A Comprehensive Guide to Knee Replacement Surgery

Knee replacement surgery is usually performed when the surface of the knee joint is worn. This leads to pain, structural deformity and loss of function. The procedure involves the replacement of either part or all of the surfaces of the knee with an implant. The procedure restores mobility and function to the joint, and reduces or eliminates pain.

Total knee replacement surgery typically takes between 30 and 90 minutes, most often under general anaesthetic. Patients usually remain in hospital for 2 to 3 days (or 1 to 2 days for a partial knee replacement).

The different anaesthetic (and sedation) options include: general anaesthetic, regional anaesthetic, spinal block and epidural. Lighter sedation can be achieved using a combination of some of these approaches, and will depend on clinical need and patient preference.

Patients should expect to be walking - relatively pain free - within a few hours of their surgery to expedite the early stages of recovery.

Getting the diagnosis right

At the initial consultation, your consultant knee surgeon will confirm the diagnosis. They will take a detailed medical history, perform a careful clinical examination and review radiological imaging (usually X-ray) to confirm the exact level of degeneration in the joint. Very occasionally, further imaging may be necessary in the form of a CT, MRI or Bone Scan. Once the diagnosis is confirmed, a treatment plan can be discussed and agreed with you.

Questions to ask your knee surgeon

There are various types of knee replacement surgery with many subtleties to the exact procedure and the care you receive. The below will help inform discussions with your surgeon and ultimately help you when selecting both a hospital and surgeon.

Total Knee Replacement (TKR)

TKR is the most common procedure for the treatment of an osteoarthritic knee where all three compartments of your knee joint are resurfaced. Most patients will have some degree of degeneration in more than just one compartment of their knee joint, so just replacing one of the three compartments may not render the knee pain-free, and may require a revision procedure at a later date.

An experienced surgeon with a proven track record, nurses and physiotherapists specialising in orthopaedics, and high-quality facilities should be able to deliver a rapid and successful recovery, improving pain and function permanently. With modern technology, knee replacements appear to be lasting 20 to 30 years, so success rates are very high. Note: do ask your surgeon for their volume and performance record - recorded on the National Joint Registry.

When can a partial knee replacement be considered?

An alternative to a total joint replacement is a partial (otherwise known as a unicompartmental or unicondylar) replacement. The partial replacement only replaces one of the three compartments of your knee joint with a metal and plastic implant. When successful in an appropriate case, this technique may result in a quicker recovery and less pain for patients.

However, this procedure does have a much higher revision rate as seen on the UK's National Joint Registry, and you may need further revision surgery if the rest of your knee wears out or becomes painful. Careful patient selection with a trusted surgeon is the key to obtaining a good result.

Is robotic assisted surgery an advance?

(Eg. eg. Mako SmartRobotics, NAVIO Surgical System and ROSA®). These are robotic arm assisted systems used to custom align your implant and help with the soft tissue balancing of the knee, allowing for accurate implantation.

More surgeons are becoming proficient with innovations such as these, and results are promising. However we do recommend patients select a surgeon with a significant track record in robotic assisted surgery.

A discussion with your surgeon about whether the use of this technology is appropriate is also important as it can take longer than conventional surgery, which may have its disadvantages.

Note: these navigation systems may require additional imaging such as CT scans which can add to the overall procedure cost.

A few words about custom made knee replacement

This is where a customised implant can be made for your knee, based on pre-operative CT scans. Whilst this technology has been available for over a decade, there is still little evidence that this leads to better recovery or long term survival (of the joint). Customised implants are also significantly more expensive.

Moreover, conventional modular implants in a standard knee replacement can allow for many more options of “custom fitting and soft tissue balancing of the knee”.

Note: when recommended a custom knee replacement for your knee, do explore the rationale carefully with your surgeon.

Rapid Recovery Programmes

This is when your pre operative, in-hospital and post operative care is optimised by your surgeon and hospital to shorten your recovery (through advancing anaesthetic, surgical and rehabilitation techniques). Rapid Recovery Programmes are usually found in hospitals performing high volumes of orthopaedic surgeries with dedicated orthopaedic units.

