What is Periprosthetic Proximal Femur Fractures?
Total hip replacement surgery (or THA) is a reliable option for people suffering from severe hip arthritis. Thanks to medical advancements, patients going through this surgery experience better results with shorter hospital stays. A collaborative effort with the anesthesia team has improved the management of pain before, during, and after the surgery, reducing the need for strong painkillers.
Before the surgery, the primary care team works closely with each patient to prepare them for the operation or to postpone it for those who are not healthy enough to go through with it. Now, thanks to better patient screening and the availability of artificial joints, a wider age range of patients can undergo hip replacement surgery, often as an outpatient procedure.
Given these improvements, the demand for hip replacement surgeries is predicted to surge by 174%, from 329,000 to 572,000 operations by 2030 compared to the figures from 2005.
As the focus on individual health and preventive medicine increases, along with medical advancements, patients are living longer than ever before. Consequently, more and more people require hip replacement surgeries. This increase has also led to a rise in complications like fractures around the artificial joint.
Operating on these fractures can be challenging, making it crucial that they’re performed by surgeons with considerable experience in this field and a deep understanding of the surgical planning complexities.
What Causes Periprosthetic Proximal Femur Fractures?
Periprosthetic fractures – these are fractures that occur around joint implants – are more common in certain groups. These include:
* Women, who may have hormonal imbalances
* People with weak or thinning bones (osteoporosis and osteopenia)
* People with diseases affecting the nervous system and muscles, such as Parkinson’s disease, epilepsy, and ataxia
* People with cognitive disorders like dementia
* People taking certain medicines, including long-term use of steroids
* People with joint inflammation diseases like rheumatoid arthritis and osteoarthritis
* People with infections
* People who have had a total hip replacement, especially if it was done aggressively or has caused stress shielding.
* The type of joint implant used can also affect the risk of fractures. Some implant factors include the level of constraint and wear of polyethylene (a type of plastic used in implants).
Risk Factors and Frequency for Periprosthetic Proximal Femur Fractures
Periprosthetic proximal femur fractures, or breaks in the upper leg bone near a prosthetic joint, can happen in 0.1 to 18% of cases. Certain factors may increase the risk of these fractures. For instance:
- Revision arthroplasty, a surgery to replace a worn-out prosthetic joint,
- The surgical technique used,
- And the type of implant.
A study by Canton et al. found that complicated surgeries like revision of a total hip replacement can increase the risk of fracture to 4 to 11% due to the intense procedure and high need for tissue and bone handling. In comparison, another study by Kurtz et al. pointed out that factors like inadequate bone stock, over-enthusiastic bone preparation and a mismatch between the prosthetic piece and patient’s anatomy can make the risk of fracture during a primary hip replacement surgery around 1.7%. They also found that issues like continued bone loss, bone weakening (osteolysis) and stress shielding, where the implant takes most of the force instead of the bone, can increase the chance of a fracture after 20 years of a primary hip replacement to 3.5%.
Signs and Symptoms of Periprosthetic Proximal Femur Fractures
Periprosthetic fractures mainly occur when people are going about their daily routines, and they don’t often involve any significant trauma. If you look into these patients’ medical histories, you’ll often find that they have a history of fragility fractures. People’s experiences with this condition can vary significantly. For instance, some people may experience severe thigh or leg pain and may not be able to walk, while others might experience a more mild, vague thigh pain and can still walk. When examining the patient, it may not be obvious that a fracture has occurred because the femur is surrounded by a lot of soft tissue. It’s rare for these types of fractures to result in nerve or blood vessel damage, but doctors will evaluate and document this in every orthopedic patient in any case.
Testing for Periprosthetic Proximal Femur Fractures
When diagnosing a fracture around the artificial joint in the upper part of the thigh bone (a periprosthetic proximal femur fracture), your doctor will first conduct an x-ray of the entire leg, stretching from the hip to the ankle. Getting a clear view of both the hip and knee is crucial, as it assists the doctor in deciding which types of medical implants can be used in treating the fracture.
Sometimes, the standard x-ray images of the hip may not provide sufficient information for proper planning. In such cases, the doctor may order a computed tomography (CT) scan, which offers a more detailed view and the possibility of 3D reconstruction. Knowing about any previous surgeries or being able to recognize the appearance of standard joint replacement implants on x-rays can greatly aid in preoperative planning.
In order to manage the fracture, the surgeon should be comfortable in performing various surgical treatments. These can include securing the fracture in its original position (in-situ fixation), replacing the broken part of the femur (revision femoral arthroplasty or proximal femoral replacement), and in rare cases, removing the ball of the hip joint (Girdlestone resection arthroplasty).
In orthopedics, fractures are typically classified using special systems, which help doctors to determine the best treatment method. One reliable system used for periprosthetic femur fractures is the Vancouver classification. It guides the doctor’s decision on treatment based on the location, pattern, and stability of the fracture and the stability of the artificial joint and quality of the surrounding bone. According to this system, fractures are categorized as either A, B, or C, and then further divided based on the fracture pattern.
In the intraoperative Vancouver Classification, for example, category A involves fractures in the upper part of the bone. B involves fractures in the shaft of the bone while C involves fractures in the lower part of the bone. Each category is then broken down into subcategories, representing perforated, nondisplaced, and displaced/unstable fractures, respectively.
The postoperative Vancouver Classification considers fractures in the region around the hip, fractures around the artificial joint, and fractures further down the thigh bone. Again, these categories are divided into subtypes.
This thorough evaluation and classification system ensures the most effective treatment plan is chosen for each specific case of periprosthetic femur fracture.
