Final answer:
The correct term for the deterioration of the back of the kneecap causing crepitus is chondromalacia patellae, a condition that can lead to knee pain and instability due to cartilage breakdown.
Step-by-step explanation:
The correct term for the deterioration of the back of the kneecap causing crepitus is chondromalacia patellae. This condition involves the softening and breakdown of the cartilage on the underside of the kneecap, which can lead to roughening and irritation when the kneecap rubs against the thigh bone during movement. The presence of crepitus, or a crackling sound, during knee flexion and extension is a common symptom of this disorder.
Knee injuries are frequently encountered, as the joint relies significantly on muscles and ligaments for stability. Injuries to the knee can lead to pain and instability, with damage to soft tissues such as the anterior and posterior cruciate ligaments often leading to such symptoms. Such injuries can occur through direct trauma or dynamic movements that overstress the joint.