Clinical evaluation of a bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate: 128 osteoporotic patients with 42 months of follow-up

OBJECTIVES: To evaluate the safety and efficacy of a novel bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate in osteoporotic spinal surgery. METHODS: This study included 128 patients with osteoporosis (BMD T-score −3.2±1.9; range, −5.4 to -2.5) who underwent spinal decompression and instrumentation with a polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw. Postoperative Visual Analogue Scale scores and the Oswestry Disability Index were compared with preoperative values. Postoperative plain radiographs and computed tomography (CT) scans were performed immediately after surgery; at 1, 3, 6, and 12 months; and annually thereafter. RESULTS: The mean follow-up time was 42.4±13.4 months (range, 23 to 71 months). A total of 418 polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screws were used. Cement extravasations were detected in 27 bone cement-injectable cannulated pedicle screws (6.46%), mainly in cases of vertebral fracture, without any clinical sequela. The postoperative low back and lower limb Visual Analogue Scale scores were significantly reduced compared with the preoperative scores (<0.01), and similar results were noted for the Oswestry Disability Index score (p<0.01). No significant screw migration was noted at the final follow-up relative to immediately after surgery (p<0.01). All cases achieved successful bone fusion, and no case required revision. No infection or blood clots occurred after surgery. CONCLUSIONS: The polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw is safe and effective for use in osteoporotic patients who require spinal instrumentation.

Roles of 99mTc-MDP and SPECT/CT fusion imaging in the diagnosis and treatment decisions of bone metastasis of malignant tumors / 实用医学杂志

Objective To evaluate the role of (99)Tc(m)-MDP SPECT/CT bone fusion imaging in diagnosis and treatment strategy establishment of patients with bone metastatic malignancy.Methods Retrospective study was carried out on 66 patients (55 patients with primary malignant tumors,11 patients with primary benign bone disease) chosen from 117 patients who had undergone whole body bone scintigraphy and SPECT/CT fusion imaging examination.Comparison was carried out on diagnostic efficacy for bone metastases and changes of treatment between SPECT/CT fusion imaging and other anatomical imaging (CT and/or MR).Cases excluded are extensive bone metastases and no final diagnosis of patients.Results For diagnosis of patient with bone metastasis and bone metastasis lesion,the sensitivity of SPECT/CT fusion imaging was (90.62％,93.88％),specificity (79.41％,89.47％) and accuracy (84.84％,90.97％),while sensitivity of simple anatomical imaging was (59.38％,51.02％),specificity (94.11％,94.73％) and accuracy (77.27％,79.86％),with a significant difference (P ＜ 0.05).SPECT/CT fusion imaging changed 30.31％ (20/66) the patient's treatment plan,while 16.67％ (11/66) for simple anatomical imaging,with a significant difference (P ＜ 0.05).Conclusions SPECT/CT fusion imaging could increase the accuracy of diagnosis of bone metastases and have an important role in establishing the treatment strategy.

The Therapeutic Effects of Combination Therapy with Curcumin and Alendronate on Spine Fusion Surgery in the Ovariectomized Rats

OBJECTIVE: The purpose of this study was to evaluate the therapeutic effects of combination therapy with curcumin and alendronate on spine fusion surgery in ovariectomized rats. METHODS: Thirty-two female Sprague-Dawley rats (12 weeks old) underwent bilateral ovariectomy (OVX). Eight weeks after surgery, animals underwent intertransverse spine fusion at L4–5. The rats were randomly distributed amongst 4 groups; untreated OVX group, curcumin administered group, alendronate administered group, and the combination therapy group. At 8 weeks after fusion surgery, the animals were sacrificed and the fusion mass was assessed by manual palpation, radiographic scan, and micro-computed tomographic scan. In addition, mechanical strength was determined by a 3-point bending test. RESULTS: Based on the results of manual palpation testing and 3-dimensional micro-computed tomography scanning, solid bone fusion rate was 50% (4 of 8) in the OVX group, 75% (6 of 8) in the alendronate-only and curcumin-only group, and 87.5% (7 of 8) in the combination therapy group, respectively. The combination therapy group had a higher fusion rate compared with the other treatment groups, though not statistically significantly (p>0.05). And the combination therapy group had a significant increase in fusion volume at 8 weeks after spine fusion surgery compared with curcumin-only group (p=0.039). The 3-point bending test showed that combination therapy group had a significantly greater maximal load value compared to that of curcumin-only group (p=0.024). CONCLUSION: The present study demonstrated that additional treatment of curcumin and alendronate after spine fusion surgery in rat can promote higher fusion volume, and improve bone mechanical strength.

