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The three things you want in a surgeon 


  1. That he can do your operation well 
  2. That he can talk to you in a way that makes you feel comfortable and confident
  3. Most importantly, that he exercises good judgement about what is the best treatment for you at any given time. 

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Knee Topics


MRI (Magnetic Resonance Imaging)

First Aid
How did it happen?
    Gave way
     Fell on to knee or hit knee

Does the knee swell up?
Where is the pain?
     In the front
     In the inner side
    In the back of the knee
     All over
When is the pain?
    Stairs and sitting
     Getting going
     Jams anytime
What kind of pain is it?
     Sharp, catching pain
     Aching and/or throbbing
     Burning pain
How did the pain start?
     Suddenly out of the blue

Basic Knee Anatomy

Other/Miscellaneous problems in and around the knee

    Baker’s cyst (also Popliteal cyst)
     Osteo-Chondritis Dissecans
     Osgood Schlatter’s disease
     Patella tendonitis
     Pre-Patellar bursitis
     Pigmented Villo-Nodular Synovitis (PVNS)
    Tibio-Fibular joint synovitis/arthritis

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Magnetic Resonance Imaging involves being placed in a large donut shaped electromagnet for up to 30 minutes, to obtain amazingly detailed images of not only the bones, but also the joint surfaces and cartilages, and the ligaments, and even inflammation within the bone. It can be very noisy and claustrophobic for some people, but more modern machines are a bit more open. People with certain metal or electronic implants are not be allowed to have an MRI, and you will asked questions about that beforehand.


First and foremost, what is needed is good first aid:
 R   Rest                       )
 I    Ice                         ) to minimize further internal bleeding
 C  Compression           )
 E   Elevation to reduce swelling
 R   Referral (to a good physio, &/or sports doctor, and maybe an orthopaedic surgeon)

Often the mechanism of injury is enough to strongly suspect the diagnosis, especially in typical cases of rupture of the ACL (Anterior Cruciate Ligament). It is then important to get the diagnosis confirmed or otherwise, and get expert advice on the best course of action.

The following is a simple rough guide to what damage may have been done:

How did it happen?
 • Gave way on landing or side-stepping: 90% chance you have torn your ACL (Anterior Cruciate Ligament).
 • ‘Snap’, ‘Crackle’ or ‘Pop’ in the knee when your knee went: 90% chance you have torn your ACL.
 • Rapid swelling after the injury, within hours, indicates bleeding within the knee (haemarthrosis). Sometimes it may be delayed till overnight, especially if the knee was iced after injury, and if the injury was late in the day: 70% chance you have torn your ACL. Alternatively you will usually still have had a significant injury, but very occasionally it may just be bleeding from acute impingement of some joint lining (synovium) with no serious damage.
 • Twisted and felt knee go out of joint: Maybe the patella dislocated and went back in. (Pretty obvious if it didn’t go back in!)
 • Twisted and felt pain on the inner side of the knee: Maybe a torn meniscus (cartilage), or maybe a sprained medial ligament. Or maybe just aggravation of some wear and tear, or impingement of some sensitive joint lining (synovium).
 • Jarred or twisted and felt pain on the outer side of the knee: Maybe a torn meniscus (cartilage), but again, maybe just aggravation of some wear and tear, or impingement of some sensitive joint lining (synovium).
 • Twisted and/or squatted, and haven’t been able to straighten knee properly since then (locked knee): Probably a torn meniscus (cartilage) has jammed out of place in the knee. (Sometimes it can click back in, but come out again from time to time.) Or maybe a loose bit of bone or gristle (articular cartilage), that is floating around like a mouse in the joint, could have jammed between the bones. There is a particular condition called Osteo-Chondritis Dissecans in which a piece of the joint surface can become detached and become a loose body in the knee.
 • Fell on to the knee: Probably painful bruising of the front of the knee, and if that involves the very sensitive pad of fat in the knee under the knee-cap, it can very sore for a long time (eg about 5 months). Maybe a tear of the Posterior Cruciate Ligament.
 • Major injury, like a motor bike accident; not sure of the mechanism exactly: Maybe a dislocation of the whole knee joint with rupture of several ligaments and tendons, with a risk of injury to the main artery that goes down the leg, and/or nerve damage.

To further clarify the possibilities, you should have X-Rays and then you will need an expert to examine your knee, to check if the ligaments are intact, and whether there is tenderness localized to a particular anatomic site, and whether there are signs of meniscus damage, or of the patella having dislocated. Quite often an MRI (Magnetic Resonance Imaging, in a big doughnut shaped electro-magnet) will need to be ordered to further clarify the exact diagnosis, in order to make the best informed decision on the best course of management, for your knee in your circumstances. 



