Biomedical subjects

Steven D Glassman

Publications and source records attributed to Steven D Glassman.

At least 19 recordsLinked to original sources

PubMed2007

The selection of operative versus nonoperative treatment in patients with adult scoliosis.

STUDY DESIGN: Retrospective case-control matched series. OBJECTIVE: The purpose of this study is to define factors that influence the patient and surgeon in the selection of surgical versus nonsurgical treatment for adult scoliosis. SUMMARY OF BACKGROUND DATA: There is no literature that specifically examines why adult scoliosis patients and/or their surgeons choose surgical versus nonsurgical treatment. METHODS: This study analyzes a prospective multicentered database for adult spinal deformity. A logistic regression technique was used to perform case-control matching. A total of 161 matched pairs were compared for radiographic characteristics, questionnaire responses, and standardized outcome measures. RESULTS: Nonsurgical patients had greater preoperative medical risk factors. Surgical patients had larger thoracic (51 degrees vs. 44 degrees, P = 0.006) and thoracolumbar/lumbar curves (55 degrees vs. 43 degrees, P = 0.000). Surgical patients had more frequent leg pain (47% vs. 35%, P = 0.04). They reported a higher mean level of daily back pain (P = 0.008) and more frequent moderate-to-severe back pain over the past 6 months (P = 0.03). There were also significant differences in perception of appearance and social function between the cohorts. CONCLUSIONS: This study emphasizes the complexity of surgical decision making for adult scoliosis patients. It also underscores the importance of patient-based health status measures in evaluating the adult scoliosis patient.

Adolescent↗

PubMed2006

Reliability and agreement between fine-cut CT scans and plain radiography in the evaluation of posterolateral fusions.

BACKGROUND CONTEXT: Current imaging techniques used to evaluate fusion status after a posterolateral fusion such as radiographs, computed axial tomography (CT) scans, and tomograms are known to be inaccurate, with error rates estimated from 20% to 40%. Previous studies evaluated CT scans using 2-4-mm thick slices with limited reconstructions. PURPOSE: The purpose of this study is to determine the intraobserver and interobserver agreement of plain radiographs and fine-cut (1-mm) CT scans with sagittal and coronal reconstructions in evaluating fusion status after instrumented posterolateral fusions. The correlation between radiographic evaluations and CT scan evaluations was also analyzed. STUDY DESIGN/SETTING: Cross-sectional, blinded. PATIENT SAMPLE: One-year radiographs and CT scans of 86 patients who had single-level instrumented posterolateral fusions. OUTCOME MEASURES: Fusion grades based on previously published criteria were determined. METHODS: Three spine surgeons graded the fusions of 86 patients who had single-level instrumented posterolateral fusions using 1-year postoperative flexion/extension lateral and anteroposterior radiographs, and fine-cut CT scans with sagittal and coronal reconstructions. The technique used to obtain the radiographs and the CT scans was the same in all cases. Two separate readings, 2 weeks apart, were done on each patient by each surgeon. The kappa coefficients for interobserver and intraobserver variability were determined. RESULTS: The intraobserver agreement using CT scans to assess fusion status was moderate for both classification systems (Molinari=0.48, Glassman 0.47). The intraobserver agreement using X-rays to assess fusion status was fair for the Molinari classification (kappa=0.37) and moderate for the Glassman classification (kappa=0.43). The interobserver agreement using CT scans to assess fusion status was moderate for both classification systems (Molinari=0.48, Glassman 0.48). The interobserver agreement using X-rays to assess fusion status was fair for both classification systems (Molinari=0.24, Glassman 0.26). Observers agreed most often when the fusion was assessed as solid (Molinari k=0.61, Glassman k=0.63). The rating on the radiographs and CT scans agreed only 46% to 59% of the time. CONCLUSIONS: Fine-cut CT scans with reconstructions have a considerably greater degree of interobserver and intraobserver agreement compared with flexion/extension and anteroposterior radiographs. Observers agree most often when the fusion is assessed as solid. Fusion evaluation based on radiographs agrees with CT scans only half the time. Future studies are needed to correlate the findings on fine-cut CT scans with surgical exploration.

Cross-Sectional Studies↗

PubMed2006

Posterolateral lumbar spine fusion with INFUSE bone graft.

