Video-assisted thoracoscopic treatment of spinal lesions in the thoracolumbar junction

The Thoracoscopic Approach in Spinal Cord Disease

Video-assisted thoracic surgery (VATS) has been growing in popularity over the past 2 decades as an alternative to open thoracotomy for the treatment of several spinal conditions, and in the field of minimally invasive surgery, it now acts as a keyhole to the thoracic spine.

MATERIALS AND METHODS

Most VATS approaches are from the right side for pathologies involving the middle and upper thoracic spine because there is a greater working spinal surface area lateral to the azygos vein than that lateral to the aorta. Below T-9, a left-sided approach is made possible because the aorta moves away from the left posterolateral aspect of the spine to an anterior position as it passes through the diaphragm.

RESULTS

VATS has been used extensively in spinal deformities such as scoliosis. The use of VATS in spine surgery includes the treatment of thoracic prolapsed disk diseases, vertebral osteomyelitis, fracture management, vertebral interbody fusion, tissue biopsy, anterior spinal release, and fusion without or with instrumentation (VAT-I) for spinal deformity correction. As the knowledge and the comfort of using such techniques have expanded, the indications have extended to corpectomy for tumor resections.

DISCUSSION AND CONCLUSIONS

In the field of minimally invasive surgery, VATS now acts as a keyhole to the thoracic spine and an alternative to open thoracotomy for the treatment of several spinal conditions.Although VATS can be performed in such spine conditions, it is most beneficial in the treatment of scoliotic deformity, which requires taking a multilevel approach, from the upper to the lower thoracic spine.

Video-Assisted Thoracoscopic Surgery and Minimal Access Spinal Surgery Compared in Anterior Thoracic or Thoracolumbar Junctional Spinal Reconstruction: A Case-Control Study and Review of the Literature

There are no published reports that compare the outcomes of video-assisted thoracoscopic surgery (VATS) and minimal access spinal surgery (MASS) in anterior spinal reconstruction. We conducted a retrospective case-control study in a single center and systematically reviewed the literature to compare the efficacy and safety of VATS and MASS in anterior thoracic (T) and thoracolumbar junctional (TLJ) spinal reconstruction. From 1995 to 2012, there were 111 VATS patients and 76 MASS patients treated at our hospital. VATS patients had significantly (p < 0.001) longer operating times and significantly (p < 0.022) higher thoracotomy conversion rates. We reviewed 6 VATS articles and 10 MASS articles, in which there were 625 VATS patients and 399 MASS patients. We recorded clinical complications and a thoracotomy conversion rate from our cases and the selected articles. The incidence of approach-related complications was significantly (p = 0.021) higher in VATS patients. The conversion rate was 2% in VATS patients and 0% in MASS patients (p = 0.001). In conclusion, MASS is associated with reduction in operating time, approach-related complications, and the thoracotomy conversion rate.

When Less Is More: The indications for MIS Techniques and Separation Surgery in Metastatic Spine Disease

STUDY DESIGN

Systematic review.

OBJECTIVE

The aim of this study was to review the techniques, indications, and outcomes of minimally invasive surgery (MIS) and separation surgery with subsequent radiosurgery in the treatment of patients with metastatic spine disease.

SUMMARY OF BACKGROUND DATA

The utilization of MIS techniques in patients with spine metastases is a growing area within spinal oncology. Separation surgery represents a novel paradigm where radiosurgery provides long-term control after tumor is surgically separated from the neural elements.

METHODS

PubMed, Embase, and CINAHL databases were systematically queried for literature reporting MIS techniques or separation surgery in patients with metastatic spine disease. PRISMA guidelines were followed.

RESULTS

Of the initial 983 articles found, 29 met inclusion criteria. Twenty-five articles discussed MIS techniques and were grouped according to the primary objective: percutaneous stabilization (8), tubular retractors (4), mini-open approach (8), and thoracoscopy/endoscopy (5). The remaining 4 studies reported separation surgery. Indications were similar across all studies and included patients with instability, refractory pain, or neurologic compromise. Intraoperative variables, outcomes, and complications were similar in MIS studies compared to traditional approaches, and some MIS studies showed a statistically significant improvement in outcomes. Studies of mini-open techniques had the strongest evidence for superiority.

