Anatomy: Self Study: bones and joints
What two ligaments support the AC joint?
-acromioclavicular AC -coracoclavicular
What is the talocrural joint?
-ankle -hinge joint: dorsiflexion and plantarflexion -tendons play a major role in maintaining stability
What is the role of arches of the foot?
-arches of foot are important in distributing weight and absorbing the shock that occurs iwht locomotion
What 3 characteristics do all synovial joints have?
-articular (synovial) capsule: 2 parts, outer fibrous layer and inner synovial membrane that secretes synovial flu9id -articular (synovial) cavity: synovial fluid lines majority of the cavity -articular cartilage (hyaline): mostly avascular and slow/ does not heal
What is circumduction?
-circular motion -combined: flexion, abduction, extension, adduction
What is the radiocarpal joint and associated ligaments?
-condyloid joint -distal end of radius and proximal row of carpals (excluding pisiform) - ulna does not directly articular in the wrist joint (articular disc) -very closely associated w distal radio ulnar joint -ulnar (medial support) and radial (lateral support) collateral ligaments -palmar radiocarpal ligament: limits wrist extension -dorsal radiocarpal ligament: limits wrist flexion
What is the FCL?
-extracpsular -checks hyperextension and relaxed in flexion -separated from articular capsule by the popliuteus m tendon
What ligaments are associated w the knee joint?
-fibrular (lateral) collateral ligament (FCL) -tibial (medial) collateral ligament (TCL) -anterior cruciate ligament (ACL) -posterior cruciate ligament (PCL) -menisci
Plane joint:
-gliding/ sliding -acromioclavicular joint, proximal radio-ulnar
What are the 6 major types of synovial joints?
-hinge, plane, pivot, saddle, condyloid, ball & socket
What is the ileofemoral ligament?
-hip joint -strongest and most expansive ligament -ilium to femur, Y shaped -prevents hyperextension and limits abduction and lateral rotation
What are the major joints of the ebow/ forearm region?
-humero ulnar (elbow) joints: hinge -humeroradial joint: hinge -proximal radio-ulnar joint: pivot joint (supination, pronation) -radio-ulnar syndesmosis -distal radio ulnar joint: pivot
What ligaments are associated w the hip joint?
-ileofemoral -pubofemoral -ischiofemoral -ligament of head of femur -transverse acetabular ligament
How do we define medial and lateral rotation?
-medial: brings the anterior surface closed to median plane -lateral: takes anterior surface away from the median plane
What is the knee joint?
-modified hinge joint (slight medial and lateral rotation) -composed of 3 articulations: medial and lateral tibiofemoral joints nad patellofemoral joints -relatively weak mechanically, incongruence of articular surfaces
What is the clinical importance of the medial longitudinal arch?
-most affected in flatfeet/ fallen arches
What is the deltoid (medial) ligament?
-of talocrural ankle joint -all parts have attachment ot medial malleolus and become intertwined, stabilizes joint during eversion -much stronger than lateral counterparts
What are the lateral ligaments (antior and posterior talofibular and calcaneofibular ligaments)?
-of talocrural ankle joint -all parts have attachment to lateral malleolus but do not intertwine -stabilizes joint during inversion→ injuries occur more commonly on this side, may be damaged by forcibly inverting the foot
What is the distal radio ulnar joint?
-pivot (pronation and supination) -elbow/ forearm region
What is the AC joint? (shoulder region)
-plane joint (gliding/ sliding of scapula on the clavical) -clinical importance: disruption= shoulder separation -AC ligament: acromion to lateral clavicle- strengthens superiorly -coracoclavicular ligament: strongest of AC joint, severe shoulder separations include tearing of this ligament
Pivot joint:
-rotiation -atlanto-axial, proximal radioulnar
What is the clinical importance of the glenohumeral shoulder joint?
-shoulder dislocation here -most dislocations occur inferiorly, due to a weak point in musculotendinous rotator cuff -main source of stability= rotator cuff muscles and tendons
What are cartilaginous joints?
-strong, slightly moveable -surfaces of articulating bones are covered with hyaline cartilage and bones are united by strong fibrous tissue and or fibrocartilage -ex: epiphyseal growth plates, intervertebral discs, pubic symphysis, manubriosternal joint
What are the major joints of the ankle/ foot region?
-talocrural -subtalar and transverse tarsal joints: inversion eversion
What forms the medial longitudinal arch?
