Statistical data on orthopedic surgeries performed in the U.S. show that anterior cruciate ligament (ACL) injuries are common. The number of ACL surgeries is on the rise and not because there are more surgeons around to do the surgery or because there are more people in general (as measured by the U.S. census). More people are active and involved in sports and activities that can lead to trauma and knee injuries.
Knowing that ACL reconstruction is a common procedure, it’s important to look at the results. How safe is the procedure? Do the results hold up over time? How many patients end up having complications or another surgery later? In a recent study, a statewide hospital database from New York was used to gather information on the results of ACL reconstruction. In this study, they measured 1) number of ACL reconstruction surgeries done between 1997 and 2006, 2) how often these patients need another surgery later, and 3) risk factors to predict readmission or second surgeries.
Using hospital identification numbers and physician license numbers, the researchers were able to calculate annual volume for the 263 facilities and the 1513 surgeons involved. Basic information about over 70,500 patients who had an ACL reconstruction was collected (e.g., age, sex, type of insurance coverage, and the presence of other health problems).
As you have heard, age was a big factor. The patients who had the highest readmission rate (within 90 days) were older men (more than 40 years old) or those who had other health problems. But there was one other important factor. Patients were also more likely to be readmitted for problems if they were operated on by a lower-volume surgeon in a lower-volume hospital. Low volume was defined as the surgeon performed less than six ACL reconstructions per year in a hospital where less than 24 total procedures of this type were done each year.
The risk of having a subsequent ACL surgery (within one-year) was highest among patients who were younger than 40 (especially those who were younger than 20 years old). That may be because they are more active and less likely to follow guidelines on restrictions following surgery. One other risk factor for later problems requiring additional surgery was having a meniscectomy (meniscus removal) at the time of the initial ACL reconstruction procedure.
Age is an important factor, but it isn’t the only one. The patient’s general health, the surgeon’s experience, the presence of other knee injuries, and patient activity level must all be taken into consideration. Anterior cruciate ligament reconstruction is a technically demanding procedure. The complexity of the procedure is a risk factor of its own. Surgeon and hospital volume are important but there are many other possible risk factors yet to be explored when trying to isolate what it is that causes patients to require readmission or subsequent surgery. Future studies are needed to look at the many possible risk factors.