Complex Anterior Total Hip Replacement


I initially discussed the direct anterior approach (DAA) for total hip replacement in an earlier blog. Demand has increased with more patients requesting the anterior approach for hip replacement due to studies demonstrating decreased pain, quicker recovery and better quality of life outcome measures. However the approach must be taken with caution as there is a high learning curve with increased complications for those not familiar with the approach. Early in the learning curve cases must be carefully selected as straight forward and complex cases (acetabular protrusion, coxa vara, dysplasia, revisions) should be avoided. Complex cases can be performed through the DAA with proper training and experience. I will review two such cases below.

(Case 1) Acetabular Protrusio

Fig 1

Acetabular protrusio is a condition where the femoal head has migrated through or past the floor of the acetabulum (ball has worn completely through the socket floor). In figure 1 these are depicted as the head (ball) by the purple line and the ilioischial line and teardrop (floor of the socket) with a greay line. This makes the overall approach much more difficult as the hip does not move much, the cut through the neck is difficult and exposure of the femur (thigh bone) is much harder. In addition often the floor needs to be filled in with bone graft and the socket needs to be prepared very carefully to avoid the socket migrating into the pelvis!

But with advanced experience in the DAA all of these issues can be overcome and a stable, well functioning hip replacement (or in this case two) can be placed in a straight forward fashion with a few additional steps and precautions.  

Fig 2


(Case 2) Acetabular Dysplasia/Defect

Acetabular dysplasis is a condition where the acetabulum (socket) does not form correctly. This can be congenital or more often acquired.  If identified during infancy this can be managed with bracing or surgery if in a toddler. If subtle, dysplasia may be missed until after skeletal development. It does not always translate into hip issues in the future or progressive arthritis. But a great percentage of young patients with hip replacements before 50 years old have either hip dysplasia or femoroacetabular impingement (briefly discussed in "Your Hips Have a Reason to Hurt"). 

Once into adulthood dysplasia can progress to arthritis with varying degrees of complexity. Sometimes the dysplasia is so bad that the femoral head (ball) will come partially (sublux) or completely out (dislocate) of the acetabulum (socket). 

Fig 3 Acetabulum (socket) in purple; Femoral head (ball) in yellow

You can see in the image (Fig 3) above that the right hip has subluxed out of the socket with flattening of the head and has produced a defect on the side of the acetabulum.  This is a case where the new socket or hip replacement may not be adequately covered with bone and additional bone or a metal wedge (augment) will need to be placed to cover the new socket to prevent it from coming out of the pelvis. To place augments increased exposure of the bone is needed along with additional soft tissue releases. As well as careful reaming of the socket. All of these issues increase the complexity of this case but can again be managed from with the DAA.

Fig 4


The direct anterior approach (DAA) for total hip replacement is in my opinion superior to other hip approaches. It allows for real time fluroscopy for accurate cup placement, is a muscle sparing approach with some advantages in regards to recovery. However the learning curve is steep with many surgeons avoiding complex cases of deformity, obesity, and revisions due to this complexity. But with advanced experience in the DAA all of these issues can be overcome and a stable, well functioning hip replacement (or in this case two) can be placed in a straight forward fashion with a few additional steps and precautions. 

As a DAA patient you will be up and walking the day of surgery and most patients go home the next day. If deemed a candidate, some patients can have their hip replacement performed in an outpatient setting and go home the same day as their hip replacement.  

Call to schedule an appointment today. Whether you need a hip replacement or just have hip pain! We also offer same day in office ultrasound guided hip joint injections!



Dr. Dustin Woyski Orthopedic Surgeon and Hip Specialist

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