An older male reports to the clinic nurse that he sometimes feels chest pressure and becomes breathless. He further describes an event where he had to sit for about one hour before he felt better. He is asymptomatic at rest, but is concerned that he has had a heart attack. This clinical picture is consistent with which cardiac ischemic event?

Chronic osteoarthritis (OA) is a degenerative joint disease characterized by the breakdown of joint cartilage and underlying bone changes. The pathophysiological process of OA involves various factors contributing to joint pain and inflammation. Here's why option C is the correct choice:

A) Inflammation results from deposition of crystals in the synovial space of joints producing irritation:

This statement is more characteristic of crystal-induced arthritis, such as gout or pseudogout, where crystals (e.g., urate or calcium pyrophosphate crystals) deposit in the joints and cause acute inflammation and irritation. While inflammation may occur in OA, it is primarily a result of mechanical stress and cartilage degradation rather than crystal deposition.

B) Inflammation is caused by immune complex and autoantibody deposition in connective tissue:

This statement is more characteristic of autoimmune diseases such as rheumatoid arthritis (RA), where immune complex deposition and autoantibody production lead to chronic inflammation and joint damage. In OA, inflammation is not primarily mediated by immune complex deposition or autoantibodies.

C) Joint inflammation occurs when chondrocyte injury destroys joint cartilage, producing osteophytes:

Correct. In osteoarthritis, joint inflammation occurs as a result of chondrocyte injury and cartilage breakdown. Over time, the degenerative changes in the joint lead to the formation of osteophytes (bone spurs) at the joint margins. These changes can irritate surrounding tissues, including the synovium, ligaments, and tendons, contributing to joint pain and inflammation.

D) Joint destruction happens due to an autoimmune inflammation involving IgG response to an antigen:

This statement is more characteristic of autoimmune arthritis, such as rheumatoid arthritis (RA), where autoantibodies (e.g., rheumatoid factor, anti-citrullinated protein antibodies) target joint tissues, leading to chronic inflammation and joint destruction. In OA, joint destruction primarily results from mechanical stress and wear-and-tear on the joint structures rather than autoimmune mechanisms.

A) Peripheral neuropathy:

Peripheral neuropathy involves damage to the peripheral nerves and is not directly related to the described crushing injury. While nerve injury can occur as a result of trauma, the signs and symptoms described in the scenario, such as unequal strength between the left and right thighs, are more indicative of a potential vascular or musculoskeletal issue rather than peripheral neuropathy.

B) Osteomyelitis:

Osteomyelitis is a bone infection that can occur secondary to trauma or as a complication of open fractures. While it is possible for a crushing injury to lead to osteomyelitis if there is bone involvement or an open wound, the scenario mentions that x-rays revealed no broken bones. Additionally, the signs and symptoms described, such as bruising and swelling of the thighs, are not specific to osteomyelitis.

C) Fat embolism:

Fat embolism occurs when fat globules enter the bloodstream, often following traumatic injury to long bones or orthopedic procedures. While a crushing injury can theoretically lead to fat embolism, the absence of long bone fractures in the x-rays makes this less likely. Additionally, fat embolism typically presents with respiratory symptoms such as dyspnea and hypoxemia, which are not described in the scenario.

D) Compartment syndrome:

Correct. Compartment syndrome is a serious condition that can occur following a crushing injury, especially in the extremities. It is characterized by increased pressure within a muscle compartment, leading to compromised blood flow and potential tissue damage. Signs and symptoms of compartment syndrome include severe pain, swelling, bruising, decreased or absent pulses, and neurological deficits. The unequal strength between the left and right thighs could indicate neurological deficits due to compromised blood flow or nerve compression, making assessment for signs of compartment syndrome crucial in this client's plan of care. If compartment syndrome is suspected, prompt medical intervention, such as fasciotomy to relieve pressure, may be necessary to prevent complications.