTIVE: To quantify the risks and the complications associated with screw fixation devices of the cervical spine. SUMMARY OF BACKGROUND DATA: The usefulness of lateral mass internal fixation has been well documented in the clinical setting. However, there is a paucity of studies examining the complications associated with these devices in a degenerative clinical setting. METHODS: From 1999 to 2007, 225 consecutive patients underwent posterior cervical fixation using a screw-plate and polyaxial screw-rod implant systems. There were 105 women and 120 men (age range: 45 to 84 y; mean, 68 y). In all patients, the surgical indication was cervical spondylosis with myelopathy. Mean follow-up interval was 18 months (range: 12 to 72 mo). Screw position was evaluated by computed tomography scanning postoperatively in all patients. Clinical and radiographic outcome was assessed at each visit after surgery. RESULTS: Intraoperative complications include fracture of lateral mass in 27 screws placement and nerve irritation in 3 bicortical screws. Early complications include hematoma formation in 2 cases and C5 root palsy in 5 cases after spinal canal decompression. Late complications include pseudarthrosis in 6 cases and screw pull-out in 3 cases. There were no cases of spinal cord or vertebral artery injury, infections, deaths, or adjacent segment disease. All patients had radiographic union, and no patient developed mechanical implant failure requiring removal of instrumentation. Reoperation was required in 14 (6.2%) cases because of nerve injury, hematoma formation, pseudarthrosis, and screw pull-out. CONCLUSIONS: Our clinical findings indicate that lateral mass fixation can be used safely with minimal complications and low rate of morbidity for cervical myelopathy treatment.

Studying the association between musculoskeletal disorders, quality of life and mental health. A primary care pilot study in rural Crete, Greece.

BACKGROUND: The burden of musculoskeletal disorders (MSD) on the general health and well-being of the population has been documented in various studies. The objective of this study was to explore the association between MSD and the quality of life and mental health of patients and to discuss issues concerning care seeking patterns in rural Greece. METHODS: Patients registered at one rural Primary Care Centre (PCC) in Crete were invited to complete the Nordic Musculoskeletal Questionnaire (NMQ) for the analysis of musculoskeletal symptoms, together with validated instruments for measuring health related quality of life (SF-36) and mental distress (GHQ-28). RESULTS: The prevalence rate of MSD was found to be 71.2%, with low back and knee pain being the most common symptoms. Most conditions significantly impaired the quality of life, especially the physical dimensions of SF-36. Depression was strongly correlated to most MSD (p < 0.001). Multiple logistic analyses revealed that patients who consulted the PCC due to MSD were likely to have more mental distress or impaired physical functioning compared to those who did not. CONCLUSION: Musculoskeletal disorders were common in patients attending the rural PCC of this study and were associated with a poor quality of life and mental distress that affected their consultation behaviour.

Anterior cervical discectomy and fusion with a locked plate and wedged graft effectively stabilizes flexion-distraction stage-3 injury in the lower cervical spine: a biomechanical study.

STUDY DESIGN: An in vitro three-dimensional (3D) flexibility test of human C3-C7 cervical spine specimens. OBJECTIVE: To test the hypothesis that anterior cervical fusion with a wedged graft and a locked plate can effectively stabilize the cervical spine after complete anterior and posterior segmental ligamentous release. SUMMARY OF BACKGROUND DATA: Distraction-flexion Stage 3 injuries of the lower cervical spine (bilateral facet dislocations) are usually reduced under awake cranial traction. When the magnetic resonance imaging reveals a traumatic disc prolapse, anterior cervical discectomy and fusion (ACDF) is usually recommended. Most authors advise combining ACDF with posterior instrumentation to address the insufficiency of the posterior elements. However, there is clinical evidence that ACDF with a locked plate alone suffices for the treatment of these injuries, especially in young patients. Still, there are no biomechanical studies on the effect of a locked plate on the complete anterior and posterior ligamentous-deficient young cervical spine under physiologic preload. METHODS: Eight fresh frozen human lower cervical spines (C3-C7) from young donors (age, 44.5 years; range, 21-63 years) were used. A 3D flexibility test was conducted using a moment of 0.8 Nm without preload. Flexion-extension was additionally tested using a moment of 1.5 Nm under 0 and 150 N follower preload. Spines were tested first intact, then after complete C5-C6 discectomy with posterior longitudinal ligament resection and ACDF with a wedged bone graft and a rigid locked plate, and finally after complete release of the supraspinous, interspinous, and intertransverse ligaments; the facet capsules; and ligamentum flavum. RESULTS.: When tested under 0.8 Nm moment without preload, complete posterior and anterior ligamentous release did not significantly increase the ROM of the ACDF construct in flexion-extension (P > 0.025), lateral bending (P > 0.025), and axial rotation (P > 0.025). When tested under 1.5 Nm moment with or without a compressive preload, the complete posterior and anterior ligamentous release did not significantly affect the ROM of the ACDF construct (P > 0.01). The application of preload significantly reduced the motion at the C5-C6 ACDF construct with ligamentous disruption in comparison with the motion in the absence of a preload (P < 0.01). CONCLUSION: Anterior cervical fusion with a wedged graft and a rigid constrained (locked) plate can effectively stabilize the nonosteoporotic cervical spine after complete posterior element injury when excessive ROM is prevented (for example, by the use of postoperative external immobilization). Even when the construct is subjected to higher moments, adequate stability can be achieved when physiologic preload is present. Osteoporosis and lack of sufficient preload due to poor neuromuscular control may affect long-term screw stability, and additional external immobilization may be needed until fusion matures.

