arm pathology

Practice flashcards covering the five stages of bone healing, specific types of humeral fractures, and clinical classifications.

Haematoma formation

The first stage of fracture healing occurring $6-8$ hours after injury, where a blood clot forms in the medullary cavity and serves as a fibrin network for angiogenesis and cellular invasion.

Cellular proliferation

The second stage of fracture healing characterized by an inflammatory response and cellular invasion by neutrophils and macrophages to remove debris.

Callus formation

The third stage of bone healing, lasting about $3$ weeks, where mesenchymal stem cells differentiate into chondrocytes and fibroblasts to produce a fibrocartilaginous procallus.

Ossification

The fourth stage of healing, lasting up to $6$ weeks, where osteoblasts deposit new bone tissue and replace cartilage with woven or primary bone.

Remodelling

The final stage of bone healing where osteoclasts dissolve excess bone and osteoblasts lay down lamellar bone; this process can take months to years.

Supracondylar fracture

A fracture common in children around $6-7$ years old, typically extra-articular and involving the thin bone between the coronoid fossa and the olecranon fossa.

Gartland classification Type I

A supracondylar fracture that is undisplaced.

Gartland classification Type II

A supracondylar fracture that is displaced with an intact posterior cortex, which may or may not involve rotational deformity.

Gartland classification Type III

A supracondylar fracture involving complete displacement.

Volkmann’s contracture

A potential complication associated with supracondylar fractures.

Cubitus varus

A malunion or misalignment complication resulting from a supracondylar fracture.

Humeral shaft fracture (Bending force)

A type of injury that specifically produces a transverse fracture of the humeral shaft.

Humeral shaft fracture (Torsion force)

An injury caused by twisting that results in a spiral fracture of the humeral shaft.

Butterfly fragment

A specific bone fragment shape resulting from a combination of bending and torsion forces in a humeral shaft fracture.

Anatomical Neck fracture

A proximal humeral fracture through the anatomical neck; it has a much higher incidence of AVN (avascular necrosis) than surgical neck fractures.

Surgical Neck fracture

The most common fracture of the proximal humerus, which is extracapsular and has a relatively low incidence of AVN.

Hill-Sachs lesion

A fracture in the posterolateral head of the humerus caused by impaction against the glenoid rim.

Greater tuberosity fractures

Fractures commonly associated with anterior shoulder dislocation; if displaced, they are often linked to longitudinal rotator cuff tears.

Angiogenesis

The formation of new blood vessels, facilitated by the fibrin network of the fracture haematoma.

Atrophic nonunion

A likely result for humeral fractures left with good alignment but a significant gap between fracture fragments.