How do You Fix a Loose Hip Replacement? What Studies Say

What is hip replacement loosening?

Loosening of a hip replacement can occur following the placement of a hip joint replacement. It typically occurs or is observed several years after the prosthesis is implanted.

What exactly is it?

It’s when the part of the hip replacement implanted in the thigh bone (femur) or hip (iliac bone, the acetabulum) becomes detached or loosened from the bone, no longer securely in place.

This can happen whether you have a total or partial hip replacement (also called an intermediate one), but it tends to occur more often with total replacements.

It’s not something that happens all the time. Some people can keep their prosthesis for 15 or 20 years without experiencing this issue.

Loosening is not just a simple wear and tear of the replacement. It involves the actual separation or detachment of the prosthesis that has been secured, often with a type of cement, and firmly implanted into the bone.

Sometimes, it’s referred to as ‘acetabular loosening.’ This occurs when the part of the replacement in the acetabulum (the pelvic bone) becomes detached.”

⚠️ Hip replacement dislocation and loosening are two different things.

There can be a dislocation in addition to a loosening. There can be a hip loosening without dislocation.

What are the symptoms of loosening hip replacement?

There are not yet precise and consensus criteria that definitively diagnose the loosening of a hip replacement. Indeed, loosening is not immediately visible on an X-ray.

Here are the most common symptoms:

• Severe and unusual pain
• Sensation of hip instability
• Difficulty performing certain activities that were manageable before.

However, the presence of these symptoms does not necessarily indicate loosening. Some people have no symptoms even though their replacement is loosened; they are said to be asymptomatic.

Source: Mjöberg 2021

And the diagnosis of a hip replacement loosening?

Diagnosing hip osteoarthritis or a fracture of the hip is done “easily.” X-rays and a simple clinical examination are often sufficient, and there are few false positives and false negatives.

But it is more complicated to definitively diagnose loosening, especially if there is no infection (a common cause of loosening).

The diagnosis of aseptic loosening involves:

• a thorough medical history (= a lot of questions are asked, your medical record is carefully examined),
• a targeted clinical examination;
• a comprehensive evaluation of imaging. X-rays, especially, but sometimes a CT scan, an MRI, and other types of imaging.

In some individuals, questioning and physical examination may be the only obvious initial signs of loosening. That’s why persistent, unexplained, and highly disabling pain can sometimes be an indication for revision surgery (=replacement of the implant).

Source: Anil 2022

Pain = necessarily replacement loosening?

No, having hip pain after the operation doesn’t necessarily mean replacement loosening! There are many more common causes of hip pain after the operation than loosening.

Six months after hip replacement surgery for osteoarthritis:

• 1 out of 3 people have no pain at all;
• 1 out of 2 people have only mild pain.

This means that 2/3 of people still experience pain, but not necessarily associated with loosening, as the frequency of replacement loosening is much lower.

You can find more information on thigh and hip pain after hip replacement in another article.

Source: Ninomiya 2020

What are the causes of replacement loosening?

The main described causes of hip replacement loosening are:

Most commonly, inadequate initial fixation of the replacement (in 76% of cases): osseointegration (integration of the new material into the bone) did not occur properly. This is called aseptic loosening.

It can be due to:

• poor biocompatibility of implants,
• implant surface and design,
• bone quality,
• surgical technique,
• loading conditions (rehabilitation and resumption of daily life),
• and insufficient bone renewal

Loss of mechanical or biological fixation over time, possibly related to a fall

Infection.

The mechanism is as follows: bacterial proliferation > persistent inflammatory response > implant loosening. The rate of prosthetic infection is between 0.6% and 1.3%. And the loosening rate in case of infection is 60%. Source: Dapunt 2016

In most cases, the etiology is multifactorial: several causes are likely responsible for loosening.

Source: Anil 2022; Apostu 2018

What is the treatment for replacement loosening?

The normal lifespan of a hip replacement is 10 to 25 years. But sometimes it needs to be replaced earlier, especially in the case of loosening.

If a replacement is loosened, the only possible treatment is surgery: it’s called a revision surgery.

There are different surgical techniques.

This will depend on the condition of your replacement and the remaining bone, your overall health, whether there is an infection or not, and the surgical team’s practices.

In any case:

• you will be anesthetized;
• a surgeon removes the old replacement, taking out the loosened or damaged parts of the stem and hip socket component;
• if an infection is present, the surgical team cleans the infected area;
• a new replacement is implanted into the hip bone. The new replacement can be a total or partial replacement;
• if you have significant bone loss, surgeons may perform a bone graft. In such cases, it is referred to as hip replacement revision with bone graft. It can be an artificial graft or one that comes from another part of your body;
• it is sometimes also necessary to stabilize this new replacement by adding screws or other materials to the bone.

Afterward, you will have specific postoperative instructions. For example, if you had a bone graft, you will likely be asked not to put weight on the operated leg for a month and a half.

To avoid damaging the graft.

These instructions are written in the operative report or the hospitalization report. A letter addressed to your general practitioner and physiotherapist is generally also provided and includes these instructions.

What rehabilitation and physical therapy are recommended following hip replacement loosening?

The rehabilitation of a hip replacement revisited after loosening is similar to the rehabilitation after the initial hip replacement.

Physical therapy sessions are often prescribed, to be done either in a clinic or with a home-based physiotherapist. Sometimes, a stay in a rehabilitation center is possible, especially if you have had a bone graft.

The main goal of rehabilitation is to help you quickly regain all your daily activities. To achieve this, your physiotherapist will:

• address your questions;
• provide personalized advice on what to do, what to avoid, and how to relieve your pain; encourage you to resume as many activities as possible that involve all your muscles and cardiovascular system: walking within an appropriate range, with suitable technical assistance;
• ascending and descending stairs;
• functional exercises such as sitting and standing, hip bridges; and possibly other exercises depending on the difficulties you encounter.

Apart from any limited weight-bearing, there are no additional risks or special precautions to take during rehabilitation.

The recovery time may be slightly longer, but some people return to their preoperative lifestyle within a few weeks.

How to prevent loosening of a hip replacement?

Here are the factors on which one can potentially act to limit the risk of hip replacement loosening, whether you already have a hip replacement or even before undergoing surgery for hip osteoarthritis.

• Lose weight if you are obese
• Address any osteoporosis, cardiovascular disease, or mental health issues
• Avoid tobacco consumption
• Avoid medications that can harm implant osseointegration (nonsteroidal anti-inflammatory drugs = NSAIDs)
• Avoid activities with a high impact (such as jumping, running, especially downhill). See my more comprehensive article on sport after hip replacement.

These measures help protect the implant (the hip replacement).

Source: Apostu 2018