A hip joint replacement surgery can be preformed through many different approaches with excellent results. Two recent advances in hip replacement approaches include the SuperPath approach and the direct anterior approach. Dr. Kurtz preforms both of these approaches to hip replacement surgery. The SuperPath and direct anterior approaches are the most tissue sparing and least invasive approaches to hip replacement surgery. They both allow the patient unrestricted post-operative activity in most situations.
The SuperPATH approach is a combination of the Superior approach championed by Stephen Murphy in Boston and the PATH approach (percutaneous assisted total hip) championed by Brad Penenberg in Los Angeles. Both the superior approach and the PATH approach were developed between 2002 to 2004. The main benefits of the SuperPATH approach are that the hip is not dislocated during the surgery, the leg length and offset are accurately restored, and the surgery is performed in a tissue sparing manner that allows for a quicker recovery.
A hip dislocation occurs when the femoral head is forcible removed from the hip socket, which can happen with major trauma like a car wreck or during most hip replacements. A vast majority of hip replacement surgeries begin with twisting and pulling the leg in order to dislocation the femoral head out of the socket. This dislocation may occur out of the front of the socket as in the anterior hip approaches or out of the back of the socket as in the posterior hip approaches. However, the SuperPATH technique makes dislocating the hip joint during surgery unnecessary. Preventing a post-operative hip replacement dislocation starts with eliminating the intra-operative hip dislocation. Avoiding the hip dislocation during a hip replacement surgery is accomplished by preparing the femoral bone first. In situ femoral preparation refers to reaming, broaching and implanting the femoral component without cutting the femoral neck and without dislocating the hip joint. Since the femoral head remains in the socket, the hip joint helps stabilize the leg during the femoral preparation. Because the femoral neck remains intact during the femoral preparation, the femur is stronger and less likely to fracture, a fact I presented at ORS in 2010. Interestingly, every orthopedic surgeon has at one time or another implanted a femoral IM nail into the femoral shaft without cutting the femoral neck or dislocating the hip joint. This in-situ femoral preparation just utilizes the same skill set every orthopedic surgeon already has for trauma cases (broken bones) and applies it to joint replacement cases.
I did my joint replacement fellowship with Dr. Murphy in Boston and became very comfortable with this superior approach. Dr. Murphy has multiple publications on the superior ic. Stephen B. Murphy, MD; THA Performed using Conventional and Navigated Tissue-preserving Techniques, CORR(453), pp. 160–167.
There are a handful of surgeons across the nation using this SuperPath technique: Dr. Jimmy Chow is in Phoenix, Az, Dr. Harbinder Chadha in Chula Vista, CA, Dr. Dean Olsen in Owatonna, MN, and Patrick Meere in New York, NY.
There are three unique aspects about the SuperPath hip replacement that a patient or surgeon should understand.
The hip joint is never dislocated. Every other surgical approach will dislocate the hip joint at one point or another. Most surgical approaches dislocate the hip joint immediately after reaching the joint. Other approaches will cut the femoral neck in situ and remove the head, but later dislocate the hip in order to implant the femoral stem in the femoral canal or attach the femoral head onto the femoral component. The entire superior approach is preformed with the femur and the acetabulum in an anatomic position. The leg is never twisted, rotated or pulled into an abnormal position. The components are inserted and put together inside the hip joint. The main purpose of this approach is to preserve the anterior and posterior hip capsule. When the hip is dislocated during other surgical approaches, either the anterior or posterior capsule has been cut, torn or disrupted. A good analogy to understanding this approach is building a ship inside a bottle. The entire total hip components in the superior approach could not be constructed outside of the hip capsule and then reduced into the joint because there is simple not enough space to get the femoral head over the acetabular rim and into the joint without cutting the hip capsule. Therefore, each component is inserted into the hip joint separately and the hip components are constructed inside the joint. A hip dislocation would be equivalent to removing the ship from the bottle, which is extremely difficult if the bottle has not been broken (i.e. the hip capsule has not been cut). A traditional approach would be equivalent of breaking open the bottle, placing the ship in the bottle, and then gluing the bottle back together.
