Knee Arthritis


Arthritis of the knee is a very common problem that affects over 10% of the adult population. It typically starts as a gradual onset of knee discomfort and pain when weight bearing. It can progress to a more constant background pain, present at rest and at night, occasionally interfering with sleep. The background pain is typically aggravated by activity and ultimately can start to interfere with routine activities of daily living and quality of life.

Management options include non-surgical and surgical treatments. Ideally, the non-surgical treatments should be exhausted before surgical treatments become necessary.

Non-Surgical Treatments

Physiotherapy Strengthening Classes

All of the evidence shows that one of the best ways to help your knee arthritis is Physiotherapy. It is important to attend a chartered physiotherapist for quadriceps strengthening and resistance exercises. These can make a huge difference to reducing the pain associated with osteoarthritis. Your local chartered physiotherapist is a vital part of your treatment. As strengthening is so important, we have set up Knee Arthritis Rehab Classes at the UPMC/WIT Arena in Waterford, Aut Even in Kilkenny and Castlebridge in Wexford.


Patients who understand their condition have been shown to manage their knee arthritis better. Please read all about it, as education helps. Useful websites include and

Activity Modification

There is no role for rest! Naturally one would think that if the problem is ‘wear and tear’ in the knee, then resting might slow down the progress of the arthritis – however the opposite is the case.  This means enjoying as many activities as your knee will allow, while obviously avoiding activities that aggravate your pain. Cycling, swimming and a cross trainer are comfortable ways to exercise without aggravating your knee pain. Try not to let your knee pain interfere with your daily activities and exercise routine.

Weight Loss

This is a vital part of managing your arthritis. The less weight your knee has to hold, the less symptomatic and painful your knee will be. Your knee takes six times your body weight when you ascend a step, so every extra kilogram is multiplied by six. Also, fat cells secrete chemicals that exaggerate your pain levels. So weight loss is really critical.


Your improvement will have “ups and downs” so use Rest, Ice, Compression and Elevation for acute flare-ups of your pain.


Heel wedges, knee sleeves and more rigid “off-loading” braces can help to re-align the knee and reduce pain levels. Simple neoprene knee sleeves are available in most chemists and well worth trying. Always opt for a looser rather than tighter sleeve, as tight sleeves cause discomfort.


This is an “over the counter” herbal type medication that has been shown to give some symptomatic relief and help slow the progression of osteoarthritis. Talk to your pharmacist regarding allergies and potential interactions with your current medications before you start.


You are always better to mask your pain and remain active, rather than limit activities because of pain. All painkillers, be they gels or tablets, should be taken on an “as needed” basis initially, increasing to “a regular basis”, as pain progresses. I suggest you start with an anti-inflammatory gel (as needed and then regularly). When tablets become necessary, Paracetamol should be tried first (as needed and then regularly), followed by an anti-inflammatory tablet. Both Paracetamol and the anti-inflammatory tablets can be taken together if necessary. If the pain persists despite Paracetamol and an anti-inflammatory, a morphine type painkiller may be necessary (either patches or tablets). Please ensure you consult with your GP – who will guide you up the steps of the analgesic ladder.


Injecting the knee with either Steroid or Hyaluronic Acid can be useful. The literature suggests that 60% of patients will note some improvement for a 12-month period. One rare potential complication of an injection is infection, so I prefer to inject joints in our minor ops theatre. Another complication is the unpredictable response to the injection – so people can great excellent sustained relief, however not everyone. Injections are performed with you wide awake, so you can drive down and drive home again yourself, with no restrictions on activities on the day of the injection.

Surgical Treatments

1. Knee Arthroscopy & Washout

This is “keyhole” surgery using a camera and shaver inserted into the knee to remove any loose fragments and tidy up inside the joint. The response to the arthroscopy is a little unpredictable, but can work well, providing more information regarding the degree of arthritis and offering a window of opportunity to make physiotherapy easier.

