Hip and knee replacement: common questions

No single approach is best for every patient. The majority of studies show slightly quicker early recovery, slightly less postoperative pain, and a clear lower risk of prosthetic dislocation with the anterior approach. However, long-term results are generally similar when the surgeon is experienced and proficient with the technique they use.

It works between muscles instead of splitting them, but "no muscle cut" overstates it. Some soft tissue, often one or more of the short external rotators, may be released when contracted to expose the joint safely.

It is on the front of the hip and typically about 8-12 cm long. A bikini-line version, which Dr. Cooper uses the majority of the time, is described below.

The bikini incision is a short cut, about 8-12 cm depending on body habitus, that follows the natural skin crease at the front of the hip. The traditional incision for the direct anterior approach runs in a straight line along the length of the thigh bone.

The skin at the front of the hip is under tension that runs side to side, and a straight incision cuts across those lines. It has to be closed under more tension, which can contribute to wound healing problems, especially in patients with a higher body mass index. The bikini incision runs along the lines of the groin, so it closes under less tension and is expected to leave a narrower, more cosmetically favorable scar with a lower chance of the top layer of the wound separating.

There are trade-offs. The bikini incision is less easy to extend if more exposure is needed, so is best performed by experienced anterior hip surgeons where there is less risk of surgical complications. Dr. Cooper has published studies finding it safe and effective for direct anterior hip replacement. Whether it is the right choice for you depends on your anatomy and skin creases, and he will go over it with you.

Dr. Cooper's patients go home either the same day as surgery or the next morning, depending on the patient and the plan made beforehand.

A stay in a rehabilitation facility or nursing home after hospital discharge is strongly discouraged, to avoid a higher risk of postoperative complications. It is rarely recommended, and only for elderly, frail patients who do not have a support system at home.

In experienced hands it is used for some revisions. Whether it suits a given revision depends on why the first replacement is being redone and on the implants already in place. Dr. Cooper performs nearly all primary and the large majority of his revision hip replacements through the direct anterior approach.

Bring any X-rays, MRI or CT images or reports, a list of your medications, and records of previous surgery on the hip or leg.

No. The surgeon plans and performs the operation. The robotic arm keeps the saw within the planned limits, and the surgeon is in control throughout.

Robotic assistance improves the accuracy of bone cuts and implant position. Evidence that it leads to better long-term results is still developing, and conventional knee replacement also works well. Dr. Cooper finds that robotics allows him to personalize the operation to each patient and deliver a more individualized result, which is why he prefers to use it in the vast majority of cases.

It depends on the robotic system and your knee. Dr. Cooper and his team will let you know if you need one.

Dr. Cooper's patients go home either the same day as surgery or the next morning, depending on the patient and the plan made beforehand.

A stay in a rehabilitation facility or nursing home after hospital discharge is strongly discouraged, to avoid a higher risk of postoperative complications. It is rarely recommended, and only for elderly, frail patients who do not have a support system at home.

Most knee replacements last many years, and many last 20 years or more. How long yours lasts depends on your activity, weight, bone quality and the implant.

Yes, for patients whose arthritis is limited to one part of the knee. A full examination and X-rays show whether a partial or total replacement is the better choice.

Bring any X-rays, MRI or CT images or reports, a list of your medications, and records of previous surgery on the knee or leg.

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.

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.

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.

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.

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.

No. You can start with nonoperative care, and Dr. Cooper supervises the plan. Dr. Cooper is available to see patients for their first consultation, which is the preferred route if surgery is planned.

Many patients choose to schedule their first consultation with Madison Lucido or Chloe Beam instead, because access is easier and quicker. If nonoperative treatment is appropriate, it can be started immediately.

If surgery is more appropriate, Dr. Cooper is often available the same day in the office, or the next day by telehealth, to meet with you.

No. Injections can reduce pain and help you stay active, but they do not reverse arthritis. How long relief lasts varies from person to person. Injections rarely work well for advanced arthritis.

No. PRP is a cash-pay treatment, usually around $1,000, and insurance does not cover it. For knee arthritis, a recent meta-analysis of randomized trials found that PRP gave better pain and function scores than hyaluronic acid (gel) injections at 6 and 12 months (Bagheri et al., Journal of Experimental Orthopaedics, 2025).

They can affect timing. Dr. Cooper recommends a gap of 3 months between a joint injection and replacement surgery because of a small increase in the risk of infection. In rare circumstances the gap is shortened when the benefits of earlier surgery outweigh that small increase. Tell your team about any injections you have had.

Bring any X-rays, MRI or CT images or reports, a list of your medications, and a list of treatments you have already tried, including therapy and injections.