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 Journal of bone and joint surgery. American volume, 1987
From 1960 through 1978, a total of 274 patients who had a diagnosis of Scheuermann kyphosis were ... more From 1960 through 1978, a total of 274 patients who had a diagnosis of Scheuermann kyphosis were treated with a Milwaukee brace at the Twin Cities Scoliosis Center. We analyzed the long-term results in 120 patients who had used the Milwaukee brace and had been followed for at least five years after the completion of treatment. The average age of the patients at the initiation of treatment was twelve years and five months, the average age at the completion of treatment was sixteen years and one month, and the average age at the last follow-up examination was twenty-four years. Of the patients who wore the brace consistently, seventy-six showed improvement in the kyphosis between the initial evaluation and the evaluation at final follow-up, while twenty-four showed worsening and ten were unchanged. Seven of the twenty-four patients who were worse had had surgery before the review for this study. The indication for surgery was a kyphosis of more than 60 degrees that was increasing and ...
Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion wi... more Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion with Luque-Galveston instrumentation between 1982 and 1986. The minimum follow-up was 4 years. Diagnoses included cerebral palsy in 34 patients and other neuromuscular diseases in another 34 patients. The average age was 14 years. Twenty patients also had anterior spine fusion without instrumentation. Preoperatively the average scoliosis was 73 degrees and this was corrected to 33 degrees at final follow-up. The subgroup having anterior discectomy and fusion had a more severe scoliosis and pelvic obliquity, but the percent of correction was similar to that of the group with posterior reconstruction only. Twenty-four patients who had an associated significant sagittal plane deformity were corrected to a physiologic curvature. A postoperative thoracolumbosacral orthosis was used in 27 patients, and a molded seating orthosis was used in 18. Although the rate of complications was high (62%), most of them were minor. Instrumentation problems occurred in 14 patients (21%), only 4 of them having broken rods. There were no broken wires. Pseudarthrosis occurred in seven patients (10%). Three patients had minor neurologic deficits, all transient. The "windshield-wiper" sign was defined as any radiolucency of 2 mm or greater. Twenty-six patients had this sign at follow-up, and this group had a higher percentage of complications, but the existence of this sign did not necessarily indicate a problem.
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.
Safe radiography in scoliosis management is based on a sound knowledge of 1) the radiographic ima... more Safe radiography in scoliosis management is based on a sound knowledge of 1) the radiographic imaging process, 2) the degree of risk to the patient from radiation exposure, and 3) the radiographic requirements to both evaluate and follow patients with spine deformity. This paper is a current review of the subject and work done at the authors' centers. It includes recommendations for reducing the radiation risk while maintaining necessary diagnostic information.
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.
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.
A study documenting major complications encountered in revision procedures for lumbar cage pseudo... more A study documenting major complications encountered in revision procedures for lumbar cage pseudoarthrosis. To document the perioperative complications associated with revision surgery for threaded cylindrical cage pseudoarthrosis. Pseudoarthrosis after cylindrical cage placement manifests as persistent or recurrent pain and disability after surgery. Revision strategies include isolated posterior stabilization and posterior bone grafting, versus circumferential revision where an attempt is made to remove the cages anteriorly, followed by posterior stabilization and fusion. Potential complications associated with these revision procedures have not been adequately documented in the past. Forty-seven consecutive patients with the diagnosis of cylindrical cage pseudoarthrosis were surgically treated with either a circumferential revision (AP) or an isolated posterior instrumented fusion (P). All intraoperative and postoperative complications were documented. Radiographic interbody fusion rates and preoperative and postoperative visual analog scale (VAS) scores were documented. Three of the AP patients, all with anterior cage placement at L5-S1, had iliac vein lacerations requiring repair. A fourth patient had a ureteral injury requiring subsequent nephrectomy. Three patients who underwent circumferential revision and 2 patients who had an isolated posterior procedure had postoperative complications, including 2 infections (1 AP and 1 P), 1 radiculopathy (P), and 2 patients with prolonged ileus (both AP). There was a statistically significant decrease in overall VAS scores postoperatively for the 2 groups using the paired t test (P<0.0001). There was no difference in either the preoperative (P=0.22) or 2-year postoperative (P=0.30) VAS scores between the AP and P groups [rank-sum (Mann-Whitney) t tests]. Interbody fusion was achieved in 79% (30 of 38 levels) in the AP group. The interbody fusion rate was 37% (8 of 22) for the P group. Circumferential revision including cage removal, structural allograft placement, and posterior stabilization is associated with increased perioperative complications. Although an anterior approach showed increased interbody fusion rates, this technique did not lead to more superior clinical outcomes based on VAS scores. It remains to be shown by larger prospective studies if there is a true difference in outcome between these 2 groups that will justify the increased perioperative morbidity associated with attempted cage removal.
