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Curtis A Dickman

Publications and source records attributed to Curtis A Dickman.

At least 19 recordsLinked to original sources
PubMed2006

Biomechanical assessment of anterior lumbar interbody fusion with an anterior lumbosacral fixation screw-plate: comparison to stand-alone anterior lumbar interbody fusion and anterior lumbar interbody fusion with pedicle screws in an unstable human cadaver model.

STUDY DESIGN: Human lumbosacral cadaveric specimens were tested in an in vitro biomechanical flexibility experiment using physiologic loads in 5 sequential conditions. OBJECTIVE: To determine the biomechanical differences between anterior lumbar interbody fusion (ALIF) using cylindrical threaded cages alone or supplemented with an anterior screw-plate or posterior pedicle screws-rods. SUMMARY OF BACKGROUND DATA: Clinically and biomechanically, stand-alone ALIF performs modestly in immobilizing the unstable spine. Pedicle screws improve fixation stiffness significantly, but supplementary anterior instrumentation has not been studied. METHODS: There were 7 specimens tested: (1) intact, (2) after discectomy and facetectomy to induce moderate rotational and translational hypermobility, (3) with 2 parallel ALIF cages, (4) with cages plus a triangular anterior screw-plate, and (5) with cages plus pedicle screws-rods. Pure moments without preload induced flexion, extension, lateral bending, and axial rotation; linear shear forces induced anteroposterior translation. Angular and linear motions were measured stereophotogrammetrically, and range of motion (ROM) and stiffness were quantified. RESULTS: Compared to the destabilized spine, interbody cages alone reduced ROM by 77% during flexion, 53% during extension, 60% during lateral bending, 69% during axial rotation, and 71% during anteroposterior shear (P < 0.001, analysis of variance/Fisher least significant difference). Addition of an anterior plate or pedicle screws-rods, respectively, further reduced ROM by 8% or 13% during flexion (P = 0.21), 21% or 28% during extension (P = 0.15), 5% or 25% during lateral bending (P = 0.04), 11% or 18% during axial rotation (P = 0.13), and 18% or 18% during anteroposterior shear (P = 0.17). Compared to stand-alone ALIF, both the anterior screw-plate and pedicle screw-rod fixation reduced vertebral ROM to less than 1.2 degrees of rotation and less than 0.1 mm of translation. CONCLUSIONS: The anterior screw-plate and pedicle screws-rods both substantially reduced ROM and increased stiffness compared to stand-alone interbody cages. There was no significant difference in the amount by which the supplementary fixation devices limited flexion, extension, axial rotation, or anteroposterior shear; pedicle screws-rods better restricted lateral bending.

Aged↗
PubMed2006

Congenital cervical instability in a patient with camptomelic dysplasia.

INTRODUCTION: Camptomelic dysplasia (CD) is a rare autosomal dominant skeletal dysplasia classically characterized by bent bones of the extremities, tracheobronchial narrowing, thoracic kyphoscoliosis, and various degrees of phenotypic sex reversal. Most patients die of complications in infancy, although long-term survivors have been reported. CASE REPORT: We report a case of CD complicated by incomplete ossification of the cervical vertebral pedicles, resulting in congenital cervical instability and kyphosis. Closed reduction was performed, and the patient was fitted with a customized cervical orthosis. FINDING: He subsequently developed a complete spinal cord injury at the kyphotic level. This underscores the grim prognosis associated with neonatal cervical spinal instability.

Adult↗
PubMed2006

Retroperitoneal approach for lumbar interbody fusion with anterolateral instrumentation for treatment of spondylolisthesis and degenerative foraminal stenosis.

