3 Mount Elizabeth, #08-05 Mount Elizabeth Medical Centre, Singapore 228510 | Tel: +65 6733 4565 | Mobile: +65 9766 4565 | Email: clinic@orionortho.sg
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What happens after ACL reconstruction surgery?


The Anterior Cruciate Ligament (ACL) sits in the middle of the knee and provides stability when we twist and pivot during daily activities and sports. While the ACL is a robust ligament, it can still rupture if too much force is applied to it. Without an ACL, you may still walk and jog, but the knee will feel unstable during pivoting movements with stairs or sports such as basketball or football. The ACL is reconstructed using your hamstrings to restore the stability of your knee. 






Post ACL Reconstruction Rehabilitation

Physiotherapy and rehabilitation are crucial after surgery so that you may have a good functional outcome and return to sports sooner rather than later. Most post ACL reconstruction rehab protocols are broken up into several phases (Immediate, Intermediate, Late) and each phase has its own aims and targets. Not all patients will have the same rehabilitation as there might have been differences in the surgery they had. In addition to the ACL recon, they might also have had repairs of meniscus tears or treatment of cartilage injuries as well. 


Phase 1 (Immediate post op, 0-2 weeks after surgery)

Rehab aims: 

  • Protect the new ACL graft
  • Reduce swelling, inflammation
  • Restore full knee extension, gradually improve flexion

Patient Education:

  • Keep your knee straight in the brace
  • Ice your knee to reduce swelling
  • Use crutches to help you get around
  • Partial weight bearing for 4-6 weeks


Phase 2: Intermediate (3-5 weeks after surgery)

Rehab aims: 

  • Continue to protect the graft
  • Maintain full knee extension, restore full knee flexion
  • Improve your walking pattern (gait)

Patient Education: 

  • Stationary bicycle
  • Gentle stretching and strengthening of leg muscles: quads, calves, hamstrings
  • Improve balance with single leg stance, partial squats


Phase 3: Late (6-8 weeks post op)

Rehab aims: 

  • Continue to protect ACL graft
  • Maintain full range of motion
  • Safe progression of strengthening exercises

Patient Education: 

  • Cardio and gym exercises: leg press machine, swimming, pool jogging, lunges
  • Improve single leg balance


Phase 4: Transitional 9-12 weeks post op

Rehab aims: 

  • maintain full knee range of motion
  • Promote better balance and leg strength

Patient Education: 

  • May begin sport specific training but at lesser pace and intensity
  • Continue to strengthen muscles and improve knee range of motion


Phase 5: Early return to sports (3-5 months post op)

Rehab aims:

  • Safe and progressive strengthening
  • Safely initiate sport specific training program 

Patient education: 

  • Interval running program
  • Strength and agility program


Phase 6: Unrestricted return to sport (>6 months post op)

Rehab aims:

  • Continue strengthening and balance exercises
  • Improved performance with sport specific drills
  • Safe progress to sports
  • (torsional activities may be delayed due to risk of graft re-rupture)

Patient education: 

  • Progressive strengthening exercises
  • Manage sports performance under supervision
  • Non contact practice - Full practice - Full play (9-10 months)
  • Avoid early pivoting sports within 9 months

What can I do to Make My Knee Heal Faster? 

Your surgeon and physiotherapist would give you specific targets to meet after your surgery. While we want to make a quick recovery, there is also a need to protect the new ACL graft and prevent a re-rupture. 

  • Comply with the advice given by your surgeon and physiotherapist to manage the knee swelling, movements and strengthening during your rehabilitation. 
  • To manage knee swelling, apply ice over your knee and elevate your leg over a pillow. Compression around the knee will also reduce swelling. 
  • Do attend the planned consults with your surgeon and physiotherapist to ensure you are recovering well and do not encounter any complications.
  • Keep up with recommended exercises. Consistent stretching and strengthening are important.  


What are some things I should avoid?

