Percutaneous Instrumentation Research Articles

Efficacy comparison of percutaneous pedicle instrumentation combined with vertebral fracture fixation or vertebral augmentation for treatment of osteoporotic thoracolumbar fractures in elderly patients

Objective To compare the outcomes of percutaneous pedicle instrumentation combined with vertebral augmentation or vertebra pedicle instrumentation for treatment of osteoporotic thoracolumbar fractures (OVCF) in elderly patients. Methods A retrospective case cohort study was conducted on 62 patients with OVCF manifesting non-neurological symptoms treated from January 2009 to January 2012. There were 22 males and 30 females, with a mean age of 61.3 years (range, 55 to 70 years). Fracture level was T11 in 8 patients, T12in 20, L1 in 22 and L2 in 12. Treatments included percutaneous pedicle instrumentation combined with vertebral fracture fixation in 36 patients (Group A) and percutaneous pedicle instrumentation combined with vertebral augmentation in 26 patients (Group B). Operation time, intraoperative blood loss, anterior vertebral body height, sagittal Cobb angle and visual analogue score (VAS) were compared between the two groups. Results All patients were followed up for average 46.5 months (range, 36 to 58 months). Operation time in Group A [(82.6±16.2)min] was shorter than that in Group B [(96.8±20.6) min] (P 0.05). At the final follow-up, the ratio of anterior vertebral height and Cobb angle in Group B [(87.8±2.5)%, (7.8±3.5)°] were better than these in Group A [(82.6±3.2)%, (9.1±1.8)°] (P 0.05). Bone cement leakage was seen in four patients in Group B. During the perioperative period, there were 3 patients with lung infection in Group A and 1 patient with lower limb deep vein thrombosis in Group B. No implant failure occurred in both groups. Conclusion Both procedures are effective in treating elderly patients with OVCF, but percutaneous pedicle instrumentation combined with vertebral augmentation is associated with better results in maintaining vertebral height and preventing kyphosis. Key words: Osteoporotic fractures; Spinal fractures; Fracture fixation, internal

Future Advances in Spine Surgery: The AOSpine North America Perspective.

This focus issue highlights state-of-the-art techniques, equipment, and practices in the modern era of spine surgery while providing a glimpse into the next generation of patient care. A broad range of topics are presented to cover the full spectrum of the field. Degenerative diseases are discussed in a series of 3 articles on (1) pathophysiology, management, and surgical approaches to degenerative cervical myelopathy; (2) novel approaches to degenerative thoracolumbar disease (eg, interspinous process spacers, minimally invasive/endoscopic approaches); and (3) animal models and emerging therapeutics in degenerative disk disease. Also included is a unique study aiming to establish the critically important cost-benefit relationship for spine procedures with perspectives on how value is defined and how to address variability.Primary and metastatic spine oncology are reviewed with a focus on upcoming targeted biologics, subspecialized radiotherapy (eg, proton-beam, carbon-ion, stereotactic radiosurgery), genetic profiling to stratify risk, and morbidity-reducing surgical approaches (eg, minimally invasive/endoscopic resections, percutaneous instrumentation). Trauma is discussed in 2 high-quality papers on controversies in spinal trauma and neuroprotective/neuroregenerative interventions for traumatic spinal cord injury. A stimulating article on cervical, thoracolumbar, and pediatric deformity highlights the rapid evolution of deformity surgery with a look at innovative tools (eg, high-fidelity 3-dimensional reconstructions, magnetically controlled growing rods) and their impact on quality of life. Additionally, a must-read article on surgical site infections discusses key risk factors and evidence-based preventative techniques to remain aware of. Finally, cutting-edge technologies, including computer-assisted navigation, shared-control robotics, neuromodulation, novel osteobiologics, and biomaterials, are covered in detail in a series of 3 fascinating papers on the next generation of the field.Each section intends to highlight the salient literature and afford insights from multiple key thought leaders in an effort to minimize bias and provide varied perspectives. Overall, we hope this issue provides high-quality, evidence-based data relevant to trainees and practicing surgeons while also stimulating excitement about the future of spine surgery.

