Joints Flashcards
What are primary cartilage joints?
These are typically temporary articulations of bone made up of hyaline cartilage (Type II collagen). These are present during development of the long bones at the epiphyseal plate.
What are secondary cartilaginous joints?
These are made up of fibrocartilage. An example of this joint type is the intervertebral disks that join the vertebrae together and allow for limited movement of the spine.
What are fibrous joints?
Articulating bones are connected by ligaments or fibrous membranes. Movement in these joints may be limited or nonexistent, depending on the fibrous limitations connecting the bones. Examples include the sutures of the skull, pubic symphysis, and the radial/ulnar joint.
This joint allows us to nod “yes”
Atlanto-occipital joint
Synovial joint between the atlas (c1) and the occipital condyles
This joint allows us to nod “no”
Atlantoaxial joint
What exactly is the purpose of the acromioclavicular joint?
A plane type of synovial joint between the lateral end of the clavicle and acromion of the scapula. Strong ligaments hold this thing together, but a fall onto the shoulder or outstretched arm may separate it.
Anterior dislocation of the glenohumeral joint can cause damage to what?
Damage to the axillary nerve
Posterior dislocation of the glenohumeral joint
Electrocution injuries…huh?
What three parts make up the elbow?
- Ulnohumeral: Reinforced by MCL
- Radiohumeral: Reinforced by LCL
- Radioulnar: Reinforced by annular ligament
Nursemaid’s elbow and how we fix it
A pulled elbow when the arm is pronated, tearing the annular ligament. This causes the elbow to sublux, causing pain secondary to pinching of the annular ligament in the elbow joint.
Reduced by supinating the forearm of a flexed elbow.
Why are lateral meniscus injuries less common than medial meniscus injuries?
The MCL is attached to the medial meniscus, but the lateral is not attached to the LCL. With fewer attachments, even with a blow medially, the lateral meniscus is difficult to tear.
What is the “unhappy triad” seen typically with soccer injuries?
Athlete is hit on the lateral side and twists the flexed knee, causing a tear of
- Tibial ligament (MCL)
- Then medial meniscus
- Then anterior cruciate ligament
This leads to valgus (abducted) deviation and a positive anterior drawer sign
Mechanics on an inversion ankle sprain
Tearing of the lateral ligament (anterotalofibular ligament or ATFL)
Recall that eversion sprains result in Pott’s.
Bennet vs. Boxer’s fracture
Bennet - Fracture at the base of the metacarpal of the thumb
Boxers - 2nd and 3rd metacarpals in skilled boxers and the 5th in unskilled.
