Recovery / Rehabilitation

It’s written several times in several places on various pages of this website, but …

A knee arthroscopy is not ‘just a knee arthroscopy’

No two arthroscopies are ever quite the same, and no two patients are ever the same…

Your rehab will depend on what’s done in your knee, which itself will depend on what’s actually found inside the knee when your arthroscopy is performed … it’s not uncommon for your surgeon to give you a ‘differential diagnosis’, which means a short list of possible diagnoses/issues that he is anticipating potentially finding inside the joint. One should always remember that MRI scans are only about 90+% accurate, not 100%, and MRI image/results should always be viewed in the specific context of the individual patient’s history, symptoms and clinical signs …

So, this is why it is difficult to predict accurately or too confidently exactly what a patient’s rehab is definitely going to be after a knee arthroscopy. Your surgeon will discuss all of these details with you in clinic, in advance of you being booked for any surgery. In addition your surgeon will come and see you on the ward in hospital directly after your operation, to tell you what he found inside your knee, what was done and exactly what your actual rehab is going to need to be.

Furthermore, actual ‘recovery’ from surgery also depends on many factors. Probability and percentage of recovery plus long-term outcome all depend on the extent of the potential damage in the joint, what is done inside the knee, the age of the patient and the functional aspirations of the patient, in terms of what job they do (office based vs manual), what exercise they do (super fit vs couch potato) and what level they might play at for sport (professional vs non-competitive amateur). Again, all of this needs to be discussed properly and carefully with your surgeon.

Just as ‘a knee arthroscopy is not just a knee arthroscopy’ and ‘a knee surgeon is not just a knee surgeon’, so –

a physio is not just a physio! 

Some insurance companies have put enormous undue pressure on physios over recent years, forcing them to charge almost unsustainably low fees against the threat of potential delisting … therefore, if you have medical insurance your choice of physiotherapist might potentially be restricted purely on cost, not QUALITY. However, the quality of your physio is key to your rehab and recovery.

Your surgeon should be able to advise you about who they feel the best local physios are … the decision as to whether to then entrust your knee and your outcome to the best physio or the cheapest physio is entirely up to you. Furthermore, some patients occasionally ask whether they could potentially have their post-operative physio rehab in the NHS after their surgery … as with most things in life, you get what you pay for! — to get NHS physio you will first need to try and get an appointment with your GP (good luck!). Then, you’ll have to explain your situation to your GP and ask them politely to do you a physio referral. Then, your referral will go on a waiting list. When you can get a slot for your physio sessions (however long that might take), you will then have no choice over who your physio will be, and no guarantees as to the experience, seniority and abilities of the physio that you will see. You will now be on a target-driven tick-box clipboard-audited conveyor belt that actively pressurizes physios into discharging patients as quickly as possible, with as few treatment sessions as possible. Again, if you feel that this is what you want … then good luck!

I am not personally a fan of specific, didactic, time-based, rigid fixed ‘protocols’ for rehab …. as every patient and every case is different, and a patient’s rehab should be tailored to their pathology, the specific treatments that they’ve received, and also to their needs, demands and personality. This is why I favour guidelines, and why it’s so important that your rehab is appropriately supervised by a decent and safe physio, as then one can follow more of a goals-based approach.

For any operation bigger than a minor arthroscopy, and for any procedure where one would normally anticipate significant or prolonged knee pain, swelling or stiffness, I strongly recommend the use of the GAME READY system. This is a fantastic new system that patients can rent for 1 month or more for use after their surgery that allows cooling and intermittent compression of the joint, and which reduces pain, reduces swelling, reduces the number of painkillers one needs to take and which speeds up early rehab.

