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Alexej Barg - One of the best experts on this subject based on the ideXlab platform.
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interaction of loading and ligament injuries in Subtalar Joint instability quantified by 3d weightbearing computed tomography
Journal of Orthopaedic Research, 2021Co-Authors: Arne Burssens, Nicola Krahenbuhl, Charles L Saltzman, Alexej Barg, Amy L Lenz, Kalebb Howell, Chong Zhang, Yantarat SripanichAbstract:Despite decades of research since its first description, Subtalar Joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two-dimensional measurements. Therefore, we used weightbearing CT imaging to quantify three-dimensional displacement associated with Subtalar Joint instability. Three-dimensional models were generated in seven paired cadaver specimens to compute talocalcaneal displacement after different patterns of axial load (85kg) combined with torque in internal and external rotation (10Nm). Sequential imaging was repeated in the Subtalar Joint containing intact ligaments to determine reference displacement. Afterwards the interosseus talo-calcaneal ligament (ITCL) or calcaneofibular ligament (CFL) was sectioned, then the ITCL with CFL and after the ITCL, CFL with the deltoid ligament (DL). The highest translation could be detected in the dorsal direction and the highest rotation occurred in the internaldirection, when external torque was applied to the foot without load. These displacements differed significantly from the condition containing intact ligaments, with a mean difference of 1.6 mm (95% CI, 1.3 to 1.9) for dorsal translation and mean of 12.4° (95% CI, 10.1 to 14.8) for internal rotation. Clinical relevance- Our study provides a novel and non-invasive analysis to quantify Subtalar Joint instability based on three-dimensional WBCT imaging. This approach overcomes former studies using trans-osseous fixation to determine three-dimensional Subtalar Joint displacement and implements an imaging device and software modalities that are readily available. Based on our findings, we recommend applying torque inexternal rotation to the foot to optimize detection of Subtalar Joint instability. This article is protected by copyright. All rights reserved.
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morphologic analysis of the Subtalar Joint using statistical shape modeling
Journal of Orthopaedic Research, 2020Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Charles L Saltzman, Alexej Barg, Amy L Lenz, Rich Lisonbee, Andrew C Peterson, Penny R Atkins, Andrew E AndersonAbstract:Weightbearing computed tomography (WBCT) enables visualization of the foot and ankle as patients stand under load. Clinical measurements of WBCT images are generally limited to two-dimensions, which reduces the ability to quantify complex morphology of individual osseous structures as well as the alignment between two or more bones. The shape and orientation of the healthy/normal Subtalar Joint, in particular, is not well-understood, which makes it very difficult to diagnose Subtalar pathoanatomy. Herein, we employed statistical shape modeling to evaluate three-dimensional (3D) shape variation, coverage, space, and congruency of the Subtalar Joint using WBCT data of 27 asymptomatic healthy individuals. The four most relevant findings were: (A) talar and calcaneal anatomical differences were found regarding the presence of (a) the talar posterior process, (b) calcaneal pitch, and (c) curvature of the calcaneal posterior facet; (B) the talar posterior facet articular surface area was significantly greater than the calcaneal posterior facet articular surface area; (C) the posterior facet varied in Joint space distance, whereas the anteromedial facet was even; and (D) the posterior and anteromedial facet of the Subtalar Joint was consistently congruent. Despite considerable shape variation across the population, the posterior and anteromedial articular facets of the Subtalar Joint were consistently congruent. Results provide a detailed 3D analysis of the Subtalar Joint under a weightbearing condition in a healthy population which can be used for comparisons to pathological patient populations. The described SSM approach also shows promise for clinical evaluation of the Subtalar Joint from 3D surface reconstructions of WBCT images.
