ACL and PCL tears: what patients should know

The anterior cruciate ligament and posterior cruciate ligament control different directions of shin-bone movement. Either may be partly or completely torn, and both can be injured in a forceful knee event.

An ACL injury often follows a sudden pivot, awkward landing or rapid change of direction. A PCL injury more often follows force that drives the shin backwards while the knee is bent. Pain, swelling, reduced movement or a sense that the knee gives way can occur, but symptoms alone cannot show which ligament is damaged.

A clinician checks stability in several directions and looks for associated meniscus, cartilage or other ligament injury. An X-ray may exclude a fracture, while MRI can clarify soft-tissue damage when the result will guide care.

Stop sport and avoid twisting, deep squats and any movement that makes the knee buckle. Use a cold pack wrapped in cloth, elevate the leg and reduce weight-bearing if walking is painful or unstable. A brace or crutches should be fitted or advised by a clinician so they support the knee without creating pressure problems.

Treatment depends on instability, combined injuries, daily demands and sporting goals. Rehabilitation builds movement, muscle control and confidence; selected injuries may need surgical reconstruction. Return to running or pivoting sport should follow functional testing rather than pain relief alone.

Seek urgent assessment after major trauma if the knee looks deformed, you cannot bear weight, the foot becomes cold or numb, or pain and swelling are rapidly worsening. A locked knee that cannot fully bend or straighten also warrants prompt review.

Arrange a musculoskeletal appointment when instability persists, swelling returns with activity or normal walking remains difficult. Repeated giving way can expose other knee structures to further injury even when discomfort is modest.

Ask which ligament appears injured, whether the tear seems partial or complete, and whether another structure may also be involved. Discuss what movements are safe now, whether you need a brace or crutches, what rehabilitation milestones apply and how your work or sport affects the treatment choice.