Distribution of Subchondral Bone Puncture Strength in the Talus and Tibial Plafond: A Biomechanical Study

2017 ◽  
Vol 11 (1) ◽  
pp. 44-48
Author(s):  
Slif D. Ulrich ◽  
Brent G. Parks ◽  
Michael A. Tsai ◽  
Stuart D. Miller
Keyword(s):  
Subchondral Bone ◽  
Articular Surface ◽  
Compressive Load ◽  
Biomechanical Study ◽  
Anatomy And Physiology ◽  
Tibial Plafond ◽  
Complex Anatomy ◽  
Lateral Zone ◽  
Surface Location ◽  
Puncture Strength

We investigated talus and tibial plafond subchondral bone puncture strength based on surface location. Puncture tests of the subchondral bone were performed in 9 equal zones on the articular surface of 12 cadaver specimens aged 49.1 years (range, 36-56 years). Compressive load was applied through a microfracture awl at 2 mm/min. Puncture strength was defined as the first load drop in load-deflection curves. In the talus, zone 1 (215 ± 91 N) and zone 2, the anterior medial and anterior middle zones, had significantly greater puncture strength than zones 7, 8, and 9, the posterior medial, middle, and lateral zones (104 ± 43 N, 115 ± 43 N, and 102 ± 35 N, respectively; P < .001). In the tibial plafond, zone 3, the anterior-lateral zone, and zone 7, the posterior medial zone, had significantly greater strength than zone 8, the posterior middle zone (202 ± 72 N, 206 ± 121 N, and 112 ± 65 N, respectively; P < .001) These results suggest that the subchondral bone is significantly weaker to penetrative force in the posterior region than in the anterior region of the talar dome and of the tibial plafond. These findings may have implications for microfracture awl design and for understanding the complex anatomy and physiology of the ankle joint. Levels of Evidence: Controlled laboratory study

Radiographic Prevalence of Osteochondrosis in Yearling Feral Horses

1999 ◽  
Vol 12 (03) ◽  
pp. 151-155 ◽  
Author(s):  
L. W. Valentino ◽  
E. M. Gaughan ◽  
D. R. Biller ◽  
R. H. Raub ◽  
J. D. Lillich
Keyword(s):  
Subchondral Bone ◽  
Management Practices ◽  
Articular Surface ◽  
Radiographic Images ◽  
Feral Horses ◽  
Metacarpophalangeal Joints ◽  
Genetic Base ◽  
Domestic Horses ◽  
The Difference ◽  
Metatarsophalangeal Joints

The purpose of the study is to document the prevalence of articular surface osteochondrosis lesions in feral horses. Eighty yearling feral horses were used. Radiographic images of the left stifle, both tarsocrural, metatarsophalangeal, metacarpophalangeal joints were taken. Radiographs were examined for the presence of osteochondral fragmentation and abnormal outline of subchondral bone suggestive of osteochondrosis. The prevalence of each lesion was calculated for each joint as well as for overall prevalence within the group, the latter being 6.25%. Typical osteochondrosis lesions were found within the tarsocrural and metatarsophalangeal joints. Based on the difference in prevalence of osteochondrosis between feral and certain domestic horses, management practices and perhaps genetic base may have a greater influence on the development of the disease in horses than trauma alone.

scholarly journals Free flap for soft palate reconstruction: long-term functional evaluation of a new technique

2021 ◽  
Author(s):  
A. Colliard ◽  
L. Pincet ◽  
C. Simon ◽  
L. May ◽  
K. Lambercy
Keyword(s):  
Soft Palate ◽  
Free Flap ◽  
New Technique ◽  
Tumour Resection ◽  
Functional Evaluation ◽  
Anatomy And Physiology ◽  
Complex Anatomy ◽  
A New Technique ◽  
Anderson Dysphagia Inventory ◽  
Nasal Regurgitation

