The presence of HBsAg and anti-HBs was demonstrated in 62.2 and 32.2 % respectively of 90 Black A... more The presence of HBsAg and anti-HBs was demonstrated in 62.2 and 32.2 % respectively of 90 Black African people suffering from cirrhosis, and the presence of HBeAg and anti-HBe in 25.6 and 41.1%, respectively. These results do not differ from those observed in patients suffering from primary hepatoeellular carcinoma.
The authors reviewed 817 instrumented lumbosacral fusions in adults and found an incidence of 3.2... more The authors reviewed 817 instrumented lumbosacral fusions in adults and found an incidence of 3.2% deep wound infections. The primary focus of this study was the management of these infections, with particular attention to whether the implants needed to be removed. A consulting infectious disease specialist indicated that an acute infection of a low back fusion wound could not be healed without removal of the metallic implants. This opinion was in contrast to the authors' daily experience and prompted this study. The authors identified and reviewed 817 cases of instrumented posterior lumbosacral arthrodeses in adults. A detailed analysis of any case with a deep wound infection was performed and yielded and infection rate of 3.2% (26 patients). Of these, 24 achieved a clean, closed wound without removal of instrumentation through a protocol of aggressive debridement and secondary closure. Instrumentation removal is not necessary to obtain a clean, closed wound using an aggressive...
The Spine Journal, Volume 3, Issue 5, Pages 67-68, September 2003, Authors:James MacDougall; Jose... more The Spine Journal, Volume 3, Issue 5, Pages 67-68, September 2003, Authors:James MacDougall; Joseph Perra, MD; Manuel Pinto, MD; James Schwende, MD; Ensor Transfeldt, MD; Francis Denis, MD; Timothy Garvey; James Ogilvie; Jill Wroblewski. ...
Journal of orthopaedics and traumatology : official journal of the Italian Society of Orthopaedics and Traumatology, 2009
The lack of a widely available scoring system for cervical degenerative spondylosis encouraged th... more The lack of a widely available scoring system for cervical degenerative spondylosis encouraged the authors to establish and validate a systematic quantitative radiographic index. This study included intraobserver and interobserver reliability testing among three reviewers with different years of experience. Each observer independently scored four cervical radiographs of 48 patients at separate intervals, and statistical analysis of the grading was performed. There was high intraobserver and interobserver reliability between the two experienced observers. There was fair reliability between the less experienced observer and the more experienced observers. The cervical degenerative index appears to be a reliable and reproducible radiographic assessment of cervical spondylosis. The index will have direct applicability for longitudinal study of cervical spondylosis and may be clinically relevant as well.
Degenerative de novo scoliosis is commonly present in older adult patients with spinal pain. The ... more Degenerative de novo scoliosis is commonly present in older adult patients with spinal pain. The degenerative process including disc bulging, facet arthritis, and ligamentum flavum hypertrophy contributes to the appearance of symptoms of spinal stenosis in these patients. The etiology, prevalence, biomechanics, classification, symptomatology, and treatment of degenerative lumbar scoliosis in association with spinal stenosis are reviewed. Review study. Retrospective analysis of studies focused on all parameters concerning degenerative scoliosis associated with stenosis. There is a variety of treatment methods of degenerative scoliosis based on symptomatology and radiologic measurements of scoliosis and stenosis. Satisfactory clinical results reported in relevant retrospective studies after operative treatment range from 83% to 96% but with increased percentage of complications. An algorithm for operative treatment corresponding to a newly proposed classification system of degenerative lumbar scoliosis with associated canal stenosis is presented. There is an increasing prevalence of degenerative scoliosis in the aged population. Even though the exact percentage of patients with symptomatology of spinal stenosis is not known, the main goal is to provide pain relief and improved functional lifestyle with minimum intervention.