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compensatory motion of the Subtalar Joint following tibiotalar arthrodesis an in vivo dual fluoroscopy imaging study
Journal of Bone and Joint Surgery American Volume, 2020Co-Authors: Amy L Lenz, Charles L Saltzman, Alexej Barg, Jennifer A Nichols, Koren E Roach, Bo K Foreman, Andrew E AndersonAbstract:Background Tibiotalar arthrodesis is a common treatment for end-stage tibiotalar osteoarthritis, and is associated with a long-term risk of concomitant Subtalar osteoarthritis. It has been clinically hypothesized that Subtalar osteoarthritis following tibiotalar arthrodesis is the product of compensatory Subtalar Joint hypermobility. However, in vivo measurements of Subtalar Joint motion following tibiotalar arthrodesis have not been quantified. Using dual-fluoroscopy motion capture, we tested the hypothesis that the Subtalar Joint of the limb with a tibiotalar arthrodesis would demonstrate differences in kinematics and increased range of motion compared with the Subtalar Joint of the contralateral, asymptomatic, untreated ankle. Methods Ten asymptomatic patients who had undergone unilateral tibiotalar arthrodesis at a mean (and standard deviation) of 4.0 ± 1.8 years previously were evaluated during overground walking and a double heel-rise task. The evaluation involved markerless tracking with use of dual fluoroscopy integrated with 3-dimensional computed tomography, which allowed for dynamic measurements of Subtalar and tibiotalar dorsiflexion-plantar flexion, inversion-eversion, and internal-external rotation. Range of motion, stance time, swing time, step length, and step width were also measured. Results During the early stance phase of walking, the Subtalar Joint of the limb that had been treated with arthrodesis was plantar flexed (-4.7° ± 3.3°), whereas the Subtalar Joint of the untreated limb was dorsiflexed (4.6° ± 2.2°). Also, during the early stance phase of walking, eversion of the Subtalar Joint of the surgically treated limb (0.2° ± 2.3°) was less than that of the untreated limb (4.5° ± 3.2°). During double heel-rise, the treated limb exhibited increased peak Subtalar plantar flexion (-7.1° ± 4.1°) compared with the untreated limb (0.2° ± 1.8°). Conclusions A significant increase in Subtalar Joint plantar flexion was found to be a primary compensation during overground walking and a double heel-rise activity following tibiotalar arthrodesis. Clinical relevance Significant Subtalar Joint plantar flexion compensations appear to occur following tibiotalar arthrodesis. We found an increase in Subtalar plantar flexion and considered the potential relationship of this finding with the increased rate of Subtalar osteoarthritis that occurs following ankle arthrodesis.
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currently used imaging options cannot accurately predict Subtalar Joint instability
Knee Surgery Sports Traumatology Arthroscopy, 2019Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Maxwell W Weinberg, Nathan P Davidson, Megan K Mills, Charles L Saltzman, Alexej BargAbstract:To give a systematic overview of current diagnostic imaging options and surgical treatment for chronic Subtalar Joint instability. A systematic literature search across the following sources was performed: PubMed, ScienceDirect, and SpringerLink. Twenty-three imaging studies and 19 outcome studies were included. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2) tool was used to assess the methodologic quality of the imaging articles, while the modified Coleman Score was used to assess the methodologic quality of the outcome studies. Conventional radiographs were most frequently used to assess chronic Subtalar Joint instability. Talar tilt, anterior talar translation, and Subtalar tilt were the three most commonly used measurement methods. Surgery often included calcaneofibular ligament reconstruction. Current imaging options do not reliably predict Subtalar Joint instability. Distinction between chronic lateral ankle instability and Subtalar Joint instability remains challenging. Recognition of Subtalar Joint instability as an identifiable and treatable cause of ankle pain requires vigilant clinical investigation. Systematic Review of Level III and Level IV Studies, Level IV.
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can weightbearing computed tomography scans be used to diagnose Subtalar Joint instability a cadaver study
Journal of Orthopaedic Research, 2019Co-Authors: Nicola Krahenbuhl, Nathan P Davidson, Charles L Saltzman, Arne Burssens, Chelsea Mccarty Allen, Heath B Henninger, Alexej BargAbstract:Chronic hindfoot instability is a frequent problem that includes the ankle and/or the Subtalar Joint. While ankle Joint instability can be diagnosed clinically, accurate assessment of the Subtalar Joint remains elusive. This study's purpose was to assess the ability of weightbearing computed tomography (CT) scans to detect Subtalar Joint instability. Seven pairs of fresh frozen male cadavers (tibial plateau to toe-tip) were tested. A radiolucent frame held specimens in a plantigrade position while non-weightbearing and weightbearing CT scans (with and without torque application) were taken. First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent interosseous talo-calcaneal ligament (ITCL) transection, while the contralateral underwent calcaneo-fibular ligament (CFL) transection. Third, the remaining intact ITCL or CFL was transected. Finally, the deltoid ligament was transected in all ankles. Eight radiographic measurements were performed to assess the congruency of the Subtalar Joint on digitally reconstructed radiographs and single CT images. Axial loading did not impact most measurements, whereas torque did impact most measurements. Radiographic measurements performed at the Subtalar Joint level were more reliable and better predictors for Subtalar Joint instability compared with measurements performed at the ankle Joint level. While torque application is crucial to identify Subtalar Joint instability, axial load application should be avoided. Measurements to assess the Subtalar Joint stability should primarily be performed at the Subtalar Joint level rather than at the ankle Joint level when using weightbearing CT scans. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2457-2465, 2019.