BACKGROUND: An alternative approach for the treatment of the degenerative or unstable lumbar spine using retroperitoneal lateral LIF with anterolateral screw-plate or screw-rod fixation is introduced. Special attention is given to application of this procedure in patients who have undergone prior lumbar surgery. METHODS: Between 1998 and 2001, 14 patients underwent lateral LIF with anterolateral instrumentation to treat degenerative foraminal stenosis or spondylolisthesis. Eleven patients (79%) had undergone prior posterior lumbar surgery, 7 of whom were also fused at that time. All patients first presented with mechanical back pain, radicular pain, or both. The mean follow-up was 21 months (range, 8 to 36 months). RESULTS: Radicular pain and mechanical back pain significantly improved in 71% and 54% of patients, respectively. Of the 9 patients with preoperative neurological deficits, 7 were intact or had improved at their follow-up examination. One patient developed postoperative radiculopathy contralateral to his original symptoms. Radiography confirmed good positioning of the hardware and evidence of fusion in all 14 patients. No major complications occurred. CONCLUSIONS: Retroperitoneal lateral LIF with anterolateral instrumentation is an attractive alternative for the treatment of the degenerative or unstable lumbar spine in the absence of significant spinal stenosis. This approach is particularly useful for treating spondylolisthesis or degenerative foraminal stenosis in the postoperative lumbar spine.

Aged↗
PubMed2006

A biomechanical comparison of three anterior thoracolumbar implants after corpectomy: are two screws better than one?

OBJECT: A flexibility experiment using human cadaveric thoracic spine specimens was performed to determine biomechanical differences among thoracolumbar two-screw plate, single-screw plate, and dual-rod systems. A secondary goal was to investigate differences in the ability of the systems to stabilize the spine after a one- or two-level corpectomy. METHODS: The authors evaluated 21 cadaveric spines implanted with a titanium mesh cage and three types of anterior thoracolumbar supplementary instrumentation after one-level thoracic corpectomies. Pure moments were applied quasistatically while three-dimensional motion was measured optoelectronically. The lax zone, stiff zone, and range of motion (ROM) were measured during flexion, extension, left and right lateral bending, and left and right axial rotation. Corpectomies were expanded to two levels, and testing was repeated with longer hardware. Biomechanical testing showed that the single-bolt plate system was no different from the dual-rod system with two screws in limiting ROM. The single-bolt plate system performed slightly better than the two-screw plate system. Across the same two levels, there was an average of 19% more motion after a two-level corpectomy than after a one-level corpectomy. In general, however, the difference across the different loading modes was insignificant. CONCLUSIONS: Biomechanically, the single-screw plate system is equivalent to a two-screw dual-rod and a two-screw plate system. All three systems performed similarly in stabilizing the spine after one- or two-level corpectomies.

Adult↗
PubMed2006

Complications of halo fixation in the elderly.

OBJECT: The risk factors of halo fixation in elderly patients have never been analyzed. The authors therefore retrospectively reviewed data obtained in the treatment of such cases. METHODS: A discharge database was searched for patients 70 years of age or older who had undergone placement of a halo device. In a search of cases managed between April 1999 and February 2005, data pertaining to 53 patients (mean age 79.9 years [range 70-97 years]) met these criteria. Forty-one patients were treated for traumatic injuries. Ten patients had deficits ranging from radiculopathy to quadriparesis, and 43 had no neurological deficit. Adequate follow-up material was available in 42 patients (mean treatment duration 91 days). Halo immobilization was the only treatment in 21 patients, and adjunctive surgical fixation was undertaken in the other 21 patients. There were 31 complications in 22 patients: respiratory distress in four patients, dysphagia in six, and pin-related complications in 10. Eight patients died; in two of these cases, the cause of death was clearly unrelated to the halo brace. The other six patients died of respiratory failure and cardiovascular collapse (perioperative mortality rate 14%). Three patients who died had sustained acute trauma and three had undergone surgical stabilization. CONCLUSIONS: External halo fixation can be used safely to treat cervical instability in elderly patients. The high complication rate in this population may reflect the significant incidence of underlying disease processes.

Age Factors↗
PubMed2006

Durectomy and reconstruction for the treatment of a recurrent spinal meningioma. Case report.

The management of spinal meningiomas with extensive involvement of the dura mater is controversial. The principal difficulty in performing a resection is the potential for complications associated with this approach. The authors present the case of a pregnant 35-year-old woman in whom bilateral lower-extremity numbness, weakness, gait ataxia, and myelopathy developed. Magnetic resonance imaging showed a recurrent thoracic meningioma with extensive infiltration of the dura mater. Durectomy, complete resection, and reconstruction were performed. The patient has not experienced a recurrence 21 months after her treatment. This case illustrates that thoracic spinal meningiomas with extensive dural involvement can be resected safely with a complete durectomy. The novel dural reconstruction involving the implantation of a fascia lata and bovine pericardium allograft is an effective way to reconstruct the dura to create an adequate barrier to cerebrospinal fluid.