This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presen... more This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presenting with scoliosis at a single institution, as related to their spinal (C7 plumbline) and global (gravity line) balance. To assess the influence of sagittal and coronal balance on HRQOL in adult scoliosis. Many surgeons believe that achieving adequate spinal balance is important in the management of adult spinal deformity, but the evidence supporting this concept remains limited. A previous study has found weak correlations between sagittal spinal balance and HRQOL in adult spinal deformity, but this finding has never been confirmed independently. In addition, although the use of the gravity line is gaining interest in the evaluation of global balance, it remains unknown if this parameter is associated with HRQOL. During a 1-year period, 73 consecutive new patients presenting with unoperated adult scoliosis and requiring full spine standing radiographs were evaluated using a force plate in order to simultaneously assess the gravity line. All patients also completed the Oswestry Disability Index (ODI) questionnaire to assess the HRQOL. Spinal balance was evaluated from the C7 plumbline and global balance from the gravity line, respectively. C7 plumbline and gravity line were both assessed with respect to the posterosuperior corner of the S1 vertebral body and central sacral vertebral line in the sagittal and coronal plane, respectively. C7 plumbline and gravity line, as well as their relative position, were correlated with the ODI, using Spearman coefficients. Sagittal spinal (C7 plumbline) and global (gravity line) balance, as well as their relative position were significantly related to the ODI. A poor ODI (>34) was associated with a sagittal C7 plumbline greater than 6 cm, a sagittal gravity line greater than 6 cm, and a C7 plumbline in front of the gravity line. Correlations between coronal balance and the ODI were not statistically significant. Sagittal spinal and global balance was strongly related to the ODI in adults with scoliosis. The observed correlation coefficients were higher than those reported in the only previous study suggesting the detrimental association of positive sagittal balance on ODI in adult spinal deformity. Coronal spinal and global balance did not influence the ODI in the current study cohort. Thisstudy underlines the relevance of C7 plumbline and gravity line in the evaluation of spinal and global balance, and lends further support to the philosophy of achieving adequate sagittal balance in the management of adult spinal deformity, especially in patients older than 50 years old with degenerative scoliosis.
Prospective and retrospective outcome analysis following arthrodesis for adult isthmic spondyloli... more Prospective and retrospective outcome analysis following arthrodesis for adult isthmic spondylolisthesis in 31 patients. To examine whether or not patients having such surgery have a functional improvement in their lives. The literature is full of articles concerning adolescent spondylolisthesis, the union rate for adult spondylolisthesis, the ability to reduce deformities, and the outcome of surgery for degenerative spondylolisthesis, but very scant on the postoperative functional outcome of adults with isthmic spondylolisthesis. Functional outcome was analyzed by both preoperative and postoperative SF-36 questionnaires and by four additional functional questionnaires at follow-up. Statistically significant improvement was seen in six of the eight SF-36 scales. Fifty-five percent of the patients scored in the normal range at follow-up compared with none before surgery. Significant functional improvement was seen following surgical arthrodesis of the painful segments in adults with isthmic spondylolisthesis (P = 0.001). This study further confirms that such surgery is appropriate for patients failing adequate nonoperative treatment.
The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive ad... more The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive adult patients with spondylolisthesis. Two factors significantly improved fusion rate: combined anterior and posterior fusion and rigid postoperative immobilization in the cast. In 65 patients with isthmic spondylolisthesis, the fusion rate was raised from 70% when posterior fusion alone was used to 88% when combined anterior and posterior fusion was used. In 20 patients with degenerative spondylolisthesis, frequent use of combined anterior and posterior fusion contributed to a high overall fusion rate of 95%. Among patients with isthmic spondylolisthesis, postoperative cast immobilization resulted in a higher fusion rate of 90% compared with a fusion rate of 63% obtained after brace immobilization.
A retrospective review of 1223 thoracic and lumbar anterior spinal fusions was performed from 196... more A retrospective review of 1223 thoracic and lumbar anterior spinal fusions was performed from 1969 through 1992. To document the incidence and specific types of perspective complications related to anterior spinal fusions. Despite the increased use of anterior spinal surgery, there has been little documentation of the specific types and frequencies of the complications associated with its use. All Minnesota Spine Center patients age 18 years or older who had anterior spinal fusions between the levels of T1 and S1 from August 1969 to June 1992 were reviewed for the occurrence of perioperative complications. Surgical approach and technique and associated comorbidity was recorded. The risk of a complication was increased for patients over age 60 years, for women, and for patients with multiple preexisting health problems. Serious complications, such as death (0.3%), paraplegia (0.2%), and deep wound infection (0.6%) were rare. The complication rate for complications that were directly attributed to the anterior spinal surgery was 11.5%. Anterior spinal fusion surgery is a safe procedure and can be used with confidence when the nature of a patient's spinal disorder dictates its use. Complications are often approach specific.
True back pain is uncommon in children and adolescents. The authors report a case of scoliosis as... more True back pain is uncommon in children and adolescents. The authors report a case of scoliosis associated to osteoblastoma in a very unusual site--the rib. This particular location was reviewed in the literature and appears to have an incidence of 0.41% as compared with osteoid osteomas and osteoblastomas in general. The case reported was a 14-year-old girl presenting with a 32 degree scoliosis that reduced to 9 degrees after excision of the lesion. The authors recommend personal review of bone scans as poor communication between the orthopedic surgeon and the isotope expert may make an osteoblastoma be interpreted as a radiographic artifact.
