H. John Cooper, MD

Revision surgery · New York City

Revision hip and knee replacement

Surgery to repair or replace a hip or knee replacement that has become painful, loose, worn, unstable or infected.

Dr. H. John Cooper performs revision hip and knee replacement, including complex cases, at Columbia University Irving Medical Center and NewYork-Presbyterian Hospital.

Call (212) 305-6959

Midtown · Uptown · Westchester

Why a replacement is redone

Most hip and knee replacements last many years. When one stops working well, the cause decides the operation. Common reasons include:

  • Loosening or wear. The implant has come away from the bone, or the plastic liner has worn thin.
  • Infection. Bacteria have settled on the implant, which may call for removing it and treating the infection before a new one is placed.
  • Instability. The hip dislocates, or the knee feels loose or gives way.
  • Fracture around the implant. The bone has broken near the stem or components.
  • Stiffness or malposition. The joint will not move well, or a component sits in a position that causes pain.
  • Reaction to metal debris. Rarely, wear or corrosion at a junction between parts irritates the tissue around the joint.

Not every painful replacement needs surgery. Part of the first visit is working out the cause, and sometimes the answer is something other than the implant.

How the cause is found

Dr. Cooper reviews your history and current X-rays, and often your earlier operative records and implant details. If the diagnosis is not made from the exam and X-rays, additional workup may be required. This often involves advanced imaging tests and blood work, with joint fluid sampling when infection is a concern.

He has written on the diagnosis of joint infection and on corrosion-related failures, and teaches how to approach them.

Operations

The operation depends on what has gone wrong. Dr. Cooper's revision practice includes:

  • Exchange of the plastic liner or of single components when the rest of the implant is sound.
  • Full revision of the hip or knee, including cases with bone loss that need special stems, cones or augments.
  • Revision for infection, as a one-stage or two-stage exchange, with soft-tissue coverage planned with plastic surgery colleagues when the skin needs it.
  • Surgery for instability, including exchange to a more constrained insert in carefully chosen knees.
  • Treatment of fractures around a hip or knee replacement.
  • Conversion of a partial hip replacement (hemiarthroplasty) to a total hip replacement.
  • Revision of hips with corrosion at a modular junction.

For hips, Dr. Cooper performs nearly all primary and the large majority of his revision replacements through the direct anterior approach. Whether it is the right route for a given revision depends on the reason for revision and the implants already in place.

Recovery

Recovery after revision depends on how much work the operation involved. It is often longer and less predictable than after a first replacement, and your surgeon should give you a realistic timeline before surgery.

Most revisions follow the same recovery protocol as a first replacement (see Recovery on the hip and knee pages).

More complex problems are different, and the plan is tailored to the operation. Infections are also different: treatment requires consultation and co-management with an infectious disease specialist, and recovery is planned around that treatment.

Risks

Revision surgery carries the risks of a first replacement, which include infection, blood clots, fracture, nerve or blood vessel injury, a difference in leg length and stiffness. Several are somewhat more likely after revision, because the surgery is longer, the bone and soft tissue may be weaker from earlier operations, and the results are less predictable than a first replacement. A revised joint may not last as long as a first one, and some patients need further surgery.

Dr. Cooper will go through the risks that apply to your case, including what is known about results in patients like you.

Experience

Volume
38 revision or conversion hip and 29 revision knee procedures in 2026; more than 1,000 revision hip and knee procedures over his career
Training
Board-certified orthopedic surgeon; fellowship in adult reconstructive surgery at Rush University Medical Center and Central DuPage Hospital
Practice
15 years in New York City, at Columbia since 2017; Director of Research, Center for Hip & Knee Replacement
Presentations
Over 130 presentations on revision surgery, joint infection, implant corrosion, periprosthetic fracture and other failures of hip and knee replacements, at national and international meetings
Teaching
Author of book chapters on diagnosing and treating joint infection, in textbooks edited by leaders in the field

The research

Dr. Cooper has published widely on why hip and knee replacements fail and how they are treated: infection, corrosion, loosening, instability, stiffness, fractures and revision surgery. Most recent first:

Questions

How do I know whether my replacement needs revision?

Pain, a feeling of looseness or giving way, swelling, a hip that dislocates, or X-ray changes can all be reasons to look further. The cause has to be identified before surgery is recommended, and some problems can be treated without another operation.

Does the whole implant always have to be replaced?

No. When part of the implant is well fixed and working, it may be possible to replace only the part that has failed. This depends on the design of the implant and the condition of the bone.

What happens if my joint is infected?

Treatment depends on how long the infection has been present, the organism and your overall health. It can range from a washout with exchange of the removable parts to removing the implant and placing a new one in one or two stages, along with antibiotics. Dr. Cooper will explain the options for your case.

Will a revision last as long as my first replacement?

It depends on why the first one failed, the quality of the bone and the type of revision. Results are often good, but a revised joint may not last as long as a first replacement.

What should I bring to my first visit?

Bring any X-rays, MRI or CT images or reports, your operative report or implant sticker sheet from the earlier surgery if you have it, a list of your medications, and any recent blood test or joint fluid results. If you do not have the implant details, the office can help you request them from the hospital that did the surgery.

Schedule a surgical consultation

Offices are in Midtown, Uptown and Westchester. See locations.

Call (212) 305-6959