Fracture reduction by postoperative mobilisation for the treatment of hyperextension injuries of the thoracolumbar spine in patients with ankylosing spinal disorders

IntroductionThe aim of this study was to evaluate results of surgical stabilisation of hyperextension injuries of the thoracolumbar spine in patients with ankylosing spinal disorders using two different treatment strategies: the conventional open rigid posterior instrumentation and percutaneous less rigid posterior instrumentation. Surgical and non-surgical complications, the postoperative radiological course, and clinical outcome at final follow-up were comparatively assessed. Moreover, we sought to discuss important biomechanical and surgical aspects specific to posterior instrumentation of the ankylosed thoracolumbar spine as well as to elaborate on the advantages and limitations of the proposed new treatment strategy involving percutaneous less rigid stabilisation and fracture reduction by postoperative mobilisation.Materials and methodsBetween January 2006 and June 2012, a consecutive series of 20 patients were included in the study. Posterior instrumentation was performed either using an open approach with rigid 6.0 mm bars (open rigid (OR) group) or via a percutaneous approach using softer 5.5 mm bars (percutaneous less rigid (PLR) group). Complications as well as the radiological course were retrospectively assessed, and patient outcome was evaluated at final follow-up using validated outcome scores (VAS Spine Score, ODI, RMDQ, Parker Mobility Score, Barthel Score and WHOQOL-BREF).ResultsSurgical complications occurred more frequently in the OR group requiring revision surgery in two patients, while there was no revision surgery in the PLR group. The rate of postoperative complications was lower in the PLR group as well (0.7 vs. 1.3 complications per patient, respectively). Fracture reduction and restoration of pre-injury sagittal alignment by postoperative mobilisation occurred within the first 3 weeks in the PLR group, and within 6 months in the OR group. The clinical outcome at final follow-up was very good in both groups with no relevant loss in VAS Spine Score (pain and function), Parker Mobility Score (mobility), and Barthel Index (social independency) compared to pre-operative values.ConclusionsThis study indicates that the proposed treatment concept involving percutaneous less rigid posterior instrumentation and fracture reduction by postoperative mobilisation is feasible, seems to facilitate adequate reduction and restoration of pre-injury sagittal alignment, and might have the potential to reduce the rate of complications in the management of hyperextension injuries of the ankylosed thoracolumbar spine.

Percutaneous Instrumentation Without Arthrodesis for Thoracolumbar Flexion-Distraction Injuries: A Review of the Literature.

Flexion-distraction injuries (FDI) represent 5% to 15% of traumatic thoracolumbar fractures. Treatment depends on the extent of ligamentous involvement: osseous/Magerl type B2 injuries can be managed conservatively, while ligamentous/Magerl type B1 injuries undergo stabilization with arthrodesis. Minimally invasive surgery without arthrodesis can achieve similar outcomes to open procedures. This has been studied for burst fractures; however, its role in FDI is unclear. To conduct a systematic review of the literature that examined minimally invasive surgery instrumentation without arthrodesis for traumatic FDI of the thoracolumbar spine. Four electronic databases were searched, and articles were screened using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines for patients with traumatic FDI of the thoracolumbar spine treated with percutaneous techniques without arthrodesis and had postoperative follow-up. Seven studies with 44 patients met inclusion criteria. There were 19 patients with osseous FDI and 25 with ligamentous FDI. When reported, patients (n = 39) were neurologically intact preoperatively and at follow-up. Osseous FDI patients underwent instrumentation at 2 levels, while ligamentous injuries at approximately 4 levels. Complication rate was 2.3%. All patients had at least 6 mo of follow-up and demonstrated healing on follow-up imaging. Percutaneous instrumentation without arthrodesis represents a low-risk intermediate between conservative management and open instrumented fusion. This “internal bracing” can be used in osseous and ligamentous FDIs. Neurologically intact patients who do not require decompression and those that may not tolerate or fail conservative management may be candidates. The current level of evidence cannot provide official recommendations and future studies are required to investigate long-term safety and efficacy.

Obliged Removal of the Percutaneous Fixation System on the Thoracolumbar Junction in Patients with Idiopathic Scoliosis

Introduction: Minimally invasive percutaneous surgery of the spine is used to treat thoracolumbar junction and lumbar spine fractures by percutaneous fixation. Once fusion has been obtained, it is possible to remove the percutaneous instrumentation after 6 - 12 months. We report the case of an obliged removal of the fixation system at 12 months following operation in a patient with a pre-existing compensated and asymptomatic idiopathic scoliosis. Case Presentation: A 48-year-old patient affected by a compensated asymptomatic idiopathic scoliosis with an L3 type A3 fracture. The patient underwent a percutaneous short fixation L2 - L4. In the following months the patient presented progressive worsening of the low back pain and walking difficulties. The percutaneous fixation system was then removed using the same surgical access. Conclusions: This particular case explains well the importance of biomechanical balance when a spinal fixation should be perform, and demonstrate how an underestimation of this aspect may cause a worsening of symptoms even if the surgical procedure was correctly performed. It is evident that the removal procedure can lead clinical benefit to a patient, in which the fixation system created a decompensation of the curvature of the spine, thus causing biomechanical alterations and generating pain. In these cases, it may be opportune to limit the fracture reduction during the surgical procedure to modify the least possible the pre-existing scoliosis and to increase the patient’s comfort after the operation. The biomechanical behaviour of the spine is specific for each patient so only a careful detection of it could lead to an optimal therapeutic result.