Adult↗
PubMed2005

Effect of recombinant human bone morphogenetic protein-2 in an experimental model of spinal fusion in a radiated area.

STUDY DESIGN: An animal model of posterolateral intertransverse process spine fusion was used. OBJECTIVES: To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) can overcome the adverse effects of radiation treatment (RT) on spine fusion. SUMMARY OF BACKGROUND DATA: Spinal metastases are common. Some of these patients are candidates for spinal cord decompression and vertebral reconstruction; however, radiation has significant adverse effects on bone healing. METHODS: A posterolateral fusion model was used with rhBMP-2 or iliac crest bone graft (ICBG). Eighty one-year-old rabbits were divided into eight groups: 1) RT 14 days before surgery, rhBMP-2; 2) RT 14 days before surgery, ICBG; 3) RT 2 days after surgery, rhBMP-2; 4) RT 2 days after surgery, ICBG; 5) RT 14 days after surgery, rhBMP-2; 6) RT 14 days after surgery, ICBG; 7) no RT, rhBMP-2; 8) no RT, ICBG. Animals were killed approximately 35 days after surgery. Manual palpation was the definitive test of fusion. Biomechanical and histologic assessments were also performed. RESULTS: All rhBMP-2 groups had significantly greater fusion rates versus respective ICBG control groups: 1 (86%) versus 2 (0%) (P = 0.005), 3 (100%) versus 4 (0%) (P < 0.0001), 5 (100%) versus 6 (0%) (P < 0.0001), and 7 (100%) versus 8 (60%) (P = 0.003). Stiffness and ultimate strength did not differ significantly between the experimental and control groups. Histologic assessment confirmed new bone formation in the fusion masses from rhBMP-2 groups. CONCLUSIONS: Use of rhBMP-2 produced a significantly greater rate of fusion compared with ICBG in a previously radiated area in an animal model, without the morbidity of ICBG harvesting and without the risk of inadvertently using autograft contaminated by micrometastases.

Animals↗
PubMed2005

Unilateral cervical facet dislocation: biomechanics of fixation.

STUDY DESIGN: Unilateral facet dislocation was created in human cadaveric cervical spines. Specimens were sequentially instrumented with posterior or anterior screws and plates, and studied biomechanically. OBJECTIVE: To determine the biomechanical differences between anterior and posterior fixation for stabilization of a reduced unilateral cervical facet dislocation. SUMMARY OF BACKGROUND DATA: Although previous studies have compared anterior to posterior instrumentation, no data exist on the biomechanics of either type of stabilization after this particular injury. METHODS: In 6 human cadaveric cervical spine segments, a reproducible unilateral facet dislocation was created and then unlocked (reduced). Nondestructive torques were applied to specimens that were intact, injured-reduced, fixated using posterior nonlocking lateral mass plates, and fixated using a bone graft plus an anterior nonlocking plate. Flexion, extension, lateral bending, and axial rotation were measured stereophotogrammetrically. RESULTS: Lateral mass plating was more effective than anterior plating in limiting motion after reduction of a unilateral facet dislocation. Averaged, over all loading directions, lateral mass plates reduced the range of motion to 17% of normal; anterior plates reduced range of motion to 89% of normal. In all loading directions, lateral mass plates performed significantly better than anterior plates (P < 0.05, paired Student t-tests). CONCLUSIONS: Anterior and posterior plating effectively stabilized a reduced unilateral facet dislocation. Lateral mass fixation provided better immobilization than anterior graft and plate.

Adult↗
PubMed2005

Biomechanical comparison of anterior versus posterior lumbar threaded interbody fusion cages.