See video on knee arthroscopy

2. Partial Knee Replacement Surgery

“End-stage” knee arthritis is knee arthritis where bone is rubbing on bone (all the cartilage is gone). This is a very painful condition. If non-surgical treatment has failed, then surgical treatments might be considered.

Knee replacement should really have been called knee resurfacing, as essentially we resurface the two bones with new metal surfaces and place a strong plastic between the two metals, to avoid painful bone rubbing on bone.

We consider the knee to have three compartments: an inner (or medial) compartment, an outer (or lateral) compartment and a compartment between the kneecap (patella) and thigh bone (femur) called the patello-femoral compartment.

Knee arthritis most commonly affects all three compartments, and we call this tricompartmental (or global) knee arthritis. The surgical treatment for tricompartmental arthritis is a TOTAL Knee Replacement, where all three compartments of the knee are resurfaced. However, up to 40% of patients with ‘end-stage’ knee arthritis have arthritis in one of the three compartments, hence the development of PARTIAL Knee Replacement, resurfacing the affected compartment only and preserving the remaining two healthy compartments.

The most common compartment to develop isolated arthritis is the inner or medial compartment. This was first recognised in Oxford, UK and hence they designed the Oxford Partial Knee Replacement in 1976. The goal is to resurface the inner compartment only, to ease your pain and stop progression of the arthritis to the remaining two healthy compartments. Thus it is considered a definitive knee replacement option, as opposed to a temporary measure.

See video on partial knee replacement surgery

Complications of PARTIAL Knee Replacement Surgery

Please note that on rare occasions, I start a PARTIAL Knee Replacement, but if the arthritis was more advanced than expected, I may opt to immediately convert to a TOTAL Knee Replacement during the surgery.

  • Infection: 1% risk necessitating implant removal and antibiotics.
  • Clots: 1.3% of patients can develop a leg clot, which can travel to the lung (a pulmonary embolus) in 0.8% of patients.
  • Fracture: I ask that you use two crutches for six weeks after the surgery to reduce your fracture risk and allow the implants adequate time to bond to the bone.
  • Medical Complications: can arise in 3% of patients, so everyone is seen in the Pre-Assessment Unit and Joint School before their surgery.
  • Progression of your arthritis: there a low risk that the arthritis could spread to the two remaining compartments of your knee.
  • Stiffness: adhering to the physiotherapy programme is really important to avoid stiffness. Up to 5% may need a manipulation under anaesthesia at 6 weeks to help their movement.
  • Skin numbness: is present on the outer side of the incision in everyone.

3. Total Knee Replacement Surgery

Knee replacement surgery involves resurfacing the knee joint to eliminate the painful rubbing of “bone on bone”. Knee Replacement should really be called Knee Resurfacing Surgery.  The surgery is generally very successful, with 85% of patients satisfied with their outcome after one year. However the international literature shows that at least 15% of patients can be dissatisfied, so one must make the decision very carefully, as complications can arise. The key to a successful outcome following knee replacement is good pre-operative education and setting clear and reasonable expectations for the surgery. It often takes 1 year to fully recover after a knee replacement operation.

When you have a knee replacement operation, your native, painful knee is replaced with metal on plastic – so it will never work “like a new knee”  The expectations following the surgery must therefore be realistic. The primary goal of the surgery is to avoid complications and to ease your knee pain. Secondary goals are to return you to an acceptable functional level, such as long walks, doubles tennis etc.

Knee Replacement can be a Total Knee Replacement (60% of patients) or a Partial Knee Replacement (40% of patients). The decision to proceed with either a Total or Partial Knee is based on many factors, which we can discuss on the day. In a Toal Knee Replacement, all three compartments of the knee are resurfaced, however in a Partial Knee Replacement, only the affected area is resurfaced.