Nicola Krahenbuhl - One of the best experts on this subject based on the ideXlab platform.
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interaction of loading and ligament injuries in Subtalar Joint instability quantified by 3d weightbearing computed tomography
Journal of Orthopaedic Research, 2021Co-Authors: Arne Burssens, Nicola Krahenbuhl, Charles L Saltzman, Alexej Barg, Amy L Lenz, Kalebb Howell, Chong Zhang, Yantarat SripanichAbstract:Despite decades of research since its first description, Subtalar Joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two-dimensional measurements. Therefore, we used weightbearing CT imaging to quantify three-dimensional displacement associated with Subtalar Joint instability. Three-dimensional models were generated in seven paired cadaver specimens to compute talocalcaneal displacement after different patterns of axial load (85kg) combined with torque in internal and external rotation (10Nm). Sequential imaging was repeated in the Subtalar Joint containing intact ligaments to determine reference displacement. Afterwards the interosseus talo-calcaneal ligament (ITCL) or calcaneofibular ligament (CFL) was sectioned, then the ITCL with CFL and after the ITCL, CFL with the deltoid ligament (DL). The highest translation could be detected in the dorsal direction and the highest rotation occurred in the internaldirection, when external torque was applied to the foot without load. These displacements differed significantly from the condition containing intact ligaments, with a mean difference of 1.6 mm (95% CI, 1.3 to 1.9) for dorsal translation and mean of 12.4° (95% CI, 10.1 to 14.8) for internal rotation. Clinical relevance- Our study provides a novel and non-invasive analysis to quantify Subtalar Joint instability based on three-dimensional WBCT imaging. This approach overcomes former studies using trans-osseous fixation to determine three-dimensional Subtalar Joint displacement and implements an imaging device and software modalities that are readily available. Based on our findings, we recommend applying torque inexternal rotation to the foot to optimize detection of Subtalar Joint instability. This article is protected by copyright. All rights reserved.
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morphologic analysis of the Subtalar Joint using statistical shape modeling
Journal of Orthopaedic Research, 2020Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Charles L Saltzman, Alexej Barg, Amy L Lenz, Rich Lisonbee, Andrew C Peterson, Penny R Atkins, Andrew E AndersonAbstract:Weightbearing computed tomography (WBCT) enables visualization of the foot and ankle as patients stand under load. Clinical measurements of WBCT images are generally limited to two-dimensions, which reduces the ability to quantify complex morphology of individual osseous structures as well as the alignment between two or more bones. The shape and orientation of the healthy/normal Subtalar Joint, in particular, is not well-understood, which makes it very difficult to diagnose Subtalar pathoanatomy. Herein, we employed statistical shape modeling to evaluate three-dimensional (3D) shape variation, coverage, space, and congruency of the Subtalar Joint using WBCT data of 27 asymptomatic healthy individuals. The four most relevant findings were: (A) talar and calcaneal anatomical differences were found regarding the presence of (a) the talar posterior process, (b) calcaneal pitch, and (c) curvature of the calcaneal posterior facet; (B) the talar posterior facet articular surface area was significantly greater than the calcaneal posterior facet articular surface area; (C) the posterior facet varied in Joint space distance, whereas the anteromedial facet was even; and (D) the posterior and anteromedial facet of the Subtalar Joint was consistently congruent. Despite considerable shape variation across the population, the posterior and anteromedial articular facets of the Subtalar Joint were consistently congruent. Results provide a detailed 3D analysis of the Subtalar Joint under a weightbearing condition in a healthy population which can be used for comparisons to pathological patient populations. The described SSM approach also shows promise for clinical evaluation of the Subtalar Joint from 3D surface reconstructions of WBCT images.
