Hip replacement surgery is performed to relieve persistent pain and improve mobility when a damaged hip joint is no longer responding adequately to non-surgical treatment. Most patients recover without a major complication, but like any major operation, hip replacement carries certain risks.
Understanding these risks does not mean expecting them to happen. It helps you distinguish between normal recovery symptoms and problems that may require medical attention. If you are considering hip replacement surgery, knowing the potential complications can also help you have a more informed discussion with your surgical team.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Are complications common after hip replacement?
Hip replacement is generally considered a safe and effective operation, and serious complications are uncommon. However, the risk is not zero.
Some effects such as pain, swelling, bruising and temporary stiffness are expected during recovery and do not necessarily represent complications. Other problems, including infection, blood clots, dislocation or implant-related complications, require closer attention.
The individual risk depends on factors such as age, general health, medical conditions, previous surgery, mobility, the condition of the hip and the type of procedure performed.
What are the common effects during recovery?
Several physical changes can occur after hip replacement as the tissues heal.
- Pain or soreness around the operated hip.
- Swelling around the hip and leg.
- Bruising near the surgical area.
- Temporary stiffness.
- Muscle weakness.
- Fatigue.
- Numbness around the surgical scar.
These symptoms generally improve as healing progresses. Some swelling, altered sensation or mild discomfort can persist for weeks or longer.
The main complications of hip replacement
The potential complications can be understood according to when they may occur and how they affect the patient.
1. Blood clots in the leg or lungs
A deep vein thrombosis (DVT) is a blood clot that forms in a deep vein, usually in the leg. Surgery and reduced mobility temporarily increase the risk of clot formation. In some cases, part of the clot can travel to the lungs, causing a pulmonary embolism (PE). This can become a serious or life-threatening complication.
Measures such as early movement, compression devices or stockings and prescribed blood-thinning medication may be used to reduce the risk. Possible symptoms of DVT include increasing pain, swelling or tenderness in the leg or calf. Sudden difficulty breathing or chest pain can indicate a pulmonary embolism and requires emergency medical attention.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
2. Infection
Infection can occur around the surgical wound or, less commonly, deeper around the artificial hip. A superficial wound infection may sometimes respond to antibiotics. A deep infection involving the artificial joint is more serious and can require prolonged antibiotic treatment and additional surgery.
Warning signs can include increasing redness, warmth, swelling, wound drainage, fever or pain that is becoming worse instead of gradually improving. Importantly, infection can occasionally develop after the initial recovery period, so new unexplained pain around a previously well-functioning artificial hip should be evaluated.
3. Hip dislocation
A hip replacement can occasionally dislocate, meaning the artificial ball moves out of the artificial socket. Dislocation is particularly possible during the early healing period while the tissues surrounding the joint are recovering, although it can also occur later.
A dislocated hip can cause sudden severe pain, difficulty moving the leg or an inability to bear weight. It requires prompt medical assessment and may need to be repositioned under anaesthesia. Repeated dislocation can sometimes require further surgery.
4. Difference in leg length
After hip replacement, the operated leg can occasionally feel slightly longer or shorter than the other leg. Surgeons use measurements and implant positioning techniques to achieve appropriate leg length, but a small difference may remain in some patients.
Minor differences are often tolerated or become less noticeable as the muscles and surrounding tissues adapt. In some cases, a shoe insert or raised heel may be recommended.
5. Nerve injury
Nerves around the hip can rarely be injured during surgery. Minor numbness around the scar is relatively common because small skin nerves can be affected by the incision. This is different from significant nerve injury, which can cause weakness, altered sensation or difficulty moving part of the leg.
Major nerve injury is uncommon, but when it occurs, recovery may take a long time and some effects can occasionally be permanent.
6. Blood vessel injury
Major blood vessel injury is rare, but blood vessels are located close to the hip and can potentially be affected during surgery.
If a blood vessel is injured, additional treatment may be required. The medical team monitors circulation and the condition of the leg after surgery.
7. Fracture around the implant
A fracture can occasionally occur in the bone during the operation or later around the artificial joint. Fractures occurring during surgery are uncommon and may sometimes require additional fixation. A later fracture can occur following trauma such as a fall and may require surgery depending on its location and severity.
What are the longer-term complications?
Not every complication occurs immediately after surgery. Some problems can develop months or years later as the artificial joint is exposed to everyday use.