As a rough guide only, below I have listed some of the more common arthroscopic procedures that can be undertaken in the knee, with guidelines for the appropriate rehab that might be required after each:-

  • Arthroscopy and trimming of a meniscal tear (partial meniscectomy)
  • Meniscal Repair
  • Microfracture
  • Articular cartilage grafting
  • ACL reconstruction
  • Meniscal transplantation or meniscal scaffolds



Partial meniscectomy

The first few days

Most patients who have a meniscal trim will need crutches post-op for just a couple of days, simply for comfort and confidence. The hospital physios will see you on the ward after your operation, before discharge, to show you how to use the crutches and to give you general advice about what gentle exercises to do for the first week or so prior to you being seen back in clinic for review.

The first week

I advise patients generally to take 1 week off work so that they can rest and take things easy. You should not just sit/lie around and do nothing (because of the potential risk of DVT associated with immobility). Instead, you should ‘potter around’ lots and keep yourself moving, but you should avoid long walks or any kind of proper exercise during this initial ‘healing’ period. If you try and do too much then your knee might become a bit swollen and painful, in which case you’ll need to rest the joint, ice it, elevate your leg and potentially take some anti-inflammatories.

Post-op clinic appointments

I tend to see my patients back in clinic at about 10 days post-op, to check their knee, remove any dressings/stitches/steristrips, to go through the details of the operation with the patient, to show them the pictures and video of their operation and then give them copies of everything (including the operation video) for their personal records. Patients are normally then ready to start their physio rehab.

Physio rehab

The number and frequency of physio rehab treatment sessions that you might need will depend on how bad your knee is and how quickly the joint recovers. Your physio will therefore need to assess you initially, before then putting together a treatment plan for you. Most patients are seen by their physio 2 or 3 times a week for the first few weeks, after which most patients are then ready to continue on their own with the exercises that they’ve been taught.

Most people after a simple partial meniscectomy have recovered pretty much fully by about 6 weeks post-op.

Meniscal repair


One of the biggest difficulties with meniscal repair is the uncertainty over which tears might actually be repairable (which can only really be determined intra-operatively, at the time of the actual arthroscopy, when the meniscus is inspected and probed carefully). The other main issue is the relatively slow rehab that is often required afterwards.

Every meniscal tear is different, and every repair is different. If a meniscal tear is small and fairly stable, and if in these instances I am confident that a meniscal repair is solid, strong and stable enough, then occasionally I might not significantly restrict a patient post-operatively, and I might simply advise that they should be fine to follow a rapid rehab regime, along the lines of that for a meniscal trim.

However, in many cases, the meniscal tear is larger and/or less stable. Meniscal sutures are tiny and tend to be somewhat delicate, plus the meniscal tissue can itself often be quite delicate or friable. Therefore, more often than not I will protect a patient’s knee after a meniscal tear and advise slow careful rehab.

Phase I: First 6 weeks post-op

I will often advise that patients remain partial or very occasionally even fully non-weight bearing with 2 crutches for the first 6 weeks. During this initial period, we often also keep the knee in a strap-on hinged knee brace, specifically to prevent too much flexion of the knee (which can overload the repaired meniscus). If I feel that the meniscal repair is very delicate then I might lock the brace so that the knee can straighten fully but so that flexion is limited to a maximum of 45o. If I have greater confidence in the strength of the repair then I might limit flexion to just 90o.

At the end of the first 6-week period, the knee will be stiff, the muscles will be wasted and weak, the proprioceptive reflexes in the knee will be lost and you are likely to have lost a lot of your general cardiovascular fitness.

Phase II: From 6 weeks to 3 months post-op

The second phase of the rehab therefore involves regular (2 or 3 times a week, initially) intensive physiotherapy rehab treatments, focusing initially on:-

1)   regaining the full range of motion in the knee joint ASAP,

2)   regaining the muscle strength, and

3)   retraining the proprioceptive reflexes (the muscle reflexes).

However, during this second 6-week period it is important that you still avoid any:-

ø      deep loaded squats

ø      lunges

ø      heavy weights

ø      impact (jumping, running)

ø      twisting on the knee.

