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Thay Q Lee - One of the best experts on this subject based on the ideXlab platform.
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effects of Humeral component Neck angle and version of reverse total shoulder prosthesis biomechanical stud
Journal of Bone and Joint Surgery-british Volume, 2016Co-Authors: Thay Q Lee, Michelle H Mcgarry, Daniel StephensonAbstract:Introduction Reverse total shoulder arthroplasty continues to have a high complication rate, specifically with component instability and scapular notching. Therefore, the purpose of this study was to quantify the effects of Humeral component Neck angle and version on impingement free range of motion. Methods A total of 13 cadaveric shoulders (4 males and 9 females, average age = 69 years, range 46 to 96 years) were randomly assigned to two studies. Study 1 investigated the effects of Humeral component Neck angle (n=6) and Study 2 investigated the effects of Humeral component version (n=7). For all shoulders, Tornier Aequalis® Reversed Shoulder implants (Edina, MN) were used. For study 1, the implants were modified to 135, 145 and 155 degree Humeral Neck shaft angles and for Study 2 a custom implant that allowed control of Humeral head version were used. For biomechanical testing, a custom shoulder testing system that permits independent loading of all shoulder muscles with six degree of freedom positioning was used. (Figure 1) Internal control experimental design was used where all conditions were tested on the same specimen. Study 1 The adduction angle and internal/external Humeral rotation angle at which impingement occurred were measured. GlenoHumeral abduction moment was measured at 0 and 30 degrees of abduction, and anterior dislocation forces were measured at 30 degrees of internal rotation, 0 and 30 degrees of external rotation with and without subscapularis loading. Study 2 The degree of internal and external rotation when impingement occurred was measured at 0, 30 and 60 degrees of glenoHumeral abduction in the scapular plane with the Humeral component placed in 20 degrees of anteversion, neutral version, 20 degrees of retroversion, and 40 degrees of retroversion. Statistical analysis was performed with a repeated measures analysis of variance with a Tukey post-hoc test with a significance level of 0.05. Results Study 1 Adduction deficit angles for 155, 145, and 135 degree Neck-shaft angle were 2 ± 5 degrees of abduction, 7 ± 4 degrees of adduction, and 12 ± 2 degrees of adduction (P Study 2 Maximum external rotation was the limiting position for impingement particularly at 0 degrees of abduction. Maximum external rotation before impingement occurred increased significantly with increasing Humeral retroversion (p Conclusion In reverse shoulder arthroplasty, 155 degree Neck-shaft angle was more prone to impingement with adduction but had the advantage of being more stable. In addition, 40 degrees of retroversion has the largest range of Humeral rotation without impingement.
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biomechanical effects of Humeral Neck shaft angle and subscapularis integrity in reverse total shoulder arthroplasty
Journal of Shoulder and Elbow Surgery, 2014Co-Authors: Sangjin Shin, Michelle H Mcgarry, Jonathan Scott, Nathanael Heckmann, Thay Q LeeAbstract:Background The variability in functional outcomes and the occurrence of scapular notching and instability after reverse total shoulder arthroplasty remain problems. The objectives of this study were to measure the effect of reverse Humeral component Neck-shaft angle on impingement-free range of motion, abduction moment, and anterior dislocation force and to evaluate the effect of subscapularis loading on dislocation force. Methods Six cadaveric shoulders were tested with 155°, 145°, and 135° reverse shoulder Humeral Neck-shaft angles. The adduction angle at which bone contact occurred and the internal and external rotational impingement-free range of motion angles were measured. GlenoHumeral abduction moment was measured at 0° and 30° of abduction, and anterior dislocation forces were measured at 30° of internal rotation, 0°, and 30° of external rotation with and without subscapularis loading. Results Adduction deficit angles for 155°, 145°, and 135° Neck-shaft angle were 2° ± 5° of abduction, 7° ± 4° of adduction, and 12° ± 2° of adduction ( P P P Conclusions The 155° Neck-shaft angle was more prone to scapular bone contact during adduction but was more stable at the internally rotated position, which was the least stable Humeral rotation position. Subscapularis loading gave further anterior stability with all Neck-shaft angles at all positions.