CONCLUSIONS

Low-quality evidence currently exists for MIS techniques and separation surgery in the treatment of metastatic spine disease. Given the early promising results, the next iteration of research should include higher-quality studies with sufficient power, and will be able to provide higher-level evidence on the outcomes of MIS approaches and separation surgery.

LEVEL OF EVIDENCE

N/A.

Comparison of minimal access and traditional anterior spinal surgery in managing infectious spondylitis: a minimum 2-year follow-up

BACKGROUND CONTEXT

Traditional anterior spinal surgery (TASS) for the thoracolumbar spine is associated with significant morbidities. To avoid excessive tissue damage, minimal access spinal surgery (MASS) has been developed to treat a variety of anterior spinal disorders at the authors' institution. No previous reports comparing the outcomes of MASS and TASS for the treatment of infectious spondylitis were noted in the literature, to our knowledge.

PURPOSE

The aim of this study was to investigate the outcomes of MASS in managing infectious spondylitis and compare the results to TASS with a minimum follow-up of 2 years.

STUDY DESIGN

A retrospective comparative cohort study in a single center.

PATIENT SAMPLE

Forty patients with thoracic or lumbar infectious spondylitis who underwent anterior spinal surgery were enrolled.

OUTCOME MEASURES

Perioperative data including operative time, estimated blood loss, packed red blood cell transfusion, postoperative tube drainage, need for intensive care, and length of hospital stay. Postoperative complications were classified according to the Clavien-Dindo system. Fusion grade was assessed by plain radiographs on the basis of Burkus criteria.

METHODS

Between January 2002 and June 2010, all enrolled patients were collected via the Spine Operation Registry of the authors' institution. There were 23 MASS patients and 17 TASS patients. The average follow-up was 4.2 years (range, 2-9 years).

RESULTS

The mean estimated blood loss in MASS and TASS groups was 521.7 versus 979.4 mL (p=.007), intraoperative transfusion of packed red blood cells was 0.9 versus 2.7 units (p=.019), the amount of postoperative tube drainage was 235.2 versus 454.3 mL (p=.005), the number of patients requiring postoperative intensive care was 2 versus 7 (p=.023), and length of hospital stay was 15.4 versus 22.9, respectively (p=.043). The overall complication rate in the MASS group was 17% and 59% in the TASS group (p=.007). No major complications occurred in the MASS group, whereas four occurred in the TASS group (p=.026). Bone graft union was achieved in 38 of 39 survival patients (97%), with no difference between the groups. One patient in TASS had a pseudarthrosis and needed a posterior instrumented fusion.

CONCLUSIONS

Minimal access spinal surgery has been suggested to be an effective and safe technique in treating thoracic and lumbar infectious spondylitis. Minimal access spinal surgery did not need endoscopic equipments or complex surgical instruments. Furthermore, in comparison to TASS, MASS resulted in a reduced blood transfusion amount, decreased intensive care unit stay, reduced overall length of stay, and reduced surgical complication rate. Nevertheless, the risks may be increased in performing MASS on patients with multilevel involvement, which could be associated with high vascularity, alternated vascular anatomy, increased soft-tissue edema, and adhesion.

Robot-assisted triple neurectomy for iatrogenic inguinal pain: a technical note

BACKGROUND

Painful neuromas are a relatively common complication of hernia and abdominal wall surgery.

OBJECTIVE

Surgical neurectomy has the potential to to provide durable relief for chronic pain; however, current surgical approaches are not without morbidity or anatomical challenges.We sought a surgical alternative.

METHODS

In the treatment of a case of incapacitating inguinal pain, we performed an anterior transperitoneal approach using a surgical robot.

RESULTS

This approach was facile and provided elegant anatomical visualization.

CONCLUSION

This case describes the first known robot-assisted laparoscopic triple neurectomy and details a simplified, transperitoneal approach.

