Minimally Invasive Surgery May Improve Outcomes for Patients Undergoing Joint Repair

Less pain, shorter hospital stays and quicker recovery times might soon become reality for more patients undergoing joint replacement surgery and other types of joint reconstruction as a result of advancements in Minimally Invasive Surgery (MIS). This topic was discussed in detail today at a press briefing on the MIS approach for hip, knee and shoulder surgery at the American Academy of Orthopaedic Surgeons' (AAOS) 70th Annual Meeting in New Orleans, La.

Orthopaedic surgeon, Kristaps J. Keggi summarized results of his study involving a minimally invasive anterior approach to total hip arthroplasty, a specific technique that he developed and along with his associates, successfully used in over 6000 patients over a 10-year period. "Minimally invasive surgery for total hip arthroplasty has reliably shown in thousands of patients to lead to smaller incisions, less blood loss, fewer complications and an earlier rehabilitation than traditional total hip arthroplasty," said Keggi.

The authors of the study followed up with more than 2000 primary total hip arthroplasty patients encompassing a wide range of patients, from 17 to 94 years of age weighing from 90 to 450 pounds. The results are quite satisfactory, with the average operative time under one hour via an incision that is usually about 8 centimeters long. There were 28 dislocations among 2132 total hips (1.3%), 12 of which occurred in the immediate post-operative period. There were a total of 17 clinically significant thromboembolic events (0.8%), which included 11 pulmonary emboli (0.5%) and 6 clinically significant deep venous thromboses (0.3%). The average intra-operative blood loss ranged from 0.35 units for the simple hips to 0.72 units for the complex hips.

Another group of surgeons have completed early trials, indicating promising results for patients undergoing total knee arthroplasty (TKA). "Minimally invasive surgery has been used for unicompartmental (partial knee joint replacement) since the early 1990s. It's only logical that the MIS approach would eventually be applied to total knee arthroplasty," said Alfred J. Tria, MD at the briefing. Tria co-authored the study entitled "Minimal Incision TKA: The Future of Knee Arthroplasty."

Tria and Thomas Coon, MD, co-author of the study, are a part of a team of developers working on next generation implants. Early results from the 70 MIS total knee arthroplasties completed over the past nine months indicate less intra-operative blood loss, shorter hospital stays and increased range of motion than a comparable group of patients who underwent the standard arthrotomy technique. Tria and Coon are among a very limited number of surgeons who are performing this minimally invasive procedure. The average age of the patients in the study was 67 with a range from 51 to 84 years. There were 35 females and 31 males.

Now that the surgical approach for MIS TKA has been established using tried and proven prosthetic designs that have published results, the authors plan on taking it to the next level by modifying the prostheses to facilitate implantation. The final goal will be to add computer assistance for even greater accuracy and reproducibility. In terms of results, the follow-up of this study is short term and can only indicate trends at best. Long-term research on patient outcomes will need to be conducted and compared to existing data on well-established arthroplasties. For now, the procedure will not be widely available.

MIS is also being used in the shoulder for rotator cuff repair, repair of shoulder dislocations, and repair of shoulder fractures. "While MIS definitely provides patients with benefits such as smaller incision, shorter hospital stay and quick recovery," said Evan Flatow, MD at the briefing. "It is still up for debate among many orthopaedists whether or not the treatment holds up as well as the open approach for the long term." Several studies presented at this meeting address the role of MIS in shoulder surgery.

All of the doctors on the panel agreed that although MIS shows great promise for joint surgery, no matter what incision or approach is used -- it is still major surgery and all of its related problems of tissue healing, overall recovery and the small but real percentages of major complications still exist. More studies need to be done on a significant group of patients to evaluate the long-term efficacy of these procedures.

The 26,047-member American Academy of Orthopaedic Surgeons (www.aaos.org) or (http://orthoinfo.aaos.org ), is a not-for-profit organization that provides education programs for orthopaedic surgeons, allied health professionals and the public. An advocate for improved patient care, the Academy is participating in the Bone and Joint Decade (http://www.usbjd.org ), the global initiative in the years 2002-2011 to raise awareness of musculoskeletal health, stimulate research and improve people's quality of life. President Bush has declared the years 2002-2011 National Bone and Joint Decade in support of these objectives. The Academy's Annual Meeting is being held February 5-9, 2003, at the Ernest N. Morial Convention Center in New Orleans, La.