Percutaneous core excision and radiofrequency thermo-coagulation for the ablation of osteoid osteoma of the spine.

Percutaneous radiofrequency ablation is the treatment of choice for osteoid osteoma of the appendicular skeleton. However, difficulties in localizing the lesion in the spine and its proximity to neural elements have yet to make it the prevalent treatment for spine. This study assesses the safety and effectiveness of two percutaneous techniques for ablating osteoid osteoma of the spine. Seven patients were treated between 1998 and 2005. Four patients underwent percutaneous radiofrequency coagulation. The lesions were located at the articular processes of L3 and L4, the lamina of L3 and in the head of the 11th rib. Three patients with lesions in close proximity to neural structures (pedicle of T9, the posterolateral inferior aspect of L3 vertebral body and the inferior articular process of C5) were subjected to percutaneous core excision. Mean follow-up was 4.2 +/- 1.6 years. Three out of four patients who underwent radiofrequency ablation had an immediate and sustained response. One patient with a lesion in the head of the rib failed to respond. The three patients in the group of pecutaneous core excisional biopsy demonstrated immediate relief of pain. However, one patient experienced relapse of symptoms 6 months after transpedicular core excision. CT scan suggested partial targeting of the lesion that corroborated with histologic examination revealing only reactive tissue. Subsequent percutaneous core excision was successful. Therefore, the overall success rate was 85.7%. Mean VAS improved dramatically from 9 +/- 1 to 2 +/- 1 after surgery (P < 0.05). No neurological or other complications were encountered. This study indicates that radiofrequency ablation of spinal osteoid osteomas is safe and reasonably effective when an intact cortical shell separates the nidus from the neural elements. Percutaneous core excision can obviate the risk of thermal damage for lesions located in close proximity to the neural elements. Effectiveness of treatment can also be evaluated by CT scan and histological examination. Difficulties in targeting the nidus can lead to treatment failure. The minimal morbidity and the effectiveness of these minimally invasive procedures make them a valid alternative in the treatment of spinal osteoid osteoma.

Beneficial influence of titanium mesh cage on infection healing and spinal reconstruction in hematogenous septic spondylitis: a retrospective analysis of surgical outcome of twenty-five consecutive cases and review of literature.

STUDY DESIGN: Single institution, single surgeon retrospective review. OBJECTIVE: To investigate if the use of titanium mesh cage on the site of infection could be beneficial for successful outcome of the operative treatment for pyogenic spondylitis. SUMMARY OF BACKGROUND DATA: There is a controversy concerning the optimal treatment for pyogenic spondylitis regarding approach, instrumentation and staging. This large series reports on single-stage instrumented open and minimally invasive surgery for septic spondylitis. METHODS: Twenty-four patients aged 57 +/- 16 years suffering from persistent or complicated septic spondylitis were treated by a total of 25 single stage combined surgeries (first: anterior debridement/partial vertebrectomy plus mesh cage filled with autologous bone graft; second: pedicle screw fixation with open and minimal invasive techniques). The indications for surgery included neurologic compromise, significant vertebral body destruction with kyphosis associated with segmental instability, failure of medical treatment, and/or epidural/ paravertebral abscess formation. Needle biopsy was performed in all patients before surgery. Patients were evaluated before and after surgery in terms of pain and neurologic level, sagittal segmental spinal balance, radiologic fusion and recovery. RESULTS: All but 1 tetraplegic patient with simultaneous cervical and lumbar spondylitis, who died because of massive clot lung embolism 2 months after surgery, were followed for 56 months (range, 31-116 months) The visual analogue scale score improved from 6.5 before surgery to 1.8 after surgery. The segmental kyphotic deformity was corrected at an average of 6 degrees, without cage settling. An insignificant loss of kyphosis correction of an average 0.6 degrees was measured in the thoracolumbar junction only. Blood loss, surgical time, and surgical complications were significant less in the patients who operated with minimal invasive technique. Patients with incomplete neurologic impairment improved after surgery. Physical function (SF-36) averaged 72 1 year after surgery. All operated patients had resolution of infection. There was neither migration of mesh cage nor posterior instrumentation failure at the last follow-up observation. CONCLUSION: The present study showed that radical debridement of spinal infection and anterior insertion of titanium cage, filled with autogenous bone graft, secured with pedicle screw instrumentation should have had a beneficial influence on the eradication of infection, segmental and global spinal reconstruction and fusion. Supplementary posterior minimal invasive pedicle screw fixation eliminates posterior soft tissue injury and preserves blood supply, and reduces surgical time, blood loss, and surgical complications.

Altered disc pressure profile after an osteoporotic vertebral fracture is a risk factor for adjacent vertebral body fracture.

This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 +/- 14%. After cementation, disc pressure increased during flexion by 15 +/- 11% in the discs with un-fractured endplates, while decreased by 19 +/- 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 +/- 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 +/- 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that correction of endplate deformity may play a role in reducing the risk of adjacent fractures.

Intradural tumours of the lumbar spine presenting with low back pain: report of two cases and review of the literature.

Two cases of spinal cord tumours (one schwannoma and one ependymoma) of the lumbar spine are reported. The treatment with radical excision and posterolateral fusion, along with adjuvant radiation therapy in the case with ependymoma was successful, with follow-up of six and seven years respectively. A literature review is presented, and a possible presentation with low back pain is analysed.