Note: at your initial consultation, do ask your surgeon about this programme at your selected hospital.

How quickly do patients recover from knee replacement surgery?

There is much variation in timeframes when it comes to recovery. Returning to full strength is dependent on many factors including fitness, age, surgical approach, the extent of damage/disease, and adherence to physical therapy.

Patients should expect to be walking in a few hours (as part of a rapid recovery programme); able to go up and down stairs within three days; driving within 2 to 6 weeks, and a return to light sports within 6 to 8 weeks. This is clearly highly dependent on the individual but ultimately patients should be prepared for a gradual recovery - supported by a progressive exercise programme - with complete recovery taking up to a year.

What are the potential complications of knee replacement surgery?

Possible complications to be aware of following knee replacement surgery include: infection, urinary retention, local swelling and stiffness, and venous thromboembolism (Deep Vein Thrombosis or pulmonary embolus). The best hospitals have organised care arrangements to deal with the more regular post-operative issues.

Note: you should discuss complication rates with your surgeon and have a clear understanding of how your hospital is set up to cope with these in the unlikely event that they arise.

Choosing a hospital and surgeon for you

Volumes and specialisation: surgeon data

Generally, it is reasonable to expect that a fellowship-trained specialist consultant knee surgeon who undertakes a significant volume of procedures each year is likely to give you a good outcome from your surgery.

Surgeons undertaking total knee replacement surgery in the UK perform an average of 50 implants per year (see the National Joint Registry or NJR), with some surgeons performing far greater numbers. Please note: the NJR's latest annual data spans the first year of Covid 19 - ending 31 March 2021, so figures for the year are lower than normal.

In general the higher the volume of knee replacements a surgeon performs each year, the greater their expertise will be - which correlates with better outcomes. So you should aim to choose a higher than average volume knee replacement surgeon with low revision rates, recorded on the National Joint Registry. Please ask your surgeon for their up-to-date revision (re-do) rates as evidenced in their own annual NJR summary.

Specialist hospital facilities

From a hospital perspective, a dedicated orthopaedic ward (with only screened elective orthopaedic patients), senior resident doctors, dedicated specialist nurses and physiotherapists, and a dedicated pain control team are desirable to carefully manage your post-operative care and pain and identify potential complications early.

Your pain medication should be tailored to optimise early mobilisation of your knee alongside a rapid recovery programme that ensures a quick return to normality. One of the most common complications after surgery is urine retention after your anaesthetic. Specialist orthopaedic units often have robust urology protocols involving bladder scanning and catheterisation policies to deal with common issues with postoperative urinary retention. Similarly, dedicated units will also have robust venous thromboembolism prevention protocols and policies.

Patient experience and feedback

Hospitals collect two main types of information from patients: direct reviews and outcome scores. Outcome scores - Patient Reported Outcome Measures (PROMS) - capture the effectiveness of treatment patients received over the longer term, as opposed to their experience in hospital. Hospitals often collect this data before and at a 6 month interval after surgery.

At Compare my Care, we look carefully at all available information so we are able to help you select the best hospital and surgeon for your procedure.

How Compare my Care works for you

Compare my Care analyses both surgeon and hospital performance data, each hospital's facilities and the available patient experience information to help patients compare providers so they can choose appropriately.

Our medical specialist concierge team will work with you to arrange an initial consultation with an experienced, specialist knee surgeon with a high level of relevant expertise at your selected hospital.

Note: Compare my Care does everything possible to secure a fixed price for each procedure, but a patient's specific medical needs may result in diagnostic and treatment variation which can impact costs.

Introducing Protect my Care

‘Protect my Care’ is a unique ‘cash-back' insurance policy provided by Compare my Care. It was created to give patients additional protection and peace of mind when paying for their own surgery - and comes at no extra cost to the patient.

All surgeries come with risks but in the hands of a super-specialist surgeon these can be reduced further. However, in the rare event that a repeat surgery is needed within 12 months, patients will be refunded the cost of their original procedure - to spend as they see fit.