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Norimasa Iwasaki - One of the best experts on this subject based on the ideXlab platform.
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postoperative translation of the upper instrumented vertebra in thoracic adolescent idiopathic scoliosis
Journal of Neurosurgery, 2018Co-Authors: Katsuhisa Yamada, Hideki Sudo, Kiyoshi Kaneda, Yasuhiro Shono, Yuichiro Abe, Norimasa IwasakiAbstract:OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented vertebra (UIV) translation from the C7 Plumb Line (C7PL) on the long-term postoperative results of patients with main thoracic (MT) adolescent idiopathic scoliosis (AIS).METHODSTwenty-five patients had been treated surgically for AIS with a Lenke type 1 curve and had been followed up for a mean period of 18.2 years. Radiographic parameters, pulmonary function measurements, and clinical outcomes were compared between the patients (n = 15) with UIV translation < 20 mm and those (n = 10) with UIV translation ≥ 20 mm at the final follow-up. Correlations between UIV translation and radiographic or pulmonary function parameters were analyzed.RESULTSPatients with ≥ 20 mm UIV translation at the final follow-up had a significantly larger preoperative UIV translation than that in the patients with < 20 mm UIV translation at follow-up. The former group also had a significantly lower correction rate of the MT curve, higher...
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Impact of spino-pelvic and global spinal alignment on the risk of osteoporotic vertebral collapse
The Japanese Society for Spine Surgery and Related Research, 2018Co-Authors: Takashi Ohnishi, Akira Iwata, Masahiro Kanayama, Fumihiro Oha, Tomoyuki Hashimoto, Norimasa IwasakiAbstract:Introduction: Numerous studies have reported the risk factors of osteoporotic vertebral collapse. However, whether spino-pelvic and global spinal alignments are associated with the occurrence of osteoporotic vertebral collapse remains unclear. This study aimed to investigate the association between spino-pelvic and global spinal alignments and the occurrence of osteoporotic vertebral collapse. Methods: A total of 46 consecutive patients who underwent a nonoperative treatment for a single-level fresh osteoporotic thoracolumbar vertebral compression fracture (T10 to L3) were retrospectively reviewed. The parameters evaluated were the pelvic incidence, anterior deviation of the C7 Plumb Line, distance between the C7 Plumb Line and the center of the fractured vertebra, and kyphotic wedge angle of the fractured vertebra in a standing whole-spine radiograph at the beginning of the nonoperative treatment. As an outcome measure, the presence or absence of osteoporotic vertebral collapse was radiographically evaluated at the final follow-up. Multiple logistic regression analysis was used to determine significant risk factors of osteoporotic vertebral collapse. Results: The mean values for each parameter were as follows: pelvic incidence, 58.0 degrees; anterior deviation of the C7 Plumb Line, 3.0 cm; distance between the C7 Plumb Line and the center of the fractured vertebra, 5.7 cm; and kyphotic wedge angle of the fractured vertebra, 14.6 degrees. Multiple logistic regression analysis revealed that the distance between the C7 Plumb Line and center of the fractured vertebra was a significant risk factor of osteoporotic vertebral collapse (p = 0.012; odds ratio, 1.025). The anterior deviation of the C7 Plumb Line (p = 0.214), pelvic incidence (p = 0.728), and kyphotic wedge angle of the fractured vertebra (p = 0.07) did not affect the occurrence of osteoporotic vertebral collapse. Conclusions: A large distance between the C7 Plumb Line and center of the fractured vertebra was a significant risk factor of osteoporotic vertebral collapse. The distance approximately represents that of between gravity center of trunk cranial to the fractured vertebra and the fractured vertebra. Accordingly, the large distance may cause larger flexion moment to the fractured site, leading to stress concentration that results in insufficient bone healing
Keith H. Bridwell - One of the best experts on this subject based on the ideXlab platform.