Vertebral body cage use in thoracolumbar fractures: outcomes in a prospective series of 23 cases at 2 years' follow-up

INTRODUCTION

One objective of surgery in thoracolumbar spine fracture is to restore correct and lasting spinal statics. This may involve vertebral body replacement using an anterior approach. We here report results on a prospective series of 23 trauma patients managed by vertebral body replacement using an expandable cage.

PATIENTS AND METHODS

The sex ratio was 2.28. Fifteen cases involved primary treatment of recent fracture and eight secondary surgery for non-union or malunion. In 12 cases, posterior osteosynthesis was associated. Six patients were operated on using a classical approach and 17 using a video-assisted minimally invasive approach. Pre- and perioperative data were recorded, with clinical scores (VAS and Oswestry) at 6 weeks, 3 months, 6 months, 1 year and 2 years. Radiologic follow-up assessed regional traumatic kyphosis (RTK), enabling calculation of regional traumatic angulation (RTA), with control CT to check fusion.

RESULTS

Minimum follow-up was 2 years. There were no cases of postoperative neurological deterioration. There were three major postoperative complications: one hemothorax, one adhesive bowel occlusion, and one bilateral pneumothorax at 1 month. Mean Oswestry score at 6 months was 20%, and mean VAS score at 2 years was 0.36. Postoperative RTA showed a mean 7.34° improvement. Mean RTA reduction loss was 1.95° at 3 months, subsequently unchanged. All arthrodeses showed fusion at 6 months.

CONCLUSION

Results were satisfactory with this technique, comparable to those reported in the literature. The development of minimally invasive approaches and improved instrumentation procedures optimize surgery and enhance anterior reconstruction tolerance. Lasting restoration of sagittal spinal curvature improves trauma patients' functional recovery.

Metastatic spine disease in the elderly: diagnostic and management considerations

Metastatic spine disease is becoming a more frequent problem in cancer patients as advancements in treatment for primary tumors prolong patient survival. Elderly patients over 60 years of age make up the majority of these cases, with the incidence of metastatic disease several folds higher in the elderly than in any other age group. These patients are also the most challenging group to treat, given higher rates of comorbidities and decreased tolerance to medical, surgical and radiation therapies. Advancements in therapeutic strategies, including minimally invasive surgeries and stereotactic radiosurgery, have provided increasingly attractive treatment options for elderly patients owing to their decreased procedure-associated morbidity. This article will discuss efficacy and limitations of conventional, as well as more recent, treatment modalities with an emphasis on their role in the management of elderly patients.

Minimally invasive management of spinal metastases

In most patients who have spinal metastases, treatment is mainly palliative. The conventional surgical methods carry higher risks of complications and postoperative morbidity. Minimally invasive spinal interventions seem to be reasonable alternatives to treat spinal metastatic disease. These procedures can result in less soft tissue trauma, lower blood loss, shorter hospitalization time and are better tolerated by the patients. In this review, the techniques and results of minimally invasive management in spinal metastasis, including percutaneous image-guided interventions (vertebroplasty, kyphoplasty, and radiofrequency ablation) and minimally invasive surgical techniques (endoscopic and minimal access operations), are presented.

Minimally invasive posterior thoracic fusion

Thoracic spine fusion may be indicated in the surgical treatment of a wide range of pathologies, including trauma, deformity, tumor, and infection. Conventional open procedures for surgical treatment of thoracic spine disease can be associated with significant approach-related morbidity, which has motivated the development of minimally invasive approaches. Thoracoscopy and, later, video-assisted thoracoscopic surgery were developed to address diseases of the thoracic cavity and subsequently adapted for thoracic spine surgery. Although video-assisted thoracoscopic surgery has been used to treat a variety of thoracic spine diseases, its relatively steep learning curve and high rate of pulmonary complications have limited its widespread use. These limitations have motivated the development of minimally invasive posterior approaches to address thoracic spine pathology without the added risk of morbidity involved in surgically entering the chest. Many of these advances are ongoing and represent the forefront of minimally invasive spine surgery. As these techniques are developed and applied, it will be important to assess their equivalence or superiority in comparison with standard open techniques using prospective trials. In this paper the authors focus on minimally invasive posterior thoracic procedures that include fusion, and provide a review of the current literature, a discussion of future pathways for development, and case examples. The topic is divided by pathology into sections including trauma, deformity, spinal column tumors, and osteomyelitis.

