Intradiscal oxygen-ozone chemonucleolysis versus microdiscectomy for lumbar disc herniation radiculopathy: a non-inferiority randomized control trial.

BACKGROUND CONTEXT: Low back pain with or without radicular leg pain is an extremely common health condition significantly impacting patient's activities and quality of life. When conservative management fails, epidural injections providing only temporary relief, are frequently utilized. Intradiscal oxygen-ozone may offer an alternative to epidural injections and further reduce the need for microdiscectomy. PURPOSE: To compare the non-inferiority treatment status and clinical outcomes of intradiscal oxygen-ozone with microdiscectomy in patients with refractory radicular leg pain due to single-level contained lumbar disc herniations. STUDY DESIGN / SETTING: Multicenter pilot prospective non-inferiority blocked randomized control trial conducted in three European hospital spine centers. PATIENT SAMPLE: Forty-nine patients (mean 40 years of age, 17 females/32 males) with a single-level contained lumbar disc herniation, radicular leg pain for more than six weeks, and resistant to medical management were randomized, 25 to intradiscal oxygen-ozone and 24 to microdiscectomy. 88% (43 of 49) received their assigned treatment and constituted the AS-Treated (AT) population. OUTCOME MEASURES: Primary outcome was overall 6-month improvement over baseline in leg pain. Other validated clinical outcomes, including back numerical rating pain scores (NRS), Roland Morris Disability Index (RMDI) and EQ-5D, were collected at baseline, 1 week, 1-, 3-, and 6-months. Procedural technical outcomes were recorded and adverse events were evaluated at all follow-up intervals. METHODS: Oxygen-ozone treatment performed as outpatient day surgeries, included a one-time intradiscal injection delivered at a concentration of 35±3 µg/cc of oxygen-ozone by a calibrated delivery system. Discectomies performed as open microdiscectomy inpatient surgeries, were without spinal instrumentation, and not as subtotal microdiscectomies. Primary analyses with a non-inferiority margin of -1.94-point difference in 6-month cumulative weighted mean leg pain NRS scores were conducted using As-Treated (AT) and Intent-to-Treat (ITT) populations. In post hoc analyses, differences between treatment groups in improvement over baseline were compared at each follow-up visit, using baseline leg pain as a covariate. RESULTS: In the primary analysis, the overall 6-month difference between treatment groups in leg pain improvement using the AT population was -0.31 (SE, 0.84) points in favor of microdiscectomy and using the ITT population, the difference was 0.32 (SE, 0.88) points in favor of oxygen-ozone. The difference between oxygen-ozone and microdiscectomy did not exceed the non-inferiority 95% confidence lower limit of treatment difference in either the AT (95% lower limit, -1.72) or ITT (95% lower limit, -1.13) populations. Both treatments resulted in rapid and statistically significant improvements over baseline in leg pain, back pain, RMDI, and EQ-5D that persisted in follow-up. Between group differences were not significant for any outcomes. During 6-month follow-up, 71% (17 of 24) of patients receiving oxygen-ozone, avoided microdiscectomy. The mean procedure time for oxygen-ozone was significantly faster than microdiscectomy by 58 minutes (p<.0010) and the mean discharge time from procedure was significantly shorter for the oxygen-ozone procedure (4.3±2.9 hours vs. 44.2±29.9 hours, p<.001). No major adverse events occurred in either treatment group. CONCLUSIONS: Intradiscal oxygen-ozone chemonucleolysis for single-level lumbar disc herniations unresponsive to medical management, met the non-inferiority criteria to microdiscectomy on 6-month mean leg pain improvement. Both treatment groups achieved similar rapid significant clinical improvements that persisted and overall, 71% undergoing intradiscal oxygen-ozone were able to avoid surgery.

The 'armed concrete' approach: stent-screw-assisted internal fixation (SAIF) reconstructs and internally fixates the most severe osteoporotic vertebral fractures.

