Five signs an ACL injury may need reconstruction

A torn anterior cruciate ligament does not automatically mean surgery. What decides it is whether the knee is unstable in daily life, and what you are asking the knee to do afterwards.

The five that matter

• The knee gives way when you turn, pivot or change direction. This is the single most important sign.
• It happened with a pop and swelling within hours. Rapid swelling after a twisting injury suggests bleeding inside the joint.
• You cannot trust it. Patients describe hesitating before stepping off a kerb long before they describe pain.
• Repeated episodes of instability. Each one risks further damage to the meniscus and cartilage, which is the real argument for reconstructing rather than waiting.
• You need to return to a pivoting sport, or to work involving ladders, uneven ground or carrying loads.

Why some tears are managed without surgery

• Some people are what is sometimes called a coper: the knee stays stable with strong muscles and no pivoting demands. For them, structured rehabilitation can be the right answer.
• Age alone does not decide it. Demand does.

What happens first, either way

• Swelling is settled and movement restored before any decision is made. Operating on a stiff, swollen knee tends to produce a stiff knee.
• Physiotherapy comes before surgery, not only after it. This is often the part people are most surprised by.

The associated injuries

• The ACL rarely tears alone. The meniscus and the cartilage surfaces are assessed at the same time, and what is found there frequently changes the plan.