BACKGROUND CONTEXT: INFUSE has been proven effective in conjunction with threaded cages and bone dowels for single-level anterior lumbar interbody fusion (ALIF). The published experience with posterolateral fusion, although encouraging, utilizes a significantly higher dose and concentration of recombinant human bone morphogenic protein-2 (rhBMP-2) and a different carrier than the commercially available INFUSE. PURPOSE: To present an assessment of fusion rate for posterolateral spine fusion with INFUSE Bone Graft. STUDY DESIGN/SETTING: Retrospective review of patients treated using INFUSE in posterolateral spine fusion in a single institution. PATIENT SAMPLE: 91 patients with minimum 2-year follow-up who underwent posterolateral spine fusion using INFUSE as an iliac crest bone graft (ICBG) substitute. OUTCOME MEASURES: Fusion rate based on fine-cut computed tomographic (CT) scans with sagittal and coronal reconstructions. METHODS: Fusion was performed using one large INFUSE kit (12 mg rhBMP-2, 1.5 mg/mL), which was prepared according to the manufacturer's instructions. The INFUSE sponge was wrapped around the local bone or graft extender and placed over the decorticated surfaces in the lateral gutters. Postoperative CT scans with reconstructions were reviewed by two independent orthopedic spine surgeons. CT scans of a comparison group of 35 patients who underwent primary single-level posterolateral fusion with ICBG were also reviewed. RESULTS: The overall group had a mean 4.38 CT fusion grade and a 6.6% nonunion rate. Primary one-level fusion cases (n=48) had a mean 4.42 fusion grade a 4.2% nonunion rate. Primary multilevel fusions (n=27) had a mean 4.65 CT grade and no nonunions detected. Assessment of the 35 primary one-level ICBG control cases demonstrated a mean CT grade of 4.35 and a nonunion rate of 11.4%. In the 16 cases of revision for prior nonunion, mean CT grade was 3.81 and 4 subjects had nonunions. Additional subgroup analysis showed that smokers (n=14) had a mean 4.32 CT grade with no nonunions. Men had a mean 4.04 CT grade and an 11.1% nonunion rate compared with a mean 4.61 CT grade and 3.6% nonunion rate in women. This difference was statistically significant (p=.036). No significant differences in fusion rate were observed based upon the specific graft extender used (p=.200). CONCLUSIONS: Posterolateral spine fusion involves a more difficult healing environment with a limited surface for healing, a gap between transverse processes and the milieu of distractive forces. Historically, only ICBG has been able to overcome these challenges and reliably generate a successful posterolateral lumbar spine fusion. In contrast to prior studies, clinically available INFUSE delivers only 12 mg rhBMP-2 at a concentration of 1.5 mg/mL. Despite the lower dose and concentration of rhBMP-2, this study suggests that fusion success with INFUSE is equivalent to ICBG for posterolateral spine fusion. As with ICBG, development of solid fusion or nonunion is a multifactorial process. The use of INFUSE is not a substitute for proper surgical technique or optimization of patient-related risk factors. Additional studies are needed to determine the incremental benefit of a greater rhBMP-2 dose or use of alternative carriers for posterolateral fusion. Finally, correlation between radiographic findings and clinical outcomes, and a cost-benefit analysis are needed. Despite these issues, this study presents compelling evidence that commercially available INFUSE is an effective ICBG substitute for one- and two-level posterolateral instrumented spine fusion.

Adult↗

PubMed2006

Clinical outcomes and fusion success at 2 years of single-level instrumented posterolateral fusions with recombinant human bone morphogenetic protein-2/compression resistant matrix versus iliac crest bone graft.