The following is a guide to trying to make your own diagnosis, but can’t be relied upon without an expert checking your knee. Also, things don’t always quite fit the usual pattern, or you may have some symptom not listed here. Sometimes even the experts can’t put their finger on the problem right away, and X-rays may have been unhelpful, in which case an MRI is an excellent way of investigating further without harming the knee at all. 

Does the knee swell up?
 • There must be something significantly wrong, even if it is not terribly painful.

Where is the pain?
• In the front of the knee: Probably from the kneecap area. See patello-femoral pain.
 • In the front inner (antero-medial) aspect of the knee: Probably patello-femoral (kneecap) pain rather than a cartilage tear.
 • On the inner side (medial) of the knee: Probably cartilage tear or breakdown. Maybe the pain comes from the kneecap area.
 • On the outer side of the knee: Maybe (50-50) a tear or breakdown of the cartilage (lateral meniscus), but could also be pain from the kneecap area.
 • In the back of the knee: Maybe this comes through to the back of the knee from the kneecap area; maybe there is swelling in the back of the knee (Baker’s cyst), or, unusually, it could be atypical pain from a cartilage tear.
 • On both sides of the knee: Nearly always patello-femoral pain.
 • All over the knee; Maybe inflammation of the joint lining (synovitis), and often associated with swelling. Maybe patello-femoral.

BEWARE: pain in or around the knee may also come from somewhere else (referred pain or radiating pain). eg, thigh, hip, tight muscles, sciatica.

When is the pain?
• Mainly with going up and down steps, and/or with sitting or driving for a long time: Almost certainly this pain comes from the knee-cap area. (Patello-femoral pain)
 • With twisting or sideways movements: Maybe a torn cartilage, or maybe just joint lining (synovial) pinching.
 • With squatting down: Pain in the front is almost certainly patello-femoral. Pain on the side may be a cartilage tear, especially if it feels like there is something mechanically not right in there.
 • With time on my feet, standing and/or walking too long: Probably the pain is from the weight-bearing compartments, and may be due to arthritis.
 • Just walking along, the knee can suddenly partly give way, maybe with a sharp twinge of pain: This is usually due to some inflamed joint lining pinching between the knee-cap and the bone, causing the quads (the driver/thigh muscle) to quit for a split second. Usually people catch themselves before falling right down, but not always.
 • With first getting going from rest: This is the typical pain of inflammation, which is usually secondary to an underlying cause such as wear and tear, but can happen by itself for no good reason. This pain also eases when warmed up, but is worse at the end of the day and after activity, and especially at night.
 • Any time, even in the middle of the night, the knee gets severely painful and I can’t move it: This is usually due to inflamed synovium jamming between the knee-cap and the edge of the groove (femoral trochlea).
 • Especially at night: Aching is probably inflammatory, probably due to arhritis, but could be referred from higher up the limb, or from the hip or back.
 • When I rest my knees together: Strongly suggests cartilage damage, or maybe arthritis in the inner half of the knee (medial compartment).
 • All the time: This may on occasion be a cause for more serious concern, as it may be some sort of nerve pain, or pain referred from further up the leg. On the other hand, it may be inflammation pain, as above.

What kind of pain is it?
• Sharp, catching pain: This suggests there is something that is mechanically not right, such as a cartilage (meniscus) tear, but it could just be pinching of inflamed joint lining.
 • Aching and/or throbbing: Probably this kind of pain is due to inflammation, or arthritis, or both. The question is to sort out what is the underlying cause of the inflammation?
 • Burning pain: sometimes burning may be due to the heat in an inflamed joint, but often such pain suggests nerve pain, such as can develop in association with disturbance of circulation. If that is the cause, it may be a very difficult problem (eg Chronic Regional Pain Syndrome) needing expert help from a specialist in chronic pain management.

How did the pain start?
• Out of the blue, gradually sneaking up on me: Probably some sort of degenerative breakdown process affecting the joint surface and/or a cartilage, even if you are too young for that sort of thing.
 • Out of the blue, quite suddenly one day: The same underlying degenerative breakdown process, but with a bit of loose cartilage or meniscus spontaneously shifting and getting in the way. In young people there could be a bit of bone that has come loose, especially if the knee is clunking or locking.
 • With an injury: See “Acute Knee Injuries” also.

Basic Knee Anatomy:

The knee is the largest joint in the body. The knee joint is made up of the femur, tibia and patella (knee-cap). All these bones are lined with articular surface cartilage. This articular cartilage acts like a shock absorber and allows a smooth low friction surface for the knee to move on.

