Total Hip Resurfacing Arthroplasty: A Patient Information Guide

Total Hip Resurfacing Arthroplasty (THRA), is a surgical option for managing hip arthritis or significant hip damage. Unlike traditional Total Hip Replacement (THR), where the entire hip joint is replaced, hip resurfacing retains more of your natural bone, particularly in the femoral head and neck, while replacing only the joint surfaces. Below, you’ll find an outline of the benefits, risks, and relevant statistics to help you make an informed decision about this procedure.

What is Hip Resurfacing?

In hip resurfacing, the damaged cartilage and bone in the hip joint are removed, and a metal cap is placed over the femoral head. The acetabulum (hip socket) is also lined with a metal cup. This procedure is primarily suited to younger, active patients with good bone quality. However, it is less commonly performed than traditional hip replacement due to specific technical requirements and long-term considerations.

Benefits of Hip Resurfacing vs. Total Hip Replacement

 1. Bone Preservation: Hip resurfacing preserves more of your natural bone, especially in the femoral neck, compared to THR, where the femoral head is fully removed. This bone preservation can make future revision surgeries easier if necessary.

2. Lower Risk of Dislocation: The large femoral head in resurfacing more closely resembles the size of a natural femoral head, which reduces the likelihood of dislocation compared to THR.

3. Potential for High Activity Levels: Patients who undergo resurfacing are often able to maintain a high level of physical activity post-surgery, including running, lifting, and other sports. Notably, Andy Murray had a hip resurfacing and returned to playing professional tennis following this.

4. Revision Options: If revision surgery becomes necessary, resurfacing offers more conservative options due to the bone preservation, making it easier to transition to a full hip replacement if needed. Often a standard, primary hip replacement can be performed in place of a total hip resurfacing, rather than a large revision prosthesis

Risks and Complications

Despite these benefits, hip resurfacing is not suitable for everyone and comes with specific risks:

1. Femoral Neck Fracture: With more bone preserved, there is a risk of fractures in the femoral neck, particularly in patients with weaker or osteoporotic bone. These fractures occur more frequently than in THR and may require conversion to a total hip replacement. Femoral neck fracture are far more common in women than men following hip resurfacing, and as such hip resurfacing arthroplasty is rarely used in women.

 2. Metal Ion Release: Hip resurfacing utilizes metal-on-metal bearings, which can release small amounts of metal ions into the bloodstream. These ions (typically cobalt and chromium) have been associated with potential long-term health concerns, including local tissue reactions, inflammation, and, in rare cases, systemic effects.

 3. Limited Suitability: This procedure is most suitable for younger, active patients under 60 with good bone quality. Patients with small femoral heads or osteoporosis may not be candidates for resurfacing due to increased fracture risks.

 4. Higher Revision Rates: According to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), revision rates for hip resurfacing are generally higher than for THR. The most recent AOANJRR data indicates that while the revision rate for total hip replacements is approximately 5% after 10 years, the revision rate for hip resurfacing can be around 10-12% over the same period, depending on factors such as the patient’s age and activity level.

What’s new in hip resurfacing?

Recently, ceramic on ceramic hip resurfacing have been produced, which may completely eliminate many of the risks of traditional hip resurfacing, most notably the metal ions. These prosthesis are currently being used widely overseas and are in trial phase in Australia.

Revision Statistics from AOANJRR

Based on data from the AOANJRR, younger patients who undergo hip resurfacing, especially males under 55, tend to experience relatively lower revision rates than older or female patients. However, patients should understand that, across all demographics, revision rates for resurfacing remain higher than for THR.

Conclusion: Is Hip Resurfacing Right for You?

Hip resurfacing can be an excellent choice for younger, active patients who wish to maintain higher activity levels and preserve more of their natural bone. However, it’s essential to weigh these benefits against the potential risks and the likelihood of requiring revision surgery in the future.