“The questions are, ‘the direct anterior approach by whom, which outcomes, and compared to what, ” says José Rodriguez. Brad Penenberg notes, “The direct anterior approach is quicker and people recover sooner, but is it safer in everybody’s hands? Check your iPhones now to see if you’re invited to another anterior hip course.”
This week’s Orthopaedic Crossfire® debate is “The Mini Anterior Approach: Optimizing Total Hip Outcome.” For the proposition is José Rodriguez, M.D. Lenox Hill Hospital in New York; against the proposition is Brad Penenberg, M.D. of Cedars Sinai Medical Center in Beverly Hills. Moderating is William J. Maloney, III, M.D. from Stanford Hospital and Clinics.
Dr. Rodriguez: “There is a long history of enmity between the cities that Dr. Penenberg and I represent. However, Dr. Penenberg hosted me and taught me some of his tricks…so we’ve decided to be very gentlemanly in this discourse.”
“The questions become direct anterior approach (DAA) by whom, which outcomes, and compared to what. I can only discuss what I know, and that is the outcomes that we’ve generated by carefully analyzing our data. We have a study that should be published in the Journal of Arthroplasty toward the end of 2014. We ask, ‘Is there faster recovery after DAA compared to posterior?’ This is a Level 2 study with consecutive patients and specific inclusion criteria. There were three surgeons; one did DAA and two did the posterior approach. All were trained by the same master surgeon. There was a similar design and bearing surfaces in both arms and uniform surgical technique among the patients for the DAA. It was a standard OR table with a table-mounted retractor and anterior capsulotomy and selective releases. The posterior approach was done in the lateral position with repair of the capsules and muscular structures.”
“The tools we used were Timed Up and Go Test, functional independent measures, a motor component, and a milestone diary. Preoperatively, the demographics and the milestones and outcomes were exactly the same. Early recovery in the hospital…we saw a clear benefit to the DAA group for all of the functional measures. There was no significant difference in length of stay. By two weeks, only the Timed Up and Go Test remained significantly better—the other measures had normalized. By 6 and 12 weeks there was no difference. The diary that the patients created demonstrated no difference; there were no differences in general health outcomes. At one year there was no difference between any of the cohorts.”
“The complication rate between the different cohorts was about the same, so this demonstrates that up to two weeks there was a clear benefit in terms of recovery in specific criteria that were assessed. However, by six weeks everything had normalized; there was no difference in recovery speed, activities of daily living, or surgical complexity. So both provide excellent outcomes; DAA was somewhat more rapid (two weeks) which then disappeared.”
“As for gait analysis we analyzed 10 DAA patients and 11 posteriors (all my patients) who had comparable preoperative demographics and clinical scores. Motion analysis and reflective markers were assessed preoperatively and at six months. Movement in the frontal and saggital planes improved to the same extent. There was a slight increase in the transverse plane of motion when the patients walked. So during the gait cycle the degree to which the foot internally and externally rotated increased in the DAA group and did not change in the posterior group.”
“Regarding hip strength, we took 15 patients from two cohorts and did prospective isometric strength testing preoperatively and postoperatively. The demographic and clinical variables were the same between the two groups. Between the preop and the six week there was weakness in external rotation in the posterior group; there was weakness in flexion in the anterior group. By three months those changes had diminished. There was still a bit of external rotation weakness in the posterior group, but the flexion weakness had resolved in the anterior group.”
“And socket placement precision with the use of a C-arm? There was clearly an improvement in my surgical precision; in those 300 cases I had one dislocation in the posterior group. I suggest do what feels right; there is no perfection…and choose a surgeon you trust.”
Dr. Penenberg: “We see claims in the lay press, endorsements by academicians saying that it leads to quicker recovery, and patients coming in with printouts from websites asking for an operation that cuts no muscles or tendons. Check your iPhones now to see if you’re invited to another anterior hip course. It’s quicker and people recover sooner, but is it safer in everybody’s hands?”
“There is a significantly higher complication rate with the anterior approach, and there are multiple references describing lateral femoral cutaneous nerve injury (17-65%), trochanteric fractures, and proximal femur fractures. Dr. Rodriguez was eloquent in his presentation at the AAOS [American Academy of Orthopaedic Surgeons] a couple of years ago when he described the tendon releases associated with an anterior approach. So this is perhaps a new anterior approach.”
“It’s almost impossible to satisfactorily place a prosthesis without disturbing the conjoint and nearby tendons. Stems could be undersized and lead to subsidence and fracture. So it appears that there is a new DAA and I suspect that there’s possibly a direct posterior alternative that can achieve clinical anatomic and radiographic parity.”