350 Mini-open Transpedicular Corpectomy and Percutaneous Instrumentation Without Fusion

350 Mini-open Transpedicular Corpectomy and Percutaneous Instrumentation Without Fusion

Besonderheiten der Diagnostik und der minimalinvasiven chirurgischen Behandlung von multiplen Metastasen an der Wirbelsäule durch Plasmafeldtherapie (Cavity-Coblation-Methode)

Background and objectives: Until recently, it was almost impossible to perform major surgery on metastases in the spine. This is especially the case for multiple spinal metastases and for older multi-morbid patients with higher OP risks. It is very important in such cases that the operation should be as minimally invasive as possible, and should aim to reduce pain, treat fractures and to improve the quality of life. The aim of this publication is to present and discuss the specific features of the methodology, problems, surgical techniques, as well as the effectiveness of the modernised cavity/coblation method and results of the treatment of 240 patients with spine metastases. Patients/Material and Method: Patients: Patients of every age with bone destruction were treated, with osteolysis and pathological fractures of vertebrae caused by metastases. The pre-operative diagnosis was evaluated by X-Ray, MRT, CT, whole-body F18-FDG-PET, whole-body bone scintigraphy, histology. Cavity/coblation method: Tumour resection was carried out by the plasma field (42 °C, cold energy) over the percutaneous trans-/extrapedicular access and was followed by balloon kyphoplasty. Tumour tissue was removed, deformation corrected and stability enhanced. The treatment clearly reduced the risks of recurrence, fracture and compression of the neural structures. Local radiotherapy and chemotherapy were performed post-operatively. Clinical and radiological follow-ups, included tumour staging, were performed regularly after the OP (after 2 and 14 days and 3, 6,12, 24, 36, 48 and 60 months), including data on pain and improvement in quality of life. Results: Within 6 years (03/08-04/14), we treated 240 patients with multiple spinal metastases (146 female, 94 male, age range 31-92 years, average age 65.5 years) or 784 vertebral bodies. 61 patients were also given dorsal percutaneous instrumentation and straightening. All patients experienced a significant reduction in pain, and improvements in satisfaction and quality of life. Treatment was combined with chemotherapy and local radiotherapy to reduce tumour cell growth or recurrence rate. Patients could be rapidly mobilised after surgery, blood loss was minimal, and the next oncology treatment could be initiated immediately. Discussion/Conclusions: Cavity/coblation is a safe and minimally invasive procedure, as confirmed by our own short- and long-term results, as well as by reports/publications of other workers. OP risks, blood loss, and surgical time are lower and shorter. This new method is very promising for the future. It is important that the indication is correct and the treatment strategy must be adapted individually. Prognosis must be assessed and the surgical technique must be precise.

Simultaneous Video-Assisted Thoracoscopic Debridement/ Fusion and Percutaneous Transpedicular Instrumentation in Prone Position for Thoracic and Thoracolumbar Infections

Introduction The incidence of vertebral osteomyelitis is reported to range between 2–7% of all cases of bone infection. Spinal infection is age-related and has been on the rise over the last decades. Thus, it occurs frequently in elderly and debilitated patients who have significant medical comorbidities and predisposing factors for spinal infection. The thoracic spine and thoracolumbar junction are areas frequently involved in various types of spinal infections. The aim of surgery in spinal osteomyelitis is to relieve pain by eradication of the infection, reconstruction of the defects and restabilization of the spine. Anterior radical debridement and spinal fusion is advocated as an effective treatment of these infections. Video assisted thoracoscopic surgery (VATS), in cases of thoracic and thoracolumbar spinal infection, is a good alternative to conventional thoracotomy with minimal morbidity, although surgically demanding. There are few reports in the literature of VATS performed on prone patients. This study analyses prospectively 61 patients, who were operated upon for thoracic or thoracolumbar spinal infection in a single tertiary-care referral hospital, between May 2010 and May 2013 using VATS combined with percutaneous fixation in all patients while the patient positioned prone. Material and Methods Between May 2010 and May 2013, 61 patients with spinal infections at the thoracic and thoracolumbar junction were operated upon in our hospital. Those patients underwent anterior thoracoscopically assisted debridement and fusion plus posterior percutaneous stabilization in prone position. The clinical and radiological assessments of these patients were evaluated preoperatively and postoperatively with mean follow up of 37.7 months. The clinical outcomes data were assessed postoperatively and final follow-up by use of VAS and subjective clinical results. Plain X-ray in two views was used for the radiological outcome evaluation. Results Sixty one consecutive patients were included (38 males and 23 females) with mean age of 67.5 years, 78% were older than 60 years. More than 80% of the patients had associated comorbidities. The mean operative time was 195.49 ± 41.60 minutes, for thoracoscopic anterior surgery was 100.57 ±29.14, and for posterior surgery was 94.92 ± 28.35 minutes. The average blood loss was 597.54ml. Thirty two patients (52%) had preoperative neurological deficits ranging from Frankel A to D. One patient (Frankel A) did not show any neurological improvement at the final follow-up. The mean VAS at final follow-up was 1.03/10 (preoperative 7.89). The mean preoperative kyphosis angle was 17.11°, improved to 6.51° postoperatively and reached 8.48° at the final follow-up. First year mortality rate was 6.5% (4 patients). Conclusion Minimal invasive spinal techniques including thoracoscopic debridement and fusion and posterior percutaneous instrumentation showed good clinical and radiological outcomes and can be considered as alternative to open procedures with decreased rates of morbidities in managing thoracic and thoracolumbar infections in elderly patients.

