Arthroscopy: The Journal of Arthroscopic and Related Surgery 8(1):19-22 Published by Raven Press, Ltd. 0 1992 Arthroscopy Association of North America
What Is the Terrible Triad? F. Alan Barber, M.D., F.A.C.S.
Summary: In 1936 Campbell asserted that “impairment
of the anterior crucial and mesial ligaments is associated with injuries of the internal cartilage.” O’Donoghue in 1950 called attention to “that unhappy triad (1) rupture of the medial collateral ligament, (2) damage to the medial meniscus, and (3) rupture of the anterior cruciate ligament” and recommended early surgical intervention. In 1955 he reported 33 cases with both medial collateral (MCL) and anterior cruciate ligament (ACL) tears, but there were only three lateral meniscus tears reported. Based on a recent report by Shelbourne and Nitz that questions the validity of this unhappy triad, a review of all arthroscopically confirmed acute injuries of second degree or worse to the ACL and MCL was undertaken. Of a total of 52 knees reviewed, 50 knees had third-degree ACL tears and two had second-degree ACL tears. One of the second-degree tears was associated with a second-degree MCL and one with a third-degree MCL tear. Neither had an associated meniscus tear. Forty-five third-degree ACL tears were associated with third-degree MCL tears (group 1) and five with second-degree MCL tears (group 2). Eighty percent (36 knees) of group 1 had lateral meniscus tears. Only 29% of group 1 (13 knees) had associated medial meniscus tears. None of these medial meniscus tears was isolated. Eighty percent (four knees) of group 2 had lateral meniscus tears with only one associated medial meniscus tear. Again, there were no medial meniscus tears in the absence of a lateral meniscus tear. We did not find the combination of injury originally described as the unhappy triad. Key Words: Terrible triad-Anterior cruciate ligament-Medial collateral ligament-Lateral meniscus.
In 1936 Campbell asserted that “impairment of the anterior crucial and mesial ligaments is associated with injuries of the internal cartilage” (1). He later stated that “these ligaments are commonly ruptured by the same mechanism which injures the medial cartilage . . .” (2). O’Donoghue in 1950 called attention to “that unhappy triad (1) rupture of the medial collateral ligament, (2) damage to the medial meniscus, and (3) rupture of the anterior cruciate ligament” and recommended early surgical intervention (3). In 1955 he reported 82 major ligament operations, which represented his G-year surgical experience (4). Thirty-three of these 82 (40%)
were for tears of at least the medial collateral (MCL) and anterior cruciate ligaments (ACL). He reported 24 cases with MCL, ACL, and medial meniscus tears; another three cases with the PCL injured as well; three cases with only the MCL and ACL torn; and three cases with MCL, ACL, and both medial and lateral meniscus torn. Of these 33 knee with MCL and ACL tears, there were only three lateral meniscus tears, all associated with medial meniscus tears. Recent reports continue to refer to this combination of injuries as a specific clinical entity (5,6). A recent study by Shelbourne and Nitz has raised the question that the unhappy triad may not occur with the frequency suggested by O’Donoghue (7). To evaluate this premise, a retrospective review of all arthroscopically confirmed acute injuries of seconddegree or worse to the ACL and MCL was undertaken.
From the Division of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, and Plano Orthopedic and Sports Medicine Center, Plano, Texas, U.S.A. Address correspondence and reprint requests to Dr. F. Alan Barber, Plan0 Orthopedic and Sports Medicine Center, 3801 W. 15th Street, Bldg. 2, Suite 250, Plano, TX 75075, U.S.A.
F. A. BARBER METHODS AND MATERIALS
Fifty-two knees with arthroscopically confirmed acute (