- Email: [email protected]
Thursday, September 27, 2018 3:35 PM–5:05 PM Section on Motion Technology Abstract Presentations
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The Spine Journal 18 (2018) S50 S69
upper adjacent level 68% and 61% of PCNP group and RP, respectively, showed no degeneration at 5 years. For lower adjacent level 56% and 60% of PCNP group and RP, respectively, showed no degeneration at 5 years. For PCNP group 2 patients experiences 3 complications while 34 occurred for 28 patients of the RP. Only 1 and 4 patients had revision surgery for device removal or repositioning in the PCNP and RP group, respectively. The two groups showed equivalent outcomes regarding professional benefit and medication consumption. Overall patient satisfaction toward surgery was similar in both groups at 5 years (91% and 94%). CONCLUSIONS: Patients with preoperative predominant chronic neck pain had similar patient-reported clinical and radiological outcomes with better improvement for VAS neck pain up to 5 years after surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.402
138. Inpatient cost and length of stay for cervical disc arthroplasty and anterior cervical discectomy and fusion: a cohort-matched comparison Gregory J. Kirchner, MPHa, Alexander M. Lieber, BAa, Yehuda E. Kerbel, MDb, Venkat Kavuri, MDc, Amrit Khalsa, MDd; a Drexel University College of Medicine, Philadelphia, PA, USA; b Drexel University College of Medicine, Department of Orthopaedics, Philadelphia, PA, USA; c Philadelphia, PA, USA; d Hahnemann/Drexel Department of Orthopaedic Surgery, Philadelphia, PA, USA BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is the most common surgical treatment for cervical disc pathology. However, recent evidence has demonstrated superior outcomes with cervical disc arthroplasty (CDA). PURPOSE: This study aims to compare inpatient cost and length of stay (LOS) between cervical disc arthroplasty and anterior cervical discectomy and fusion. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 676 patients were analyzed (338 ACDF and 338 CDA). The average patient ages for ACDF and CDA were 49.15 years and 49.11 years, respectively (p=.957). Only elective hospital admissions were included in this sample. Patients in the ACDF group were limited to those with one to two level fusions. OUTCOME MEASURES: This study compared the ACDF and CDA cohorts on high-end hospital charges and prolonged inpatient length of stay. METHODS: This study screened over 35 million hospital discharges in the United States from 2010 to 2014 using the National Inpatient Sample and the Nationwide Inpatient Sample. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 75,377 patients who underwent ACDF of two or three vertebrae (ICD 81.02 and 81.62), and 387 patients who underwent CDA (ICD 84.62). The ACDF and CDA groups were statistically matched based on age, year of procedure, sex, indication for surgery, race, hospital type, and comorbidities. Mean hospital charges and LOS for each cohort were calculated and compared using the Kruskal Wallis H test. Univariate and multivariate logistic regression were used to compare high-end cost and prolonged LOS between the cohorts, defined as patients with LOS and total hospital charges greater than the 75th percentile of the respective means. RESULTS: We matched 338 (87.34%) CDA patients with patients who underwent ACDF. The average LOS was greater for CDA (x̅ =1.56, SD=0.946) compared to ACDF (x̅ =1.43, SD=1.12; p=.001). Additionally, the average inpatient hospital charges for CDA were $21,320 (SD=10,854) compared to $16,123 (SD=8,499) for ACDF (p<.001). A prolonged LOS occurred in 39.1% of patients in the CDA group compared to 27.5% of the ACDF group (p=.002). Similarly, 34.9% of patients in the CDA group had high-end hospital charges compared to 14.2% of patients in the ACDF group (p<.001). Multivariate analysis demonstrated that patients who underwent ACDF
were significantly less likely to have a prolonged LOS compared to the CDA group (OR=0.678, 95% CI=0.469–0.980). Additionally, multivariate analysis revealed that patients in the ACDF group were a third as likely to have a high-end hospital charge as the CDA group (OR=0.391, 95% CI=0.256–0.599). Patients who underwent ACDF in the southern region of the United States were nearly four-times more likely to have a prolonged LOS than patients who underwent CDA in the same region (OR=3.745, 95% CI=1.450–9.672). Furthermore, patients who underwent ACDF at urban non-teaching hospitals were found to have lesser likelihood of both prolonged LOS (OR=0.588, 95% CI=0.366–0.946) and high-end hospital charges (OR=0.288, 95% CI=0.163–0.508) than patients in the CDA cohort. CONCLUSIONS: Patients who underwent ACDF had significantly lower LOS and hospital charges than a statistically matched CDA cohort. This conclusion directly contradicts recent findings in the literature, although this study is the first to use a large cohort-matched analysis. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.403
