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舊 2008-09-13, 13:47   #1
eLeung
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Anterior Cruciate Ligament (ACL) Injury

The following article discusses what causes an ACL injury and how to prevent the injury in our skiing.

What is the ACL
The ACL, or anterior cruciate ligament, is a ligament located inside the knee joint. It is a major connector of the femur and the tibia and one of the key parts of the joint for maintaining a stable, yet flexible knee.

What Causes an ACL Injury
ACL injuries are caused by several factors. The most common is a traumatic force being applied to the knee in a twisting moment, causing forceful hyperextension. Skiers are particularly susceptible to these types of strains when landing jumps, skiing moguls or during twisting falls. The injury can also occur due to a contact force such as being hit from the front or side. Finally, ACL injuries can happen during a fall by a novice skier, when the bindings do not release.

Can I Prevent an ACL Injury?
There are several things you can do in the preseason and off season to decrease your risk of an ACL injury.

1) Do conditioning and strengthening exercises of the quadriceps and hamstring before ski season starts. This is the number one protection.
2) Ski easier at the end of the day, when you are typically fatigued. Avoid difficult trails, big air, lots of moguls, and speed skiing on ice. Take it easy in the late afternoon.
3) Do regular stretching exercises for the hamstrings, quadriceps, hip, back, shoulder. The more you stretch, the less likely you are to snap.
4) Use gear that is fit to you and is tuned up.
5) Check your bindings for release tension. Do not set them too tight!

Related link - http://sportsmedicine.about.com/cs/s.../aa020601a.htm
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舊 2008-09-13, 21:49   #2
Mike
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The ACL is one of the two cruciate ligaments that run through the centre of the knee. Together with the other ligaments it acts as a stabilizer for the knee, preventing the tibia (shinbone) from moving too far forward in relation to the femur when the knee is placed under increased forward stress.

Click the image to open in full size.

ACL tears are a common athletic injury, usually resulting from excessive pressure being placed on the ligament by a blow or twisting force.
Tears fall into three categories:
Grade 1 (mild) - a sprain with minimal damage to the ligament fibers and no noticeable laxity in the joint afterwards
Grade 2 (moderate) - an incomplete tear with some laxity in the joint
Grade 3 (severe) - a complete tear with significant laxity, often leading to an unstable or buckling knee

Since the ACL has no blood supply, so once it is torn it cannot repair itself.

More on this topic -
http://ehealthmd.com/content/what-an...ciate-ligament

此篇文章於 2012-07-06 07:00 被 Mike 編輯。. 原因: replace link
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舊 2008-09-13, 22:01   #3
ozman
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what are the major symptoms if one get ACL injury?

Will it cause permanent disability if not seeking medical treatment right away?
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舊 2008-09-13, 22:36   #4
carver_hk-ski
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作者: ozman 查看文章
what are the major symptoms if one get ACL injury?

Will it cause permanent disability if not seeking medical treatment right away?
If your muscle is strong you can still live like a normal person except that you cant run or pivot like a normal person. Eventually the soft tissue between the tibia & femur will get grind off at an abnormal rate compare with a normal person.
If you are not very strong then you can barely walk like a normal person. So no option.

i love line graphics
carver_hk-ski 目前離線   回覆時引用此篇文章
舊 2008-09-14, 09:16   #5
Mike
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This was previously posted in the old forum:

New research has shown that tears of the anterior cruciate ligament (ACL) in the knee are about twenty times more common in recreational Alpine skiers than in expert skiers.

US researchers pooled the results from 33 studies dealing with ACL tears. They looked at the injury in terms of sport, gender and training. They also found that ACL tears were more common in recreational skiers than in basketball, soccer and lacrosse players.

Interestingly, they found that the rate of tears was the same in male and female skiers, which is unusual. Most research has found the injury is generally more common in women.

Citation: Prodromos CC et al. A meta-analysis of the incidence of anterior cruciate ligament tears as a function of gender, sport, and a knee injury-reduction regimen. Arthroscopy 2007; 23: 1320-5.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

A BBC report today has also highlighted the risk of skiing and knee injuries. Steve Bollen, president of the British Orthopaedic Sports Trauma Association, has claimed that a boom in short skiing holidays abroad is leading to a rapid increase in knee injuries. He blames poor fitness among beginners, describing many of the serious ligament injuries he sees as "half-term syndrome".

Mr Bollen, an orthopaedic surgeon at Bradford Royal Infirmary, has conducted a study of more than 200 patients with ACL or medial ligament injuries in his clinic. He found that, while rugby and football were still the biggest culprits, the percentage of such injuries linked to skiing had soared to 28% in 2004. More than nine out of ten of the injured skiers were women.

Damage to the ligaments which hold the knee together can require surgery to repair, and if left untreated, can cause irrepairable damage to the joint.

However, this is one of the most common injuries caused by falls or twisting during skiing, partly due to the design of modern ski boots, said Mr Bollen.
"If, when you fall, the ski bindings do not release, the rigid, high boots mean that all that force can go straight through the knee, which can be very damaging."

Background information
The anterior cruciate ligament is in the centre of the knee joint and controls rotation. It is, therefore, vulnerable to excessive twisting movements. It can also be injured when there is a large sideways movements of the joint. Such movements will initially injure the ligaments on the inside (medial collateral ligament, MCL) or outside (lateral collateral ligament, LCL) of the joint but, as the joint opens out excessively, the ACL can also be torn.

Not surprisingly, the common sports that produce this injury are football, rugby, skiing, basketball and netball. Women are generally at greater risk than men; the cause for this is not completely understood, but it may be due to differences in anatomy and muscular function.

