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Joints and Ligaments - Horse Anatomy (view source)
Revision as of 11:53, 15 October 2012
, 11:53, 15 October 2012Created page with "{{unfinished}} ==Thoracic Limb== ===Shoulder Joint=== The joint capsule attaches a very short distance from the periphery of the articular surfaces. The '''intertubercular (b..."
{{unfinished}}
==Thoracic Limb==
===Shoulder Joint===
The joint capsule attaches a very short distance from the periphery of the articular surfaces. The '''intertubercular (bicipital) bursa''' lies between the humeral tubercles, cushioning the '''bicipital tendon'''. The bursa and tendon are held in place by the '''transverse humeral retinaculum''', running between the greater and lesser tubercles of the humerus.
===Elbow Joint===
The joint capsule attaches to the articular surface of the condyle, the periphery of the olecranon fossa and the articular cartilage of the trochlear notch of the ulna. It fuses with the collateral ligaments. Paired '''collateral ligaments''' attach the epicondyles to the tuberosities of the radius and ulna.
===Carpal Joint===
The carpal joint is a compound joint composed of:
:The '''antebrachiocarpal joint''' between the radius/ulna and the proximal carpal bones
:The '''middle carpal joint''' between the two rows of carpal bones
:The '''carpometacarpal joint''' between the distal carpal bones and the proximal metacarpals
The joint is a synovial joint, comprising a common outer fibrous capsule and three inner synovial pouches, one for each joint. '''Collateral ligaments''' extend from the radius to the metacarpal bones on the medial and lateral aspect of the carpus. The '''carpal canal''' houses both the superficial and deep digital flexor tendon within a common synovial sheath.
====Metacarpophalangeal (Fetlock) Joint====
The fetlock joint allows flexion and extension movements. This joint is associated with a pair of sesamoid bones on the palmar surface. Between the sesamoids in a groove lies articular cartilage which articulates with the sagittal ridge of metacarpal III. The joint capsule runs between all bones in the joint and attaches to the articular cartilage of the sesamoids. It has an extensive pouch under the extensor tendon continuing a quarter the length up the cannon bone. The '''collateral ligaments''' bind the metacarpal bone to the proximal phalanx, with a deep branch attaching to the sesamoid bone. The '''palmar/intersesamoidean ligament''' is a mass of fibrocartilage that embed the sesamoid bones. The palmar aspect of it forms a groove for the deep flexor tendon to run in. The '''collateral sesamoid ligaments''' connect the outer aspect of the sesamoids to the proximal phalanx and there is a distinct branch that attaches to the cannon bone. The '''distal sesamoid ligaments''' are a collection of ligaments that are very marked in the horse and connect the distal surface of the sesamoids to the palmar aspect of the phalanx. These ligaments include the '''short ligaments''', '''cruciate ligaments''', '''oblique ligament''', '''straight ligament''' and the '''palmer annular ligament'''. The '''short ligaments''' connect the axial base of the sesamoids to the lateral/medial aspect on the palmar margin of the proximal phalanx. These are the deepest of the ligaments. The '''cruciate ligaments''' are paired ligaments from the base of the sesamoids that diagonally cross to attach to the proximal phalanx. It lies superficial to the short ligaments. The '''oblique ligament''' is a triangular shaped ligament, the base of which attaches to the sesamoids and their interconnecting ligament and the point attaches to the rough palmar aspect of the proximal phalanx. It is superficial to the cruciates. The '''straight ligament''' proximally attaches like the oblique but attaches as a flat band to the edge of the complementary fibrocartilage of the proximal end of the middle phalanx. Finally, the '''palmar annular ligament''' wraps around the sesamoids, flexor tendons and their associated sheaths.