Retrospective case review at a single center. To analyze the incidence and risk factors associate... more Retrospective case review at a single center. To analyze the incidence and risk factors associated with proximal junctional kyphosis (PJK) and distal junctional kyphosis (DJK) in patients undergoing instrumented spinal fusion for Scheuermann kyphosis. Previously reported risk factors for junctional kyphosis include improper end vertebrae selection, curve correction greater than 50%, or excessive junctional soft tissue dissection. Clinical and radiographic data on 67 patients (mean age 37) from a single center treated with instrumented fusion for Scheuermann kyphosis were reviewed. All patients had complete radiographic data with a minimum 5-year follow-up (mean: 73 months). Abnormal PJK was defined by a proximal junctional angle greater than 10 degrees and at least 10 degrees greater than the corresponding preoperative measurement. DJK was similarly defined between the caudal endplate of the lower instrumented vertebra to the caudal endplate that was 1 vertebra below. The incidence of PJK as defined above was seen in 20 patients (30%). The development of PJK was associated with failure to incorporate the proximal end vertebra (15 patients), disruption of junctional ligamentum flavum (3 patients), or combination of both (2 patients). The most common cause of inappropriate end vertebra selection was poor visualization of the upper thoracic vertebra.DJK occurred in 8 patients (12%) and 7 of them had fusion short of including the first lordotic disc. The incidence of PJK can be minimized by the appropriate selection of the upper end vertebra to be fused and avoiding disruption of the junctional ligamentum flavum. The development of DJK can be minimized by incorporation of the first lordotic disc into the fusion construct.
A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis ... more A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis with fusion from T10 or higher to S1. To document the perioperative and long-term complications and instrumentation problems, and to attempt to determine variables which may influence these problems. It is not a study of curve correction, balance, or functional outcome. Several previous studies from this and other centers have shown a relatively high complication rate for this select group of patients. Various fusion techniques (anterior, posterior, autograft, allograft), various instrumentation techniques, and various immobilization techniques have created confusion as to the best methodology to employ. Minimal 2-year follow-ups have been standard, but longer follow-ups have shown additional problems. The study cohort consisted of 50 adult patients from a single center who had undergone corrective scoliosis surgery from T10 or higher to the sacrum and who had at least a 5-year minimum follow-up. The mean age was 54 years (range, 18-72), and the mean follow-up was 9.7 years (range, 5-26). All radiographs, office charts, and hospital charts were combed by an independent investigator for complications, which were divided into major and minor, as well as early, intermediate and late. The curvature values and corrections were the subject of a different article, and were not included in this study. There were no deaths or spinal cord injuries. Six patients had nerve root complications, 4 of which totally recovered. Pseudarthrosis was seen in 24% of the patients, only 25% of which were detected within the 2-year follow-up period. Pseudarthrosis was most common at the lumbosacral level. There was no statistical difference in the pseudarthrosis rate between patients with sacral-only fixation versus iliac fixation. Painful implants requiring removal were noted in 11 of the 50 patients. Long fusions to the sacrum in adults with scoliosis continue to have a high complication rate. As compared to the original publications in the 1980s (Kostuik and Hall, Spine 1983;8:489-500; Balderston et al, Spine 1986;11:824-9) the more recent articles have shown a reduction, but not elimination of the pseudarthrosis problem using segmental instrumentation and anterior fusion of the lumbar spine coupled with structural interbody grafting at L4-L5 and L5-S1. Two-year follow-up is inadequate as pseudarthrosis and painful implants often are detected later. Only 3 of the 12 patients with pseudarthrosis were detected within the first 2 years after surgery.
Retrospective study of patients after extension of previous scoliosis fusions to the pelvis. To d... more Retrospective study of patients after extension of previous scoliosis fusions to the pelvis. To determine whether modern instrumentation and surgical techniques provide for increased fusion rates with fewer complications. Traditionally, long fusions to the pelvis in adults with idiopathic scoliosis have resulted in high complication rates, including pseudarthrosis. The hospital and clinic charts of 41 patients (40 female, 1 male) were reviewed 41 months (range: 24-116) after surgery for extension to the pelvis of previous scoliosis fusions. Thirty-nine of 41 had a combined anteroposterior fusion extension; two had posterior extension only. In 37 of 41 patients, Cotrel-Dubousset (CD) instrumentation was used; in two, Isola (Acromed Corp., Cleveland, OH), in one, TSRH; (Sofamor-Danek, Memphis, TN), and in one, Synergy (Cross Medical Products, Columbus, OH). Parameters analyzed were fusion rate, sagittal and coronal balance, lumbar lordosis, length of fusion extension, and distal fixation method. Complications were seen in 30 of 41 patients. The pseudarthrosis rate was 37% (15/41) and was significantly related to the method of distal posterior fixation. With sacral fixation only, the rate was 53% (8/15), with iliac fixation only 42% (3/7), and with both iliac and sacral fixation 21% (4/19; P < 0.05). This was not correlated with fusion rate, and the length of fusion extension did not affect the pseudarthrosis rate or sagittal balance. When fixed to the ilium and sacrum, modern instrumentation appears capable of maintaining sagittal balance with lower rates of pseudarthrosis when previous scoliosis fusions are extended to the pelvis. The complication rate remains significant.