BACKGROUND: The treatment of severe osteoporotic vertebral compression fractures (VCFs) with middle-column (MC) involvement, high fragmentation, large cleft and/or pedicular fracture is challenging. Minimally invasive 'stent-screw-assisted internal fixation' (SAIF) can reduce the fracture, reconstruct the vertebral body (VB) and fix it to the posterior elements. OBJECTIVE: To assess feasibility, safety, technical and clinical outcome of the SAIF technique in patients with severe osteoporotic VCFs. METHODS: 80 treated vertebrae were analyzed retrospectively. Severe VCFs were characterized by advanced collapse (Genant grade 3), a high degree of osseous fragmentation (McCormack grade 2 and 3), burst morphology with MC injury, pediculo-somatic junction fracture, and/or large osteonecrotic cleft. VB reconstruction was evaluated on postprocedure radiographs and CT scans by two independent raters. Clinical and radiological follow-ups were performed at 1 and 6 months. RESULTS: SAIF was performed at 28 thoracic and 52 lumbar levels in 73 patients. One transient neurological complication occurred. VB reconstruction was satisfactory in 98.8% of levels (inter-rater reliability 96%, κ=1). Follow-up at 1 month was available for 78/80 levels and at 6 months or later (range 6-24, mean 7.9 months) for 73/80 levels. Significant improvement in the Visual Analog Scale score was noted at 1 and 6 months after treatment (p<0.05). Patients reported global clinical benefit during follow-up (Patient's Global Impression of Change Scale 5.6±0.9 at 1 month and 6.1±0.9 at 6 months). Fourteen new painful VCFs occurred at different levels in 11 patients during follow-up, treated with vertebral augmentation or SAIF. Target-level stability was maintained in all cases. CONCLUSIONS: SAIF is a minimally invasive, safe, and effective treatment for patients with severe osteoporotic VCFs with MC involvement.

Stent screw-assisted internal fixation (SAIF): clinical report of a novel approach to stabilizing and internally fixating vertebrae destroyed by malignancy.

OBJECTIVE: Severe lytic cancerous lesions of the spine are associated with significant morbidity and treatment challenges. Stabilization and restoration of the axial load capability of the vertebral body (VB) are important to prevent or arrest vertebral collapse. Percutaneous stent screw-assisted internal fixation (SAIF), which anchors a VB stent/cement complex with pedicular screws to the posterior vertebral elements, is a minimally invasive, image-guided, 360° internal fixation technique that can be utilized in this patient cohort. The purpose of this study was to assess the feasibility, safety, and stabilization efficacy of VB reconstruction via the SAIF technique in a cohort of patients with extensive lytic vertebral lesions, who were considered to have an unstable or potentially unstable spine according to the Spinal Instability Neoplastic Score (SINS). METHODS: This study was a retrospective assessment of a prospectively maintained database of a consecutive series of patients with neoplastic extensive extracompartmental osteolysis (Tomita type 4-6) of the VB treated with the SAIF technique. VB reconstruction was assessed on postprocedure plain radiographs and CT by two independent raters. Technical and clinical complications were recorded. Clinical and imaging follow-ups were assessed. RESULTS: Thirty-five patients with extensive osteolytic metastatic lesions of the VB underwent 36 SAIF procedures. SAIF was performed as a stand-alone procedure in 31/36 cases and was associated with posterior surgical fixation in 5/36 (4/5 with decompressive laminectomy). In 1 case an epidural cement leak required surgical decompression. VB reconstruction was categorized as satisfactory (excellent or good rating) by the two raters in 34/36 cases (94.5%) with an interrater reliability of 94.4% (Cohen's kappa of 0.8). Follow-up, ranging from 1 to 30 months, was available for 30/36 levels. Long-term follow-up (6-30 months, mean 11.5 months) was available for 16/36 levels. Stability during follow-up was noted in 29/30 cases. CONCLUSIONS: SAIF provides 360° nonfusion internal fixation that stabilizes the VB in patients with extensive lytic lesions that would otherwise be challenging to treat.

