The formation of sequestrum and involucrum is seen in the pathogenesis of:

DSSSB 12 August 2024

Medical Surgical Nursing

Easy

Appeared in: DSSSB 12 August 2024

Explanation

Osteomyelitis is an infection of the bone and bone marrow, most commonly caused by bacteria like Staphylococcus aureus.
The infection leads to inflammation and increased pressure within the bone, which compromises blood supply and causes a portion of the bone to die (necrosis). This dead piece of bone is known as a sequestrum.
In response, the body attempts to contain the infection by forming a layer of new, living bone (an involucrum) around the sequestrum.
The presence of both a sequestrum and an involucrum is the hallmark pathological finding in chronic osteomyelitis.

Option A: Gouty arthritis is a metabolic disorder characterized by the deposition of urate crystals in joints, leading to inflammatory arthritis. It does not involve bone infection or the formation of sequestra and involucra.
Option B: Osteoarthritis is a degenerative joint disease involving the breakdown of cartilage and the formation of bone spurs (osteophytes). It is a 'wear and tear' condition, not an infectious one.
Option D: Paget's Disease is a chronic condition of disordered and accelerated bone remodeling. It results in weakened, enlarged, and deformed bones but does not involve an infectious process leading to sequestrum formation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathogenesis of Osteomyelitis as background academic context rather than a clinical decision trigger.
The presence of a sequestrum is a major clinical challenge because it is avascular (lacks blood supply). Systemic antibiotics cannot penetrate it, making it a persistent source of infection.
Treatment for chronic osteomyelitis with a sequestrum often requires surgical intervention (sequestrectomy) to remove the dead bone, in addition to long-term antibiotic therapy.
What if? If a patient with a history of a bone fracture develops a non-healing wound over the site with persistent drainage, a nurse should have a high index of suspicion for chronic osteomyelitis with sequestrum formation, and the healthcare team should be alerted for further investigation (e.g., imaging).

How to Approach the Question

This is a factual recall question testing knowledge of pathophysiology.
First, identify the key terms in the question: 'sequestrum' and 'involucrum'.
Recall the definitions of these terms. 'Sequestrum' refers to a piece of dead bone that has become separated during necrosis. 'Involucrum' is a layer of new bone growth outside the existing bone.
Connect these specific pathological features to the correct disease process. These terms are uniquely characteristic of chronic osteomyelitis.
Evaluate the options to eliminate those with different pathophysiological mechanisms (crystal deposition, degeneration, or disordered remodeling).

Concept Tested & Keywords

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E6 Pathology-Vandana Puri & Kavita Gaur Textbook of Pathology and Genetics pp. 268-270, 269-271

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 1185-1187