FAQ

Having decided to go ahead with surgery, you will be referred to Joint School. At this session you will meet members of the multidisciplinary team including therapists and pain team nurses who will talk to you about the procedure and what to expect before, during and after surgery.

You will also be given a date to attend the pre-operative assessment clinic. At the pre-operative assessment, the team have the opportunity to make sure you are medically fit for the anaesthetic and the operation.

They will review your medications, so please bring these with you. If you are taking blood thinning medications (such as aspirin, clopidogrel or warfarin) they will need to be stopped a few days before your surgery and you will be given special instructions regarding this.

In the clinic your blood pressure will be checked, you will have blood tests, have swabs taken to look for MRSA and it may be necessary to listen to your chest and do a tracing of your heart (ECG).

Once cleared by the pre-operative assessment team we will be able to proceed with your surgery.

Self Isolation to protect from COVID-19

In order to protect yourself, and all patients and staff within the hospital it is vital that everyone within the hospital environment is COVID negative. Pre-operative patients will therefore need to self-isolate for 14 days before their surgical date and you will be screened to confirm that you do not have any symptoms of coronavirus (flu-like symptoms, cough, fever, sore throat, muscle aches, loss of sense of taste and smell). You will also have throat and nose swabs sent to confirm that you are Coronavirus antigen negative. For more information on self-isolation see FAQ Self-Isolation- what does it mean?

Day Before

To reduce the risk of infection all patients should have a shower or bath at home before surgery. Patients are advised to remove hair from the surgical site and not to apply moisturisers/oils/creams/lotions 48 hours prior to surgery.

• Do not drink any alcohol from the day before the surgery
• Do not smoke or vape for at least 24 hours before your admission
• Do not take recreational drugs for 48 hours before your admission
• Do not wear any make-up or nail varnish. False nails should be removed
• Remove piercings and jewellery – except for a wedding ring

What you should bring to hospital

Please bring with you

• All tablets, medicines or inhalers that you have been prescribed (including those you stopped prior to surgery). Please ensure that all medication is in the original packaging and labelled with your name
• Personal items - Night clothes, Dressing gown, slippers
• Comfortable day clothes
• Your spectacles
• Denture pot (as you will be asked to remove any false teeth)
• Toiletry items – toothbrush, toothpaste, flannel, soap, shampoo, shaving utensils, comb/hairbrush
• Mobile phone and charger

You might also want to bring

• Tissues and baby wipes
• Your hearing aid
• Sanitary products
• Mobility aids such as a frame or crutches
• Items of religious importance to you
• Books, magazines
• Writing paper and pen
• Non perishable snacks

On the day of surgery

All patients need to fast for 6 hours before any anaesthesia or sedation is administered. Therefore, no solid food, milk, fizzy drinks, fruit juice or milky tea/coffee are allowed. You may drink clear fluids like water, black coffee or black tea up to 2 hours before the operation.

Please follow the advice of the Hospital Pharmacist, Anaesthetist or Pre-op Assessment Nurse regarding taking or stopping your routine medication before the operation. Please bring all your medicines with you to the hospital.

If you are using any devices (eg. CPAP machine), please bring it with you as you may need it whilst in the hospital.

If you are having a spinal anaesthetic you can listen to your own music therefore, you may wish to bring your own MP3 device and earphones.

Prior to surgery a nurse will take you to your room where health checks and a nursing assessment will be completed. You will be given a gown, underwear and stockings to change into, however, you will remain in your own clothes until the theatre team are nearly ready to collect you.

I will see you with my anaesthetist in your room where we will discuss your surgery and consent you for the procedure and draw an arrow on your skin on the side of the surgery (using a thick black marker pen).

Once all the checks have been done and it is your turn for surgery, you will be escorted to the operating theatre.