Implant wear
Artificial hip components are designed to withstand many years of movement, but bearing surfaces can gradually wear over time. Wear may cause pain, reduced function or other changes around the artificial joint. In some cases, significant wear can contribute to loosening or other implant problems.
Implant loosening
The components of a hip replacement can occasionally become loose from the surrounding bone. Loosening may cause persistent or gradually increasing pain, particularly during weight-bearing activities. If the problem becomes significant, revision surgery may be necessary.
Repeated dislocation or instability
Some people experience recurrent instability after a hip replacement. Repeated dislocation may indicate a mechanical or soft-tissue problem that needs further assessment. If conservative measures are not sufficient, revision surgery may sometimes be considered to improve stability.
Persistent pain
Most people experience improvement in the pain caused by their original hip condition, but some patients continue to have discomfort after surgery.
Persistent pain can have several possible causes, including infection, implant loosening, instability, muscle or tendon problems, nerve-related pain or another condition affecting the back or leg.
Persistent or worsening pain should therefore be investigated rather than automatically attributed to the normal recovery process.
Can hip replacement cause heart or lung complications?
Major surgery places temporary stress on the cardiovascular and respiratory systems. People with existing heart, lung or other medical conditions may have a higher risk of complications.
Possible medical complications can include cardiovascular events, respiratory problems or, rarely, stroke. The level of risk varies considerably between patients and is assessed before surgery.
This is one reason the pre-operative evaluation is important. Your surgical and anaesthesia teams review your medical history and may recommend additional tests or treatment to make surgery safer.
Who has a higher risk of complications?
Complication risk is not the same for every patient. Factors that may influence risk include:
- Older age or frailty.
- Heart or lung disease.
- Diabetes, particularly when poorly controlled.
- Obesity.
- Smoking.
- Previous blood clots.
- Reduced mobility.
- Previous hip surgery.
- Active infection or problems affecting wound healing.
- Other significant medical conditions.
Having one of these factors does not automatically mean that hip replacement cannot be performed. Instead, the medical team considers how the factor affects individual surgical risk and whether it can be improved before surgery.
What can be done to reduce the risk?
Some risks cannot be completely eliminated, but careful preparation and postoperative care can reduce the likelihood of complications. Depending on your circumstances, preparation may include:
- Managing diabetes and other medical conditions effectively.
- Stopping smoking before surgery.
- Improving physical fitness and muscle strength where appropriate.
- Addressing active infections before surgery.
- Reviewing medications and blood-thinning treatment.
- Following instructions about blood-clot prevention.
- Beginning safe movement as advised after surgery.
- Following wound-care and rehabilitation instructions.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Which symptoms should not be ignored after hip replacement?
Knowing when to seek medical advice is an important part of recovery. Contact your medical team promptly if you develop:
- Increasing rather than improving hip pain.
- Increasing redness, warmth or swelling around the wound.
- Fluid, pus or persistent discharge from the surgical wound.
- Fever, chills or feeling unusually unwell.
- Increasing calf or leg pain and swelling.
- New or worsening numbness or weakness.
- A sudden change in the position or movement of the artificial hip.
- New difficulty bearing weight.
These symptoms do not necessarily mean that a serious complication has occurred, but they warrant medical assessment.
Can complications require another operation?
Some complications can be managed without another operation, while others may require additional surgery. For example, a superficial wound infection may respond to antibiotics, while a deep infection involving the artificial joint may require surgical treatment. A dislocated hip may sometimes be repositioned without open surgery, but repeated dislocations can require revision surgery.
Implant loosening, significant wear, certain fractures and some persistent mechanical problems may also eventually require revision hip replacement.
Revision surgery is more complex than the original replacement, which is why long-term follow-up and early assessment of new symptoms are important.
The Bottom Line
Hip replacement is generally a safe and effective operation, but it is still major surgery and complications are possible. Some effects—such as pain, swelling, bruising, stiffness and temporary numbness around the scar—are commonly part of recovery. Others, including infection, blood clots, dislocation, fractures, nerve or blood vessel injury, implant loosening and wear, require closer medical attention.
The risk is different for every patient and depends on factors such as general health, age, mobility, existing medical conditions and previous surgery. Careful preparation before the operation and appropriate rehabilitation afterward can help reduce avoidable risks.
Most importantly, symptoms that are severe, unexpected or getting worse should not simply be assumed to be part of normal healing. Early medical assessment can help identify complications and, when possible, treat them before they cause more significant problems.