STUDY DESIGN: This is a prospective, randomized study comparing iliac crest bone graft to bone morphogenetic protein (BMP)/compression resistant matrix in instrumented posterolateral fusions for single-level lumbar degenerative disease. A higher recombinant human bone morphogenetic protein (rhBMP)-2 dose and a carrier specific for posterior spine applications were used. OBJECTIVES: As part of a Food and Drug Administration IDE study, clinical outcomes and fusion rates of single-level instrumented posterolateral fusions using iliac crest bone graft or BMP/compression resistant matrix were evaluated. SUMMARY OF BACKGROUND DATA: Although iliac crest graft is the gold standard for lumbar fusion, alternatives to obviate the morbidity of graft harvest have become available. Randomized clinical trials have demonstrated equivalent fusion rates and clinical outcomes with rhBMP-2 and a collagen sponge versus autograft in anterior lumbar fusions. A human pilot study using rhBMP-2 with biphasic calcium phosphate demonstrated similar results for posterolateral fusions. METHODS: Demographic and perioperative data, Short Form 36, Oswestry Low Back Pain Disability Index, and leg and back pain scores were determined before surgery, and 1.5, 3, 6, 12, and 24 months after surgery. Independent neuroradiologists' evaluation of fine-cut computerized tomography scans with reconstructions were obtained at 6, 12, and 24 months. RESULTS: There were 98 subjects, 45 in the iliac crest bone graft group and 53 in the BMP/compression resistant matrix group. There were no significant differences for age, weight, sex, smoking, or previous surgery between the groups. The average operative time (2.9 hours) and blood loss (465 cc) in the iliac crest bone graft group was greater than in the BMP/compression resistant matrix group (2.4 hours and 273 cc). There were no significant differences in any outcome measure at all time intervals. The fusion rate was lower in the iliac crest bone graft group (73%) than in the BMP/compression resistant matrix group (88%) at P = 0.051. CONCLUSION: There was significant improvement of Short Form 36 (physical component score and pain), Oswestry Low Back Pain Disability Index, and leg and back pain scores in both groups over all time intervals. Surgical time and blood loss were significantly less in the BMP/compression resistant matrix group. The fusion rate in the BMP/compression resistant matrix group was significantly higher than the iliac crest bone graft group.

Bone Morphogenetic Protein 2↗

PubMed2006

Nonsurgical resource utilization in adult spinal deformity.

STUDY DESIGN: The enrollment data were retrospectively reviewed for 1,061 patients entered into a prospective multicenter study of adult spinal deformity between January 2002 and June 2004. OBJECTIVE: The purpose of this study is to quantify and analyze the use of nonsurgical resources in patients with adult spinal deformity. SUMMARY OF BACKGROUND DATA: Limited data exist regarding the utilization of nonsurgical treatment methods for adult spinal deformity. METHODS: Demographic data, surgical history, symptom assessment, and nonsurgical treatment regimen were reviewed. Health status measures were the SF-12, SRS-29, and ODI. Nonsurgical patients were divided into low- and high-symptom subgroups based on age adjusted ODI score. Resource utilization was analyzed based on both patient and physician questionnaire responses. RESULTS: High- and low-symptom nonsurgical subgroups differed significantly on all reported health status measures (P < 0.0001). High-symptom patients used greater resources in terms of narcotics, epidural blocks, and physical agent methods (P < 0.001), analgesics (P < 0.01), pain management referral and bed rest (P < 0.02), strength training, nerve root blocks, and stabilization exercises (P < 0.05). CONCLUSIONS: The results of this study demonstrate that, within the population of adult deformity patients, distinct high- and low-symptom groups exist and can be clearly identified. While high-symptom patients used significantly greater resources, most low-symptom patients used nonsurgical resources as well.

Adult↗

PubMed2006

Adverse effects associated with high-dose recombinant human bone morphogenetic protein-2 use in anterior cervical spine fusion.

STUDY DESIGN: A retrospective review of patients who underwent an anterior cervical fusion using recombinant human bone morphogenetic protein (rhBMP)-2 with an absorbable collagen sponge (INFUSE; Medtronic Sofamor Danek, Minneapolis, MN). OBJECTIVE: To ascertain the complication rate after the use of high-dose INFUSE in anterior cervical fusions. SUMMARY OF BACKGROUND DATA: The rhBMP-2 has been primarily investigated in lumbar spine fusions, where it has significantly enhanced the fusion rate and decreased the length of surgery, blood loss, and hospital stay. METHODS: We present 151 patients who underwent either an anterior cervical discectomy and fusion (n = 138) or anterior cervical vertebrectomy and fusion (n = 13) augmented with high-dose INFUSE between July 2003 and March 2004. The rhBMP-2 (up to 2.1 mg/level) was used in the anterior cervical discectomy and fusions. RESULTS: A total of 35 (23.2%) patients had complications after the use of high-dose INFUSE in the cervical spine. There were 15 patients diagnosed with a hematoma, including 11 on postoperative day 4 or 5, of whom 8 were surgically evacuated. Thirteen individuals had either a prolonged hospital stay (> 48 hours) or hospital readmission because of swallowing/breathing difficulties or dramatic swelling without hematoma. CONCLUSIONS: A significant rate of complications resulted after the use of a high dose of INFUSE in anterior cervical fusions. We hypothesize that in the cervical area, the putative inflammatory effect that contributes to the effectiveness of INFUSE in inducing fusion may spread to adjacent critical structures and lead to increased postoperative morbidity. A thorough investigation is warranted to determine the optimal dose of rhBMP-2 that will promote cervical fusion and minimize complications.

