Solid Bony Fusion Research Articles

A single-stage single-surgical approach for the treatment of pyogenic spinal infection

Background Pyogenic spinal infection (PSI) is the most common cause of spinal infection, affecting mainly the vertebral body. Nonoperative treatment is associated with high failure and mortality rates, especially in patients with impaired immune system. There is debate as regards the most appropriate approach and whether to use an implant at the infected site immediately or to wait for a second stage after a period of antibiotic coverage and whether to use one or combined anteroposterior approaches. Objective The aim of this work was to study the results of single-stage debridement, bone graft and immediate internal fixation for PSI cases through one approach. Study design This study was a retrospective review of 23 cases of PSI. Patients and methods The medical records, haematological results, radiological imaging, bacteriology and biopsy results of 23 patients of PSI were reviewed. The posterior approach was used in cases of thoracolumbar infection and the anterior approach was used in cervical spinal cases. Patients were treated with single-stage debridement, bone autograft and immediate internal fixation through the same approach, followed by parenteral antibiotics for 4-6 weeks and oral antibiotics until normalization of the inflammatory markers with good clinical and radiological response. Functional results were assessed using the Oswestry disability index questionnaire and the physical function domain score of SF-36 questionnaire. Results All patients showed complete resolution of infection and achieved solid bony fusion in a sound position without chronicity, relapse or persistence of infection. All patients showed neurological recovery and returned to their preoperative activity with good functional outcome as evidenced by significant improvement in the preoperative Oswestry disability index mean score and the physical function domain score of SF-36 questionnaire. Conclusion Single-stage single-approach surgical debridement, interbody fusion using bone graft and immediate internal fixation, is a safe and effective treatment for PSI.

C1 lateral mass screw placement in occipitalization with atlantoaxial dislocation and basilar invagination: a report of 146 cases.

Retrospective study of 146 patients with the diagnosis of occipitalization, atlantoaxial dislocation (AAD) and basilar invagination, using a novel surgical treatment strategy. To introduce a novel fixation and reduction technique. Atlas occipitalization associated with basilar invagination often result in fixed AAD that need reduction and occipitocervical fixation. The widely used occipitocervical fixation with suboccipital screws has several limitations such as the poor screw purchase in maldevelopment of the occipital bone, limited area available for implants in previous suboccipital craniectomy. The placement of occipitalized C1 lateral mass screw is an alternative option. From June 2007 to June 2013, 146 patients of occipitalized atlas with fixed AAD and basilar invagination, underwent fixation and reduction via C1 lateral mass and C2 pars/pedicle screw. A total of 143 patients achieved the follow-up in the range from 6 months to 4 years (average, 30 mo). Neurological improvement was seen in all the 143 patients, with the averaged Japanese Orthopedic Association scores increasing from 11.6 to 15.5. Radiographical evaluation showed that solid bony fusion was achieved in all patients, and complete reduction was attained in 95 patients, and partial reduction (>60%) in 40 patients, and no effective reduction in 8 patients who had additional transoral decompression. Magnetic resonance imaging demonstrated that the ventral cervicomedullary compression was relieved in all patients. Although technically demanding, the C1 lateral mass placement in occipitalization is very useful in the rescue situation where more conventional stabilization alternatives are not technically possible, or as routine occipitocervical stabilization. It provides firm stabilization offering an optimum situation for bony fusion, and meanwhile the effective reduction of fixed AAD and basilar invagination. An extremely high fusion rate can be expected with minimal complications and minimal postoperative immobilization with this technique.

Bone fusion rate in the thoracic and lumbar spine after laminoplasty with laminar screws.

