- Email: [email protected]
Prophylactic Vertebroplasty of Adjacent Nonfused Segment(s): Its Effect on Adjacent Discs and the Influence of Sagittal Malalignment on its Efficacy: An MRI Study
Proceedings of the NASS 28th Annual Meeting / The Spine Journal 13 (2013) 1S–168S form and the Dallas questionnaire were used to evaluate the physiological and psychological changes of patients. RESULTS: The patients had an average follow-up of 9 months (from 6 to 12 months). A considerable degree of pain relief was obtained in both groups at postoperation and 3-month follow-up (P!0.05). There was no significant difference between the 2 groups in terms of VAS scores at either preoperation or the last follow-up (PO0.05). However, a significant difference of VAS scores was observed at 24-hours postop (P!0.05). In the PKP group, the average anterior vertebral body height was restored by 27.9% (P!0.05) and the average vertebral kyphosis correction was 12.6 (P!0.05). There were no significant differences between the 2 groups in postoperative scores in Health Survey Short Form (standard physical components and standard psychological components), Dallas Pain Questionnaire (activities of daily living, work and play, anxiety and depression, social interests), Barthel index, Mini-Mental State Examination (PO0.05). CONCLUSIONS: Compared to the CT, application of PKP for acute and sub-acute PVCF has advantages such as immediate pain relief, early return to active lifestyle, restoration of the vertebral body height, correction of the kyphosis, and reduction of complication. Although CT could also improve the symptoms after 3 to 6 months treatment, the restoration of vertebral body height and vertebral kyphosis correction is not ideal. FDA DEVICE/DRUG STATUS: PKP balloon kyphoplasty system (Approved for this indication), Bone cement (Approved for this indication). http://dx.doi.org/10.1016/j.spinee.2013.07.247
179. Augmentation of Pedicle Screws with Cement Helps to Prevent Mechanical Failure in Elderly Patients with O5 Levels Instrumentation: A CT Analysis of 688 Pedicle Screws Sinan Kahraman, MD1, Meric Enercan, MD1, Cagatay Ozturk, MD1, Gurkan Gumussuyu, MD1, Tunay Sanli, MA1, Bekir Yavuz Ucar, MD2, Levent Ulusoy, MD1, Azmi Hamzaoglu, MD3, Ahmet Alanay, MD4; 1 Istanbul Spine Center, Istanbul, Turkey; 2Istanbul Spine Center, Diyarbakır, Turkey; 3Istanbul, Turkey; 4Florence Nightingale Hospital, Istanbul, Turkey BACKGROUND CONTEXT: Cement augmentation of pedicle screws (PS) is one of the several measures to prevent screw failure in elderly patients with osteoporosis. PURPOSE: The aim of this study is to analyze the efficacy and complications of cement augmentation in elderly patients with long (O5 levels) instrumentation. STUDY DESIGN/SETTING: Retrospective- level 4 PATIENT SAMPLE: A retrospective analysis of 55 patients who had cement augmented PS was performed. OUTCOME MEASURES: All patients had CT scans taken minimum 2 years after index operation .CTs were analysed to determine PS loosening, cement leakage and fusion rates at augmented levels METHODS: Standard vertebroplasty technique was used for augmentation. Prior to cement injection, mechanical aspiration of the vertebral bodies was done through working cannula to prevent cement emboli. Cement injected was 4cc/lumbar and 2cc/thoracic vertebrae. Screws were placed immediately after cement injection. RESULTS: There were 688 cement augmented PS with a mean f/up of 45 (24-116) months. Average age (40 F, 15M) was 69 (50-85) years. Diagnoses were spinal stenosis in 41, trauma in 1, infection in 5 and revision surgery in 8 patients. Average number of cement-augmented screw/patient was 13 (4-32). Interbody fusion was done in 37 patients (100 levels).There were 10 (1.4%) loose screws in 7 (12.7%) patients. None had pulled out. Screw loosening was at fused levels in all except one with pseudoarthrosis. All loosed screws were at the levels without interbody fusion. One patient