The Effect of Perioperative Radiation Therapy on Spinal Bone Fusion Following Spine Tumor Surgery

INTRODUCTION: Perioperative irradiation is often combined with spine tumor surgery. Radiation is known to be detrimental to healing process of bone fusion. We tried to investigate bone fusion rate in spine tumor surgery cases with perioperative radiation therapy (RT) and to analyze significant factors affecting successful bone fusion. METHODS: Study cohort was 33 patients who underwent spinal tumor resection and bone graft surgery combined with perioperative RT. Their medical records and radiological data were analyzed retrospectively. The analyzed factors were surgical approach, location of bone graft (anterior vs. posterior), kind of graft (autologous graft vs. allograft), timing of RT (preoperative vs. postoperative), interval of RT from operation in cases of postoperative RT (within 1 month vs. after 1 month) radiation dose (above 38 Gy vs. below 38 Gy) and type of radiation therapy (conventional RT vs. stereotactic radiosurgery). The bone fusion was determined on computed tomography images. RESULT: Bone fusion was identified in 19 cases (57%). The only significant factors to affect bony fusion was the kind of graft (75% in autograft vs. 41 in allograft, p=0.049). Other factors proved to be insignificant relating to postoperative bone fusion. Regarding time interval of RT and operation in cases of postoperative RT, the time interval was not significant (p=0.101). CONCLUSION: Spinal fusion surgery which was combined with perioperative RT showed relatively low bone fusion rate (57%). For successful bone fusion, the selection of bone graft was the most important.

Repeated Complication Following Atlantoaxial Fusion: A Case Report

A patients with atlantoaixial instability and osodontoideum underwent atlantoaixial fusion (Harms and Melcher technique) with demineralized bone matrix. But, unfortunately, the both pedicle screws in C2 were fractured within 9 weeks follow-up periods after several suspected episode of neck hyper-flexion. Fractured screws were not contact to occipital bone in several imaging studies, but it could irritate the occipital bone when neck extension because the relatively close distance between the occipital bone and C1 posterior arch. The patient underwent revision operation with translaminar screw fixation with autologus iliac bone graft. Postsurgical course were uneventful except donor site pain, but the bony fusion was not satisfied after 4 months follow-up. The patient re-underwent revision operation in other hospital. Continuous complication after atlantoaixial fusion is rare, but the clinical course could be unlucky to patients. Postoperative immobilization could be important to prevent the unintended clinical course of patients.

Allogeneic bone combined with autologous bone marrow stem cell transplantation for the treatment of benign bone tumors and tumor-like lesions / 中国组织工程研究

BACKGROUND:Al ogenic bone is a clinical commonly used bone graft material, but the osteoinductive capacity is the biggest problem. OBJECTIVE:To evaluate the effect of al ogeneic bone combined with autologous bone marrow stem cells on the repair of bone defects after scraping or resection of benign bone tumors and tumor-like lesions. METHODS:Sixty-five cases of benign bone tumors (including patients with tumor-like lesions) were divided into two groups according to bone graft. There were 35 cases in the composite bone marrow stem cells for bone graft group, and 20-40 mL red bone marrow were extracted from anterosuperior iliac spine or iliac spine on both sides according to the expected amount of bone graft, then the bone marrow stem cells were isolated, purified, cultured and amplified for standby, and the bone marrow stromal stem cells and al ogeneic bone particles were ful y blended before bong graft. After tumor scraping or resection, the blended bone marrow stromal stem cells and al ogeneic bone particles were implanted into the bone defect region. In the bone graft group, the bone defect was implanted with al ogeneic bone soaked with saline for half an hour. X-ray examination was performed at 1, 3, 6 and 12 months after treatment to compare the fuzzy boundary and the time for disappear, and the postoperative complications were observed. RESULTS AND CONCLUSION:Al the 62 patients were fol owed-up for more than 12 months. The fuzzy boundary time and disappear time in the composite bone marrow stem cells for bone graft group were shorter than those in the bone graft group (P<0.05). In the composite bone marrow stem cells for bone graft group, one case appeared rejection and healed after treated with immunosuppressive agents for 2 weeks, and no complication observed in two groups. The results indicate that al ogeneic bone composite autologous bone marrow stem cells for bone graft can promote bone fusion and bone defect healing.

