Periprosthetic fracture

What is a periprosthetic fracture?

A periprosthetic fracture is a bone fracture occurring near a prosthesis. Since hip and knee protheses are the most common kind, periprosthetic fractures frequently affect the femur, particularly the distal part. Much less common are periprosthetic fractures affecting the hip socket (acetabulum), tibia and patella.

After the initial implantation of an artificial hip, the incidence of a periprosthetic fracture is around 1-4%, whereas the incidence for an artificial knee is estimated at 0.3-5.5%. The rates are significantly higher after revision procedures. The number of periprosthetic fractures more than doubled between 2009 and 2019, due to the increased life expectancy and physical activity levels in older age, resulting in higher numbers of prosthetic implants. The number is expected to increase to 174% by 2030.

What are possible causes fractures near an implant?

There are two incidence peaks for periprosthetic fractures, each with different associated causes. The first peak occurs in younger populations aged under 60. In these cases, the fracture results from a high-impact trauma e.g., traffic accidents. Concomitant injuries affecting nearby ligaments, tendons, menisci, and or other bones are more common in this group.

The second peak occurs in patients aged 80 and over. Common causes affecting this age group include:

• poor bone quality (e.g., due to osteoporosis, rheumatic diseases, steroids etc.)
• Prothesis loosening
• Tendency to fall (e.g., due to dizziness, muscle weakness, Parkinson’s diease, gait instability etc.)

It is quite common for a combination of these factors to be present. In this patient group, bone fractures occur without an adequate trauma or by low-impact accidents. Therefore, concomitant injuries are significantly less common.

What symptoms and clinical signs indicate a periprosthetic fracture?

A periprosthetic fracture presents with the same symptoms as other bone fractures. Uncertain fracture signs, which may occur around a fracture but don’t provide sufficient proof can be differentiated from definitive fracture signs. Usually, not all signs are present at the same time.

The uncertain fracture signs include:

• pain
• swelling
• redness
• impaired function

The definitive signs include:

• malalignment
• excessive mobility
• gap formation in the bone
• crepitus (a crackling sound produced when broken bone fragments rub against each other)

How is a periprosthetic fracture diagnosed and what examinations are necessary?

If a fracture is suspected, a thorough medical history is taken about the accident mechanism, symptoms and relevant pre-existing conditions, followed by a physical examination and radiological imaging methods. In most cases X-rays are sufficient, whereas a computed tomography (CT) scan is more suitable for complex fractures. Additional imaging methods, for instance magnetic resonance imaging (MRI) are only indicated for specific enquiries, for example, suspected soft tissue injuries.

In the case of a periprosthetic fracture, the entire prothesis must be visualized by the radiologic modality of choice. Furthermore, a so called prothesis history is taken to assess whether the prothesis can be preserved or must be replaced. To make this decision, factors including the prothesis model, prothesis age, previous imaging, and signs of prothesis loosening during postoperative care must be considered.

What treatment options are available?

The treatment of periprosthetic fractures is more complicated compared to other types of fractures, as native bone and prosthetic parts must be reconstructed in an anatomically correct, functional and stable manner.

Fractures that are not near a prothesis and are without displaced bone fragments, can often be treated conservatively. The area is immobilized, and surgery is not necessary, allowing the bone to heal naturally. In contract, periprosthetic fractures that are treated conservatively present with significantly poorer functional outcomes, often resulting in subsequent surgical revision. Therefore, periprosthetic fractures should generally be treated surgically. Only in specific cases conservative treatment may be considered, for example pre-existing conditions associated with a particularly high surgical or anesthesia risk.

Ideally, surgery should be performed within the first 48h after the accident, as delays have shown a significantly increased mortality rate.

The fracture site is accessed by a large skin incision, under general or region anesthesia. Bone fragments are repositioned into their physiological alignment if necessary. If the prothesis is stable, it can remain in place. However, if it is loosened, affected parts of the implant or the entire prothesis must be replaced. The broken bone fragments are stabilized in the correct position using screws and/or plates. If the bone quality is poor, such as in patients with osteoporosis, anchoring of the osteosynthesis materials and the prothesis poses a particular challenge to the surgeon. In these cases, bone augmentation harvested from the patient’s iliac crest, or alternatively from a donor or animal, may become necessary. Furthermore, the tissue layers are closed over the bone and the skin is sutured or stapled.

How does recovery and rehabilitation look?

Following surgery, the level of physical load must be gradually increased under physiotherapeutic supervision. Therefore, prophylaxis against thrombosis is required, typically administered through subcutaneous injections. The wound dressing must be changed regularly and the surgical frequently inspected.

A rehabilitation program can help with achieving the best possible functional outcome. Overall, approximately 70% of patients regain their previous level of mobility, prior to the fracture.

Which physicians are specialists for treating periprosthetic fractures?

A periprosthetic fracture is a trauma-surgical condition that should be treated only by experienced trauma and orthopedic surgeons as it often involves complex surgical procedures and the care of elderly or multimorbid patients.

When seeking medical care, patients naturally wish to receive the best possible medical care. Naturally patients ask themselves: Where can I find the best clinic for me? Since this question cannot be answered objectively as no reputable physician would claim to be the best, patients must rely on the physician’s extensive experience.

We help you find an expert for your condition. All listed physicians and clinics have been carefully selected based on their proven expertise in the field of periprosthetic fractures and are ready to receive your consultation request.