Knee Arthroscopy

The arthroscope has revolutionised modern orthopaedic surgery. Frequently referred to as `keyhole surgery’ it is now a skill that most orthopaedic surgeons have acquired by the end of their training. However, the use of keyhole surgery is not new, as long ago as 1806, a device known as the lichtleiter was used, the lichtleiter had two canals, one for the light, normally a candle, and the other a viewing tube. Throughout the 19th century all manner of devices appeared for looking into various parts of the human anatomy. In 1918 a viewing tube normally reserved for inspecting bladders was inserted into a knee joint by a Japanese surgeon – the arthroscope had been born.
 
An arthroscope is basically a cylinder with a lens at each end. Because this viewing tube is so delicate the device is sheathed by a cannula for protection.
 
Using a fibreoptic viewing system it is possible for light to be shone down the arthroscope in the same direction as the surgeon is viewing in order to illuminate the interior of the joint. Most arthroscopes used in knee surgery do not actually view directly ahead, but at an angle of 30 degrees from the line of the arthroscope. This allows a surgeon to look around corners – there are plenty of them in a knee. A camera is usually attached to the viewing end of the arthroscope and the image displayed on an adjacent television screen. Instruments can then be introduced into the knee through separate holes (surgical holes are sometimes called ‘portals’) so that tissue can be removed or repaired.
 
These instruments can be manually operated, or powered, radiofrequency, or even lasers.

What we do

The fact an operation is performed through small keyhole incisions does not mean it is simple. Indeed, there are some surgeons who, even to this day, find it difficult to master the art of endoscopic surgery.

Arthroscopy may be performed under local or general anaesthetic and is normally a daycase operation. That is, admission, operation and discharge all take place on the same day. For those coming from further afield, it may be necessary for admission to be the day before surgery, or discharge to be the day after.

Once in the operating theatre, the patient’s skin is prepared with a special antiseptic solution in order to kill the bacteria that live as commensals on all our skins. The leg is then draped with sterile drapes to seal off the operating area from the rest of the body and surgical staff who are not playing a direct part in the procedure.

Then, with a small knife, the surgeon makes a tiny incision (‘stab’ incision) just to the outer side of the patellar tendon (kneecap tendon). Through this incision the arthroscope is introduced, using a series of trocars through a metal cannula, no more than 5 millimetres in diameter. Once the arthroscope has been inserted, a further stab incision is made on the other side of the patellar tendon and through this portal an arthroscopy hook is inserted. The hook is an important instrument. It allows the surgeon to probe suspicious areas, to feel the strength of ligaments, or to reposition loose bodies so they can be more easily retrieved.

The surgeon then makes a thorough inspection of the knee joint, looking into every crevice possible, and then decides on the appropriate operation. This may be a meniscectomy (cartilage removal), or debridement (‘clean-out’ operation), ligament reconstruction, or any number of alternatives. The hook is then removed and more definitive surgical instruments inserted. These instruments may be manually operated, radiofrequency, laser-driven, or powered. The so-called ‘power shavers’ comprise rapidly rotating cutting blades, often with a diameter of less than 3.5 millimetres, that can both cut and suck at the same time. All the cut material is thus rapidly and automatically removed from the joint.

Once surgery is complete, the instruments and arthroscope are removed and the small portal wounds may either be left as they are to heal naturally or may be sutured, stapled, taped, or even glued!

Following discharge it is common for patients to feel discomfort, though not to a great level, for about four weeks. Those for whom osteoarthritis (OA) is the diagnosis can sometimes feel discomfort for longer. In a few cases of OA, pain can persist for several months. For the majority, however, after this four-week period, they are back to reasonable normality, although it can sometimes be up to a month for symptoms to fully settle.

It is common for the knee to be slightly swollen during this period. Sports can be resumed to a limited extent one month after surgery and physiotherapy is frequently encouraged for at least this period. However, it can be anything up to three months following arthroscopy before a knee has fully settled after a knee arthroscopy. On occasion it may take even longer to resolve.

