Condition · Knee
Anterior cruciate ligament (ACL) tear
The anterior cruciate ligament controls translation and rotation of the knee. There is no single treatment algorithm for an ACL tear: activity level, giving-way episodes, associated meniscal injuries and the patient's goals are decisive.
Clinical context
What you should know
Some people function well without surgery during straight-line activities; others remain unstable despite appropriate rehabilitation. Chronological age alone does not determine whether surgery is indicated.
Meniscal, cartilage and other ligament injuries must be assessed together because they may change the timing, technique and rehabilitation plan.
First step
Consultation and assessment
The clinical examination tests stability and compares both knees. Radiographs exclude fractures or other problems, while MRI defines the ACL tear and associated injuries when the result is relevant to the decision.
Before surgery, the knee usually needs to regain full extension, swelling must be controlled and some strength restored. Surgery is discussed after assessing the risk of further giving-way episodes.
Stepwise treatment
Options are chosen according to the diagnosis and treatment goal
Conservative treatment
- structured rehabilitation for movement, strength, balance and neuromuscular control
- temporary or permanent modification of pivoting activities
- a functional brace in selected situations, without replacing muscular control
- reassessment if instability persists or locking and meniscal symptoms develop
Medication, injections and devices each have their own indications and contraindications. They are not recommended automatically and do not replace a diagnosis or monitoring of the response.
When surgery is considered
ACL reconstruction uses a graft and is considered for symptomatic instability, pivoting activities or associated injuries that benefit from a stable knee. Injections cannot restore the torn ligament.
Do not delay
Signs that require prompt assessment
- deformity, inability to bear weight or suspected dislocation after injury
- a cold or pale foot, or new numbness
- a locked knee or marked swelling after injury
In an emergency or if symptoms are severe, call 112 or go to the nearest emergency department.
Frequently asked questions
Concise answers, without blanket promises
Does an ACL tear automatically require surgery?
No. The decision takes into account perceived instability, type of activity, associated injuries and the response to rehabilitation.
When can I return to sport?
Return to sport is based on healing, strength, control, functional testing and confidence, not simply on a fixed number of months.
Editorial responsibility
Medically reviewed content
Dr. Răzvan Anițaș
Consultant orthopaedic and trauma surgeon; PhD in medical sciences
Last editorial update: 22 August 2026
First step
Consultation, diagnosis and a clearly explained plan
This content is educational and does not replace medical assessment. Similar symptoms can have different causes and require different treatments.