Clinical study of a new approach to thoracolumbar surgery

OBJECTIVE

The conventional approaches for treatment of thoracolumbar diseases require extensive surgical exposure, often leading to postoperative pain and morbidity. Thoracoscopic-assisted surgery in these regions usually requires an extended recovery period due to the placement of drainage. We developed an innovative retroperitoneal-extrapleural approach to thoracolumbar involvement by an extra-diaphragmatic technique using dedicated instruments. Neither incision nor reconstruction of the diaphragm was necessary. Exposure to the lateral part of the thoracolumbar vertebrae could be achieved without crus resection. This study is aimed to evaluate the clinical outcomes of this new surgical procedure.

METHODS

A total of 9 cases (5 cases of thoracolumbar fracture-dislocation, 1 each of spinal infection, tumor, thoracolumbar scoliosis and ossification of posterior longitudinal ligament) were subjected to the study. The average age of the patients was 52.3 years. The results were compared with the control group consisting of thoracoscopic surgery subgroup (5 patients, mean age 52.1 years) and conventional surgery subgroup (12 patients, mean age 61.3 years).

RESULTS

Compared with the control group, the average period of bed confinement and mean intra- and postoperative blood loss decreased significantly. Pulmonary complications were avoided in all cases. The surgical time was shortened, postoperative pain was reduced, and early postoperative ambulation became possible.

CONCLUSION

The diaphragm-preserving retroperitoneal-extrapleural approach that we developed is a valid minimally invasive alternative for the treatment of thoracolumbar diseases.

Clinical Analysis of Video-assisted Thoracoscopic Spinal Surgery in the Thoracic or Thoracolumbar Spinal Pathologies

OBJECTIVE

Thoracoscopic spinal surgery provides minimally invasive approaches for effective vertebral decompression and reconstruction of the thoracic and thoracolumbar spine, while surgery related morbidity can be significantly lowered. This study analyzes clinical results of thoracoscopic spinal surgery performed at our institute.

METHODS

Twenty consecutive patients underwent video-assisted thoracosopic surgery (VATS) to treat various thoracic and thoracolumbar pathologies from April 2000 to July 2006. The lesions consisted of spinal trauma (13 cases), thoracic disc herniation (4 cases), tuberculous spondylitis (1 case), post-operative thoracolumbar kyphosis (1 case) and thoracic tumor (1 case). The level of operation included upper thoracic lesions (3 cases), midthoracic lesions (6 cases) and thoracolumbar lesions (11 cases). We classified the procedure into three groups: stand-alone thoracoscopic discectomy (3 cases), thoracoscopic fusion (11 cases) and video assisted mini-thoracotomy (6 cases).

RESULTS

Analysis on the Frankel performance scale in spinal trauma patients (13 cases), showed a total of 7 patients who had neurological impairment preoperatively : Grade D (2 cases), Grade C (2 cases), Grade B (1 case), and Grade A (2 cases). Four patients were neurologically improved postoperatively, two patients were improved from C to E, one improved from grade D to E and one improved from grade B to grade D. The preoperative Cobb's and kyphotic angle were measured in spinal trauma patients and were 18.9+/-4.4 degrees and 18.8+/-4.6 degrees , respectively. Postoperatively, the angles showed statistically significant improvement, 15.1+/-3.7 degrees and 11.3+/-2.4 degrees , respectively (P<0.001).

CONCLUSION

Although VATS requires a steep learning curve, it is an effective and minimally invasive procedure which provides biomechanical stability in terms of anterior column decompression and reconstruction for anterior load bearing, and preservation of intercostal muscles and diaphragm.

Techniques for the operative management of thoracic disc herniation: minimally invasive thoracic microdiscectomy

Thoracic disc herniations are uncommon lesions that are asymptomatic in most patients; however, for individuals who present with persistent radiculopathy that is nonresponsive to conservative treatment or with myelopathic symptoms with or without radiculopathy attributed to a thoracic disc herniation, operative intervention of the thoracic spine is sought. Various procedures and approaches for the treatment of thoracic disc herniations have been reported, but they have been associated with numerous intraoperative complications and postoperative morbidities. This article discusses a novel minimally invasive procedure for the surgical treatment of thoracic disc herniations referred to as a minimally invasive thoracic microdiscectomy. It uses a series of muscle dilators, a tubular retractor, and microscopic visualization by way of a posterolateral approach in an effort to minimize many of the complications that are associated with the more traditional approaches.