Effect of Dietary Calcium on Spinal Bone Fusion in an Ovariectomized Rat Model

OBJECTIVE: To evaluate the effect of calcium supplementation on spinal bone fusion in ovariectomized (OVX) rats. METHODS: Sixteen female Sprague Dawley rats underwent bilateral ovariectomy at 12 weeks of age to induce osteoporosis and were randomly assigned to two groups : control group (n=8) and calcium-supplemented group (OVX-Ca, n=8). Autologous spinal bone fusion surgery was performed on both groups 8 weeks later. After fusion surgery, the OVX-Ca group was supplemented with calcium in drinking water for 8 weeks. Blood was obtained 4 and 8 weeks after fusion surgery. Eight weeks after fusion surgery, the rats were euthanized and the L4-5 spine removed. Bone fusion status and fusion volume were evaluated by manual palpation and three-dimensional computed tomography. RESULTS: The mean fusion volume in the L4-5 spine was significantly greater in the OVX-Ca group (71.80+/-8.06 mm3) than in controls (35.34+/-8.24 mm3) (p<0.01). The level of osteocalcin, a bone formation marker, was higher in OVX-Ca rats than in controls 4 weeks (610.08+/-10.41 vs. 551.61+/-12.34 ng/mL) and 8 weeks (552.05+/-19.67 vs. 502.98+/-22.76 ng/mL) after fusion surgery (p<0.05). The level of C-terminal telopeptide fragment of type I collagen, a bone resorption marker, was significantly lower in OVX-Ca rats than in controls 4 weeks (77.07+/-12.57 vs. 101.75+/-7.20 ng/mL) and 8 weeks (69.58+/-2.45 vs. 77.15+/-4.10 ng/mL) after fusion surgery (p<0.05). A mechanical strength test showed that the L4-5 vertebrae in the OVX-Ca group withstood a 50% higher maximal load compared with the controls (p<0.01). CONCLUSION: Dietary calcium given to OVX rats after lumbar fusion surgery improved fusion volume and mechanical strength in an ovariectomized rat model.

Short Segment Screw Fixation without Fusion for Unstable Thoracolumbar and Lumbar Burst Fracture : A Prospective Study on Selective Consecutive Patients

OBJECTIVE: The purpose of this prospective study was to evaluate the efficacy and safety of screw fixation without bone fusion for unstable thoracolumbar and lumbar burst fracture. METHODS: Nine patients younger than 40 years underwent screw fixation without bone fusion, following postural reduction using a soft roll at the involved vertebra, in cases of burst fracture. Their motor power was intact in spite of severe canal compromise. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The patients underwent removal of implants 12 months after the initial operation, due to possibility of implant failure. Imaging and clinical findings, including canal encroachment, vertebral height, clinical outcome, and complications were analyzed. RESULTS: Prior to surgery, the mean pain score (visual analogue scale) was 8.2, which decreased to 2.2 at 12 months after screw fixation. None of the patients complained of worsening of pain during 6 months after implant removal. All patients were graded as having excellent or good outcomes at 6 months after implant removal. The proportion of canal compromise at the fractured level improved from 55% to 35% at 12 months after surgery. The mean preoperative vertebral height loss was 45.3%, which improved to 20.6% at 6 months after implant removal. There were no neurological deficits related to neural injury. The improved vertebral height and canal compromise were maintained at 6 months after implant removal. CONCLUSION: Short segment pedicle screw fixation, including fractured level itself, without bone fusion following postural reduction can be an effective and safe operative technique in the management of selected young patients suffering from unstable burst fracture.

