Am I Fit for Surgery? Pre-operative Optimisation

Part of The Joint Replacement Guide — Phase 2: Considering Surgery · Article 10 of 44 · Hip & Knee

Key Points

  • Preparing for surgery involves looking at your health as a whole. Many health risks can be reduced or managed before an operation.
  • Important areas may include diabetes control, smoking, anaemia, nutrition, physical fitness and weight—but what matters most differs from person to person.
  • Preparation is intended to make surgery and recovery safer. It should not be used simply to create barriers to treatment.
  • Body mass index (BMI), smoking or another health condition should not, by itself, prevent someone from being referred for consideration of joint replacement.[1]
  • Your hospital team will agree an individual plan with you. Your GP or another specialist may also be involved.

Why Preparation Matters

Every operation carries risks. These include infection, problems with wound healing, blood clots, and heart or breathing complications. Existing health conditions can also affect recovery.

Preoperative assessment allows the team to identify risks that may be reduced or managed before surgery. This preparation is sometimes called preoperative optimisation. It may take place alongside exercises and other “prehabilitation” intended to improve strength, mobility and confidence before the operation.[2,3]

Optimisation cannot remove every risk or guarantee a particular result. Occasionally, an operation may need to be postponed if proceeding at that time would carry a significant and avoidable risk. If this is suggested, the team should explain the reason, what support is available and how the decision will be reviewed.

Weight and Nutrition

Higher body weight is associated with an increased risk of some complications after joint replacement, including wound problems and infection. BMI is only one measure, however, and it does not provide a complete picture of an individual’s health or likely benefit from surgery.

NICE advises that people should not be excluded from referral for joint replacement because they are overweight or living with obesity.[1] Hospitals may use local pathways to support weight management and assess surgical risk, but decisions should be individualised and made through discussion with the patient.

If weight loss would be helpful and achievable, the team should offer practical support rather than simply set a target. Crash dieting before surgery is not advisable, as adequate protein, vitamins and energy are needed for healing. People who have lost weight unintentionally, have a poor appetite or may be undernourished should tell the pre-assessment team. A dietitian may be able to help.

Diabetes and Blood-Sugar Control

Diabetes can increase the risk of infection and other complications around surgery, particularly when blood-sugar levels are persistently high. The team will usually review recent blood tests, including HbA1c, and agree how diabetes medicines should be managed before, during and after the operation.[4]

Hospitals may use different HbA1c targets or pathways. A result outside a local target does not, by itself, describe the whole risk or determine whether surgery is appropriate. Where improvement is possible, your GP, diabetes team and hospital team should help you achieve this safely.

Do not stop or alter diabetes medication yourself. Some medicines require specific arrangements around surgery, and the clinical team will tell you what to do.

Smoking

Smoking increases the risk of breathing problems, wound complications and delayed healing. Stopping before surgery can reduce these risks, and stopping earlier generally provides more benefit.[5]

Even if the operation is approaching, it is still worth asking for help. NHS stop-smoking services can provide behavioural support and treatments such as nicotine replacement. If stopping completely feels difficult, discuss this honestly with the team so that appropriate support can be arranged.

Smoking should not, by itself, prevent referral for consideration of joint replacement.[1]

Anaemia

Anaemia means that the blood has a reduced capacity to carry oxygen. It may increase the likelihood of complications or the need for a blood transfusion during major surgery.

A blood test is usually performed before joint replacement. If anaemia is found, the clinical team should investigate its cause rather than assume that it is due to iron deficiency. Treatment may involve iron, vitamin B12, folate or management of another underlying condition. Identifying and treating anaemia as early as possible is an important part of perioperative care.[6]

Do not begin high-dose iron supplements unless advised to do so, as not all anaemia is caused by iron deficiency.

Dental Health

Good everyday dental care is sensible, and you should tell the surgical team if you have toothache, facial or gum swelling, a dental abscess, or dental treatment planned around the time of surgery. An active dental infection may need assessment and treatment before an elective joint replacement.

However, evidence does not show that mandatory dental screening or “dental clearance” for every patient reduces the risk of infection in a new hip or knee replacement.[7] Whether a dental review or a delay between dental treatment and surgery is appropriate should therefore be decided individually, taking account of your symptoms, the treatment required and the hospital’s pathway.

Other Health and Medication Checks

Pre-assessment may also include:

  • checking your blood pressure, heart and lung health;
  • reviewing kidney problems, sleep apnoea or previous blood clots;
  • assessing frailty, mobility and the support available at home;
  • checking for current infections or skin problems;
  • reviewing all prescribed medicines, over-the-counter treatments and supplements; and
  • discussing previous problems with surgery, anaesthesia or blood transfusion.

Bring an up-to-date medication list to your appointment. Do not stop anticoagulants, diabetes treatments or any other prescribed medicine unless your clinical team tells you to do so.

Contact the hospital if you develop a significant new illness, infection, skin wound or dental problem shortly before surgery. The team can then decide whether any change to the plan is necessary.

Who Is Involved?

The pre-assessment team coordinates much of this work and may include nurses, anaesthetists, pharmacists and other specialists. Depending on your needs, your GP, diabetes team, smoking-cessation service, dietitian or anaemia service may also contribute.

The aim is to identify what matters for you, explain the benefits and risks clearly, and agree achievable steps that improve safety without creating unnecessary delay.

This article provides general information and does not replace advice from your own clinical team. Individual recommendations and hospital pathways vary. Seek advice before changing medicines, supplements, diet or activity in preparation for surgery.

References

  1. National Institute for Health and Care Excellence. Osteoarthritis in over 16s: diagnosis and management. NICE guideline NG226. London: NICE; 2022. Recommendations 1.6.1–1.6.4. Available from: https://www.nice.org.uk/guidance/ng226/chapter/Recommendations
  2. National Institute for Health and Care Excellence. Joint replacement (primary): hip, knee and shoulder. NICE guideline NG157. London: NICE; 2020. Available from: https://www.nice.org.uk/guidance/ng157/chapter/Recommendations
  3. Royal College of Anaesthetists. Preparing for surgery: Fitter Better Sooner. London: RCoA. Available from: https://www.rcoa.ac.uk/documents/fitter-better-sooner/introduction
  4. Centre for Perioperative Care, Diabetes UK. Guideline for perioperative care for people with diabetes mellitus undergoing elective and emergency surgery. London: CPOC. Available from: https://www.cpoc.org.uk/guidelines-and-resources/guidelines/guideline-diabetes
  5. Royal College of Anaesthetists. Preparing for surgery: smoking. In: Fitter Better Sooner. London: RCoA. Available from: https://www.rcoa.ac.uk/documents/fitter-better-sooner/introduction
  6. Centre for Perioperative Care. Guideline for the management of anaemia in the perioperative pathway. Updated 2025. London: CPOC; 2025. Available from: https://www.cpoc.org.uk/guidelines-and-resources/guidelines/anaemia-perioperative-pathway
  7. American Academy of Orthopaedic Surgeons, American Association of Hip and Knee Surgeons. Prevention of total hip and knee arthroplasty periprosthetic joint infection in patients undergoing dental procedures: evidence-based clinical practice guideline. Rosemont, IL: AAOS; 2024. Available from: https://www.aaos.org/globalassets/quality-and-practice-resources/dental/dental-2024/prevention-of-total-hip-and-knee-arthroplasty-pji-in-patients-undergoing-dental-procedures-cpg.pdf

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