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currently used imaging options cannot accurately predict Subtalar Joint instability
Knee Surgery Sports Traumatology Arthroscopy, 2019Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Maxwell W Weinberg, Nathan P Davidson, Megan K Mills, Charles L Saltzman, Alexej BargAbstract:To give a systematic overview of current diagnostic imaging options and surgical treatment for chronic Subtalar Joint instability. A systematic literature search across the following sources was performed: PubMed, ScienceDirect, and SpringerLink. Twenty-three imaging studies and 19 outcome studies were included. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2) tool was used to assess the methodologic quality of the imaging articles, while the modified Coleman Score was used to assess the methodologic quality of the outcome studies. Conventional radiographs were most frequently used to assess chronic Subtalar Joint instability. Talar tilt, anterior talar translation, and Subtalar tilt were the three most commonly used measurement methods. Surgery often included calcaneofibular ligament reconstruction. Current imaging options do not reliably predict Subtalar Joint instability. Distinction between chronic lateral ankle instability and Subtalar Joint instability remains challenging. Recognition of Subtalar Joint instability as an identifiable and treatable cause of ankle pain requires vigilant clinical investigation. Systematic Review of Level III and Level IV Studies, Level IV.
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can weightbearing computed tomography scans be used to diagnose Subtalar Joint instability a cadaver study
Journal of Orthopaedic Research, 2019Co-Authors: Nicola Krahenbuhl, Nathan P Davidson, Charles L Saltzman, Arne Burssens, Chelsea Mccarty Allen, Heath B Henninger, Alexej BargAbstract:Chronic hindfoot instability is a frequent problem that includes the ankle and/or the Subtalar Joint. While ankle Joint instability can be diagnosed clinically, accurate assessment of the Subtalar Joint remains elusive. This study's purpose was to assess the ability of weightbearing computed tomography (CT) scans to detect Subtalar Joint instability. Seven pairs of fresh frozen male cadavers (tibial plateau to toe-tip) were tested. A radiolucent frame held specimens in a plantigrade position while non-weightbearing and weightbearing CT scans (with and without torque application) were taken. First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent interosseous talo-calcaneal ligament (ITCL) transection, while the contralateral underwent calcaneo-fibular ligament (CFL) transection. Third, the remaining intact ITCL or CFL was transected. Finally, the deltoid ligament was transected in all ankles. Eight radiographic measurements were performed to assess the congruency of the Subtalar Joint on digitally reconstructed radiographs and single CT images. Axial loading did not impact most measurements, whereas torque did impact most measurements. Radiographic measurements performed at the Subtalar Joint level were more reliable and better predictors for Subtalar Joint instability compared with measurements performed at the ankle Joint level. While torque application is crucial to identify Subtalar Joint instability, axial load application should be avoided. Measurements to assess the Subtalar Joint stability should primarily be performed at the Subtalar Joint level rather than at the ankle Joint level when using weightbearing CT scans. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2457-2465, 2019.
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influence of the ankle position and x ray beam angulation on the projection of the posterior facet of the Subtalar Joint
Skeletal Radiology, 2019Co-Authors: Amy L Lenz, Nicola Krahenbuhl, Beat Hintermann, Charles L Saltzman, Rich Lisonbee, Kalebb Howell, Alexej BargAbstract:Using digitally reconstructed radiographs (DRRs), we determined how changes in the projection angle influenced the assessment of the Subtalar Joint. Weightbearing computed tomography (CT) scans were acquired in 27 healthy individuals. CT scans were segmented and processed to create DRRs of the hindfoot. DRRs were obtained to represent 25 different perspectives to simulate internal rotation of the ankle with and without caudal angulation of the X-ray beam. Subtalar Joint morphology was quantified by determining the Joint space curvature, Subtalar inclination angle (SIA), calcaneal slope (CS), and projection of the Subtalar Joint line on three-dimensional (3-D) reconstructions of the calcaneus. The curvature of the projected Joint space was altered substantially over the different DRR projections. Simulated caudal angulation of the X-ray beam with respect to the ankle decreased the SIA and CS significantly. Internal rotation also had a significant impact on the SIA and CS if the X-ray beam was in neutral or in 10° of caudal angulation. An antero-posterior (AP) view of the ankle showed the posterior area of the posterior facet, whereas a more anterior area was visible with internal rotation of the foot and caudal angulation of the X-ray beam. Internal rotation of the foot of 20° is recommended to assess the posterior aspect of the posterior facet, whereas a combined 20° internal rotation of the foot and 40° caudal angulation of the X-ray beam is best to assess the anterior aspect of the posterior facet of the Subtalar Joint.