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====Proximal Interphalangeal (Pastern) Joint====
The pastern joint allows flexion and extension movements. The palmar border of the middle phalanx has a complementary fibrocartilage that extends the proximal articular surface of the middle phalanx. It is sometimes called the middle scutum as it provides a gliding surface for the deep digital flexor. The joint capsule is simple and attaches by the articular margins of the two phalanges. The '''collateral ligaments''' connect the distal end of the proximal phalanx to the proximal end of the middle phalanx. They lie in a vertical direction rather than along the bone axis. The fibres of the '''collateral sesamoid ligaments''' of the distal interphalangeal joint run with it, attach to the middle phalanx and then continue on to their distal attachments. The '''palmar ligaments''' connect the palmar aspect of the distal half of the proximal phalanx to the complementary fibrocartilage of the middle phalanx. A '''proximal digital annular ligament''' wraps around the superficial surface of the flexor tendons and their sheaths at the level of the proximal phalanx. There is a distal one also exists that is attached to the proximal phalanx, it is superficially associated with the digital cushion and is connected to the ergot by the thin fibrous '''ligament of the ergot'''.
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====Distal Interphalangeal (Coffin) Joint====
The coffin joint allows extension and slight flexion movements. The '''navicular bursa''' lies between the navicular bone and the deep flexor tendon. The joint capsule attaches to the articular periphery. There is a dorsal recess under the extensor tendons and a palmar one that runs to about half the height of the middle phalanx. It dips between the distal phalanx and sesamoid and bulges laterally where it is related to the collateral ligaments. The '''collateral ligaments''' connect the distal part of the middle phalanx to the sides of the proximal distal phalanx. The '''distal sesamoid ligaments'''' connect the distal border of the navicular bone to the flexor surface of the distal phalanx. The '''collateral sesamoid ligaments''' are fibroelastic ligaments that attach to the proximal phalanx with the collateral ligaments of the pastern joint and insert to the proximal border of the navicular bone. The ungual/lateral cartilages have a series of ligaments going to the medial/lateral surfaces of the three phalanges and distal sesamoid. There is also a fibrous band connecting the inner surfaces of the cartilages by crossing the superficial aspect of the deep digital flexor tendon.
==Pelvic Limb==
====[[Hindlimb - Anatomy & Physiology#Sacroiliac Joint|Sacroiliac Joint]]====
In horses the short branch of the '''dorsal sacroiliac ligaments''' connects the sacral tuberosity to the spinous processes of the sacrum. The '''sacrotuberous ligament''' is a broad sheet-like ligament, which extends between the transverse processes of the first caudal vertebrae and the dorsal border of ischium and ilium. In this ligament are the '''lesser and greater ischiatic foramen''', these are present to allow for blood vessels, nerves and tendons.
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====[[Hindlimb - Anatomy & Physiology#Coxafemoral|Coxafemoral/Hip Joint]]====
The horse has a limited range of hip movement compared to a dog. This is mainly restricted to flexion and extension and is a result of the conformation of its femoral head, intraarticular ligaments and a large muscle mass around the joint. Unlike other species the horse also has an extra ligament present in the joint; the '''accessory ligament'''.
===[[Hindlimb - Anatomy & Physiology#Stifle Joint|Stifle Joint]]===
The equine stifle has three patellar ligaments:
*'''Middle Patellar Ligament'''
The middle patellar ligament connects the the cranial aspect of the '''[[Hindlimb - Anatomy & Physiology#Patella|patella]]''' apex to the tibial tuberosity. It has two associated bursae; one between the ligament and the groove on the tibial tuberosity and one between the proximal part of the ligament and the patella apex. It is palpable just proximal to the tibial plateau.
*'''Lateral Patellar Ligament'''
The lateral patellar ligament attaches to the cranio-lateral aspect of the '''[[Hindlimb - Anatomy & Physiology#Patella|patella]]''' and to the lateral aspect of the tibial tuberosity. This arrangement is crucial for the equine 'stay' apparatus and provides a '''locking ability'''.
*'''Medial Patellar Ligament'''
The medial patellar ligament connects the parapatellar fibrocartilage to the medial aspect of the tibial tuberosity.
Contraction of the quadriceps while in rest enables the patella to be hooked over the trochlea of the femur due to the binding loop formed by the patella, middle and medial patellar ligaments. The '''femeropatellar joint''' capsule sometimes communicates with the '''lateral femerotibial''' cavity and usually with the '''medial'''. No communication exists between the femorotibial joints.
