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Thomas D Brown - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Hallux Sesamoid Resection on the Effective Moment of the
2016Co-Authors: Flexor Hallucis Brevis, Rhonda L Aper, Charles L Saltzman, Thomas D Brown, Ph. DAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint.) The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial sesa-moid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalan-geal joint were tested, ranging from-loo to 50°. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs de-creased significantly (P c.05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of-loo and 1 5 O (4.3 % and 2.4%, respectively) and largest at dorsiflexion angles of 25O, 35O, and 50 ° (29.2%, 22.4%, and 26.7%, respec-tively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial ses-amoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. How-ever, this mechanical advantage may be profoundly dimin-ished by excision of both hallux Sesamoids
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely understood. The effects of selective Sesamoid resections on the effective tendon moment arm of the flexor hallucis longus tendon were evaluated. Twelve fresh frozen cadaver first rays were each mounted in a device that held rigid the metatarsal. A ramp-controlled displacement of an MTS ram supplied a functional load input force to the flexor hallucis longus. The components of the resultant output force necessary to resist the input flexor hallucis longus force were transduced simultaneously by a multicomponent load cell. Subsequently, 3 progressively more extensive seasamoid resections were done: (1) distal hemiresection, (2) complete resection, and (3) resection of both Sesamoids. Six specimens were tested with the medial Sesamoid removed first and 6 with the lateral Sesamoid removed first. Statistical analysis showed that significant decreases in the effective tendon moment arms occurred with full medial Sesamoid resection, full lateral Sesamoid resection, and resection of both the medial and lateral Sesamoids.
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely u
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the effect of hallux Sesamoid resection on the effective moment of the flexor hallucis brevis
Foot & Ankle International, 1994Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint). The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial Sesamoid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalangeal joint were tested, ranging from -10 degrees to 50 degrees. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs decreased significantly (P < .05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of -10 degrees and 15 degrees (4.3% and 2.4%, respectively) and largest at dorsiflexion angles of 25 degrees, 35 degrees, and 50 degrees (29.2%, 22.4%, and 26.7%, respectively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial Sesamoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. However, this mechanical advantage may be profoundly diminished by excision of both hallux Sesamoids.
Rhonda L Aper - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Hallux Sesamoid Resection on the Effective Moment of the
2016Co-Authors: Flexor Hallucis Brevis, Rhonda L Aper, Charles L Saltzman, Thomas D Brown, Ph. DAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint.) The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial sesa-moid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalan-geal joint were tested, ranging from-loo to 50°. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs de-creased significantly (P c.05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of-loo and 1 5 O (4.3 % and 2.4%, respectively) and largest at dorsiflexion angles of 25O, 35O, and 50 ° (29.2%, 22.4%, and 26.7%, respec-tively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial ses-amoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. How-ever, this mechanical advantage may be profoundly dimin-ished by excision of both hallux Sesamoids
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely understood. The effects of selective Sesamoid resections on the effective tendon moment arm of the flexor hallucis longus tendon were evaluated. Twelve fresh frozen cadaver first rays were each mounted in a device that held rigid the metatarsal. A ramp-controlled displacement of an MTS ram supplied a functional load input force to the flexor hallucis longus. The components of the resultant output force necessary to resist the input flexor hallucis longus force were transduced simultaneously by a multicomponent load cell. Subsequently, 3 progressively more extensive seasamoid resections were done: (1) distal hemiresection, (2) complete resection, and (3) resection of both Sesamoids. Six specimens were tested with the medial Sesamoid removed first and 6 with the lateral Sesamoid removed first. Statistical analysis showed that significant decreases in the effective tendon moment arms occurred with full medial Sesamoid resection, full lateral Sesamoid resection, and resection of both the medial and lateral Sesamoids.