Charles L Saltzman - One of the best experts on this subject based on the ideXlab platform.
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interaction of loading and ligament injuries in Subtalar Joint instability quantified by 3d weightbearing computed tomography
Journal of Orthopaedic Research, 2021Co-Authors: Arne Burssens, Nicola Krahenbuhl, Charles L Saltzman, Alexej Barg, Amy L Lenz, Kalebb Howell, Chong Zhang, Yantarat SripanichAbstract:Despite decades of research since its first description, Subtalar Joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two-dimensional measurements. Therefore, we used weightbearing CT imaging to quantify three-dimensional displacement associated with Subtalar Joint instability. Three-dimensional models were generated in seven paired cadaver specimens to compute talocalcaneal displacement after different patterns of axial load (85kg) combined with torque in internal and external rotation (10Nm). Sequential imaging was repeated in the Subtalar Joint containing intact ligaments to determine reference displacement. Afterwards the interosseus talo-calcaneal ligament (ITCL) or calcaneofibular ligament (CFL) was sectioned, then the ITCL with CFL and after the ITCL, CFL with the deltoid ligament (DL). The highest translation could be detected in the dorsal direction and the highest rotation occurred in the internaldirection, when external torque was applied to the foot without load. These displacements differed significantly from the condition containing intact ligaments, with a mean difference of 1.6 mm (95% CI, 1.3 to 1.9) for dorsal translation and mean of 12.4° (95% CI, 10.1 to 14.8) for internal rotation. Clinical relevance- Our study provides a novel and non-invasive analysis to quantify Subtalar Joint instability based on three-dimensional WBCT imaging. This approach overcomes former studies using trans-osseous fixation to determine three-dimensional Subtalar Joint displacement and implements an imaging device and software modalities that are readily available. Based on our findings, we recommend applying torque inexternal rotation to the foot to optimize detection of Subtalar Joint instability. This article is protected by copyright. All rights reserved.
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morphologic analysis of the Subtalar Joint using statistical shape modeling
Journal of Orthopaedic Research, 2020Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Charles L Saltzman, Alexej Barg, Amy L Lenz, Rich Lisonbee, Andrew C Peterson, Penny R Atkins, Andrew E AndersonAbstract:Weightbearing computed tomography (WBCT) enables visualization of the foot and ankle as patients stand under load. Clinical measurements of WBCT images are generally limited to two-dimensions, which reduces the ability to quantify complex morphology of individual osseous structures as well as the alignment between two or more bones. The shape and orientation of the healthy/normal Subtalar Joint, in particular, is not well-understood, which makes it very difficult to diagnose Subtalar pathoanatomy. Herein, we employed statistical shape modeling to evaluate three-dimensional (3D) shape variation, coverage, space, and congruency of the Subtalar Joint using WBCT data of 27 asymptomatic healthy individuals. The four most relevant findings were: (A) talar and calcaneal anatomical differences were found regarding the presence of (a) the talar posterior process, (b) calcaneal pitch, and (c) curvature of the calcaneal posterior facet; (B) the talar posterior facet articular surface area was significantly greater than the calcaneal posterior facet articular surface area; (C) the posterior facet varied in Joint space distance, whereas the anteromedial facet was even; and (D) the posterior and anteromedial facet of the Subtalar Joint was consistently congruent. Despite considerable shape variation across the population, the posterior and anteromedial articular facets of the Subtalar Joint were consistently congruent. Results provide a detailed 3D analysis of the Subtalar Joint under a weightbearing condition in a healthy population which can be used for comparisons to pathological patient populations. The described SSM approach also shows promise for clinical evaluation of the Subtalar Joint from 3D surface reconstructions of WBCT images.