During surgery you will either be asleep (with a general anaesthetic) or remain awake but be completely numb from the hips down (with a spinal anaesthetic). It is important to point out that with a spinal anaesthetic you can also have sedation which means that you will be sleepy and therefore not experience the noises during the surgery.

It is preferable for patients in the most part to have a spinal anaesthetic for their lower limb procedures (excluding knee arthroscopy).

Advantages of Spinal Anaesthesia

• Excellent pain relief during and for a few hours after the operation
• Reduced need for stronger painkillers such as morphine
• Least effect on lungs and breathing
• Less sickness (nausea and vomiting) compared to a general anaesthetic
• Ability to eat and drink soon after the operation
• Greater mobility during first post-operative day
• Less risk of developing blood clots (DVT) compared to general anaesthetic

For more information click here

In some situations, such as revision surgery, previous spinal surgery, failure of the spinal anaesthetic or patient preference a general anaesthetic will be required.

For more information about anaesthetic choices for hip and knee surgery click here

I do not recommend the Direct Anterior Approach (DAA) to perform a hip replacement. These are my reasons for not adopting this surgical approach

• Poor visualisation of the acetabular socket leading to an increased risk of malpositioning of the acetabular component
• Often require sacrifice of piriformis tendon which when cut cannot be repaired
• Higher risk of complications especially fracture to the femur and infection
• No difference in post-operative function beyond 6 weeks

I learnt the direct anterior approach during my Fellowship training in Canada where I performed around 50 hip replacements via this approach. I am very grateful for having had the experience in this technique and feel that I can therefore give a balanced opinion regarding its advantages and disadvantages.

The DAA is marketed as a muscle sparing approach and while on paper this is true my experience was that in at least half of the operations the piriformis tendon was sacrificed to allow instrumentation of the femur. In this situation it is certainly not muscle sparing as this tendon once cut via the DAA cannot be repaired and one of the key external rotators of the hip is lost.

It is not possible to visualise some of the key anatomical structures in the hip when the DAA is performed. In particular visualisation of the socket. The transverse acetabular ligament is a key landmark structure that is used to orientate the implanted cup into the correct degree of anteversion. It is not possible to see this landmark via the DAA, to compensate for this deficiency an intra-operative X-ray is taken to check for the position. The problem with using an X-ray to determine the cup position is that the X-ray beam can be orientated into any position which will in turn make the cup appear to be in the correct position. Short term risks of cup malpositioning can result in dislocation and long-term risks will lead to increase wear characteristics and loosening which, in turn, will result in early failure of the hip replacement.

The femur needs to be presented through the incision so that it can be instrumented and the correct implants inserted. This is why piriformis tendon often requires sacrificing. Sometimes, in an effort to protect piriformis tendon there can be a lot of force levering on the femur to allow the instruments to be inserted down the medullary canal. If this force is too great, particularly in patients with weaker bone, the bone can give out and a fracture can occur. If this is a small crack it can be wired during the operation, larger cracks that propagate down the femur cannot be fixed via this approach as it is nonextensile meaning that a second incision on the side of the leg will need to be performed. In training, I was always taught to use approaches that can be extended if necessary.

As with any new technique there is an initial rush to take up the skill and it is easily marketable in a competitive environment. It can take time for the evidence to catch up. There is now increasing evidence to show that there is an increase in complications following a DAA. For example, in a recent paper from the US¹, a 5 year study of consecutive hip replacements equating to 3,500 THRs were assessed, they found a higher incidence of complications in the DAA group when compared to all other approaches. In particular there was a higher risk of superficial and deep infection, implant loosening, revision surgery and dislocation.

One advantage of the DAA is that patients do rehabilitate quicker. However, this improvement in functional outcome is only present up to the first 6 weeks after surgery. Beyond the 6 week post-operative mark there is no difference in functional outcome between a DAA or a Posterior Approach². In my opinion, the early benefit of the DAA in comparison to a posterior approach should be viewed cautiously. A hip replacement is an operation that should last in excess of 20 years and therefore an improvement in the first 6 weeks is of little relevance when compared to the whole lifespan of the implant, especially when the extra risks and uncertainty over the long-term implant survival are considered.

