An artificial hip joint improves the quality of life for millions of people worldwide. However, despite all advances in endoprosthetics, complications can occur, including so-called periprosthetic fractures. These fractures in the immediate vicinity of the prosthesis can arise from different reasons and pose a major challenge for physicians and patients. Especially with short-stem prostheses, specific biomechanical factors must be considered that influence the fracture risk. In this article, we will examine in detail the causes, diagnosis, treatment options, and prevention of periprosthetic fractures in short-stem prostheses.

What are periprosthetic fractures?

Periprosthetic fractures are bone fractures that occur in the area of an already implanted artificial joint. These fractures typically occur in the vicinity of the prosthetic stem anchorage and can occur both intraoperatively and postoperatively.

Classification of periprosthetic fractures

Periprosthetic fractures are classified according to different systems. The commonly used Vancouver classification system divides fractures into:

• Type A: Fractures of the greater or lesser trochanter (usually treated conservatively)
• Type B1: Fractures in the area of the prosthesis stem with stable prosthesis
• Type B2: Fractures with loosening of the prosthesis
• Typ B3: Fractures with poor bone qualität
• Type C: Fractures below the prosthetic shaft

The distinction between these fracture types is crucial for the choice of treatment method.

Why do fractures occur with short-stem prostheses?

Short-stem prostheses are designed to enable bone-sparing implantation as much as possible. The fixation is primarily done in the proximal femur, which results in a different distribution of stress and force compared to conventional long-stem prostheses.

Factors that increase the risk of fracture:

• Improper loading after surgery: An incorrect load in the first weeks after implantation can increase the risk für microfractures erhöhen
• Insufficient primäre anchorage: A poor fit or a non-optimal positioning of the implant can affect bone stabilität beeinträchtigen
• Age and bone density of the patient: Patients with osteoporosis have an höheres risk für periprosthetic fractures
• Stürze and trauma: Direct Stöße or Stürze können cause a fracture in the prosthetic area

Risk factors for periprosthetic fractures in short stem prostheses

Patient-related factors:

• Osteoporosis or other diseases with reduced bone density
• Advanced age
• Lack of muscle mass and poor balance
• Inadequate postoperative rehabilitation

Implant-related factors:

• Insufficient bony integration of the prosthesis
• Choosing a prosthesis that is too small or too large
• Use of a design that is not optimally adapted to the patient

Surgical factors:

• Careless intraoperative manipulation of the bone
• Inadequate fixation of the prosthesis
• Use of unsuitable approaches (minimal versus conventional incisions)

Differences in periprosthetic fractures between short stems and straight stems

1. Different anchoring in the bone

• Short‑stem prostheses are anchored metaphyseally, i.e., in the upper part of the femur. Thus the diaphysis (the long shaft portion of the femur) remains largely intact.
• Straight‑stem prostheses however extend deeper into the diaphysis and are firmly anchored there.

This different anchorage influences the type of fractures:

• With short‑stem prostheses, fractures tend to occur in the proximal (upper) thigh region, especially when the metaphyseal anchoring is not optimal.
• In straight stem prostheses, fractures often occur in the diaphysis, i.e. further down the femur. These fractures are more difficult to treat as they are often associated with a renewed, deep anchoring of the implant.

2. Stability and bone reserves

• A advantage of the short-stem prosthesis is that, due to the kürzere anchoring in the bone, more bone substance is preserved. This can be helpful in a fracture, as more bone material für operative stabilization is available.
• With straight-stem prostheses a periprosthetic fracture can be more critical, because the bone structure has been stärker verändert by the long anchoring and often fewer bone reserves are available.

3. Risk in the event of falls and accidents

• Straight-stem prostheses erhöhen the risk für distal fractures (deeper located femur fractures), because the rigid, long anchoring transfers Hebelkräfte to the lower part of the femur bone überträgt.
• Short-stem prostheses generally have a lower risk for such distal fractures, as they are shorter and the force impact remains limited to a smaller bone region.

4. Treatment options for fractures

• In fractures around a short-stem prosthesis it is often possible to treat them with plate osteosyntheses or other stabilizing measures, without having to replace the prosthesis.
• In fractures around a straight-stem prosthesis a switch to a longer-reaching, axis-guided or modular revision prosthesis is more often necessary.

5. Are short stem prostheses advantageous?

• Short-stem prostheses show a lower risk for serious diaphyseal fractures, as the bone structure remains largely preserved.
• When fractures occur, they usually occur near the proximal bone, which offers better treatment options.
• Straight-stem prostheses, on the other hand, have a höheres Risiko für Frakturen im mittleren und unteren Oberschenkelbereich, which are more difficult to treat.

Overall, short-stem prostheses offer certain advantages with regard to periprosthetic fractures, particularly in terms of bone preservation and treatment options in the event of a fracture.



Diagnosis of a periprosthetic fracture

A quick and accurate diagnosis is essential to initiate adequate treatment. Typical symptoms include sudden pain, swelling, and limited mobility of the affected leg.

Diagnostic procedures:

1. X-ray images for locating the fracture
2. Computed tomography (CT) for better visualization of fractures and implant position
3. Magnetic resonance imaging (MRI) when soft tissue injury is suspected

Treatment options for periprosthetic fractures

The therapy is based on the fracture type, the stability of the prosthesis, and the bone quality of the patient.

Conservative therapy

• Only applicable for stable fractures without prosthesis loosening
• Immobilization through partial weight-bearing and physiotherapy

Operative Therapy

1. Osteosynthesis: Screw fixation or plate osteosynthesis for stable prostheses
2. Revision prosthesis: If the prosthesis is loosened or a massive Knochenschädigung is present
3. Bone transplantation or augmentation procedures: For severe osteoporosis or bone loss

Prevention of fractures with short stem prostheses

Since periprosthetic fractures represent serious complications, preventive measures are essential.

Selection of the correct implant

• Individual adaptation to the patient's bone anatomy
• Use of modern implants with optimized anchoring

Optimization of bone density

• Osteoporosis medication and vitamin D supplementation
• Strength training to strengthen the muscles

Patient behavior after surgery

• Prevention of falls through balance training
• Adherence to the recommended postoperative load limits

Conclusion and Recommendation

Periprosthetic fractures represent a serious complication in endoprosthetics. Especially with short-stem prostheses, individual adaptation to the patient is crucial to minimize the risk. Modern implants and improved surgical techniques have reduced the occurrence of such fractures, yet precise diagnostics and treatment remain essential.

Patients who require a hip replacement or are already wearing an implant should consult specialized centers to achieve the best possible results. The combination of precise surgical technique, high-quality implant selection, and adapted rehabilitation minimizes the risk of complications and improves long-term results for the patient.