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Knee Injuries
Incidence: The commonest alpine ski injury, accounting for 20-25% of all injuries. Most commonly affects beginner and low-intermediate skiers.
Cause: Affected individuals are usually in the “snowplough” position with the knee joint in a valgus position (lower leg leaning out the way relative to the thigh). Injury results from excessive valgus force being applied to the knee joint, either as the result of a fall, the skis crossing, or the snowplough stance widening. In more proficient skiers, usually occurs as a result of unexpectedly “catching an edge” which unexpectedly throws the ski (and thus the lower leg attached to it) outwards.
Presentation/diagnosis: The diagnosis is usually suggested by the description of the fall. Examination reveals tenderness over the medial collateral ligament and pain on weight bearing. The presence of a haemarthrosis suggests a third degree tear, associated damage to the ACL and/or injury to the bony structures of the knee.
Assessment: In the acute phase, pain usually precludes accurate assessment of ligament stability. When possible, this should be performed by applying valgus stress with the knee in 30 o of flexion and the foot in internal rotation (see diagram below left).
Investigation: Often not needed, but radiographs will identify associated bony injuries whilst MRI will detect other soft tissue damage (e.g. to the ACL/meniscus)
Treatment: Grade one and two sprains should be placed in an extension splint until pain and swelling subside. Grade three tears may require surgical repair or the application of a plaster cylinder.
Prevention: Pre- season quads conditioning, correct binding maintenance and release settings. Avoiding wide snow plough stances which are inherently unstable. Beginners are advised to allow a fall to occur rather than attempting to resist which in turn may lead to more damage.
Head Injuries and Helmet
So what about helmets reducing the rates and severity of head injuries?
Again, things have to be kept in perspective. Head injuries account for at most 10-15% of these although some studies have shown higher rates in children (up to 43% in one Canadian study though I have not seen that reported anywhere else). But even taking this 43% rate coupled with the highest injury rate gives a rate for head injury of 2.4 per 1000 skier days - really very low. a more average risk would be about 0.3-0.5 per 1000 skier days. Most of these injuries are minor (usually concussion) and as I have already mentioned the bad ones are usually the result of skiing or boarding out of control.
Nakaguchi et al last year published a two year prospective study of snowboarding head injuries from Nagano, Japan. The overall rates for head injury were 6.5 per 100,000 visits for snowboarders and 3.8 for skiers. Out of a total of 301 cases, 11 (9 boarders and 2 skiers) were classified as “major”, three of whom required neurosurgery and were left with residual neurological deficit.
Such occurrences have fortunately been extremely rare in Scotland, although its no reason for complacency. Last year’s three centre study revealed that head injuries accounted for 64 of the 732 (8.7%) injuries seen with an absolute rate of 0.32 per 1000 skier days. Out of this total, two thirds involved skiers and one third boarders. A quarter were caused by individuals being hit by lift bars. 6 people were kept in hospital overnight but all recovered without major dramas.
So the real issue is that of risk calculation - i.e. how likely is a head injury to occur? It would appear to be actually very low. This is the precise reason that cycle helmets have not been made compulsory in the UK - yes, they may reduce injuries but the absolute risk of getting one in the first place is relatively small and not great enough to warrant a mandatory law.
There is nevertheless a strong argument that any degree of risk that can be reduced, should be reduced. As a result, more and more skiers and snowboarders are buying helmets every year. Helmet sales in the US are increasing year by year and the same trend is likely to start being seen here. It seems as if my prophesy has finally come true... where not so long ago helmets were viewed as uncool, the opposite is now increasingly true - wear a helmet and you are a dude!
Wrist Injury
Many studies have now demonstrated that snowboarding has a distinctly different pattern of injuries to alpine skiing - both in terms of the areas of the body that get injured and the types of injury sustained. Compared to skiers, snowboarders are far more likely to sustain an injury to the upper limb and less likely to injure the lower limb. The incidence of fractures (broken bones) is twice as high amongst snowboarders compared to skiers - (approximately 25% of all injuries in boarders are fractures compared to 12.5% in skiers). The reasons for these differences can be explained by the design of the equipment and the way it is used. When travelling on piste, snowboarders ride with both feet fixed firmly to the snowboard in non release bindings. The upper body is used to help generate turning forces on the board. In the event of a loss of balance and a subsequent fall, the instinctive reaction of a snowboarder is to outstretch a hand in order to try and break their fall. This mechanism is known as a 'FOOSH' amongst emergency department staff (standing for Fall Onto an Out Stretched Hand). As a result, the wrist is the single commonest site of injury amongst snowboarders - an area that is rarely injured whilst alpine skiing. It is important though - sustain a broken wrist and you won't be snowboarding for at least 6-8 weeks, if not longer (unless you're a real loon....)
Shoulder Injuries
Shoulder joint injuries can develop either acutely (e.g. a sudden fall) or chronically (e.g repetitive strain). On this page I am going to be concentrating on the common acute problems that affect the shoulder joint as a result of snow sports accidents. This is not meant to be an in-depth appraisal of orthopaedic treatments, but a simplified description of injuries and treatment. For more general information on the shoulder joint itself, try the American Academy of Orthopaedic Surgeons webpage - here.Not surprisingly, the two commonest mechanisms leading to shoulder injuries on the slopes are falls and collisions. Falls can injure the shoulder in one of three ways -
- The casualty falls directly onto the shoulder joint itself
- In the process of a fall, the casualty lands onto an outstretched hand and the force of the fall is transmitted up the arm to the shoulder joint
- The casualty again falls onto an outstretched hand, but also in the event of the fall the casualty's body twists around the outstretched hand which applies a twisting force up to the shoulder joint
In common with all other snow sports injuries, its the mechanism of the injury, coupled to the force(s) involved and the time frame over which they are applied, that dictates the type and severity of the resultant injury.
Spinal Injuries
Spinal injuries are a rare but potentially devastating consequence of participation in many activities - snow sports included. Whilst one must never forget to manage life threatening airway, breathing and/or circulation problems first, the important thing with spinal injuries is to always consider whether the spine may have been damaged and - if it possibly has - treat the casualty appropriately to prevent any further injury.
Types of Spinal Injuries
The easiest way to visualise spinal injuries is to think of the spinal column as a series of bricks, one on top of another with a wee soft disc in between each block (representing the discs). In the middle of each block and disc is a central hole, 
through which the spinal cord passes. The discs, being soft, allow the spine to be flexible so it can bend forwards (flexion), backwards (extension) and side wards (lateral flexion) as well as twist from side to side (rotation). The bricks also vary in strength - those in the cervical spine are small and relatively delicate - so less force is needed to break them. The lumbar bones, which need to support more of the body's weight, are big and strong and a lot of force is needed to damage them. The thoracic bones are in the middle - the lower ones are tougher than the upper ones.
The two main mechanisms of injury seen on the slopes are
- Flexion/hyper-extension - where the head bends forwards and then extends back (like whiplash)
- Compression - where the bones are pushed down onto one another