Abstract Purpose The soft palate (SP) has a complex anatomy and physiology. Reconstruction after tumour resection is a challenge, and procedures that only restore bulk don’t give good results. We aim to present a new technique for the in-setting and the functional outcomes. Methods We retrospectively included in a monocentric retrospective cohort study every patient with a first diagnosis of a soft palate squamous cell carcinoma (SPSCC), who underwent a tumoral resection with a free flap reconstruction, from February 2013 to July 2017. For the in-setting, a special care is given for the flap in-setting: we suture the flap more caudally than usual under the tongue base, creating a neo-posterior pilar. The primary outcome was the deglutition function, assessed by the M. D Anderson Dysphagia Inventory (MDADI). We also analyzed the patient’s quality of life with the FOSS score and the occurrence of nasal regurgitation or larynx aspiration. Results We included twenty patients, with a median follow-up of 26.5 months. The median MDADI score was 89, and the mode was 93. A Fisher test shows a significant improvement of MDADI scores for unilateral vs bilateral reconstructions (p = 0.03). The median FOSS score was 2, and the mode was 2. Seven (35%) patients complained of nasal regurgitation, three (15%) reported episodic laryngeal aspiration.

scholarly journals Tissue Modification of the Lateral Compartment of the Tibio-Femoral Joint Following In Vivo Varus Loading in the Rat

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
M. L. Roemhildt ◽  
B. D. Beynnon ◽  
M. Gardner-Morse ◽  
K. Anderson ◽  
G. J. Badger
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Compressive Loading ◽  
Compressive Load ◽  
Lateral Compartment ◽  
Peripheral Region ◽  
Degenerative Changes ◽  
Medial Compartment ◽  
Compressive Loads

This study describes the first application of a varus loading device (VLD) to the rat hind limb to study the role of sustained altered compressive loading and its relationship to the initiation of degenerative changes to the tibio-femoral joint. The VLD applies decreased compressive load to the lateral compartment and increased compressive load to the medial compartment of the tibio-femoral joint in a controlled manner. Mature rats were randomized into one of three groups: unoperated control, 0% (sham), or 80% body weight (BW). Devices were attached to an animal’s leg to deliver altered loads of 0% and 80% BW to the experimental knee for 12 weeks. Compartment-specific material properties of the tibial cartilage and subchondral bone were determined using indentation tests. Articular cartilage, calcified cartilage, and subchondral bone thicknesses, articular cartilage cellularity, and degeneration score were determined histologically. Joint tissues were sensitive to 12 weeks of decreased compressive loading in the lateral compartment with articular cartilage thickness decreased in the peripheral region, subchondral bone thickness increased, and cellularity of the midline region decreased in the 80% BW group as compared to the 0% BW group. The medial compartment revealed trends for diminished cellularity and aggregate modulus with increased loading. The rat-VLD model provides a new system to evaluate altered quantified levels of chronic in vivo loading without disruption of the joint capsule while maintaining full use of the knee. These results reveal a greater sensitivity of tissue parameters to decreased loading versus increased loading of 80% BW for 12 weeks in the rat. This model will allow future mechanistic studies that focus on the initiation and progression of degenerative changes with increased exposure in both magnitude and time to altered compressive loads.

scholarly journals Subchondral bone morphology in the metacarpus of racehorses in training changes with distance from the articular surface but not with age

2018 ◽  
Vol 232 (6) ◽  
pp. 919-930 ◽  
Author(s):  
Sandra Martig ◽  
Peta L. Hitchens ◽  
Mark A. Stevenson ◽  
R. Chris Whitton
Keyword(s):  
Subchondral Bone ◽  
Articular Surface ◽  
Bone Morphology

scholarly journals Drug Delivery to the Posterior Segment of the Eye: Biopharmaceutic and Pharmacokinetic Considerations

