What revision surgery means

Revision hip and knee replacement surgery may change one component, exchange a worn plastic bearing or remove and rebuild the whole artificial joint. The scale of the operation depends on why the replacement has failed and on the bone, ligaments and soft tissues that remain.

There is no standard revision operation. Two patients with the same diagnosis can need very different surgery. For that reason, nothing on this page should be read as a description of what will happen in an individual case.

Why a replacement may need revision

Modern hip and knee replacements last a long time. When one does fail, the reason usually falls into one of the groups below.

How this fits into my practice

The revision surgery I undertake is predominantly for periprosthetic fractures and infection, carried out at Morriston Hospital as part of the regional service.

This work depends on the infrastructure of an NHS hospital: a full range of revision implants available at short notice, on-site microbiology, anaesthetic and critical care support, and a multidisciplinary team that meets to plan complex cases. A small number of patients are occasionally referred on to a specialist centre, such as Cardiff, where an individual case calls for it.

This page is here as general information for patients and families who want to understand the subject.

How the problem is worked out

Assessment is thorough and usually takes more than one appointment. It normally includes:

• A full history, including how the joint felt after the first operation and when the problem started
• Examination of the joint, the skin, the soft tissues and the limb as a whole
• X-rays, compared where possible with films taken soon after the original surgery
• Blood tests for markers of inflammation
• Aspiration of the joint — drawing fluid off with a needle — when infection is a possibility⁵
• Further scans in selected cases, such as CT for bone loss
• Details of the original implant, obtained from the operating hospital or the National Joint Registry

Before revision hip and knee replacement is considered, assessment aims to establish a clear reason for pain or implant failure. Guidance for problematic knee replacements sets out a structured sequence of investigations so that infection is identified or excluded before anything else is planned.^4,5 The same principle applies at the hip.

Infection around a replacement

Infection on an implant behaves differently from infection elsewhere. Bacteria form a protective layer on the metal and plastic, which antibiotics alone rarely clear. Surgery is almost always part of treatment. The British Orthopaedic Association guidance on acute periprosthetic joint infection emphasises early recognition, appropriate sampling and specialist orthopaedic review.¹

Treatment is decided jointly with microbiologists and, in complex cases, with plastic surgeons. The main approaches are:

• Debridement with implant retention. The joint is washed out, the plastic bearing exchanged and the fixed components left in place. This is generally an option only when the infection is recent and the implant is well fixed.¹
• Single-stage revision. The implant is removed and a new one put in during the same operation, under antibiotic cover.
• Two-stage revision. The implant is removed, a temporary antibiotic spacer is placed, antibiotics are given, and a new joint is put in at a second operation weeks or months later.

Which route is chosen depends on the organism, how long the infection has been present, the state of the bone and skin, and the patient's general health.² Antibiotic treatment is prolonged and is supervised by the infection team.

Periprosthetic fracture

A periprosthetic fracture is a break in the bone around a replacement. It is usually caused by a fall, often a simple one, and becomes more likely in later life and where bone is thinner.

Treatment depends on whether the implant is still firmly fixed:

• If the implant is stable, the fracture is usually fixed with plates, screws or wires, and the replacement is left alone.
• If the implant has loosened, fixing the bone alone will not work. The replacement is revised, often with a longer stem that bypasses the fracture.

These injuries are treated as urgent. National standards for frail patients and those in later life emphasise early surgery, medical input alongside the orthopaedic team, and an operation planned to let the patient get up and moving as soon as possible.^6,7 Unrestricted weight-bearing is the aim where the fixation allows it, but it is not always achievable, and any restriction will be explained clearly before you go home.

Complexity, planning and where surgery is done

Revision cases are graded for complexity. Knee cases are classified from R1 to R3, and hip cases from H1 to H3, using published systems that take account of bone loss, infection, previous revisions, the extensor mechanism and the soft tissues.^8,9

These grades exist because outcomes are better when complex work is concentrated in units that do it regularly. Formal revision networks were established in England following national review of orthopaedic services, and the British Hip Society has developed a comparable approach for revision hips.^10,11 Wales does not currently have a functioning revision network. Referral is therefore decided case by case rather than through a set pathway.

In practice, patients are referred to a larger unit when the reconstruction demands it. At the hip this is most often where extensive pelvic reconstruction is needed. That is a guide rather than a rule, and the decision rests on the individual case rather than on the label attached to it.

If your case is referred elsewhere, that is not a setback. It means the reconstruction is better done where that particular work is done often.

What the operation may involve

Revision surgery covers a wide range. At one end is a straightforward exchange of a worn plastic bearing. At the other is removal of a whole replacement, reconstruction of missing bone and implantation of a large custom component.