Phase III: from 3 months post-op

By 12 weeks (3 months) post-op, most patients are ready to start the final phase of their rehab, which involves starting gentle jogging on a treadmill, gradually building up speed and time/distance. The next step is to try running outdoors and then pivoting/cutting manoeuvers (under supervision of your physio), before then going back to sport-specific training – and actual return to sport should only commence once your physio has given you the all clear, which will be when they feel that your strength, reflexes and general neuromuscular control is actually good enough.




With microfracture, areas of missing articular cartilage on the joint surface, with bare bone exposed, are treated by puncturing small holes through the bone surface. This allows blood from the bone marrow, which is rich in stem cells, to form a clot covering the area of the cartilage defect, and with time (and appropriate protection) this clot matures into ‘fibrocartilage’. Fibrocartilage is half way between new cartilage tissue and scar tissue, and although it is not as good as proper articular (hyaline) cartilage, it is much better than just exposed bare bone in the joint.

Rehab after microfracture is aimed at protecting the area of the joint surface where the microfracture has been performed, to give the blood clot the best possible chance of healing and maturing successfully into fibrocartilage. The best way to do this is to try and minimize loading on the affected area and shear forces. The rehab will therefore vary according to the part of the joint affected.

Phase I: First 6 weeks post-op

If the area of microfracture is on the main weight bearing surface of the joint then I tend to keep my patients minimally (toe-touch) partial weight bearing with 2 crutches for the first 6 weeks post-op. During this period I may or may not also recommend a knee brace, to restrict the range of motion of the knee.

By the end of the first 6-week period, your knee will be very stiff, the muscles weak and wasted and you will have lost your reflexes around the knee and your general cardiovascular fitness.

Phase II: 6 weeks to 12 weeks (3 months) post-op

The second 6-week period is ‘Phase 2’ of the rehab, and during this period you will need regular (ideally 2 or 3 times a week) treatment sessions with your physiotherapist plus regular work on your own, in between, performing the exercises that you will be taught. This period is all about getting the full range of motion back in the joint ASAP, and slowly and carefully getting some muscle strength and reflexes back.

Phase III: 3 months post-op onwards

From 12 weeks (3 months) post-op onwards, is all about regular gym work, working hard on getting back your general fitness but without over-stressing the joint.  I normally recommend that people wait a full 9 months before doing any:-

–       deep loaded squats

–       lunges

–       loaded twisting/pivoting on the joint

–       impact (eg running, jumping)

This is to give the healing microfracutred area the best possible chance of maturing nicely and giving a good long-term result. Therefore, Phase 3 should be all about doing regular:-

–       walking

–       exercise bike and cycling

–       cross-trainer

–       swimming (particularly with front crawl / freestyle legs)

If you try and focus on building up muscle bulk during this rehab then you will be loading the joint heavily, which may damage the microfractured area. Therefore, instead, you should focus primarily on fitness training, as this will stress the joint less than direct strength training, and you will regain muscle bulk more slowly but more safely.

The success rate of microfracture is that about 80% of patients have a good to excellent result when reviewed 5 years later (this does not mean it takes 5 years to reach your final outcome/recovery!). However, the results rely enormously on patients following the appropriate rehab, which is as important as the actual surgery itself. So, if you can’t (or are not prepared to) follow the rehab advice closely, then it’s probably best to avoid having the surgery.

Microfracture in the patellofemoral joint

One variation of the above rehab regime is where microfracture is performed in the patellofemoral joint (either on the back of the patella (kneecap) or in the trochlear groove, at the front of the knee). When the knee is straight (fully extended) the patella sits above the trochlear groove. It enters the trochlear groove at about 20 or 30 degrees of knee flexion. Thus, the patellofemoral joint is specifically loaded when the knee is in a bent position (eg squats, leg press or kneeling), and it is relatively unloaded when the knee is kept straight.

Phase I: First 6 weeks post-op

Therefore, if microfracture is performed in the patellofemoral part of the knee joint, then I often keep my patients in a knee brace locked at 0 to 20o flexion for the first 6 weeks (just to allow a little movement). However, it is safe to weight bear (which loads mainly the tibiofemoral compartment of the knee joint), although I still advise patients to use crutches for the first 6-week period, whilst the knee brace is on), but this is for stability/safety and not specifically to keep weight off the knee.