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long adult deformity fusions to l5 and the sacrum a matched cohort analysis
Spine, 2004Co-Authors: Charles C Edwards, Anthony Rinella, Annette Berra, Alpesh A Patel, Keith H. Bridwell, Lawrence G. LenkeAbstract:STUDY DESIGN: A matched cohort analysis of long adult deformity fusions according to distal fusion level (L5 vs. S1). OBJECTIVE.: To compare the results of long adult deformity fusions to either L5 or the sacrum in the presence of a "healthy" 5-1 disc using a matched cohort analysis. SUMMARY OF BACKGROUND DATA: For adult spinal deformity, the decision often arises whether to terminate a long fusion at L5 or the sacrum. The decision is especially challenging in the presence of a "healthy" (Grade 0 to 1 degeneration) 5-1 disc. MATERIALS AND METHODS: A total of 95 adult deformity patients that underwent fusion from the thoracic spine to either L5 or the sacrum were sorted according to five preoperative criteria: 5-1 disc status, patient age, smoking status, number of levels fused, and sagittal balance. Two cohorts (L5, 27 patients; sacrum, 12 patients) were precisely matched according to the five criteria. Patients were evaluated at 2-year minimum follow-up according to radiographic data, complications, and SRS-24 outcomes. RESULTS: Correction of sagittal imbalance was superior for sacrum patients (C7 Plumb Line: L5, 0.9 cm; sacrum, 3.2 cm; P = 0.03). At latest follow-up (L5, 5.2 years; sacrum, 3.7 years), 67% of L5 patients had radiographic evidence of advanced 5-1 disc degeneration and the L5 cohort tended to have inferior sagittal balance (C7 Plumb Line: L5, +4.0 cm; sacrum, +1.2 cm; P = 0.06). The sacrum cohort, however, required more surgical procedures (L5, 1.7; sacrum, 2.8; P = 0.03) and experienced a greater frequency of major complications (L5, 22%; sacrum, 75%; P = 0.02), including nonunion (L5, 4%; sacrum, 42%; P = 0.006) and medical morbidity (L5, 0%; sacrum, 33%; P = 0.001). SRS-24 scores reflected a similar patient assessment of outcome and function for the two cohorts (L5, 89; sacrum, 87). DISCUSSION AND CONCLUSION: At 3 to 5 years' mean follow-up, long adult fusions to the sacrum required more procedures and had a higher frequency of complications than similar fusions to L5. For fusions to L5, subsequent subjacent disc degeneration is common and may be associated with a forward shift in sagittal balance. The ultimate influence of these factors on long-term outcomes remains to be seen.
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pedicle subtraction osteotomy for the treatment of fixed sagittal imbalance
Journal of Bone and Joint Surgery American Volume, 2004Co-Authors: Keith H. Bridwell, Lawrence G. Lenke, Christy Baldus, Stephen J Lewis, Kathy BlankeAbstract:BACKGROUND: Fixed sagittal imbalance (a syndrome in which the patient is only able to stand with the weight-bearing Line in front of the sacrum) has many etiologies. The most commonly reported technique for correction is the Smith-Petersen osteotomy. Few reports on pedicle subtraction procedures (resection of the posterior elements, pedicles, and vertebral body through a posterior approach) are available in the peer-reviewed literature. We are aware of no report involving a substantial number of patients with coexistent scoliosis who underwent pedicle/vertebral body subtraction for the treatment of fixed sagittal imbalance. METHODS: Twenty-seven consecutive patients in whom sagittal imbalance was treated with lumbar pedicle subtraction osteotomy at one institution were analyzed. Radiographic analysis included assessment ofthoracic kyphosis, lumbar lordosis, lordosis through the pedicle subtraction osteotomy site, and the C7 sagittal Plumb Line. Outcomes analysis was performed with use of a before-and-after pain scale, items from the Oswestry questionnaire, and the Scoliosis Research Society (SRS) questionnaire after a minimum duration of follow-up of two years. Complications and radiographic findings were also analyzed for the entire group. RESULTS: Overall, the average increase in lordosis was 34.1° and the average improvement in the sagittal Plumb Line was 13.5 cm. One patient had development of a lumbar pseudarthrosis through the area of pedicle subtraction osteotomy, and six patients had development of a thoracic pseudarthrosis. Two patients had development of increased kyphosis at L5/S1, caudad to the fusion, resulting in some loss of sagittal correction. There were significant improvements in the overall Oswestry score (p < 0.0001) and the pain-scale score (p = 0.0002). Most patients reported improvement in terms of pain and self-image as well as overall satisfaction with the procedure. CONCLUSIONS: Pedicle subtraction osteotomy is a useful procedure for patients with fixed sagittal imbalance. A worse clinical result is associated with increasing patient comorbidities, pseudarthrosis in the thoracic spine, and subsequent breakdown caudad to the fusion.