A retrospective review of 25 patients with scoliosis secondary to syringomyelia was conducted. Al... more A retrospective review of 25 patients with scoliosis secondary to syringomyelia was conducted. All patients had large syrinxes, but only 10 patients had abnormal neurologic findings, suggesting that subtle neurologic findings in patients with scoliosis should not be underestimated and supporting liberal use of magnetic resonance imaging (MRI). The results of three approaches to the care of these patients were reviewed: passive observation, bracing, and spinal fusion. Curves progressed > or = 5 degrees in patients aged < 10 years who were observed, but in children aged > 10 years, curves progressed > or = 10 degrees. Curves responded well to bracing, but correction was not maintained out of brace for patients with progressive and/or severe curves. Good corrective was achieved safely during operation.
Reconstructive spine surgery in pediatric patients with major loss in vital capacity. BA RAWLINS,... more Reconstructive spine surgery in pediatric patients with major loss in vital capacity. BA RAWLINS, RB WINTER, JE LONSTEIN, F DENIS ...
School screening for scoliosis is a well accepted technique for the early detection of spinal def... more School screening for scoliosis is a well accepted technique for the early detection of spinal deformities. We reviewed the experience in Minnesota over the past eight years, with an average of one-quarter of a million children being screened yearly. Of the children screened, 3.4 per cent were referred for evaluation and scoliosis was found in 1.2 per cent. The number of children requiring operations for adolescent idiopathic scoliosis has diminished since 1970. The average curve for which a surgical procedure was done has also diminished from 60 to 42 degrees. The cost of the program is low, averaging 6.6 cents per student screened. This compares with a so-called time cost averaging thirty-five cents. Voluntary scoliosis screening in Minnesota is an efficient and cost-effective program.
This study retrospectively reviewed spine surgical procedures complicated by wound infection and ... more This study retrospectively reviewed spine surgical procedures complicated by wound infection and managed by a protocol including the use of vacuum-assisted wound closure (VAC). To define factors influencing the number of debridements needed before the final wound closure by applying VAC for patients with postoperative spinal wound infections. VAC has been suggested as a safe and probably effective method for the treatment of spinal wound infections. The risk factors for infection resistance and need for debridement revisions after VAC placement are unknown. Seventy-three consecutive patients with 79 wound infections after undergoing spine surgery were studied (6 of them had recurrence of infection). All patients were taken to the operating room for irrigation and debridement under general anesthesia followed by placement of the VAC with subsequent delayed closure of the wound. Linear regression and t test were used to identify if the following variables were risk factors for the resistance of infection to VAC treatment: timing of clinical appearance of infection, depth of infection (deep or superficial), presence of instrumentation, positive culture for methicillin-resistant Staphylococcus aureus (MRSA) or more than 1 microorganism, age of the patient, and presence of other comorbidities. There were 34 males and 39 females with an average age of 58.4 years (21 to 82). Once the VAC was initiated, there was an average of 1.4 procedures until and including closure of the wound. The wound was closed an average of 7 days (range 5 to 14) after the placement of the initial VAC on the wound. The average follow-up was 14 months (range 12 to 28). All of the patients but 2 achieved a clean, closed wound without removal of instrumentation at a minimum follow-up of 1 year. Sixty patients had implants (instrumentation or allograft) within the site of wound infection. Thirteen patients had a decompression with exposed dura. Sixty-four infections (81%) presented with a draining wound within the first 6 weeks postoperatively. Sixty-nine infections (87.3%) were deep below the fascia. There was no statistical significance (P>0.05) of all tested risk factors for the resistance of infection to treatment with the VAC system. The parameter more related to repeat VAC procedures was the culture of MRSA or multiple bacteria. VAC therapy may be an effective adjunct in closing spinal wounds even after the repeat procedures. The MRSA or multibacterial infections seem to be most likely to need repeat debridements and VAC treatment before final wound closure.