Adult↗

PubMed2006

Treatment of anterior cervical pseudoarthrosis: posterior fusion versus anterior revision.

BACKGROUND CONTEXT: Posterior fusion has been advocated as the most effective treatment of anterior cervical pseudoarthrosis. Authors cite the benefits of increased stability and avoiding the risk of dissection through anterior scar tissue. Despite these advantages, posterior fusion is a more extensive procedure from the standpoint of perioperative and postoperative recovery. PURPOSE: The objective of this study is to compare the results of posterior fusions to revision anterior fusions for repair of anterior cervical pseudoarthrosis. STUDY DESIGN/SETTING: This is a retrospective case series from a single institution. PATIENT SAMPLE: 120 patients with nonunion documented on flexion-extension radiographs, computed tomography (CT) scan or tomograms after an anterior cervical discectomy and fusion with at least 2-year follow-up. OUTCOME MEASURES: Surgical data, status of fusion, complications, and any revision surgeries. METHODS: Hospital and office records were reviewed to determine demographic data, surgical data, status of fusion, and any revision surgeries. Nonunion was confirmed during surgery. RESULTS: Of the 120 patients included in the study, 27 had repeat anterior procedures and 93 had posterior procedures. The proportion of smokers, the number of surgical levels, and the average time to revision in each group were similar. The average operative time for the anterior revision surgery was 134.9 minutes (range 49 to 232 minutes) with an estimated blood loss of 102.7 cc. In the posterior revision surgery the average operative time was 138.9 minutes (range 35 to 356 minutes) and an average estimated blood loss of 282.1 cc. The patients in the anterior revision group had an average hospital stay of 2.3 days (1 to 5 days), whereas those in the posterior revision group had an average hospital stay of 4.4 days (3 to 8 days). There was a 4% complication rate in the anterior revision group and an 8% complication rate in the posterior revision group. Twelve of 27 patients (44%) in the anterior revision group, and 2 of 93 patients in the posterior revision group required a second revision surgery for persistent nonunion. CONCLUSIONS: Based on these results, posterior fusion is more effective in treating anterior cervical pseudoarthrosis than revision anterior fusion. The higher fusion rate and lower incidence of repeat revision surgery offset the increased blood loss and longer recovery time associated with posterior cervical fusions.

Cervical Vertebrae↗

PubMed2006

Objective assessment of cervical spinal cord injury levels by transcranial magnetic motor-evoked potentials.

BACKGROUND: The neurologic examination serves as the optimal method to record the level of spinal cord injury (SCI). However, this test is subject to interexaminer variability. To address this shortcoming, we describe a technique that uses transcranial magnetic motor-evoked potentials (tcMMEPs) and dermatomal somatosensory-evoked potentials (d-SSEPs) to more accurately measure the precise level of SCI. METHODS: Two groups of subjects were studied: (1) complete cervical SCI (n = 10) and (2) neurologically intact volunteers (n = 10). Two additional patients were evaluated: one with a cervical central spinal cord syndrome and another with a head injury with a suspected cervical SCI. Each subject underwent upper extremity tcMMEPs and d-SSEPs. RESULTS: Transcranial magnetic motor-evoked potentials were elicited from all upper limb myotomes (C4-T1, bilaterally) in neurologically intact volunteers (20 sides). The level of injury was determined using tcMMEPs by observing the lowest level of measurable response. The level of injury obtained using tcMMEPs was the same as that determined by neurologic examination in 13 (65%) of the 20 sides. In 7 sides, tcMMEP responses were obtained 1 level lower than that assessed by physical examination. Dermatomal somatosensory-evoked potentials were obtained from all dermatomes of volunteers tested in the laboratory compared with only 5 of the 9 patients with SCI who underwent d-SSEP testing. CONCLUSION: Testing using tcMMEPs provides an objective supplement to the neurologic examination after acute cervical SCI. Dermatomal somatosensory-evoked potentials were of limited value in determining the level of cervical SCI.

