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5:52 132. Early complications of anterior cervical decompression with posterior instrumented fusion across the cervicothoracic junction
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S the distal type were inferior to the proximal type. Erb-point stimulated compound muscle action potentials appeared to correlate with the possibility of the postoperative muscle recovery. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2005.05.133
5:52 132. Early complications of anterior cervical decompression with posterior instrumented fusion across the cervicothoracic junction Robert Tatsumi, MD*, Robert Hart, MD; Oregon Health & Science University, Portland, OR, USA BACKGROUND CONTEXT: Surgical treatment of multiple level cervical degenerative disease with kyphosis is often treated with anterior decompression and posterior instrumented fusion. Appropriate levels for ending posterior cervical fusion have not been well documented. We have increasingly used posterior constructs crossing the C7-T1 junction in order to prevent junctional breakdown and improve fixation at the distal end of the arthrodesis. PURPOSE: We sought to review the early peri-operative complications with this approach and compare them to reported complication rates for anterior/posterior spine fusion. STUDY DESIGN/SETTING: A retrospective review of thirteen patients who underwent a multi-level arthrodesis spanning the cervico-thoracic junction between 1999 and 2003 with at least one year follow-up was conducted. PATIENT SAMPLE: Eleven patients had multi-level degenerative disease with kyphosis. One each had an infection with an epidural abscess and neurofibromatosis with kyphosis and spinal stenosis.. All thirteen patients underwent anterior cervical discectomy and corpectomy with simultaneous posterior instrumentation and fusion to T1, T2, or T3. Posterior instrumentation constructs included 3.0 mm rods extended from cervical lateral mass screws to upper thoracic 3.5 mm diameter pedicle screws, changing to 3.0 mm cervical rods dominoed to 5.5 mm rods attached to 5.0 mm upper thoracic pedicle screws later in the series. OUTCOME MEASURES: All early complications were reviewed and recorded as major or minor depending on the severity and need for further intervention. METHODS: Retrospective review of patients undergoing anterior posterior reconstruction of cervical spine extending past C7/T1 junction. An analysis of peri-operative complications of this patient group is performed. RESULTS: A total of 10 complications were recorded in seven of thirteen patients (54%). Six minor complications occurred including postoperative delirium (1), halo ring dislodgement (1), anterior graft migration not requiring revision (1), patient re-intubation (4), and posterior dural tear (1). Major complications included recurrent laryngeal nerve palsy requiring vocal cord stabilization (1), esophageal dysmotility requiring temporary percutaneous gastrostomy (2), iliac crest site infection (1) and postoperative myocardial inarction with recovery (1). There were no neurological injuries nor failures of instrumentation requiring revision. CONCLUSIONS: Surgical treatment of multiple level cervical degenerative disease treated with anterior decompression and posterior instrumented fusion crossing the cervico-thoracic junction has significant complications. In our series, most of these complications were minor, although several did require further intervention. Respiratory complications were frequently encountered and warranted extended postoperative intubation and intensive care unit observation. It appears that patients with combined anteriorposterior cervico-thoracic fusions have manageable but significant perioperative complications, comparable to those observed in anterior-posterior spinal surgery of the thoraco-lumbar spine in adults. The benefits of extending fusions past the cervico-thoracic junction requires longer term comparisons to other surgical approaches to assess its value in treating multi-level cervical stenosis with kyphosis. DISCLOSURES: FDA device/drug: Thoracic Pedicle Screws. Status: Approved for this indication.