STUDY DESIGN: Biomechanical flexibility tests were performed in specimens receiving anterior lumbar interbody fixation or posterior lumbar interbody fixation using dual threaded cages. OBJECTIVES: To determine differences in stability between anterior lumbar interbody fixation and posterior lumbar interbody fixation immediately after surgery and after fatigue. SUMMARY OF BACKGROUND DATA: No direct biomechanical comparison of lumbar fixation with threaded anterior lumbar interbody fixation or posterior lumbar interbody fixation cages has been performed previously. METHODS.: Sixteen anterior lumbar interbody fixation specimens and 16 posterior lumbar interbody fixation specimens underwent nondestructive biomechanical testing. Flexibility was assessed during applied flexion, extension, lateral bending, axial rotation, and anteroposterior shear before and after fixation and fatigue. After testing, specimens were dissected, and the quality of fixation was graded. RESULTS: Variability in angular range of motion after fixation was greater than normal interspecimen variability by 89% after anterior lumbar interbody fixation and by 117% after posterior lumbar interbody fixation. During flexion-extension and lateral bending, posterior lumbar interbody fixation allowed a mean of 60% smaller neutral zones than anterior lumbar interbody fixation (P < 0.05, nonpaired Student t test). During axial rotation, anterior lumbar interbody fixation allowed 15% less range of motion than posterior lumbar interbody fixation unless facets were kept intact with posterior lumbar interbody fixation (6 of 16 specimens), in which case anterior lumbar interbody fixation allowed 41% greater range of motion than posterior lumbar interbody fixation. During anteroposterior shear, both anterior lumbar interbody fixation and posterior lumbar interbody fixation restrained range of motion to within 50% of normal. Anterior lumbar interbody fixation loosened, on average, 130% more with fatigue than posterior lumbar interbody fixation during anteroposterior shear. CONCLUSIONS: Both anterior lumbar interbody fixation and posterior lumbar interbody fixation provided inconsistent stability. Therefore, stand-alone anterior lumbar interbody fixation or posterior lumbar interbody fixation may often be ineffective clinically. During all modes of loading except axial rotation, posterior lumbar interbody fixation performed slightly better than anterior lumbar interbody fixation, perhaps due to deeper hole preparation and destruction of anterior stabilizers necessary for anterior lumbar interbody fixation. Avoiding resection of facets during posterior lumbar interbody fixation led to significantly better performance during axial rotation.

Biomechanical Phenomena↗
PubMed2005

Pars screw fixation of a hangman's fracture: technical case report.

OBJECTIVE AND IMPORTANCE: Traumatic spondylolisthesis of the axis may be treated by external immobilization or surgical fixation. CLINICAL PRESENTATION: We report the case of a 23-year-old man who sustained an Effendi Type II fracture of the axis, for which halo immobilization did not provide adequate stability. INTERVENTION: The unstable fracture was treated by placing lag screws in the pars interarticularis of C2, which reduced the fracture directly but sacrificed no normal spinal motion. The patient developed a solid fusion, and cervical alignment was normal at his 6-month follow-up examination. CONCLUSION: Although this technique has been reported previously, it is more commonly used in multilevel cervical fusions than for stand-alone repair of C2. Management options, anatomy, and technical considerations for the treatment of traumatic spondylolisthesis are reviewed.

Adult↗
PubMed2005

Atlantooccipital transarticular screw fixation for the treatment of traumatic occipitoatlantal dislocation. Technical note.

The authors describe a new technique of internal atlantooccipital screw fixation involving posterior wiring and fusion for the treatment of traumatic atlantooccipital dislocation, which was performed in a 17-year-old male patient involved in a motor vehicle accident and who suffered from atlantooccipital dislocation without neurological injury. At the 6-month follow-up examination, the patient was neurologically intact with a solid occipitocervical fusion and full range of motion of the neck.

Accidents, Traffic↗
PubMed2005

Surgical management of giant herniated thoracic discs: analysis of 20 cases.