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with pseudoarthrosis had rod breakage and underwent a revision operation. There was no vertebral body fracture at the augmented levels. Extravasation of cement was seen in 7 (12.7%) patients, none in spinal canal. Three (5.4%) patients had asymptomatic pulmonary cement emboli. Three (5.4%) patients had deep wound infection, they were treated successfully with debridement and antibiotic therapy with no need for instrument removal. CONCLUSIONS: Cement augmentation of PS in elderly osteoporotic patients prevents screw pull-out. Screw loosening can be seen with a very low rate and at the levels without interbody fusion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2013.07.248
180. Prophylactic Vertebroplasty of Adjacent Nonfused Segment(s): Its Effect on Adjacent Discs and the Influence of Sagittal Malalignment on its Efficacy: An MRI Study Sinan Kahraman, MD1, Meric Enercan, MD1, Gurkan Gumussuyu, MD1, Cagatay Ozturk, MD1, Tunay Sanli, MA1, Fethi Ceylan, MD2, Levent Ulusoy, MD1, Azmi Hamzaoglu, MD3, Ahmet Alanay, MD4; 1 Istanbul Spine Center, Istanbul, Turkey; 2Van Yuzuncuyil Universitesi, Van, Turkey; 3Istanbul, Turkey; 4Florence Nightingale Hospital, Istanbul, Turkey BACKGROUND CONTEXT: Prophylactic vertebroplasty (PV) has been used to prevent failure of nonfused adjacent segment (ASF) over the longconstruct fusions in osteoporotic pts. However, there is a concern that PV may not be protective against ASF if there is sagittal malalignment after surgery. One other concern is the decreased nutrition of the disc below the augmented level due to cement in the vertebral body causing adjacent segment disc degeneration (ASD) and PJK. PURPOSE: Aim of this study was to analyze the efficacy of PV, its effects on adjacent discs and the effect of residual sagittal plane (SP) misalignment on the success rate of PV STUDY DESIGN/SETTING: Retrospective, Level 4. PATIENT SAMPLE: 48 (35F, 13M) osteoporotic pts. (average age 68 [52-85]) treated with minimum 5 levels’ instrumentation and one or more levels PV with at least 2 years f/up (mean 42,5 [24-70 months]) were included. METHODS: Amount of injected cement was 2cc in upper thoracic and 3cc in lower thoracic spine. All pts had preop and F/up (O2years) MRIs. All discs at PV levels were evaluated in terms of disc degeneration by using Phirmann classification. SP radiography measurements were done to classify postop and f/up SP alignment according to Schwab sagittal modifiers. PJK was determined as the Cobb measurement between the UIV and 2 levels above. All adjacent segments were analyzed to determine ASF. RESULTS: Av instrumentation level was 7,35 (5-16). Average level of PV was 1,25 (1-3). PV was performed at upper thoracic spine (T2-5) in 3 and lower thoracic spine in 45 pts. 60% of pts had perfect SP alignment while 40% had abnormal SP alignment at f/up acc. to Schwab sagittal modifiers. PJK was observed in 10% of pts. ASD below the PV level was observed in 20% of pts. None of the patients had adjacent segment collapse/fracture. There was no correlation between the sagittal misalignment and adjacent segment degeneration, PJK (P50.476) or ASF (P50.282). CONCLUSIONS: PV is effective to prevent adjacent segment failure. Adjacent segment disc degeneration after PV below the PV level is comparable to adjacent segment disc degeneration incidence after long fusions with no PV. Less than optimal sagittal alignment has no negative effect on efficacy of PV.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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Proceedings of the NASS 28th Annual Meeting / The Spine Journal 13 (2013) 1S–168S
FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2013.07.249
Saturday, October 12, 2013 10:00 – 11:00 AM Concurrent Session: Motion Preservation
outcomes that were at least equivalent to ACDF. At 5 years, patients who received the PCM device had a statistically higher mean reduction from baseline in NDI score and a statistically higher rate of NDI success. NDI measures were either stable or improved for PCM at 3, 4, and 5 years, whereas the control group patients were either stable or slightly degraded. Neurological success and rate of secondary surgeries were similar between groups. Overall success favored the PCM group, but rates were not statistically different. FDA DEVICE/DRUG STATUS: PCM Cervical DiscÒ (Approved for this indication) http://dx.doi.org/10.1016/j.spinee.2013.07.251
