By Dr. Bose Thursday August 10, 2006
There are two ways to look at approaches to hip resurfacing or any hip arthroplasty. One is to view it with the amount of muscle damage done. The other is to view it in respect to the blood supply or the vascularity. The post approach is traditionally known as the muscle sparing approach and the anterior and anterolateral approaches are the muscle compromising approaches. These approaches are known as Hardinge approach or London hospital approach. There are many more modifications of this with slight variations but essentially they are the same and they disturb muscles to varying extents. The muscle here refers to the Abductor group or the muscles which lift your leg sideways and is the most important muscle of the hip. The post approach spares this completely. Interestingly there is now an anterior approach which is getting to be very popular for mini -THR and this is known as the mini Watson Jones approach or the micro hip approach. This does not disturb the abductor though it a ant. approach. However resurfacing cannot be done through this approach. Even when one does a THR the head has to be sawed off in place and then delivered out separately. Or in other words the hip cannot be ‘dislocated’ through this approach which precludes hip resurfacing. However some muscle have to be cut in any approach to get access to the hip and in the post approach, one cuts the short ext rotators which are flimsy , small muscles in the back of the hip. These are stitched back. These muscles are relatively unimportant. It is largely accepted that the post approach is more conducive to early and complete return of function as it is muscle sparing. The ant approaches which disturb the gluteus medius will result in slower and incomplete return of function depending on the amount of muscle disturbed and the intactness of the muscle repair over long term. The younger and the more active the patient , the more would be the perceptible difference between the ant and post. approaches as regards function. Thus an elderly patient having a THR will appear to have the same result with either approach whereas a young patient having a resurfacing will have an obvious difference.