Treatment Options for Periprosthetic Proximal Femur Fractures
For instant treatment of injuries with a threat to the soft tissues or circulatory delievery systems, immediate stabilization of the bones is necessary. This can be achieved either through applying traction or using an external fixture. For stable fractures without risk to the soft tissue or circulation, immobilization and restrictions on weight-bearing can be applied through methods like splinting or using a knee immobilizer.
Postoperative fractures near a prosthetic device are often dealt with in a non-surgical manner, especially for patients who are not fit for another surgery. This requires a period of non-weight bearing and careful monitoring of soft tissues. Educating the patient regarding the potential complications such as poor healing or misaligned healing, and skin discomfort, is crucial.
Fractures near a hip replacement are often surgically fixed. Options include using trochanteric claw plates for additional fixation. A balance in weight-bearing is advised, along with some form of support like a brace, for up to three months, or until fracture callus is present.
Second type of fractures occurring around or just below a hip prosthesis can be treated by aligning the bones and fixing them in place with plates. The number of screws used in the plate also depends on the location of the fracture. More stable fixation may require augmentation with cerclage wiring and grafting. Weight bearing is not advised until the fracture callus is seen. Also, note that these type of fractures poses significant medical concern due to increased length of hospital stay and a high rate of failure with internal fixation alone.
Finally, fractures that occur far from the prosthesis can be stabilized with the use of bone grafting or a fitting prosthesis. Additionally, fractures distal to the prosthesis can be managed with internal fixation using a variety of plate fixation methods. For intraoperative fractures, certain treatments like cerclage wiring, bone grafts or insertion of a femoral stem can be used depending on the location and type of fracture.
What else can Periprosthetic Proximal Femur Fractures be?
Before doing any X-rays or other scans, the doctor will consider a number of potential diagnoses. These might include:
- A fracture around the area of an artificial joint
- The artificial joint becoming loose, not due to an infection
- An infection in the prosthetic joint
- An injury to the ligaments
- A fracture in the metal or plastic prosthetic joint
- A bruise
- A dislocation of the hip
- A blood clot in a vein, also known as venous thromboembolism
- A fracture that can’t be seen on initial scans, known as an occult fracture
- Metallosis, which is a reaction to metal debris, often from a metal prosthetic joint
Taking these possibilities into account, the physician can then carry out the necessary tests to pinpoint what exactly is causing the patient’s symptoms.
What to expect with Periprosthetic Proximal Femur Fractures
Drew and his team compared the death rates for fractures in the area near the prosthetic upper leg bone and hip fractures. In their review of 291 patients, they discovered that within a year, 24% of patients had died – a number not far off from the 30% one-year mortality rate that’s typically associated with hip fractures.
Another study led by Zheng emphasized the complexity of these surgeries and how they impact patient mortality and long-term health. The study found that, even with successful surgeries, patients often have a hard time recovering fully and frequently face unfavorable outcomes.
Possible Complications When Diagnosed with Periprosthetic Proximal Femur Fractures
Breaking the area near the hip prosthesis, or a periprosthetic proximal femur fracture, can be a difficult issue to manage and often comes with complications. A study by Lindahl and colleagues mentioned an overall complication rate of 18%, with 23% of these patients requiring more surgeries in future. They observed that in 24% of the cases, the bone didn’t heal properly (nonunion), and in a similar percentage, the bone broke again (refracture).
Apart from this, other complications like delayed healing of bone, failure of surgical hardware, hip dislocation, damage to nerves or blood vessels, issues with the surgical wound, and infections were also noticed. Another study by Henderson and team quoted an infection rate of up to 9% in cases where the original fracture was fixed in place with surgical plates. This type of surgery usually requires more invasive techniques and causes more trauma to the bone and soft tissue.
Klein and team also found that there’s a 21% chance of hip dislocation after the hip joint is replaced again due to the surrounding muscle complex being weakened.
Common Complications:
- Requiring more surgeries
- Bone not healing properly
- Bone breaking again
- Delayed healing of bone
- Failure of surgical hardware
- Hip dislocation
- Damage to nerves or blood vessels
- Issues with the surgical wound
- Infections
- Hip dislocation after the hip joint is replaced again
Recovery from Periprosthetic Proximal Femur Fractures
Using a diaphyseal fit stem for revision arthroplasty has been successful in reducing the number of patients who need to limit their weight-bearing activities significantly. The aim of this treatment is to secure the fracture, enabling the patient to walk unaided as soon as possible. A study by Mulay and colleagues recommended that those experiencing specific thigh bone (femur) fractures around the prosthetic joint and treated solely with plate fixation should limit their weight-bearing activities for six to twelve weeks. This also applied to certain types of fractures (Vancouver B and C) which needed surgical fixation in addition to revising the hip replacement. The study recommended a slow increase in weight-bearing, starting with toe-touch weight-bearing at six weeks, gradually increasing until the patient can bear their full weight by three months.
Post-surgery, the condition of the hip abductor muscles can impact the patient’s gait, possibly resulting in a permanent Trendelenburg gait (where the hip drops on the side of the body opposite from the one bearing weight). Some patients may need to aid their balance with a cane in the opposite hand. In addition, keeping a patient immobilized after surgery can significantly increase the risk of complications related to surgery, which is why one of the main reasons for surgery is to avoid this limitation.
Preventing Periprosthetic Proximal Femur Fractures
Regular check-ups for older adults with their main healthcare provider should prioritize preventing falls and boosting bone health through physical activity and drugs. Paying careful attention to the condition of the bones can help avoid the serious complications that come with a fragility fracture. If an elderly patient experiences this type of bone break, they should see a general or specialty doctor who focuses on rheumatology. These doctors can help manage the patient’s bone health and put together a plan to lower the chances of more fractures in the future.