Minimally invasive surgical treatment of tumors and metastases of the spine by plasma field therapy (Cavity-Coblation method)

Background: Tumours and metastases of the spine are extremely stressful for patients. A radical surgery of metastases of the spine is not possible in many cases. Especially higher risk elder multimorbid patients are at risk. The therapeutic goals are always: small invasiveness, high efficiency of tumour removal, fracture repositioning, stabilisation, pain reduction, improving the patient’s life quality. The specialness and difficulties of the diagnosis and therapy with the Cavity/Coblation-method the operative technique, results of the treatment of more than 274 patients with vertebral body tumours/metastases is going to be presented. Materials and methods: Patients: Patients of every age with destruction were treated: with osteolysis, Fractures of the spine caused by spinal tumours and metastases. Diagnosis preoperatively was evaluated through X-Ray, MRT, CT, complete body PET, histology. Cavity/Coblation method: The tumour tissue resection in the vertebra was carried out by the plasma field (T 42C, cold energy) over the percutaneous transpedicular or extrapedicular access and was followed by vertebroplasty or balloon kyphoplasty with PMMA bone cement. This was followed up with clinical and radiological examinations, including data concerning pain and improvement of life quality after 2,14 days as well as 3, 6, 12, 24, 36, 48 and 60 months postoperatively. Results: Within 6 years (03/08-04/14) more than 274 patients (171 female, 103 male, age range of 31-92 y. old average age of 65.7) or 895 vertebral bodies with tumours or metastases were treated. In 61 cases of 274, dorsal percutaneous instrumentation und straightening was an additional treatment. A small amount of blood loss and a very low complication rate was recorded. Postoperatively was shown by all patients an obvious reduction of pain, increase in life quality, satisfaction with the operative result, rapid mobilization was possible as well as the immediate radiation and chemotherapy for reduction of the local tumour recurrence rate. The complications were as follows: in 39 cases of 274 a cement leakage occurred laterally or in the intervertebral disc space without clinical relevance. 194 patients (105 women, 89 men) are now deceased due to tumour manifestations. Conclusions: Coblation/Cavity has shown itself to be a safe, minimal invasive procedure with good short and long term results, a low complication rate, blood loss and short surgery times. The total local recurrence rate for all patients with spine metastases in the study was in 35 from 250 cases/patients with metastasen or only in 14.0%. Following things are important: a comprehensive diagnostic including tumour staging, correct indication, prognostic assessment and precise surgical technique. The method bears much promise for the future.

Mini-open pedicle subtraction osteotomy as a treatment for severe adult spinal deformities: case series with initial clinical and radiographic outcomes.