181. A Prospective, Randomized Clinical Investigation of the PCM Cervical Disc: Five-Year Results from the US IDE Study Frank M. Phillips, MD1, Fred Geisler, MD, PhD2, Christopher D. Chaput, MD3, John G. DeVine, MD4, Kye Gilder, PhD5, Christopher J. Reah, PhD5, Kelli Howell5, Paul C. McAfee, MD, MBA6; 1Midwest Orthopaedics at Rush, Chicago, IL, US; 2Chicago, IL, US, US; 3Scott & White Hospital, Temple, TX, US; 4Eisenhower Army Medical Center, Fort Gordon, GA, US; 5 NuVasive, San Diego, CA, US; 6Orthopaedic Associates of Towson, Towson, MD, US BACKGROUND CONTEXT: Recently, results have been reported following the use of several cervical disc arthroplasty devices as an alternative to fusion after anterior cervical discectomy in the treatment of symptomatic cervical spondylosis. The PCM Cervical DiscÒ is a newly FDA-approved non-constrained device. PURPOSE: This is the first presentation of long-term (5-year) results from the US FDA IDE clinical trial of the PCM Cervical Disc versus anterior cervical discectomy and fusion (ACDF) with allograft and plate. STUDY DESIGN/SETTING: Prospective, randomized, multicenter, IRBapproved IDE clinical trial evaluating longitudinal outcomes over 5 years comparatively between arthroplasty and fusion groups. PATIENT SAMPLE: Patients 18-65 years of age with degenerative disc disease at one level between C3 and T1 with neurologic symptoms unresponsive to conservative care were included. A total of 404 patients were treated (214 PCM, 190 ACDF). The patient sample at 5 years included 160 patient in the PCM group and 124 in the ACDF group. OUTCOME MEASURES: Outcomes measures included neck disability index (NDI), neurological success (a motor, sensory, reflex composite), overall success (composite primary endpoint), flexion-extension range of motion (ROM), and rate of secondary surgeries at the operative level (revisions, reoperations, removals, and supplemental fixation). METHODS: NDI success defined as a minimum 20% improvement over baseline. Neurological success defined as maintenance or improvement in neurological status over baseline. Where appropriate, measures were tested for significant change from baseline to the 5-year postoperative follow-up visit, as well as differences between arthroplasty and fusion groups. RESULTS: At 5 years, the mean NDI score was 20.4 in the PCM group compared to 28.5 in the ACDF group (p50.001). Mean reduction in NDI score from baseline was 34.4 in the PCM group compared to 26.8 in the ACD group (p50.003). NDI success was achieved in 84.7% (133/ 157) of the PCM patients compared to 73.6% (92/125) in the ACDF patients (p50.025). Neurological success was achieved in 92.1% (140/152) of the PCM group and 88.2% (105/119) of the ACDF group (p50.305). ROM at the index level averaged 5.3 (range 0-16.1 ) for the PCM group and 0.5 (range 0-4.1 ) for the controls. In both groups, adjacent level ROM was generally consistent with the 2-, 3- and 4-year results. Overall success was achieved in 66.9% (107/160) of the PCM patients and 57.3% (71/124) of the ACDF patients (p50.108). Of the treated patients, secondary surgeries at the operative level (only reoperations and removals were observed) have been performed on 7.9% (17/214) of the PCM patients and on 7.4% (14/190) of the control patients (p50.854). CONCLUSIONS: This randomized, prospective FDA IDE study found that the treatment of symptomatic single-level cervical spondylosis with the PCM device maintained motion and continued to achieve clinical