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Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults.
Spine, 1998Co-Authors: Ravishankar Vedantam, Lawrence G. Lenke, James A. Keeney, Keith H. BridwellAbstract:Study Design. A retrospective examination of the spine radiographs of 88 asymptomatic adolescents was performed to analyze the indices of regional and segmental sagittal spinal alignment in relation to the sagittal vertical axis as determined by the C7 Plumb Line. Objectives. To determine the sagittal spinal alignment in asymptomatic adolescents and to correlate the sagittal vertical axis with the overall sagittal spinal balance and other indices of sagittal spinal alignment. In addition, to compare these results with previously established data for asymptomatic adults. Summary of Background Data. Previous studies of sagittal spinal alignment have included subjects encompassing a wide range of ages. A previous study at the authors' institution established normative data for sagittal spinal alignment in asymptomatic adults. No previous study has reported on the correlation between the sagittal vertical axis and other measurements of sagittal spinal alignment in asymptomatic adolescents. Methods. Measurements obtained from the standing lateral spine radiographs of 88 asymptomatic adolescents (age range, 10-18 years) were collected and analyzed using statistical methods. These data were compared with previously established data for asymptomatic adults. Results. There was a striking similarity in regional thoracic kyphosis and lumbar lordosis between adolescents and adults. Despite having similar regional and segmental sagittal alignments, adolescents had a significantly more negative sagittal vertical axis (mean, −5.6 cm) than adults (mean, −3.2 cm; P = 0.0001). Also, unlike that in adults, the sagittal vertical axis in adolescents was not significantly correlated with the distal segmental lumbar lordosis. The sagittal vertical axis in adolescents was significantly correlated with the level of thoracic kyphosis and the distances from the thoracic apex, lumbar apex, and T12 to the C7 Plumb Line. Sacral inclination, which is a determinant of hip extension and standing pelvic rotation, was correlated with the lumbar apex and the total and segmental lordosis, except at L5-S1. Conclusions. Asymptomatic adolescents tend to stand in greater negative sagittal spinal balance than asymptomatic adults, despite similar regional and segmental alignments in the thoracic and lumbar spine. The role of hip extension, spinopelvic axis rotation, and other sagittal alignment parameters in determining the sagittal vertical axis in adolescents warrants further study.
Lawrence G. Lenke - One of the best experts on this subject based on the ideXlab platform.
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Intraoperative versus postoperative radiographic coronal balance for adult spinal deformity surgery
Spine Deformity, 2021Co-Authors: Alexander Tuchman, Justin Matthew, Nathan Lee, Meghan Cerpa, Ronald A. Lehman, Lawrence G. LenkeAbstract:Background Coronal malalignment in adult spinal deformity (ASD) has a close relationship with patient clinical outcomes. The purpose of this study is to evaluate the relationship between intra- and postoperative coronal radiographic parameters. A novel parameter, the central sacral pelvic Line (CSPL), and its relation to the central sacral vertical Line (CSVL) is explored. CSPL is a measure of spinal alignment referenced to the patient’s pelvis as an intraoperative proxy for CSVL. CSVL is difficult to measure intraoperatively, because a C7-Plumb Line (referenced to gravity) cannot be drawn in the supine position. Methods 47 subjects ≥ 18 years old undergoing a spinal fusion of ≥ 6 levels from 2015 to 2017 were enrolled. The CSPL is defined as the perpendicular Line bisecting the midpoint of the Line that connects the superior aspects of the acetabuli. Two metrics describing coronal alignment were derived from each radiograph: (1) horizontal distance between the C7-Plumb Line and the CSPL at C7 (C7-CSPL) and (2) horizontal distance between the C7-Plumb Line and CSVL (C7-CSVL). Pearson’s correlation and Linear regression analysis was used to study the relationship between the intraoperative C7-CSPL and the postoperative C7-CSVL. Results On average, the intraoperative C7-CSPL distance was 32.1 mm, postoperative C7-CSPL 20.8 mm, and postoperative C7-CSVL 18.9 mm. 15/47 (32%) had intraoperative C7-CSPL measurements > 4 cm, requiring intraoperative correction. Of those 15, 10 patients (67%) still had a postoperative C7-CSVL
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long adult deformity fusions to l5 and the sacrum a matched cohort analysis
