Recovery from an ACL reconstruction happens in stages over about a year. In each stage you work towards a few clear goals, and you move on to the next stage when your knee is ready, not on a fixed date.[1] Dr Vishal Pai recommends rehabilitation based on the Melbourne ACL Rehabilitation Guide 2.0, a widely used physiotherapy programme built around these milestones. The weeks below are a rough guide to what to expect and what to aim for at each stage.
At a glance
- Progress depends on your knee reaching each stage’s goals, not on the calendar.
- Getting your knee fully straight in the first few weeks is the most important early goal.
- Gentle jogging usually starts at around 3 to 4 months, if your strength allows.
- Dr Vishal Pai recommends at least 12 months, and passing return-to-sport testing, before you go back to competitive sport.
What happens in the first 2 weeks?
The first fortnight is about letting the knee settle after surgery. Dr Vishal Pai usually lets you put weight on your leg straight away, using crutches for balance and comfort. Most people stop using crutches within 2 to 3 weeks, once they can walk without a limp.
There are three goals in these early weeks:
- Get the knee straight. Gentle exercises help your knee straighten fully (extension).
- Settle the swelling. Ice, compression and keeping the leg raised all help. Dr Vishal Pai recommends ice for at least 20 minutes, 4 times a day.
- Get your thigh muscle working again. The quadriceps, the large muscle at the front of the thigh, often switches off after knee surgery. Simple tightening exercises help it start working again.
At this stage, it is best not to push hard on strength or bending. Your dressings come off and your stitches come out at the 2-week review.
Why does getting your knee straight matter so much?
A knee that won’t straighten fully makes you walk with a limp, overloads the front of the knee and can be hard to fix later. Bending usually comes back more easily with time, but straightening needs early attention. A knee that isn’t straight by about 4 weeks is more likely to stay stiff.[2] Some loss of straightening is also one of the most common problems after this operation. In a review of clinical trials, about 1 in 3 people still had a small loss of straightening at 12 months, and about 1 in 4 at 2 years.[3]
A few simple habits help. Don’t rest with a pillow under your knee, even though it may feel more comfortable. Do the straightening exercises your physiotherapist gives you several times a day. At your 8-week review, Dr Vishal Pai expects your knee to straighten fully and bend past 90 degrees.
What happens from 2 to 12 weeks?
This stage focuses on strength, balance and control. You usually start with bodyweight exercises such as bridges, calf raises, step-ups, small squats and standing on one leg. These then progress to a gym programme. A stationary bike is a good low-impact way to keep fit.
Let pain and swelling guide you. If your knee is more swollen or sore the next day, it is telling you that you have done too much, so ease back for a day or two.
As a rough guide, Dr Vishal Pai’s usual timings are:
- Swimming: from about 3 weeks, once the wounds have healed.
- Work: most people with a desk job return at about 3 to 4 weeks. Physically demanding work may need up to 6 weeks off.
- Driving: from about 4 weeks after surgery on your left knee if you drive an automatic. If the right knee was operated on, or you drive a manual car, it is about 6 weeks. Studies of braking reaction time after this surgery support waiting, particularly after surgery on the right knee.[4]
You are usually ready to move on to the next stage when there is little or no swelling, your knee moves fully and you can do a single-leg squat with good control.
When can you start running and jumping?
Dr Vishal Pai usually allows gentle, straight-line jogging from around 3 to 4 months, if your strength training is going well and your knee isn’t swelling. This is similar to common practice: across many rehabilitation studies, running was most often allowed at about 12 weeks.[5]
From around 4 to 6 months, hopping, landing, agility drills and changes of direction are added step by step. Technique matters as much as effort in this stage, particularly how you land from a jump. Your physiotherapist will compare the strength and hopping ability of your two legs to guide when to progress. At your 4-month review, Dr Vishal Pai checks the stability of the graft and the movement in your knee.
When can you go back to sport?
Dr Vishal Pai recommends waiting at least 12 months before you return to competitive sport, especially sports that involve pivoting, cutting or jumping. Time alone isn’t enough, though. Before you return, you need to be ready both physically and mentally, and everyone’s recovery is different.
Physical readiness is checked with return-to-sport testing, which includes strength tests, hop tests and movement assessments. In one study of athletes who played pivoting sports, more even quadriceps strength between the two legs before returning was linked to a lower rate of re-injury.[6]
Mental readiness matters too. Feeling confident in your knee, and not being held back by fear of another injury, is part of a successful return. People who go back to sport tend to score higher on questionnaires about psychological readiness, even when their knee function scores are similar to those who don’t.[7] A short questionnaire about confidence is often part of return-to-sport testing.
It also helps to have realistic expectations. In a large review of about 7,500 people, 81% returned to some form of sport after ACL reconstruction, 65% returned to their previous level and 55% returned to competitive sport.[8]
What changes if you also had a meniscal repair?
The menisci are the two cartilage cushions inside the knee. If a torn meniscus was repaired during your ACL reconstruction, the early stage of your rehabilitation is more protective to give the repair time to heal.