182. Five-Year Follow-Up of a Prospective, Randomized FDA IDE Trial Comparing Two Lumbar Total Disc Replacements: Clinical Outcome and Serum Ion Level Analysis for a Metal-on-Metal Device Richard D. Guyer, MD1, Kenneth A. Pettine, MD2, Domagoj Coric, MD3, Donna D. Ohnmeiss, PhD4; 1Texas Back Institute, Plano, TX, US; 2Rocky Mountain Associates in Orthopedic Medicine, Loveland, CO, US; 3 Carolina Neurosurgery & Spine Associates, Charlotte, NC, US; 4Texas Back Institute Research Foundation, Plano, TX, US BACKGROUND CONTEXT: Results at 24-month follow-up in this prospective, randomized FDA IDE trial directly comparing two lumbar total disc replacements (TDRs), found that both treatment groups improved significantly, with no significant differences when comparing groups. One of the devices was a metal-on-metal implant. PURPOSE: The purpose of this study was to compare the clinical outcomes of the two TDRs at 5-year follow-up and secondly, report the 4-year results analyzing serum ion levels in a subgroup of patients. STUDY DESIGN/SETTING: This was a prospective randomized, controlled multicenter trial. PATIENT SAMPLE: The study included 204 patients receiving the Kineflex-L (Investigational group; Spinal Motion) and 190 randomized to Charite (Control group; DePuy). Blood samples were evaluated for serum ion levels of cobalt and chromium in 32 patients in the Investigational group, with 48-month follow-up available for 19 of these patients. OUTCOME MEASURES: Clinical outcome measures included the Oswestry Disability Index (ODI), Visual Analog Scales (VAS) assessing pain, range of motion (ROM) measured from flexion/extension radiographs, and re-operations. To evaluated wear, serum ion levels were evaluated for cobalt and chromium in a subset of patients. METHODS: Five-year follow-up rates were 66.0% in the Investigational group and 70.9% in the Control group. Cobalt and chromium serum ion levels were compared to the Medicines and Health care Products Regulatory Agency (MHRA) value determined to merit following total hip replacement patients more closely for potential wear-related problems. RESULTS: Mean preoperative ODI scores were approximately 60 in both groups, improving significantly (p!0.01) to 37.4 and 36.7 in the two groups. Values remained significantly improved in both groups at 5-year follow-up with values of 21.8 and 20.6. VAS pain scores followed a similar pattern and were also significantly improved throughout the study (p! 0.01). In the Investigation group, preoperative ROM was 6.2 degrees and was significantly improved at 5 year follow-up to 7.6 degrees (p!0.01). In the Control group, preoperative ROM was 6.7 degrees and the mean at 5 years was 7.0 degrees (pO0.25). Approximately 11% of both groups underwent re-operation or revision surgery by 5-year follow-up. Results of serum ion level evaluation in the Investigational group found the greatest mean value at any point during follow-up was 1.24 lg/L for cobalt, occurring at 12 months and 0.77 lg/L for chromium, occurring at 24 months. These values are less than 20% of the minimum value of 7.0 lg/L recommended by the MHRA to merit following total hip replacement patients more closely for potential wear-related problems. By 48 months, values of 0.49 lg/L for cobalt and 0.57 lg/L for chromium were less than 10% of the recommended monitoring threshold.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
179. Augmentation of Pedicle Screws with Cement Helps to Prevent Mechanical Failure in Elderly Patients with O5 Levels Instrumentation: A CT Analysis of 688 Pedicle Screws Sinan Kahraman, MD1, Meric Enercan, MD1, Cagatay Ozturk, MD1, Gurkan Gumussuyu, MD1, Tunay Sanli, MA1, Bekir Yavuz Ucar, MD2, Levent Ulusoy, MD1, Azmi Hamzaoglu, MD3, Ahmet Alanay, MD4; 1 Istanbul Spine Center, Istanbul, Turkey; 2Istanbul Spine Center, Diyarbakır, Turkey; 3Istanbul, Turkey; 4Florence Nightingale Hospital, Istanbul, Turkey BACKGROUND CONTEXT: Cement augmentation of pedicle screws (PS) is one of the several measures to prevent screw failure in elderly patients with osteoporosis. PURPOSE: The aim of this study is to analyze the efficacy and complications of cement augmentation in elderly patients with long (O5 levels) instrumentation. STUDY DESIGN/SETTING: Retrospective- level 4 PATIENT SAMPLE: A retrospective analysis of 55 patients who had cement augmented PS was performed. OUTCOME MEASURES: All patients had CT scans taken minimum 2 years after index operation .CTs were analysed to determine PS