Influence of screw-cement enhancement on the stability of anterior thoracolumbar fracture stabilization with circumferential instability

The influence of additional dorsal structure damage on anterior stabilization of a thoracolumbar fracture is still unknown. Screw-cement enhancement can be used to reinforce the stability of anterior instrumentation. We have developed a new anchorage system for fixation of anterior stabilization devices, adapted through geometric optimization and the additional option of cementation after screw insertion. This study examines the question of whether this enhancement is strong enough to enable a single anterior procedure and still compensate for dorsal instability. Various spinal reconstruction procedures were evaluated biomechanically in an increasing ventrodorsal instability model for thoracolumbar fracture stabilization. A biomechanical in vitro study, simulating stabilized defect situations (corporectomy/vertebrectomy) with strut grafting and overbridging instrumentation, was performed on six human T10-L2 cadaveric specimens. The primary stability parameters, range of motion and neutral zone, were evaluated with or without anterior screw-cement enhancement. This was compared with a single conventional anterior stabilization without a dorsal defect (corporectomy). It was also compared with a single anterior, posterior or combined procedure in the presence of additional dorsal structure damage (vertebrectomy). The use of an additional cementable screw dowel enhanced the primary stability of the anterior instrumentation, compensating for dorsal instability. These results are warranted for the clinical use of minimally open or endoscopic techniques, creating the highest possible primary stability while performing a single anterior enhanced instrumentation with a tissue-preserving approach.

Thoracic microendoscopic discectomy

OBJECT

Various approaches exist for the treatment of thoracic disc herniation. Anterior approaches facilitate ventral exposure but place the intrathoracic contents at risk. Posterolateral approaches require extensive muscle dissection that adds to the risk of postoperative morbidity. The authors have developed a novel posterolateral, minimally invasive thoracic microendoscopic discectomy (TMED) technique that provides an approach to the thoracic spine which is associated with less morbidity.

METHODS

Seven patients 23 to 54 years old with nine disc herniations underwent TMED. All lesions were soft lateral or midline thoracic disc herniations. Under fluoroscopic guidance with the patient positioned prone, the authors used a muscle dilation approach and the procedure was performed with endoscopic visualization through a tubular retractor. Based on a modified Prolo Scale, five patients experienced excellent results, one good, and one fair. No case required conversion to an open procedure. The mean operative time was 1.7 hours per level, and estimated blood loss was 111 ml per level. Hospital stays were short, and no complications occurred.

CONCLUSIONS

The TMED is safe, effective, and provides a minimally invasive posterolateral alternative for treatment of thoracic disc herniation without the morbidity associated with traditional approaches.

Solvent-preserved, bovine cancellous bone blocks used for reconstruction of thoracolumbar fractures in minimally invasive spinal surgery-first clinical results

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively. Solvent-preserved, bovine cancellous bone blocks were used in 11 patients; iliac crest bone graft was used in the others. Follow-up after 12 months included CT scans, which revealed successful osseointegration in eight out of 11 patients who had received autogenous iliac crest bone grafts, while three patients showed a partial integration. There were no graft fragmentations. In patients who had received solvent-preserved, xenogenous cancellous bone blocks, complete osseointegration was achieved at the graft-bone interface in only two out of 11 cases, after 1 year. Partial integration was found in three patients. In view of these results, autogenous iliac crest bone grafts are still the unrivalled standard for defect repair in spinal surgery.

Thoracoscopic transdiaphragmatic approach to thoracolumbar junction fractures

BACKGROUND CONTEXT

Anterior approaches to the thoracocolmbar junction (TLJ) are often required to restore anterior column deficiency after spinal trauma. Conventional open approaches are often associated with significant morbidity, and hence there is a need for a minimally invasive approach to TLJ fractures.