[[Category:Horse Anatomy]]
==Thoracic Limb==
===Shoulder Joint===
The joint capsule attaches a very short distance from the periphery of the articular surfaces. The '''intertubercular (bicipital) bursa''' lies between the humeral tubercles, cushioning the '''bicipital tendon'''. The bursa and tendon are held in place by the '''transverse humeral retinaculum''', running between the greater and lesser tubercles of the humerus.
===Elbow Joint===
The joint capsule attaches to the articular surface of the condyle, the periphery of the olecranon fossa and the articular cartilage of the trochlear notch of the ulna. It fuses with the collateral ligaments. Paired '''collateral ligaments''' attach the epicondyles to the tuberosities of the radius and ulna.
===Carpal Joint===
The carpal joint is a compound joint composed of:
:The '''antebrachiocarpal joint''' between the radius/ulna and the proximal carpal bones
:The '''middle carpal joint''' between the two rows of carpal bones
:The '''carpometacarpal joint''' between the distal carpal bones and the proximal metacarpals
The joint is a synovial joint, comprising a common outer fibrous capsule and three inner synovial pouches, one for each joint. '''Collateral ligaments''' extend from the radius to the metacarpal bones on the medial and lateral aspect of the carpus. The '''carpal canal''' houses both the superficial and deep digital flexor tendon within a common synovial sheath.
====Metacarpophalangeal (Fetlock) Joint====
The fetlock joint allows flexion and extension movements. This joint is associated with a pair of sesamoid bones on the palmar surface. Between the sesamoids in a groove lies articular cartilage which articulates with the sagittal ridge of metacarpal III. The joint capsule runs between all bones in the joint and attaches to the articular cartilage of the sesamoids. It has an extensive pouch under the extensor tendon continuing a quarter the length up the cannon bone. The '''collateral ligaments''' bind the metacarpal bone to the proximal phalanx, with a deep branch attaching to the sesamoid bone. The '''palmar/intersesamoidean ligament''' is a mass of fibrocartilage that embed the sesamoid bones. The palmar aspect of it forms a groove for the deep flexor tendon to run in. The '''collateral sesamoid ligaments''' connect the outer aspect of the sesamoids to the proximal phalanx and there is a distinct branch that attaches to the cannon bone. The '''distal sesamoid ligaments''' are a collection of ligaments that are very marked in the horse and connect the distal surface of the sesamoids to the palmar aspect of the phalanx. These ligaments include the '''short ligaments''', '''cruciate ligaments''', '''oblique ligament''', '''straight ligament''' and the '''palmer annular ligament'''. The '''short ligaments''' connect the axial base of the sesamoids to the lateral/medial aspect on the palmar margin of the proximal phalanx. These are the deepest of the ligaments. The '''cruciate ligaments''' are paired ligaments from the base of the sesamoids that diagonally cross to attach to the proximal phalanx. It lies superficial to the short ligaments. The '''oblique ligament''' is a triangular shaped ligament, the base of which attaches to the sesamoids and their interconnecting ligament and the point attaches to the rough palmar aspect of the proximal phalanx. It is superficial to the cruciates. The '''straight ligament''' proximally attaches like the oblique but attaches as a flat band to the edge of the complementary fibrocartilage of the proximal end of the middle phalanx. Finally, the '''palmar annular ligament''' wraps around the sesamoids, flexor tendons and their associated sheaths.