-trasals except bucoid and 1st-3rd metatarsals -it's the higher of 2 longtidunal arches -head of talus= important component
What are the ligaments of the humero ulnar joint?
-ulnar and radial collateral ligaments: thickenings of fibrous layer of articular capsule -ulnar provides most stability -prevents excessive medial or lateral movements
What are fibrous joints?
-united by fibrous tissue -movement depends on length of fibers uniting the bones -examples: sutures, syndesmosis, gomphosis
Where is the humeroradial joint?
-within articular capsule of the elbow joint
A "pulled elbow" in a young child results when the radial head is dislodged from the:
Annular ligament The definition of the pulled elbow is that the head of the radius is pulled out of the annular ligament and is no longer attached to the ulna.
An example of a temporary cartilaginous joint is a/an:
Epiphyseal plate or growth plate An epiphyseal plate is an example of a synchondrosis, which is a temporary cartilaginous joint present in growing bones.
The interosseous membrane between the radius and ulna is the uniting structure in a type of fibrous joint classified as a:
Syndesmosis A syndesmosis is a fibrous membrane or ligament that joins two bones. The connections between the shafts of the radius and ulna and the tibia and fibula are 2 classical examples of syndesmoses.
How much movement occurs in sutures? Syndesmosis.? Gomphosis?
These are all fibrous joints -sutures: little movement -syndesmosis: degree of movement depends on distance between the bones (ex: interosseous membrane) -gomphosis: unique joint between tooth and bone
What direction is the shoulder most often dislocated in?
anterior, shoulder is covered by muscles of rotator cuff: subscapularis inserts on lesser tubercle of humerus supraspinatus, infraspinatus and teres minor insert on greater tubercle of humerus
If you tist your ankle and foot is forcibly everted, what ligament can be sprained?
deltoid connects medial malleolus w talus, navicular, and calcaneus role is to prevent ankle from dislocating when forcibly everted
What is the glenoid labrum?
fibrocartilaginous structure which deepens the shoulder socket glenoid cavity of scapula= site where head of humerus articulates cavity is depeended by glenoid laabrum, which is a ring of fibrocartilage around glenoid cavity
What ligament normally supports head of talus and is responsible for holding up medial longitudinal arch of the foot?
plantar calcaneonavicular (spring) connects sustentaculum tali w plantar surface of navicular bone, provides majro support for medial longitduinal arch of the foot
An injury or tear to the MCL can result in tearing of...
the medial meniscus
What is the transverse acetabular ligament?
completes the rim of acetabulum
n comparing the symmetry of his two shoulders, you notice a marked elevation of the distal end of his clavicle with respect to the acromion on the injured side. X-ray exam reveals a grade III shoulder separation. In order for this to have occurred, which ligament must be torn?
coracoclavicular ligament A shoulder separation is an injury to the acromioclavicular joint. A first degree separation involves stretching the ligaments, but maintenance of the joint. A second degree separation involves tearing of the joint capsule and coracoclavicular ligament, but still continuity.
What kind of joint is the hip joint? What maintains its structural integrity?
-ball and socket: more stability than gleno humeral joint, closer articulation between bones -medial and lateral rotators of thigh play an important role in maintaining structural integrity of hip joint
What is the glenohumeral shoulder joint?
-ball and socket: most mobile joint of body and least stable -head of humerus and glenoid cavity of the scapula -coraco acromial ligament and transverse humeral ligament
What are menisci?
-fibrocartilaginous -deepends articular surfaces and plays a role in shcok absorption -medial meniscus: less mobile, attached to TCL -lateral meniscus
Hinge joint:
-flexion/ extension -elbow, knee, interphalangeal
Saddle joint:
-flexion/ extension, ab/adduction, circumduction -concave and convex where bones articulate -carpometacarpal joint of the thumb
Ball and socket joint:
-flexion/ extension, ab/adduction, circumduction, medial and lateral rotation -shoulder, hip
Condyloid joint:
-flexion/ extension, abduction/ adduction, circumduction -metacarpophalageal joints of digits 2-5, radiocarpal (wruist)
What are flexion? Extension? Hyperextension?
-flexion: decrease in angle (typically anterior, except knee) -extension: back to anatomical position -hyperextension: past anatomical position
What are the types of movement that occur at synovial joints?
-flexions/ extension/ hyperextension: sagittal plane -abduction/ adduction -circumduction -medial (internal) rotation/ lateral (external) rotation: rotation of a part of the body around its longitudinal axis
What is the transverse arch of the foot?
