Copyright © 2008 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Andrew A. Freiberg, MD*,
Massachusetts General Hospital, Boston, Massachusetts
Posted May 2008
The article presented by Pagnano et al. is an outstanding
example of how to properly evaluate a new prosthesis or surgical technique.
There are many issues surrounding orthopaedic care that would benefit from an
evidence-based approach. This study set out to see if there were differences in
short-term outcome between two procedures.
Physicians as well as patients were excited when the first
two-incision total hip arthroplasty procedures were reported. This minimally
invasive technique was theoretically associated with less postoperative pain, less
blood loss, faster recovery, and reduced overall morbidity. This concept
challenged the conventional wisdom that "incisions heal side-to-side, not end
to end," that maximal visualization of osseous structures is essential to ensure
stable implants, and that, in general, a three-month recovery time should be
expected. Conventional arthroplasties were often performed with the patient under
general anesthesia, with liberal use of intravenous narcotics, with delayed
mobilization, and with the patient staying in the hospital for a week.
Early adopter surgeons tried a variety of minimally invasive
techniques with variable success. As part of the "new thinking," surgeons and
anesthesiologists modified anesthetic and/or pain management protocols. It is
our nature as orthopaedic surgeons to innovate and not necessarily to imitate.
This has led to a variety of experiences—some positive, and some with dramatic
rates of complication. Throughout the early and current stages of interest in minimally
invasive surgery techniques, proponents have generally stated that only
selected patients should be candidates for these procedures. Patients with
straightforward surgical anatomy, thin body habitus, overall good health, and a
personal interest in a quicker, more intensive early rehabilitation are
probably best suited for these procedures. This purposeful selection bias
allows for focused use of limited resources and may lead to a lower
complication rate. In addition, selection of younger or more motivated and/or
enthusiastic patients may in fact improve patient outcome scores.
Clearly, the major strength of this study is that it is a
prospective, randomized trial of total hip arthroplasty in consecutive patients
from the lead author's practice. These seventy-five patients were enrolled over
a period of fifteen months, and both the patient and the surgeon were blinded
to the planned procedure until it occurred. All patients received the same uncemented
implants, the same pain-management regimen, and the same physical therapy
protocols. Every effort was made to be true to the spirit of the study, and
patients were encouraged to progress as quickly as possible.
The demographics were quite similar between the two groups;
however, there was a trend toward faster functional recovery in the
mini-posterior-incision group. It should be noted that the most statistically
significant functional difference in the time it took to achieve functional
milestones was with regard to the discontinuation of the use of a walker or
crutches (p = 0.01). Differences in time until discontinuation of all support
were also statistically significant, but with a p value of 0.04. Careful review
of the SF-12 scores did not reveal any significant differences.
Pagnano et al. conclude that the thirty-six patients who
underwent two-incision total hip arthroplasty had a slightly slower early
recovery and rehabilitation when compared with the patients in the
mini-posterior-incision group.
This study is important because its design and execution is
of the highest caliber. What remains is the question—are two-incision minimally
invasive surgical procedures worth the time and work for a selected patient
population?
This study also causes us to reflect on the manner in which
our specialty advances. With the introduction of new surgical techniques,
implants, and anesthetic regimens, there is initial excitement and subsequent modification
of methods. It is incumbent on us as careful practitioners to study these early
results—particularly those reported in level-I studies—so we can learn if what
is new is also better. It is only through the work of such investigators as our
colleagues at the Mayo Clinic that we can learn what is best for our patients.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. the author or a member of his or her immediate family received, in any one year, payments or other benefits in excess of $10,000 or a commitment or agreement to provide such benefits from a commercial entity (Zimmer and Biomet). Also, a commercial entity (Zimmer and Biomet) paid or directed in any one year, or agreed to pay or direct, benefits in excess of $10,000 to a research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his or her immediate family, is affiliated or associated.
|