Phase II onwards

From 6 weeks post-op onwards the rehab is then the same as it would be for microfracture in any other part of the joint, although because the knee has been kept relatively straight so far, the joint will be even stiffer and it will take even more work early on to get the range of motion back in the knee.


Articular cartilage grafting


Microfracture works best with smaller cartilage defects that are well contained (ie a good shoulder of healthy stable surrounding tissue). For cartilage defects greater than about 2cm2 microfracture tends to be less effective/appropriate, and the bigger the surface area involved the worse the outcomes. Therefore, for articular cartilage defects significantly greater than 2cm2 I normally recommend the use of a Chondrotissue Articular Cartilage Graft.

With Chondrotissue grafting, the edges of the cartilage defect are tidied up and stabilized and the base of the defect is cleaned and then microfractured extensively. The bare area is then covered over with a bioabsorbable porous scaffold, like a sheet of sponge, which is glued in place with a bioabosorbable glue (made from fibrin, which is what makes blood clots stick). Blood, bone marrow and stem cells are drawn into the sponge-like membrane, and as the cells mature into new cartilage-like tissue, the membrane is gradually absorbed away.

The rehab after Chondrotissue articular cartilage grafting is in 3 phases:-

Phase I: First 6 weeks post-op

For the first 6 weeks we protect the knee joint, specifically to protect the Chondrotissue graft from heavy loading, impact or shear forces.

Therefore, for the first 6 weeks I keep patients minimal-weight-bearing on 2 crutches and in a hinged knee brace. The knee brace is initially locked, to allow flexion from just 0 to 20o only.

During these early stages, it can be useful to see your physio for maybe just a couple of sessions, just for general advice.

Phase II: 6 weeks to 12 weeks post-op

During this second 6-week period, we really get the knee moving, and this is where you will need to see your physio regularly (ideally 3 times a week) for intensive physio treatment sessions. The aim here is to:-

–       regain the full range of motion in the joint ASAP

–       build up to full weight bearing as soon as comfort, strength and confidence allow

–       start gentle muscle strengthening and proprioceptive reflex re-training (the muscle reflexes)

–       start using the exercise bike on low resistance as soon as the knee joint range of motion is sufficiently good.

Phase III: From 12 weeks (3 months) post-op onwards

From 12 weeks (3 months) post-op onwards most patients are ready to cut down on their physio treatment sessions and instead start spending more of their time simply in the gym, specifically doing the exercises that they have been taught by their physio, with perhaps just occasional visits back to the physio for general guidance. However, it is vital not to overload the knee while the cartilage graft is still healing, ‘bedding in’ and maturing. Therefore, I advise patients that they should avoid the following:-

ø      no deep loaded squatting

ø      no lunges

ø      no heavy weights eg leg press

ø      no loaded twisting on the knee

ø      no impact (running, jumping etc)

Instead patients should focus on regaining their cardiovascular fitness, and the muscle strength will simply come back with time, secondary to that, and the ideal exercises to focus on are:-

–   the cross-trainer

–   swimming with front crawl legs only

–  walking (but avoiding hills and uneven ground)

–  cycling outdoors, but avoiding off-road mountain biking

–  exercise bike (with the seat as high as possible), but avoiding heavy spinning classes

By 9 months post-op, the knee has probably recovered as much as it is likely to.

In the longer term, from 9 months post-op onwards, whether or not you should return to full normal sporting activities is a difficult decision that is very much down to the individual … If your knee has healed up well and if it feels good enough, and if there are certain sports that you really love, then even though impact/pivoting type sports such as football, squash, tennis, badminton, basketball, netball etc are all actually bad for the knee joint, life is short and you might simply decide to return to sport regardless. Otherwise, if you want to protect your knee joint as much as possible then you might decide to stick to the ‘knee friendly’ exercises/sport instead, such as swimming and cycling. This is a difficult issue that your physio will be able to give you further guidance on. However, generally speaking, by the time someone’s knee joint is bad enough to justify articular cartilage grafting then it’s normally sensible to protect the joint from that point onwards, to try and reduce further wear and tear and avoid or delay the potential future onset of arthritis and the need for further bigger surgery.