Objective To define the origin of radiculopathy of patients with degenerative lumbar scoliosis an... more Objective To define the origin of radiculopathy of patients with degenerative lumbar scoliosis and to assess the correlation between percentage of radiculating pain relief with selective nerve root injections and lateral canal dimensions. Methods Ninety-three consecutive ...
The purpose is to define the origin of radiculopathy of patients with degenerative lumbar scolios... more The purpose is to define the origin of radiculopathy of patients with degenerative lumbar scoliosis-stenosis and to assess the correlation between percentage of initial radicular leg pain relief with selective nerve root injections and lateral canal dimensions. Retrospective clinical study. Thirty-six consecutive patients (average age 72) from Twin Cities Spine Center with degenerative lumbar scoliosis (average major curve 25°) and radicular symptoms were studied. Patients underwent 46 selective steroid injections of nerve roots concordant with clinical symptomatology. Radiographic measurements included major and lumbosacral curve Cobb angle. Computerized measurements of magnetic resonance imaging (MRI) included minimum subarticular height and foramen cross-sectional area of the nerve roots that were injected. Initial response from the nerve root injections was also rated. Twenty-five percent of nerve root symptoms were coming from the major curve, 72.2% from the lumbosacral hemicurve and 2.8% from both (P<0.001). The affected nerve roots were more frequently the L4 (34.8%) and L5 (28.3%) nerve roots. A total of 71.7% of radicular symptoms were originating from the concavity of the curve and 28.7% from the convexity (P<0.001). The relief from injections was more than 50% in 75% of the patients at 15 days postinjection. There was no statistical significant correlation (P>0.05) between the lateral canal dimensions and the initial response to injection of anesthetic plus steroid injection. In degenerative lumbar scoliotic curves, radicular symptoms are attributed mainly to nerve roots exiting from the concavity of the lumbosacral hemicurve. No evidence was found that the rate of initial relief from selective nerve root injections correlates with the degree of stenosis noted in the MRI.
The objective of this study is to evaluate the effectiveness of a specific methodology for plain ... more The objective of this study is to evaluate the effectiveness of a specific methodology for plain radiographic assessment of lumbar pedicle screw position. To evaluate the effectiveness of using orthogonal plain radiographs and a systematic method of interpretation, developed by the senior author, in assessing the placement of lumbar and lumbosacral pedicle screws. This was an adult cadaver study of the accuracy of using plain radiographs or computed tomography to assess pedicle screw position. Plain radiographs were performed and compared with computed tomography (CT) scans. Gross anatomic dissections were performed to directly confirm screw position. Variables, including screw material, radiographic view, and screw dimensions, were assessed for their effect on the ability of physicians to determine pedicle screw position. Multiple readers were included in the study, including 1 spine Fellow, 3 experienced orthopedic spine surgeons, and 1 neuroradiologist. Five adult cadaveric spines were instrumented with titanium pedicle screws from L1 to S1. Screws were placed outside the confines of the pedicle in all 4 quadrants or within the pedicle using a Latin-Square design. Each cadaver was imaged with orthogonal radiographs and high-resolution CT scans. The spines were then reimaged after the instrumentation was replaced with stainless steel screws placed in the identical position. Finally, each spine was dissected to assess the exact position of the screws. Images were read in a blinded fashion by 1 spine fellow, 2 staff surgeons, and a staff radiologist. The results were compared with the known screw positions at dissection. In total, 120 pedicle screws were placed, 44 (38%) outside the confines of the pedicle. Sensitivity, defined as the percent of the misplaced screws that were correctly identified, was similar across the 3 diagnostic tests, but markedly improved when all CT formats were considered together. Similarly, specificity, defined as the percent of screws correctly read as being placed within the pedicle, was independent of radiographic examination. Sensitivity of the radiographic technique was 70.1% and specificity was 83.0%, whereas sensitivity for CT scans was 84.7% and specificity was 89.7%. There was an observed association with anatomic level, with a consistently less accuracy in detecting screw position at L1 with plain x-ray (P=0.001). Additionally, correct position of stainless steel screws was more difficult to detect as compared with titanium (P=0.033) using either x-rays or CT. Other variables examined, such as screw length and screw diameter, did not have an effect on the ability to read the positioning. CT scans, often considered the "gold standard" for clinical assessment of pedicle screw placement, have limitations when validated with gross anatomical dissection. The described systematic method for evaluating pedicle screw placement using orthogonal plain radiographs attained accuracy comparable to high-resolution CT scans.