Spine, 2004Co-Authors: Charles C Edwards, Anthony Rinella, Annette Berra, Alpesh A Patel, Keith H. Bridwell, Lawrence G. LenkeAbstract:STUDY DESIGN: A matched cohort analysis of long adult deformity fusions according to distal fusion level (L5 vs. S1). OBJECTIVE.: To compare the results of long adult deformity fusions to either L5 or the sacrum in the presence of a "healthy" 5-1 disc using a matched cohort analysis. SUMMARY OF BACKGROUND DATA: For adult spinal deformity, the decision often arises whether to terminate a long fusion at L5 or the sacrum. The decision is especially challenging in the presence of a "healthy" (Grade 0 to 1 degeneration) 5-1 disc. MATERIALS AND METHODS: A total of 95 adult deformity patients that underwent fusion from the thoracic spine to either L5 or the sacrum were sorted according to five preoperative criteria: 5-1 disc status, patient age, smoking status, number of levels fused, and sagittal balance. Two cohorts (L5, 27 patients; sacrum, 12 patients) were precisely matched according to the five criteria. Patients were evaluated at 2-year minimum follow-up according to radiographic data, complications, and SRS-24 outcomes. RESULTS: Correction of sagittal imbalance was superior for sacrum patients (C7 Plumb Line: L5, 0.9 cm; sacrum, 3.2 cm; P = 0.03). At latest follow-up (L5, 5.2 years; sacrum, 3.7 years), 67% of L5 patients had radiographic evidence of advanced 5-1 disc degeneration and the L5 cohort tended to have inferior sagittal balance (C7 Plumb Line: L5, +4.0 cm; sacrum, +1.2 cm; P = 0.06). The sacrum cohort, however, required more surgical procedures (L5, 1.7; sacrum, 2.8; P = 0.03) and experienced a greater frequency of major complications (L5, 22%; sacrum, 75%; P = 0.02), including nonunion (L5, 4%; sacrum, 42%; P = 0.006) and medical morbidity (L5, 0%; sacrum, 33%; P = 0.001). SRS-24 scores reflected a similar patient assessment of outcome and function for the two cohorts (L5, 89; sacrum, 87). DISCUSSION AND CONCLUSION: At 3 to 5 years' mean follow-up, long adult fusions to the sacrum required more procedures and had a higher frequency of complications than similar fusions to L5. For fusions to L5, subsequent subjacent disc degeneration is common and may be associated with a forward shift in sagittal balance. The ultimate influence of these factors on long-term outcomes remains to be seen.
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pedicle subtraction osteotomy for the treatment of fixed sagittal imbalance
Journal of Bone and Joint Surgery American Volume, 2004Co-Authors: Keith H. Bridwell, Lawrence G. Lenke, Christy Baldus, Stephen J Lewis, Kathy BlankeAbstract:BACKGROUND: Fixed sagittal imbalance (a syndrome in which the patient is only able to stand with the weight-bearing Line in front of the sacrum) has many etiologies. The most commonly reported technique for correction is the Smith-Petersen osteotomy. Few reports on pedicle subtraction procedures (resection of the posterior elements, pedicles, and vertebral body through a posterior approach) are available in the peer-reviewed literature. We are aware of no report involving a substantial number of patients with coexistent scoliosis who underwent pedicle/vertebral body subtraction for the treatment of fixed sagittal imbalance. METHODS: Twenty-seven consecutive patients in whom sagittal imbalance was treated with lumbar pedicle subtraction osteotomy at one institution were analyzed. Radiographic analysis included assessment ofthoracic kyphosis, lumbar lordosis, lordosis through the pedicle subtraction osteotomy site, and the C7 sagittal Plumb Line. Outcomes analysis was performed with use of a before-and-after pain scale, items from the Oswestry questionnaire, and the Scoliosis Research Society (SRS) questionnaire after a minimum duration of follow-up of two years. Complications and radiographic findings were also analyzed for the entire group. RESULTS: Overall, the average increase in lordosis was 34.1° and the average improvement in the sagittal Plumb Line was 13.5 cm. One patient had development of a lumbar pseudarthrosis through the area of pedicle subtraction osteotomy, and six patients had development of a thoracic pseudarthrosis. Two patients had development of increased kyphosis at L5/S1, caudad to the fusion, resulting in some loss of sagittal correction. There were significant improvements in the overall Oswestry score (p < 0.0001) and the pain-scale score (p = 0.0002). Most patients reported improvement in terms of pain and self-image as well as overall satisfaction with the procedure. CONCLUSIONS: Pedicle subtraction osteotomy is a useful procedure for patients with fixed sagittal imbalance. A worse clinical result is associated with increasing patient comorbidities, pseudarthrosis in the thoracic spine, and subsequent breakdown caudad to the fusion.