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compensatory motion of the Subtalar Joint following tibiotalar arthrodesis an in vivo dual fluoroscopy imaging study
Journal of Bone and Joint Surgery American Volume, 2020Co-Authors: Amy L Lenz, Charles L Saltzman, Alexej Barg, Jennifer A Nichols, Koren E Roach, Bo K Foreman, Andrew E AndersonAbstract:Background Tibiotalar arthrodesis is a common treatment for end-stage tibiotalar osteoarthritis, and is associated with a long-term risk of concomitant Subtalar osteoarthritis. It has been clinically hypothesized that Subtalar osteoarthritis following tibiotalar arthrodesis is the product of compensatory Subtalar Joint hypermobility. However, in vivo measurements of Subtalar Joint motion following tibiotalar arthrodesis have not been quantified. Using dual-fluoroscopy motion capture, we tested the hypothesis that the Subtalar Joint of the limb with a tibiotalar arthrodesis would demonstrate differences in kinematics and increased range of motion compared with the Subtalar Joint of the contralateral, asymptomatic, untreated ankle. Methods Ten asymptomatic patients who had undergone unilateral tibiotalar arthrodesis at a mean (and standard deviation) of 4.0 ± 1.8 years previously were evaluated during overground walking and a double heel-rise task. The evaluation involved markerless tracking with use of dual fluoroscopy integrated with 3-dimensional computed tomography, which allowed for dynamic measurements of Subtalar and tibiotalar dorsiflexion-plantar flexion, inversion-eversion, and internal-external rotation. Range of motion, stance time, swing time, step length, and step width were also measured. Results During the early stance phase of walking, the Subtalar Joint of the limb that had been treated with arthrodesis was plantar flexed (-4.7° ± 3.3°), whereas the Subtalar Joint of the untreated limb was dorsiflexed (4.6° ± 2.2°). Also, during the early stance phase of walking, eversion of the Subtalar Joint of the surgically treated limb (0.2° ± 2.3°) was less than that of the untreated limb (4.5° ± 3.2°). During double heel-rise, the treated limb exhibited increased peak Subtalar plantar flexion (-7.1° ± 4.1°) compared with the untreated limb (0.2° ± 1.8°). Conclusions A significant increase in Subtalar Joint plantar flexion was found to be a primary compensation during overground walking and a double heel-rise activity following tibiotalar arthrodesis. Clinical relevance Significant Subtalar Joint plantar flexion compensations appear to occur following tibiotalar arthrodesis. We found an increase in Subtalar plantar flexion and considered the potential relationship of this finding with the increased rate of Subtalar osteoarthritis that occurs following ankle arthrodesis.
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currently used imaging options cannot accurately predict Subtalar Joint instability
Knee Surgery Sports Traumatology Arthroscopy, 2019Co-Authors: Nicola Krahenbuhl, Beat Hintermann, Maxwell W Weinberg, Nathan P Davidson, Megan K Mills, Charles L Saltzman, Alexej BargAbstract:To give a systematic overview of current diagnostic imaging options and surgical treatment for chronic Subtalar Joint instability. A systematic literature search across the following sources was performed: PubMed, ScienceDirect, and SpringerLink. Twenty-three imaging studies and 19 outcome studies were included. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2) tool was used to assess the methodologic quality of the imaging articles, while the modified Coleman Score was used to assess the methodologic quality of the outcome studies. Conventional radiographs were most frequently used to assess chronic Subtalar Joint instability. Talar tilt, anterior talar translation, and Subtalar tilt were the three most commonly used measurement methods. Surgery often included calcaneofibular ligament reconstruction. Current imaging options do not reliably predict Subtalar Joint instability. Distinction between chronic lateral ankle instability and Subtalar Joint instability remains challenging. Recognition of Subtalar Joint instability as an identifiable and treatable cause of ankle pain requires vigilant clinical investigation. Systematic Review of Level III and Level IV Studies, Level IV.
