Surgeon Skill vs. Patient Outcome: That’s the Posterior v. Anterior Debate as Sculco Takes on Hozack

Is anterior too difficult for the rank and file surgeon? “We must ask whether the anterior approach is good for the everyday orthopedic surgeon who is doing 25-30 hip replacements a year, ” says Tom Sculco. But that’s not the point, counters Bill Hozack, patient outcomes are why the anterior approach is the way to go. “With the anterior approach you preserve the posterior capsule, eliminate the need for restrictions after surgery, and this approach enhances patient confidence and speed of recovery.”

This week’s Orthopaedic Crossfire® debate is “The Posterior Approach: Optimizes THA [total hip arthroplasty] Outcome.” For the proposition is Thomas P. Sculco, M.D. of The Hospital for Special Surgery in New York and against the proposition is William J. Hozack, M.D. from the Rothman Institute in Philadelphia. Moderating is Clive P. Duncan, M.B., F.R.C.S. (C) from the University of British Columbia in Vancouver.

Dr. Sculco: “There are many ways to get into the hip joint, and in expert hands all will yield excellent results. The two most common in the U.S. now are the anterior approach and the posterolateral approach. The latter can be easily extended, the blood loss is less, and it’s expeditious. Its main disadvantage is that it’s been reported to have a higher dislocation rate.”

“The incision I use is primarily a lateral approach, although I come in posteriorly for my deep dissection. One-third of the incision is above the greater trochanter, two-thirds below; it’s a linear approach. On the femoral side your visualization should be a full circumferential view of the neck of the femur so that you won’t violate the neck on the insertion of your femoral component.”

“Some years ago we looked at almost 1, 500 total hip replacements through this less invasive posterolateral approach. Follow-up was about 10 years, and the skin incision was 8.4 centimeters. The radiographic evaluation was quite good: abduction (42.2), cement (95% A or B), stem (93% neutral). Complications: dislocation rate was 1.2%, femoral fracture rate was 0.3%, and neuropraxias of the sciatic nerve is a problem if you put excessive tension posteriorly. We learned that early on when we tried to make these incisions too small. Wound complications were dramatically small: four hematoma and three infections. Many of these patients only stay in the hospital for two days.”

“As for anterior hip replacement, it has been popularized on the Internet in the U.S. There are 62, 000 Web sites. But is this a good approach for the everyday orthopedic surgeon who is doing 25-30 hip replacements a year? The claims made are that it is tissue sparing and there is no injury to muscle, that there is less pain, and that the recovery is faster. Is there really evidence to support these assumptions? There is actually very little in the literature.”

“The disadvantages: Most patients are placed on a special OR table which must be purchased for this approach; many surgeons use intraoperative fluoroscopy; the femoral exposure is more difficult, particularly in larger patients and male patients; the OR time is increased…and are the complications higher?”

“A cadaveric study by Meghini disputes the fact that there is no muscle injury in the anterior approach. In the posterior approach there is injury to the glutei and the abductors; however, in the anterior approach there was significant injury to the tensor fascia lata and the external rotators.”

“In another study, Pilot looked at a cytokine evaluation of muscle injury. When comparing the anterior and posterior approaches there was no difference in these sensitive markers of tissue injury in either approach. As for dislocation, that’s been advocated as an advantage of the anterior approach. Looking at several studies advocating anterior approaches, we see that the dislocation rate is not significantly different from my series I reported earlier (Siguier, 0.96%; Matta, 0.61%; Kennon, 1.3%; Sariali, 1.5%; Sculco, 1.2%).”

“Periprosthetic fracture: Dr. Matta is the advocate and early developer of the anterior approach. In a paper he published he had a 2.4% fracture rate in an expert’s hands; my fracture rate with the posterolateral approach was 0.3%. Lateral femoral neuropraxia is also a problem; that’s been reported in as high as 67% of patients. Much of it is transitory, but it is still bothersome to the patient.”

“In a series of five community surgeons in five community hospitals with 250 hip replacements done anteriorly, the surgical time is nearly three hours; blood loss was nearly two units, with a 9% complication rate. In summary, keep it simple…disaster is always a threat.”

Dr. Hozack: “As Clive knows, we Canadians have a different perspective on things. The goal of total hip replacement should be a perfect result. But we don’t always achieve that goal. What is perfect? No pain at any time, no restrictions at any time, a faster recovery (days not months), no muscle damage, normal range of motion (ROM), no second operation, no complications.”

“Obviously there are certain things that are unrelated to the approach, such as the amount of pain you experience, the ROM you achieve, and the need for a second operation. But the other four may give you pause and make you think of trying a different approach. These are: no restrictions at any time postoperatively, the speed of recovery, the level of muscle damage, and the lack of early or late complications.”

“Hip restrictions that are imposed on the patient are not good for that patient. We force them to buy certain devices that are difficult to transport out of the house to restaurants, etc., and are actually very expensive. People like to cross their legs, get in their cars and drive, etc…and the posterior approach limits that in the very beginning because it violates a significant number of structures. If you add up the number of muscles that are cut, you see that the posterior approach cuts the most number of muscles.”

“So there is a rationale for an anterior approach of some sort. It preserves the posterior capsule, eliminates the need for restrictions after surgery, and it enhances patient confidence and speed of recovery. There are data in the peer-reviewed literature (Nakata et al, JOA 2009) suggesting that in the early post-operative time there is a faster recovery with an anterior approach as opposed to a posterior approach.”

“Soft tissue damage affects functionality and the consequences are severe: weakness, limp, soreness, heterotopic bone formation, and general disappointment for the patient and the surgeon. And there are good alternative approaches available that go between muscles, between nerves, that don’t damage muscle, and create less muscle trauma.”

“So consider an alternative approach that spares one of the biggest muscles around the hip—the gluteus maximus. We always forget to talk about that muscle, and this is routinely violated in the posterior approach. And another approach might spare the gluteus medius and minimus muscles during surgery.”

“Bergin et al published an article in the Journal of Bone and Joint Surgery in 2011 suggesting that inflammatory markers are decreased with a less invasive approach. And if you’re worried about instability…if you look at causes for revision in the U.S. the number one cause is instability of the hip. In expert hands it’s not a problem, but in the general population of surgeons instability is a big deal.”

“So consider coming over from the back side…don’t fight it so much. If you learn it from experienced surgeons then you don’t need a special table—you can do it on a regular table and it doesn’t require any special expenses. It does require special instrumentation, but that is true of every approach.”

Moderator Duncan: “Bill, when can we expect the first prospective randomized study which is really going to put this issue to bed once and for all?”

Dr. Hozack: “There is one prospective randomized study that I did comparing it to direct lateral.

Moderator Duncan: “Because the prospective randomized studies comparing things to the direct lateral usually wins because of the transgluteal is so disruptive to the function of the hip. I mention that because the G3—the Watson Jones approach—which is really just two fingerbreadths behind what you use—showed that there is really no advantage to changing your approach mid-career. Tom, you’re the leader of a prominent residency program in New York. Are we now at a point where we should introduce this to our residency programs?”

Dr. Sculco: “I’ve done the anterior approach to the hip, and we have a number of surgeons at our facility that use the anterior approach…so my residents do see the approach. As they rotate through my service I always ask them what they think. They say that they think anterior is a more difficult approach than posterior. I think surgeons should know all the approaches to the hip, but they should find an approach that they’re most comfortable with and they get the best results.”

Moderator Duncan: “Thank you.”

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