ACL reconstruction


It’s said by some that the rehab after an ACL reconstruction is more important than the surgery. That’s not actually true! I’ve seen many many ACL reconstructions that have been done ‘elsewhere’ done so badly that the patient has needed to have the surgery revised, and the most common cause for failure of an ACL graft is technical errors in how the actual surgery was performed (ACL reconstruction is a very technically challenging procedure that requires great understanding of the anatomy and biomechanics of the knee, great understanding of the science of ligaments, bone and fixation devices, and great surgical dexterity, skill and precision). By comparison, I’ve not yet ever seen an ACL reconstruction ‘fail’ because of inappropriate or insufficient physio rehab.

This is not to say that proper and intensive rehab after ACL surgery is not important … it is, and it can make a large difference to the rate of recovery of a patient and to the level of sports participation that they might be able to return to.

Rehab after an ACL reconstruction takes a full 9 months. This does not mean that you will be severely restricted for the whole period – far from it …

Phase I

The first week or two are tough, and are spent getting over the surgery / anaesthetic.

Patients are initially given crutches for comfort / safety. These can be discarded normally within just a few days, as soon as you feel comfortable, strong and steady enough.

The first 6-week period requires lots of physio input to get the movement back in the knee, the swelling down and some strength back. During this phase of the rehab you will need lots of direct hands-on input and assistance from your physio, and ideally you should see your physio 2 or 3 times a week during this period, continuing by yourself in between with the exercises that your physio will teach you.

Phase II

The second 6-week period is where a lot of the hard work is put in to really strengthen up the joint and get the reflexes back.  This requires regular sessions with your physio plus regular hard (but careful and controlled) work in the gym and exercises at home.

Phase III

By 3 months most people are ready to start gentle jogging on a treadmill.  From this point onwards you are likely to need less input from your physio, and most of your time should be spent in the gym focusing on gradually regaining your strength and fitness.

When your physio feels that you are ready, you will be advised to progress from gentle jogging on the treadmill to proper running. When your neuromuscular control is sufficiently returned then your physio will progress you onto cutting/pivoting manoeuvres and then into sport-specific training.

Far from being highly restricted throughout your rehab, during this 3rd phase of your rehab you should be going to the gym regularly, and most people state that by the end of their full rehab after an ACL reconstruction they’re actually fitter than they’ve ever been!

By 9 months post-op most patients are ready to return to full and normal sport. It should, however, be remembered that once any joint is injured (and particularly the knee joint) it is never going to be quite the same again … and after an ACL rupture there is a subsequent increase in the risk of developing arthritis in the knee in the future. Therefore, it is recommended that patients should have a serious think about exactly what sports and exercises might be best for their knee in the long-term and what they might wish to focus on, and your physio should be an ideal person to discuss this with, as should your surgeon (I give my e-mail address to every one of my patients, who are always told that they are welcome to get in touch with me anytime for queries or advice … if your surgeon isn’t doing the same then you should perhaps question the quality of the service that you’re receiving!)

ACL reconstruction with other concurrent procedures

It is not uncommon for there to be other concurrent damage inside the knee joint, as well as rupture of the ACL, and this will normally be dealt with at the same time as the ACL reconstruction. Therefore, if specific additional procedures such as meniscal repair, meniscal replacement, microfracture or articular cartilage grafting are also performed inside the knee, then your post-op rehab for your ACL is likely to be delayed for an initial period, as the rehab will always follow the regime of the most difficult/delicate procedure that needs the most protection for the joint.