PURPOSE

To report the feasibility and effectiveness of the thoracoscopic transdiaphragmatic approach (TTA) in the management of TLJ fractures.

STUDY DESIGN

A retrospective analysis of 212 patients undergoing surgery at two institutions by the TTA with neurological outcomes, fusion rates and complications.

PATIENT SAMPLE

This is a two-institution study of 212 patients managed by TTA, from Berufsgenossenschaftliche Unfallklinik Marnau, a regional trauma facility located in Murnau, Bavaria, Germany, and from Stanford University, Stanford, California from May 1996 to June 2002. Patient ages ranged from 16 to 75 years (mean, 36 years) and included 158 males and 62 females.

OUTCOME MEASURES

The neurological status was assessed by the Frankel Neurological Performance scale pre- and postoperatively. Plain radiographs obtained 1 year postoperatively assessed fusion radiologically.

METHODS

All patients underwent spinal decompression, reconstruction and instrumentation by the TTA. Seventy-five patients had anterior instrumentation alone, whereas the remaining 137 had combined anterior and posterior instrumentation. A Z-Plate was used for spinal instrumentation from May 1996 to October 1999 and the MACS-TL system from November 1999 to June 2002.

RESULTS

Monosegmental, bisegmental and multisegmental fixations were used in 46%, 48% and 6% of cases, respectively. Follow-up ranged from 12 months to 6 years (mean, 3.9 years). Surgical durations ranged between 70 minutes and 7 hours (mean, 3.5 hours). Successful bony fusion with maintenance of satisfactory spinal alignment was observed in approximately 90% of our patients. Anterior screw loosening was seen in five cases (2.4%), four involving the Z-Plate system and the other involving the MACS-TL system. Three patients (1.4%) required conversion to an open procedure. Access-related complications, such as pleural effusion, pneumothorax and intercostal neuralgia, were seen in 12 patients (5.7%). Three patients (1.4%) had superficial portal infections. We encountered no diaphragmatic herniations.

CONCLUSIONS

TTA provides excellent access to the entire TLJ, permitting satisfactory spinal decompression, reconstruction and instrumentation. Diaphragmatic opening and repair can be accomplished safely and effectively without special endoscopic instrumentation. It also precludes the need for retroperitoneoscopic or open thoracoabdominal approaches and thus avoids the associated significant morbidity.

Thoracolumbar fracture stabilization: comparative biomechanical evaluation of a new video-assisted implantable system

Minimally invasive techniques for spinal surgery are becoming more widespread as improved technologies are developed. Stabilization plays an important role in fracture treatment, but appropriate instrumentation systems for endoscopic circumstances are lacking. Therefore a new thoracoscopically implantable stabilization system for thoracolumbar fracture treatment was developed and its biomechanical in vitro properties were compared. In a biomechanical in vitro study, burst fracture stabilization was simulated and anterior short fixation devices were tested under load with pure moments to evaluate the biomechanical stabilizing characteristics of the new system in comparison with a currently available system. With interbody graft and fixation the new system demonstrated higher stabilizing effects in flexion/extension and lateral bending and restored axial stability beyond the intact spine, as well as having comparable or improved effects compared with the current system. Because of this biomechanical characterization a clinical trial is warranted; the usefulness of the new system has already been demonstrated in 45 patients in our department and more than 300 cases in a multicenter study which is currently under way.

Minimally invasive ventral spondylodesis for thoracolumbar fracture treatment: surgical technique and first clinical outcome

A new instrumentation system for ventral stabilization of the spine that can be used for an endoscopic and minimally invasive approach was developed. We describe the implantation technique and report on the first clinical results. This prospective study covers the first 45 patients to undergo this new technique since it was introduced in 1999. In all patients the operation was successfully performed in a completely minimally invasive procedure. Mono- and bisegmental stabilization was performed mainly at the thoracolumbar junction after initial posterior instrumentation in most cases. Lesions varied from fresh/old fractures to metastases (T5-L3). Pre- and postoperative follow-up included clinical examination and radiological visualization via X-ray and computed tomographic scan. Our experience with this minimally invasive procedure demonstrated the feasibility of the method.