In the early stages of your recovery, you will have to wear a knee brace and use crutches when you walk. This protects the ACL graft and avoids excessive swelling. 

Avoid pivoting sport in the first 9 or 10 months after surgery. The ACL graft is still vulnerable to rupture if excessive forces are applied to the knee too soon. 

Please seek the advice of your surgeon and physiotherapist before returning to competitive sports. A formal assessment will be done for you to ensure you may transition to sports safely. 

ACL Surgery Complications 

While ACL reconstruction is one of the commonest and most successful orthopaedic surgeries, it has a 75 to 97 percent success rate. Like all surgical procedures, there are possible complications which patients may face. Some complications are minor while others are major. 

Minor complications:

  • Superficial wound infection
  • Skin numbness
  • Minor knee stiffness

Major complications: 

  • Deep knee joint infections
  • Severe knee stiffness
  • Knee instability 
  • ACL graft re-rupture

Your surgeon will follow you up after surgery and ensure these complications do not occur. You may be on antibiotics and have your wounds cleaned regularly to prevent infections. Progressive physiotherapy and rehab are crucial to manage the movement of your knee while protected the integrity of your new ACL graft. 

Some patients experience a re-rupture of their ACL. If this happens within just a few months of surgery, it may either be a technical error of surgery or the patient returned to pivoting sports too soon. Some patients rupture their new ACL several years after their surgery due to the high intensity of their sport of choice. If this happens, a revision ACL reconstruction may bee performed. 

What is Revision ACL Reconstruction Surgery?

Revision surgery describes a repeat surgical procedure undertaken to improve the condition of the patient. Specific to ACL related surgery, this is roughly 3 to 5 percent of all ACL reconstruction operations performed. While primary ACL reconstruction is very successful, revision surgeries often have inferior outcomes. 

The new ACL graft will either be harvested from the same knee in the form of a quadricep or patella tendon graft or from a cadaveric source of allograft (from a person who has passed away). Cadaveric grafts are generally not as strong and robust as patients’ own tendons and may rupture again in future. 

Do I Need an ACL Revision Surgery?

The ACL is important to stabilise the knee during twisting and pivoting movements. If your knee remains unstable after your surgery, your surgeon will perform a clinical examination of your knee to assess its integrity and stability. A repeat MRI scan may be done to exclude a rupture of the ACL graft. If the ACL graft is re-torn and you would like to return to pivoting sports like football or basketball, then revision ACL reconstruction surgery may be required. 

Frequently Asked Questions 

How long does it take to walk and drive after ACL surgery? 

You should be able to walk without crutches after about 4 weeks. You should be able to drive once you are walking without crutches. Please consult your doctor before you come off your knee brace and crutches. 

How should I sleep after ACL surgery? 

Sleep with your legs propped up by a pillow under your heel. 

Is it common to retear your ACL? 

No, it is not common to retear your ACL. The risk of re-rupturing your reconstructed ACL is between 1 to 20 percent. This depends on your rehab journey and the type of sport you play. 

When can I return to sports?

The timeline varies for a lot of people. On average, you can return to sports 8 to 12 months post surgery. Your physiotherapist will assess you for the specific sport that you play before giving you the go-ahead to return to unrestricted sporting activities.


Our Location

  • 3 Mount Elizabeth, #08-05 Mount Elizabeth Medical Centre, Singapore 228510
  • +65 6733 4565
  • +65 9766 4565
  • Mon-Fri 8:30am - 5:30pm
    Sat 8:30am - 12:30pm
    Sun/Ph Closed

Contact Form

Our Location

  • 3 Mount Elizabeth, #08-05 Mount Elizabeth Medical Centre, Singapore 228510
  • +65 6733 4565
  • +65 9766 4565
  • Mon-Fri 8:30am - 5:30pm
    Sat 8:30am - 12:30pm
    Sun/Ph Closed

Contact Form