“There is a clinically and anatomically equivalent option with a modified posterior approach, with multiple papers coming out almost every month. With this there are no nerve injuries, only rare deep vein thrombosis (DVT), rare trochanteric fractures, rare dislocation, no wound problems, heterotopic bone, extremely shortened hospital stay, and minimal narcotic intake postoperatively.”
“The problem with the comparison studies that we’ve seen—and José didn’t clarify what he was comparing his DAA to—but most of the comparative studies are in direct comparison to the conventional posterolateral Moore type approach with multiple tendon releases and extension into the iliotibial band (ITB).”
“Optimize means rapid return to function postop day one, preservation of key anatomic structures, minimal preop medication, a single shot spinal Marcaine only (nothing that’s likely to make the patient ill), rapid mobilization, minimal blood loss, and minimal postop narcotics.”
“The other part of the Holy Grail of optimization is eliminating precautions postoperatively. With the posterior approach at one day postop there are no restrictions, and there is preservation and repair of the posterior capsule. Precise component placement is also part of the optimized total hip. Radiographic optimization…we can achieve this using intraop digital radiography in a lateral position.”
“The anatomy of the optimized hip is when we don’t crush, shred, resect or otherwise brutalize key anatomical structures. I believe that what the DAA and modified posterior approaches might have in common is preservation of the iliotibial band and the quadratus, and a careful approach to the gluteus medius muscle. The easy bailout option is readily available with a modified posterior approach. You can extend it into the ITB at any time. Marketing at times confuses us and says that because of the anterior approach the patient can return to his baseline status. So it’s incorrect to say that the DAA optimizes outcomes in total hips. It’s not whether you use a DAA or posterior approach, but whether the surgeon can spare these key structures and can accurately apply intraoperative imaging.”
Moderator Maloney: “José, one minute.”
Dr. Rodriguez: “I’ve witnessed many different types of surgeries, and those surgeons who are at the podium have developed a judgment over the course of their learning processes. The judgment is what provides the quality…not an approach.”
Dr. Penenberg: “Most of the papers presented here and in the literature are done so by high volume surgeons. My biggest concern about the DAA is that as surgeons are attempting to learn the operation patients are being harmed. It’s important that we communicate to our patients what the realities are when they come in asking for the anterior approach. So I agree, it’s not anterior or posterior, it’s how the operation is done—and addressing the key anatomical structures.”
Moderator Maloney: “José, I think what many surgeons object to is the marketing that surrounds the DAA. Some of the claims clearly aren’t supported by the data. There may be a slight advantage in the first week or two as far as getting moving, but by six weeks it really doesn’t matter. What does matter is what Larry Dorr discussed: restoring the center of rotation. How do you respond to the marketing issue?”
Dr. Rodriguez: “It’s deeply annoying. I’ve tried to address that by discussing the things we actually do. You can’t do this operation—not uniformly—without getting the exposure.”
Moderator Maloney: “How much do you think the patients’ expectation of doing well and getting up and going fast actually influences that early functional outcome?”
Dr. Rodriguez: “Profoundly. This person is invested in what they are doing.”
Moderator Maloney: “Both of you comment on how you use intraoperative imaging to check your parts position and get your leg lengths right.”
Dr. Rodriguez: “We have a teaching center, so residents and fellows are each doing a third of the cases. We use the X-ray as a means of teaching the residents where they are. I make them use the intraoperative landmarks—transverse ligament, the anterior and posterior walls—and preoperatively plan the cup size using those landmarks. So if we’re one or two before the plan size that’s when we get the image in order to teach them.”
Dr. Penenberg: “While the patient is in a lateral position we get a trial radiograph. We do trial range of motion, put the acetabular component in, do the traditional methods of assessing limb length, range of motion and stability, and then we get an AP pelvis X-ray.”
Moderator Maloney: “José, what about your complications with the DAA?”
Dr. Rodriguez: “Before that, regarding the socket placement…my learning curve for putting in the cup has involved thinking about where exactly the anterior wall is because when I first started I had two anterior dislocations. So I started to antevert less…then came the groin pain. We’ve gone to sizing within the anterior wall, so my cups now are one to two sizes smaller than through the posterior approach.”
“As for complications, understanding the soft tissue releases so the femur can be delivered properly and uniformly is the most important thing. So you must understand the anatomy, and release sequentially until the femur is clearly visible and modifiable. And the lateral cutaneous nerve is an issue that arises, and I tell my patients that 40% of patients will be numb so they should expect it.”
Moderator Maloney: “Thank you.”
Please visit www.CCJR.com to register for the 2014 CCJR Winter Meeting, December 10 – 13 in Orlando.