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 269 ◽  
Author(s):  
Rubén Varela-Fernández ◽  
Victoria Díaz-Tomé ◽  
Andrea Luaces-Rodríguez ◽  
Andrea Conde-Penedo ◽  
Xurxo García-Otero ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Posterior Segment ◽  
Anatomy And Physiology ◽  
Administration Routes ◽  
Age Related ◽  
Complex Anatomy ◽  
Site Of Action ◽  
Intraocular Drug Delivery ◽  
Novel Drug ◽  
Drug Pharmacokinetics

The treatment of the posterior-segment ocular diseases, such as age-related eye diseases (AMD) or diabetic retinopathy (DR), present a challenge for ophthalmologists due to the complex anatomy and physiology of the eye. This specialized organ is composed of various static and dynamic barriers that restrict drug delivery into the target site of action. Despite numerous efforts, effective intraocular drug delivery remains unresolved and, therefore, it is highly desirable to improve the current treatments of diseases affecting the posterior cavity. This review article gives an overview of pharmacokinetic and biopharmaceutics aspects for the most commonly-used ocular administration routes (intravitreal, topical, systemic, and periocular), including information of the absorption, distribution, and elimination, as well as the benefits and limitations of each one. This article also encompasses different conventional and novel drug delivery systems designed and developed to improve drug pharmacokinetics intended for the posterior ocular segment treatment.

scholarly journals Stress Distribution Patterns Across the Shoulder Joint in Gymnasts: A Computed Tomography Osteoabsorptiometry Study

2020 ◽  
Vol 8 (11) ◽  
pp. 232596712096210
Author(s):  
Daisuke Momma ◽  
Wataru Iwamoto ◽  
Kaori Endo ◽  
Kazuki Sato ◽  
Norimasa Iwasaki
Keyword(s):  
Bone Density ◽  
Stress Distribution ◽  
Distribution Pattern ◽  
Subchondral Bone ◽  
Shoulder Joint ◽  
Glenohumeral Joint ◽  
Articular Surface ◽  
Articular Surfaces ◽  
Subchondral Bone Density ◽  
Collegiate Gymnasts

Background: The distribution pattern of subchondral bone density is an indicator of stress distribution over a joint surface under long-term physiologic loading. The biomechanical characteristics of the articular surfaces of the shoulder joint in gymnasts can be determined by measuring this distribution pattern. Purpose: To evaluate the distribution of subchondral bone density across the shoulder joint in male collegiate gymnasts and to determine the effects of gymnastic activities on its articular surfaces under long-term loading conditions using computed tomography osteoabsorptiometry (CTOAM). Study Design: Descriptive laboratory study. Methods: CT image data were obtained from both shoulders of 12 asymptomatic male collegiate gymnasts (gymnast group; mean age, 19.4 years; range, 18-22 years) and 10 male collegiate volunteers (control group; mean age, 20.2 years; range, 18-22 years). The distribution pattern of subchondral bone density across the articular surfaces of each shoulder joint was assessed by CTOAM. Quantitative analysis was performed of the locations and percentages of high-density areas on the articular surface. Results: Stress distribution patterns over the articular surfaces differed between the gymnasts and the controls. In the gymnasts, high-density areas were detected on the posterosuperior articular surface of the humeral head and the anterosuperior and/or posterosuperior articular surface of the glenoid. Mean bone density was greater in the gymnasts than in the controls ( P < .0001). Conclusion: Stress distribution over the articular surfaces of the shoulder joint was affected by gymnastic activities. Stress was concentrated over the superior part of the glenohumeral joint in male collegiate gymnasts. Clinical Relevance: The present findings suggest that gymnastic activities increase stress to the articular surfaces of the superior glenohumeral joint. This supports the notion that mechanical conditions play a crucial role in the origin of disorders particular to gymnastic activities.