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely u
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the effect of hallux Sesamoid resection on the effective moment of the flexor hallucis brevis
Foot & Ankle International, 1994Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint). The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial Sesamoid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalangeal joint were tested, ranging from -10 degrees to 50 degrees. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs decreased significantly (P < .05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of -10 degrees and 15 degrees (4.3% and 2.4%, respectively) and largest at dorsiflexion angles of 25 degrees, 35 degrees, and 50 degrees (29.2%, 22.4%, and 26.7%, respectively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial Sesamoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. However, this mechanical advantage may be profoundly diminished by excision of both hallux Sesamoids.
Charles L Saltzman - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Hallux Sesamoid Resection on the Effective Moment of the
2016Co-Authors: Flexor Hallucis Brevis, Rhonda L Aper, Charles L Saltzman, Thomas D Brown, Ph. DAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint.) The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial sesa-moid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalan-geal joint were tested, ranging from-loo to 50°. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs de-creased significantly (P c.05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of-loo and 1 5 O (4.3 % and 2.4%, respectively) and largest at dorsiflexion angles of 25O, 35O, and 50 ° (29.2%, 22.4%, and 26.7%, respec-tively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial ses-amoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. How-ever, this mechanical advantage may be profoundly dimin-ished by excision of both hallux Sesamoids
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assessing Sesamoid subluxation how good is the ap radiograph
Foot & Ankle International, 1998Co-Authors: Kyle D Talbot, Charles L SaltzmanAbstract:Subluxation of the metatarsoSesamoid joints frequently occurs with the development of hallux valgus deformity, and the restoration of a normal metatarsoSesamoid articulation has been proposed as essential for achieving a biomechanically sound operative result. The position of the Sesamoid bones on the AP radiograph is used often to assess the pre- and postoperative relationship between the hallucal Sesamoids and the metatarsal sulci. We evaluated the validity of this approach. Thirty subjects with hallux valgus and 30 control subjects participated in this study by undergoing both AP and tangential weightbearing radiographs. The Sesamoid station on the AP radiographs was compared with the position of the Sesamoids on tangential radiographs, using a new continuous measure to estimate subluxation. In approximately half of the cases, we found a difference between the apparent Sesamoid station on the AP radiograph and the true position on the tangential one. Increased metatarsal rotation was associated with misclassification of the Sesamoid station on the AP radiograph. We conclude that the standard method for measuring the Sesamoid station on the AP radiograph is not valid. Surgeons wishing to evaluate the metatarsoSesamoid joint should obtain weightbearing tangential radiographs.
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely understood. The effects of selective Sesamoid resections on the effective tendon moment arm of the flexor hallucis longus tendon were evaluated. Twelve fresh frozen cadaver first rays were each mounted in a device that held rigid the metatarsal. A ramp-controlled displacement of an MTS ram supplied a functional load input force to the flexor hallucis longus. The components of the resultant output force necessary to resist the input flexor hallucis longus force were transduced simultaneously by a multicomponent load cell. Subsequently, 3 progressively more extensive seasamoid resections were done: (1) distal hemiresection, (2) complete resection, and (3) resection of both Sesamoids. Six specimens were tested with the medial Sesamoid removed first and 6 with the lateral Sesamoid removed first. Statistical analysis showed that significant decreases in the effective tendon moment arms occurred with full medial Sesamoid resection, full lateral Sesamoid resection, and resection of both the medial and lateral Sesamoids.
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the effect of hallux Sesamoid excision on the flexor hallucis longus moment arm
Clinical Orthopaedics and Related Research, 1996Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:Surgical treatments for chronic, painful hallux Sesamoid disorders typically involve partial or complete resection of 1 or both Sesamoids. Although these approaches generally result in satisfactory symptom relief, their effect on biomechanical function of the major hallux flexors is not completely u
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the effect of hallux Sesamoid resection on the effective moment of the flexor hallucis brevis
Foot & Ankle International, 1994Co-Authors: Rhonda L Aper, Charles L Saltzman, Thomas D BrownAbstract:In this cadaver study, the functional significance of the hallux Sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint). The intact case was compared with three levels of progressive Sesamoid resection: distal half of the medial Sesamoid excised, entire medial Sesamoid excised, and both the medial and lateral Sesamoids excised. Five dorsiflexion angles of the metatarsophalangeal joint were tested, ranging from -10 degrees to 50 degrees. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs decreased significantly (P < .05) only with the excision of both Sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of -10 degrees and 15 degrees (4.3% and 2.4%, respectively) and largest at dorsiflexion angles of 25 degrees, 35 degrees, and 50 degrees (29.2%, 22.4%, and 26.7%, respectively). The clinical significance of the results is that distal hemiresection of the medial Sesamoid or full medial Sesamoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. However, this mechanical advantage may be profoundly diminished by excision of both hallux Sesamoids.