OBJECTIVE Pedicle subtraction osteotomy (PSO) is a powerful but high-risk surgical technique for destabilizing the spine for deformity correction in both the sagittal and coronal planes. Numerous reports have demonstrated the benefits of this technique for realigning the spine in a physiological posture; however, the open surgical technique is associated with a high complication rate. In this report the authors review data obtained in a series of patients who underwent PSO through a less invasive approach. METHODS Sixteen patients with severe coronal- and/or sagittal-plane deformities were treated in this series. Conservative measures had failed in all cases and patients had undergone a single-level PSO or extended PSO at L-2 or L-3. Fixation was accomplished using percutaneous instrumentation and interbody or facet joint fusions were used at the remaining levels. None of the procedures were aborted or converted to a traditional open procedure. Standard clinical and radiographic measures were used to assess patient outcomes. RESULTS Mean age was 68.8 years and mean follow-up duration was 17.7 months. An average of 7.6 levels were fused, and 50% of the patients had bilateral iliac screw fixation, with all constructs crossing both the thoracolumbar and lumbosacral junctions. Operative time averaged 356 ± 50 minutes and there was a mean blood loss of 843 ± 339 ml. The leg visual analog scale score improved from a mean of 5.7 ± 2.7 to one of 1.3 ± 1.6, and the back visual analog scale score improved from a mean of 8.6 ± 1.3 to one of 2.4 ± 2.1. The Oswestry Disability Index score improved from a mean of 50.1 ± 14.4 to 16.4 ± 12.7, representing a mean reduction of 36.0 ± 16.9 points. The SF-36 physical component summary score changed from a mean of 43.4 ± 2.6 to one of 47.0 ± 4.3, and the SF-36 mental component summary score changed from a mean of 46.7 ± 3.6 to 46.30 ± 3.0. Coronal alignment improved from a mean of 27.9 ± 43.6 mm to 16.0 ± 17.2 mm. The lumbar Cobb angle improved from a mean of 41.2° ± 18.4° to 15.4° ± 9.6°, and lumbar lordosis improved from 23.1° ± 15.9° to 48.6° ± 11.7°. Pelvic tilt improved from a mean of 33.7° ± 8.6° to 24.4° ± 6.5°, and the sagittal vertical axis improved from 102.4 ± 73.4 mm to 42.2 ± 39.9 mm. The final lumbar lordosis-pelvic incidence difference averaged 8.4° ± 12.1°. There were 4 patients who failed to achieve less than or equal to a 10° mismatch on this parameter. Ten of the 16 patients underwent delayed postoperative CT, and 8 of these had developed a solid arthrodesis at all levels treated. A total of 6 complications occurred in this series. There were no cases of symptomatic proximal junction kyphosis. CONCLUSIONS Advancements in minimally invasive technique have resulted in the ability to manage increasingly complex deformities with hybrid approaches. In this limited series, the authors describe the results of utilizing a tissue-sparing mini-open PSO to correct severe spinal deformities. This method was technically feasible in all cases with acceptable radiographic outcomes similar to open surgery. However, high complication rates associated with these deformity corrections remain problematic.

The Importance of Recognizing Diffuse Idiopathic Skeletal Hyperostosis for Neurosurgeons: A Review.

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by calcification and ossification of the soft tissues, mainly ligaments and entheses. The spines of patients with DISH generally become increasingly rigid and osteoporotic, and fractures may occur after even a relatively minor traumatic event such as a ground-level fall. Moreover, the prevalence of DISH may be rapidly increasing in affluent societies. Thus, awareness of this condition is becoming more important for neurosurgeons when assessing trauma patients. For the present article, a literature review was conducted to summarize the current clinical, pathogenetic, and therapeutic knowledge of this disease. Furthermore, current treatment strategies for DISH-related spine injuries are also reviewed. Although the recommended treatment for spinal injuries in DISH patients is surgical, mainly through long-segment posterior fusion, rather than conservative options, stable fractures without any associated neurologic deficits have often been successfully managed with immobilization alone. Percutaneous instrumentation and the use of teriparatide may be useful depending on the surgical risks and patient neurological status.

Stereotactic guidance for navigated percutaneous sacroiliac joint fusion.

Arthrodesis of the sacroiliac joint (SIJ) for surgical treatment of SIJ dysfunction has regained interest among spine specialists. Current techniques described in the literature most often utilize intraoperative fluoroscopy to aid in implant placement; however, image guidance for SIJ fusion may allow for minimally invasive percutaneous instrumentation with more precise implant placement. In the following cases, we performed percutaneous stereotactic navigated sacroiliac instrumentation using O-arm® multidimensional surgical imaging with StealthStation® navigation (Medtronic, Inc. Minneapolis, MN). Patients were positioned prone and an image-guidance reference frame was placed contralateral to the surgical site. O-arm® integrated with StealthStation® allowed immediate auto-registration. The skin incision was planned with an image-guidance probe. An image-guided awl, drill and tap were utilized to choose a starting point and trajectory. Threaded titanium cage(s) packed with autograft and/or allograft were then placed. O-arm® image-guidance allowed for implant placement in the SIJ with a small skin incision. However, we could not track the cage depth position with our current system, and in one patient, the SIJ cage had to be revised secondary to the anterior breach of sacrum.

Minimal Invasive Circumferential Management of Thoracolumbar Spine Fractures.

