Hemiarthroplasty (Hemi Replacement of the Hip): A surgical procedure where only one half of the hip joint is replaced. Specifically, the femoral head (the ball part of the ball-and-socket joint) is replaced with a prosthesis, while the acetabulum (the socket) is left intact. This procedure is commonly performed for certain types of hip fractures or severe arthritis.
Indications
- Femoral neck fractures (often in elderly patients with osteoporosis)
- Severe arthritis or degeneration limited to the femoral head
- Avascular necrosis of the femoral head
- Failed internal fixation of a hip fracture
Preoperative Preparation
Patient Evaluation:
- Comprehensive medical history and physical examination.
- Imaging studies: X-rays, MRI, or CT scans to assess the extent of damage.
- Blood tests and other investigations to evaluate the patient’s fitness for surgery.
Anesthesia:
- General anesthesia or spinal/epidural anesthesia, depending on the patient’s health and preference.
Patient Positioning:
- The patient is placed in the supine or lateral decubitus position on the operating table.
Surgical Procedure
- Incision: A surgical incision is made on the lateral or posterior aspect of the hip. The choice of approach depends on the surgeon’s preference and the patient’s anatomy.
- Exposure: Muscles and soft tissues are carefully retracted to expose the hip joint.
The hip is dislocated to access the femoral head. - Femoral Head Removal: The femoral head is removed using surgical instruments, and the femoral canal is prepared for the prosthesis.
- Surgeons may use a variety of tools, including reamers and broaches, to shape the canal to fit the prosthesis snugly.
Prosthesis Insertion:
- The chosen prosthesis is inserted into the femoral canal.
Prostheses can be cemented or uncemented:
- Cemented: Bone cement (polymethyl methacrylate) is used to fix the prosthesis in place.
- Uncemented: The prosthesis has a porous surface that allows bone to grow into it, securing it over time.
Reduction and Closure:
- The hip is reduced back into its normal position.
- Muscles and soft tissues are reattached and sutured.
- The incision is closed in layers, and a sterile dressing is applied.
Postoperative Care
Immediate Postoperative Care:
- Monitoring vital signs and managing pain with medications.
- Early mobilization with the help of physical therapists, typically starting with weight-bearing as tolerated.
Physical Therapy:
- A tailored rehabilitation program to restore strength, range of motion, and functional mobility.
- Use of assistive devices like walkers or crutches as needed.
Wound Care:
- Regular inspection and care of the surgical wound to prevent infection.
- Removal of sutures or staples typically occurs around 10-14 days post-surgery.
Follow-Up:
- Regular follow-up visits to monitor healing, prosthesis position, and function.
- Imaging studies as needed to ensure proper placement and integration of the prosthesis.
Potential Complications
- Infection
- Blood clots (deep vein thrombosis or pulmonary embolism)
- Dislocation of the prosthesis
- Prosthesis loosening or failure
- Nerve or blood vessel injury
- Leg length discrepancy
Hemiarthroplasty is a commonly performed procedure, especially in elderly patients with hip fractures. The surgery aims to relieve pain, restore function, and allow early mobilization. Success depends on careful preoperative assessment, meticulous surgical technique, and comprehensive postoperative care, including physical therapy and regular follow-up. By addressing these factors, patients can achieve significant pain relief and improved quality of life.