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can weightbearing computed tomography scans be used to diagnose Subtalar Joint instability a cadaver study
Journal of Orthopaedic Research, 2019Co-Authors: Nicola Krahenbuhl, Nathan P Davidson, Charles L Saltzman, Arne Burssens, Chelsea Mccarty Allen, Heath B Henninger, Alexej BargAbstract:Chronic hindfoot instability is a frequent problem that includes the ankle and/or the Subtalar Joint. While ankle Joint instability can be diagnosed clinically, accurate assessment of the Subtalar Joint remains elusive. This study's purpose was to assess the ability of weightbearing computed tomography (CT) scans to detect Subtalar Joint instability. Seven pairs of fresh frozen male cadavers (tibial plateau to toe-tip) were tested. A radiolucent frame held specimens in a plantigrade position while non-weightbearing and weightbearing CT scans (with and without torque application) were taken. First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent interosseous talo-calcaneal ligament (ITCL) transection, while the contralateral underwent calcaneo-fibular ligament (CFL) transection. Third, the remaining intact ITCL or CFL was transected. Finally, the deltoid ligament was transected in all ankles. Eight radiographic measurements were performed to assess the congruency of the Subtalar Joint on digitally reconstructed radiographs and single CT images. Axial loading did not impact most measurements, whereas torque did impact most measurements. Radiographic measurements performed at the Subtalar Joint level were more reliable and better predictors for Subtalar Joint instability compared with measurements performed at the ankle Joint level. While torque application is crucial to identify Subtalar Joint instability, axial load application should be avoided. Measurements to assess the Subtalar Joint stability should primarily be performed at the Subtalar Joint level rather than at the ankle Joint level when using weightbearing CT scans. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2457-2465, 2019.
Gregory S. Lewis - One of the best experts on this subject based on the ideXlab platform.
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Effects of Medial Displacement Calcaneal Osteotomy and Calcaneal Z Osteotomy on Subtalar Joint Pressures: A Cadaveric Flatfoot Model
The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons, 2016Co-Authors: Nathan Patrick, Evan P. Roush, Gregory S. Lewis, Allen R. Kunselman, Jarrett D. CainAbstract:Medial displacement calcaneal osteotomies have been shown to be successful in the surgical management of adult acquired flatfoot, in particular, stage 2 deformity. Classically, the medial displacement calcaneal osteotomy technique has been performed. However, a calcaneal Z osteotomy has been more recently described and applied in the surgical management of flatfoot deformity. Although the potential advantages of the calcaneal Z technique have been reported, data on its effect on the Subtalar Joint are lacking. A validated flatfoot model was induced in 8 cadaveric feet that had been randomly assigned to either medial displacement calcaneal osteotomy (n = 4) or calcaneal Z osteotomy (n = 4). The feet were loaded through the tibia with a constant ground reaction force of 400 N, with a simultaneous increase in the Achilles tendon force to 300 or 500 N. The Subtalar Joint pressures were recorded before and after osteotomy. We did not detect any statistically significant differences between the 2 techniques in terms of their effects on Subtalar Joint pressure.
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in vivo tests of an improved method for functional location of the Subtalar Joint axis
Journal of Biomechanics, 2009Co-Authors: Gregory S. Lewis, Kevin A. Kirby, Tamara L Cohen, Andrea R Seisler, Frances T Sheehan, Stephen J PiazzaAbstract:The Subtalar Joint is important in frontal plane movement and posture of the hindfoot. Abnormal Subtalar Joint moments caused by muscle forces and the ground reaction force acting on the foot are thought to play a role in various foot deformities. Calculating Joint moments typically requires knowledge of the location of the Joint axis; however, location of the Subtalar axis from measured movement is difficult because the talus cannot be tracked using skin-mounted markers. The accuracy of a novel technique for locating the Subtalar axis was assessed in vivo using magnetic resonance imaging. The method was also tested with skin-mounted markers and video motion analysis. The technique involves applying forces to the foot that cause pure Subtalar Joint motion (with negligible talocrural Joint motion), and then using helical axis decomposition of the resulting tibiocalcaneal motion. The resulting Subtalar axis estimates differed by 6 degrees on average from the true best-fit Subtalar axes in the MRI tests. Motion was found to have been applied primarily about the Subtalar Joint with an average of only 3 degrees of talocrural Joint motion. The proposed method provides a potential means for obtaining subject-specific Subtalar axis estimates which can then be used in inverse dynamic analyses and subject-specific musculoskeletal models.
