Big Head Technology
Demands of the modern patient have changed. They wish to be informed and desire cutting edge technology rather than accepting conventional treatment.
The young patient with a higher activity profile requires a stable hip joint without restriction and is therefore well suited to a big head metal on metal articular bearing surface, as shown in the x–ray below.
This is the choice of implant for fracture neck of femur and avascular necrosis as a consequence of a Resurfacing Hip Replacement (RHR) procedure. The size of the femoral head is tailored to the patient's socket size.
With big femoral heads, the choice is either a metal on metal, ceramic on ceramic or ceramic on metal bearing surface. The large head simulates the patient’s own femoral head and so feels natural in function, while also increasing stability which in turn reduces the risk of dislocation.
These new big head bearing surfaces are exceptionally smooth and have a low coefficient of friction. The technological advances in bearing materials have resulted in reduced wear and this should, therefore, give an increased longevity of the hip joint.
This is in contrast to the use of conventional polyethylene which is restricted to socket/liners with small heads to reduce the frictional torque and thus reduce polyethylene debris. New crossed polyethylene may reduce wear in patients with lower activity demands. However, some manufacturers have used crossed linked polyethylene with larger heads. This may be possible with vitamin E polyethylene used as a cemented cup or as a liner within the acetabular shell.
The aim is for longevity of the artificial hip joint with unrestricted activity — hip joint stability and the elimination of dislocation.
Appointments
To make an appointment e–mail Sue Misir, secretary to Mr Evert Smith, or telephone:
- 0117 907 4228 (private)
- 0117 323 5194 (NHS)
For an NHS appointment your GP will need to refer you. How?
Evert Smith is an Orthopaedic Surgeon in whom I have absolute faith and confidence.
Bob Gibbons, 2007.