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Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults.
Spine, 1998Co-Authors: Ravishankar Vedantam, Lawrence G. Lenke, James A. Keeney, Keith H. BridwellAbstract:Study Design. A retrospective examination of the spine radiographs of 88 asymptomatic adolescents was performed to analyze the indices of regional and segmental sagittal spinal alignment in relation to the sagittal vertical axis as determined by the C7 Plumb Line. Objectives. To determine the sagittal spinal alignment in asymptomatic adolescents and to correlate the sagittal vertical axis with the overall sagittal spinal balance and other indices of sagittal spinal alignment. In addition, to compare these results with previously established data for asymptomatic adults. Summary of Background Data. Previous studies of sagittal spinal alignment have included subjects encompassing a wide range of ages. A previous study at the authors' institution established normative data for sagittal spinal alignment in asymptomatic adults. No previous study has reported on the correlation between the sagittal vertical axis and other measurements of sagittal spinal alignment in asymptomatic adolescents. Methods. Measurements obtained from the standing lateral spine radiographs of 88 asymptomatic adolescents (age range, 10-18 years) were collected and analyzed using statistical methods. These data were compared with previously established data for asymptomatic adults. Results. There was a striking similarity in regional thoracic kyphosis and lumbar lordosis between adolescents and adults. Despite having similar regional and segmental sagittal alignments, adolescents had a significantly more negative sagittal vertical axis (mean, −5.6 cm) than adults (mean, −3.2 cm; P = 0.0001). Also, unlike that in adults, the sagittal vertical axis in adolescents was not significantly correlated with the distal segmental lumbar lordosis. The sagittal vertical axis in adolescents was significantly correlated with the level of thoracic kyphosis and the distances from the thoracic apex, lumbar apex, and T12 to the C7 Plumb Line. Sacral inclination, which is a determinant of hip extension and standing pelvic rotation, was correlated with the lumbar apex and the total and segmental lordosis, except at L5-S1. Conclusions. Asymptomatic adolescents tend to stand in greater negative sagittal spinal balance than asymptomatic adults, despite similar regional and segmental alignments in the thoracic and lumbar spine. The role of hip extension, spinopelvic axis rotation, and other sagittal alignment parameters in determining the sagittal vertical axis in adolescents warrants further study.
Kathy Blanke - One of the best experts on this subject based on the ideXlab platform.