Between the tibia and femur lie two floating wedge-shaped shock-absorbing cartilages called menisci. The medial (inner) meniscus and the lateral (outer) meniscus are attached at the front and back ends and around where they attach to the joint capsule, but are stilll quite mobile, especially the lateral one. The menisci spread the load more evenly between the rounded femoral surface and the flatter tibial surface. The knee is stabilized by ligaments that are both in and outside the joint. The medial and lateral collateral ligaments support the knee from excessive side-to-side movement. The internal ligaments are the anterior and posterior cruciate ligaments which control the fore and aft movement of the tibia on the femur. If the posterior cruciate (PCL) is lax, the tibia drops back and there is more pressure on the knee cap, but not usually a feeling of instability. But when the anterior cruciate (ACL) is torn, it can feel like the knee can just gives way with certain movements.

The knee joint is surrounded by a capsule, and that is lined with a thin layer of synovium, which produces synovial fluid which is both nourishing and lubricating to the joint surfaces, to help with smooth motion. The thigh muscles are important secondary knee stabilizers, especially for the patella, to keep it tracking properly  in the trochlea groove on the femur.


Other/Miscellaneous problems in and around the knee

Baker’s cyst (also Popliteal cyst)
 Osteo-Chondritis Dissecans
 Osgood Schlatter’s disease
 Patella tendonitis
 Pre-Patellar bursitis
 Pigmented Villo-Nodular Synovitis (PVNS)
 Tibio-Fibular joint synovitis/arthritis

Baker’s (Popliteal) cyst

Sometimes there is swelling mainly in the back of the knee, and it may even be the first thing you note that is wrong with the knee. The cause is whatever is causing the synovitis and production of excessive synovial fluid within the knee. Generally, once that underlying cause is identified and fixed, the Baker’s cyst goes away by itself. Very occasionally, the cyst may have become so big and thick that it can’t resolve, and that it continues to cause sufficient trouble for it to be surgically removed. That requires a fairly small open operation, but it cannot be done with just an arthroscopy.

Osteo-Chondritis Dissecans

This is an unusual condition that develops in the last few years of growth, and is thought to occur because a small segment of the joint surface loses its blood supply long enough, or repeatedly enough, to become separated from the main body of the bone. The joint surface (articular cartilage) remains intact for a few months to several years, but when it splits around the margins of the lesion, the fragment of bone and articular cartilage separates and becomes an osteo-chondral loose body. This may click and cause discomfort and/or swelling. It may also dislodge and get jammed between the bones causing episodes of locking.
 The treatment is either to replace the fragment back in the crater it came from, and try to get it to heal, or if it is thought that is not going to succeed, or has already failed, then to just remove the loose body. That still leaves the question of the crater. If it is quite small, no further treatment may be necessary. If, on the other hand, the remaining crater is large enough to cause ongoing symptoms, or if it is lie that early arthritis will result, then it is desirable to find another way of trying to heal the defect. The most popular technique these days is to take some of the healthy articular cartilage from the joint, culture it in the lab for about 6 weeks, and then do what is called an Autologous Chondrocyte Impantation (ACI). If, as is usually the case these days, the graft comes on a collagen patch (matrix), then it is called Matrix Autologous Chondrocyte Impantation (MACI).

Osgood Schlatter’s disease

Not really a “disease” at all, this an over-use condition of the knee that occurs in kids whose skeleton has not yet matured. The over activity puts excessive load through the patella tendon, going from the knee-cap to the top of the shin, resulting in a traction injury to the growing bone at that point. The result is pain with and after activity, and tenderness right at that spot (the Tibial Tuberosity), and often the bone is slightly lifted up resulting the development of a permanent lump. The pain usually resolves by itself with reducing activity, and finally when the kid stops growing. Sometimes however, by that stage, a small fragment of bone may have become separated, forming an ossicle in the attachment site of the tendon, and where that attaches to the main bone may become a source of ongoing pain with activity. In that case it is called unresolved Osgood Schlatter’s disease, and it may be worth excising the ossicle. There will still be a lump though, because of residual scar tissue.

Patella Tendonitis (also called Jumper’s knee)

This the over-use condition affecting the patella tendon, going from the knee-cap to the top of the shin, that occurs after skeletal maturity, as opposed to Osgood Schlatter’s disease (above), which occurs in youngsters. The pain occurs at the top end of the tendon, at the lower end (inferior pole) of the knee-cap, and is due to micro-tearing of some of the deeper fibres of the tendon where they attach. Treatment is usually successful with physiotherapy, focussing on stretching exercises for the quads and hamstrings, machine and massage treatment to the site of pain, and anti-inflammatories and some rest to get the pain to settle initially. Sports doctors can often help with different treatments aiming at increasing the blood supply and healing potential of the micro-tear. Cortisone injections and even surgery may be required if all else fails.

