Primary reconstruction of the anterior cruciate ligament (ACL) generally results in high levels of patient satisfaction. But as the number of primary ACL reconstructions increase, the potential for revision surgery also rises. Patients who have had good results after a primary ACL reconstruction may expect similar results after revision surgery.

But according to Rick W. Wright, MD, such expectations may be misplaced. In reporting on “Patient-Based Outcomes of Revision ACL Reconstruction: 2 Year Results from the MOON (Multicenter Orthopaedic Outcomes Network) Cohort,” Dr. Wright said that “revision ACL reconstruction resulted in a significantly worse outcome.”

The MOON consortium is a National Institutes of Health-funded, hypothesis-driven, multicenter, prospective cohort study of patients undergoing ACL reconstruction. Six sites and eight surgeons were involved, and a variety of grafts were used. Patient-based outcomes were measured by the Knee Injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee Subject Form (IKDC), and the MARX activity level score. In all of these scoring systems, higher numbers reflect better outcomes.

Of the 47 patients who met the inclusion criteria (revision ACL reconstruction without additional osteotomy, collateral or posterior cruciate ligament surgery, performed in 2001), 39 (29 males and 10 females) were available at 2-year follow-up. Median results for primary and revision groups are shown in Table 1. In all cases except MARX, scores are measured from 0 (worst possible) to 100 (best possible). MARX scores are measured from 0 (less than once a month) to 4 (four or more times a week) in four functional areas (total possible score of 16).

Although this is a small, short-term study, researchers anticipate the ability to do continued follow-up. “Our results demonstrate that revision ACL reconstruction results in statistically and clinically significantly worse outcomes as measured by validated-patient based outcome measures at 2-year follow-up,” said Dr. Wright.

Coauthors included Warren R. Dunn, MD, MPH; Annunziato Amendola, MD; Jack T. Andrish, MD; John A. Bergfeld, MD; David C. Flanigan, MD; Morgan H. Jones, MD; Christopher C. Kaeding, MD; Robert G. Marx, MD, MS; Matthew J. Matava, MD; Eric C. McCarty, MD; Richard D. Parker, MD; Armando F. Vidal, MD; Michelle Wolcott, MD; Brian R. Wolf, MD, MS; Kurt P. Spindler, MD.

Disclosure information on the authors can be found at www.aaos.org/disclosure