Short Segment Screw Fixation without Fusion for Unstable Thoracolumbar and Lumbar Burst Fracture : A Prospective Study on Selective Consecutive Patients

OBJECTIVE: The purpose of this prospective study was to evaluate the efficacy and safety of screw fixation without bone fusion for unstable thoracolumbar and lumbar burst fracture. METHODS: Nine patients younger than 40 years underwent screw fixation without bone fusion, following postural reduction using a soft roll at the involved vertebra, in cases of burst fracture. Their motor power was intact in spite of severe canal compromise. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The patients underwent removal of implants 12 months after the initial operation, due to possibility of implant failure. Imaging and clinical findings, including canal encroachment, vertebral height, clinical outcome, and complications were analyzed. RESULTS: Prior to surgery, the mean pain score (visual analogue scale) was 8.2, which decreased to 2.2 at 12 months after screw fixation. None of the patients complained of worsening of pain during 6 months after implant removal. All patients were graded as having excellent or good outcomes at 6 months after implant removal. The proportion of canal compromise at the fractured level improved from 55% to 35% at 12 months after surgery. The mean preoperative vertebral height loss was 45.3%, which improved to 20.6% at 6 months after implant removal. There were no neurological deficits related to neural injury. The improved vertebral height and canal compromise were maintained at 6 months after implant removal. CONCLUSION: Short segment pedicle screw fixation, including fractured level itself, without bone fusion following postural reduction can be an effective and safe operative technique in the management of selected young patients suffering from unstable burst fracture.

Non-fusion without decompression for surgical treatment of unstable AO type A thoracolumbar fractures / 中华创伤杂志

Objective To discuss the role of non-fusion without decompression in surgical treatment of unstable AO type A thoracolumbar fractures. Methods A retrospective study was performed on 42 patients with AO type A thoracolumbar fractures (T11-L2) treated with short segment pedicle screw fixation from February 2004 to February 2008. Patients were divided into two groups, ie, Croup A (treated with short segmental pedicle screw fixation without decompression or fusion) and Group B (treated with short segmental pedicle screw fixation without decompression but with fusion). The pre-operative, postoperative and follow-up local kyphotic angle, vertebrae compression rate were compared between two groups. Results In Croup A, average local kyphotic angle and average vertebrae compression rate were 19.1° (15. 4°-29. 8°) and 46% (30%-63%) respectively before operation, but 5. 0° (0. 3°-10.3°) and 10% (0-28%) respectively after operation. Twenty-one patients were followed up for average 21.2 months (12-46 months), which showed average local kyphotic angle of 7° (1.8°-10.7°) and average vertebrae compression rate of 10% (2% -22%) at final follow-up. In Croup B, average local kyphotic angle and average vertebrae compression rate were 25.8° (15.9°-34.5°) and 55% (30%-76%) respectively before operation, but 7.1° (1.5°-19. 1°) and 15% (0-28%) respectively after operation. Fifteen patients were followed up for mean 17.9 months (12-31 months) , which showed mean local kyphotic angle of 8.3° (0.7°-19.2°) and average vertebrae compression rate of 15% (l%-26%) at final follow-up. There was no pseudarthrosis, implant breakage, pedicle screw pull-out or severe back pain. There was statistical difference in local kyphotic angle and vertebrae compression rate between two groups.Conclusion Unstable AO type A thoracolumbar fractures with minor neurological deficit can be treated with pedicle screw fixation only without decompression or fusion.