Gilles Walch - One of the best experts on this subject based on the ideXlab platform.
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the influence of Humeral Neck shaft angle and glenoid lateralization on range of motion in reverse shoulder arthroplasty
Journal of Shoulder and Elbow Surgery, 2017Co-Authors: Birgit Werner, Jean Chaoui, Gilles WalchAbstract:Background Recent developments in reverse shoulder arthroplasty (RSA) have focused on changes in several design-related parameters, including Humeral component design, to allow for easier convertibility. Alterations in Humeral inclination and offset on shoulder kinematics may have a relevant influence on postoperative outcome. This study used a virtual computer simulation to evaluate the influence of Humeral Neck shaft angle and glenoid lateralization on range of motion in onlay design RSA. Methods Three-dimensional RSA computer templating was created from computed tomography (CT) scans in 20 patients undergoing primary total shoulder arthroplasty for concentric osteoarthritis (Walch A1). Two concurrent factors were tested for impingement-free range of motion: Humeral inclination (135° vs. 145°) and glenoid lateralization (0 mm vs. 5 mm). Results Decreasing the Humeral Neck shaft angle demonstrated a significant increase in impingement-free range of motion. Compared to the 145° configuration, extension was increased by 42.3° (−8.5° to 73.5°), adduction by 15° (10° to 23°), and external rotation with the arm at side by 15.1° (8.5° to 26.5°); however, abduction was decreased by 6.5° (−1° to 12.5°). Glenoid lateralization led to comparable results, but an additional increase in abduction of 7.6° (−1° to 16.5°) and forward flexion of 26.6° (6.5° to 62°) was observed. Conclusion Lower Humeral Neck shaft angle and glenoid lateralization are effective for improvement in range of motion after RSA. The use of the 135° model with 5 mm of glenoid lateralization provided the best results in impingement-free range of motion, except for abduction.
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the reverse total shoulder arthroplasty
Journal of Bone and Joint Surgery American Volume, 2007Co-Authors: Frederick A Matsen, Pascal Boileau, Gilles Walch, Christian Gerber, Ryan T BicknellAbstract:A reverse total shoulder arthroplasty is a procedure considered for patients whose shoulder problem cannot be effectively managed with a conventional total shoulder replacement. The reverse total shoulder prosthesis is based on a concept introduced by Professor Paul Grammont, in which a convex articular surface is fixed to the glenoid and a concave articular surface is fixed to the proximal part of the humerus1 (Fig. 1). This prosthesis addresses some of the limitations of conventional arthroplasty. To understand the role of the reverse total shoulder arthroplasty, one must first understand the limitations of conventional arthroplasty. A conventional or anatomic shoulder arthroplasty is the replacement of damaged joint surfaces with prosthetic components that approximate the normal joint surfaces and are stabilized by mechanisms similar to those stabilizing a native glenoHumeral joint. In performing a conventional arthroplasty, the surgeon is faced with the following limitations. ### Limited Ability to Manage GlenoHumeral Translation The normal glenoHumeral joint consists of a small, shallow concave glenoid with a compliant rim for articulation with a spherical Humeral head. The small articular surface and minimal constraint of the glenoid allow a large range of rotational motion before the Humeral Neck abuts on the glenoid rim. They also allow small physiologic translations of the Humeral head on the glenoid in response to loads that are applied tangential to the glenoid joint surface. Translation also occurs at the extremes of glenoHumeral motion, permitting a greater range of motion than would be possible if the Humeral head did not translate. While the compliant rim of the normal glenoid enables full surface contact during small Humeral translations, this attribute is not replicated by the much less compliant polyethylene joint surface of a conventional shoulder arthroplasty. If the prosthetic glenoid surface conforms exactly to the Humeral head (i.e., if each has the same radius of curvature), no translation …
Gregory A. Dumanian - One of the best experts on this subject based on the ideXlab platform.