It is for the reasons I have outlined above that I have not continued to adopt the Direct Anterior Approach and feel that a Posterior Approach to the hip provides the most reliable, reproducible and safest surgery through which to perform a total hip replacement.

1. Surgical approach significantly affects the complication rates associated with total hip arthroplasty. Bone and Joint Journal. 2019, 101-B: 646-651
2. The direct anterior approach in total hip arthroplasty a systematic review of the literature. Bone and Joint Journal. 2017; 99-B: 732–40

Many patients are fearful of a hip dislocation and rightly so, it is however a rare occurrence especially now with modern hip replacement techniques.

The highest incidence of hip dislocation after joint replacement occurs within the first 6 weeks after surgery. This is whilst the healing process and scar tissue is forming around the operated hip joint. The weakest part of the hip is through the entry point where the operation has been performed ie with a posterior approach it is the back of the hip.

The most at-risk position is during deep hip flexion. That is why I inform patients that for the first 6 weeks they should refrain from sitting in a position where their knee is above the level of their hip as this will equate to flexion of the hip joint above 90 degrees. After 6 weeks further movement is allowed as the hip capsule has healed enough to provide a strong restraint to extra movement and it is safe to do so.

Sometimes patients are told that they will have to lie on their back during the night and should not cross their legs but I do not believe this level of restraint is necessary.

Driving

It will be safe to return to driving 4-6 weeks after a total hip replacement. It is important to liaise with your car insurer to confirm that they will insure you during the early recovery stage. If you have an automatic car and surgery is on the left leg you may be able to return to driving slightly sooner.

During the Corona Virus pandemic there will be an increase in the number of consultations being conducted by either telephone or video-link. I have listed a few helpful tips in order for you to maximise the benefit from these consultations.

Before your appointment

• Check your IT software
• Choose a suitable, quiet and confidential place for the consultation to occur
• Make sure you can login to the software
• Make sure your video is functioning
• View any previous imaging
• inform my secretary of any previous scans you may have had; it is very useful for me to be able to look at previous imaging.
• My secretary can get these scans linked across; she needs to know:
• Where the scans were performed
• When the scans were done

During your appointment

I will take a history of your symptoms and then perform an examination.

During the history it is helpful if you:

• Have your list of medications
• Have previous clinic letters available

During the examination

• Wear appropriate clothing – shorts to visualise your knee
• Mark out a particular area of pain with a pen - to make it clear where your pain is
• Have a family member or friend with you - to help with holding the camera during the examination.

Write down any questions you may have before the consultation or during the consultation as it is easy for them to slip from your mind.

These steps will enable you to get the most out of your virtual consultation.

What is PRESSORELAX?

PRESSORELAX combines two things in one device: a cold pack and gentle pneumatic (air) compression around the knee. It is used to help manage pain and swelling in the weeks after knee surgery or a knee injury.

It is a supportive treatment. It is meant to be used alongside the pain relief you have been prescribed and the exercises your physiotherapist has given you, not instead of them.

How does it work?

Cooling the tissues around the knee narrows the small blood vessels and slows down the inflammation that follows surgery. This can reduce swelling and make the joint feel more comfortable. Gentle, intermittent compression is intended to help fluid drain away from the area.

The cold packs use a gel that stays soft when frozen, so they mould to the shape of the knee rather than sitting on it as a hard block. Once taken out of the freezer, they stay within the intended therapeutic range of about 0–5°C for around 30 minutes.

Because the temperature is more controlled than ice or a bag of frozen peas, the risk of a cold injury is lower — but it is not zero, so the precautions below still apply. The packs are reusable and can be refrozen.

What the evidence shows

It is important to be straightforward about this, so you can decide whether it is worth it for you.