Stent-Screw Assisted Internal Fixation of Osteoporotic Vertebrae: A Comparative Finite Element Analysis on SAIF Technique.

Vertebral compression fractures are one of the most relevant clinical consequences caused by osteoporosis: one of the most common treatment for such fractures is vertebral augmentation through minimally invasive approaches (vertebroplasty or balloon-kyphoplasty). Unfortunately, these techniques still present drawbacks, such as re-fractures of the treated vertebral body with subsidence of the non-augmented portions or re-fracture of the non-augmented middle column at the junction with the augmented anterior column. A novel minimally-invasive augmentation technique, called Stent-Screw Assisted Internal Fixation, has been recently proposed for the treatment of severe osteoporotic and neoplastic fractures: this technique uses two vertebral body stents and percutaneous cannulated and fenestrated pedicular screws, through which cement is injected inside the expanded stents to achieve optimal stents' and vertebral body's filling. The role of the pedicle screws is to anchor the stents-cement complex to the posterior column, acting as a bridge across the middle column and preserving its integrity from possible collapse. In order to evaluate the potential of the new technique in restoring the load bearing capacity of the anterior and middle spinal columns and in reducing bone strains, a Finite Element model of an osteoporotic lumbar spine has been developed. Both standard vertebroplasty and Stent-Screw Assisted Internal Fixation have been simulated: simulations have been run taking into account everyday activities (standing and flexion) and comparison between the two techniques, in terms of strain distribution on vertebral endplates and posterior and anterior wall, was performed. Results show that Stent-Screw Assisted Internal Fixation significantly decrease the strain distribution on the superior EP and the cortical wall compared to vertebroplasty, possibly reducing the re-fracture risk of the middle-column at the treated level.

Stent Screw-Assisted Internal Fixation (SAIF) of Severe Lytic Spinal Metastases: A Comparative Finite Element Analysis of the SAIF Technique.

OBJECTIVE: A new stent-screw-assisted internal fixation (SAIF) minimally invasive cement-augmentation technique has been introduced to treat patients with extreme osteolytic lesions of the vertebral body. The aim of the current finite element study, employing a spine model with an extreme osteolytic defect, was to assess the effect of the SAIF technique in reducing strains in the vertebral body in comparison with a standard surgical short posterior fixation. METHODS: Different finite element models of a L1-S1 spine were developed, representing an intact condition (reference configuration), an extreme osteolysis condition, and its treatment, respectively with stand-alone SAIF, SAIF and posterior fixation, and with stand-alone posterior fixation. Each model was loaded to reproduce standing and upper body bending. Principal strains were calculated on the superior endplate, anterior and posterior cortical walls. A paired Wilcoxon test with a 0.05 significance level was performed to statistically analyze the results. RESULTS: Median strains on the bony structures increased in the osteolysis model compared with the intact model, and the SAIF technique was effective in reducing such strains under both standing and flexion conditions. Additional posterior fixation, combined with the SAIF technique, produced minimal further reduction of the median strains on the bony structures. Stand-alone posterior fixation only shielded the osteolytic vertebra avoiding excessive displacements but failed in restoring the axial stiffness to values typical of the intact vertebra. CONCLUSIONS: The new SAIF technique resulted effective in restoring the load-bearing capacity of the extensively osteolytic vertebra; additional posterior fixation provided only further minor advantages.

Vertebral body stent augmentation to reconstruct the anterior column in neoplastic extreme osteolysis.