Introduction. While thoracolumbar fractures are common lesions, no strong consensus is available at the moment. Objectives. The aim of this study was to evaluate the results of a minimal invasive strategy using percutaneous instrumentation and anterior approach in the management of thoracolumbar unstable fractures. Methods. 39 patients were included in this retrospective study. Radiologic evaluation was based on vertebral and regional kyphosis, vertebral body height restoration, and fusion rate. Clinical evaluation was based on Visual Analogic Score (VAS). All evaluations were done preoperatively and at 1-year follow-up. Results. Both vertebral and regional kyphoses were significantly improved on postoperative evaluation (13° and 7° versus −1° and −9° P < 0.05, resp.) as well as vertebral body height (0.92 versus 1.16, P < 0.05). At 1-year follow-up, mean loss of correction was 1°. A solid fusion was visible in all the cases, and mean VAS was significantly reduced form 8/10 preoperatively to 1/10 at the last follow-up. Conclusion. Management of thoracolumbar fractures using percutaneous osteosynthesis and minimal invasive anterior approach (telescopic vertebral body prosthesis) is a valuable strategy. Results of this strategy offer satisfactory and stable results in time.

Simultaneous Lateral Interbody Fusion and Posterior Percutaneous Instrumentation: Early Experience and Technical Considerations.

Lumbar fusion surgery involving lateral lumbar interbody graft insertion with posterior instrumentation is traditionally performed in two stages requiring repositioning. We describe a novel technique to complete the circumferential procedure simultaneously without patient repositioning. Twenty patients diagnosed with worsening back pain with/without radiculopathy who failed exhaustive conservative management were retrospectively reviewed. Ten patients with both procedures simultaneously from a single lateral approach and 10 control patients with lateral lumbar interbody fusion followed by repositioning and posterior percutaneous instrumentation were analyzed. Pars fractures, mobile grade 2 spondylolisthesis, and severe one-level degenerative disk disease were matched between the two groups. In the simultaneous group, avoiding repositioning leads to lower mean operative times: 130 minutes (versus control 190 minutes; p = 0.009) and lower intraoperative blood loss: 108 mL (versus 93 mL; NS). Nonrepositioned patients were hospitalized for an average of 4.1 days (versus 3.8 days; NS). There was one complication in the control group requiring screw revision. Lateral interbody fusion and percutaneous posterior instrumentation are both readily accomplished in a single lateral decubitus position. In select patients with adequately sized pedicles, performing simultaneous procedures decreases operative time over sequential repositioning. Patient outcomes were excellent in the simultaneous group and comparable to procedures done sequentially.

Réduction et fixation percutanée par voie postérieure des fractures thoracolombaires de type « burst » (éclatement)

BackgroundTreatment of A3 thoracolumbar and lumbar spinal fractures nowadays remains a controversial issue. Percutaneous techniques are becoming very popular in the last few years to reduce the approach-related morbidity associated with conventional techniques. HypothesisPurpose of the study was to analyze the clinical and radiological outcome of patients who underwent percutaneous posterior fixation without fusion for the treatment of thoracolumbar and lumbar A3 fractures. Materials and methodsSixty-three patients, having sustained a single-level thoracolumbar fracture, underwent short segment percutaneous instrumentation and were retrospectively analyzed way. Sagittal Index (SI) was calculated in all patients. Clinical and functional outcome were evaluated by Visual Analog Scale (VAS), Oswestry Disability Index (ODI) and Short Form General Health Status (SF-36). ResultsAverage operative blood loss was 82mL (50–320). Mean pre-operative SI in the thoraco-lumbar segment was 13.3° decreased to 5.8° in the immediate post-operative with a mean deformity correction of 7.5. Mean pre-operative SI in the lumbar segment was 16.5° decreased to 11.3° in the immediate post-operative with a mean deformity correction of 5.2. Not statistically significant correction loss was registered at 1year minimum follow-up. Constant clinical conditions improvement in the examined patients was observed. ConclusionPercutaneous pedicle screw fixation for A3 thoracolumbar and lumbar spinal fractures is a reliable and safe procedure. Level of evidenceLevel IV. Retrospective study.

Use of anteroposterior view fluoroscopy for targeting percutaneous pedicle screws in cases of spinal deformity with axial rotation.