Are Variable-Angle Locking Screws Stable Enough to Prevent Calcaneal Articular Surface Collapse? A Biomechanical Study

2018 ◽  
Vol 32 (6) ◽  
pp. e204-e209 ◽  
Author(s):  
Martin C. Jordan ◽  
Konrad Fuchs ◽  
Timo M. Heintel ◽  
Hendrik Jansen ◽  
Stefanie Hoelscher-Doht ◽  
...  
Keyword(s):  
Articular Surface ◽  
Biomechanical Study ◽  
Locking Screws ◽  
Variable Angle ◽  
Surface Collapse

scholarly journals Long-term Stress Distribution Patterns Across the Ankle Joint in Soccer Players: A Computed Tomography Osteoabsorptiometry Study

2020 ◽  
Vol 8 (11) ◽  
pp. 232596712096308
Author(s):  
Junki Shiota ◽  
Daisuke Momma ◽  
Takayoshi Yamaguchi ◽  
Norimasa Iwasaki
Keyword(s):  
Bone Density ◽  
Stress Distribution ◽  
Ankle Joint ◽  
Subchondral Bone ◽  
Articular Surface ◽  
Distribution Patterns ◽  
High Density ◽  
Soccer Players ◽  
Subchondral Bone Density

Background: The distribution pattern of subchondral bone density is considered to accurately reflect the stress distribution over a joint under long-term physiologic loading. The biomechanical characteristics of the surface of the ankle joint in soccer players can be determined by measuring this distribution pattern under long-term loading. Purpose: To evaluate the distribution of subchondral bone density across the ankle joint in soccer players and to determine the effects of soccer activities, including kicking motion, on the ankle joint surface under long-term loading conditions by computed tomography (CT) osteoabsorptiometry (CTOAM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: CT imaging data were obtained from both ankles of 10 soccer players (soccer group) and 10 nonathletic volunteers (control group). The distribution patterns of subchondral bone density across the articular surface of the ankle joints were assessed by CTOAM. Quantitative analysis was performed of the locations and percentages of high-density areas on the articular surface. Results: Stress distribution patterns over the ankle joint differed between the soccer players and controls. In the soccer players, the high-density areas were found in the anterior part of the distal tibia and proximal talus as well as the distal fibula. The percentages of high-density areas were greater in the soccer players compared with controls ( P < .0001). Conclusion: Stress distribution over the articular surface of the ankle joint was affected by soccer activities. A high stress concentration was seen in soccer players in the anterior part of the tibia and talus and in the fibula; such excessive stress may lead to anterior impingement.

scholarly journals Acetabular Subchondral and Cortical Breach During Labral Repair with Suture Anchors: Influence of Portal Location, Curved vs Straight Drill Guides, and Drill Starting Point

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0037
Author(s):  
Guillaume D. Dumont ◽  
Adam Money ◽  
Zachary Thier
Keyword(s):  
Subchondral Bone ◽  
Articular Surface ◽  
Labral Repair ◽  
Relative Impact ◽  
Suture Anchors ◽  
Drill Guide ◽  
Labral Tears ◽  
Starting Point ◽  
Drill Holes ◽  
Acetabular Rim