Retrospective clinical study. The purpose of this study was to determine the bone fusion rate after laminoplasty with laminar screws. There are many procedures, mostly with miniplates and screws, to repair an opened lamina after surgery for intraspinal pathology. Laminoplasty with laminar screws is an alternative procedure; however, the surgical outcome of this procedure has not been reported before. Laminoplasty with laminar screws was performed in 40 consecutive patients (male to female ratio=18:22; age, 47.4±13.6 yr) after surgery for intradural pathology. The lamina flap, which was opened with a high-speed drill or Kerrison punch, was reattached to the host bone with bilateral laminar screws. The bony fusion was assessed with computed tomographic scans that were taken 14.1±6.4 months postoperatively. If the gap between the host bone and the grafted lamina was filled up with a bony bridge, it was regarded as "fused." The fusion rate was assessed in terms of the hemilamina, the operated level, and the patient. The operated level was considered fused when at least 1 side of the hemilamina was completely fused to the host bone. Fusion success for a patient was defined as "all operated levels were fused." The follow-up period was 40.7±13.8 months. Screw fixation was successfully achieved in 97.7% (150/154 hemilaminae, 77 levels) of the hemilaminae. Solid bony fusion was achieved in 56.7% (85/150) of the hemilaminae, 75.3% (58/77) of the operated levels, and 67.5% (27/40) of the patients. Screw breakage or displacement of the grafted laminae was not observed during the follow-up period. Laminoplasty with laminar screws had a 67.5% fusion rate, and migration of the grafted laminae was not observed in any of the patients probably due to additional fibrous unions. 4.

Autologous clavicle bone graft for anterior cervical discectomy and fusion with titanium interbody cage.

A variety of donor-site complications have been reported for anterior cervical discectomy and fusion (ACDF) using autologous iliac bone graft. To minimize such morbidities and to obtain optimal bony fusion at the ACDF surgery, a novel technique was used to harvest cancellous bone from the autologous clavicle instead of the popular iliac crest graft. After a routine cervical discectomy of the affected level, a 1.5-cm linear skin incision was made over the clavicle within 2.5 cm of the sternoclavicular joint on the medial one-third portion. This portion is known as an anatomically safe zone, with no subcutaneous distribution of the supraclavicular nerve. Then, cancellous bone was harvested through a small cortical window developed on the clavicle. Care was taken not to injure the subclavian major vessels and the lung below the clavicle. A box-type titanium cage was packed with the harvested cancellous bone and then inserted into the discectomy-treated space for cervical interbody fusion. From 2009 to 2013, 16 patients with cervical radiculopathy and/or myelopathy underwent single-level ACDF with this method. All but 1 patient experienced significant improvement of clinical symptoms after the surgery and showed radiographic evidence of solid bony fusion and spinal stabilization within 6 months. Further, no peri- and postoperative complications at the clavicular donor site were noted. The mean visual analog scale pain score (range 0 [no pain to 10 [maximum pain]) at 1 year after the surgery was 0.1, and 13 of 14 patients with data at 1-year follow-up were highly satisfied with their donor-site cosmetic outcome. The clavicle is a safe, reliable, and technically easy source of autologous bone graft that yields optimal fusion rates and patient satisfaction with ACDF surgery.

Outcome of Salvage Lumbar Fusion after Lumbar Arthroplasty

Study DesignRetrospective review.PurposeThis study aims to define the role of lumbar fusion for persistent back pains after the lumbar disc replacement.Overview of LiteratureLittle is written about lumbar fusion after optimally placed lumbar arthroplasty in patients with persistent lower back pains.MethodsRetrospective review of cases of lumbar artificial disc requiring subsequent fusion because of persistent back pains despite optimally placed artificial discs. Outcomes were evaluated using Oswestry Disability Index (ODI) and visual analogue scale (VAS). Clinical improvements indicated 25% improvement in ODI and VAS values.ResultsFive patients met the study criteria. The mean baseline ODI for the five patients was 52. The mean baseline VAS scores for back and leg pains were 76 and 26, respectively. All the five patients had optimally placed prosthesis. The indication for surgery was the constant low back pains found in all the patients. Revision surgery involved disc explantation and fusion in two of the patients and posterolateral fusion without removing the prosthesis in three. None of the patients achieved adequate pain control after the revision surgery despite the solid bony fusion documented by postoperative computed tomography. The mean ODI value after the fusion was 55. The mean values for back and leg pains VAS were 72 and 30, respectively.ConclusionsLack of good pain relief after successful lumbar artifical disc replacements may indicate different etiology for the back pains. The spine-treating surgeons should have a high threshold level to perform salvage fusion at that level.