69S
CONFLICT OF INTEREST: Author (RH) Speaker’s Bureau Member: Depuy Spine; Author (RH) Grant Research Support: Depuy Spine. doi: 10.1016/j.spinee.2005.05.134
5:58 133. Anterior cervical fusion with variable angle screw instrumentation: selective subsidence and lordosis progression Chad Crawley, DO1, William Beutler, MD2, Walter Peppleman, Jr., DO3, Matthew Espenshade, DO4; 1Harrisburg, PA, USA; 2Pennsylvania Spine Institute, Harrisburg, PA, USA; 3The Arlington Group, Harrisburg, PA, USA; 4Harrisburg, PA, USA BACKGROUND CONTEXT: Anterior cervical plating system choices include dynamic or static plates as well as fixed or variable angle fixation screws. Studies are available which show compression of interbody graft with dynamic plating systems. However, there has been no study of whether there is indeed change in angulation of variable angle screws postoperatively. Variable angle screw fixation has the theoretical opportunity to allow selective posterior compression of the graft with lordotic change. PURPOSE: This prospective, consecutive study seeks to evaluate any vertebral body subsidence in anterior cervical discectomy fusion (ACDF) with variable angle screws. Multiple reports delineate subsidence with dynamic plates. This study seeks to evaluate subsidence with static plates with variable angle screws. STUDY DESIGN/SETTING: The study evaluates a prospective, consecutive series of ACDF procedures, completed by a single surgeon. All procedures were completed with a static plate and variable angle screws with fibula allograft. PATIENT SAMPLE: A total of 53 consecutive procedures were studied. There were 32 men and 21 women. The average age for the study group was 49. There were 36 single-level, 15 two-level, and 2 three-level procedures. OUTCOME MEASURES: Postoperative two-week, two-month, and sixmonth films were studied. METHODS: Lateral X-rays were reviewed by two surgeons independent of the operative surgeon. The anterior and posterior distance from the superior end plate just above the fusion to the inferior end plate below the fusion was obtained. Lordosis was measured by using the Cobb angle between the end plates. If there was vertebral subsidence greater than 2mm anteriorly, then the site of the change was determined. RESULTS: Solid fusion was noted with bridging bone without lucency by the six-month follow-up in all patients. Vertebral body subsidence was noted in all but 8 cases. Subsidence averaged 2 mm posteriorly and 1 mm anteriorly for the series. Posterior subsidence averaged 1 mm for single level fusions, 2.4 mm for 2 level fusions, and 4 for the 3 level fusions. There were 8 cases with ⬎2 mm anterior subsidence, the subsidence occurred at the superior end of the construct in 6. Lordosis was worse only in one patient, and was unchanged in 14. Lordosis was improved with subsidence in 38 patients. Any increase in lordosis was directly related to the degree of posterior subsidence (p⫽.0001, linear regression/two-tailed). There was also a direct relationship between the number of fused levels and the degree of vertebral body settling posteriorly (p⫽.007) and anteriorly (p⫽.01). If there was subsidence posteriorly, then there was a correlation with the degree of anterior subsidence (p⬍.0001). There was no association with the number of levels fused and any improvement with lordosis. The greatest degree of subsidence occurred within the first two months, with little progression beyond this point. Posterior subsidence was accompanied by a change in angulation of the variable angle screws. CONCLUSIONS: Subsidence postoperatively is seen in 85% of variable angle screw constructs, with subsidence selectively posteriorly on the interbody graft. Subsidence averages 2mm posteriorly, and is strongly related to a concomitant increase in lordosis. Vertebral body subsidence anteriorly or posteriorly is directly related to the number of levels fused. Anterior cervical fusion with variable angle screws is associated with subsidence which selectively allows lordotic improvement. In some patients this may be preferred over a dynamic plating system.
5:52 132. Early complications of anterior cervical decompression with posterior instrumented fusion across the cervicothoracic junction Robert Tatsumi, MD*, Robert Hart, MD; Oregon Health & Science University, Portland, OR, USA BACKGROUND CONTEXT: Surgical treatment of multiple level cervical degenerative disease with kyphosis is often treated with anterior decompression and posterior instrumented fusion. Appropriate levels for ending posterior cervical fusion have not been well documented. We have increasingly used posterior constructs crossing the C7-T1 junction in order to prevent junctional breakdown and improve fixation at the distal end of the arthrodesis. PURPOSE: We sought to review the early peri-operative complications with this approach and compare them to reported complication rates for anterior/posterior spine fusion. STUDY DESIGN/SETTING: A retrospective review of thirteen patients who underwent a multi-level arthrodesis spanning the cervico-thoracic junction between 1999 and 2003 with at least one year follow-up was conducted. PATIENT SAMPLE: Eleven patients had multi-level degenerative disease with kyphosis. One each had an infection with an epidural abscess and neurofibromatosis with kyphosis and spinal stenosis.. All thirteen patients underwent anterior cervical discectomy and corpectomy with simultaneous posterior instrumentation and fusion to T1, T2, or T3. Posterior instrumentation constructs included 3.0 mm rods extended from cervical lateral mass screws to upper thoracic 3.5 mm diameter pedicle screws, changing to 3.0 mm cervical rods dominoed to 5.5 mm rods attached to 5.0 mm upper thoracic pedicle screws later in the series. OUTCOME MEASURES: All early complications were reviewed and recorded as major or minor depending on the severity and need for further intervention. METHODS: Retrospective review of patients undergoing anterior posterior reconstruction of cervical spine extending past C7/T1 junction. An analysis of peri-operative complications of this patient group is performed. RESULTS: A total of 10 complications were recorded in seven of thirteen patients (54%). Six minor complications occurred including postoperative delirium (1), halo ring dislodgement (1), anterior graft migration not requiring revision (1), patient re-intubation (4), and posterior dural tear (1). Major complications included recurrent laryngeal nerve palsy requiring vocal cord stabilization (1), esophageal dysmotility requiring temporary percutaneous gastrostomy (2), iliac crest site infection (1) and postoperative myocardial inarction with recovery (1). There were no neurological injuries nor failures of instrumentation requiring revision. CONCLUSIONS: Surgical treatment of multiple level cervical degenerative disease treated with anterior decompression and posterior instrumented fusion crossing the cervico-thoracic junction has significant complications. In our series, most of these complications were minor, although several did require further intervention. Respiratory complications were frequently encountered and warranted extended postoperative intubation and intensive care unit observation. It appears that patients with combined anteriorposterior cervico-thoracic fusions have manageable but significant perioperative complications, comparable to those observed in anterior-posterior spinal surgery of the thoraco-lumbar spine in adults. The benefits of extending fusions past the cervico-thoracic junction requires longer term comparisons to other surgical approaches to assess its value in treating multi-level cervical stenosis with kyphosis. DISCLOSURES: FDA device/drug: Thoracic Pedicle Screws. Status: Approved for this indication.