BACKGROUND: Extensive lytic lesions of the vertebral body (VB) increase risk of fracture and instability and require stabilization of the anterior column. Vertebral augmentation is an accepted treatment option, but when osteolysis has extensively destroyed the VB cortical boundaries (a condition herein defined as 'extreme osteolysis'), the risk of cement leakage and/or insufficient filling is high. Vertebral body stents (VBSs) might allow partial restoration of VB height, cement containment, and reinforcement, but their use in extreme osteolysis has not been investigated. OBJECTIVE: To assess retrospectively the feasibility and safety of VBS augmentation in patients with 'extreme osteolysis' of the VB. METHODS: We retrospectively analyzed 41 treated vertebrae (from T1 to L5). VB reconstruction was assessed on postprocedure CT images and rated on a qualitative 4-point scale (poor-fair-good-excellent). Clinical and radiological follow-up was performed at 1 month and thereafter at intervals in accordance with oncological protocols. RESULTS: VBS augmentation was performed at 12 lumbar and 29 thoracic levels, with bilateral VBS in 23/41. VB reconstruction was judged satisfactory (good or excellent) in 37/41 (90%) of levels. Bilateral VBS received higher scores than unilateral (p=0.057, Pearson's X2). We observed no periprocedural complications. Cement leaks (epidural or foraminal) occurred at 5/41 levels (12.2%) without clinical consequences. Follow-up data were available for 27/29 patients, extending beyond 6 months for 20 patients (7-28 months, mean 15.3 months). VBS implant stability was observed in 40/41 cases (97.5%). CONCLUSIONS: Our results support the use of VBS as a minimally invasive, safe and effective option for reconstructing the anterior column in prominent VB osteolysis.

Stent-screw-assisted internal fixation: the SAIF technique to augment severe osteoporotic and neoplastic vertebral body fractures.

OBJECTIVES: To describe a new technique to obtain minimally invasive but efficient vertebral body (VB) reconstruction, augmentation, and stabilization in severe osteoporotic and neoplastic fractures, combining two pre-existing procedures. The implant of vertebral body stents (VBS) is followed by insertion of percutaneous, fenestrated, cement-augmented pedicular screws that act as anchors to the posterior elements for the cement/stent complex. The screws reduce the risk of stent mobilization in a non-intact VB cortical shell and bridge middle column and pedicular fractures. This procedure results in a 360° non-fusion form of vertebral internal fixation that may empower vertebral augmentation and potentially avoid corpectomy in challenging fractures. PROCEDURE DETAILS: This report provides step-by-step procedural details, rationale, and proposed indications for this procedure. The procedure is entirely percutaneous under fluoroscopic guidance. Through transpedicular trocars the VBS are inserted, balloon-expanded and implanted in the VB. Over k-wire exchange the transpedicular screws are inserted inside the lumen of the stents and cement is injected through the screws to augment the stents and fuse the screws to the stents. APPLICATIONS: This technique may find appropriate applications for the most severe osteoporotic fractures with large clefts, high-degree fragmentation and collapse, middle column and pedicular involvement, and in extensive neoplastic lytic lesions. CONCLUSIONS: Stent-Screw-Assisted Internal Fixation (SAIF) might represent a minimally invasive option to obtain VB reconstruction and restoration of axial load capability in severe osteoporotic and neoplastic fractures, potentially obviating the need for more invasive surgical interventions in situations that would pose significant challenges to standard vertebroplasty or balloon kyphoplasty.

Craniovertebral junction instability as an extension of cocaine-induced midline destructive lesions: case report.

