This includes the round ball at the top of the femur (thighbone) with a stem that fits down into the femur. The acetabulum (hip socket) is not replaced. THR removes and replaces both sides of the joint (femoral head and acetabulum).
Patients with a displaced fracture of the femoral neck were divided into two groups. One group had a hemiarthroplasty. The other group had the THR. Short-term results were measured after three years.
Walking distance and function were the main outcomes compared. X-rays were also taken and viewed for any erosion of the bone and narrowing of the joint space. Results showed that the THR group walked further and had better function than the hemiarthroplasty group.
The authors also reported that both groups had decreased function after surgery compared to before the hip fracture. Walking distance was especially decreased in the hemiarthroplasty group.
Painful acetabular erosion was the most likely reason for this change in walking ability in the hemiarthroplasty group. Erosion appears to be linked with higher activity levels in younger patients.
The findings of this study suggest THR is better than hemiarthroplasty for active, healthy adults. Further study is needed to make the same treatment comparison for less active, mentally impaired older adults.