Upper Extremity I Flashcards
Which bones would you find in the proximal and distal rows of carpal bones in the hand?
proximal: scaphoid, lunate, triquietrum, pisiform
distal: trapezium, trapezoid, capitate, hamate
What are gullies’ lines?
out line the arches created by the rows of carpal bones (represent proper alignment)
What factors lead to poor healing in a scaphoid fracture?
- scaphoid is almost completely covered in intra-articular cartilage (there is little or no callus formation and no periosteum to contribute healing cells)
- majority of blood flows distal to proximal in the scaphoid, and proximal fractures often do not get adequate blood flow
- non-displaced fractures often no evident on initial radiographs (must look for snuff box tenderness)
- scaphoid is responsible for much of the stability between distal and proximal rows of carpal bones
What factors lead to poor healing in a scaphoid fracture?
- scaphoid is almost completely covered in intra-articular cartilage (there is little or no callus formation and no periosteum to contribute healing cells)
- majority of blood flows distal to proximal in the scaphoid, and proximal fractures often do not get adequate blood flow
- non-displaced fractures often no evident on initial radiographs (must look for snuff box tenderness)
- scaphoid is responsible for much of the stability between distal and proximal rows of carpal bones
What techniques are used in improving scaphoid healing?
improve blood supply with a vascularized bone graft
restore technical stability by rigid internal screw fixation
What elements of history or other bony injury are associated with a distal radial fracture?
associated with FOOSH, often with a ulnar styloid fracture
can include a characteristic dinner fork deformity
How is a distal radius fracture treated?
blood supply usually good: periosteum, metaphysics and muscle/soft tissue
cast immobilization or fixation with early diagnosis
Describe a Boxer’s fracture.
angulated fractures of the 5th metacarpal, common from striking another object with fist
can be addressed with immobilization or internal fixation (good blood flow, not articular)
Describe a Bennett’s fracture.
intra-articular fracture of the first metacarpal caused by axial force directed against a flexed metacarpal
usually unstable, free articular fragment is held in place but the metacarpal is adducted by the abductor pollicis longus
Define avulsion and mallet fractures.
avulsion fracture: is an injury to the bone and/or tendon that occurs at the location of attachment
mallet fractures include the insertion of the terminal extensor and are a subtype of avulsion fracture
Define avulsion and mallet fractures.
avulsion fracture: is an injury to the bone and/or tendon that occurs at the location of attachment (depends on rate and magnitude of force re: bone v. tendon injury)
mallet fractures include the insertion of the terminal extensor and are a subtype of avulsion fracture
Describe the injury known as a bony skier’s thumb.
the ulnar collateral ligament of the thumb pulls its distal bony insertion away from the rest of the proximal phalanx
often due to hyperextension of the first metacarpal
Describe the mechanism of a scaphoid fracture.
scaphoid is bent across the rim of the radius during a fall on an outstretched hand (same as distal radius fracture mechanism)
Describe the mechanism of a triquetral fracture.
the dorsal portion of the triquetrum is pinched between the ulnar styloid and hammate, also via FOOSH
What is the mechanism/pathology of injury in tennis elbow?
degenerative damage to the lateral epicondyle, specifically the bony attachment primarily of the extensor carpi radialis braves, an epicondylitis (lateral epicondylosis)
