General Surgical Risks — What They Really Mean

Part of The Joint Replacement Guide — Phase 3: Understanding the Risks · Article 12 of 42 · Hip & Knee

Key Points

  • All surgery carries some risk, and understanding it in plain terms helps you make an informed decision.
  • Bleeding, infection, blood clots, and anaesthetic complications are the general risk categories relevant to almost any major operation.
  • Modern surgical and anaesthetic practice has meaningfully reduced these risks compared with even a decade or two ago.
  • Serious complications are uncommon, but knowing the warning signs matters — covered in detail in a later article on red flags after surgery.

Bleeding

Some blood loss is expected with any joint replacement, but modern techniques — including the routine use of a medication called tranexamic acid, which reduces bleeding during and after surgery — have significantly lowered the need for blood transfusion compared with a generation ago. Significant bleeding requiring transfusion is uncommon, and the need to return to theatre specifically to control bleeding is rare.

Infection

It’s important to distinguish between a superficial wound infection, which affects the skin and is usually treated successfully with antibiotics, and a deep or periprosthetic joint infection (PJI), where infection involves the implant itself. PJI is far less common but more serious, sometimes requiring further surgery to treat. National registry data puts the risk of PJI after primary hip or knee replacement at approximately 1 in 100, though your individual risk is influenced by factors such as weight, diabetes control, and smoking, which is why these are addressed as part of pre-operative optimisation. Prevention measures used routinely include antibiotics given at the start of surgery, strict sterile theatre technique, and careful skin preparation.

Blood Clots (VTE)

Venous thromboembolism (VTE) refers to blood clots forming in the veins, usually in the leg (deep vein thrombosis, or DVT), which can occasionally travel to the lungs (pulmonary embolism, or PE) — the more serious of the two. Reduced mobility after surgery increases this risk, which is why early mobilisation — being helped to stand and walk on the same day as your operation in most cases — is such a central part of modern joint replacement care. Additional prevention includes mechanical measures such as compression stockings or pumps, and often a course of blood-thinning medication for a defined period after surgery, following national guidance.

Anaesthetic Complications

Anaesthesia carries its own set of risks, ranging from common and minor (nausea, sore throat after a general anaesthetic) to rare and more serious. These are covered in more detail in the next article, and your anaesthetist will discuss the specific risks relevant to you individually as part of your pre-operative assessment.

Other General Risks

Injury to a nearby nerve or blood vessel is rare but possible, and is covered specifically for hip and knee replacement in the next two articles. Patients with existing heart or lung conditions carry a somewhat higher risk of cardiac or respiratory complications around the time of surgery, which is why these conditions are carefully assessed and managed beforehand. Overall mortality risk associated with elective hip or knee replacement is very low — well under 1% — but it is not zero, and it is right that this is mentioned honestly as part of informed consent, even though for the overwhelming majority of patients the operation is straightforward and safe.

In More Depth

Complication rates for joint replacement have continued to fall over recent years, reflecting improvements across the whole pathway — better pre-operative optimisation, Enhanced Recovery After Surgery (ERAS) protocols, refined surgical technique, and more consistent use of evidence-based VTE and infection prevention measures. National joint registry data allows these trends, and individual surgeon and unit outcomes, to be tracked over time, which is covered in more detail later in this guide when we discuss how to read a surgeon’s NJR profile. It’s worth remembering that published risk figures are population averages — your own individual risk will be somewhat higher or lower depending on your specific health factors, which your surgical and anaesthetic team will discuss with you directly.

This article is general information and does not replace individual clinical advice. Your surgical and anaesthetic team will discuss your individual risk profile with you before surgery.

Sources

  • National Joint Registry — Annual Report
  • NICE guideline NG89 — Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism
  • GIRFT (Getting It Right First Time) — National Report on Orthopaedics
  • British Orthopaedic Association — infection prevention guidance

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