Enhanced primary stability through additional cementable cannulated rescue screw for anterior thoracolumbar plate application

OBJECT

The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic. This is due to poor fixation strength of anterior screws in the adjacent segments. The aim of this study was to determine whether a new cemented and uncemented VB screw provides improved primary stability following placement of anterior instrumentation in cases of fracture.

METHODS

The primary stability-related parameters of a new uncemented/cemented screw were compared with those of conventional monocortical screw fixation in a burst fracture model in which strut graft and anterior overbridging instrumentation were used. The use of the new uncemented screw improved the range of motion (ROM) of the stabilized spine in flexion-extension by approximately 22%, in rotation by 20%, and in lateral bending by 15%. Additional cementation improved the ROM by approximately 41% in flexion-extension, 32% in rotation, and 30% in lateral bending compared with conventional monocortical screw fixation.

CONCLUSIONS

The new cannulated screw improves fixation strength and primary stability parameters. It is useful in the initial treatment of fractures in cases of poor bone quality and as a rescue device if previously inserted screws do not remain securely in place.

Image-guided endoscopic spine surgery: Part II: clinical applications

STUDY DESIGN

Endoscopic spinal procedures were performed under computed-tomography-based, image-guided assistance.

OBJECTIVE

To assess the clinical feasibility of applying a methodology that allows image-guided assistance in endoscopic spinal surgery.

SUMMARY OF BACKGROUND DATA

Endoscopic spinal procedures have become a part of the minimal invasive approaches to the spine. The main disadvantage of these techniques is the long learning curve and the lack of peroperative monitoring. Fluoroscopy does have disadvantages, such as positioning during surgery and the risk for radiation exposure. Fluoroscopy-based navigation has many advantages, however it is still based on preselected fluoroscopic images. There is no method that allows computed-tomography-based navigation in endoscopic conditions.

METHODS

Two patients have been operated on using endoscopic approaches assisted by computed-tomography-based navigational system. One had a thoracoscopic approach for median calcified disc herniation and another one had an endoscopic posterior approach for resection of a sacro-iliac osteophyte. For each patient, a frame of reference had been placed percutaneously and scanned. The computed tomography images were registered to the anatomy using the geometry of the frame as fiducials. Navigation through endoscopic approaches was possible in both cases.

RESULTS

In both cases navigation was reliable and a helpful monitoring to achieve the surgical goals through endoscopic approaches.

CONCLUSIONS

There are some factors that make endoscopic spine surgery a difficult start. Image-guided spine surgery is technically feasible and clinically applicable in endoscopic approaches.

Video-assisted thoracoscopic surgery in managing tuberculous spondylitis

The literature includes no studies on the use of video-assisted thoracoscopic surgery in the management of tuberculous spondylitis, and its role in the management of tuberculosis involving the thoracic spine remains unclear. The authors experience with 10 consecutive patients (six women, four men) who underwent video-assisted thoracoscopic surgery for the treatment of spinal tuberculosis involving levels from T5 to T11, from January 1996 to December 1997, was analyzed. Using the extended manipulating channel method (2.5-3.5 cm portal incisions), video-assisted thoracoscopic surgery was performed with a three-portal technique (seven patients) or a modified two-portal minithoracotomy technique that required a small incision for the thoracoscope and a larger incision, measuring 5 to 6 cm, for the procedures in three patients. All the patients were studied prospectively. The followup ranged from 17 to 42 months (mean, 24 months). Postoperative complications included one lung atelectasis. Pleural adhesions, owing to local inflammation or paravertebral abscess, were seen in four patients and one patient with severe pleurodesis needed an open technique for treatment. Postoperative air leaks were seen in four (40%) of 10 patients but all were transient. The average neurologic recovery was 1.1 grades on the Frankel's scale. The data from this series of patients with tuberculous spondylitis show that video-assisted thoracoscopic surgery has diagnostic and therapeutic roles in the management of tuberculous spondylitis. Technically, a combination of thoracoscopy and conventional spinal instruments to perform video-assisted thoracoscopic surgery through the extended manipulating channels, which were placed slightly more posterior than usual, was effective and safe.