Research into cold therapy after knee surgery has produced mixed results. Taken together, the studies suggest:

• Pain often improves a little in the first few weeks after surgery, although the difference is frequently small.
• Some patients need less strong pain medication during the first week.
• Findings on swelling are inconsistent — some trials show a benefit and others show none.

Many patients find it comfortable and helpful in the early weeks after surgery. It is fair to say the evidence supports modest short-term comfort rather than a faster overall recovery.

When might it be useful?

• After knee replacement — partial, total or revision
• After ligament surgery, including ACL reconstruction
• After other knee surgery where significant swelling is expected
• During rehabilitation, when swelling is making your exercises harder

Important safety information

Do not use it:

• While your leg is still numb from a nerve block or anaesthetic, or if you have reduced feeling in the leg for any other reason. If you cannot feel the cold properly, you will not notice a cold injury developing.
• Over a wound that has not healed, or that is open or leaking.
• If the leg is hot or red, or you think the wound may be infected.
• If you have poor circulation in your legs (peripheral arterial disease), Raynaud’s, an allergy to cold, or nerve damage in your legs or feet, for example from diabetes — unless you are told it is safe.
• If you are not able to take it off yourself, or tell someone that it feels uncomfortable.

Stop using it and seek urgent medical advice if:

• Your calf becomes newly swollen, painful, hot or red.
• You become short of breath or develop chest pain.
• The skin under the pack turns white, grey, blistered or numb.

The first two can be signs of a blood clot, which is a recognised risk after knee surgery. The third can be a sign of a cold injury. Both need to be assessed quickly.

Using it safely

• Follow the manufacturer’s instructions for how long each session should last and how long to wait between sessions.
• Check the skin underneath every few minutes during the first few sessions.
• Never use it while you are asleep.
• Stop if it becomes painful rather than simply cold.
• Keep doing your physiotherapy exercises. Cold therapy does not replace them.

Where to get it

PRESSORELAX is supplied in the UK by Sovereign Medical. At the time of writing it costs £257, which includes one Freezsnow cold pack, the pneumatic knee unit and a ligament knee brace.

www.sovereignmedical.co.uk

Patients can get a 10% discount with the code SNOW10

[Declaration of interest: I can confirm that no financial or commercial relationship with the supplier or manufacturer exists.]

Arthrosamid is a permanent, non biodegradable injectable hydrogel made of 2.5% cross-linked polyacrylamide and 97.5% water. It is injected into the knee where it integrates with the synovial tissue lining the joint. The manufacturer reports that this cushions the joint and improves the elasticity of the tissue, reducing pain and improving function.

Does it work?

In studies published so far, Arthrosamid appears to be safe. My frustration is with the quality of the evidence that it works. Although the gel has been injected into knees for over 15 years and Arthrosamid has been sold for this purpose since 2021, there is still no published randomised controlled trial comparing it with a placebo or steroid injection. This would be the best investigation to prove whether it works.

The one randomised trial that exists compared it with hyaluronic acid, an injection that itself performs little better than placebo in osteoarthritis1 and it found the two to be similar2. Most of the remaining evidence comes from studies with no comparison group, where the placebo effect cannot be separated from any real benefit.

As a surgeon, I practise evidence-based medicine, and I do not think the current evidence is strong enough to recommend Arthrosamid. Given that it costs around £3000 and is permanent within the joint, I would not advocate its use.

1. Pereira TV, Jüni P, Saadat P, Xing D, Yao L, Bobos P, Agarwal A, Hincapié CA, da Costa BR. Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis. BMJ 2022;378:e069722. doi:10.1136/bmj-2022-069722
2. Bliddal H, Beier J, Hartkopp A, Conaghan PG, Henriksen M. Polyacrylamide gel versus hyaluronic acid for the treatment of knee osteoarthritis: a randomised controlled study. Clin Exp Rheumatol 2024;42:1729-1735.