Second, the femoral canal is prepared before the femoral neck is cut. This technique has many benefits. The femur is held in place by the intact femoral neck and the head located in the acetabular socket. Femur offset is maintained during the preparation of the femoral canal which makes entering the femoral canal with the reamers and broaches considerably easier. The femoral shaft and calcar are stronger because the femoral bone is intact and has not been cut with a saw, eliminating or at least decreasing intra-operative femoral calcar fractures (presented at ORS'10). The femoral anteversion can be accurately recreated because the surgeon is looking at the native femoral head during the insertion of the femoral component. Because the femur is held in place, leverage retractors greatly facilitate the exposure. The size of the patient is not a major factor in the exposure needed to perform the surgery. Therefore, almost every size patient can benefit from this approach. By inserting the femoral component before the femoral neck is cut, the surgeon can measure the distance from the femoral component and a fixed point on the ilium and accurately restore the leg length and offset. Click here to learn more about this leg length measurement technique and Dr. Kurtz's research study. Third, the surgeon works in between the interval of the posterior border of the gluteus medius muscle and the superior border of the short external rotators. The posterior capsule and short external rotators are preserved, which enhances hip stability. The hip abductors are protected, which helps prevent limping after surgery. The gluteus maximus muscle is spread and leverage retractors are used to protect the surrounding muscles, so they are not damaged during the insertion of tools and implants.
SuperCap Surgical Technique
The surgery starts by positioning the patient and the patient's leg in a position similar to one that the patient might sleep in bed. (leg adducted, flexed, and internally rotated). The patient's leg stays in this position for almost the entire case. The incision is usually 8 cm and does not typically need to be increased very much for larger patients. The incision starts at the tip of the greater trochanter and extends proximally in line with the femoral shaft.
Thesurgery starts by positioning the patient and the patient's leg in a position similar to one that the patient might sleep in bed. (leg adducted, flexed, and internally rotated). The patient's leg stays in this position for almost the entire case. The incision is usually 8 cm and does not typically need to be increased for larger patients. The incision starts at the tip of the greater trochanter and extends proximally in line with the femoral shaft.
|Fig. 1 - Patient Positioning
The gluteus maximus muscle fibers are spread in line with the incision. The posterior border of the gluteus medius is identified and leverage retractors help protect it and pushed the muscle forward during the case.
Fig. 2 - Piriformis released to expose superior capsule
The internal rotation of the leg facilitates moving the abductors out of the way for the femoral preparation. The piriformis muscle is identified and released. This muscle is released or injured during the insertion of any femoral prosthesis. The superior capsule is then incised and the superior femoral neck is exposed.
|Fig. 3 - Superior Capsulotomy
||Fig. 4 - Superior Femoral Neck
The femoral canal is opened with a straight reamer just as if the surgeon was going to insert a femoral nail.
Fig. 5 - Opening the femoral canal with a straight reamer
The medial femoral neck bone is removed with an osteotome and femoral broaches are inserted.
Fig 6 - Osteotome removes medial femoral neck bone
The femoral broaches are inserted down the femoral canal. Because the femoral neck is intact, the femur is stabilized and the broaching is easier.
Fig. 7 - Insertion of femoral broach
The final femoral broach is left in the femoral canal and used a template to show the surgeon where the appropriate femoral neck cut will be located. The real femoral prosthesis can also be inserted at this time instead of the femoral broach. The femoral neck is then cut with a saw and the femoral head is removed by inserting a threaded pin into the femoral head and pulling the head out of the socket.
|Fig. 8 - Femoral Neck Cut
The acetabulum is reamed with a special angled reamer. This angled reamer allows the surgeon to control the anteversion of the reamer without the femoral bone getting in the way simply by turning the handle towards the direction he/she intends to ream. During traditional approaches, a surgeon may find that the femoral bone inadvertently pushes his/her reamer in an wrong direction. Because this reamer is angled, the femoral bone does not limit or inadvertently push the reamer in the wrong direction.
The acetabulum is reamed with the PATH reamer (not shown). This PATH reamers allows the surgeon to approach the acetabular socket at an angle that is not dependent on the incision used to implant the femoral component.
Fig. 10 - Angled Reamer
The acetabular component is implanted with the PATH impactor.
Click here for additional information regarding traditional hip replacement and risk of a hip replacement.
Click here to know difference between SuperPath and Direct Anterior