Adult patients with severe hip problems present new challenges for the orthopedic surgeon. This study presents the second report on a group of 20 patients. Each one had severe developmental dysplasia or total hip dislocation.

All received a porous-coated shell called the acetabular component. This shell or socket covers the head of the femur and prevents it from slipping out or dislocating. A porous surface is rough (not smooth). This feature makes it possible for bone to grow into the implant, helping to lock it in place.

In the first study, these patients were followed for five to eight years. In this second report, follow-up continued for another nine years. X-rays were taken to look for wear, movement of the implant, or changes in the bone. The amount of wear of the plastic liner was also measured.

The authors report 19 patients still had the same acetabular shell in place after 16 years. This in itself is an excellent long-term outcome. Overall results were rated from poor to fair to good to excellent with a fairly equal number in each category. Two hips were revised because of implant loosening or liner wear.

This study supports the use of cementless sockets in patients with developmental hip dysplasia or total dislocation for better wear and longevity. Results do deteriorate over time but the average implant lasted 15 years with good to excellent results reported.

Reference:

Brett J. Hampton, MD, and William H. Harris, MD. Primary Cementless Acetabular Components in Hips with Severe Developmental Dysplasia or Total Dislocation. In The Journal of Bone and Joint Surgery. July 2006. Vol. 88. No. 7. Pp. 1549-1552.'