- Weight bearing: for 6 weeks you use two crutches and put only partial or no weight on the leg. Dr Vishal Pai will tell you which applies to your repair.
- Deep squats: avoid deep squatting for 4 months.
After this protected period, your rehabilitation follows the same stages as above.
Summary
Recovery after an ACL reconstruction is a gradual process that takes about a year, and it is guided by milestones rather than dates. Getting your knee straight early, building strength steadily, returning to running and jumping step by step, and being physically and mentally ready before you go back to sport are the main steps. Your own timeline may be faster or slower than the guide above.
If you would like to discuss how this applies to your knee, you can book a consultation with Dr Vishal Pai.
References
Show all 11 referencesHide references
- van Melick N et al. 2016. Evidence-based clinical practice update: practice guidelines for anterior cruciate ligament rehabilitation based on a systematic review and multidisciplinary consensus. British Journal of Sports Medicine.
- Noll S et al. 2015. Knee extension range of motion at 4 weeks is related to knee extension loss at 12 weeks after anterior cruciate ligament reconstruction. Orthopaedic Journal of Sports Medicine.
- Scholes C et al. 2023. Persistent knee extension deficits are common after anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomised controlled trials. Knee Surgery, Sports Traumatology, Arthroscopy.
- Salem HS et al. 2021. Return to driving after anterior cruciate ligament reconstruction: a systematic review. Orthopaedic Journal of Sports Medicine.
- Rambaud AJM et al. 2018. Criteria for return to running after anterior cruciate ligament reconstruction: a scoping review. British Journal of Sports Medicine.
- Grindem H et al. 2016. Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study. British Journal of Sports Medicine.
- Xiao M et al. 2022. Patients who return to sport after primary anterior cruciate ligament reconstruction have significantly higher psychological readiness: a systematic review and meta-analysis of 3744 patients. The American Journal of Sports Medicine.
- Ardern CL et al. 2014. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. British Journal of Sports Medicine.
- Carter H et al. 2020. The effectiveness of preoperative rehabilitation programmes on postoperative outcomes following anterior cruciate ligament (ACL) reconstruction: a systematic review. BMC Musculoskeletal Disorders.
- Li Z et al. 2025. Effects of neuromuscular electrical stimulation on quadriceps femoris muscle strength and knee joint function in patients after ACL surgery: a systematic review and meta-analysis of randomized controlled trials. Orthopaedic Journal of Sports Medicine.
- Gopinatth V et al. 2024. Blood flow restriction enhances recovery after anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomized controlled trials. Arthroscopy.
Frequently Asked Questions
Can I do anything before surgery to help my recovery?
Yes. Dr Vishal Pai usually recommends a short period of physiotherapy before surgery, often called prehabilitation, to settle the swelling, get your knee moving fully again and rebuild thigh strength. In a review of randomised trials, exercise programmes before surgery led to a small improvement in thigh strength and hop tests 3 months after the operation, although the studies were small.[9] Sometimes earlier surgery is needed, for example if you have an unstable meniscal tear that could be repaired.
When will my knee feel back to normal?
It varies from person to person. Bruising usually fades within 2 to 3 weeks, while some swelling can come and go for 3 to 6 months. The knee often keeps improving for 12 to 18 months after surgery, so it is normal to still notice it at times during the first year, especially after harder sessions.
Is it normal for my knee to swell after exercise?
Yes. Some swelling is common and can come and go for 3 to 6 months after surgery. If your knee is more swollen or sore the next morning, ease back for a few days and let your physiotherapist know. Sudden swelling with redness, warmth or a fever is different, and you should contact the rooms straight away.
Will electrical stimulation or blood flow restriction training help?
These are optional extras that your physiotherapist may suggest. In trials, adding electrical muscle stimulation to rehabilitation improved quadriceps strength, especially when it was started in the first week.[10] Blood flow restriction training, where a cuff partly limits blood flow to the leg while you lift light weights, improved strength and pain scores in trials.[11] Neither replaces a well-run exercise programme.
How often will I see a physiotherapist?
Most people see their physiotherapist regularly throughout the year, more often in the early months, and do a home or gym programme between visits. Your physiotherapist adjusts the plan as you reach each stage’s goals. If you live outside Bayside, including in regional Victoria, the rehabilitation plan can be shared with a physiotherapist near you.
Planning your rehabilitation after ACL reconstruction?
Dr Vishal Pai’s practice includes sports knee surgery, including ACL reconstruction and meniscal repair. If you would like to talk through what recovery could involve for your knee, you can arrange a consultation.
Written by Dr Vishal Pai
Vishal is an experienced knee surgeon based in Bayside, Melbourne. He consults at Sandringham Orthopaedic Specialists and operates at The Avenue Hospital and Calvary Holmesglen Private Hospital. His practice focuses on sports knee surgery, including ACL reconstruction and meniscal repair, as well as robotic knee replacement.