Therapy of AF system inside and outside after joint vertebral bone fusion treatment on thoracolum-bar burst fracture / 中国医师杂志

Objective To explore the clinical curative effect of AF system combined vertebra re-duction and posterolateral bone fusion treatment thoracolumbar burst fracture .Methods Seventeen pa-tients with thoracolumbar burst fracture using period stage , according to the system of AF clinical symptoms and image data line pressure decreased , and the pressure or not to hurt inside the vertebral pedicle autoge-nous bone grafts are grain filling and vertebral posterolateral line between the axon , lamina around small joints and bone , and postoperative follow-up X-ray inspection regularly , observe internal fixation and verte-bral vertebral height and adjacent intervertebral space changes , or after fixation and reset lost .Results following up 13 months, vertebral body height restore and maintain good , bolt looseness and broken and ver-tebral body height complications such as lost were no found in 17 cases.Conclusion Treatments of Poste-rior fixation combined short stage AF vertebral body and posterolateral bone fusion on thoracolumbar burst fracture are not only rebuild the vertebral height , but also make the vertebral obtained after three pillars in stable, reduce the internal fixation and compressed vertebral again such complications .

Comparison of Bony Fusion Between the Hollow Cage Group and the Cage with Bone Substitutes Group in One-level Cervical Spinal Disorders

OBJECTIVE: The aim of this study was to assess the clinical outcomes and bone fusion rates after insertion of hollow cages or cages with bone substitutes for treatment of disc protrusion in the cervical spine. METHODS: We performed a retrospective review of 93 patients who had undergone cage-assisted anterior cervical spine fusion. Patients were treated with hollow cages (N=52) or with cages with bone substitutes (N=41). Initial and follow up radiologic data were analyzed using Vavruch bone fusion criteria. RESULTS: Clinical outcomes including preoperative and postoperative pain and functional scores were not significantly different between the two patient groups. The over-all fusion rates differed between the two groups: patients treated with hollow cages demonstrated an average fusion rate of 84.6%, while patients treated with cages with bone substitutes demonstrated an average fusion rate of 87.8%, but these differences were not significant 24 months after surgery. At 18 months after surgery, the fusion rates of patients treated with cages with bone substitutes were significantly different from those of patients treated with hollow cages. Among patients who received bone substitutes, patients who received DBM exhibited better fusion outcomes than patients treated with other bone materials after 18 months of follow-up. CONCLUSION: Patients who are surgically treated with anterior cervical spine fusion for disc protrusion using cages with bone substitutes may achieve earlier fusion than patients treated with hollow cages, although both groups show similar final fusion rates.

Treatment choices for unilateral cervical facet locking / 中华创伤杂志

Objective To explore different treatment choices for unilateral cervical facet locking. Methods The study involved 32 patients with cervical unilateral facet locking. Successful reduction by the skull traction was done in eight patients, of whom three were fixated by the head and neck chest plas-ter after a month of traction. Five patients were treated with anterior decompression and internal fusion fixation. The other 23 patients resulted in failure of traction and then were treated with anterior reduction, discectomy and internal fusion fixation in 14 patients, subtotal vertebral decompression and bone graft fix-ation in three, posterior open reduction and anterior bone graft fixation in one, posterior reduction, fixation and internal fusion fixation in three and posterior reduction and decompression plus anterior discectomy decompression and bone graft fixation in two. Due to misdiagnosis, one patient was treated with anterior decompression and fusion eight months after injury. Results A follow-up for average 18 months showed cervical instability in two patients who were treated with only traction, without fusion. The patients treated with anterior cervical fusion obtained bone union after 12 weeks, with satisfactory cervical physiological curvature and vertebral height. There were no internal fixation complications or neurological complications. Conclusions The treatment of lower cervical unilateral facet locking needs a compre-hensive considerations on whether there associates with disc injury, posterior column fractures or spinal cord injuries. As for patients with lower cervical unilateral facet locking combined with traumatic cervical disc herniation, the anterior reduction and decompression is the choice of treatment. While for those with-out disc herniation, traction or posterior open reduction and fixation can be carried out directly.