The presence of HBsAg and anti-HBs was demonstrated in 62.2 and 32.2 % respectively of 90 Black A... more The presence of HBsAg and anti-HBs was demonstrated in 62.2 and 32.2 % respectively of 90 Black African people suffering from cirrhosis, and the presence of HBeAg and anti-HBe in 25.6 and 41.1%, respectively. These results do not differ from those observed in patients suffering from primary hepatoeellular carcinoma.
The authors reviewed 817 instrumented lumbosacral fusions in adults and found an incidence of 3.2... more The authors reviewed 817 instrumented lumbosacral fusions in adults and found an incidence of 3.2% deep wound infections. The primary focus of this study was the management of these infections, with particular attention to whether the implants needed to be removed. A consulting infectious disease specialist indicated that an acute infection of a low back fusion wound could not be healed without removal of the metallic implants. This opinion was in contrast to the authors' daily experience and prompted this study. The authors identified and reviewed 817 cases of instrumented posterior lumbosacral arthrodeses in adults. A detailed analysis of any case with a deep wound infection was performed and yielded and infection rate of 3.2% (26 patients). Of these, 24 achieved a clean, closed wound without removal of instrumentation through a protocol of aggressive debridement and secondary closure. Instrumentation removal is not necessary to obtain a clean, closed wound using an aggressive...
The Spine Journal, Volume 3, Issue 5, Pages 67-68, September 2003, Authors:James MacDougall; Jose... more The Spine Journal, Volume 3, Issue 5, Pages 67-68, September 2003, Authors:James MacDougall; Joseph Perra, MD; Manuel Pinto, MD; James Schwende, MD; Ensor Transfeldt, MD; Francis Denis, MD; Timothy Garvey; James Ogilvie; Jill Wroblewski. ...
Journal of orthopaedics and traumatology : official journal of the Italian Society of Orthopaedics and Traumatology, 2009
The lack of a widely available scoring system for cervical degenerative spondylosis encouraged th... more The lack of a widely available scoring system for cervical degenerative spondylosis encouraged the authors to establish and validate a systematic quantitative radiographic index. This study included intraobserver and interobserver reliability testing among three reviewers with different years of experience. Each observer independently scored four cervical radiographs of 48 patients at separate intervals, and statistical analysis of the grading was performed. There was high intraobserver and interobserver reliability between the two experienced observers. There was fair reliability between the less experienced observer and the more experienced observers. The cervical degenerative index appears to be a reliable and reproducible radiographic assessment of cervical spondylosis. The index will have direct applicability for longitudinal study of cervical spondylosis and may be clinically relevant as well.
Degenerative de novo scoliosis is commonly present in older adult patients with spinal pain. The ... more Degenerative de novo scoliosis is commonly present in older adult patients with spinal pain. The degenerative process including disc bulging, facet arthritis, and ligamentum flavum hypertrophy contributes to the appearance of symptoms of spinal stenosis in these patients. The etiology, prevalence, biomechanics, classification, symptomatology, and treatment of degenerative lumbar scoliosis in association with spinal stenosis are reviewed. Review study. Retrospective analysis of studies focused on all parameters concerning degenerative scoliosis associated with stenosis. There is a variety of treatment methods of degenerative scoliosis based on symptomatology and radiologic measurements of scoliosis and stenosis. Satisfactory clinical results reported in relevant retrospective studies after operative treatment range from 83% to 96% but with increased percentage of complications. An algorithm for operative treatment corresponding to a newly proposed classification system of degenerative lumbar scoliosis with associated canal stenosis is presented. There is an increasing prevalence of degenerative scoliosis in the aged population. Even though the exact percentage of patients with symptomatology of spinal stenosis is not known, the main goal is to provide pain relief and improved functional lifestyle with minimum intervention.