With the increasingly widespread illicit use of cocaine, a broad spectrum of clinical pathologies related to this form of drug abuse is emerging. The most frequently used method of administration of powdered cocaine is intranasal inhalation, or "snorting." Consequently, adverse effects of cocaine on the nasal tract are common. Habitual nasal insufflations of cocaine can cause mucosal lesions. If cocaine use becomes chronic and compulsive, progressive damage of the mucosa and perichondrium leads to ischemic necrosis of the septal cartilage and perforation of the nasal septum. Occasionally, cocaine-induced lesions cause extensive destruction of the osteocartilaginous structures of the nose, sinuses, and palate and can mimic other diseases such as tumors, infections, and immunological diseases. In the literature currently available, involvement of the craniovertebral junction in the cocaine-induced midline destructive lesions (CIMDLs) has never been reported. The present case concerns a 44-year-old man who presented with long-standing symptoms including nasal obstruction, epistaxis, dysphagia, nasal reflux, and severe neck pain. A diagnosis of CIMDL was made in light of the patient's history and the findings on physical and endoscopic examinations, imaging studies, and laboratory testing. Involvement of the craniovertebral junction in the destructive process was evident. For neurosurgical treatment, the authors considered the high grade of atlantoaxial instability, the poorly understood cocaine-induced lesions of the spine and their potential evolution overtime, as well as cocaine abusers' poor compliance. The patient underwent posterior craniovertebral fixation. Understanding, classifying, and treating cocaine-induced lesions involving the craniovertebral junction are a challenge.

Transarticular laser discal fragmentectomy. A new minimally invasive surgical approach for challenging disc herniations in the elderly.

This report describes two elderly patients with large disc fragments extruded into lumbar radicular recesses not treatable by any conventional conservative, minimally invasive or surgical approach. Direct access to the disc fragments was obtained crossing the articular zygapophyseal cavity instead of the interlaminar space and spinal canal, using a small needle through which a laser fibre was inserted to deliver energy for tissue ablation. The procedures obtained regression of both symptoms and the bulk of the fragments at early and late clinical and MR follow-ups.

Combining percutaneous pedicular and extrapedicular access for tumor ablation in a thoracic vertebral body.

We present a percutaneous modified technique to access large thoracic vertebral body lytic lesions, to increase the volume of tumor accessible to ablation, prior to cement augmentation. Tumor ablation and cavity creation-assisted percutaneous vertebroplasty was considered a palliative measure for structural stabilization in plasmocytoma involvement of the entire T8 vertebral body. Given the extent of osteolysis bilateral combined transpedicular and extrapedicular access to the vertebral body was undertaken to maximize the volume of cavity creation within the tumor. The combined transpedicular and extrapedicular access was feasible, uncomplicated, and successful in reaching all the quadrants of the anterior two thirds of the vertebral body. Slow, fluoroscopically monitored injection of high-viscosity cement resulted in a successful, desired cement distribution into the anterior two thirds of the vertebral body, spanning superior to inferior endplates, providing structural stability, in the absence of venous or epidural leakage. The technical modification described in this case yielded positive results while overcoming some of the limitations of the existing coblation device. This approach may offer an option for cement augmentation of extensive vertebral body lytic lesions, at increased risk for tumor displacement and extra-vertebral cement leakage.

Cervical Bone Graft Candida albicans Osteomyelitis: Management Strategies for an Uncommon Infection.

Candida osteomyelitis in the current literature is an emerging infection. The factors contributing to its emergence include a growing population of immunosuppressed patients, invasive surgeries, broad-spectrum antibiotics, injection drug users, and alcohol abuse. The diagnosis requires a high degree of suspicion. The insidious progression of infection and the nonspecificity of laboratory and radiologic findings may contribute to a delay in diagnosis. The current case concerns a 27-year-old man with a spinal cord injury who, after undergoing anterior cervical fixation and fusion surgery, developed postoperative systemic bacterial infection and required long-term antibiotic therapy. After six months, a CT scan demonstrated an almost complete anterior dislocation of the implants caused by massive bone destruction and reabsorption in Candida albicans infection. The patient underwent a second intervention consisting firstly of a posterior approach with C4-C7 fixation and fusion, followed by a second anterior approach with a corpectomy of C5 and C6, a tricortical bone grafting from the iliac crest, and C4-C7 plating. The antifungal therapy with fluconazole was effective without surgical debridement of the bone graft, despite the fact that signs of the bone graft being infected were seen from the first cervical CT scans carried out after one month.