Posterior realignment of irreducible atlantoaxial dislocation with C1–C2 screw and rod system: a technique of direct reduction and fixation

Background contextTreatment of chronic and irreducible atlantoaxial dislocation (AAD) with ventral compression is challenging for surgeons. The main procedures are occipitocervical/C1–C2 fusion after transoral odontoidectomy or release of the periodontoid tissues. These surgical procedures, which are performed simultaneously or intermittently, have many disadvantages that may discount their effectiveness. Therefore, a more effective way to achieve surgical reduction and to keep solid stability with only a single procedure is needed. PurposeWe describe a technique to reduce chronic and irreducible AAD with C1 lateral mass and C2 pedicle screw and rod system. Study designThis was a retrospective case series. Patient sampleOur sample comprised 26 patients (9 men and 17 women) with irreducible AAD who ranged in age from 15 to 54 years (mean, 35 years). Outcome measuresPatients' neurologic status was evaluated with the Japanese Orthopedic Association (JOA) scale. MethodsTwenty-six symptomatic patients underwent posterior realignment and reduction through the C1 lateral mass and C2 pedicle screw and rod system. The proposed mechanism of reduction is that the implanted screws and rods between C1 and C2 acting as a lever system drew C1 backward and pushed C2 downward and forward after removing circumambient obstruction and scars and thoroughly releasing the facet joints. The preoperative and postoperative JOA score, the extent of reduction, and the conditions of C1–C2 bony fusion were examined. ResultsNo neurovascular injury occurred during surgery. Follow-up ranged from 6 to 40 months (mean 20.7 months). Radiographic evaluation showed that solid bony fusion was achieved in all patients, and that complete reduction was attained in 18 patients and partial reduction (>60% reduction) in 8 patients. The mean postoperative JOA score at last follow-up was 15.7, compared with the preoperative score of 12.1 (p<.01). ConclusionsThis C1–C2 screw and rod system provides reliable stability and sufficient reduction of the anatomic malalignment at the craniovertebral junction and meanwhile retains the mobility of atlanto-occipital joints in the treatment of chronic and irreducible AAD. Sophisticated skills, thorough release of the facet joints, and intraoperative protection of the vertebral artery are key points to accomplish this technique.

Plasmapore-Coated Titanium Cages for Anterior Cervical Discectomy and Fusion

n this issue of WORLD NEUROSURGERY, Takeuchi et al. assessed fusion rates of Plasmapore-covered titanium I cervical cages compared with noncoated titanium cages in patients who received anterior cervical discectomy and fusion (ACDF). Their study was a retrospective cohort study by design and included 30 patients in the Plasmapore-coated titanium cage (PPC) group and 42 patients in the non-Plasmapore-coated titanium cage (N-PPC) group who were followed for at least 24 months. Patients underwent standard 1-level ACDF with no additional cervical instrumentation. All cages were unpacked. Patients were followed at 3, 6, 12, and 24 months by 2 independent observers using flexion and extension radiographs and thin-cut computed tomography scan. Criteria of evaluation were radiologic stabilization and solid bony fusion. There were no surgical or perioperative complications.