OBJECT: The authors evaluated the clinical and surgical outcomes obtained in patients with giant herniated thoracic discs (HTDs), defined as occupying more than 40% of the spinal canal. Surgery-related considerations and functional outcomes in patients with small- and medium-sized HTDs were compared. METHODS: The authors reviewed 140 cases of surgically treated HTDs, 20 (14%) of which were giant. Before and after surgery, all patients underwent computerized tomography myelography, magnetic resonance imaging, or both. Functional outcomes were assessed using the Frankel grading system preoperatively, immediately after surgery, and at long-term follow-up examination. The results observed in patients with giant HTDs were compared with those with small- and medium-sized HTDs. The mean overall follow-up period was 2.6 years. Sixty-six patients (47%) presented with myelopathy, including 19 (95%) with a giant HTD. Of the latter, 16 (80%) underwent anterior, eight thoracoscopic, and eight open thoracotomy approaches. Four patients (20%) with laterally oriented giant HTDs within the spinal canal underwent surgery via a posterolateral approach. Based on analysis of long-term follow-up data, 53% of patients with giant HTDs improved neurologically by one Frankel grade. Progression of myelopathy was arrested in 42%, and in 5% the Frankel grade worsened by one. In patients with small- and medium-sized HTDs, the Frankel grade improved by one in 77%, stabilized in 23%, and worsened in 0%. Patients with giant HTDs who underwent thoracoscopic surgery had worse short- and long-term functional outcomes than those in whom open thoracotomy was performed. CONCLUSIONS: Patients with giant HTDs presented more frequently with myelopathy and experienced worse functional outcomes than those with smaller HTDs. Based on their experience, the authors recommend open thoracotomy rather than thoracoscopy for the treatment of midline giant HTDs.

Adult↗
PubMed2005

Use of dual transarticular screws to fixate simultaneous occipitoatlantal and atlantoaxial dislocations.

Occipitoatlantal dislocation and atlantoaxial vertical distraction are caused by similar mechanisms, and few individuals survive these injuries. It is hypothesized that the injurious vertical force manifests as a traumatic lesion at different levels of the same ligamentous complex. The authors report the cases of two patients who presented with this combined lesion, describe surgical alternatives for stabilization, and introduce a new technique that combines the use of transarticular screws in a "dual" construct, without involving the unaffected spine.

Accidents, Traffic↗
PubMed2004

Intraoperative Iso-C C-arm navigation in cervical spinal surgery: review of the first 52 cases.

STUDY DESIGN: Fifty-two study participants underwent cervical spine surgery using intraoperative Iso-C imaging with or without spinal navigation. OBJECTIVES: To evaluate prospectively the feasibility, advantages, limitations, and applications of Iso-C in cervical spine surgery. SUMMARY OF BACKGROUND DATA: Existing stereotactic spinal navigational systems images must be acquired before surgery and typically require cumbersome point-to-point registration. Intraoperative computed tomography (CT) and magnetic resonance imaging (MRI) provide real-time information but can restrict access to the patient, preclude the use of traditional operating room tables, and are time-consuming. The Iso-C allows quick, CT-quality, real-time data acquisition without restricting access to the patient. The data acquired can be automatically transferred to navigational systems with the immediate ability to navigate for anterior or posterior cervical spine procedures. METHODS: High-resolution isotropic three-dimensional data sets were acquired using the Iso-C intraoperative fluoroscopy in 52 cervical spine cases. In 30 cases, the data were imported automatically to the StealthStation Treon to support neuronavigation. In 22 cases, a postprocedural intraoperative CT was obtained with the Iso-C primarily to assess the extent of osseous decompression and/or the accuracy of implants or instrumentation. In most cases, a postoperative high-resolution CT image was obtained and compared with the Iso-C data. RESULTS: Successful automated registration suitable for navigation was attained for all anterior and posterior cervical spinal cases. The postprocedural intraoperative Iso-C data were 100% concordant with those of postoperative high-resolution CT as determined by a blinded neuroradiologist. CONCLUSIONS: Iso-C intraoperative fluoroscopy is an accurate and rapid way to perform CT-quality image-guided navigation in cervical spinal surgery. In most cases, it obviates the need for postoperative imaging.

Adolescent↗
PubMed2004

Biomechanical comparison of anterolateral plate, lateral plate, and pedicle screws-rods for enhancing anterolateral lumbar interbody cage stabilization.