Tilting the gantry for CT-guided spine procedures.

Percutaneous spine procedures can be performed with computed tomography (CT) guidance. The use of CT guidance is cumbersome for procedures where an oblique needle trajectory is imposed by the spatial orientation of the spine, often requiring complex needle triangulation relative to the true axial scan plane. We describe a procedural modification to overcome this limitation. A combination of variable CT gantry tilt, and strategic bolster placement under the patient can be used to obtain optimal imaging planes for guidance along the desired needle trajectory. The needle is aligned with the CT gantry laser beam to guide the needle access to the target, maintained within a single CT slice. We describe our clinical experience using the modified procedure relative to the conventional technique, and provide representative examples.

Percutaneous ethanol embolization and cement augmentation of aggressive vertebral hemangiomas at two adjacent vertebral levels.

This report describes a case of successful percutaneous direct-puncture ethanol embolization, followed by vertebroplasty, of an aggressive vertebral hemangioma (VH) involving two adjacent thoracic vertebral levels. In this case, the 78-year-old male patient presented with a 6-month history of progressive paraparesis due to spinal cord compression by a T8-T9 VH with an extensive epidural component. Follow-up demonstrated epidural component shrinkage with complete regression of symptoms at 3 months. This case suggests that exclusive percutaneous treatment may be considered for symptomatic VH even when two adjacent vertebral levels are affected.

Accuracy of CT guidance of lumbar facet joint block.

OBJECTIVE: Lumbar facet joint block is generally performed under fluoroscopic guidance. The purpose of this study was to assess the technical success rate of facet joint block under CT guidance. The CT scanner was operated tableside with a step-and-shoot mode for intermittent needle visualization, and the amount of radiation used to perform the procedures was estimated. CONCLUSION: CT-guided facet joint block is safe and rapid. Use of CT ensures reliable needle guidance with extremely high procedural accuracy at an effective radiation dose comparable to that of a procedure performed with 1 minute of fluoroscopic guidance.

Percutaneous vertebroplasty: multi-centric results from EVEREST experience in large cohort of patients.

PURPOSE: The purpose of this study was to prospectively evaluate results and complications of percutaneous vertebroplasty (PV) performed in 6 different Italian Centres belonging to the European VErtebroplasty RESearch Team (E.VE.RES.T) in a large series of patients. MATERIALS AND METHODS: Follow-up was obtained in 4547 patients (3211 females and 1336 males; mean age 70.2 years) that underwent PV for a total of 13.437 treated vertebrae. Procedures were performed by using fluoroscopic guidance or combined CT-fluoroscopic guidance. All patients underwent PV in local anaesthesia except for second cervical vertebrae treated with a trans-oral approach that required general anaesthesia. RESULTS: 4004 out of 4547 (88.0%) patients reported significant pain relief (difference>or=2 point in pain evaluated with an 11-point visual analogue scale; p<0.0001) within 48 h: an average of 7.7 ± 0.4 dropped to 1.8 ± 0.6 in the osteoporotic patients; 8.3 ± 0.4 to 2.4 ± 0.4 in metastases; 8.3 ± 0.4 to 1.7 ± 1.0 in myeloma; 6.2 ± 3.5 to 0.3 ± 0.2 in angioma and 7.4 ± 0.4 to 1.4 ± 0.9 in trauma. 430 osteoporotic patients (13%) were retreated for a subsequent fracture; in 302/430 patients (70.2%), the new fracture occurred in the contiguous vertebra. No major neurologic complications were reported and the most frequent minor complication was venous leakage (20.5%). CONCLUSIONS: This large series of patients confirms that percutaneous vertebroplasty is an effective and safe procedure in the treatment of vertebral fractures. Best results are obtained in the treatment of myeloma and trauma.

Percutaneous cement augmentation of a lytic lesion of C1 via posterolateral approach under CT guidance.

