Short stem hip replacement, or short stem total hip arthroplasty (THA), involves using a shorter femoral stem in hip replacement surgery, aiming to preserve bone stock and achieve a more natural load transfer compared to traditional longer stems.
Here’s a more detailed explanation:
- What it is:Short stems are femoral implants designed to be shorter than conventional stems, typically with a length of 120 mm or less (measured from the center of the head to the prosthesis tip).
- Why they are used:
- Bone Preservation: Short stems are designed to minimize bone removal during surgery, preserving bone stock, especially in younger, more active patients who may need future revisions.
- More Natural Load Transfer: They are designed to promote a more natural distribution of stress through the proximal femur, potentially reducing stress shielding and improving proximal bone remodeling.
- Minimally Invasive Surgery: Short stems can facilitate minimally invasive surgical techniques, leading to smaller incisions and faster recovery times.
- Potential for Easier Revision: The preservation of bone stock can make future revisions easier.
- Types of Short Stems:
- Metaphyseal Anchoring: Many short stems are designed for metaphyseal fixation, meaning they are anchored in the metaphyseal region of the femur, which is the area where the bone is thicker.
- Calcar-Guided: Some short stems are designed to be inserted by following the calcar of the femoral neck, allowing for an individualized reconstruction based on the patient’s anatomy.
- Potential Advantages:
- Preservation of bone stock
- More physiological load transfer
- Facilitates minimally invasive surgery
- Potentially easier revision
- May lead to less thigh pain
- Potential Disadvantages:
- Learning curve for surgeons
- Potential risk of malpositioning or fracture
- Potential for secondary mobilization
- Increased incidence of aseptic loosening, implant migration, and periprosthetic fractures has been demonstrated in association with the use of short-stem femoral components
- Considerations for Patient Selection:
- Short stems are often considered for younger, more active patients who are likely to need future revisions.
- They may also be suitable for patients with limited bone stock or those undergoing revision surgery.
- Examples of Short Stem Systems:
- Metha® short stem
- Optimys
- Nanos stem
- A2 stem
- MiniHip stem