This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presen... more This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presenting with scoliosis at a single institution, as related to their spinal (C7 plumbline) and global (gravity line) balance. To assess the influence of sagittal and coronal balance on HRQOL in adult scoliosis. Many surgeons believe that achieving adequate spinal balance is important in the management of adult spinal deformity, but the evidence supporting this concept remains limited. A previous study has found weak correlations between sagittal spinal balance and HRQOL in adult spinal deformity, but this finding has never been confirmed independently. In addition, although the use of the gravity line is gaining interest in the evaluation of global balance, it remains unknown if this parameter is associated with HRQOL. During a 1-year period, 73 consecutive new patients presenting with unoperated adult scoliosis and requiring full spine standing radiographs were evaluated using a force plate in order to simultaneously assess the gravity line. All patients also completed the Oswestry Disability Index (ODI) questionnaire to assess the HRQOL. Spinal balance was evaluated from the C7 plumbline and global balance from the gravity line, respectively. C7 plumbline and gravity line were both assessed with respect to the posterosuperior corner of the S1 vertebral body and central sacral vertebral line in the sagittal and coronal plane, respectively. C7 plumbline and gravity line, as well as their relative position, were correlated with the ODI, using Spearman coefficients. Sagittal spinal (C7 plumbline) and global (gravity line) balance, as well as their relative position were significantly related to the ODI. A poor ODI (>34) was associated with a sagittal C7 plumbline greater than 6 cm, a sagittal gravity line greater than 6 cm, and a C7 plumbline in front of the gravity line. Correlations between coronal balance and the ODI were not statistically significant. Sagittal spinal and global balance was strongly related to the ODI in adults with scoliosis. The observed correlation coefficients were higher than those reported in the only previous study suggesting the detrimental association of positive sagittal balance on ODI in adult spinal deformity. Coronal spinal and global balance did not influence the ODI in the current study cohort. Thisstudy underlines the relevance of C7 plumbline and gravity line in the evaluation of spinal and global balance, and lends further support to the philosophy of achieving adequate sagittal balance in the management of adult spinal deformity, especially in patients older than 50 years old with degenerative scoliosis.
Prospective and retrospective outcome analysis following arthrodesis for adult isthmic spondyloli... more Prospective and retrospective outcome analysis following arthrodesis for adult isthmic spondylolisthesis in 31 patients. To examine whether or not patients having such surgery have a functional improvement in their lives. The literature is full of articles concerning adolescent spondylolisthesis, the union rate for adult spondylolisthesis, the ability to reduce deformities, and the outcome of surgery for degenerative spondylolisthesis, but very scant on the postoperative functional outcome of adults with isthmic spondylolisthesis. Functional outcome was analyzed by both preoperative and postoperative SF-36 questionnaires and by four additional functional questionnaires at follow-up. Statistically significant improvement was seen in six of the eight SF-36 scales. Fifty-five percent of the patients scored in the normal range at follow-up compared with none before surgery. Significant functional improvement was seen following surgical arthrodesis of the painful segments in adults with isthmic spondylolisthesis (P = 0.001). This study further confirms that such surgery is appropriate for patients failing adequate nonoperative treatment.
The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive ad... more The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive adult patients with spondylolisthesis. Two factors significantly improved fusion rate: combined anterior and posterior fusion and rigid postoperative immobilization in the cast. In 65 patients with isthmic spondylolisthesis, the fusion rate was raised from 70% when posterior fusion alone was used to 88% when combined anterior and posterior fusion was used. In 20 patients with degenerative spondylolisthesis, frequent use of combined anterior and posterior fusion contributed to a high overall fusion rate of 95%. Among patients with isthmic spondylolisthesis, postoperative cast immobilization resulted in a higher fusion rate of 90% compared with a fusion rate of 63% obtained after brace immobilization.
A retrospective review of 1223 thoracic and lumbar anterior spinal fusions was performed from 196... more A retrospective review of 1223 thoracic and lumbar anterior spinal fusions was performed from 1969 through 1992. To document the incidence and specific types of perspective complications related to anterior spinal fusions. Despite the increased use of anterior spinal surgery, there has been little documentation of the specific types and frequencies of the complications associated with its use. All Minnesota Spine Center patients age 18 years or older who had anterior spinal fusions between the levels of T1 and S1 from August 1969 to June 1992 were reviewed for the occurrence of perioperative complications. Surgical approach and technique and associated comorbidity was recorded. The risk of a complication was increased for patients over age 60 years, for women, and for patients with multiple preexisting health problems. Serious complications, such as death (0.3%), paraplegia (0.2%), and deep wound infection (0.6%) were rare. The complication rate for complications that were directly attributed to the anterior spinal surgery was 11.5%. Anterior spinal fusion surgery is a safe procedure and can be used with confidence when the nature of a patient's spinal disorder dictates its use. Complications are often approach specific.
True back pain is uncommon in children and adolescents. The authors report a case of scoliosis as... more True back pain is uncommon in children and adolescents. The authors report a case of scoliosis associated to osteoblastoma in a very unusual site--the rib. This particular location was reviewed in the literature and appears to have an incidence of 0.41% as compared with osteoid osteomas and osteoblastomas in general. The case reported was a 14-year-old girl presenting with a 32 degree scoliosis that reduced to 9 degrees after excision of the lesion. The authors recommend personal review of bone scans as poor communication between the orthopedic surgeon and the isotope expert may make an osteoblastoma be interpreted as a radiographic artifact.