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 Journal of bone and joint surgery. American volume, 1987
From 1960 through 1978, a total of 274 patients who had a diagnosis of Scheuermann kyphosis were ... more From 1960 through 1978, a total of 274 patients who had a diagnosis of Scheuermann kyphosis were treated with a Milwaukee brace at the Twin Cities Scoliosis Center. We analyzed the long-term results in 120 patients who had used the Milwaukee brace and had been followed for at least five years after the completion of treatment. The average age of the patients at the initiation of treatment was twelve years and five months, the average age at the completion of treatment was sixteen years and one month, and the average age at the last follow-up examination was twenty-four years. Of the patients who wore the brace consistently, seventy-six showed improvement in the kyphosis between the initial evaluation and the evaluation at final follow-up, while twenty-four showed worsening and ten were unchanged. Seven of the twenty-four patients who were worse had had surgery before the review for this study. The indication for surgery was a kyphosis of more than 60 degrees that was increasing and ...
Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion wi... more Sixty-eight patients with neuromuscular spine deformity were treated by posterior spine fusion with Luque-Galveston instrumentation between 1982 and 1986. The minimum follow-up was 4 years. Diagnoses included cerebral palsy in 34 patients and other neuromuscular diseases in another 34 patients. The average age was 14 years. Twenty patients also had anterior spine fusion without instrumentation. Preoperatively the average scoliosis was 73 degrees and this was corrected to 33 degrees at final follow-up. The subgroup having anterior discectomy and fusion had a more severe scoliosis and pelvic obliquity, but the percent of correction was similar to that of the group with posterior reconstruction only. Twenty-four patients who had an associated significant sagittal plane deformity were corrected to a physiologic curvature. A postoperative thoracolumbosacral orthosis was used in 27 patients, and a molded seating orthosis was used in 18. Although the rate of complications was high (62%), most of them were minor. Instrumentation problems occurred in 14 patients (21%), only 4 of them having broken rods. There were no broken wires. Pseudarthrosis occurred in seven patients (10%). Three patients had minor neurologic deficits, all transient. The "windshield-wiper" sign was defined as any radiolucency of 2 mm or greater. Twenty-six patients had this sign at follow-up, and this group had a higher percentage of complications, but the existence of this sign did not necessarily indicate a problem.
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.
Safe radiography in scoliosis management is based on a sound knowledge of 1) the radiographic ima... more Safe radiography in scoliosis management is based on a sound knowledge of 1) the radiographic imaging process, 2) the degree of risk to the patient from radiation exposure, and 3) the radiographic requirements to both evaluate and follow patients with spine deformity. This paper is a current review of the subject and work done at the authors' centers. It includes recommendations for reducing the radiation risk while maintaining necessary diagnostic information.
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.
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.
A study documenting major complications encountered in revision procedures for lumbar cage pseudo... more A study documenting major complications encountered in revision procedures for lumbar cage pseudoarthrosis. To document the perioperative complications associated with revision surgery for threaded cylindrical cage pseudoarthrosis. Pseudoarthrosis after cylindrical cage placement manifests as persistent or recurrent pain and disability after surgery. Revision strategies include isolated posterior stabilization and posterior bone grafting, versus circumferential revision where an attempt is made to remove the cages anteriorly, followed by posterior stabilization and fusion. Potential complications associated with these revision procedures have not been adequately documented in the past. Forty-seven consecutive patients with the diagnosis of cylindrical cage pseudoarthrosis were surgically treated with either a circumferential revision (AP) or an isolated posterior instrumented fusion (P). All intraoperative and postoperative complications were documented. Radiographic interbody fusion rates and preoperative and postoperative visual analog scale (VAS) scores were documented. Three of the AP patients, all with anterior cage placement at L5-S1, had iliac vein lacerations requiring repair. A fourth patient had a ureteral injury requiring subsequent nephrectomy. Three patients who underwent circumferential revision and 2 patients who had an isolated posterior procedure had postoperative complications, including 2 infections (1 AP and 1 P), 1 radiculopathy (P), and 2 patients with prolonged ileus (both AP). There was a statistically significant decrease in overall VAS scores postoperatively for the 2 groups using the paired t test (P<0.0001). There was no difference in either the preoperative (P=0.22) or 2-year postoperative (P=0.30) VAS scores between the AP and P groups [rank-sum (Mann-Whitney) t tests]. Interbody fusion was achieved in 79% (30 of 38 levels) in the AP group. The interbody fusion rate was 37% (8 of 22) for the P group. Circumferential revision including cage removal, structural allograft placement, and posterior stabilization is associated with increased perioperative complications. Although an anterior approach showed increased interbody fusion rates, this technique did not lead to more superior clinical outcomes based on VAS scores. It remains to be shown by larger prospective studies if there is a true difference in outcome between these 2 groups that will justify the increased perioperative morbidity associated with attempted cage removal.