Objectives: Acetabular labral tears are commonly treated with arthroscopic repair using suture anchors. Iatrogenic chondral injury has been cited as one of the more common complications during hip arthroscopy, and can occur while pre-drilling for suture anchors. Proposed factors contributing to penetration of the articular subchondral bone or the far cortex of the acetabulum include the portal utilized for drilling; the position of the drill guide relative to the acetabular rim (on rim, ON; off rim, OFF); and the use of straight (ST) versus curved (CU) drill guides. The purpose of this study was to evaluate the relative impact of these variables on drill penetration of the acetabular subchondral bone or the far cortex of the acetabulum. Methods: Sixty sawbone acetabula models were marked at the 3, 2, 1, 12, and 11 o’clock position. A Simulated anterior (AP), anterolateral (AL), and distal anterolateral accessory (DALA) portals were created. Twelve groups of five acetabula were drilled at each clock face position: ST/AP/ON; ST/AL/ON; CU/AP/ON; CU/AL/ON; ST/AP/OFF; ST/AL/OFF; CU/AP/OFF; CU/AL/OFF; ST/DALA/ON; ST/DALA/OFF; CU/DALA/ON; CU DALA/OFF. Perforations of the articular subchondral bone and far cortex of the acetabulum were recorded. Results were tabulated and analyzed to assess the relative impact of each variable both in aggregate and at each position on the clock face. Results: A total of 300 acetabular suture anchor drill holes were created on 60 acetabula 12 combinations of portal utilized (anterior, anterolateral, distal anterolateral accessory), drill guide type (curved or straight), and rim position (on rim, off rim). A total of 38/300(12.7%) drillings perforated the subchondral bone, and 45/300(15%) breach the far cortex. Drilling from the AP, AL, and DALA portal breached the articular subchondral bone 21/100 (21%), 17/100(17%), and 0/100(0%) respectively; and breached the far acetabular cortex 36/100(36%), 1/100(1%), and 8/100(8%) respectively. Drillings using a curved drill guide penetrated the subchondral bone on 14/150(9.3%) attempts and drillings using a straight drill guide penetrated the subchondral bone 33/150(22%) attempts (p=0.0025). Drillings with an “On Rim” start point breached the articular subchondral bone 29/150(19.3%) versus 9/150(6%) for drillings with an “Off Rim” start point; and breached the far acetabular cortex 21/150(14%) times versus 24/150(16%) times. Articular surface penetrations were most frequent at the 2 and 3 o’clock positons, and far cortex perforations were most frequent at the 11 and 12 o’clock positions. Conclusion: This study quantifies the relative impact of portal location, drill guide, and starting point on the acetabular rim on acetabular subchondral bone and far cortex penetration. Portal location had the highest impact, with the DALA portal noted to be the safest. Curved drill guides also reduced the number of acetabular subchondral bone penetrations. These findings can be used to influence arthroscopic technique during acetabular labral repair.

The Amygdaloid Complex: Anatomy and Physiology

2003 ◽  
Vol 83 (3) ◽  
pp. 803-834 ◽  
Author(s):  
P. SAH ◽  
E. S. L. FABER ◽  
M. LOPEZ DE ARMENTIA ◽  
J. POWER
Keyword(s):  
Synaptic Plasticity ◽  
Sensory Information ◽  
Amygdaloid Complex ◽  
In Vivo Studies ◽  
Anatomy And Physiology ◽  
Efferent Connections ◽  
Complex Anatomy ◽  
Subcortical Regions

Sah, P., E. S. L. Faber, M. Lopez de Armentia, and J. Power. The Amygdaloid Complex: Anatomy and Physiology. Physiol Rev 83: 803–834, 2003; 10.1152/physrev.00002.2003.—A converging body of literature over the last 50 years has implicated the amygdala in assigning emotional significance or value to sensory information. In particular, the amygdala has been shown to be an essential component of the circuitry underlying fear-related responses. Disorders in the processing of fear-related information are likely to be the underlying cause of some anxiety disorders in humans such as posttraumatic stress. The amygdaloid complex is a group of more than 10 nuclei that are located in the midtemporal lobe. These nuclei can be distinguished both on cytoarchitectonic and connectional grounds. Anatomical tract tracing studies have shown that these nuclei have extensive intranuclear and internuclear connections. The afferent and efferent connections of the amygdala have also been mapped in detail, showing that the amygdaloid complex has extensive connections with cortical and subcortical regions. Analysis of fear conditioning in rats has suggested that long-term synaptic plasticity of inputs to the amygdala underlies the acquisition and perhaps storage of the fear memory. In agreement with this proposal, synaptic plasticity has been demonstrated at synapses in the amygdala in both in vitro and in vivo studies. In this review, we examine the anatomical and physiological substrates proposed to underlie amygdala function.

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