Fractures UE Flashcards
mechanisms of injury
- unloaded
- tension
- compression
- bending
- shear
- torsion
- combined loading
primary healing of fracture
- end-to-end fracture contact
- no callus formation
- healing in the intramedullary canal (ENDOSTEAL)
- visible on xray after months
- secondary to rigid fixation
- compression plating
secondary healing of fracture
- no fracture compression
- callus formation
- healing is OUTSIDE intramedullary canal (PERIOSTEAL)
- callus/bridging callus can be seen in xray after 2 weeks
- micromotion present
- casting, intramedullary nailing, neutralization plating
inflammation stage of fracture healing
- day 1-14
- blood vessels torn -> hematoma formation
- activated platelets release products and cause influx of inflammatory cells
- subperiosteal and endosteal cell proliferation
products released by activated platelets and cells of repait
- fibronectin
- pdgf
- tgf-b
- fibroblasts, endothelial cells, osteoblasts
- macrophages and neutrophils
- osteoprogenitor cells
repair stage of fracture healing
- 2nd to 6th week
- initiation of healing through restoration of blood supply to unite fracture fragments
what is soft callus formation
- osteoblasts form a bridge of woven bone over fracture site which provides support
- formation of connective tissue and angiogenesis = FIRST RADIOGRAPHIC SIGN of reuniting bones
remodeling stage of fracture healing
- consolidation
- woven bone is replaced by compact lamellar bone
- osteoclastic resorption + osteoblastic deposition
principles of fracture treatment
- restore articulating surface (only 2 mm displacement allowed)
- rigid fixation
- allow early range of motion
shoulder trauma is composed of __
clavicle, scapula, proximal humerus
t/f muscle attachments allow motion and don’t cause deformity when fractured
false, when fractured, muscles act as deforming force resulting in displacement
parts of the shoulder joint
- scapula: rotator cuff origin, fractured in high energy trauma
- proximal humerus: rotator cuff insertion
common sites of fractures on shoulder
- body of scapula
- spine of scapula
- glenoid
- coracoid process
first bone to ossify at 5th fetal week, and last to fuse at 25 years
clavicle
displacement due to clavicle in fractures
medial end is pulled inferiorly, lateral end is puller superiorly
t/f the longer the lever arm, the easier it is to perform range of motion
true, shortening = dec function because of dec in length of lever arm (more effort needed for elevation)
critical length for lever arm
2-2.5 cm
clavicular third fractures
- middle!!: allowable displacement of 2 cm shortening
- lateral: depending on location of fracture to coracoclavicular ligament
- medial: least common, only posterior displacement needs emergency surgery
absolute indications for fracture fixation
- open fractures
- skin tearing
- vascular injuries
relative indications for fracture fixation
- shortening more than 2 cm
- delayed union leading to nun-union within 3 mos
types of lateral third fractures
- type 1 and 3 are non-surgical
- type 2 is surgical
- fracture that displaces medial fragment superiorly = coracoclavicular ligament is torn
- coracoclavicular ligament= main stabilizer against vertical displacement
treament for clavicle fracture
- restores length/position to permit healing and maintain lever arm position
- internal fixation using intramedullary nail
- plates and screws
deformations from proximal humerus
- subscapularis = internal rotation
- infraspinatus and teres major = external rotation
- supraspinatus = abduction of shoulder
majority of rotator cuff muscle insertions are in __
greater tuberosity of proximal humerus
key issues in treatment of proximal humeral fractures
- viability of fragments (4 part fx = vascular necrosis)
- quality of bone
- degree of displacement (1 cm allowable)
- surgical skill, medical center support, post-op compliance
types of proximal humerus treatments
- open reduction internal fixation
- joint replacement
t/f humeral shaft fractures can almost always be treated non-surgically
true !! read
bony anatomy of elbow
- humerus
- ulna = flexion-extension
- radius: pronation-supination
- arc of motion is uniplanar (hinge joint)
common fracturs in the distal humerus
- supracondylar
- unicondylar lateral condyle
- intercondylar
t/f only supracondylar fractures are common in children
false, both supracondylar and lateral condylar are common in children
what are supracondylar fractures
- due to: thin cortices of distal humerus OR ligamental laxity
- tx: closed reduction and pinning
- cubitus varus deformity
what are lateral condylar fractures
- physeal fracture (growth plate injury)
- prone to displacement due to attachment of common extensors
- tx: open reduction, internal fixation, with pins
- deformity: cubitus valgus with tardy ulnar nerve palsy
clinical value of radial head
- pronation and supination
- 2nd stabilizer of elbow
what are radial head fractures
- fall on outstretched upper extremity with valgus force to elbow
- tx: save or replace radial head
what are coronoid fractures
- lose the power of elbow flexion
- stabilizes against posterior dislocation
- occur due to posterior elbow dislocations
regan morrey classification of coronoid fractures
- type 1: avulsion/shearing
- type 2: <50%
- type 3: >50% (needs fixation)
what are olecranon fractuers
- stabilizes against anterior dislocation
- fractured by avulsion or direct fractures
- tx: tension band wiring or plating
t/f adult forearm fractures are almost always indicated for surgery
true, conservative treatment allowed for children
deforming forces in the forearm
- supinator
- pronator teres
- pronator quadratus
what is monteggia fracture
- fracture of ulna with radial head dislocation
- tx: open reduction and plating
what is galeazzi fracture
- fracture of radius with ulnar head dislocation
- tx: open reduction and plating