Over the past decade percutaneous pedicle screws have become popular for the minimally invasive treatment of spinal disorders. However, until the last 5 years the presence of a significant spinal deformity was regarded as a relative contraindication for percutaneous instrumentation. Recent advances in surgical technique and intraoperative technology have made percutaneous fixation in complex spinal pathologies more commonplace. The authors report their experience using a parsimonious method for uniplanar fluoroscopic targeting of pedicles in challenging cases. The authors performed a retrospective analysis of patients with adult spinal deformity who underwent percutaneous pedicle screw instrumentation from 2008 to 2013. Cases were included if a spiral slice postoperative CT scan was obtained. All cases had a minimum of 10° of axial rotation and typically had additional accompanying anatomical abnormalities. Screws were assessed for any pedicle violations as well as any impingement of the surrounding facet joints. A total of 410 pedicle screws were placed in 36 patients with an average 6.4 levels of instrumentation per patient. The mean age was 67 years (range 44-86 years) and there were 25 females. Of the 410 screws, 29 (7.1%) had some medial or lateral pedicle violation. Of these, 15 (3.7%) were Grade 1, 6 (1.4%) were Grade 2, and 8 (2.0%) were Grade 3 violations. Of the Grade 3 violations, 2 each were at the L-4, L-5, and S-1 levels, and 1 each was at the T-10 and L-1 levels. Two of the patients had symptoms and both underwent screw repositioning, one during the same admission and the other in a delayed fashion. Both were at the L-5 and S-1 levels with anatomically highly medialized pedicles. There were no motor deficits, and both removals were for numbness. Of the 72 screws at the proximal end of the construct, there were 6 facet violations (8.3%). Four (5.6%) of these were Grade 1, 1 (1.4%) was Grade 2, and 1 (1.4%) was Grade 3. The anteroposterior fluoroscopic technique can be effectively used by spinal surgeons to cannulate the pedicles in patients with rotational deformities. The complication rate in this challenging population is acceptable and is in accordance with the existing literature. However, caution should be used at L-5 and S-1 when the pedicle is narrow and highly medialized, rendering an indistinct medial wall on anteroposterior imaging.

Posterior percutaneous reduction and fixation of thoraco-lumbar burst fractures

BackgroundTreatment of A3 thoraco-lumbar and lumbar spinal fractures nowadays remains a controversial issue. Percutaneous techniques are becoming very popular in the last few years to reduce the approach-related morbidity associated with conventional techniques. HypothesisPurpose of the study was to analyze the clinical and radiological outcome of patients who underwent percutaneous posterior fixation without fusion for the treatment of thoraco-lumbar and lumbar A3 fractures. Materials and methodsSixty-three patients, having sustained a single-level thoraco-lumbar fracture, underwent short segment percutaneous instrumentation and were retrospectively analyzed. sagittal index (SI) was calculated in all patients. Clinical and functional outcome were evaluated by Visual Analog Scale (VAS), Oswestry Disability Index (ODI) and Short Form General Health Status (SF-36). ResultsAverage operative blood loss was 82mL (50–320). Mean pre-operative SI in the thoraco-lumbar segment was 13.3° decreased to 5.8° in the immediate postoperative with a mean deformity correction of 7.5. Mean pre-operative SI in the lumbar segment was 16.5° decreased to 11.3° in the immediate postoperative with a mean deformity correction of 5.2. Not statistically significant correction loss was registered at 1-year minimum follow-up. Constant clinical conditions improvement in the examined patients was observed. ConclusionPercutaneous pedicle screw fixation for A3 thoraco-lumbar and lumbar spinal fractures is a reliable and safe procedure. Level of evidenceLevel IV. Retrospective study.

What is the Rate of Lumbar Adjacent Segment Disease after Percutaneous versus Open Fusion?

Adjacent segment disease (ASD) requiring treatment or re-operation is a common problem after surgery on the lumbar spine. The hypothesis of this retrospective study was that ASD occurs less often following lumbar spine fusion in patients who undergo percutaneous minimally invasive (MIS) instrumentation than in those in whom open instrumentation is used. A case-control study was performed on consecutive patients who had undergone staged single or two level anterior lumbar interbody fusion for degenerative conditions followed by open or MIS instrumentation from 2002 to 2005 in our institution. ASD was defined as that necessitating additional procedures for new symptoms related to an adjacent lumbar dermatome. One hundred and seventeen patients met the inclusion criteria. Of these, 53 had been followed up by chart or medical record review for longer than one year. There were 23 patients in the MIS group and 30 in the open group. Of the 30 patients in the open group, 9 had developed ASD (30%). Of the 23 patients in the MIS group, 7 had developed ASD (30%). This difference is not statistically significant (P = 1.00). Contrary to our hypothesis, there was no significant difference in incidence of ASD in patients who had underwent open versus percutaneous instrumentation following anterior lumbar interbody fusion.

