NEW YORK—October 1, 2009
“It is a small minority of patients who need further surgery early on, but that is a lot of trips back to the operating room considering how much surgery is done,” said Robert Marx, M.D., an orthopedic surgeon in the Sports Medicine and Shoulder Service at Hospital for Special Surgery. “This is the largest study to look at factors that may affect subsequent surgeries after ACL reconstruction.”
ACL injuries are common in athletes. Some studies estimate that as many as 175,000 ACL reconstructions are done each year in the United States. While investigators have studied technical aspects of the surgery and outcomes and safety in small groups of patients, few studies have examined the frequency of reconstruction and subsequent knee surgery in a large population of patients.
To remedy this, researchers at Hospital for Special Surgery turned to the Statewide Planning and Research Cooperative System (SPARCS) database. This database, run by the New York State Department of Health, provides a census of all hospital admissions and ambulatory procedures within the state of New York. Investigators identified all ACL reconstructions performed between 1997 and 2006; the total was 70,547. They found that the frequency of ACL reconstruction increased from 6,178 in 1997 to 7,507 in 2006, a 21.5% increase. “The rate of ACL surgery went up dramatically during the study period,” said Dr. Marx.
The investigators then tracked how many of these patients had any subsequent operation within one year or subsequent ACL reconstruction on either knee, among other factors. “The SPARCS database lets us look at a very large number of patients with longitudinal followup, so we can see what happens to them as opposed to just what happened during hospital admission. We can follow them for a few years,” said Dr. Marx.
The researchers found that the frequency of subsequent surgery on either knee within one year was 6.5% (4,595 patients), and patients were more likely to have subsequent surgery if they were female or treated by a surgeon who performed a low volume of ACL surgeries.
“We know that a risk of an ACL tear is much higher in females, between two- to ten-fold, but this is the first study to show that women are at a higher risk of subsequent surgery after ACL reconstruction,” Dr. Marx said.
Investigators also found that 1.9% (1,318 patients) of patients who underwent ACL reconstruction had a subsequent ACL reconstruction within one year. Patients were more likely to have a subsequent reconstruction if they were younger than age 40 and treated at a hospital that performed a low volume of ACL reconstructions.
“Younger patients under 40 are at a higher risk and that is likely related to the activity level. This has been my suspicion, but it hasn’t been shown in a population this large before,” explained Dr. Marx. “As we get older, as a group we tend to do less sports and high-risk activities, so people under 40 have a higher risk of needing more ACL surgery.”
Dr. Marx said he was not surprised that volume was found to be a factor tied to outcomes. “I think that like everything in surgery and medicine, practice makes perfect and the more someone does something, the better their results are going to be,” he said. “Volume, like many things in medicine, is a factor in ACL surgery.” More than 800 ACL surgeries are performed each year at Hospital for Special Surgery.
Dr. Marx pointed out that all people who tear their ACL do not need to undergo reconstruction. If a person is not an athlete playing a sport that involves cutting and pivoting activities such as soccer or basketball, they can be treated nonoperatively in some cases. There are take home messages from this paper, however, for patients who choose to undergo ACL reconstruction.
“Patients need to understand that younger individuals who undergo an ACL reconstruction have a higher risk of retear. The risk is not the same for all patients,” said Dr. Marx. “Patients also need to know that being operated on by a lower volume surgeon has a higher risk of reoperation.”
Dr. Marx, an orthopedic surgeon who specializes in ACL surgery at Hospital for Special Surgery is Professor of Orthopedic Surgery and Professor of Public Health at Weill Cornell Medical College and also Director of the Foster Center for Clinical Outcome Research at Hospital for Special Surgery.
Other authors of the study are Stephen Lyman, Ph.D.; Panagiotis Koulouvaris, MD; Seth Sherman, M.D. Huong Do, M.A. and Lisa A. Mandl, M.D., M.P.H.
About HSS | Hospital for Special Surgery
HSS is the world’s leading academic medical center focused on musculoskeletal health. At its core is Hospital for Special Surgery, nationally ranked No. 1 in orthopedics (for the eighth consecutive year) and No. 3 in rheumatology by U.S. News & World Report (2017-2018). Founded in 1863, the Hospital has one of the lowest infection rates in the country and was the first in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center four consecutive times. The global standard total knee replacement was developed at HSS in 1969. An affiliate of Weill Cornell Medical College, HSS has a main campus in New York City and facilities in New Jersey, Connecticut and in the Long Island and Westchester County regions of New York State. In 2017 HSS provided care to 135,000 patients and performed more than 32,000 surgical procedures. People from all 50 U.S. states and 80 countries travelled to receive care at HSS. In addition to patient care, HSS leads the field in research, innovation and education. The HSS Research Institute comprises 20 laboratories and 300 staff members focused on leading the advancement of musculoskeletal health through prevention of degeneration, tissue repair and tissue regeneration. The HSS Global Innovation Institute was formed in 2016 to realize the potential of new drugs, therapeutics and devices. The culture of innovation is accelerating at HSS as 130 new idea submissions were made to the Global Innovation Institute in 2017 (almost 3x the submissions in 2015). The HSS Education Institute is the world’s leading provider of education on the topic on musculoskeletal health, with its online learning platform offering more than 600 courses to more than 21,000 medical professional members worldwide. Through HSS Global Ventures, the institution is collaborating with medical centers and other organizations to advance the quality and value of musculoskeletal care and to make world-class HSS care more widely accessible nationally and internationally.