For example, if a meniscal repair is performed at the same time as your ACL reconstruction, then you might potentially need to be on crutches with your knee in a hinged brace for the first 6 weeks before then commencing a standard ACL rehab regime. If, by contrast, a meniscal trim is required at the same time as an ACL reconstruction then this will not affect the ACL rehab, and a standard ACL rehab regime can simply be followed.


Meniscal transplantation


Meniscal replacement surgery is an extremely complicated and technically challenging subject, and the surgery should only be undertaken by highly specialized surgeons with a particular sub-specialist interest.

The surgical is difficult and ‘fiddly’, but normally only requires a single night’s stay in hospital post-op. The real issue for most patients is the very slow rehab that is required afterwards.

The rehab after meniscal replacement surgery is the same for scaffolds as it is for allograft transplantation, and is split into 3 phases. Phase I (the first 6 weeks) involves protecting the knee, to allow the scaffold or graft to heal into place. Phase II (from 6 weeks to 3 months post-op) is mainly about getting the movement back in the joint. Phase III (3 months post-op onwards) is about regaining muscle strength and reflexes but without over-stressing the new meniscal tissue), with most patients reaching their end point by 9 months post-op.

Phase I – First 6 weeks post-op

During the early post-operative period the knee is protected, specifically to allow the meniscal scaffold or allograft to heal around its periphery. I therefore keep my patients partial weight bearing with 2 crutches and with the knee in a hinged knee brace, initially locked at 0o (straight) to 45o flexion (bend). Patients normally stay in hospital for 1 night post-op, going home the day after their surgery, and I then normally review patients back in clinic approximately 10 days post-op. If at that stage everything is looking good enough, then we might adjust the brace to allow flexion up to 90o.

Whilst the brace is on, there are not really many exercises that you can do, and by the end of this first period the knee is inevitably going to be stiff and weak, with significant muscle wasting. There are some gentle exercises that you can do with the brace on, to prevent too much muscle wasting – such as static quads contractions and straight leg raising – and the hospital physio will have shown you these in hospital, prior to discharge.

Phase II: from 6 weeks post-op onwards.

At the end of the first 6 weeks the knee brace can be removed and you will then need to start regular intensive physio rehab treatments (ideally 2 or 3 times a week, to start with) to work hard on regaining the full range of motion in the joint ASAP.

After the first 6 weeks you will also be encouraged to start gradually increasing your weight bearing through the operated knee, building up towards full weight bearing and discarding the crutches as soon as you feel strong enough and confident enough, which normally takes a few weeks.

At the same time, your physio will help you work on gradually and carefully rebuilding the muscle strength and bulk in your leg, as well as retraining the proprioceptive reflexes.

Phase III: approx 3 months post-op onwards.

Whenever your physio feels that you are doing well enough, which for most people is by about 3 months, they will reduce the frequency of your appointments with them and you will then simply need to continue in the gym yourself with the exercises that they will have shown and taught you.

The new meniscal tissue does still need to be protected whilst it is ‘bedding in’ and maturing. Therefore for the first full 9 months after your surgery, you should avoid the following:-

ø      no deep loaded squatting

ø      no lunges

ø      no heavy weights eg leg press

ø      no loaded twisting on the knee

ø      no impact (running, jumping etc)

Instead you should focus primarily on regaining your cardiovascular fitness, and the muscle strength will simply come back with time, secondary to that, and the ideal exercises to focus on are:-

–   the cross-trainer

–   swimming with front crawl legs only

–   walking (but avoiding hills and uneven ground)

–   exercise bike (with the seat as high as possible), but avoiding heavy spinning classes

By 9 months, most patients tend to have recovered pretty well as much as they are likely to. The decision as to whether or not to then actually go back to any kind of impact/pivoting sport very much depends on how much actual damage there is in the joint, exactly what has been done inside the knee, the age of the patient, and many other factors – and this is something that you should discuss in detail and at length with your physio and with your surgeon, who will be able to give you specific guidance.


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Written by Mr Ian McDermott Consultant Knee Surgeon, London

Last updated 4-5-17