The term “osteotomy” refers to division of bone.  It is something like a controlled fracture.  The biology of bone is marvellous.  If the controlled fracture or osteotomy is performed satisfactorily, and post-operative management is exemplary, the osteotomy will eventually heal.  It means, however, that the direction of weight bearing forces can be altered by changing the direction in which the bone points or faces.

These osteotomies can be used on the pelvic side of the joint or on the thigh bone or femoral side of the joint.  Sometimes osteotomies can be performed on both sides, either separately or simultaneously. 

The goal of these osteotomies is to improve the biomechanics of the hip joint itself. 

Assume, for example, that the socket is too shallow, is too large or is facing in the wrong direction.  The weight bearing forces transmitted to the ball are abnormal in magnitude, abnormal in direction, and will tend to excessively wear one small part of the ball in preference to others.  This is how osteoarthritis can start and progress.  By changing the size, the direction or the inclination of the socket, those forces can be very dramatically reduced.  Successful osteotomies around the socket can reduce the symptoms experienced by a patient, can retard the rate at which any form of arthritis process may develop, and give rise to an extremely satisfactory outcome in a well-chosen subject. 

Similar concepts apply on the thigh bone or femoral side of the joint.  Load bearing forces can be redirected, can be changed in magnitude, and can be used as friends rather than foes. 

Whilst osteotomies around the hip joint are performed far less commonly than say thirty or forty years ago, they still have a very important role to play.  Surgeons who specialise in hip surgery specifically are usually well skilled in this particular area.