Retrospective case review at a single center. To analyze the incidence and risk factors associate... more Retrospective case review at a single center. To analyze the incidence and risk factors associated with proximal junctional kyphosis (PJK) and distal junctional kyphosis (DJK) in patients undergoing instrumented spinal fusion for Scheuermann kyphosis. Previously reported risk factors for junctional kyphosis include improper end vertebrae selection, curve correction greater than 50%, or excessive junctional soft tissue dissection. Clinical and radiographic data on 67 patients (mean age 37) from a single center treated with instrumented fusion for Scheuermann kyphosis were reviewed. All patients had complete radiographic data with a minimum 5-year follow-up (mean: 73 months). Abnormal PJK was defined by a proximal junctional angle greater than 10 degrees and at least 10 degrees greater than the corresponding preoperative measurement. DJK was similarly defined between the caudal endplate of the lower instrumented vertebra to the caudal endplate that was 1 vertebra below. The incidence of PJK as defined above was seen in 20 patients (30%). The development of PJK was associated with failure to incorporate the proximal end vertebra (15 patients), disruption of junctional ligamentum flavum (3 patients), or combination of both (2 patients). The most common cause of inappropriate end vertebra selection was poor visualization of the upper thoracic vertebra.DJK occurred in 8 patients (12%) and 7 of them had fusion short of including the first lordotic disc. The incidence of PJK can be minimized by the appropriate selection of the upper end vertebra to be fused and avoiding disruption of the junctional ligamentum flavum. The development of DJK can be minimized by incorporation of the first lordotic disc into the fusion construct.
A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis ... more A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis with fusion from T10 or higher to S1. To document the perioperative and long-term complications and instrumentation problems, and to attempt to determine variables which may influence these problems. It is not a study of curve correction, balance, or functional outcome. Several previous studies from this and other centers have shown a relatively high complication rate for this select group of patients. Various fusion techniques (anterior, posterior, autograft, allograft), various instrumentation techniques, and various immobilization techniques have created confusion as to the best methodology to employ. Minimal 2-year follow-ups have been standard, but longer follow-ups have shown additional problems. The study cohort consisted of 50 adult patients from a single center who had undergone corrective scoliosis surgery from T10 or higher to the sacrum and who had at least a 5-year minimum follow-up. The mean age was 54 years (range, 18-72), and the mean follow-up was 9.7 years (range, 5-26). All radiographs, office charts, and hospital charts were combed by an independent investigator for complications, which were divided into major and minor, as well as early, intermediate and late. The curvature values and corrections were the subject of a different article, and were not included in this study. There were no deaths or spinal cord injuries. Six patients had nerve root complications, 4 of which totally recovered. Pseudarthrosis was seen in 24% of the patients, only 25% of which were detected within the 2-year follow-up period. Pseudarthrosis was most common at the lumbosacral level. There was no statistical difference in the pseudarthrosis rate between patients with sacral-only fixation versus iliac fixation. Painful implants requiring removal were noted in 11 of the 50 patients. Long fusions to the sacrum in adults with scoliosis continue to have a high complication rate. As compared to the original publications in the 1980s (Kostuik and Hall, Spine 1983;8:489-500; Balderston et al, Spine 1986;11:824-9) the more recent articles have shown a reduction, but not elimination of the pseudarthrosis problem using segmental instrumentation and anterior fusion of the lumbar spine coupled with structural interbody grafting at L4-L5 and L5-S1. Two-year follow-up is inadequate as pseudarthrosis and painful implants often are detected later. Only 3 of the 12 patients with pseudarthrosis were detected within the first 2 years after surgery.
Retrospective study of patients after extension of previous scoliosis fusions to the pelvis. To d... more Retrospective study of patients after extension of previous scoliosis fusions to the pelvis. To determine whether modern instrumentation and surgical techniques provide for increased fusion rates with fewer complications. Traditionally, long fusions to the pelvis in adults with idiopathic scoliosis have resulted in high complication rates, including pseudarthrosis. The hospital and clinic charts of 41 patients (40 female, 1 male) were reviewed 41 months (range: 24-116) after surgery for extension to the pelvis of previous scoliosis fusions. Thirty-nine of 41 had a combined anteroposterior fusion extension; two had posterior extension only. In 37 of 41 patients, Cotrel-Dubousset (CD) instrumentation was used; in two, Isola (Acromed Corp., Cleveland, OH), in one, TSRH; (Sofamor-Danek, Memphis, TN), and in one, Synergy (Cross Medical Products, Columbus, OH). Parameters analyzed were fusion rate, sagittal and coronal balance, lumbar lordosis, length of fusion extension, and distal fixation method. Complications were seen in 30 of 41 patients. The pseudarthrosis rate was 37% (15/41) and was significantly related to the method of distal posterior fixation. With sacral fixation only, the rate was 53% (8/15), with iliac fixation only 42% (3/7), and with both iliac and sacral fixation 21% (4/19; P < 0.05). This was not correlated with fusion rate, and the length of fusion extension did not affect the pseudarthrosis rate or sagittal balance. When fixed to the ilium and sacrum, modern instrumentation appears capable of maintaining sagittal balance with lower rates of pseudarthrosis when previous scoliosis fusions are extended to the pelvis. The complication rate remains significant.
