Resurfacing Hip Replacement or Resurfacing Arthroplasty (RA) replaces the surface of the femoral head (the ball). This is the top part of the bone in the upper leg (the femur) which is subject to wear caused by arthritis. In RA, only the surface of the femoral head is reshaped and resurfaced. The femoral component is made of metal.
RA leaves more of the bone in place and does not remove the femur neck shaft as with total hip replacements (THR). For this reason, it was popular for relatively young patients with a high activity profile as compared with others of similar age. As a less invasive procedure it was often used before a conventional THR in younger patients. Patients with neuromuscular disorders, those on immunosuppressant therapy, or those with a previous history of sepsis in the hip region may benefit from RA. The shape of the hip joint allows for inherent constraints and stability, as the radius of curvature of the acetabulum matches the articular surface of the femoral head. Therefore, resurfacing the articular surfaces makes fundamental sense, in selected patients.
Although RA is no longer a popular choice, the concept remains an attractive option for the high activity profile male (the young male) because it is a bone conserving procedure. This is true of the famous tennis player, Andy Murray, who informed the world that he had undergone a RA at a young age. So, RA utilising a successful brand, remains an option in carefully selected patients.
RA commonly used metal on metal (MoM) implants as the properties of MoM offered perceived benefits of improved range of motion, reduced risk of dislocation and low wear. It is now known that some MoM RA and THR implants suffer unacceptable, higher than expected failure rates and so the use of MoM stemmed, and resurfacing implants is now ‘extremely rare’(National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) 15th Annual Report 2018, page 101). It should be noted that not all MoM hip device brands succumbed to early failure. In 2017, the Birmingham Hip Resurfacing Device was given an Orthopaedic Data Evaluation Panel (ODEP) 10A* rating (the best possible rating) when used in males only, using head sizes 48-62mm only. MoM devices were approved for use all over the world, including by The Federal Drug Authority (USA).
Since NJR records began in 2003 to December 2015, there have been a total of 40,154 MoM RA, representing 4% of the total number of hip replacement operations performed (NJR 15th Annual Report, Page 39). The best performing RA brand has a failure rate of 7.95% (95% CI 7.56-8.37) at 10 years (NJR 15th Annual Report, page 101) as opposed to 14.76% at 14 years for RA brands overall (NJR 15th Annual Report, Page 24). So, there remains a place for RA in young active males when utilising a specific head size.
Access to the hip joint takes advantage of the muscular planes surrounding the joint. There are four approaches.
- Anterior (front) Approach
- The anterior approach has been revitalised for minimally invasive surgery (MIS).
- Two Lateral (side) Approaches
- The anterolateral approach is the most commonly used approach for total hip replacements.
- The direct lateral approach exposes the hip joint by detaching the upper end of the thigh bone (the greater trochanter).
- Posterior (rear) Approach
- The posterior approach is the second most common approach when performing a THR and is commonly used for minimally invasive surgery (MIS).
Advantages of RA
- Preservation of the femoral head/neck
- Low-wear rate in some brands
- Maintenance of biomechanics of the hip joint
- Technically demanding operation
- Fracture of neck of femur
- Avascular necrosis of the femoral head
- Leg length discrepancy
- Loosening and lysis
- Dissemination and elevation of metal ions
- Fluid collections
- Cystic and/or solid masses - 'pseudotumours'
- Inflammatory reaction and tissue necrosis
- Potential carcinogenesis
The relative contraindications for RA are related to abnormalities of the bony architecture of the pelvis and femur, as these cannot be corrected and/or the device cannot be correctly and accurately seated. It is more appropriate to treat elderly osteoporosis patients with a conventional THR.
Femoral neck fractures can occur in about 1.5% of patients and tend to happen in the early period following the procedure. Like avascular necrosis, femoral neck fractures are a unique complication of RA. With avascular necrosis, there is subsequent progressive collapse of the femoral head. Both conditions require conversion to a THR to remove the MoM bearing surface.
When there is loss of bone in the proximal femur and problems of leg length discrepancy, then an alternative bearing combination should be selected, for example a ceramic on ceramic bearing.
- Patients who have a high activity profile and who have minimal loss of bone architecture
- Patients who have loss of bone architecture, poor bone quality, focal bone defects, and an abnormal anatomy of the hip region
- Small sized femoral heads – these patients are, more often than not, female
- Renal Insufficiency
- Dislocation: When the ball of the femoral component is dislocated from the acetabular cup. This is less common with RHR due to innovations in big head technology
- Infection: A bacterial invasion of the hip joint
- A lengthened or shortened limb http://evertsmith.com/treatment/hip-complications/#leg-length
- Fracture of femur: A crack or break of thigh bone
- Femoral neck fracture: A crack or break in the femoral neck
- Avascular necrosis of the femoral head: Death of the bone in the head
- Vascular injuries: Penetration or incision of an artery or vein
- Non union of the greater trochanter: Following an osteotomy, the bone fails to unite
- Heterotopic ossification: New bone formation where bone is not normally present
- Stem breakage: A crack or fracture of the femoral stem
- Loosening: Loosening of the hip joint prostheses
- Wear: Erosion of the surface where two materials are in contact with one another
- Pseudomembranous colitis: A bowel problem related to antibiotic treatment
- Anaesthetic complication: (Rare) Complications may result from a general and/or spinal or epidural anaesthetic
- Death: Rare
On the first day, most patients will have had their intravenous drip removed. A physiotherapist will see you after surgery and from then on begin muscle strengthening and stretching exercises. You will be taught the safe way to get in and out of bed. The physiotherapist will teach you how to use a support, and you will be encouraged to take exercise on a regular basis. By the time of discharge, around 3 to 7 days, you will be able to perform all activities unassisted. You will be able to return home in a car. It is best to have help at home in the early stages.
Walking is good for your RA and is excellent exercise. Non-impact sports are advisable, such as swimming, cycling and golf. Your functional ability will improve rapidly week by week until you are able to drive a car at 6 weeks and return to other prior activities.