[Fractures of the lower extremity in skiing - the influence of ski boots and injury pattern].
BACKGROUND
Though the injury patterns of the lower extremities in skiing have changed since 1970, tibial fractures remain daily work of hospitals near ski slopes. A lot of medical studies have analysed the relevance of well adjusted bindings of the common lesions of the knee joint ligaments. However the influence of the flexibility of the ski boot and the injury pattern has been neglected.


METHODS
49 tibial fractures have been analysed in a hospital near a large ski resort in the alpes. All fractures occurred during alpine skiing. The type of the fracture, according to the AO-classification and the injury pattern have been documented. Also demographic data, ski experience and specification concerning the ski boot have been questioned. The type of the ski boot and the grade of flexibility, have been documented if possible. It has also been recorded whether the binding opened.


RESULTS
In contrast to other studies our patients are represented in widely spread age-groups with a large share of elderly and experienced persons. Young or unexperienced sportsmen suffer primarily from fractures of the tibial diaphysis. With increasing skiing experience the injury pattern is widening on the whole leg. 62 % of all fractures are caused by rotation traumas. Compression, dorsal forces and direct collisions are the other causes. In 59 % of all accidents the binding failed to open. There is an increased risk of complex fractures in the proximal or distal epiphysis if the binding has not opened. 23 % of all fractures occurred with rented ski boots. Only 16 % of all ski boots are labelled with a flexibility index. There is no standardized value for the flexibility of ski boots. The trend can be derived that rigid ski boots with a high flexibility index cause above all fractures of the diaphysis. 10 % of all fractures happened to patients wearing "snowblades". These short skis without safety bindings contributed a considerable share to tibial fractures, even though there is no big leverage.


CONCLUSIONS
Tibial fractures are still a frequent injury in alpine skiing. Increasing dynamics by means of improved material lead to enlarged forces on the lower extremity. Rotation forces are the major cause of tibial fractures. Therefore it is necessary to adjust the binding to the weight and abilities of the athlete. Also the appropriate choice of the right ski boot is essential. We recommend an internationally standardized marking regarding the flexibility of ski boots to enable the customers to compare the ski boots.
Bürkner
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Chirurgische Klinik, Spital Limmattal, Urdorferstrasse 100, 8952 Schlieren, Schweiz. andreas.buerkner@spitallimmattal
Simmen
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D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012399:Rotation; D012775:Shoes; D012865:Skiing / Q000293:injuries* / Q000502:physiology; D013978:Tibial Fractures / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control