A retrospective review of 25 patients with scoliosis secondary to syringomyelia was conducted. Al... more A retrospective review of 25 patients with scoliosis secondary to syringomyelia was conducted. All patients had large syrinxes, but only 10 patients had abnormal neurologic findings, suggesting that subtle neurologic findings in patients with scoliosis should not be underestimated and supporting liberal use of magnetic resonance imaging (MRI). The results of three approaches to the care of these patients were reviewed: passive observation, bracing, and spinal fusion. Curves progressed > or = 5 degrees in patients aged < 10 years who were observed, but in children aged > 10 years, curves progressed > or = 10 degrees. Curves responded well to bracing, but correction was not maintained out of brace for patients with progressive and/or severe curves. Good corrective was achieved safely during operation.
Reconstructive spine surgery in pediatric patients with major loss in vital capacity. BA RAWLINS,... more Reconstructive spine surgery in pediatric patients with major loss in vital capacity. BA RAWLINS, RB WINTER, JE LONSTEIN, F DENIS ...
School screening for scoliosis is a well accepted technique for the early detection of spinal def... more School screening for scoliosis is a well accepted technique for the early detection of spinal deformities. We reviewed the experience in Minnesota over the past eight years, with an average of one-quarter of a million children being screened yearly. Of the children screened, 3.4 per cent were referred for evaluation and scoliosis was found in 1.2 per cent. The number of children requiring operations for adolescent idiopathic scoliosis has diminished since 1970. The average curve for which a surgical procedure was done has also diminished from 60 to 42 degrees. The cost of the program is low, averaging 6.6 cents per student screened. This compares with a so-called time cost averaging thirty-five cents. Voluntary scoliosis screening in Minnesota is an efficient and cost-effective program.
This study retrospectively reviewed spine surgical procedures complicated by wound infection and ... more This study retrospectively reviewed spine surgical procedures complicated by wound infection and managed by a protocol including the use of vacuum-assisted wound closure (VAC). To define factors influencing the number of debridements needed before the final wound closure by applying VAC for patients with postoperative spinal wound infections. VAC has been suggested as a safe and probably effective method for the treatment of spinal wound infections. The risk factors for infection resistance and need for debridement revisions after VAC placement are unknown. Seventy-three consecutive patients with 79 wound infections after undergoing spine surgery were studied (6 of them had recurrence of infection). All patients were taken to the operating room for irrigation and debridement under general anesthesia followed by placement of the VAC with subsequent delayed closure of the wound. Linear regression and t test were used to identify if the following variables were risk factors for the resistance of infection to VAC treatment: timing of clinical appearance of infection, depth of infection (deep or superficial), presence of instrumentation, positive culture for methicillin-resistant Staphylococcus aureus (MRSA) or more than 1 microorganism, age of the patient, and presence of other comorbidities. There were 34 males and 39 females with an average age of 58.4 years (21 to 82). Once the VAC was initiated, there was an average of 1.4 procedures until and including closure of the wound. The wound was closed an average of 7 days (range 5 to 14) after the placement of the initial VAC on the wound. The average follow-up was 14 months (range 12 to 28). All of the patients but 2 achieved a clean, closed wound without removal of instrumentation at a minimum follow-up of 1 year. Sixty patients had implants (instrumentation or allograft) within the site of wound infection. Thirteen patients had a decompression with exposed dura. Sixty-four infections (81%) presented with a draining wound within the first 6 weeks postoperatively. Sixty-nine infections (87.3%) were deep below the fascia. There was no statistical significance (P>0.05) of all tested risk factors for the resistance of infection to treatment with the VAC system. The parameter more related to repeat VAC procedures was the culture of MRSA or multiple bacteria. VAC therapy may be an effective adjunct in closing spinal wounds even after the repeat procedures. The MRSA or multibacterial infections seem to be most likely to need repeat debridements and VAC treatment before final wound closure.
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Papers by J. Lonstein