loosening, cement leakage and fusion rates at augmented levels METHODS: Standard vertebroplasty technique was used for augmentation. Prior to cement injection, mechanical aspiration of the vertebral bodies was done through working cannula to prevent cement emboli. Cement injected was 4cc/lumbar and 2cc/thoracic vertebrae. Screws were placed immediately after cement injection. RESULTS: There were 688 cement augmented PS with a mean f/up of 45 (24-116) months. Average age (40 F, 15M) was 69 (50-85) years. Diagnoses were spinal stenosis in 41, trauma in 1, infection in 5 and revision surgery in 8 patients. Average number of cement-augmented screw/patient was 13 (4-32). Interbody fusion was done in 37 patients (100 levels).There were 10 (1.4%) loose screws in 7 (12.7%) patients. None had pulled out. Screw loosening was at fused levels in all except one with pseudoarthrosis. All loosed screws were at the levels without interbody fusion. One patient
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with pseudoarthrosis had rod breakage and underwent a revision operation. There was no vertebral body fracture at the augmented levels. Extravasation of cement was seen in 7 (12.7%) patients, none in spinal canal. Three (5.4%) patients had asymptomatic pulmonary cement emboli. Three (5.4%) patients had deep wound infection, they were treated successfully with debridement and antibiotic therapy with no need for instrument removal. CONCLUSIONS: Cement augmentation of PS in elderly osteoporotic patients prevents screw pull-out. Screw loosening can be seen with a very low rate and at the levels without interbody fusion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2013.07.248
180. Prophylactic Vertebroplasty of Adjacent Nonfused Segment(s): Its Effect on Adjacent Discs and the Influence of Sagittal Malalignment on its Efficacy: An MRI Study Sinan Kahraman, MD1, Meric Enercan, MD1, Gurkan Gumussuyu, MD1, Cagatay Ozturk, MD1, Tunay Sanli, MA1, Fethi Ceylan, MD2, Levent Ulusoy, MD1, Azmi Hamzaoglu, MD3, Ahmet Alanay, MD4; 1 Istanbul Spine Center, Istanbul, Turkey; 2Van Yuzuncuyil Universitesi, Van, Turkey; 3Istanbul, Turkey; 4Florence Nightingale Hospital, Istanbul, Turkey BACKGROUND CONTEXT: Prophylactic vertebroplasty (PV) has been used to prevent failure of nonfused adjacent segment (ASF) over the longconstruct fusions in osteoporotic pts. However, there is a concern that PV may not be protective against ASF if there is sagittal malalignment after surgery. One other concern is the decreased nutrition of the disc below the augmented level due to cement in the vertebral body causing adjacent segment disc degeneration (ASD) and PJK. PURPOSE: Aim of this study was to analyze the efficacy of PV, its effects on adjacent discs and the effect of residual sagittal plane (SP) misalignment on the success rate of PV STUDY DESIGN/SETTING: Retrospective, Level 4. PATIENT SAMPLE: 48 (35F, 13M) osteoporotic pts. (average age 68 [52-85]) treated with minimum 5 levels’ instrumentation and one or more levels PV with at least 2 years f/up (mean 42,5 [24-70 months]) were included. METHODS: Amount of injected cement was 2cc in upper thoracic and 3cc in lower thoracic spine. All pts had preop and F/up (O2years) MRIs. All discs at PV levels were evaluated in terms of disc degeneration by using Phirmann classification. SP radiography measurements were done to classify postop and f/up SP alignment according to Schwab sagittal modifiers. PJK was determined as the Cobb measurement between the UIV and 2 levels above. All adjacent segments were analyzed to determine ASF. RESULTS: Av instrumentation level was 7,35 (5-16). Average level of PV was 1,25 (1-3). PV was performed at upper thoracic spine (T2-5) in 3 and lower thoracic spine in 45 pts. 60% of pts had perfect SP alignment while 40% had abnormal SP alignment at f/up acc. to Schwab sagittal modifiers. PJK was observed in 10% of pts. ASD below the PV level was observed in 20% of pts. None of the patients had adjacent segment collapse/fracture. There was no correlation between the sagittal misalignment and adjacent segment degeneration, PJK (P50.476) or ASF (P50.282). CONCLUSIONS: PV is effective to prevent adjacent segment failure. Adjacent segment disc degeneration after PV below the PV level is comparable to adjacent segment disc degeneration incidence after long fusions with no PV. Less than optimal sagittal alignment has no negative effect on efficacy of PV.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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Proceedings of the NASS 28th Annual Meeting / The Spine Journal 13 (2013) 1S–168S
FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2013.07.249
Saturday, October 12, 2013 10:00 – 11:00 AM Concurrent Session: Motion Preservation
outcomes that were at least equivalent to ACDF. At 5 years, patients who received the PCM device had a statistically higher mean reduction from baseline in NDI score and a statistically higher rate of NDI success. NDI measures were either stable or improved for PCM at 3, 4, and 5 years, whereas the control group patients were either stable or slightly degraded. Neurological success and rate of secondary surgeries were similar between groups. Overall success favored the PCM group, but rates were not statistically different. FDA DEVICE/DRUG STATUS: PCM Cervical DiscÒ (Approved for this indication) http://dx.doi.org/10.1016/j.spinee.2013.07.251
181. A Prospective, Randomized Clinical Investigation of the PCM Cervical Disc: Five-Year Results from the US IDE Study Frank M. Phillips, MD1, Fred Geisler, MD, PhD2, Christopher D. Chaput, MD3, John G. DeVine, MD4, Kye Gilder, PhD5, Christopher J. Reah, PhD5, Kelli Howell5, Paul C. McAfee, MD, MBA6; 1Midwest Orthopaedics at Rush, Chicago, IL, US; 2Chicago, IL, US, US; 3Scott & White Hospital, Temple, TX, US; 4Eisenhower Army Medical Center, Fort Gordon, GA, US; 5 NuVasive, San Diego, CA, US; 6Orthopaedic Associates of Towson, Towson, MD, US BACKGROUND CONTEXT: Recently, results have been reported following the use of several cervical disc arthroplasty devices as an alternative to fusion after anterior cervical discectomy in the treatment of symptomatic cervical spondylosis. The PCM Cervical DiscÒ is a newly FDA-approved non-constrained device. PURPOSE: This is the first presentation of long-term (5-year) results from the US FDA IDE clinical trial of the PCM Cervical Disc versus anterior cervical discectomy and fusion (ACDF) with allograft and plate. STUDY DESIGN/SETTING: Prospective, randomized, multicenter, IRBapproved IDE clinical trial evaluating longitudinal outcomes over 5 years comparatively between arthroplasty and fusion groups. PATIENT SAMPLE: Patients 18-65 years of age with degenerative disc disease at one level between C3 and T1 with neurologic symptoms unresponsive to conservative care were included. A total of 404 patients were treated (214 PCM, 190 ACDF). The patient sample at 5 years included 160 patient in the PCM group and 124 in the ACDF group. OUTCOME MEASURES: Outcomes measures included neck disability index (NDI), neurological success (a motor, sensory, reflex composite), overall success (composite primary endpoint), flexion-extension range of motion (ROM), and rate of secondary surgeries at the operative level (revisions, reoperations, removals, and supplemental fixation). METHODS: NDI success defined as a minimum 20% improvement over baseline. Neurological success defined as maintenance or improvement in neurological status over baseline. Where appropriate, measures were tested for significant change from baseline to the 5-year postoperative follow-up visit, as well as differences between arthroplasty and fusion groups. RESULTS: At 5 years, the mean NDI score was 20.4 in the PCM group compared to 28.5 in the ACDF group (p50.001). Mean reduction in NDI score from baseline was 34.4 in the PCM group compared to 26.8 in the ACD group (p50.003). NDI success was achieved in 84.7% (133/ 157) of the PCM patients compared to 73.6% (92/125) in the ACDF patients (p50.025). Neurological success was achieved in 92.1% (140/152) of the PCM group and 88.2% (105/119) of the ACDF group (p50.305). ROM at the index level averaged 5.3 (range 0-16.1 ) for