Hip joint resurfacing is usually reserved for active, younger adults (40s and 50s). And the results have been very successful. So what’s stopping surgeons from using this technique with older adults (65 and older)?
Hip joint resurfacing is a type of hip replacement that removes the arthritic surface of the joint but takes far less bone than the traditional total hip replacement. During the procedure, the femoral head is shaved and shaped so that a metal cap can be fit snugly over top of the bone. The cap is held in place with a small peg that fits down into the bone. The acetabulum (hip socket) may remain unchanged. But more often it is replaced with a thin, metal cup. The acetabular component is pressed into place in the socket.
Current thinking on this subject is that older patients don’t have the bone strength and density to hold up under joint resurfacing. The danger of a femoral neck fracture is too high. And older adults who are less active don’t need resurfacing. They can get a total joint replacement that will last them the rest of their lives.
But there really isn’t much evidence to support any of these arguments. This is one of the first studies to compare results of hip resurfacing between two age groups. The first group was 60 years old or older. The second (larger) group was younger than 60 (between 18 and 59 years old).
Patients in both groups were operated on by the same surgeon during the same time period. They all received the same type of metal-on-metal resurfacing implant. Both the femoral and acetabular components were resurfaced. Results were measured using clinical outcomes such as pain and function, as well as comparing X-rays and complications.
The results were very similar for both groups. Recovery time was the same regardless of age. X-rays showed equal angles for the cup placement and femoral head and neck. These angles indicate accurate placement of the components needed for good results.
And the number of problems that occurred after the surgeries was also very similar between the two groups. When it was necessary to convert from resurfacing to a total hip replacement, there were more younger patients who needed the revision surgery.
The reasons for failure of the resurfacing was different between the two groups. Hip fracture or shifting of the acetabular cup was more common in older adults. A condition called heterotopic ossification (HO) occurred in the younger group. HO describes a problem in which bone forms outside the joint in the soft tissues.
The results of this study support the use of joint resurfacing for older adults. This is consistent with the few other studies that have also been published. Failure rates and poor function of hip joint resurfacing is the same in older adults compared with younger adults. Quality of bone and deformity of the femoral head and neck are the major risk factors for poor outcomes. And at least from this study, these are not necessarily linked with age.
Adults are living longer and staying more active suggesting the need for treatment alternatives such as joint resurfacing. Age alone should not be the sole determining factor of whether or not someone could benefit from this procedure. The authors do point out that their results only extend for three years, so more time is needed to judge the final results.