In your postoperative course as an in-patient, which is approximately 3-5 days, you will be seen daily by either myself or my anaesthetist, by the physiotherapist and obviously you will be looked after by the nursing staff.  During that time, we aim to turn you from an anxious patient with a painful knee back into a reassured, pain-free 25-year-old (!) who will feel confident in going back into the outside world and taking up all your old hobbies, activities and sports.  I am proud to work at Southern Cross North Harbour and feel that the standard of care patients receive is exceptionally high and second to none.  The dedication of the nursing staff and allied health care professionals is exemplary and I would have every confidence in a member of my family going there for surgical or medical treatment.

Recovery from surgery once home

Different people recover at different rates. The final success of a knee replacement is many years of pain-free normal knee function.  To achieve this goal, it is necessary to do some rehabilitation and generally look after yourself.

  • It is important to walk every day, as this increases muscle, ligament and tendon strength. It will rebuild your muscles that will have become wasted as a result of the painful arthritis, and it will help to increase the density of your bone, preventing osteoporosis.
  • It is important to take good care of your skin, both on the operated site and around the rest of the body.  Your skin is a protective barrier against infection and any breach in this barrier could potentially allow infection into the blood supply, which may result in seeding of the infection in the artificial knee joint.  This in itself is likely to require a significant amount of further treatment (both surgery and medical treatment) to cure the infection.
  • Dental hygiene should be a high priority and any abscesses should be dealt with prior to knee replacement surgery.  Following knee replacement surgery, it is important that abscesses are treated promptly and comprehensively with antibiotics to stop infection travelling in the blood supply around to the knee joint.

Different people recover at different rates. The final success of a hip replacement is many years of pain-free hip function. To achieve this goal, it is necessary to do some rehabilitation and generally look after yourself.


  • It is important to walk every day, as this increases muscle, ligament and tendon strength. It will rebuild your muscles that will have become wasted as a result of the painful arthritis, and it will help to increase the density of your bone, preventing osteoporosis.
  • It is important to take good care of your skin, both on the operated site and around the rest of the body. Your skin is a protective barrier against infection and any breach in this barrier could potentially allow infection into the blood supply, which may result in seeding of the infection in the artificial hip joint. This in itself is likely to require a significant amount of further treatment (both surgery and medical treatment) to cure the infection.
  • Dental hygiene should be a high priority and any abscesses should be dealt with prior to hip replacement surgery. Following hip replacement surgery, it is important that abscesses are treated promptly and comprehensively with antibiotics to stop infection travelling in the blood supply around to the hip joint.
  • Most hip joints are designed to give you almost normal hip movement. However this is not a completely normal movement. There is one particular movement which should not be attempted as this may result in a dislocation (the ball coming out of the socket – extremely painful!). This position, WHICH SHOULD BE AVOIDED, is with the knee bent up and in, and the foot bent up and out. I will run over the safe and the unsafe positions with you both before and after surgery and if you ever have any concerns, just remember both knees and ankles together is safe.
  • Deep vein thrombosis/pulmonary embolism (DVT/PE) – blood clots in the veins in the legs or lungs
  • Neurovascular injury – damage to nerves or blood vessels
  • Infection – which can be superficial in the wound or deep in the new joint
  • Fracture – where the bone breaks around the knee joint
  • Myocardial infarct (heart attack) or CVA (stroke).
  • Stiffness – the importance of rehabilitation and physiotherapy
  • Leg swelling and stiffness – this always occurs to a greater or lesser extent and resolves over 4-6 weeks
  • Pain
  • Haematoma (an accumulation of blood around the surgical site that may require drainage.
  • Loss of blood during surgery that may require a blood transfusion.
  • Numbness, pain or itchiness around the scar.

Follow up

All patients who have had a knee replacement will be seen approximately 6-8 weeks after surgery in an outpatient clinic. Further questions can be answered and it is about this time that I tend to suggest an activity-based rehabilitation programme to increase peoples strength, fitness and stamina.