the PCM group and 0.5 (range 0-4.1 ) for the controls. In both groups, adjacent level ROM was generally consistent with the 2-, 3- and 4-year results. Overall success was achieved in 66.9% (107/160) of the PCM patients and 57.3% (71/124) of the ACDF patients (p50.108). Of the treated patients, secondary surgeries at the operative level (only reoperations and removals were observed) have been performed on 7.9% (17/214) of the PCM patients and on 7.4% (14/190) of the control patients (p50.854). CONCLUSIONS: This randomized, prospective FDA IDE study found that the treatment of symptomatic single-level cervical spondylosis with the PCM device maintained motion and continued to achieve clinical
182. Five-Year Follow-Up of a Prospective, Randomized FDA IDE Trial Comparing Two Lumbar Total Disc Replacements: Clinical Outcome and Serum Ion Level Analysis for a Metal-on-Metal Device Richard D. Guyer, MD1, Kenneth A. Pettine, MD2, Domagoj Coric, MD3, Donna D. Ohnmeiss, PhD4; 1Texas Back Institute, Plano, TX, US; 2Rocky Mountain Associates in Orthopedic Medicine, Loveland, CO, US; 3 Carolina Neurosurgery & Spine Associates, Charlotte, NC, US; 4Texas Back Institute Research Foundation, Plano, TX, US BACKGROUND CONTEXT: Results at 24-month follow-up in this prospective, randomized FDA IDE trial directly comparing two lumbar total disc replacements (TDRs), found that both treatment groups improved significantly, with no significant differences when comparing groups. One of the devices was a metal-on-metal implant. PURPOSE: The purpose of this study was to compare the clinical outcomes of the two TDRs at 5-year follow-up and secondly, report the 4-year results analyzing serum ion levels in a subgroup of patients. STUDY DESIGN/SETTING: This was a prospective randomized, controlled multicenter trial. PATIENT SAMPLE: The study included 204 patients receiving the Kineflex-L (Investigational group; Spinal Motion) and 190 randomized to Charite (Control group; DePuy). Blood samples were evaluated for serum ion levels of cobalt and chromium in 32 patients in the Investigational group, with 48-month follow-up available for 19 of these patients. OUTCOME MEASURES: Clinical outcome measures included the Oswestry Disability Index (ODI), Visual Analog Scales (VAS) assessing pain, range of motion (ROM) measured from flexion/extension radiographs, and re-operations. To evaluated wear, serum ion levels were evaluated for cobalt and chromium in a subset of patients. METHODS: Five-year follow-up rates were 66.0% in the Investigational group and 70.9% in the Control group. Cobalt and chromium serum ion levels were compared to the Medicines and Health care Products Regulatory Agency (MHRA) value determined to merit following total hip replacement patients more closely for potential wear-related problems. RESULTS: Mean preoperative ODI scores were approximately 60 in both groups, improving significantly (p!0.01) to 37.4 and 36.7 in the two groups. Values remained significantly improved in both groups at 5-year follow-up with values of 21.8 and 20.6. VAS pain scores followed a similar pattern and were also significantly improved throughout the study (p! 0.01). In the Investigation group, preoperative ROM was 6.2 degrees and was significantly improved at 5 year follow-up to 7.6 degrees (p!0.01). In the Control group, preoperative ROM was 6.7 degrees and the mean at 5 years was 7.0 degrees (pO0.25). Approximately 11% of both groups underwent re-operation or revision surgery by 5-year follow-up. Results of serum ion level evaluation in the Investigational group found the greatest mean value at any point during follow-up was 1.24 lg/L for cobalt, occurring at 12 months and 0.77 lg/L for chromium, occurring at 24 months. These values are less than 20% of the minimum value of 7.0 lg/L recommended by the MHRA to merit following total hip replacement patients more closely for potential wear-related problems. By 48 months, values of 0.49 lg/L for cobalt and 0.57 lg/L for chromium were less than 10% of the recommended monitoring threshold.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.