Heidi L Reesink - One of the best experts on this subject based on the ideXlab platform.
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can quantitative computed tomography detect bone morphological changes associated with catastrophic proximal Sesamoid bone fracture in thoroughbred racehorses
Equine Veterinary Journal, 2019Co-Authors: Erin N Cresswell, S P Mcdonough, Scott Palmer, Christopher J Hernandez, Heidi L ReesinkAbstract:BACKGROUND: Fracture of the proximal Sesamoid bones continues to be the most common fatal musculoskeletal injury in US racehorses. Identifying factors that influence fracture risk could lead to screening techniques to reduce catastrophic injury rates and improve animal welfare. OBJECTIVES: To identify morphological differences between proximal Sesamoid bones of the contralateral limb of fracture and control horses and assess the feasibility of computed tomography (CT) to detect traits associated with proximal Sesamoid bone fracture. We hypothesised that horses with proximal Sesamoid bone fracture would have greater bone density. STUDY DESIGN: Cross-sectional cadaver morphological study. METHODS: Proximal Sesamoid bone morphology was measured using high-resolution micro-CT images from 16 Thoroughbred racehorses (eight fracture, eight control) euthanised on New York racetracks. Nominal logistic regression models and receiver operating characteristic curves were created to assess the ability of CT-derived morphological traits to accurately classify fracture horses vs. controls. RESULTS: Bone volume fraction was greater in the fracture group (90.39 ± 1.76%) as compared to controls (87.20 ± 2.79%, P<0.0001). Bone volume fraction, bone width, trabecular thickness and degree of anisotropy were significantly different between fracture and control horses. Receiver operating characteristic curves showed that a combined model that incorporates bone volume fraction and width can identify fracture from control horses with an area under the curve of 0.938, indicating high accuracy at classifying fracture horses from controls. MAIN LIMITATIONS: The number of horses per group is small, although the total number of Sesamoids imaged is reasonable (n = 62). In vivo CT at the resolution performed in this study is currently unattainable; however, density and width could be measured with quantitative CT. CONCLUSIONS: Differences in proximal Sesamoid bone morphology were identified between fracture and control horses. As improved technology becomes accessible, quantitative CT could potentially be used as a clinical imaging technique to estimate proximal Sesamoid bone fracture risk in Thoroughbred racehorses.
Norberto P Giannini - One of the best experts on this subject based on the ideXlab platform.
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morphology and evolution of Sesamoid elements in bats mammalia chiroptera
American Museum Novitates, 2018Co-Authors: Lucila Ines Amador, Virginia Abdala, Norberto P Giannini, Nancy B SimmonsAbstract:ABSTRACT Sesamoids are skeletal elements found within a tendon or ligament as it passes around a joint or bony prominence. Here we review the distribution of Sesamoids in bats, the only mammals capable of powered flight. Our survey included bat species representing most extant families as well as two key Eocene fossil bats in which Sesamoids are exquisitely preserved, Onychonycteris finneyi and Icaronycteris index. We identified 46 separate Sesamoid elements (or sets of elements) from dissections of selected bat taxa, with no more than 23 of these present in any given species. Among the Sesamoids identified in our survey, 12 have not previously been described in bats. We also identified seven Sesamoids previously described in the literature that are not present in our sample of species. No Sesamoids were found to be exclusive to the fossil taxa in our study; all the Sesamoids observed in Onychonycteris and Icaronycteris have apparent homologs among extant species. We mapped the presence/absence of the 46 ...