The recovery up to the 6-week mark is generally the same for most people and I would advise avoiding the gym or swimming for the majority of this time.


I would suggest that most patients have approximately 6 weeks off work, if still in employment, for very similar reasons to those given above for driving. It is important to rehabilitate and do the exercises that will be shown to you in hospital and also it is my experience that after this form of surgery, most patients are really quite tired for 3-4 weeks and require more sleep and rest than usual.

Obviously, each individual’s job should be taken into account and I can discuss this further with you when we meet up.

We do not know exactly how long an individual knee will last. It will vary, depending on the type of knee replacement (prosthesis), the surgical technique, the activity level of the patient, other patient factors (e.g. co-morbidities, obesity) and a little bit of luck.

When a knee replacement wears out, it is still possible in almost every case to revise the knee and put in a new knee joint. However, the complications and the risks associated with revision surgery are slightly higher than with surgery first time around. The long-term results are also slightly less predictable.

Frequently Asked Questions

There are a number of causes for knee problems. The most common is osteoarthritis (wear and tear, generally related to age). Rheumatoid arthritis is a condition whereby the lining of the joint becomes extremely inflamed and starts to destroy the healthy articular cartilage. A knee replacement is also called a, knee arthroplasty (the technical term). It can be a Total knee arthroplasty ( a whole knee replacement) or a Uni-compartmental knee replacement (half a knee replacement).

Its aim is to alleviate pain and provide a near-normal range of movement.


The decision for surgery should be made by the patient in conjunction with the orthopaedic surgeon. In the vast majority of cases, the decision should be made by the patient, only rarely should an orthopaedic surgeon persuade a patient to consider a knee replacement sooner rather than later (e.g. concerns that the bone is wearing out, which would mean that the surgical technique becomes significantly more difficult and this may result in a less successful outcome). 

Most patients deciding on surgery will be having pain on a daily basis. There is often a constant underlying baseline ache, which is made worse by certain movements, activities or positions (e.g. going for a walk, going up or down stairs, getting in and out of a car or trying to put on shoes and socks). In the first instance, simple pain relief such as Panadol may help with these symptoms.

Often patients who are able to take anti-inflammatory medication will find good relief of their symptoms and sometimes stronger painkillers, which are prescribed by a medical professional, will be required as the knee pain worsens. Quite often, the pain will get worse at night and may even keep people awake, or wake people up from sleep.Physiotherapy and various activities and movements, such as swimming, may also be beneficial to the joint and may help relieve some of the pain and stiffness. The stiffness typically makes it difficult to sit in a low chair, go up or down stairs easily, put on shoes and socks and paint or clip toenails / wash between the toes. 

Whilst painkillers and anti-inflammatory medication, exercise modification and walking aids, e.g. walking stick may help the symptoms, they will not cure the diseased knee. The knee will slowly deteriorate and it is at this point when non-operative measures have been tried and exhausted, most orthopaedic surgeons would recommend the consideration of joint replacement.

In some cases it may be best to replace both knee joints during the same operation. This tends to be in some patients who are confined to a wheelchair or who suffer from extreme stiffness or pain and think that rehabilitation after one may be made extremely difficult because of arthritis in the other knee.

Recovery and rehabilitation tend to be a little bit more difficult and uncomfortable in the first few weeks after surgery, but there is the advantage of less total time off work for recovery.

Surgery Locations

Southern Cross Hospital North Harbour & North Shore Hospital
My Clinic locations

 
Southern Cross Hospital
North Harbour
232 Wairau Rd
Glenfield

 
The Doctors Fred Thomas (Fred Thomas Health, Takapuna)
2 Fred Thomas Drive Drive
Takapuna

 

Silverdale Medical Centre
Silverdale
4 Silverdale Street
Silverdale

 
Kawau Bay Health Centre
Warkworth Cnr Percy & Anwick Streets
Warkworth

 
Westgate Medical Centre
Westgate Westgate Shopping Centre
Fernhill Drive
Massey