The most important three-point play of Purdue senior Robbie Hummel's career might have come on Nov. 1, when he sank a layup while being knocked to the hardwood. Never mind that it was an exhibition game against outclassed Northern State, a Division II school. It was the first time the sweet-shooting senior forward had played in a game since Feb. 24, 2010, when he tore the ACL in his right knee on a routine drive against Minnesota. Hummel rehabbed that injury in time to start preseason practice last year, only to come down awkwardly after blocking a shot in practice on Oct. 16 and tear the ACL again. "I went through the typical, Why me? type of stuff," Hummel says.
But then he got to work, this time taking eight months rather than six to recover and spending more time in the gym strengthening his quads, hamstrings and glutes to help stabilize his knee. Against Northern State, Hummel was knocked to the floor on both of his first two scoring plays but popped right up both times. "It's scary, because last time I hit the floor like that it wasn't a good outcome," says Hummel, who was leading the 6--1 Boilermakers with 19.3 points and 4.9 rebounds per game at week's end. "But every time it happens I gain confidence."
And Hummel should be confident. Unlike decades past, an ACL tear is no longer a career-deadening injury. Doctors now take a graft from the patellar tendon or hamstring to repair the ACL (see diagram, above), and the tunnels of the knee joint are so well understood that a modern ACL repair now nearly restores the native architecture of the joint.
Still, there is evidence that Hummel will be at increased risk of a third tear. According to Rick W. Wright, professor of orthopedic surgery at Washington University in St. Louis, about 5% of young patients whose ACLs are repaired with their own tissue will tear those ligaments a second time within two years, and around 13% who have torn the same ACL twice—like Hummel—will tear it a third time. Why some people appear prone to repeated ACL tears is the subject of many hypotheses and of Wright's ongoing MARS project (Multicenter ACL Revision Study). Even with Hummel's heightened risk, though, says Wright, "The odds are much higher that [Hummel] won't tear it again."