69S
CONFLICT OF INTEREST: Author (RH) Speaker’s Bureau Member: Depuy Spine; Author (RH) Grant Research Support: Depuy Spine. doi: 10.1016/j.spinee.2005.05.134
5:58 133. Anterior cervical fusion with variable angle screw instrumentation: selective subsidence and lordosis progression Chad Crawley, DO1, William Beutler, MD2, Walter Peppleman, Jr., DO3, Matthew Espenshade, DO4; 1Harrisburg, PA, USA; 2Pennsylvania Spine Institute, Harrisburg, PA, USA; 3The Arlington Group, Harrisburg, PA, USA; 4Harrisburg, PA, USA BACKGROUND CONTEXT: Anterior cervical plating system choices include dynamic or static plates as well as fixed or variable angle fixation screws. Studies are available which show compression of interbody graft with dynamic plating systems. However, there has been no study of whether there is indeed change in angulation of variable angle screws postoperatively. Variable angle screw fixation has the theoretical opportunity to allow selective posterior compression of the graft with lordotic change. PURPOSE: This prospective, consecutive study seeks to evaluate any vertebral body subsidence in anterior cervical discectomy fusion (ACDF) with variable angle screws. Multiple reports delineate subsidence with dynamic plates. This study seeks to evaluate subsidence with static plates with variable angle screws. STUDY DESIGN/SETTING: The study evaluates a prospective, consecutive series of ACDF procedures, completed by a single surgeon. All procedures were completed with a static plate and variable angle screws with fibula allograft. PATIENT SAMPLE: A total of 53 consecutive procedures were studied. There were 32 men and 21 women. The average age for the study group was 49. There were 36 single-level, 15 two-level, and 2 three-level procedures. OUTCOME MEASURES: Postoperative two-week, two-month, and sixmonth films were studied. METHODS: Lateral X-rays were reviewed by two surgeons independent of the operative surgeon. The anterior and posterior distance from the superior end plate just above the fusion to the inferior end plate below the fusion was obtained. Lordosis was measured by using the Cobb angle between the end plates. If there was vertebral subsidence greater than 2mm anteriorly, then the site of the change was determined. RESULTS: Solid fusion was noted with bridging bone without lucency by the six-month follow-up in all patients. Vertebral body subsidence was noted in all but 8 cases. Subsidence averaged 2 mm posteriorly and 1 mm anteriorly for the series. Posterior subsidence averaged 1 mm for single level fusions, 2.4 mm for 2 level fusions, and 4 for the 3 level fusions. There were 8 cases with ⬎2 mm anterior subsidence, the subsidence occurred at the superior end of the construct in 6. Lordosis was worse only in one patient, and was unchanged in 14. Lordosis was improved with subsidence in 38 patients. Any increase in lordosis was directly related to the degree of posterior subsidence (p⫽.0001, linear regression/two-tailed). There was also a direct relationship between the number of fused levels and the degree of vertebral body settling posteriorly (p⫽.007) and anteriorly (p⫽.01). If there was subsidence posteriorly, then there was a correlation with the degree of anterior subsidence (p⬍.0001). There was no association with the number of levels fused and any improvement with lordosis. The greatest degree of subsidence occurred within the first two months, with little progression beyond this point. Posterior subsidence was accompanied by a change in angulation of the variable angle screws. CONCLUSIONS: Subsidence postoperatively is seen in 85% of variable angle screw constructs, with subsidence selectively posteriorly on the interbody graft. Subsidence averages 2mm posteriorly, and is strongly related to a concomitant increase in lordosis. Vertebral body subsidence anteriorly or posteriorly is directly related to the number of levels fused. Anterior cervical fusion with variable angle screws is associated with subsidence which selectively allows lordotic improvement. In some patients this may be preferred over a dynamic plating system.