Yudu - sportEX medicine - 1999-2010

KNEE INJURY DIAGNOSIS

calf which drives the tibia out from under the femur and the ACL tears.

A third mechanism is now recognised whereby a stationary skier is hit from behind on the lower leg (often by a snow- boarder) – this again applies sudden extreme pressure on the back of the calf, forcing the tibia forwards with resultant ACL damage. Presentation/diagnosis: Often the indi- vidual describes feeling or hearing a ‘pop’ or a ‘snap’, with the knee ‘giving way’ beneath. A haemarthrosis usually devel- ops within one hour of injury. Investigation: Both the anterior drawer and pivot shift test are useful for investi- gating ACL integrity (see p9). MRI scan- ning/plain radiographs to detect associat- ed bony, soft tissue damage and improve diagnostic pick up Treatment: Controversial! In the UK, the general trend is to aspirate the haemarthrosis and initially treat conserv- atively with splinting and intensive phys- iotherapy aiming to build up muscle strength to help stabilise the joint. In the US and Europe, early arthroscopy ligament repair and mobility is advocated Prevention: Education to recognise potentially dangerous situations occur- ring. In general, always aim to keep arms forward, feet together and hands over skis

AVOIDING HIGH RISK

ACL BEHAVIOUR ● Don’t fully straighten your legs when you fall. Keep your knees flexed

● Don’t try to get up until you’ve stopped sliding. When you’re down – stay down

● Don’t land on your hand. Keep your arms up and forward

● Don’t jump unless you know where and how to land

● Land on both skis and keep your knees flexed

3. TIBIAL PLATEAU FRACTURES Incidence: Approximately 1% of all ski injuries. Usually affect older, more experi- enced skiers Cause: Severe valgus stress often with compressive forces eg. as the result of a bad landing after a jump Presentation: Haemarthrosis usual. There may be bruising and/or abrasions over the lateral aspect of the joint and an associ- ated valgus deformity of the knee

12 SportEX Medial meniscus Lateral meniscus Tibia

Medial collateral ligament

Investigation: Usually evident on plain radiographs. CT scanning might be required to determine the exact degree of displacement and area of articular surface involved Treatment: If the fracture is displaced or depressed by more than 4mm then surgery is advised to restore anatomical align- ment. Frequently these injuries occur at high speed and there is associated severe damage to other soft tissue structures – particularly the ACL and MCL – which will require surgical intervention Prevention: Avoiding high jumps and the consequential high compressive forces

4. MENISCAL INJURY Incidence: Occurs in approximately 5 –10% of all ski injuries, often in associa- tion with damage to another structure. Usually affects the lateral meniscus due to a valgus twist in a weight bearing knee Cause: Rotational stress applied to a flexed, weight bearing knee. Usually the result of catching an edge at speed Presentation/diagnosis: Considerable pain and difficulty weight bearing but may have little swelling. Joint line ten- derness is usually evident, especially in the last few degrees of full knee exten- sion. May present with a ‘locked knee’, where a torn mensical fragment physically prevents full extension of the joint. Tests for meniscal tears include McMurray’s test (see p9) and Apley’s compression test although the latter is no longer thought to be a reliable test Investigation: Imaging may be necessary

Femur

Anterior cruciate ligament

Posterior cruciate ligament

Lateral collateral ligament

to exclude associated injuries Treatment: A locked knee requires early arthroscopy and repair. Other isolated tears can be managed expectantly with conservative treatment

References and further reading 1. Paletta GA and Warren RF. Knee Injuries and Alpine Skiing: Treatment and Rehabilitation. Sports Medicine 1994;17(6):411-423 2. Ettlinger CF, Johnson RJ and Shealy JE. A Method to Help Reduce the Risk of Serious Knee Sprains Incurred in Alpine Skiing. Am J Sports Med 1995;23(5):531-537 3. Langran M, Jachacy GB and MacNeill A. Ski Injuries in Scotland: A Review of Statistics from Cairngorm Ski Area, Winter 1993/4 Scottish Medical Journal 1994;41(6):169-172 4. Johnson RJ and Ettlinger CF. Alpine Ski Injuries: Changes through the years. Clin Sports Med 1982;1(2):181-197 5. Mona D. ACL Reconstruction and Rehabilitation: A protocol of accelerated reha- bilitation. Department of Sports Trauma, Lugano, Switzerland. Presented at 13th International Congress on Ski Trauma and Skiing Safety, Cervinia, Italy. May 1999 6. Johnson RJ, Ettlinger CF, Shealy JE and Meader C. Impact of super sidecut skis on the epidemiology of skiing injuries. Sportsverl. Sportschad 1997;11:150-152

Further resources ● www.nsaa.com - very useful free booklet in PDF format ● www.ski-injury.com - more info from Dr Langran’s team on snow injuries

Dr Mike Langran is a GP in Aviemore, Scotland and a member of the International Society for Skiing Safety. He is an executive commit- tee member of the British Association of Ski Patrollers and director of the Scottish Ski and Snowboard Injury database study.

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