<br />
<br />
====Proximal Interphalangeal (Pastern) Joint====
The pastern joint allows flexion and extension movements. The palmar border of the middle phalanx has a complementary fibrocartilage that extends the proximal articular surface of the middle phalanx. It is sometimes called the middle scutum as it provides a gliding surface for the deep digital flexor. The joint capsule is simple and attaches by the articular margins of the two phalanges. The '''collateral ligaments''' connect the distal end of the proximal phalanx to the proximal end of the middle phalanx. They lie in a vertical direction rather than along the bone axis. The fibres of the '''collateral sesamoid ligaments''' of the distal interphalangeal joint run with it, attach to the middle phalanx and then continue on to their distal attachments. The '''palmar ligaments''' connect the palmar aspect of the distal half of the proximal phalanx to the complementary fibrocartilage of the middle phalanx. A '''proximal digital annular ligament''' wraps around the superficial surface of the flexor tendons and their sheaths at the level of the proximal phalanx. There is a distal one also exists that is attached to the proximal phalanx, it is superficially associated with the digital cushion and is connected to the ergot by the thin fibrous '''ligament of the ergot'''.
<br />
<br />
====Distal Interphalangeal (Coffin) Joint====
The coffin joint allows extension and slight flexion movements. The '''navicular bursa''' lies between the navicular bone and the deep flexor tendon. The joint capsule attaches to the articular periphery. There is a dorsal recess under the extensor tendons and a palmar one that runs to about half the height of the middle phalanx. It dips between the distal phalanx and sesamoid and bulges laterally where it is related to the collateral ligaments. The '''collateral ligaments''' connect the distal part of the middle phalanx to the sides of the proximal distal phalanx. The '''distal sesamoid ligaments'''' connect the distal border of the navicular bone to the flexor surface of the distal phalanx. The '''collateral sesamoid ligaments''' are fibroelastic ligaments that attach to the proximal phalanx with the collateral ligaments of the pastern joint and insert to the proximal border of the navicular bone. The ungual/lateral cartilages have a series of ligaments going to the medial/lateral surfaces of the three phalanges and distal sesamoid. There is also a fibrous band connecting the inner surfaces of the cartilages by crossing the superficial aspect of the deep digital flexor tendon.
==Pelvic Limb==
====[[Hindlimb - Anatomy & Physiology#Sacroiliac Joint|Sacroiliac Joint]]====
In horses the short branch of the '''dorsal sacroiliac ligaments''' connects the sacral tuberosity to the spinous processes of the sacrum. The '''sacrotuberous ligament''' is a broad sheet-like ligament, which extends between the transverse processes of the first caudal vertebrae and the dorsal border of ischium and ilium. In this ligament are the '''lesser and greater ischiatic foramen''', these are present to allow for blood vessels, nerves and tendons.
<br />
<br />
====[[Hindlimb - Anatomy & Physiology#Coxafemoral|Coxafemoral/Hip Joint]]====
The horse has a limited range of hip movement compared to a dog. This is mainly restricted to flexion and extension and is a result of the conformation of its femoral head, intraarticular ligaments and a large muscle mass around the joint. Unlike other species the horse also has an extra ligament present in the joint; the '''accessory ligament'''.
===[[Hindlimb - Anatomy & Physiology#Stifle Joint|Stifle Joint]]===
The equine stifle has three patellar ligaments:
*'''Middle Patellar Ligament'''
The middle patellar ligament connects the the cranial aspect of the '''[[Hindlimb - Anatomy & Physiology#Patella|patella]]''' apex to the tibial tuberosity. It has two associated bursae; one between the ligament and the groove on the tibial tuberosity and one between the proximal part of the ligament and the patella apex. It is palpable just proximal to the tibial plateau.
*'''Lateral Patellar Ligament'''
The lateral patellar ligament attaches to the cranio-lateral aspect of the '''[[Hindlimb - Anatomy & Physiology#Patella|patella]]''' and to the lateral aspect of the tibial tuberosity. This arrangement is crucial for the equine 'stay' apparatus and provides a '''locking ability'''.
*'''Medial Patellar Ligament'''
The medial patellar ligament connects the parapatellar fibrocartilage to the medial aspect of the tibial tuberosity.
Contraction of the quadriceps while in rest enables the patella to be hooked over the trochlea of the femur due to the binding loop formed by the patella, middle and medial patellar ligaments. The '''femeropatellar joint''' capsule sometimes communicates with the '''lateral femerotibial''' cavity and usually with the '''medial'''. No communication exists between the femorotibial joints.
[[Category:Horse Anatomy]]