Editorial: Sagittal balance

It has become increasingly clear in the past decade that local, regional, and global sagittal alignment of the spinal column is strongly correlated to both quality of life assessments and also the results of spinal surgical interventions. Traditional open spinal reconstructive procedures have emphasized these sagittal parameters recently, correlating to successful radiographic and clinical results. However, the quest for similar type of results when using less invasive surgical techniques has been more challenging. In their article, Manwaring and colleagues1 performed a preliminary radiographic study examining the role that minimally invasive anterolateral lumbar interbody fusion plays in optimizing lumbar sagittal lordosis restoration, global sagittal alignment, and ultimately clinical outcomes. In their retrospective review, data obtained in 36 patients in whom degenerative scoliosis had been diagnosed (coronal Cobb angle of > 10° or a sagittal vertebral axis of > 5 cm) were examined for various coronal and sagittal radiographic parameters. Of 36 patients, 27 had undergone standard anterolateral interbody fusion and 9 had undergone an anterior column release (ACR) with interbody fusion. In all patients a delayed second-stage surgery was performed and consisted of the placement of percutaneous transpedicular posterior instrumentation as well as an anterolateral lumbar interbody fusion or minimally invasive transforaminal lumbar interbody fusion at L5–S1 if that was included in the construct. The authors found, as others have shown, that a standard lateral interbody fusion really did not change segmental and regional lumbar lordosis, although it did improve the coronal Cobb angle. However, the ACR group had significant improvements in segmental and regional lumbar lordosis and sagittal realignment as well as improvement in the coronal Cobb angle. Unfortunately, there were no data provided on complications occurring during or after the procedure, and the mean follow-up for the small ACR group was admittedly short in the preliminary study (11 months). So what can we learn from this preliminary radiographic analysis of these less invasive surgical techniques? In patients with relatively small degenerative lumbar scoliosis (mean coronal curves, 25°), the ACR technique can increase segmental and regional lordosis, which is certainly an important component to the surgical goals and ultimate clinical outcomes. The addition of posterior segmental percutaneous instrumentation did not seem to change the alignment or results, which is intuitive since correction was obtained with the anterior interbody procedure. This is certainly an important finding in the evolution of less invasive spinal surgical reconstructive techniques. However, it is important to note that there are things we did not learn from this radiographic review, including the following: the actual or potential complications from the ACR technique, durability of the radiographic results because the follow-up period was so short, ultimate fusion rates, and clinical outcomes at a minimum 2to 5-year follow-up. Also, whether these results can be replicated at other centers is yet to be determined. I congratulate the authors on this important manuscript and urge them to continue to pursue and publish additional data on complications and longer-term followup in the degenerative lumbar scoliosis population treated with these less invasive surgical techniques. (http://thejns.org/doi/abs/10.3171/2013.10.SPINE13793)

Percutaneous dorsal instrumentation for thoracolumbar extension-distraction fractures in patients with ankylosing spinal disorders: a case series

Background contextThoracolumbar extension-distraction fractures are rare injuries mainly restricted to patients suffering from ankylosing spinal disorders. The most appropriate surgical treatment of these unstable spinal injuries remains to be clarified. PurposeTo report on a cohort of 10 patients treated with closed reduction and percutaneous dorsal instrumentation. Study designCase series. Patient sampleTen consecutive patients with ankylosing spinal disorders and thoracolumbar extension-distraction fractures (Type B3 according to the AOSpine Thoracolumbar Spine Injury Classification System). Outcome measuresPostoperative reduction, alignment, and implant position were analyzed by computed tomography. Loss of reduction was assessed on lateral radiographs by using the Cobb technique. Ambulation ability and pain were assessed at follow-up. MethodsMinimally invasive dorsal percutaneous instrumentation was performed in 10 consecutive patients (3 men, 7 women) with a mean age of 81.5 (range 72–90) years between May 2010 and December 2012. The mean postoperative follow-up time was 7.9 (range 4–28) months. ResultsAll 10 patients were treated with closed reduction and dorsal instrumentation; in no case was conversion to an open approach required. The mean operation time was 60.2 (range 32–135) minutes. None of the patients presented neurologic deficits. Cement-augmented screws were implanted in two cases. Sufficient radiographic correction was achieved in all patients; no case of loss of reduction was noted at final follow-up. In one case, complete hardware removal was performed 9 months after the index operation because of persistent back pain at the level of the implant. One patient died of postoperative inferior vena cava obstruction. At discharge, all patients were able to ambulate without the need for crutches or opioid analgesics. At final follow-up, all patients ambulated with full weight bearing; four patients reported persistent back pain. ConclusionsIn fragile patients with ankylosing spinal disorders and thoracolumbar extension-distraction fractures, closed reduction and percutaneous dorsal instrumentation provide a satisfying midterm functional outcome while minimizing perioperative risks compared with conventional dorsoventral procedures.