-formed by cuboid, all cuneiforms, and bases of metacarpals -tendons of tibialis posterior and fibularius longus support this arch
What is the clinical importance of knee joints (unhappy/ terrible triad)?
-injury to ACL/ TCL/ and medial meniscus -excessive lateral twisting to flexed knee or a blow to lateral side of an extended knee
What is the radio ulnar syndesmosis?
-intermediate radio ulnar joint, connects bodies of radius and ulna -inerosseous membrane of forearm
What is the ligament of the head of femor?
-intracapsular -extends from acetabular notch to foveo of femoral head -debate for function -artery of head of femur located inside the ligament, which supplies the head of femur→ if damaged can lead to necrosis of head of femur
What is the ischiofemoral ligament?
-ischium to femur -limits medial rotation and hyperextension
What is important in the structural integrity of the knee joint?
-muscles more important than ligaments -most injuries are preventable through muscle conditioning -quadriceps femoris m, particular vastus medialis and lateralis -semimembranous and popliteus mm play important roles as well
What is the anular ligament?
-of the pxoimal radio ulnar joint -surrounds radial head and attaches to the radial notch of ulna -clinical importance: sublaxation of radial head "pulled elbow" -radial head pulled inferiorly out of angular ligament, most common in juveniles -radial head is comparatively small (mostly cartilage, not ossififed) in relation to size of anular ligament
What are the ligaments of the medial longitudinal arch?
-plantar calcaneonavicular spring ligament: supports the head of the talus, sustentaculum tali of calcneous to navicular -long plantar: calcaneous to cuboid -plantar calcaneocuboid short ligament: between spring and long plantar ligaments -leg muscle tendons also play an active role in supporting this arch
What is the PCL?
-prevents posterior displacement of tibia on femur -if ruptured and posterior displacement allowed: posterior drawer sign
What is the pubofemoral ligament?
-pubis to femur, intertwines with iliofemoral ligament -limits abduction
How do we classify joints?
-structure: fibrous, cartilaginous, synovial
What are the coraco acromial and transverse humeral ligaments?
-support glenuhumeral shoulder joint -coraco: forms arch over shoulder joint region, prevents superior dislocation -transverse humeral: connects greater and lesser tubercles, forms tunnel for tend of biceps brachii m, long head
What are synovial joints?
-synoval membrane encloses articulating surfaces within a joint cavity, cavity has synovial fluid -free movement between bones are typical of nearly all limb joints
What is the ACL?
-weaker han PCL and more commonly injured -prevents anterior displacement of tibia on femur: if ruptured and anterior displacement allowed: anterior draw sign -attached to TCL
What is the TCL?
-weaker than FCL and more commonly injured -prevents lateral bending: limits extension, hyperflexion and lateral rotation -deep fibers of ligaments are attached to medial meniscus
It was determined that a football player tore his coracoclavicular ligament. This is an example of a:
A shoulder separation is the dislocation of the acromioclavicular joint. The injury often occurs from a hard fall on the shoulder with the impact taken by the acromion or from a fall on the outstretched upper limb.
What gives the shoulder joint its greatest strength and stability?
Although the acromioclavicular joint is weak, the coracoclavicular ligament is very strong.
An athlete has a knee injury, and the doctor performs a "drawer test" by pulling and pushing on the leg with the knee flexed. If the leg translates anteriorly, i. e. "gives" or moves anteriorly when the leg is pulled anteriorly, what joint structure is most likely injured?
Anterior cruciate ligament The drawer test is designed to test the integrity of the anterior and posterior cruciate ligaments. It involves firmly grasping the leg with both hands just below the knee, with the thumbs on the tibial tuberosity.
While water skiing in Florida following final exams, a medical student falls and twists her ankle. Her foot is forcibly everted, which could cause a sprain of which ligament?
Deltoid The deltoid ligament connects medial malleolus with talus, navicular & calcaneus. It is on the medial side of the ankle joint, and its role is to prevent the ankle from dislocating when forcibly everted. So, if a foot was strongly everted, the deltoid ligament might tear.
The fibrocartilaginous structure which deepens the shoulder socket is the:
Glenoid labrum The glenoid cavity of the scapula provides a site where the head of the humerus articulates with the scapula.
-year-old child walking hand-in-hand with her father screams in pain as he jerks her quickly up onto the curb to dodge a speeding car. The examining physician calls it a case of "pulled elbow", a dislocation sometimes seen in young children and caused by:
The head of the radius slipping part way out of the annular ligament The defininition of the pulled elbow is that the head of the radius is pulled out of the annular ligament and is no longer attached to the ulna.