139. Artificial disc replacement adjacent to a multilevel fusion in the cervical spine: a biomechanical study Dale Segal, MDa, Zachary J. Grabel, MDa, Jacob M. Wilson, MDb, Andrew H. Milby, MDc, Weilong J. Shi, MDd, William C. Hutton, MDe, John M. Rhee, MDe; a Atlanta, GA, USA; b Emory Orthopedics, Atlanta, GA, USA; c University of Pennsylvania, Philadelphia, PA, USA; d Emory Orthopaedics, Duluth, GA, USA; e Emory University, Atlanta, GA, USA BACKGROUND CONTEXT: Cervical total disc replacement (TDR) has emerged as a motion-preserving alternative to anterior cervical discectomy fusion. Biomechanical studies have demonstrated that the TDR preserves motion at the diseased segment and minimizes motion and stress at adjacent segments compared to fusion. There has been growing interest in performing a TDR adjacent to a cervical fusion. The kinematics of a cervical TDR adjacent to a multilevel fusion construct (>2 levels) has not been investigated. PURPOSE: The purpose of this study was to evaluate the motion of a cervical total disc replacement after fusing adjacent cervical segments both caudal and cranial to the implant. OUTCOME MEASURES: The primary outcome measure was the segmental flexion-extension range of motion at the level of a cervical total disc repalcement. The secondary outcome measures were the overall cervical range of motion and the segemental motion of the remaining cervical segments. METHODS: Seven fresh-frozen human cadaveric cervical spine specimens from C1-T1 were used (average age 56.2±7.3 years). A C6-7 TDR was tested adjacent to a C5-6, C4-6 and C3-6 fusion. A C2-3 TDR was tested adjacent to a C3-4, C3-5 and C3-6 fusion. The protocol consisted of taking lateral radiographs of each construct at maximal angular displacement in flexion and extension. Cobb angles were measured on the digital radiographs to determine flexion-extension range of motion. RESULTS: The segmental ROM of the C6-7 TDR in the unfused spine was 11.3±1.9°. After performing a three-level fusion (C3-6) the segmental motion of the C6-7 TDR increased to 12.9±1.3°(p=.33). The difference between the motion of the C6-7 TDR and the C6-7 native segment caudal to a three-level fusion was not statistically significant; 12.9±1.3° versus 11.3±1.9°, respectively (p=.30).The segmental ROM of the C2-3 TDR in the unfused spine was 5.0 ±1.1. After performing a three-level fusion (C36), the C2-3 TDR segmental motion was 6.1±1.3° (p=.09). The difference in motion of the TDR cranial to a three-level fusion and the native disc cranial to a three-level fusion was not statistically significant; 6.1± 1.3° versus 6.4± 0.8°, respectively (p=.15). CONCLUSIONS: The TDR had similar flexion extension motion to the native segment when instrumented either caudal or cranial to the single, two and three level fusions. The TDR had a trend toward increased motion as additional fusion levels were added adjacent to the implant. Biomechanically, performing a TDR adjacent to a long fusion construct did not
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.
The Spine Journal 18 (2018) S50 S69
upper adjacent level 68% and 61% of PCNP group and RP, respectively, showed no degeneration at 5 years. For lower adjacent level 56% and 60% of PCNP group and RP, respectively, showed no degeneration at 5 years. For PCNP group 2 patients experiences 3 complications while 34 occurred for 28 patients of the RP. Only 1 and 4 patients had revision surgery for device removal or repositioning in the PCNP and RP group, respectively. The two groups showed equivalent outcomes regarding professional benefit and medication consumption. Overall patient satisfaction toward surgery was similar in both groups at 5 years (91% and 94%). CONCLUSIONS: Patients with preoperative predominant chronic neck pain had similar patient-reported clinical and radiological outcomes with better improvement for VAS neck pain up to 5 years after surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.402
138. Inpatient cost and length of stay for cervical disc arthroplasty and anterior cervical discectomy and fusion: a cohort-matched comparison Gregory J. Kirchner, MPHa, Alexander M. Lieber, BAa, Yehuda E. Kerbel, MDb, Venkat Kavuri, MDc, Amrit Khalsa, MDd; a Drexel University College of Medicine, Philadelphia, PA, USA; b Drexel University College of Medicine, Department of Orthopaedics, Philadelphia, PA, USA; c Philadelphia, PA, USA; d Hahnemann/Drexel Department of Orthopaedic Surgery, Philadelphia, PA, USA BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is the most common surgical treatment for cervical disc pathology. However, recent evidence has demonstrated superior outcomes with cervical disc arthroplasty (CDA). PURPOSE: This study aims to compare inpatient cost and length of stay (LOS) between cervical disc arthroplasty and anterior cervical discectomy and fusion. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 676 patients were analyzed (338 ACDF and 338 CDA). The average patient ages for ACDF and CDA were 49.15 years and 49.11 years, respectively (p=.957). Only elective hospital admissions were included in this sample. Patients in the ACDF group were limited to those with one to two level fusions. OUTCOME MEASURES: This study compared the ACDF and CDA cohorts on high-end hospital charges and prolonged inpatient length of stay. METHODS: This study screened over 35 million hospital discharges in the United States from 2010 to 2014 using the National Inpatient Sample and the Nationwide Inpatient Sample. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 75,377 patients who underwent ACDF of two or three vertebrae (ICD 81.02 and 81.62), and 387 patients who underwent CDA (ICD 84.62). The ACDF and CDA groups were statistically matched based on age, year of procedure, sex, indication for surgery, race, hospital type, and comorbidities. Mean hospital charges and LOS for each cohort were calculated and compared using the Kruskal Wallis H test. Univariate and multivariate logistic regression were used to compare high-end cost and prolonged LOS between the cohorts, defined as patients with LOS and total hospital charges greater than the 75th percentile of the respective means. RESULTS: We matched 338 (87.34%) CDA patients with patients who underwent ACDF. The average LOS was greater for CDA (x̅ =1.56, SD=0.946) compared to ACDF (x̅ =1.43, SD=1.12; p=.001). Additionally, the average inpatient hospital charges for CDA were $21,320 (SD=10,854) compared to $16,123 (SD=8,499) for ACDF (p<.001). A prolonged LOS occurred in 39.1% of patients in the CDA group compared to 27.5% of the ACDF group (p=.002). Similarly, 34.9% of patients in the CDA group had high-end hospital charges compared to 14.2% of patients in the ACDF group (p<.001). Multivariate analysis demonstrated that patients who underwent ACDF
were significantly less likely to have a prolonged LOS compared to the CDA group (OR=0.678, 95% CI=0.469–0.980). Additionally, multivariate analysis revealed that patients in the ACDF group were a third as likely to have a high-end hospital charge as the CDA group (OR=0.391, 95% CI=0.256–0.599). Patients who underwent ACDF in the southern region of the United States were nearly four-times more likely to have a prolonged LOS than patients who underwent CDA in the same region (OR=3.745, 95% CI=1.450–9.672). Furthermore, patients who underwent ACDF at urban non-teaching hospitals were found to have lesser likelihood of both prolonged LOS (OR=0.588, 95% CI=0.366–0.946) and high-end hospital charges (OR=0.288, 95% CI=0.163–0.508) than patients in the CDA cohort. CONCLUSIONS: Patients who underwent ACDF had significantly lower LOS and hospital charges than a statistically matched CDA cohort. This conclusion directly contradicts recent findings in the literature, although this study is the first to use a large cohort-matched analysis. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.403
139. Artificial disc replacement adjacent to a multilevel fusion in the cervical spine: a biomechanical study Dale Segal, MDa, Zachary J. Grabel, MDa, Jacob M. Wilson, MDb, Andrew H. Milby, MDc, Weilong J. Shi, MDd, William C. Hutton, MDe, John M. Rhee, MDe; a Atlanta, GA, USA; b Emory Orthopedics, Atlanta, GA, USA; c University of Pennsylvania, Philadelphia, PA, USA; d Emory Orthopaedics, Duluth, GA, USA; e Emory University, Atlanta, GA, USA BACKGROUND CONTEXT: Cervical total disc replacement (TDR) has emerged as a motion-preserving alternative to anterior cervical discectomy fusion. Biomechanical studies have demonstrated that the TDR preserves motion at the diseased segment and minimizes motion and stress at adjacent segments compared to fusion. There has been growing interest in performing a TDR adjacent to a cervical fusion. The kinematics of a cervical TDR adjacent to a multilevel fusion construct (>2 levels) has not been investigated. PURPOSE: The purpose of this study was to evaluate the motion of a cervical total disc replacement after fusing adjacent cervical segments both caudal and cranial to the implant. OUTCOME MEASURES: The primary outcome measure was the segmental flexion-extension range of motion at the level of a cervical total disc repalcement. The secondary outcome measures were the overall cervical range of motion and the segemental motion of the remaining cervical segments. METHODS: Seven fresh-frozen human cadaveric cervical spine specimens from C1-T1 were used (average age 56.2±7.3 years). A C6-7 TDR was tested adjacent to a C5-6, C4-6 and C3-6 fusion. A C2-3 TDR was tested adjacent to a C3-4, C3-5 and C3-6 fusion. The protocol consisted of taking lateral radiographs of each construct at maximal angular displacement in flexion and extension. Cobb angles were measured on the digital radiographs to determine flexion-extension range of motion. RESULTS: The segmental ROM of the C6-7 TDR in the unfused spine was 11.3±1.9°. After performing a three-level fusion (C3-6) the segmental motion of the C6-7 TDR increased to 12.9±1.3°(p=.33). The difference between the motion of the C6-7 TDR and the C6-7 native segment caudal to a three-level fusion was not statistically significant; 12.9±1.3° versus 11.3±1.9°, respectively (p=.30).The segmental ROM of the C2-3 TDR in the unfused spine was 5.0 ±1.1. After performing a three-level fusion (C36), the C2-3 TDR segmental motion was 6.1±1.3° (p=.09). The difference in motion of the TDR cranial to a three-level fusion and the native disc cranial to a three-level fusion was not statistically significant; 6.1± 1.3° versus 6.4± 0.8°, respectively (p=.15). CONCLUSIONS: The TDR had similar flexion extension motion to the native segment when instrumented either caudal or cranial to the single, two and three level fusions. The TDR had a trend toward increased motion as additional fusion levels were added adjacent to the implant. Biomechanically, performing a TDR adjacent to a long fusion construct did not
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.