Features that distinguish revision from first-time surgery include:

• A longer operation, sometimes considerably longer
• The old implant has to be removed without taking more bone than necessary
• Bone loss may need filling with graft, metal augments, cones or sleeves
• Implants with longer stems, to gain fixation in healthy bone beyond the damaged area
• More constrained implants if the ligaments no longer provide stability
• A higher chance of needing a blood transfusion

Revision hip and knee replacement requires detailed planning from imaging and the records of the original operation, with alternative implants and reconstruction options available if the findings at surgery differ from what was expected.^3,12

Risks

Revision surgery carries the same risks as first-time joint replacement, but each is more likely. Bone is weaker, soft tissues are scarred, the operation is longer, and patients are more often in later life.

Recognised risks include infection, dislocation or instability, fracture during surgery, nerve or blood vessel injury, blood clots, wound healing problems, bleeding needing transfusion, leg length difference at the hip, and the possibility of further surgery in future.

National Joint Registry data show that revision joints are revised again more often than first-time replacements are.¹³ The risk of needing another operation rises with each revision. This is discussed openly before any decision is made because it changes how the balance of benefit and risk should be weighed.

Recovery

Recovery after revision is slower and less predictable than after a first replacement. Published timeframes for primary surgery do not transfer across.

What varies between patients:

• Weight-bearing. Some patients walk fully on the leg straight away. Others are restricted for weeks to protect a graft, a fixation or a reconstruction. This is decided in theatre and explained afterwards.
• Length of stay. Longer than after a primary replacement. In one major revision centre, the median stay rose from about five days for the least complex cases to about eleven days for the most complex.¹⁴
• Walking aids. Used for longer, and given up when the leg is ready rather than on a set date.
• Driving and work. Depend on the operation performed, the weight-bearing instructions and how the leg recovers. No single figure applies.
• Antibiotics. If infection was treated, these may continue for a prolonged period after discharge, with monitoring.

Physiotherapy is tailored to the reconstruction. Follow-up is usually closer and longer than after a first replacement, with repeated X-rays to check that fixation and any graft are behaving as expected.

What to expect from the result

Most patients gain worthwhile pain relief and improved function after revision hip and knee replacement. On average, the improvement is smaller than after a first-time replacement, and the joint is less likely to feel entirely normal.

Setting expectations honestly at the outset matters more here than almost anywhere else in joint replacement surgery. A realistic goal — walking comfortably to the shops, sleeping without pain, keeping independence — is usually achievable. A return to a joint that feels as it did at twenty is not.

Questions worth asking

• Why is my replacement failing, and how confident are you in that diagnosis?
• Has infection been excluded, and how?
• What will the operation involve, and what is the plan if you find something unexpected?
• Will I be able to put weight on the leg straight away?
• How complex is my case, and who else will be involved in planning it?
• Would this reconstruction be better done in a larger unit?
• What are the realistic chances of needing further surgery?
• What happens if I decide not to have the operation?

References

1. British Orthopaedic Association. Acute Management of Peri-Prosthetic Joint Infection (BOASt). October 2023.
2. British Orthopaedic Association. Peri-prosthetic Joint Infection (Specialty Standard, SpecS). April 2024.
3. British Orthopaedic Association and British Association for Surgery of the Knee. Revision Total Knee Replacement Surgical Practice Guidelines (BOASt). August 2020.
4. British Orthopaedic Association and British Association for Surgery of the Knee. Investigation and Management of Patients with Problematic Knee Replacements (BOASt). August 2020.
5. British Orthopaedic Association and British Association for Surgery of the Knee. Investigation and Management of Prosthetic Joint Infection in Knee Replacement (BOASt). August 2020.
6. British Orthopaedic Association. Mobilisation and Weightbearing after Orthopaedic Surgery or Musculoskeletal Injury (Process BOASt). August 2024.
7. British Orthopaedic Association and British Geriatrics Society. The Care of the Older or Frail Orthopaedic Trauma Patient (Process BOASt). May 2019.
8. Phillips JRA, Al-Mouazzen L, Morgan-Jones R, Murray JR, Porteous AJ, Toms AD. Revision knee complexity classification (RKCC). Knee Surgery, Sports Traumatology, Arthroscopy 2019;27(4).
9. Development of the Revision Hip Complexity Classification using a modified Delphi technique. Bone & Joint Open 2022;3(5).
10. British Hip Society. Setting up revision hip networks: the British Hip Society approach. Journal of Trauma and Orthopaedics, British Orthopaedic Association.
11. Getting It Right First Time (GIRFT). Orthopaedics: National Specialty Report, recommendations on networked provision of revision arthroplasty.
12. Getting It Right First Time, British Hip Society and British Orthopaedic Association. Best Practice for Hip Arthroplasty Surgery Documentation.
13. National Joint Registry for England, Wales, Northern Ireland, the Isle of Man and the States of Guernsey. 22nd Annual Report, 2025. Reporting period 1 April 2024 to 31 March 2025.
14. Complexity of revision total knee arthroplasty at a major revision centre. Orthopaedic Proceedings, British Association for Surgery of the Knee meeting, 2022.

All guidance documents and registry data accessed 11 September 2026.