BACKGROUND CONTEXT: Percutaneous vertebroplasty (PV) can provide pain relief and biomechanical stabilization of lytic metastasis of the spine in selected patients. Percutaneous vertebroplasty of the atlas has been reported in only five cases and has been performed with different techniques and approaches. PURPOSE: To describe the technique we used to perform PV of a lytic lesion of the lateral mass of C1 under computed tomography, computed tomography angiography, and computed tomography fluoroscopy guidance with a posterolateral approach, sparing the vertebral artery (VA). STUDY DESIGN/SETTING: Technical note. METHODS: A 36-year-old woman with a history of intestinal carcinoid tumor presented with neck pain refractory to medical treatment. Radiological evaluation showed osteolytic destruction of the left lateral mass of the atlas, at the risk of collapse, with erosion of the VA canal. Under computed tomography and computed tomography angiography guidance, a percutaneous posterolateral oblique approach to the C1 left lateral mass was performed followed by cement augmentation under computed tomography fluoroscopy control. RESULTS: Complete cement filling of the osteolytic lesion was achieved. A cement leak was noted along the horizontal V3 segment of the left VA. Computed tomography angiography scan showed patency of the VA after the procedure. There were no clinical complications. The patient reported substantial pain relief and improved range of motion at 12 hours postprocedure, which remained stable at 2-month follow-up examination. CONCLUSIONS: Computed tomography-guided PV of C1 lytic lesion with posterolateral approach was effective in the described case for pain control and stabilization, and it may be a therapeutic option in selected patients to avoid occipitocervical fusion. This procedure requires good understanding of the anatomy and rigorous technique to avoid potential complications.

Vertebral augmentation: 7 years experience.

Percutaneous vertebroplasty and kyphoplasty are procedures used to treat pain associated with vertebral compression fractures. Controversies are still open regarding indications, efficacy and safety of the procedures, and regarding the potential benefits, advantages and shortcomings of PV versus KP.Aim of this article is to report 7 years' experience in vertebral augmentation of the E.VE.RES.T. (European VErtebroplasty RESearch Team) group. The main topics are the treatments of hemangioma and malignant lesions, technically challenging cases such as vertebra plana, multifragmented fractures, multilevel treatments, refracture of augmented vertebra, and treatment of cervical junction and sacrum.

Minimally invasive dynamic stabilization of the degenerated lumbar spine.

Fusion techniques are considered the gold standard for treatment of lumbar spinal instability, although there are many shortcomings and disadvantages. In the past two decades the concept of dynamic stabilization has been introduced in clinical practice. A more thorough knowledge of the spinal biomechanics has led to the ability to modify the loads within the spinal unit. Many different devices based on this concept were designed. Almost all these devices are percutaneous or minimally invasive. Thus, not only surgeons but also interventional radiologists can play a major role in the treatment of the degenerated spine.

Drug-eluting versus bare metal coronary stents: long-term human pathology. Findings from different coronary arteries in the same patient.

A 71-year-old woman underwent right coronary artery (RCA) bare metal stenting during an acute myocardial infarction. Seven months later the patient received a sirolimus-eluting stent as treatment for an 80% left anterior descending coronary artery (LAD) stenosis. She remained asymptomatic until she presented with unstable angina 16 months later. Angiography demonstrated subtotal occlusion of the left obtuse marginal branch. The LAD sirolimus-eluting stent showed 0% stenosis. The RCA stent showed 30% restenosis. The left obtuse marginal branch lesion was successfully stented, but the patient suffered a fatal stroke 24 hours after the coronary intervention. At autopsy the 16-month-old LAD sirolimus-eluting stent was widely patent with a minute thrombus near the ostium of a small side branch. The stent surface appeared free of any other irregularities. Scanning light microscopy showed mild neointimal thickening. Scanning electron microscopy showed > 80% endothelialization of the stent. The 24-month-old RCA bare metal stent showed mild to moderate neointimal growth with > 90% endothelialization.