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targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation a case study
The Lancet, 2007Co-Authors: Kathy Stubblefield, Blair A. Lock, Robert D Lipschutz, Laura A. Miller, Todd A. Kuiken, Paul D. Marasco, Ping Zhou, Gregory A. DumanianAbstract:Summary Background The function of current artificial arms is limited by inadequate control methods. We developed a technique that used nerve transfers to muscle to develop new electromyogram control signals and nerve transfers to skin, to provide a pathway for cutaneous sensory feedback to the missing hand. Methods We did targeted reinnervation surgery on a woman with a left arm amputation at the Humeral Neck. The ulnar, median, musculocutaneous, and distal radial nerves were transferred to separate segments of her pectoral and serratus muscles. Two sensory nerves were cut and the distal ends were anastomosed to the ulnar and median nerves. After full recovery the patient was fit with a new prosthesis using the additional targeted muscle reinnervation sites. Functional testing was done and sensation in the reinnervated skin was quantified. Findings The patient described the control as intuitive; she thought about using her hand or elbow and the prosthesis responded appropriately. Functional testing showed substantial improvement: mean scores in the blocks and box test increased from 4·0 (SD 1·0) with the conventional prosthesis to 15·6 (1·5) with the new prosthesis. Assessment of Motor and Process Skills test scores increased from 0·30 to 1·98 for motor skills and from 0·90 to 1·98 for process skills. The denervated anterior chest skin was reinnervated by both the ulnar and median nerves; the patient felt that her hand was being touched when this chest skin was touched, with near-normal thresholds in all sensory modalities. Interpretation Targeted reinnervation improved prosthetic function and ease of use in this patient. Targeted sensory reinnervation provides a potential pathway for meaningful sensory feedback.
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targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation a case study commentary
The Lancet, 2007Co-Authors: Leigh R. Hochberg, Kathy Stubblefield, Blair A. Lock, Robert D Lipschutz, Laura A. Miller, Dawn M Taylor, Todd A. Kuiken, Paul D. Marasco, Ping Zhou, Gregory A. DumanianAbstract:Background The function of current artificial arms is limited by inadequate control methods. We developed a technique that used nerve transfers to muscle to develop new electromyogram control signals and nerve transfers to skin, to provide a pathway for cutaneous sensory feedback to the missing hand. Methods We did targeted reinnervation surgery on a woman with a left arm amputation at the Humeral Neck. The ulnar, median, musculocutaneous, and distal radial nerves were transferred to separate segments of her pectoral and serratus muscles. Two sensory nerves were cut and the distal ends were anastomosed to the ulnar and median nerves. After full recovery the patient was fit with a new prosthesis using the additional targeted muscle reinnervation sites. Functional testing was done and sensation in the reinnervated skin was quantified. Findings The patient described the control as intuitive; she thought about using her hand or elbow and the prosthesis responded appropriately. Functional testing showed substantial improvement: mean scores in the blocks and box test increased from 4·0 (SD 1·0) with the conventional prosthesis to 15 6 (1·5) with the new prosthesis. Assessment of Motor and Process Skills test scores increased from 0·30 to 1·98 for motor skills and from 0·90 to 1·98 for process skills. The denervated anterior chest skin was reinnervated by both the ulnar and median nerves; the patient felt that her hand was being touched when this chest skin was touched, with near-normal thresholds in all sensory modalities. Interpretation Targeted reinnervation improved prosthetic function and ease of use in this patient. Targeted sensory reinnervation provides a potential pathway for meaningful sensory feedback.
Todd A. Kuiken - One of the best experts on this subject based on the ideXlab platform.
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targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation a case study
The Lancet, 2007Co-Authors: Kathy Stubblefield, Blair A. Lock, Robert D Lipschutz, Laura A. Miller, Todd A. Kuiken, Paul D. Marasco, Ping Zhou, Gregory A. DumanianAbstract:Summary Background The function of current artificial arms is limited by inadequate control methods. We developed a technique that used nerve transfers to muscle to develop new electromyogram control signals and nerve transfers to skin, to provide a pathway for cutaneous sensory feedback to the missing hand. Methods We did targeted reinnervation surgery on a woman with a left arm amputation at the Humeral Neck. The ulnar, median, musculocutaneous, and distal radial nerves were transferred to separate segments of her pectoral and serratus muscles. Two sensory nerves were cut and the distal ends were anastomosed to the ulnar and median nerves. After full recovery the patient was fit with a new prosthesis using the additional targeted muscle reinnervation sites. Functional testing was done and sensation in the reinnervated skin was quantified. Findings The patient described the control as intuitive; she thought about using her hand or elbow and the prosthesis responded appropriately. Functional testing showed substantial improvement: mean scores in the blocks and box test increased from 4·0 (SD 1·0) with the conventional prosthesis to 15·6 (1·5) with the new prosthesis. Assessment of Motor and Process Skills test scores increased from 0·30 to 1·98 for motor skills and from 0·90 to 1·98 for process skills. The denervated anterior chest skin was reinnervated by both the ulnar and median nerves; the patient felt that her hand was being touched when this chest skin was touched, with near-normal thresholds in all sensory modalities. Interpretation Targeted reinnervation improved prosthetic function and ease of use in this patient. Targeted sensory reinnervation provides a potential pathway for meaningful sensory feedback.
