Minimally Invasive Total Hip Arthroplasty

TSUJI ORTHOPAEDIC INSTITUTE PAINFUL LESION

MINIMALLY INVASIVE TOTAL HIP ARTHROPLASTY

In more and more hospitals, minimally invasive total hip arthroplasty (replacement) is being introduced using the mini-incisions as long as two to four inches. This can be performed both with the anterior approach and with the posterior approach to the hip joint.

My opinion is that with the posterior approach, we may have to dissect the soft tissue fairy much inside however hard we may try to make the external skin incision smaller, because the acetabular socket is facing anteriorly. If you still want a minimal dissection deep in side as well, you might need a curved acetabular reamer especially designed for minimally invasive total hip arthroplasty or computer navigation system. And the results may not be reproducible. You may sometimes be satisfied with your results or may not be satisfied with your results at other times when you are reaming blindly or relying upon the inaccurate computer navigation system.

What we want is 100% success rate at the time of surgery. I think this is one of the reasons why some surgeons stay conservative who prefer perfection at all times. Compared with posterior approach, anterior approach offers us a better view of the whole acetabular socket with smaller deep soft tissue release as well as minimal skin incision on the surface. Accuracy to the point of 1mm is met when we are reaming the acetabulum under direct visualization, which is especially necessary for patients with osteoarthritis secondary to developmental dysplasia of hip (DDH). Blind reaming is accepted, although not ideal, in patients with primary osteoarthritis, but reaming the acetabulum under direct visualization is essential in patients with hip dysplasia. Anterior approach also has the advantage of lower dislocation rate even when the patient is squatting as in bathroom.

My approach is somewhat different from the one in some other famous websites for MITHA which use posterior approach and also different from the Zimmer MIS Mini-Incision method (although I am one of the very good customers of Zimmer, Inc.). I am going to show the actual photos of the minimally invasive total hip arthroplasty operation below. The photos in the center and the photos on the left shows the case which I had operated with the anterior approach in 2003 before the approval of ceramic-on-ceramic bearing by FDA and before the Zimmer, Inc. had rented us the surgical instruments for minimally invasive total hip arthroplasty. (Now at the moment, I'm very happy with their handy instruments.) The photos on the right are added later showing the ceramic-on-ceramic articulation hip arthroplasty. I think this is a nice approach and prevailing in other hospitals as well and hope to be used in more and more hospitals because we can obtain both direct visualization of the hip socket for acetabular component fixation and direct visualization of the femoral canal for stem implantation.

First, three-inch straight skin incision is made laterally to the hip joint.

Femoral head and neck is exposed anteriorly.

Femoral neck cut is made at an adequate level and femoral head is removed from this small incision like this.

This is the view of the acetabulum through the mini-incision.

The acetabular shell is placed in a correct position.

Polyethylene liner is fixed over this shell in this patient on the left photo, and ceramic acetabular component is placed in another patient on the right photo.

Femoral stem and cobalt-chrome head is placed into the femur in this patient on the left photo, and ceramic head is placed in another patient on the right photo.

Femoral head is reduced into the acetabular cup in this patient on the left photo, and ceramic-on-ceramic bearing articulation in another patient on the right photo.

The wound is closed subcutaneously with an absorbable suture.

The preoperative x-ray of this patient on the left and the postoperative x-ray of this patient on the right.

Photograph of the 6cm-wound mini-incision total hip arthroplasty ( minimally invasive total hip arthroplasty ) of another patient six months post-operatively.