See video on knee replacement surgery

Complications of Total Knee Replacement

Knee replacement surgery has a complication rate of up to 6%, with major complications occurring in 2% of patients. Infection can occur in up to 1% of patients, which would necessitate antibiotics and possibly further surgery. Clots can develop in the leg in 1.3% of patients and can travel to the lung in 0.8% of patients (a pulmonary embolus). We will give you Aspirin for 4 weeks after the surgery. We will also get you moving your legs and walking as soon as possible to reduce this risk. Other significant medical complications can arise in 1% of patients, with more minor medical issues (e.g. urinary tract infections, delayed wound healing) in 2% of patients. Large studies suggest that up to 2% of patients can have unexplained knee discomfort (“Medically Unexplained Symptoms”) despite the wound and x-rays looking normal. Approximately 5% of patients may need a manipulation of the knee under anaesthetic – to improve their post-operative range of motion. The best predictor of post-operative range of motion, is the pre-operative range of motion. Up to 70% of patients will report a ‘knocking sensation’ within the knee – which is the metal on plastic sound and absolutely nothing to worry about.  All patients have a small area of skin numbness on the outer side of the wound.

Please note that obesity and inflammatory arthritis (Rheumatoid Arthritis or Psoriatic Arthritis) increase the risk of developing complications, in particular the infection risk is significantly increased. Weight loss is an essential part of treating knee osteoarthritis.

I tell patients that it can take 3 months to get over their operation, but that they should find gradual improvements as each week progresses.

Partial Knee Replacement AP View
Partial Knee Replacement Lateral View
Total Knee Replacement

Surgery – What to expect?

Before Surgery

Joint School and the Pre-Assessment Unit

This is a free educational programme run by UPMC, to address all of your questions and concerns, run by Jo Breheny on (051) 319845. Jo will spend time with you and a relative, to discuss what to expect before, during and after your surgery. She will help set realistic expectations in terms of recovery. The more you understand about the surgery, the easier you will find the journey to recovery.

Physiotherapy pre-habilitation

Please attend a Chartered Physiotherapist to start quadriceps strengthening exercises and re-attend this physiotherapist after your surgery to continue your rehab programme. You will have a better outcome under the guidance of a Chartered Physiotherapist.


Prior to admission to hospital, I recommend you shower twice a day for three days, gently cleaning your skin with normal soaps.

Hospital Stay

 Typically you will be admitted to the hospital on the morning of your operation. Before theatre you will be fasting, so we will give you a sugar drink and start your painkillers (pre-emptive pain relief). In theatre, I will answer any further questions. Don’t worry, you will not hear the operation! That evening or the next morning we get you out of bed to start walking with crutches. Please bring loose clothes and appropriate safe footwear.

Upon Discharge

You can be discharged once you are safe on your crutches and your pain is under control. You will be given a prescription for pain killers and Aspirin for four weeks to keep your blood thin and reduce the risk of a blood clot.

If you’ve a had a partial knee replacement, you can more than likely go home the day after surgery. If you’ve had a total knee replacement, you can go home on day 2 or 3 after surgery.

Our physiotherapy team will chat with you about your physiotherapy arrangements, as post-operative physiotherapy is a vital part of your recovery.

After partial knee replacement surgery, I ask that you use your crutches for six weeks and I see you again at the six-week stage in the Rehabilitation Suite for a new x-ray and physiotherapy review. After total knee replacement, you can weight-bear as tolerated through your knee and you can drop your crutches once comfortable. Your physiotherapist will guide you in this regard.

Everyone is sore after the surgery, so I always suggest you ‘over-do’ rather than ‘under-do’ the painkillers and use rest, ice and Physicool wraps while recovering.

Pain relief after knee replacement surgery can be gradual, variable and incomplete. Some patients report ongoing discomfort for up to two years. Occasionally anti-inflammatory pain killers are necessary. Skin numbness and hesitancy about kneeling can persist, but I encourage you to use, enjoy and push your new knee, as much as you feel able. Jo Breheny is always available to offer advice if you have any concerns.

Need More Information?

See Videos

Other knee Treatments

Meniscal Tears

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Patellofemoral Pain

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