Why is Hip Resurfacing better than Total Hip Replacement?
Dr. De Smet
Theoretic advantages are less bone destruction, less bone resection, normal femoral loading, avoidance of stress shielding, maximum proprioceptive feedback, and restoration of normal anatomy. In addition, reduced risk of dislocation, less leg inequality problems, and easier revision should convince surgeons to favor metal-on-metal resurfacing.
A resurfacing is suitable for the treatment of a hip with severe arthritis when the femoral head bone quality is good. It is used more often in young and active patients than older and less active patients because conventional replacements do not last long in young and active patients. Further, a younger patient is more likely to need a revision of an artificial hip at some stage later in life, and it is easier to successfully revise a BHR.
The fundamental difference between a BHR and a conventional total hip replacement (THR) is in the femoral (thigh) side. A THR has a long stem inserted into the canal in the thigh bone. Hence the natural femoral head and part of the neck are removed and weight is transmitted through the stem directly into the upper third of the thigh bone. In a resurfacing, the aim is to preserve most of the femoral head and neck. The resurfacing femoral component therefore has a thin (3 to 4 mm) hollow ball surface that directly transmits weight to the femoral head bone underneath it and a very small stem that is not designed to transmit weight. The socket component can be similar in both the THR and a BHR.
•The ball used during surgery is similar to the natural one, which confers biomechanical advantages to the hip.
•Hardly any chance of dislocation.
•Improved durability, since the prosthesis does not wear out easily.
•Allows improved functions and quick recovery.
•Patient can sit, squat and even can participate in sports.
•Allows normal range of hip movements.
•Does not change length of the leg.
•Duplicates or restores normal structure of hip joint.
•Suitable for Younger Patients
•Femur Bone not removed
•Articulation is metal with metal
•’Everlasting’ – based on 35 year history in
Birmingham of Metal on Metal Articulation
•Activity restriction not required after surgery as there is hardly any risk of dislocation (can sit on floor ,squat, use Indian toilet ,etc)
•Sport and High demand activities encouraged as usage is not related to life of resurfacing implant
•Revision surgery not Required for younger patients
The Birmingham Hip Resurfacing is the answer to younger patients with severe hip pain due to arthritis. These patients are too young for a total hip replacement because of the severe limitations after the surgery.
Unlike traditional hip replacement surgery, resurfacing does not remove as much of your leg bone. Instead, the process simply machines away the rough damaged surface of the hip joint bones and replaces them with more durable high carbide cobalt chrome.
For younger patients concerned with the potential of multiple revision surgeries over their lifetimes, saving natural bone is especially important. But hip bone conservation is good for older patients as well if their bones are strong enough to accept the implant.
The BIRMINGHAM HIP RESURFACING System has been shown to actually enhance bone strength around your hip. (Kishida, Sugano 2004 JBJS) The more you walk on your resurfaced hip, the stronger it gets.
The BHR is not "experimental surgery". Although its use in the US has been approved by the FDA only last year, there have been over 60,000 BHR hips implanted worldwide since 1996. At 10 years follow up, 98% of implants have survived. A 1,626-hip study found that 99.5% of patients responded they were “Pleased” or “Extremely pleased” with the results of their Birmingham Hip Resurfacing surgery.
Hip resurfacing is a bone conserving alternative to conventional total hip replacement ( THR). Unlike THR, hip resurfacing does not involve the removal of the femoral head and neck nor removal of bone from the femur. Rather, the head, neck and femur bone is preserved in an effort to facilitate future surgery should it be necessary and to enable the patient to take advantage of newer technology or treatments in the future. Refer to the interactive animations on this website for detailed descriptions of both hip resurfacing and total hip replacement.
The current generation of hip resurfacing devices utilize a metal-metal bearing rather than the metal-polyethylene bearings that were utilized in the 1970’s and 1980’s. Metal-metal bearings have demonstrated a much higher level of wear resistance as well as reduced bone loss and inflammatory tissue reaction about the hip joint as compared to metal-polyethylene bearings.
Hip resurfacing is anatomically and biomechanically more similar to the natural hip joint resulting in increased stability, flexibility and range of motion. Further, dislocation risk is virtually eliminated. Higher activity levels are typically achieved with less risk than with a THR should a revision ever be necessary. These benefits are realized because the head diameter that results from resurfacing is very similar to the patient’s normal head diameter and these larger head sizes are typically much larger than the femoral balls utilized in conventional THR. It should be noted, however, that THR with larger femoral balls is now available and these devices can also result in a high degree of stability with minimized risk of dislocation.
Advantages of Hip Resurfacing Replacement
While every orthopaedic treatment has both benefits and risks, there are some advantages unique to surface replacement.
The preservation of bone has several potential advantages. The first is that more bone is retained in the femur, should another hip replacement become necessary. Over time, any hip replacement may loosen or show signs of wear. In a young, active population, there is a high likelihood that more than one hip replacement operation may be necessary over the lifetime of the patient. The more bone that remains during a revision (re-do) hip operation, the greater the chances of success.
The second advantage to a surface replacement is that the preservation of bone allows for a much larger ball size. This allows for greater stability of the hip joint and a lower risk of dislocation. The dislocation rate after surface replacement of the hip has been shown in some studies to be about 10 times lower than for a traditional hip replacement.
Hip joint resurfacing maintains the natural size of the femoral head and neck. Proprioceptive feedback from the preserved metaphyseal bone and joint capsule continue and there is normal biomechanical function.8,26 The resurfaced hip is stable and capable of an excellent range of motion. With a limited amount of implanted material, infection if it occurs, can be dealt with easily. Because the femur is not decapitated, hip resurfacing is less invasive (rather than small incision) surgery. There is less pain and blood loss from resurfacing compared to conventional replacement with an earlier return of function. Unique disadvantages are the possibility of a femoral neck fracture or a collapsed femoral head from osteonecrosis.
From NY Times Article by Dr. Pritchett
There has been good literature and a good track record with favorable 10-year results. While it is a difficult surgery and the learning curve is steep, (the procedure) will hold up on a long-term basis and can be a permanent solution for eligible patients.
Think about the hip joint as a ball and socket. Total hip replacement is like removing the ball and replacing it with a metal ball, whereas resurfacing is capping the ball.
Two years after the surgery, he finds resurfacing patients do have slightly more range of motion in their movements than his older patients who’ve undergone total hip replacement.
Advantages of a hip resurfacing in my hands are:
(1) more range-of-motion
(2) less risk of dislocation
(3) more normal "feeling"
(4) leaves options open for later conversion to standard THR
(5) Easy revision if necessary
(6) useful for certain deformities
(7) preservation of femoral bone stock