Polamalu's Knee Injury May Keep Him Sidelined For Longer Than Expected

Polamalu's Knee Injury:

In the second quarter of Pittsburgh's win over Tennessee last night, Troy Polamalu was attempting to recover the football when Alge Crumpler rolled onto his L lateral knee.

Polamalu came off the field and did not return to the game. The diagnosis was an MCL (medial collateral ligament) sprain, but in watching footage of the injury, my guess is that it is not isolated to the MCL.

The MCL is the medial (inner) stabilizing ligament of the knee joint, and it spans from its origin on the femur (thigh bone) to its insertion on the medial tibia. When a player receives a lateral (valgus) stress to the knee joint, with the foot planted in the turf, the MCL is stretched and many of the fibers can be torn. This is similar to what happens to the Anterior Talofibular Ligament when the ankle is sprained.

Ligament sprains are graded as I, II, and III according to their severity. Grade I sprains have mostly intact ligament with only some minor tearing of the fibers. Grade II involves approximately half of the fibers being torn and the knee being unstable when a valgus force is applied. Finally, Grade III injuries involve the majority of ligament fibers to be torn and the knee to be unstable medially.

From evaluating the mechanism of the injury, this is most definitely a grade II injury and could very well be a grade II-III injury. The natural history of this injury, like all ligament sprains, is that the body's inflammatory response eventually scars over the torn fibers of the ligament and with time new fibers are generated.

If it is an isolated MCL injury, players can return to play as early as four weeks, but unfortunately they would be at best 80 percent of their previous level of functioning. It takes a good three months of diligent rehab to really approximate how the athlete was before the injury.

Unfortunately, this is not the only problem. Players like Polamalu, who rely on cutting and pivoting, and a quick change of direction—all things that the knees collateral ligaments are relied heavily upon—would probably not return to 90 percent of previous functioning until about four months of physical therapy.

Finally, when reviewing the videotape it appears that there was also a rotatory or pivoting motion of the knee as Crumpler fell on the lateral side. This makes me believe that Polamalu also has a small tear in his medial meniscus—one of the cushioning cartilage pieces of the medial knee. If this is true—and this is only speculation—as many MCL injuries involve tearing of the medial meniscus, and sometimes a disruption of the ACL. This means that Polamalu's rehab could take even longer, and he may not be a factor until late in the season.

Athletes with an isolated medial meniscal tear often have a debridement—or clean-out procedure—to arthroscopically remove areas of fraying or slightly torn meniscus. This allows return to play as quickly as 4-6 weeks; however, with a grade II MCL also involved, a viable return to play would not happen for at least eight weeks.

Lastly, Polamalu may return to play at some point this season, but I would bet that he will have arthroscopic surgery in the off-season to smooth out the meniscus and possibly tighten the fibers of the MCL.

Given that Polamalu is such an integral part of the Steelers' coverage and blitz packages, they will have to go at least 2 months without their star player contributing any valuable minutes on the field.

David Webner, MD

Co-Director, Sports Medicine Fellowship

Crozer-Keystone Health System

Suburban Philadelphia, PA