Posterior-approach Vertebral Replacement With Rectangular Parallelepiped Cages (PAVREC) for the Treatment of Osteoporotic Vertebral Collapse With Neurological Deficits

A retrospective clinical study. To assess the efficacy of a new spinal reconstruction technique (posterior-approach vertebral replacement with rectangular parallelepiped cages: PAVREC) for the treatment of osteoporotic late vertebral collapse with neurological deficits. Poor bone quality and medically complicated situations obfuscate precise treatment for paraplegia caused by osteoporotic vertebral collapse. Recently, posterior-approach corpectomy and replacement with a cylindrical cage have been proposed. However, postoperative cage subsidence and kyphosis progression frequently occurs. Surgical invasiveness, perioperative complications, and clinical and radiographic outcomes in a total of 19 consecutive patients with osteoporosis (7 men and 12 women; mean age, 75 y) who underwent PAVREC with a mean follow-up period of 45.6 months (range, 16-79 mo) were reviewed. The affected vertebral levels ranged from T12-L4. The mean bone mineral density of the femoral neck was 0.611±0.077 g/cm(2) (mean±SD). Mean operative time was 261 minutes (range, 155-326 min). Mean blood loss was 664 mL (range, 197-1595 mL). There were no reported surgical complications. Neurological deficits evaluated with the Frankel grading score improved >1 grade after surgery in all patients. Mean preoperative visual analog scale scores for back or leg pain (7.2; range, 6-9) significantly improved after surgery (1.4; range, 0-2) (P<0.05). Local kyphosis improved from a mean of 24.6 degrees before surgery to a mean of 1.5 degrees after surgery (P< 0.05), and it was maintained at a mean of 2.5 degrees at the final follow-up. Although screw loosening, cage subsidence, and subsequent vertebral fracture were seen in several cases, no additional surgeries were needed. Solid bony fusion was confirmed in all cases. PAVREC provided a satisfactory clinical and radiologic outcome without severe complications. This procedure can be a treatment option for osteoporotic vertebral collapse and an alternative to an anterior-approach or single posterior-approach reconstruction with a cylindrical cage.

In situ posterolateral and fibular interbody fusion in High grade spondylolysthesis

Objective. High-grade spondylolysthesis and spondyloptosis management have various options. There were no large series reported to support any particular treatment modality. The aim of surgery is to get solid bony fusion to get relief of instability and its symptoms as well as relief of neurological symptoms. There are many treatment options which are associated with technical difficulties and high incidence of complications and failures. In situ transsacral fibular graft with posterolateral fusion along with posterior decompression is a good surgical option. It offers anterior and posterolateral fusion for instability pain and relief of neurological symptoms in most of the patients. It is technically simple, with no major surgery-related complications. Materials and methods. The cases of high-grade spondylolysthesis operated since 2008 with one year minimal follow up were included in this study. Six cases were operated during this period. All were females in their second and third decade of life. All of them had transsacral fibular grafting with posterolateral fusion and decompression. One of the cases had additional anterior procedure with sacral widening with bone graft. The clinical status and bony fusion has been assessed at the end of one year after surgery and also for assessing final outcome. Results. All the patients had solid bony fusion with no progression of slip and are pain free and relived of neurological symptoms. Conclusions. In situ transsacral fibular graft with posterolateral fusion and posterior decompression is technically simple surgical option with minimal risks and reliable outcome.

Posterior instrumentation, anterior column reconstruction with single posterior approach for treatment of pyogenic osteomyelitis of thoracic and lumbar spine