Clinical Results of Anterior Cervical Discectomy and Fusion with Prefilled Cage in Patient with Traumatic Cervical Injury

OBJECTIVES: This study is designed to evaluate the fusion rate of anterior cervical discectomy and fusion (ACDF) using prefilled cage, and clinical features in patients with traumatic cervical injury. METHODS: Sixteen trauma patients at a single institute who underwent ACDF with prefilled cage and rigid plate fixation were evaluated for radiographic fusion status postoperatively every 1 month, 3 month, and 6 month after the surgery. ACDFs were done in 9 patients at one level, 3 patients at two levels, 3 patients at three levels, and 1 patient at four levels. Fourteen patients had fracture and instability, and 2 patients had traumatic herniated cervical discs without fracture and instability. Plain radiographs and CT scan were done for evaluation of bone fusion in all patients. RESULTS: Bone fusion was recognized in all patients. Intervertebral disc height was well maintained during follow-up period. There was no patient with graft failure and instability. Even though the patients with fracture and instability, there was no patient who needed posterior stabilization. There was one case of subsidence without clinical symptom which was needed additional surgical treatment. CONCLUSION: In the treatment of the patients with traumatic cervical diseases, prefilled cage is very effective to achieve cervical spinal stability after ACDF, and to maintain intervertebral disc height. We can achieve immediate postoperative stability and prevent graft displacement by reinforcement with cervical plate and screws.

The use of hydroxyapatite for arthrodesis in dogs and cats: a clinical study

Twenty-five arthrodeses were performed in four cats and 17 dogs using synthetic hydroxyapatite as fresh autogenous graft cancellous bone substitute. Arthrodesis was performed in the carpal joint in eight cases, in the tarsal joint in 10, in the elbow joint in six, and in the knee joint in one case. The mean radiographic follow-up time was 30 days in one animal, 45 days in another animal and 60 days in the 19 remaining cases. Bone union was observed in 24 arthrodeses. Non-union of one elbow arthrodesis was due to failure of stabilization. Restoration of limb functionality was classified as good to excellent in 22 cases. Hydroxyapatite was able to promote bone growth and is suitable for using in routine surgical procedures for small animals

Realizaram-se 25 artrodeses em 21 casos, quatro em gatos e 17 em cães, utilizando hidroxiapatita sintética como substituto ao enxerto ósseo autógeno esponjoso fresco, sendo oito na articulação do carpo, 10 na articulação do tarso, seis na do cotovelo e uma na do joelho. As avaliações radiográficas foram realizadas aos 30 dias em um animal, aos 45 dias em outro e aos 60 dias nos 19 casos restantes. Visibilizou-se união óssea em 24 artrodeses e a não-união em um cotovelo foi atribuída a falha na estabilização. O retorno à função do membro foi classificado de bom a excelente em 22 casos. A hidroxiapatita foi capaz de viabilizar o crescimento ósseo e mostrou-se factível para utilização na prática cirúrgica rotineira em pequenos animais

A Comparative Experimental Study of Allograft andPorous Hydroxyapatite as Bone Substitutes / 대한정형외과학회잡지

PURPOSE: An experimental animal study was performed to compare the bone fusion capacity of an allograft and porous hydroxyapatite. MATERIALS AND METHODS: Three milliliters of allograft or porous hydroxyapatite particles were inserted between the 4th and 5th lumbar transverse processes of New Zealand white rabbits weighing 3-3.5 kg. The total number of rabbits was 30, which were divided randomly into 2 groups. The bone formation and fusion capacity were evaluated 12 weeks after surgery through the gross findings and manual palpation, as well as radiological, biomechanical, and histological studies. Six rabbits in the allograft group died during breeding but the autopsy finding did not show any evidence suggesting an infection or graft rejection. The allograft was harvested from the iliac crest of the rabbits of the same species aseptically and was preserved at ??80oC for at least 7 days before implantation. RESULTS: The fusion rates were 55.6% (5/9) and 66.7% (10/15) in the allograft and porous hydroxyapatite groups, respectively. The mean values of the tensile strengths were 140.7 N in the allograft group and 189.6 N in the porous hydroxyapatite group. Histological analysis of 2 specimens from each group revealed theporous hydroxyapatite group to show a slightly better osteoconduction capacity. CONCLUSION: The porous hydroxyapatite group showed better bony union capacity even though there was no significant difference between the 2 groups.