Other/Miscellaneous problems in and around the knee

Baker’s cyst (also Popliteal cyst)
Osteo-Chondritis Dissecans
Osgood Schlatter’s disease
Patella tendonitis
Pre-Patellar bursitis
Pigmented Villo-Nodular Synovitis (PVNS)
Tibio-Fibular joint synovitis/arthritis

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Pre-Patella bursitis (house-maid’s knee)

There is a thin lubricating sack that allows the skin over the front of the knee to glide over the surface of the knee-cap. If that gets inflamed and swollen, it looks like the knee itself is swollen, and sometimes red, but on closer inspection, there is no excess fluid in the knee itself. All the swelling is in front of the knee-cap, and can cause trouble with kneeling, and with wearing trousers that rub over the area. In the early stages this can settle with anti-inflammatories and avoidance of aggravation. The next step would be a cortisone injection, and if all else fails, and it is giving a lot of trouble, then the swollen bursa can be excised.

Pigmented Villo-Nodular Synovitis (PVNS)

This is a rare and strange condition in which the synovium (soft joint lining inside the capsule) becomes severely inflamed, and can be very lumpy (nodular) or diffuse (villous) or both. It may be throughout the knee (or any other joint), or localised to one small area. It can be very aggressive and grow into bone, and grow back when it has been excised. Despite that, it is not a form of cancer, and does not go anywhere else in the body. If it is an isolated nodule, it usually does not recur. If the diffuse type does recur, it may require some follow-up radiotherapy the next time it has to be excised.

Tibio-Fibular joint synovitis/arthritis

The Tibio-Fibular joint at the knee (there is also a tibio-fibular syndesmosis at the ankle) is a small and often forgotten joint on the outer side of the knee. It doesn’t do much really, except allow for some minor rotation of the fibular, which is the thinner of the two bones in the leg below the knee, the main purpose of which now seems to be for muscles to attach to. Although the joint is not functionally important, it often communicates with the knee joint, and occasionally can be a problem in its own right, with or without problems also occurring in the knee joint. If pain is particularly on the outer side of the knee, it is one of the possible causative factors. If the problems within the knee joint have been fixed, maybe with an arthroscopy, or maybe after a knee replacement, and lateral pain persists, it is worth getting it checked with a bone scan, or an MRI, or both. A cortisone injection may be enough to settle the joint down again, or at least give temporary relief. If the pain should recur after good initial relief, it confirms that that is the problem. If all else fails, the joint can be excised and/or fused, which usually solves the problem very well and permanently.

Other/Miscellaneous problems in and around the knee

Baker’s cyst (also Popliteal cyst)
Osteo-Chondritis Dissecans
Osgood Schlatter’s disease
Patella tendonitis
Pre-Patellar bursitis
Pigmented Villo-Nodular Synovitis (PVNS)
Tibio-Fibular joint synovitis/arthritis

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Links to other detailed information


All about Total knee replacement - TKR

 What is Arthritis?
 Do I need a Knee Replacement?
 Recovery time
 How can I put off a TKR?
 How old is too old or too young?
 Getting ready for the operation
 In hospital
 What are the risks of TKR?
 Blood clots
 Other adverse outcomes
 How good is a TKR?

What are the Treatment Options Before Knee Replacement?

Activity, weight reduction
 Pain relief
 Physiotherapy, knee support, walking stick
 Joint Lubricant
 Cartilage cell graft
 Partial knee replacement

Patello-Femoral Pain

Nature and Site of Pain
 Aggravating Factors
 Associated Synovitis
 Buckling / Giving Way

Causes of Patello-Femoral Pain
 Joint Surface Damage / Chondromalacia / Minor Kneecap Arthritis
 Joint Lining Inflammation (Synovitis) and/or Impingement
 Plica Problems
 Excess Lateral Pressure Syndrome/Patella Subluxation and Dislocation
 Other Causes

Treatment Options
 1. Activity Advice and Reassurance
 2. Medication
 3. Physiotherapy
 4. Cortisone Injection
 5. Arthroscopic Surgery

Patello-Femoral Instability and Mal-tracking

Symptoms and Causes
 1. Acute patella dislocation or subluxation
 2. Recurrent patella dislocation
 3. Recurrent patella subluxation
 4. Patella mal-tracking/Chronic subluxation

Treatment of Patella Instability
 1. Quadriceps Rehabilitation
 2. Avoidance of Risk Factors
 3. Knee support
 4. Patella RealignmentSurgery

a) Lateral release
 b) Distal Patella Tendon Transfer
 c) Medial Plication
 d) Reconstruction of the Medial Patello-Femoral Ligament (MPFL)


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