Adolescent↗

PubMed2006

Lumbar degenerative classification study.

The purpose of this study was to develop and validate a classification of indications for fusion in lumbar degenerative disease. Nineteen spine surgeons reviewed a series of 32 case histories and selected the indication for fusion based on an outlined classification system. To determine the degree of interrater variability, K coefficients were calculated (K for all 32 cases, 0.63). Results from this study show the significant difficulty in classifying the indication for fusion in lumbar degenerative disease. The level of the 19 surgeons' agreement regarding surgical indication was only moderate, despite a study design that eliminated controversial issues of patient and procedure selection. To a significant extent, the difficulty in classifying indication for fusion underlines the importance of the process. If we cannot agree on why a specific patient is selected for fusion, it is then impossible to accurately compare outcomes for a given disease process or surgical technique. For this reason, an ongoing effort to refine nomenclature and classification is necessary.

Adult↗

PubMed2005

The impact of positive sagittal balance in adult spinal deformity.

STUDY DESIGN: This study is a retrospective review of 752 patients with adult spinal deformity enrolled in a multicenter prospective database in 2002 and 2003. Patients with positive sagittal balance (N = 352) were further evaluated regarding radiographic parameters and health status measures, including the Scoliosis Research Society patient questionnaire, MOS short form-12, and Oswestry Disability Index. OBJECTIVES: To examine patients with adult deformity with positive sagittal balance to define parameters within that group that might differentially predict clinical impact. SUMMARY OF BACKGROUND DATA: In a multicenter study of 298 adults with spinal deformity, positive sagittal balance was identified as the radiographic parameter most highly correlated with adverse health status outcomes. METHODS: Radiographic evaluation was performed according to a standardized protocol for 36-inch standing radiographs. Magnitude of positive sagittal balance and regional sagittal Cobb angle measures were recorded. Statistical correlation between radiographic parameters and health status measures were performed. Potentially confounding variables were assessed. RESULTS: Positive sagittal balance was identified in 352 patients. The C7 plumb line deviation ranged from 1 to 271 mm. All measures of health status showed significantly poorer scores as C7 plumb line deviation increased. Patients with relative kyphosis in the lumbar region had significantly more disability than patients with normal or lordotic lumbar sagittal Cobb measures. CONCLUSIONS: This study shows that although even mildly positive sagittal balance is somewhat detrimental, severity of symptoms increases in a linear fashion with progressive sagittal imbalance. The results also show that kyphosis is more favorable in the upper thoracic region but very poorly tolerated in the lumbar spine.

Cohort Studies↗

PubMed2005

Initial fusion rates with recombinant human bone morphogenetic protein-2/compression resistant matrix and a hydroxyapatite and tricalcium phosphate/collagen carrier in posterolateral spinal fusion.

STUDY DESIGN: Prospective, randomized, unblinded study of iliac crest bone graft (ICBG) versus recombinant human bone morphogenetic protein-2/compression resistant matrix (rhBMP-2/CRM)in a posterolateral instrumented fusion procedure. OBJECTIVES: Document initial radiographic characteristics, based on computed tomography, with rhBMP-2/CRM for posterolateral fusion at 6 and 12-month intervals. SUMMARY OF BACKGROUND DATA: As the acceptance of INFUSE bone graft as an ICBG replacement becomes more widespread, surgeons have begun to study applications for rhBMP-2 in posterior spinal fusion. Preclinical studies have examined variables including carrier composition, rhBMP-2 concentration, and rhBMP-2 dose. Pilot studies have been performed with encouraging initial results. METHODS: Patients with single level lumbar degenerative disease were enrolled in a randomized study of ICBG versus rhBMP-2/CRM in a posterolateral instrumented fusion procedure. Computed tomography scans at 6 and 12 months were graded as demonstrating no fusion (grade 1), partial or limited unilateral fusion (grade 2), partial or limited bilateral fusion (grade 3), solid unilateral fusion (grade 4), or solid bilateral fusion (grade 5). RESULTS: At our institution, 74 patients (38 rhBMP-2/CRM, 36 ICBG) reached minimum 1-year follow-up and were included in this analysis. Mean fusion grade (scale1-5) at 6 months after surgery was 4.35 in the rhBMP-2/CRM group versus 3.09 in the ICBG group (P < 0.0001). At 1 year after surgery mean fusion grade was 4.62 in the rhBMP-2/CRM group versus 3.77 in the ICBG group (P < 0.0023). CONCLUSIONS: These early results are encouraging and suggest a more rapid incorporation and development of the fusion mass with rhBMP-2/CRM than iliac crest autograft in a single level posterior instrumented fusion.