Surgical treatment of thoracolumbar osteomyelitis consists of radical debridement, reconstruction of anterior column either with or without posterior stabilization. The objective of present study is to evaluate a case series of patients with osteomyelitis of thoracic and lumbar spine treated by single, posterior approach with posterior instrumentation and anterior column reconstruction. Seventeen patients underwent clinical and radiological evaluation pre and postoperatively with latest follow-up at 19 months (8-56 months) after surgery. Parameters assessed were site of infection, causative organism, angle of deformity, blood loss, duration of surgery, ICU stay, deformity correction, time to solid bony fusion, ambulatory status, neurologic status (ASIA impairment scale), and functional outcome (Kirkaldy-Willis criteria). Mean operating time was 207 min and average blood loss 1,150 ml. Patients spent 2 (1-4) days in ICU and were able to walk unaided 1.6 (1-2) days after surgery. Infection receded in all 17 patients postoperatively. Solid bony fusion occurred in 15 out of 17 patients (88 %) on average 6.3 months after surgery. Functional outcome was assessed as excellent or good in 82 % of cases. Average deformity correction was 8 (1-18) degrees, with loss of correction of 4 (0-19) degrees at final follow-up. Single, posterior approach addressing both columns poses safe alternative in treatment of pyogenic vertebral osteomyelitis of thoracic and lumbar spine. It proved to be less invasive resulting in faster postoperative recovery.

Four-level anterior cervical discectomies and cage-augmented fusion with and without fixation

Anterior cervical decompression and fusion is a well-established procedure for the treatment of cervical spinal canal stenosis. In this study, we evaluated the necessity of spinal instrumentation after four-level anterior cervical decompression and cage fusion. From January 2006 until August 2008, 25 patients (8 females and 17 males) (mean age 63.9 ± 7.9 years) suffering from spinal stenosis C3-C7 underwent anterior decompression and interbody fusion. The patients were divided into two groups. Four-level discectomy and cage fusion was performed in all patients. In group A including nine patients, posterior instrumentation with a lateral mass screw-rod system was added, while in group B including 16 patients, additional instrumentation was not performed. The mean duration of follow-up was 48.6 months (average 25-67 months). Clinically, the mean value for the Neck Disability Index improved from 40 ± 23.25 at presentation to 16.31 ± 15.09 at the final follow-up. The difference between the two groups was statistically not significant. Radiologically, the criteria for solid bony fusion were achieved successfully in all patients of group A, and in 87.5 % of patients in group B. The difference between the two groups was statistically not significant. The fused segment was then evaluated in the sagittal radiographs as regards the height and the lordosis angle. The loss in the height as well as the loss in the lordosis angle was more when posterior instrumentation was not added. However, the difference between the two groups was not statistically significant. Stand-alone intersomatic cage fusion is an acceptable line of treatment for four-level cervical disc disease, both clinically and radiologically. Although the addition of posterior instrumentation yields better radiological results, the difference does not reach the statistical significance level.

Unstable atlas fractures treated by anterior plate fixation through transoral approach

Objective To explore the clinical outcomes of anterior plate fixation through transoral ap- proach in the treatment of unstable atlas fractures. Methods From March 2004 to May 2010, 20 patients with unstable atlas fractures were treated by anterior plate fixation through transoral approach, including 12 males and 8 females, aged from 23 to 68 years （average, 47.7±13.9 years）. Of the 20 cases of unstable atlas fractures, 4 cases were classified as anterior 1/2 Jefferson fracture, 8 cases as 1/2 ring Jefferson fracture, and 8 cases as anterior 3/4 ring Jefferson fracture. The preoperative average VAS scores were 6.0±1.3 points, ranged from 4 to 8 points. Clinical and imaging examinations were performed during follow-up period to eval- uate the outcomes. Results All patients were followed up for 12 to 81 months, with an average of 48.5＋ 20.0 months. There were no screw loosing and breakage, no plate displacement, and no spinal cord and ver- tebral artery injury during operation. A total of 20 plates were placed and all 40 screws were inserted into at- las lateral mass. Computed tomography scans demonstrated 2 screws were placed too close to the vertebral artery canal, but without clinical consequences. The postoperative VAS scores were from 0 to 3 points with an average of 1.3＋1.0 points. Static and dynamic films 6 months after surgery demonstrated that fusion was achieved in all cases. Atlantoaxial rotational function was restored satisfactorily. No plate-related complica- tion was observed in all patients in the whole follow-up period. Conclusion Anterior plate fixation through transoral approach is an effective method for management of unstable atlas fractures, which has advantages such as solid bony fusion and low incidence of comulication. Key words: Atlas; Fractures, closed; Fracture fixation, internal; Treatment outcome

