An investigation by researchers at Hospital for Special Surgery reveals that individuals who undergo anterior cruciate ligament (ACL) reconstruction are approximately 4 to 5 times more likely to undergo further ACL reconstruction, if the initial operation was performed by a surgeon who has carried out less than 60 operations.

Furthermore, the researchers found that taking part in subspecialty orthopedic fellowship-training program did not enhance the learning curve of young surgeons carrying out ACL reconstructions. The study was presented at the annual meeting of the American Academy of Orthopedic Surgeons, held February 7-11.

Robert Marx, M.D., an orthopedic surgeon in the Sports Medicine and Shoulder Service at Hospital for Special Surgery (HSS) in New York City, professor of Orthopedic Surgery and professor of Public Health at Weill Cornell Medical College, director of the Foster Center for Clinical Outcome Research at HSS , and coauthor of study, explained:

“Conventional wisdom is that a trained surgeon should have excellent results once they have completed their training, but there is a learning curve to ACL surgery and what we have found is that in the early career volume or learning curve, surgeons’ outcomes are not as good as later outcomes for ACL reconstruction. Maybe we need to rethink how we train our surgeons in light of this.”

Dr. Stephen Lyman, director of Epidemiology and Biostatistics at HSS, who presented the research, concurs. Lyman said:

“We may not be training our sports medicine specialists well enough to perform this complex procedure if the learning curve is still this steep after finishing their fellowship.”

The ACL is one of the four major ligaments of the human knee, and one of the most commonly injured. Each year in the U.S., around 100,000 ACL reconstructions are carried out.

Although doctors have known for years that outcomes in surgery are associated to volume, for instance, the more times a surgeon performs ACL reconstruction, the more proficient they become, with fewer individual’s requiring further surgery. This is the first study to examine what the learning curve actually looks like.

Dr. Marx said:

“The question was, on the upswing, how long does it take you to become proficient?”

Furthermore, in the past few years, more and more doctors have attended subspecialty sports medicine fellowship training programs, following their orthopedic surgery training. However, there is little knowledge about the impact of these programs on acquiring better knowledge of ACL reconstruction.

In order to fill these two knowledge gaps, the team identified all ACL reconstructions performed between 1997 and 2006, by surgeons who carried out their first ACL reconstruction in 1997 or later, by using data from the New York State Department of Health database that contains information on all ambulatory surgical procedures and hospital admissions, within the state of New York.

The researchers then analyzed medical records to identify which patients underwent additional ACL surgery. The team controlled case-mix factors, such as sex, comorbidities, concomitant surgery, insurance type, and age.

During the study period, the team identified 12,778 ACL reconstructions carried out by 320 surgeons. The researchers then compared the chances that a patient would require further ACL reconstruction if:

  • the patient is one of the first 10 cases of a surgeons career
  • if the patient fell between 11 and 60 cases of a surgeons career
  • between 61 and 120
  • between 121 and 150
  • or if they had the procedure after the surgeon had performed over 150 cases

Dr. Lyman explained:

“For several non-orthopedic surgical procedures 10 cases are considered necessary to obtain clinical competence.”

They discovered that patients who were one of the surgeons first 10 cases were around 5 times more likely to undergo additional ACL surgery, compared to individual’s whose surgeon had performed more than 150 ACL reconstructions. Case 11 to 60 patients, were 3.7 times more likely to have further ACL reconstruction, patients in the 61 to 120 groups were 3.0 times more likely, while those in the 121-150 group were 1.4 times likely. Overall, the one year prevalence of additional ACL reconstruction within one year was 1.7%.

No considerable link was found between sports fellowship training and subsequent ACL reconstruction.

Dr. Marx explained:

“Ultimately, the true learning is practice. That is why they call it practice. ACL reconstruction is a complex procedure, with many surgical steps, that may be more technically difficult at the beginning of one’s career compared to certain other procedures that are less demanding and don’t require quite as much practice to get good at. This study shows that our training for ACL might not be adequate.”

According to Dr. Marx:

“Perhaps doctors should have a little more autonomy at the end of their training or they should be evaluated differently. Using medical simulators in training is another option.”

The Agency for Healthcare Research and Quality’s Center for Education and Research in Therapeutics funded the study.

Other co-authors of the study include Annette Oesterhelt, Stephen Lyman, Ph.D., Hassan Ghomrawi, Ph.D., MPH, Huong Do, M.A., and Joseph Nguyen, MPH.

Written by Grace Rattue