Which condition is primarily associated with inflammation and pain in tendons?

Tendonitis is primarily characterized by inflammation and pain in the tendons, making it the correct answer. This condition arises when a tendon, which connects muscle to bone, becomes irritated or inflamed, often due to repetitive motion, overuse, or injury. The hallmark symptoms of tendonitis include localized pain, swelling, and tenderness around the affected tendon, often exacerbated by movement.

In contrast, other conditions like an Achilles tendon rupture, muscle strain, or joint dislocation involve different mechanisms of injury. An Achilles tendon rupture typically presents with sudden, acute pain and an inability to flex the foot, signaling a complete tear of the tendon rather than inflammation. A muscle strain involves injury to muscle fibers rather than tendons, leading to its own set of symptoms such as bruising and weakness. Joint dislocation refers to the complete displacement of a bone from its joint, causing significant pain and dysfunction in the joint area but not specifically focusing on tendon inflammation. Thus, tendonitis remains the clear choice in relation to tendon-specific inflammation and pain.