Objective To define the origin of radiculopathy of patients with degenerative lumbar scoliosis an... more Objective To define the origin of radiculopathy of patients with degenerative lumbar scoliosis and to assess the correlation between percentage of radiculating pain relief with selective nerve root injections and lateral canal dimensions. Methods Ninety-three consecutive ...
The purpose is to define the origin of radiculopathy of patients with degenerative lumbar scolios... more The purpose is to define the origin of radiculopathy of patients with degenerative lumbar scoliosis-stenosis and to assess the correlation between percentage of initial radicular leg pain relief with selective nerve root injections and lateral canal dimensions. Retrospective clinical study. Thirty-six consecutive patients (average age 72) from Twin Cities Spine Center with degenerative lumbar scoliosis (average major curve 25°) and radicular symptoms were studied. Patients underwent 46 selective steroid injections of nerve roots concordant with clinical symptomatology. Radiographic measurements included major and lumbosacral curve Cobb angle. Computerized measurements of magnetic resonance imaging (MRI) included minimum subarticular height and foramen cross-sectional area of the nerve roots that were injected. Initial response from the nerve root injections was also rated. Twenty-five percent of nerve root symptoms were coming from the major curve, 72.2% from the lumbosacral hemicurve and 2.8% from both (P<0.001). The affected nerve roots were more frequently the L4 (34.8%) and L5 (28.3%) nerve roots. A total of 71.7% of radicular symptoms were originating from the concavity of the curve and 28.7% from the convexity (P<0.001). The relief from injections was more than 50% in 75% of the patients at 15 days postinjection. There was no statistical significant correlation (P>0.05) between the lateral canal dimensions and the initial response to injection of anesthetic plus steroid injection. In degenerative lumbar scoliotic curves, radicular symptoms are attributed mainly to nerve roots exiting from the concavity of the lumbosacral hemicurve. No evidence was found that the rate of initial relief from selective nerve root injections correlates with the degree of stenosis noted in the MRI.
The objective of this study is to evaluate the effectiveness of a specific methodology for plain ... more The objective of this study is to evaluate the effectiveness of a specific methodology for plain radiographic assessment of lumbar pedicle screw position. To evaluate the effectiveness of using orthogonal plain radiographs and a systematic method of interpretation, developed by the senior author, in assessing the placement of lumbar and lumbosacral pedicle screws. This was an adult cadaver study of the accuracy of using plain radiographs or computed tomography to assess pedicle screw position. Plain radiographs were performed and compared with computed tomography (CT) scans. Gross anatomic dissections were performed to directly confirm screw position. Variables, including screw material, radiographic view, and screw dimensions, were assessed for their effect on the ability of physicians to determine pedicle screw position. Multiple readers were included in the study, including 1 spine Fellow, 3 experienced orthopedic spine surgeons, and 1 neuroradiologist. Five adult cadaveric spines were instrumented with titanium pedicle screws from L1 to S1. Screws were placed outside the confines of the pedicle in all 4 quadrants or within the pedicle using a Latin-Square design. Each cadaver was imaged with orthogonal radiographs and high-resolution CT scans. The spines were then reimaged after the instrumentation was replaced with stainless steel screws placed in the identical position. Finally, each spine was dissected to assess the exact position of the screws. Images were read in a blinded fashion by 1 spine fellow, 2 staff surgeons, and a staff radiologist. The results were compared with the known screw positions at dissection. In total, 120 pedicle screws were placed, 44 (38%) outside the confines of the pedicle. Sensitivity, defined as the percent of the misplaced screws that were correctly identified, was similar across the 3 diagnostic tests, but markedly improved when all CT formats were considered together. Similarly, specificity, defined as the percent of screws correctly read as being placed within the pedicle, was independent of radiographic examination. Sensitivity of the radiographic technique was 70.1% and specificity was 83.0%, whereas sensitivity for CT scans was 84.7% and specificity was 89.7%. There was an observed association with anatomic level, with a consistently less accuracy in detecting screw position at L1 with plain x-ray (P=0.001). Additionally, correct position of stainless steel screws was more difficult to detect as compared with titanium (P=0.033) using either x-rays or CT. Other variables examined, such as screw length and screw diameter, did not have an effect on the ability to read the positioning. CT scans, often considered the "gold standard" for clinical assessment of pedicle screw placement, have limitations when validated with gross anatomical dissection. The described systematic method for evaluating pedicle screw placement using orthogonal plain radiographs attained accuracy comparable to high-resolution CT scans.
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Papers by Francis Denis