Adult↗

PubMed2005

Platelet gel (AGF) fails to increase fusion rates in instrumented posterolateral fusions.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine the effect on fusion of adding platelet gel to autologous iliac crest graft. SUMMARY OF BACKGROUND DATA: Platelet gel is an osteoinductive material prepared by ultra-concentration of platelets and contains multiple growth factors. Proprietary commercial methods are available for harvesting autologous platelet gel concentrates for use as graft supplement in spine fusions. METHODS: We reviewed 76 consecutive patients who underwent instrumented posterolateral lumbar fusion with autologous iliac crest bone graft mixed with autologous growth factor (AGF). A control group was randomly selected from patients who underwent instrumented posterolateral lumbar fusion with autologous bone graft alone. The groups were matched for age, sex, smoking history, and number of levels fused. Demographic, surgical, and clinical data were collected from medical records. Diagnosis of nonunion was based on exploration during revision surgery or evidence of nonunion on computerized tomography. The Fisher exact test was used to compare fusion rates. RESULTS: In both groups, mean age was 50 years, and 24% were smokers. The nonunion rate was 25% in the AGF group and 17% in the control group. This difference was not statistically significant (P = 0.18). CONCLUSIONS: Platelet gel preparation requires blood draws from the patient. This procedure adds to the risk and cost of surgery. The technique for AGF harvest evaluated in this study provides the highest concentration of platelets among the commercially available methods. Despite this, we showed that platelet gel failed to enhance fusion rate when added to autograft in patients undergoing instrumented posterolateral spinal fusion. The authors do not recommend the use of platelet gel to supplement autologous bone graft during instrumented posterolateral spinal fusion.

Adult↗

PubMed2005

Correlation of radiographic parameters and clinical symptoms in adult scoliosis.

STUDY DESIGN: This study is a retrospective review of the initial enrollment data from a prospective multicentered study of adult spinal deformity. OBJECTIVES: The purpose of this study is to correlate radiographic measures of deformity with patient-based outcome measures in adult scoliosis. SUMMARY OF BACKGROUND DATA: Prior studies of adult scoliosis have attempted to correlate radiographic appearance and clinical symptoms, but it has proven difficult to predict health status based on radiographic measures of deformity alone. The ability to correlate radiographic measures of deformity with symptoms would be useful for decision-making and surgical planning. METHODS: The study correlates radiographic measures of deformity with scores on the Short Form-12, Scoliosis Research Society-29, and Oswestry profiles. Radiographic evaluation was performed according to an established positioning protocol for anteroposterior and lateral 36-inch standing radiographs. Radiographic parameters studied were curve type, curve location, curve magnitude, coronal balance, sagittal balance, apical rotation, and rotatory subluxation. RESULTS: The 298 patients studied include 172 with no prior surgery and 126 who had undergone prior spine fusion. Positive sagittal balance was the most reliable predictor of clinical symptoms in both patient groups. Thoracolumbar and lumbar curves generated less favorable scores than thoracic curves in both patient groups. Significant coronal imbalance of greater than 4 cm was associated with deterioration in pain and function scores for unoperated patients but not in patients with previous surgery. CONCLUSIONS: This study suggests that restoration of a more normal sagittal balance is the critical goal for any reconstructive spine surgery. The study suggests that magnitude of coronal deformity and extent of coronal correction are less critical parameters.

Adolescent↗

PubMed2005

Is there an optimal patient stance for obtaining a lateral 36" radiograph? A critical comparison of three techniques.