Efficacy of pedicle screw technique in treatment of os odontoideum combined with atlantoaxial dislocation

Objective To evaluate the efficacy and radiological variation of pedicle screw technique in the treatment of os odontoideum combined with atlantoaxial dislocation. Methods Fifteen patients with os odontoideum combined with atlantoaxial dislocation were treated with occipitocervical fusion or atlantoaxial fixation.Two patients with irreducible atlantoaxial dislocation were treated surgically with transoral anterior atlantoaxial release and one treated with posterior arch removal plus occipitocervical fusion.Two patients with atlas deformity and one infant were treated with occipitocervical fusion.The rest patients were treated with posterior reduction and pedicle screw internal fixation.Clinical manifestations and imaging changes were followed up to evaluate the clinical efficacy. Results All patients were followed-up for average 26 months (range,7-47 months).Neurological recovery was significantly improved in 13 patients and took a turn for the better in two.The average JOA scores was increased from average preoperative 8.27 to postoperative 15. According to Hirabayashi,the average improvement rate was77％,including 10 patients with excellent outcomes and five with good outcomes,with excellence rate of100％.The cervical-medullary angle was increased from average preoperative 130.3° to postoperative151.7°.Postoperative X-rays and CT showed good atlantoaxial alignment and solid bony fusion in all pa-tients,with no shedding or breakage of the fixators. Conclusion Occipitocervical fusion or adantoaxial fixation through pedicle screw technique is an effective method for treatment of os odontoideum combined with irreducible atlantoaxial dislocation. Key words: Spinal fractures; Atlas; Axis; Fracture fixation, internal

Posterolateral Spondylodesis Using Bioactive Glass S53P4 and Autogenous Bone in Instrumented Unstable Lumbar Spine Burst Fractures

A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of unstable lumbar spine burst fractures during 1996-1998 was conducted. The lumbar fractures were fixed using posterior USS instrumentation. BAG was implanted on the left side of the fusion-bed and AB on the right side. The operative outcome was evaluated on X-rays and CT scans, and a clinical examination was also performed. The Oswestry score was excellent, and the mean pain score 1. The mean compression rate of the injured vertebral body was 25%. A solid bony fusion was seen on CT scans on the AB side in all patients and on the BAG side in five patients, and a partial fusion in five patients, resulting in a total fusion-rate of 71% of all fused segments in the BAG group. Our long-term results show that BAG-S54P4 bone graft material is safe to be used as a bone graft extender in spine surgery.

Intraoperative determination of the load–displacement behavior of scoliotic spinal motion segments: preliminary clinical results

Spinal fusion is a widely and successfully performed strategy for the treatment of spinal deformities and degenerative diseases. The general approach has been to stabilize the spine with implants so that a solid bony fusion between the vertebrae can develop. However, new implant designs have emerged that aim at preservation or restoration of the motion of the spinal segment. In addition to static, load sharing principles, these designs also require a profound knowledge of kinematic and dynamic properties to properly characterise the in vivo performance of the implants. To address this, an apparatus was developed that enables the intraoperative determination of the load-displacement behavior of spinal motion segments. The apparatus consists of a sensor-equipped distractor to measure the applied force between the transverse processes, and an optoelectronic camera to track the motion of vertebrae and the distractor. In this intraoperative trial, measurements from two patients with adolescent idiopathic scoliosis with right thoracic curves were made at four motion segments each. At a lateral bending moment of 5 N m, the mean flexibility of all eight motion segments was 0.18 ± 0.08°/N m on the convex side and 0.24 ± 0.11°/N m on the concave side. The results agree with published data obtained from cadaver studies with and without axial preload. Intraoperatively acquired data with this method may serve as an input for mathematical models and contribute to the development of new implants and treatment strategies.

