Obesity
- BMI of 40 or more raises infection, wound complications, dislocation and revision after arthroplasty
- Many units set BMI thresholds for elective joint replacement
- Optimise through weight loss programs, dietitian review and bariatric referral where appropriate
- Exposure and positioning are harder, lengthening operative time
Smoking
- Impairs wound healing and raises infection risk
- Increases nonunion after fracture and spinal fusion
- Stopping 6 to 8 weeks before surgery halved complications (Møller, Lancet 2002)
- Nicotine replacement is safe around surgery
- Quitline (13 78 48) and GP support improve success
Alcohol and Substance Use
- Screen with the AUDIT tool
- Risk of withdrawal and delirium, give thiamine
- Opioid tolerant patients need a planned analgesic regimen
- More than 3 standard drinks a day raises postoperative complications
- Injecting drug use raises the risk of infection
Malnutrition
- Albumin under 35 g/L and low lymphocyte count raise infection risk
- Screen with the MUST or MNA tool
- Vitamin D deficiency is common in fracture patients
- Nutritional supplements after hip fracture surgery improve recovery
Diabetes
- See Diabetes & Hip replacement
- HbA1c above 8% (64 mmol/mol) is a common threshold to defer elective arthroplasty
- Perioperative hyperglycaemia raises infection risk even without known diabetes
Other Factors
- Investigate and treat anaemia before elective surgery, often with iron
- Treat dental and skin infections before arthroplasty
- Review immunosuppression, see Perioperative Management of Rheumatological Medications
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.