STUDY DESIGN: Scoliosis patients were prospectively x-rayed in three positions with independent analysis. OBJECTIVES: To determine if one positioning technique provides superior visualization of critical landmarks (C7, T2, T12, L5-S1) and to determine any position dependent variations in regional measures or sagittal balance. SUMMARY OF BACKGROUND DATA: Different techniques for positioning patient's arms are used for 36" lateral radiograph with no data on relative effects. METHODS: A total of 25 scoliosis patients were prospectively studied with 36" lateral radiographs in three positions varying arm location (straight out, partially flexed, and the "clavicle" position). Films were analyzed independently by three surgeons. Vertebral landmarks were scored for clarity; and lordosis, kyphosis, and global balance were analyzed. Statistical analysis was done with a General Estimating Equations model. RESULTS: The overall visualization score for the clavicle position was superior to either the 60 degrees or 90 degrees positions (clavicle vs. 60 degrees, P < 0.0001; clavicle vs. 90 degrees, P < 0.0003). Analysis of vertebral landmarks showed significantly better visualization of T2 with clavicle versus 90 degrees (P < 0.047), better visualization of T12 with clavicle versus either 60 degrees (P < 0.006) or 90 degrees (P < 0.049), and better visualization of L5-S1 with clavicle versus 90 degrees (P < 0.02). Regional measures showed no differences, but sagittal balance was significantly more positive in the 60 degrees position than either clavicle (P < 0.04) or 90 degrees (P < 0.015). CONCLUSIONS: The clavicle position for obtaining lateral 36" radiographs produces significantly better overall visualization of critical vertebral landmarks. Regional measures do not differ between the three positions, but global balance is more positive with the 60 degrees position. Clinically, the clavicle position may result in more accurate radiographic measures and may minimize repeated radiograph exposures.

Adult↗

PubMed2005

A prospective analysis of intraoperative electromyographic monitoring of posterior cervical screw fixation.

OBJECTIVE: This is a prospective study of 26 patients undergoing posterior cervical spine instrumentation with lateral mass or pedicle screws to determine the correlation between intraoperative screw stimulation thresholds and the position of posterior cervical lateral mass and pedicle screws. METHODS: One hundred forty-seven posterior cervical screws (122 lateral mass screws and 25 C7 pedicle screws) in 26 patients were electrically stimulated intraoperatively and stimulation thresholds recorded. Computed tomography (CT) scans were taken postoperatively and were evaluated independently to assess screw position. Electromyographic (EMG) thresholds and CT data were compared to assess the accuracy of the EMG screw stimulation technique in detecting screw malposition. RESULTS: Intraoperative electrical stimulation was accurate in verifying screw position. A stimulation threshold of 15 mA provided a 99% positive predictive value (89% sensitivity, 87% specificity) that the screw was within the lateral mass or pedicle. Stimulation values of 10-15 mA provided a 13% predictive value (66% sensitivity, 90% specificity) that the screw was within the lateral mass or pedicle. A stimulation value of <10 mA provided a 100% predictive value that the screw was malpositioned (70% sensitivity, 100% specificity). CONCLUSIONS: Intraoperative evoked EMG monitoring is a valuable tool in posterior cervical instrumentation using lateral mass and pedicle screws. Stimulation thresholds in this study correlated with screw position. Stimulation values of >15 mA reliably predict acceptable screw position. Values between 10 and 15 mA are generally associated with acceptable screw position, although exploration is recommended. Values below 10 mA are associated with screw malposition and warrant exploration, repositioning, and possible removal.

Bone Screws↗

PubMed2004

Treatment of pyogenic vertebral osteomyelitis with anterior debridement and fusion followed by delayed posterior spinal fusion.