What is the drawer test and what does it test for?
designed to test integrity of anterior and posteiror curciate ligaments grasp leg with both hands just below knee, with thumbs on tibial tuberosity, w knee flexed, you push and pull on leg in line parallel to long axis of femur if it moves too far anteriorly--> ruptured anterior cruciate ligament, posterily--> ruptured posterior cruciate ligament
Why do children get pulled elbows?
dislocate joint bc radial heads are somewhat small in relation to size of anular ligament injury often occurs when childs upper limb is pulled while forearm is pronated, following injury, child cannot supinate her hand
What is a separated shoulder?
dislocation of AC joint injury most often occurs from hard fall on shoulder w impact taken by acromion or fall on outstretched limb severe if AC and coracoclavicular ligaments are torn
Deltoid keeps the foot from
everting
What is the epiphyseal plate/ growth plate?
example of synchondrosis, which is a temporarly cartilaginous joint present in growing bones eventually ossifys into solid bone and cartilage disappears
What is a pulled elbow?
head of radius pulled out of annular ligament and is no longer attached to ulna anular ligament should encircle head of raidus at proximal radio ulnar joint, forming a collar, holding head of radius against ulna without directly attaching to the radius, this allows radius to move freely at proximal articular w humerus
What is a shoulder separation?
injury to AC joint w third degree separation, you have total disruption of joint and ligament, and would see elevated of distal end of clavicle w respect to acromoion on injured side
In an auto accident, the patient's knee strikes the dashboard which in turn pushes the head of the femur posteriorly out of its socket. Which ligament is most likely ruptured by this posterior dislocation?
ischiofemoral Three ligaments comprise the hip joint capsule: pubofemoral, iliofemoral, and ichiofemoral. The iliofemoral ligament forms the anterior wall of the hip capsule, the pubofemoral lies beneath the joint, and the ischiofemoral ligament forms the posterior free margin of the hip capsule. Since the ischiofemoral ligament is the posterior edge of the hip capsule, it is the ligament that is most likely to be injured if the femur is dislocated posteriorly.
Why is the medial meniscus often injured in result of a knee sprain?
medial collateral ligament (tibial collateral ligament) is attached to the medial meniscus of the knee cliunically significant bc injury to MCL can reuslt in tear to medial meniscus can be cause dby blow to lateral knee
One of the menisci of the knee is often injured in a sprain of the knee because the:
medial collateral ligament is attached to the medial meniscus The medial collateral ligament (tibial collateral ligament) is attached to the medial meniscus of the knee. This is clinically significant because an injury or tear to the MCL can result in tearing to the medial meniscus.
Which joint would be subject to synovitis (inflammation of the synovial membrane)?
metacarpophalangeal This question is asking you to pick what joint, of the joints listed, is the synovial joint. And the only one which fits the bill is the metacarpophalangeal joint, which is a condyloid synovial joint, meaning that it can move in a sagittal and coronal plane.
A soldier developed "fallen arches" from marching with a heavy pack in boots that lacked arch support. The ligament that normally supports the head of the talus and is primarily responsible for holding up the medial longitudinal arch of the foot is the:
plantar calcaneonavicular (spring) The plantar calcaneonavicular ligament (spring ligament) connects the sustentaculum tali with the plantar surface of the navicular bone.
A two year old child will not go to take her nap. Her mother tightly holds her left hand as she leads her to the bedroom. Refusing to go further, the child suddenly attempts to jerk away and then sits down screaming and holding her left elbow. In a attempt to calm her down her mother offers her a cookie, but she cannot supinate her left hand to receive it. Which joint was dislocated?
proximal radio-ulnar joint This girl has suffered a pulled elbow--the head of her radius has been pulled out of the annular ligament and is no longer attached to the ulna.
What 3 ligaments form the hip joint capsule?
pubofemoral, iliofemoral, ischiofemoral iliofemoral= anterior wall pubofemoral= beneath the joint ischiofemoral= posterior free margin of the hip cpasule (most likely to be injured if femur is dislocated posteriorly)--> classic for car accidents
The interosseous membrane between radius and ulna is the uniting strucutre in a type of fibrous joint classifed as...
syndesmosis= fibrous membrane or ligament that joins 2 bones another example is tibia and fibia
what kind of joint is metacorphphalngeal?
synovial