STUDY DESIGN: A repeated measures in vitro flexibility experiment was performed in calf spines. OBJECTIVES: To determine the biomechanical differences among three techniques for augmenting stability of an anterolateral lumbar threaded interbody cage. BACKGROUND: Stand-alone interbody cages are known to inadequately stabilize the spine. Surgeons often add supplementary instrumentation for a more stable construct. METHODS: Six L2-L5 calf spines (L3-L4 level instrumented) were tested: 1) intact; 2) with a single anterolateral interbody cage; 3) with cage plus anterolateral plating; 4) with cage plus lateral plating; and 5) with cage plus pedicle screw fixation. Specimens were loaded in each anatomic plane quasistatically (maximum 5.0 Nm). Angular motion was measured stereophotogrammetrically. RESULTS: The stand-alone interbody cage allowed significantly less range of motion than normal during all loading modes except axial rotation. Addition of pedicle screws-rods, anterolateral plate, or lateral plate significantly further reduced range of motion in all planes. Pedicle screws slightly outperformed the anterolateral plate during extension and lateral bending and slightly outperformed the lateral plate during flexion, extension, and left axial rotation (range of motion differences <0.65 degrees, P < 0.05). The anterolateral plate outperformed the lateral plate during flexion and extension, whereas the lateral plate outperformed the anterolateral plate during lateral bending (range of motion difference <0.57 degrees, P < 0.05). CONCLUSION: Anterolateral or lateral lumbar plating increases stability significantly compared to stand-alone interbody cage fixation. These findings support anterolateral or lateral plate fixation as a potential clinical alternative to pedicle screws-rods in this role and may obviate the need for combined anterior and posterior approaches when spinal instability exists.

Animals↗
PubMed2004

Anterior lumbar interbody fusion for treatment of failed back surgery syndrome: an outcome analysis.

OBJECTIVE: Anterior lumbar interbody fusion (ALIF) has gained popularity for the treatment of degenerative disease of the lumbar spine. In this report, we present our experience with the ALIF procedure for treatment of failed back surgery syndrome (FBSS) in a noncontrolled prospective cohort. METHODS: In a 2-year period, we treated patients diagnosed with FBSS with ALIF. Clinical and radiological outcomes were recorded in a prospective, nonrandomized, longitudinal manner. Neurological, pain, and functional outcomes were measured preoperatively and 12 months after surgery. Operative data, perioperative complications, and radiological and clinical outcomes were recorded. RESULTS: Thirty-three patients with a preoperative diagnosis of FBSS, with degenerative disc disease (n = 17), postsurgical spondylolisthesis (n = 13), or pseudarthrosis (n = 3), underwent ALIF. Back pain, leg pain, and functional status improved significantly, by 76% (P < 0.01), 80% (P < 0.01), and 67% (P < 0.01), respectively. CONCLUSION: On the basis of our results, we found ALIF to be a safe and effective procedure for the treatment of FBSS for selected patients.

Activities of Daily Living↗
PubMed2004

Thoracoscopic placement of dual-rod instrumentation in thoracic spinal trauma.

OBJECTIVE AND IMPORTANCE: Traditionally, thoracic fractures that require anterior stabilization are treated through an open thoracotomy approach. Thoracoscopic instrumentation avoids many of the complications associated with an open thoracotomy but is technically challenging. We report the first cases of dual-rod internal fixation systems placed thoracoscopically for thoracic spinal trauma. CLINICAL PRESENTATION: Two male patients sustained midthoracic spinal trauma falling from motorcycles in separate incidents. Both injuries led to unstable spinal columns, but the patients had no neurological deficits and had minimal spinal cord compression. One patient had a complex spiral fracture from T6 to T8; the other had T7 burst and T8 compression fractures. Based on the complex morphological features of the patients' fractures, anterior internal fixation was the treatment of choice for both. The two available options for an anterior stabilization were open thoracotomy and thoracoscopic instrumentation. Because extensive decompression was unnecessary, a thoracoscopic approach was used. INTERVENTION: A dual-rod internal fixation system (Medtronic Sofamor Danek, Inc., Memphis, TN) was placed with two screws each in the T6 and T9 vertebral bodies of each patient. Thoracoscopy was used for direct visualization of the operative site with fluoroscopic guidance for screw placement. Surgery was completed without complications, and both patients did well afterward. Upright and supine x-rays demonstrated that the constructs were stable at 10 weeks and 6 months, respectively. CONCLUSION: Thoracoscopic instrumentation offers the advantages of a minimally invasive approach but is technically challenging. The characteristics of dual-rod fixation systems (small-profile components and step-wise insertion) provide the best biomechanical profile and facilitate thoracoscopic instrumentation.

Adult↗