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targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation a case study commentary
The Lancet, 2007Co-Authors: Leigh R. Hochberg, Kathy Stubblefield, Blair A. Lock, Robert D Lipschutz, Laura A. Miller, Dawn M Taylor, Todd A. Kuiken, Paul D. Marasco, Ping Zhou, Gregory A. DumanianAbstract:Background The function of current artificial arms is limited by inadequate control methods. We developed a technique that used nerve transfers to muscle to develop new electromyogram control signals and nerve transfers to skin, to provide a pathway for cutaneous sensory feedback to the missing hand. Methods We did targeted reinnervation surgery on a woman with a left arm amputation at the Humeral Neck. The ulnar, median, musculocutaneous, and distal radial nerves were transferred to separate segments of her pectoral and serratus muscles. Two sensory nerves were cut and the distal ends were anastomosed to the ulnar and median nerves. After full recovery the patient was fit with a new prosthesis using the additional targeted muscle reinnervation sites. Functional testing was done and sensation in the reinnervated skin was quantified. Findings The patient described the control as intuitive; she thought about using her hand or elbow and the prosthesis responded appropriately. Functional testing showed substantial improvement: mean scores in the blocks and box test increased from 4·0 (SD 1·0) with the conventional prosthesis to 15 6 (1·5) with the new prosthesis. Assessment of Motor and Process Skills test scores increased from 0·30 to 1·98 for motor skills and from 0·90 to 1·98 for process skills. The denervated anterior chest skin was reinnervated by both the ulnar and median nerves; the patient felt that her hand was being touched when this chest skin was touched, with near-normal thresholds in all sensory modalities. Interpretation Targeted reinnervation improved prosthetic function and ease of use in this patient. Targeted sensory reinnervation provides a potential pathway for meaningful sensory feedback.
Mingming Wang - One of the best experts on this subject based on the ideXlab platform.
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comparison of locking plates and intramedullary nails in treatment of three part or four part proximal Humeral Neck fractures in elderly population a randomized trial protocol
Medicine, 2020Co-Authors: Hua Song, Mingming WangAbstract:Background Locking plate and intramedullary nail are two commonly applied methods to fix proximal Humeral fractures. There are limited randomized studies that specifically evaluate the results of proximal Humeral Neck fractures with three-part or four-part treated by locking plates or intramedullary nails. Our goal was to compare functional outcomes, complications, and imaging features between the two groups. Methods This single-center, prospective, randomized controlled test will be conducted in Tengzhou Central People's Hospital. Patients with these conditions will be included: age between 55 and 80 years; are able to communicate normally and agree to participate in our study; with the radiological evidence of proximal Humeral fractures with three-part or four-part; surgical treatment was performed within twenty-one days after the acute fracture. Consecutive patients with proximal Humeral fractures will be stochastic to be dealt with a locking plate or a bone nail. The informed consent will be acquired in each patients. Two groups will use the same postoperative rehabilitation protocol. Clinical outcomes include Intraoperative blood loss, operation time, Constant-Murley score, Disability, Arm, Shoulder and Hand score, shoulder range of motion (such as external rotation), and postoperative complications. The significance level was defaulted as P Results This study will provide a solid theoretical basis for exploring which technique is better in treatment of 3-part or 4-part proximal Humeral Neck fractures in elderly population. Trial registration This study protocol was registered in Research Registry (number: researchregistry6047).