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Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction — arthroscopic reconstruction of the torn ACL using a graft.

Surgical procedure in which the torn anterior cruciate ligament, which provides knee stability, is reconstructed arthroscopically using the patient's own tendon (hamstring or patellar) or a donor graft.

Indication

  • Complete ACL tear confirmed by MRI
  • Recurrent knee giving way and functional instability
  • Goal of returning to sport in active, young patients
  • Accompanying meniscal tear or cartilage damage
  • Persistent symptoms despite conservative treatment (rehabilitation, brace)
  • Need for knee reliability in athletes performing pivoting sports

Preparation

  • Detailed examination, MRI and weight-bearing knee X-rays to assess the tear and accompanying lesions
  • A 2-4 week pre-operative prehabilitation program (knee range-of-motion and strengthening exercises) is recommended
  • No food or drink for 6-8 hours before the procedure
  • Blood-thinning medications are stopped with physician approval
  • Stopping smoking 2-4 weeks beforehand is important for graft healing

How it's performed

  1. General or regional anesthesia is administered
  2. Graft selection: hamstring tendon (often the first choice — small incision, less anterior knee pain), patellar tendon (bone-tendon-bone, the older standard, may be preferred by athletes), or allograft (donor)
  3. Two to three small arthroscopic incisions are made around the knee; intra-articular structures are evaluated and any meniscal or cartilage procedures are performed
  4. Tunnels are drilled in the tibia and femur
  5. The prepared graft is passed through the tunnels and fixed with screws or endobutton systems
  6. After stability is confirmed, incisions are closed and a knee brace is applied

Post-procedure

  • Discharge after one night in hospital
  • Partial weight-bearing with crutches for the first 2 weeks; gradual full weight-bearing over 2-6 weeks
  • A knee brace is used for 2-4 weeks (per surgeon preference)
  • Staged physical therapy for 4-6 months (range of motion, muscle strength, proprioception)
  • Return to straight-line running at 3-4 months and to pivoting sports at 6-9 months; assessed with athlete tests (hop test, isokinetic testing)

Risks

  • Infection (possible with any surgical procedure)
  • Graft failure or re-rupture (5-10%)
  • Limited joint range of motion (arthrofibrosis)
  • Donor-site complaints (posterior thigh weakness with hamstring grafts; anterior knee pain with patellar grafts)
  • Vascular or nerve injury (rare)
  • Deep vein thrombosis (DVT)

FAQ

Is a hamstring graft or a patellar tendon graft better?

Both grafts have advantages. The hamstring graft offers a small incision and less anterior knee pain, while the patellar tendon graft (bone-tendon-bone) may be preferred in athletes for faster bone-to-bone healing. The choice depends on patient age, sport, anatomy and surgeon experience.

When can I return to sport after ACL surgery?

Return to pivoting sports (football, basketball, skiing) is generally targeted at 6-9 months. Straight-line running may begin at 3-4 months. The decision is made based on physical therapy progress, strength testing and surgeon approval.

Is surgery mandatory for an ACL tear?

Surgery is recommended for active athletes, young patients and those with functional instability. In low-activity patients with a sedentary lifestyle, conservative management with rehabilitation and bracing is possible. The decision is individualized.

How long does post-operative physical therapy last?

A staged program lasts 4-6 months. The first weeks focus on range of motion, then strength and balance work, and finally pivoting and plyometric exercises. Consistent physical therapy is the cornerstone of success.