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Dr. Todd Swanson
Minimally Invasive Techniques/ Squeaking Ceramic Hips
Sat Oct 23, 2010 1:05pm

Minimally Invasive Hip Replacement Surgical Techniques

The anterior approach for total hip replacement has been around for many years, initially termed the Smith-Peterson approach or the Hueter approach. Recently, with the advent of a special orthopedic table designed and popularized by Joel Matta in California, it has received a lot of media attention. The approach utilizes natural tissue planes to approach the hip from the front rather from the side or back. The fact that the approach “cuts no muscle” has led to many (unproven) claims of quicker recoveries and improved function. Additionally, any approach that leaves the posterior hip capsule and external rotator muscles intact is likely to have a lower posterior dislocation rate than the posterior approach which requires detachment of some of the external rotators and part of the posterior capsule.

Unfortunately, as with many new techniques or technologies, they sometimes are too good to be true. Additionally, they are often hyped to market a surgeon’s practice in spite of little or no data supporting the claims. Having just completed writing a book chapter on the posterior MIS approach to the hip, I have reviewed all of the literature on all of the MIS approaches and can say that the anterior approach has no significant proven advantages over the posterior approach. A retrospective study comparing the 2 techniques suggests that patients may function at a slightly higher level at 3 weeks with the anterior approach, but the downside is that there is more blood loss, a higher risk of transfusion, and the hips can still dislocate (often anteriorly rather than posteriorly). A cadaveric comparison of muscle damage caused by each of the 2 approaches showed that the anterior approach does damage muscle around the hip in spite of utilizing natural tissue planes—just different muscles than those affected by the posterior approach. Even more interesting is that in ˝ of the anterior cases studied, the posterior capsule and external rotators had been transected, even though the hip was approached from the front!

So the jury is still out regarding any significant functional differences between the anterior and posterior approaches. The dislocation rate with a posterior approach is approaching 0 due to better implants (larger heads and high offset stems) and surgical technique (repairing the posterior capsule, such as with the Capsular Noose Technique), so there really is no advantage using the anterior approach with respect to dislocation rates any more. I have heard that at least 1 prospective randomized study is underway, and I with another surgeon who uses the anterior approach have received IRB approval to do our own prospective study comparing the 2 approaches. But for the time being, I think all that can be said is that both approaches work well and can give good results in the hands of surgeons trained and experienced in the techniques. As always, don’t believe everything you hear.

Squeaking Ceramic Hips

While the wear rate with ceramic-on-ceramic total hip replacements is negligible and other problems (including fracture) extremely rare with the use of well-designed components and accurate surgical technique, squeaking in total hip replacements has recently become an issue. Squeaking in total hip replacements is thought to be caused by roughening of the ceramic surface of one or both components, or the presence of 3rd body debris in the space between the ball and socket.

Any impingement between the neck of the femoral component and the ceramic liner of the socket can generate particles of ceramic and/or metal that may lead to squeaking. Partial shucking of the head in and out of the socket may also cause damage to the ceramic surfaces stripe wear. Avoiding these problems is highly dependent on accurately positioning the acetabular and femoral components.
Recently, it has been noted by several authors, including myself, that a particular design of ceramic liner (where the ceramic is protected from chipping by a metal ring which extends past the ceramic) used with a specific femoral component manufactured by the same company has lead to an extremely high risk of squeaking. The squeaking likely occurs due to impingement of the metal femoral neck against the protective metal ring, generating metal debris which enters the interface between the ball and socket and causes a vibration that we hear as a squeak. In my practice, the incidence of significant squeaking in designs without the protective ring is less than 1/2% while the incidence of squeaking in a small group of ceramic hips with this protective ring is >10%, a 20-fold increase. Therefore, many surgeons, including myself, have quit using this acetabular component design.

Ceramic hips require very precise placement of the components to prevent impingement between the femoral and acetabular components. However, if done well, a ceramic hip should wear extremely well without chipping, breakage, or squeaking, and also without the theoretical risks that metal-on-metal hips carry.

Because implant positioning is absolutely critical to the success of a ceramic-on-ceramic total hip replacement, be sure to ask your surgeon how much experience he has with ceramic-on-ceramic hip replacements. Done well, these hips may last your lifetime, even if you are young and active.

Dr. Todd Swanson

  • Hip Optionstony r, Sat Oct 23 1:02pm
    I am confused about two things. One, how do you compare the benefit of a less invasion posterior hip approach versus an anterior approach. Two, if a patient decides to get a ceramic-on-ceramic hip,... more
    • Minimally Invasive Techniques/ Squeaking Ceramic Hips — Dr. Todd Swanson, Sat Oct 23 1:05pm
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