Fractures were once a fact of life for downhill skiers. The fractures most frequently occurred in the lower leg or in the tibial plateau -- the top of the shin bone just below the kneecap. The advent of the releasable ski binding, along with higher and stiffer ski boots, reduced the incidence of fractures, but ligament injuries are still common. Cross-country skiers are not immune to knee problems but suffer from a different type of injury.
Why Injuries Happen
Numerous factors increase your susceptibility to on-slope knee injuries. The main culprits include poor technique; skiing on terrain above your skill level; improper equipment for your height, weight and proficiency; and unsuitable release settings on your ski bindings. Slope conditions also play an important role in the potential for injury. Falling on ice causes more damage than falling on deep, fluffy powder, while ungroomed slopes or trails, which may have unexpected bumps, challenge your balance. Skiing in late afternoon can add to the peril; when the clouds roll in, they cause a phenomenon called flat light, which reduces visibility and contrast, making it difficult to see sudden changes in the terrain.
Fractures
If your binding does not release during a fall, the weight of your ski overpowers the integrity of your bones, making them susceptible to fracture. The tibial plateau is the most common fracture site, but fractures account for only 1 percent of skiing injuries, reports Ski-injury.com. Fractures primarily occur in unique circumstances such as jumping off cliffs and landing improperly. Bruising, abrasions and knee deformity may indicate a tibial plateau fracture.
Nordic Ski Injuries
While cross-country skiers may incur fractures and ligament tears, the endurance requirements of the sport are more apt to cause overuse injuries. Patellofemoral pain syndrome, also called chrondromalacia of the patella, is an example. Cross-country skiers experience this condition as a dull, throbbing pain in the front of the kneecap. Unlike other knee injuries, chrondromalacia of the patella generally does not cause inflammation, Dr. Stacie Lynn Grossfeld told "Cross Country Skier Magazine." Knock-kneed skiers and people with flat feet are most susceptible.
Alpine Ski Injuries -- MCL Tear
The medial collateral ligament, or MCL, is located in the inner part of the knee and connects the inner thigh bone to the inner shin bone. MCL tears and sprains are common among novice skiers. The wedge or snowplow position, in which the skier locks his knees and shifts his weight to his inner knee joint, may be responsible, says Dr. Edward Staub, an orthopedist and clinical instructor at Yale University. Falling while in the wedge position can strain, sprain or tear the MCL. Most sprains and strains heal on their own and do not require surgery. Lateral collateral injuries occur when the skier catches the outer edge of his ski on the snow. He falls sideways, locking and twisting his leg, and causing a tear or strain in the outer knee ligament.
Alpine Ski Injuries -- ACL Tear
Tears of the anterior cruciate ligament, or ACL, account for 30 to 40 percent of all alpine ski injuries, according to orthopedist Dr. Mike Langran of Ski-injury.com. The ACL's primary function is to prevent twisting of the knee. Tearing of the ACL most often occurs when the skier falls backward while his kneecap twists toward the center of his body. An MCL tear often accompanies an ACL injury. An ACL tear often is technique-related, says Dr. Carl Ettlinger, of the Vermont Ski Safety report. It typically occurs in skiers who keep their weight on the tails of their skis and their arms and poles behind the body.
References
- Ski-injury.com; Knee Injuries; October 2010
- DrStaub.com; Ski Injuries; Edward Staub, M.D.
- American Orthopaedic Society for Sports Medicine; Alpine Skiing and Snowboarding Injuries; 2008
- Vermont Ski Safety: Tips for Knee-Friendly Skiing
- Cross Country Skier; A Body in Motion; Stacie Lynn Grossfeld, M.D.