Short-term Results of Anterior Cervical Fusion with Cylindrical Cage(AMSLU(TM))

OBJECTIVE: The AMSLU(TM) cage is a newly developed instrument, that utilizes concept of the key-stone graft in posterior lumbar interbody fusion. The authors try to prove the short-term efficacy of AMSLU(TM) cage in surgical treatment of degenerative cervical disc disease. METHODS: We investigate clinical and radiological features of 24 patients who underwent anterior cervical fusion with AMSLU(TM) cage during the period between January 2001 and February 2002. Clinical and radiological results were assessed by using Odom's criteria and regular follow-up of radiographs, respectively. RESULTS: All patients included in this study had been followed by at least 6 months. Except 3 patients, all patients underwent single-level operation, and among remaining 21 patients, C5-6 was the most commonly involved level (17 cases). Symptomatic improvement was found in 22 cases (91%). Evidence of bone fusion was invariably found by the end of the postoperative 6 months in every case and increase of disc height was also shown in all patients. Neither operation-related nor instrument-related complications was seen. CONCLUSION: Anterior cervical fusion with AMSLU(TM) cage has several advantages over the preexisting instruments, such as easy maneurability, avoidance of donor site complications, and anatomical contour which renders it to endure lateral shearing force and its relatively large contact area.

Clinical Analysis of Posterior C1-C2 Fusion for Atlantoaxial Instability

The authors analyzed the surgical results of posterior C1-C2 fusion in 18 cases of atlantoaxial instability. Posterior C1-C2 wiring with bone fusion(11 cases), C1-C2 transarticular screw fixation(6 cases), and occipitocervical fusion(1 case) have been performed for unstable odontoid process fractures(10 cases), transverse ligament injury(4 cases), os odontoideum(3 cases), rheumatoid C1-2 instability(1 case). Follow-up examination was performed in all patientts after a mean postoperativeduration of 39.9 months. Follow-up x-rays showed successful stabilization in 17 cases(94%). Postoperative neurological evaluation showed improvement in 16 cases(89%), stabilization in 2 cases(11%) and there was no major operative complication.

Clinical Analysis of Bone Fusion for Spinal Stenosis with and without Instrumentation

Spinal stenosis has several types of etiology such as degenerative, spondylolisthetic and postoperative, etc. Operative management for spinal stenosis is adequate decompression and stabilization of the unstable lumbar spine created by the decompressive procedure. We analysed 52 operative cases of spinal stenosis delete from January 1994 to October 1996. The following results were obtained 1) The male and female ratio was 1:1.9 and mean age was 52.1 years old 2) Mean follow-up period was 20.3 months 3) The involved site was one level in(28)(53.9%), two level in(19)(36.5%), and three levels in(5)(9.6%) 4) For decompression method, total laminectomy combined with foraminotomy and facetectomy was employed procedure. 5) For stabilization, bilateral posterolateral fusion was performed in major damaged facet joint and transverse process. Instrumentation was combined in 61.5% delete of all cases 6) According to the criteria of Kirkaldy-willis, excellent and good results were shown in 90.6% of fused group with instrumentation and 85% of fused group without instrumentation.

A Clinical Analysis of Surgically Managed Tuberculous Spondylitis

Fourty three patients with tuberculous spondylitis were surgically treated through the anterior approach at our hospital from January, 1989 to December, 1994. Among them, 32 cases were followed up more than 18 months postoperatively, and were included in this study. The most prevalent location was lumbar region(50%). Paraparesis was frequently seen in patients with middle and lower thoracic spinal lesions and all patients with neurologic deficits improved after decompression of spinal cord. Autogenous rib and/or iliac strut bone grafting was performed, followed by spinal instrumentation. Solid bone fusion was obtained in all patients. There was no need for prolongation of duration of antituberculous drug therapy and no increased incidence of secondary infection due to spinal instrumentation.