Biomedical subjects

Mitchell J Campbell

Publications and source records attributed to Mitchell J Campbell.

6 recordsLinked to original sources

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

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

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

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↗

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↗