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determination of Subtalar Joint axis location by restriction of talocrural Joint motion
Gait & Posture, 2007Co-Authors: Gregory S. Lewis, Kevin A. Kirby, Stephen J PiazzaAbstract:The location of the Subtalar Joint axis is an important determinant of the mechanical function of the foot. The moments of muscle forces and of the ground reaction force about the Subtalar Joint are dependent upon the location of this Joint axis. There is substantial variation in Subtalar axis location across subjects, but current methods for determining its location are often invasive or involve expensive imaging protocols. A novel technique for location of the Subtalar axis is presented in which the talocrural Joint is passively immobilized so that motion of the tibia relative to the calcaneus can be used to estimate the Subtalar axis. This paper presents results of cadaver testing in which accuracy of the technique was assessed by comparing helical axes computed from calcaneus-tibia bone motions to axes computed from calcaneus-talus bone motions. Only small motions at the talocrural Joint were observed, and good estimates of the Subtalar axis (errors less than 15° and 2 mm) were achieved in four of six specimens.
Stephen J Piazza - One of the best experts on this subject based on the ideXlab platform.
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in vivo tests of an improved method for functional location of the Subtalar Joint axis
Journal of Biomechanics, 2009Co-Authors: Gregory S. Lewis, Kevin A. Kirby, Tamara L Cohen, Andrea R Seisler, Frances T Sheehan, Stephen J PiazzaAbstract:The Subtalar Joint is important in frontal plane movement and posture of the hindfoot. Abnormal Subtalar Joint moments caused by muscle forces and the ground reaction force acting on the foot are thought to play a role in various foot deformities. Calculating Joint moments typically requires knowledge of the location of the Joint axis; however, location of the Subtalar axis from measured movement is difficult because the talus cannot be tracked using skin-mounted markers. The accuracy of a novel technique for locating the Subtalar axis was assessed in vivo using magnetic resonance imaging. The method was also tested with skin-mounted markers and video motion analysis. The technique involves applying forces to the foot that cause pure Subtalar Joint motion (with negligible talocrural Joint motion), and then using helical axis decomposition of the resulting tibiocalcaneal motion. The resulting Subtalar axis estimates differed by 6 degrees on average from the true best-fit Subtalar axes in the MRI tests. Motion was found to have been applied primarily about the Subtalar Joint with an average of only 3 degrees of talocrural Joint motion. The proposed method provides a potential means for obtaining subject-specific Subtalar axis estimates which can then be used in inverse dynamic analyses and subject-specific musculoskeletal models.
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determination of Subtalar Joint axis location by restriction of talocrural Joint motion
Gait & Posture, 2007Co-Authors: Gregory S. Lewis, Kevin A. Kirby, Stephen J PiazzaAbstract:The location of the Subtalar Joint axis is an important determinant of the mechanical function of the foot. The moments of muscle forces and of the ground reaction force about the Subtalar Joint are dependent upon the location of this Joint axis. There is substantial variation in Subtalar axis location across subjects, but current methods for determining its location are often invasive or involve expensive imaging protocols. A novel technique for location of the Subtalar axis is presented in which the talocrural Joint is passively immobilized so that motion of the tibia relative to the calcaneus can be used to estimate the Subtalar axis. This paper presents results of cadaver testing in which accuracy of the technique was assessed by comparing helical axes computed from calcaneus-tibia bone motions to axes computed from calcaneus-talus bone motions. Only small motions at the talocrural Joint were observed, and good estimates of the Subtalar axis (errors less than 15° and 2 mm) were achieved in four of six specimens.
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mechanics of the Subtalar Joint and its function during walking
Foot and Ankle Clinics of North America, 2005Co-Authors: Stephen J PiazzaAbstract:Knowledge of the location of the Subtalar Joint axis in individual patients would permit clinical assessment of the forces and moments that produce frontal-plane foot and ankle deformities. Biomechanical analysis of the Subtalar Joint is hindered, however, by the inaccessibility of the talus, which makes locating the Joint axis difficult, and by the high degree of intersubject anatomic variation. This article discusses work done with cadaver specimens and using invasive methods in vivo that has enhanced our understanding of the mechanics of the Subtalar Joint and its function during gait. Also reviewed are investigations of the actions of muscles that cross the Subtalar Joint.
