OCC Anatomy & Physiology Relevant to Casting 5

Question 1

Which anatomical feature of the tibia makes it the weight-bearing bone of the leg, as opposed to the fibula?

Accepted Answer

The tibia articulates with the femur at the knee and talus at the ankle

Answer

The tibia is the primary weight-bearing bone because it forms the tibiotalar (ankle) joint inferiorly and the tibiofemoral joint superiorly, directly transmitting axial load.

Question 2

Which ligament of the lateral ankle complex is most frequently torn in an inversion sprain and is commonly protected by short-leg casting?

Accepted Answer

Anterior talofibular ligament (ATFL)

Answer

The ATFL is the weakest of the three lateral ankle ligaments and the first to tear during an inversion-plantarflexion injury.

Question 3

Synovial fluid is produced by which cellular layer within a joint and serves to lubricate and nourish articular cartilage?

Accepted Answer

Synoviocytes of the synovial membrane

Answer

Synoviocytes lining the synovial membrane secrete hyaluronate-rich fluid that lubricates articular surfaces and delivers nutrients to avascular cartilage.

Question 4

The radial nerve is most vulnerable to injury at which anatomical location during humeral shaft fractures or improper cast padding?

Accepted Answer

Spiral groove of the humerus

Answer

The radial nerve passes through the spiral (radial) groove of the posterior humerus, making it susceptible to injury in mid-shaft humeral fractures.

Question 5

Which physiological process, driven by the inflammatory response, is responsible for clearing debris and necrotic tissue in the first stage of fracture healing?

Accepted Answer

Phagocytosis by macrophages and neutrophils

Answer

In the inflammatory phase, macrophages and neutrophils infiltrate the fracture hematoma to phagocytose debris and necrotic tissue, initiating the healing cascade.

(OCC) Orthopedic Casting Certification Practice Test

(OCC) Orthopedic Casting Certification Practice Test

OCC Anatomy & Physiology Relevant to Casting 5