Hemiarthroplasty, also known as partial hip replacement, is a surgical procedure that involves replacing the "ball" part of the hip joint (the femoral head) with an artificial implant while preserving the natural socket (acetabulum) of the hip joint. This procedure is typically used to treat conditions where the femoral head is damaged or deteriorated, such as fractures of the femoral neck or avascular necrosis. Here's an overview of how hemiarthroplasty is performed:

• Anesthesia: The patient is placed under general or regional anesthesia to ensure they are pain-free during the procedure.
• Incision: The surgeon makes an incision on the side of the hip to access the joint.
• Removal of damaged tissue: Any damaged or deteriorated femoral head is carefully removed.
• Preparation of the femur: The upper end of the femur (thigh bone) is prepared to receive the prosthetic femoral component. This may involve reshaping the bone to ensure a proper fit for the implant.
• Implantation of the prosthetic femoral head: A prosthetic femoral head component, typically made of metal or ceramic, is securely attached to a stem. The stem is inserted into the prepared femur, and the prosthetic femoral head replaces the damaged or diseased femoral head.
• Closure: The surgeon closes the incision with sutures or staples.
• Recovery: Following surgery, patients undergo a period of rehabilitation and physical therapy. This is essential for regaining hip joint mobility and strength. The recovery time can vary depending on the individual and the specific condition being treated.

Hemiarthroplasty is often used for elderly patients with displaced hip fractures or for individuals with avascular necrosis of the femoral head. By replacing the damaged femoral head, pain is often relieved, and hip joint function can be partially restored, allowing for improved mobility and quality of life.

It's important to note that hemiarthroplasty only addresses issues with the femoral head and not the acetabulum (the socket). In cases where both the femoral head and the acetabulum are affected by arthritis or other conditions, a total hip replacement (total hip arthroplasty) may be considered. In total hip replacement, both the femoral head and the acetabulum are replaced with prosthetic components.

As with any surgical procedure, hemiarthroplasty carries risks and potential complications, such as infection, implant loosening, or nerve injury. Patients should have a thorough discussion with their orthopedic surgeon to understand the benefits, risks, and expected outcomes of the procedure before making a decision.