Corpectomy with titanium cage reconstruction in the cervical spine

Multi-level anterior cervical discectomy and fusion (ACDF) has been utilized by many surgeons to address multi-level cervical disease with the use of autograft or allograft. High failure rates have been reported in three-level decompressions when autograft is used, which increases with the use of allograft. This has led many surgeons to advocate anterior cervical corpectomy with strut grafting where only two surfaces are needed for fusion compared to the multiple surfaces required for multi-level ACDF. We retrospectively evaluated the efficacy of titanium cage use with autologous bone graft (resected vertebral bodies) and anterior cervical plating in 38 consecutive patients (aged 18–73years) undergoing cervical decompression and corpectomy. Medical records were examined along with an outcome interview conducted in-person or by phone. Postoperative immobilization was achieved with a rigid cervical collar. Fusion was assessed by antero-posterior (AP), lateral, and flexion–extension radiographs and cervical spine CT scans. Fusion was assessed by AP, lateral, and flexion–extension radiographs and cervical spine CT scans. Clinical results included an exit interview. Solid bony fusion with graft incorporation was found in 37 of 38 patients (97.5%) at six months and 100% in one year. Compared to preoperative levels, 84% of patients rated their overall quality of life to have improved by 50% or greater and would have the same surgery again given the same conditions. There were few complications. Thus, titanium cage reconstruction with the use of autologous bone from a corpectomy and the use of an anterior cervical plate is an effective means of reconstruction after decompressive cervical corpectomy, and we conclude this is a viable alternative to multi-level ACDF or to procedures involving long strut grafts obtained from the patient or bone bank.

Single-stage anterior debridement and fusion with autografting and internal fixation for pyogenic lumbar spondylodiscitis

Patients with pyogenic lumbar spondylodiscitis can be successfully treated by non-operative methods. However, the typical operation for this condition includes debridement of the infected site, bone grafting and internal fixation to stabilize the spine. Single-stage anterior debridement and fusion with autografting and internal fixation of one spinal segment were performed on nine patients with pyogenic lumbar spondylodiscitis. This operative procedure is rarely documented for pyogenic lumbar spondylodiscitis. To evaluate the safety and effectiveness of single-stage anterior debridement, autografting and internal fixation of one spinal segment for pyogenic lumbar spondylodiscitis. At the final follow-up, seven out of the nine patients were pain free. Two patients had mild, intermittent back pain (Visual Analogue Scale rating of 1-2), which represented an improvement from their preoperative pain. All nine patients had no clinical, laboratory or radiological evidence of recurrence of infection. Moreover, all the patients showed solid bony fusion. Based on the limited population studied, it suggested that this technique may be a safe and effective operative procedure for appropriate pyogenic lumbar spondylodiscitis in patients.

Pedicle subtraction osteotomy through pseudarthrosis to correct thoracolumbar kyphotic deformity in advanced ankylosing spondylitis

Surgical treatment is mandatory for spinal pseudarthrosis in advanced ankylosing spondylitis (AS) patients with painful sagittal deformity and/or neurological deficits. However, the most effective and safe surgical procedure for AS-related symptomatic thoracolumbar pseudarthrosis is still controversial. The purpose of this study is to explore the outcomes of pedicle subtraction osteotomy (PSO) at the level of pseudarthrotic lesion combined with supplemental anterior fusion for patients suffering from kyphotic pseudarthrosis in AS. Seven AS patients with thoracolumbar pseudarthrosis and kyphotic deformity were reviewed. There were 6 males and 1 female with a mean age of 41.7years. All patients had back pain. Imaging findings demonstrated 3-column extensive discovertebral destruction in all patients. The preoperative global kyphosis averaged 75° (range, 37°-114°) with the apex at the level of pseudarthrosis. Three patients had incomplete neurological deficits (Frankel D) preoperatively. All patients underwent PSO at the level of pseudarthrosis in the first stage followed by supplemental anterior fusion in the second stage. Radiographic and clinical outcomes were assessed with an average follow-up of 38months (range, 24-59months). The visual analogue scale (VAS) was compared before surgery and at the final follow-up. All patients showed significant pain relief postoperatively and were satisfied with the kyphosis correction as well. Solid bony fusion was shown at the final follow-up. Three patients with neurological deficits had complete recovery of neurological function. The global kyphosis was corrected from 75º to 30º, with a mean correction of 45º. The VAS showed significant improvement. No surgical complication was observed. PSO can be safely performed through the site of pseudarthrotic lesion in AS patients with pseudarthrosis and kyphotic deformity. After PSO, supplemental anterior fusion is sometimes necessary to support the anterior and middle column in a second stage if there is a bone defect in the osteotomy site.