STUDY DESIGN: Case series. OBJECTIVES: The results of surgical treatment of osteomyelitis with anterior debridement and fusion followed by delayed posterior stabilization and fusion are presented. METHODS: Forty-two patients with vertebral osteomyelitis are presented. There were 5 cervical, 12 thoracic, 1 thoracolumbar, 19 lumbar, and 5 lumbosacral lesions. The most frequently identified organism was Staphylococcus aureus. Most patients had significant comorbidities, including diabetes, or were immunocompromised. Ninety percent had elevated erythrocyte sedimentation rates and C-reactive proteins, while white blood cell counts were less reliably elevated. Imaging studies included radiographs, CT scans, and MRIs. All patients were treated with anterior debridement and strut grafting followed by 14.4 days of intravenous antibiotics and delayed instrumented posterior fusions and received 6 weeks of intravenous antibiotics after surgery. RESULTS: All patients had resolution of their infections with no recurrence. There were two deaths. Neurologic deficits resolved in all patients. The diagnosis of pyogenic vertebral osteomyelitis is frequently delayed and presents a significant surgical challenge. The indications for surgical debridement were neurologic compromise, failed medical treatment, soft tissue extension, extensive vertebral body and disc space destruction, and progressive deformity. Many of these patients were severely ill at presentation and required urgent treatment. Anterior debridement and fusion followed by intravenous antibiotics allows for restoration of anterior column support and control of the infection before posterior instrumentation and fusion. CONCLUSION: This study demonstrates that anterior surgical debridement with fusion, followed by a period of intravenous antibiotics and delayed instrumented posterior fusion, is highly effective in the treatment of pyogenic osteomyelitis that has failed medical management.

Adult↗

PubMed2004

Pediatric spine fractures: a review of 137 hospital admissions.

OBJECTIVE: The anatomy and biomechanics of the growing spine produce failure patterns different from those in adults. Spinal injury in the pediatric patient is a concern as prevention of further neurologic damage and deformity and the good potential for recovery make timely identification and appropriate treatment of such injury critical. A retrospective clinical case series was conducted to present data from a large series of pediatric patients with spine injuries from a single regional trauma center. METHODS: One hundred thirty-seven children with spine injuries were seen over 10 years and were divided into three age groups: 0-9, 10-14, and 15-17 years. Analysis of variance and chi2 were used to analyze differences between groups. RESULTS: There were 36 patients aged 0-9, 49 aged 10-14, and 52 aged 15-17. Spine injury incidence increased with age. Motor vehicular accidents were the most common cause in this series. There were 36% cervical, 34% thoracic, 29% lumbar, 34% multilevel contiguous, and 7% multilevel noncontiguous involvement. Nineteen percent had spinal cord injury. Thirteen of 21 complete neurologic injuries and all 3 incomplete injuries improved. Cord injury was more common in the 0-9 age group. Four of five patients with spinal cord injury without radiographic abnormality (SCIWORA) were in the 0-9 age group and had complete neurologic injuries. Young children with cervical injuries were more likely to die than older children. Fifty-three percent had associated injuries. Eighteen percent underwent decompression, fusion, and instrumentation. Two patients developed scoliosis. The complication rate in surgical patients was higher than in patients treated nonsurgically and in polytrauma patients. This may be related to the severity of the initial injury. CONCLUSIONS: Our results suggest age-related patterns of injury that differ from previous work. The incidence of cord injury is 20% with higher frequencies in the young child. Potential for neurologic recovery is good. Young children have a higher risk for death than older children. There was no predominance of cervical injuries in the young child. The incidence of SCIWORA was low. Higher complication rates were seen in polytrauma and surgical patients.

Accidents↗

PubMed2003

Perioperative complications of posterior lumbar decompression and arthrodesis in older adults.

BACKGROUND: Lumbar arthrodesis is commonly done in elderly patients to treat degenerative spine problems. These patients may be at increased risk for complications because of their age and associated medical conditions. In this study, we examined the rates of perioperative complications associated with posterior lumbar decompression and arthrodesis in patients sixty-five years of age or older. METHODS: We reviewed the hospital records of ninety-eight patients who were sixty-five years of age or older when they had a posterior decompression and lumbar arthrodesis with instrumentation, between 1993 and 1995, to treat degenerative disease of the spine. The average age was seventy-two years (range, sixty-five to eighty-four years). RESULTS: Perioperative complications occurred in seventy-eight patients. Twenty-one patients had at least one major complication, and sixty-nine had at least one minor complication. Forty-nine patients had more than one complication. The most common major complication was wound infection (prevalence, 10%), and the most common minor complication was urinary tract infection (prevalence, 34%). The complication rate increased with older age, increased blood loss, longer operative time, and the number of levels of the arthrodesis. CONCLUSIONS: Surgeons should be vigilant about perioperative complications in elderly patients treated with multi-level lumbar decompression and arthrodesis with instrumentation. Elderly patients should be made aware that they are at increased risk for surgical complications because of their age. Attention should be paid to controlling blood loss and limiting operative time.

Aged↗