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COPYRIGHT © 2003 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED Pedicle Subtraction Osteotomy for the Treatment of Fixed Sagittal Imbalance
2016Co-Authors: Christy Baldus, Kathy BlankeAbstract:Background: Fixed sagittal imbalance (a syndrome in which the patient is only able to stand with the weight-bearing Line in front of the sacrum) has many etiologies. The most commonly reported technique for correction is the Smith-Petersen osteotomy. Few reports on pedicle subtraction procedures (resection of the posterior elements, pedicles, and vertebral body through a posterior approach) are available in the peer-reviewed literature. We are aware of no re-port involving a substantial number of patients with coexistent scoliosis who underwent pedicle/vertebral body sub-traction for the treatment of fixed sagittal imbalance. Methods: Twenty-seven consecutive patients in whom sagittal imbalance was treated with lumbar pedicle subtraction osteotomy at one institution were analyzed. Radiographic analysis included assessment of thoracic kyphosis, lumbar lordosis, lordosis through the pedicle subtraction osteotomy site, and the C7 sagittal Plumb Line. Outcomes analysis was performed with use of a before-and-after pain scale, items from the Oswestry questionnaire, and the Scoliosis Research Society (SRS) questionnaire after a minimum duration of follow-up of two years. Complications and radio-graphic findings were also analyzed for the entire group. Results: Overall, the average increase in lordosis was 34.1 ° and the average improvement in the sagittal Plumb Line was 13.5 cm. One patient had development of a lumbar pseudarthrosis through the area of pedicle subtraction os-teotomy, and six patients had development of a thoracic pseudarthrosis. Two patients had development of increase
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pedicle subtraction osteotomy for the treatment of fixed sagittal imbalance
Journal of Bone and Joint Surgery American Volume, 2004Co-Authors: Keith H. Bridwell, Lawrence G. Lenke, Christy Baldus, Stephen J Lewis, Kathy BlankeAbstract:BACKGROUND: Fixed sagittal imbalance (a syndrome in which the patient is only able to stand with the weight-bearing Line in front of the sacrum) has many etiologies. The most commonly reported technique for correction is the Smith-Petersen osteotomy. Few reports on pedicle subtraction procedures (resection of the posterior elements, pedicles, and vertebral body through a posterior approach) are available in the peer-reviewed literature. We are aware of no report involving a substantial number of patients with coexistent scoliosis who underwent pedicle/vertebral body subtraction for the treatment of fixed sagittal imbalance. METHODS: Twenty-seven consecutive patients in whom sagittal imbalance was treated with lumbar pedicle subtraction osteotomy at one institution were analyzed. Radiographic analysis included assessment ofthoracic kyphosis, lumbar lordosis, lordosis through the pedicle subtraction osteotomy site, and the C7 sagittal Plumb Line. Outcomes analysis was performed with use of a before-and-after pain scale, items from the Oswestry questionnaire, and the Scoliosis Research Society (SRS) questionnaire after a minimum duration of follow-up of two years. Complications and radiographic findings were also analyzed for the entire group. RESULTS: Overall, the average increase in lordosis was 34.1° and the average improvement in the sagittal Plumb Line was 13.5 cm. One patient had development of a lumbar pseudarthrosis through the area of pedicle subtraction osteotomy, and six patients had development of a thoracic pseudarthrosis. Two patients had development of increased kyphosis at L5/S1, caudad to the fusion, resulting in some loss of sagittal correction. There were significant improvements in the overall Oswestry score (p < 0.0001) and the pain-scale score (p = 0.0002). Most patients reported improvement in terms of pain and self-image as well as overall satisfaction with the procedure. CONCLUSIONS: Pedicle subtraction osteotomy is a useful procedure for patients with fixed sagittal imbalance. A worse clinical result is associated with increasing patient comorbidities, pseudarthrosis in the thoracic spine, and subsequent breakdown caudad to the fusion.
Gunter Seeber - One of the best experts on this subject based on the ideXlab platform.
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modern determination of vertical deflections using digital zenith cameras
Journal of Surveying Engineering-asce, 2010Co-Authors: Christian Hirt, Beat Burki, Anna Somieski, Gunter SeeberAbstract:At the beginning of the 21st century, a significant technological change took place in geodetic astronomy. In Zurich and Hannover, digital zenith camera systems were developed based on digital imaging sensors (charge-coupled device) that strongly improved the degree of automation, efficiency, and accuracy of the observation of the direction of the Plumb Line and its vertical deflection. This paper describes the instrumental design of the new digital zenith camera systems and gives an overview of the data processing with focus on the models used for astrometric data reduction and tilt correction. Results of frequently repeated observations of vertical deflections and comparison measurements show an accuracy of vertical deflection measurements of better than 0.1 arc sec. Application examples for vertical deflection data from zenith camera observations, such as the high-precision local gravity field determination in engineering projects and gravity field validation are summarized.