Instrumented Spondylodesis in Degenerative Spondylolisthesis With Bioactive Glass and Autologous Bone

A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of degenerative spondylolisthesis during 1996 to 1998 was conducted. The surgical procedure was a standardized instrumented posterolateral fusion that used USS/VAS. BAG was implanted on the left side of the fusion bed and AB on the right side. The operative outcome was evaluated on x-rays and computed tomography scans, and a clinical examination was also performed. Seventeen patients (12 women, 5 men) participated in the 11-year follow-up. The mean Oswestry Disability Index score at the follow-up was 21 (range 0 to 52), compared with 49 (range 32 to 64) at the preoperative time. A solid bony fusion was seen on computed tomography scans on the AB side in all patients and on the BAG side in 12 patients. The fusion rate of all fusion sites (n=41) for BAG as a bone substitute was 88% at the L4/5 level and 88% at the L5/S1 level. The use of BAG as a bone graft extender can be considered as a good alternative in spinal surgery in the future.

Endoscope-assisted combined anterior and posterior procedures for spondylolisthesis

Objective To evaluate the clinical outcome of endoscope-assisted combined anterior and posterior procedures for grade-Ⅲ and Ⅳspondylolisthesis.Methods From December 2007 to May 2010,13 patients with grade-Ⅲ and Ⅳ spondylolisthesis were treated with two bilateral decompression,percutaneous pedicle screw restoration,intervertebral bone grafting and plate fixation using microendoscopic discectomy and laparoscopy,including 6 males and 7 females with an average age of 39.8 years (range,18-58 years).Eleven cases were in grade Ⅲ spondylolisthesis and two in Ⅳ.The lesion location was as follows:2 cases were at L4,5 and 11 at L5S1.The clinical outcomes were evaluated according to Oswestry disability questionnaire,and the change of radiographic data including slipping degree,slipping angle and posterior height of intervertebral disc.Results The mean follow-up time was 21 months (range,12-36 months).The mean operative time was 125 min,with a mean blood loss of 415 ml.Slipping degree decreased 56.9％ in average (from preoperative 73.3％±6.1％ to postoperative 16.4％±9.5％),slipping angle decreased 19.6°(from preoperative 27.7°±5.6° to postoperative 8.1°±8.8°),posterior height of intervertebral disc increased 7.1 mm (from preoperative 2.6 ±0.8 mm to postoperative 9.7 ±3.7 mm).The clinical outcomes of the Oswestry disability questionnaire decreased 19.5 (from preoperative 35.8±5.7 to postoperative 16.3±5.2).CT scans demonstrated that solid bony fusion could be obtained in one year after operation.Complications included dural sac tears in 1 case,and superficial incision infection in 1.The results were excellent in 4 cases,good in 8 and fair in 1.Conclusion Endoscope-assisted anterior and posterior procedures for grade-Ⅲ and Ⅳ spondylolisthesis is a reliable method,which can lead to rigid fixation and fusion,and also can achieve thorough decompression and restoration as much as possible. Key words: Laparoscopes; Spondylolisthesis; Treatment outcome