Typically, when the ACL is ruptured, there is a feeling or hearing of a pop or snap, or something tearing when the knee undergoes a twisting movement while running or landing from a jump, or if there is a blow from the side of the knee. It is not usually possible to carry on after the injury, and if it is, the knee will soon collapse. The knee then swells within 4 hours. The swelling then takes a couple of weeks to settle and a return to activity is possible, but only in straight lines. If an attempt to change direction at speed is made, the knee feels as if it comes apart.

Damage to the ligaments that hold the knee together can require surgery to repair, and if left untreated, can cause irreparable damage to the joint.
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舊 2008-09-15, 01:56   #6
jackwan
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Well, if you sever your ACL, you will tell... You cannot even move, and yes, you will have permanent injury if no operation is done...:(

most of the ACL injury we have are partially torn and bruised ACL, that may or may not be healling by itself, you need to see a doctor.
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舊 2008-09-18, 14:30   #7
eLeung
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Whether it is a big surgery operation? How long one can recover after the operation?
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舊 2008-09-18, 15:20   #8
carver_hk-ski
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most of the ACL injury we have are partially torn and bruised ACL, that may or may not be healling by itself, you need to see a doctor.
This is not true. ACL won't heal itself as a result of lack of sufficient blood flow. It probably the surrounding muscles get stronger as a result of weaker ACL that make people think it healed itself.

It is not a small operation. Recovery after surgury involve months of rehab programme to follow. Some people can return to sport in 3 months some takes longer. The norm is probably 6 months for skiing.

So, becareful all skiers. No skier can escape the risk. But many people said the more skillful the safer. :)

Here is a good webpage.
http://www.financeprofessor.com/funl...clsurgery.html

i love line graphics

此篇文章於 2008-09-18 16:25 被 carver_hk-ski 編輯。.
carver_hk-ski 目前離線   回覆時引用此篇文章
舊 2008-09-18, 16:36   #9
hy
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Very good info.. Just wish we all be prepared and play safe.
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舊 2010-04-06, 19:24   #10
Mike
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Here is a video clip of an accident showing how it happened.

A skier sustained an ACL rupture of the left knee after a small jump that went wrong, resulting in falling backwards. It all happened quickly , although you'll notice that she was not travelling that particularly fast.
Watch the uphill ski un-weight, the hips go below the knees, the skier's body faces down the slope. You can actually hear her reaction (a loud "Uuh") at the moment the ACL pops.

Mike 目前離線   回覆時引用此篇文章
舊 2010-04-07, 10:21   #11
hy
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After I read this in 2008. I hurt my knee in 2009 during a very slow speed turn. I could not stand right after the fall and was carried down the hill. Stayed in wheel chair for 2 days, skied on one foot for another day, then shopping for another day before returning home.

Did MRI, the analyst said the ACL was totally torn. The specialist said it was not because the range of movement, the strength and other physical examination of my knee indicated injured MCL rather than ACL. Besides, I did not hear the "pop" sound during my fall and the initial examination in ski site also indicated MCL. Sought second opinion from another specialist, he said ACL injury. Operation cost around HKD120,000-150,000.

The only sure way to check whether it was ACL injury was to operate. Open up, no injury, close up. HKD50,000. Open up, injury, operate, HKD120,000.

Checked with physio, it did not look like ACL but of course specialist was the best guy to tell. Even it was ACL, not necessary operation. Some guys broke their ACL even without knowledge, especially for young kids. They developed stronger muscle to compensate injuried ACL. After ACL operation, he recommended 9 months rehab program. Just in time for the next skiing season.

Despite the costs and long rehab program, there are also risks in ACL operation....

So, I went with no operation. Skied in 2010, gentlely and shorter ski. Felt okay. Will check again next year....

My lessons? Ski safe, get insurance and make sure the coverage is high enough....just in case.
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舊 2010-04-07, 10:53   #12
Mike
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hy, glad to hear that you are recovering and able to enjoy skiing once again.

ACL injury is one of the most feared injuries to skiers ( fortunately, not the most common), as to what cause ACL injury, here below is an article on the causes :

http://www.ehealthmd.com/library/acl...CL_causes.html

http://www.ehealthmd.com/library/acl...cl_whatis.html

As to whether ACL requires surgery, one study said,
I quote: "ACL tears do not necessarily require surgery. There are several important factors to consider befoe undergoing ACL surgery. First, do you regularly perform activities that normally require a functional ACL? Second, do you experience knee instability? If you don't do sports that require an ACL, and you don't have an unstable knee, then you may not need ACL surgery.

The is also a debate about how to treat a partial ACL tear. If the ACL is not completely torn, then ACL reconstruction surgery may not be necessary.

Many patients with an ACL tear start to feel better within a few weeks of the injury. These individuals may feel as though their knee is normal again, but the problems with instability may persist."

As with regard to the surgery, The report further stated that the usual surgery for an ACL tear is called an ACL reconstruction. A repair of the ligament is rarely a possibility, and thus the ligament is reconstructed using another tendon or ligament to substitute for the torn ligament.
The are several options for how to perform ACL surgery. The most significant choice is the type of graft used to reconstruct the torn ACL. There are also variations in the procedure, such as the new 'double-bundle' ACL reconstruction.
Risks of ACL surgery include infection, persistent instability and pain, stiffness, and difficulty returning to your previous level of activity. The good news is that better than 90% of patients have no complications with ACL surgery.

Yes, insurance is highly advisable. Let's hope we never have to make any claim.
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舊 2010-04-07, 15:13   #13
hy
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Mike, thanks. I am a bit lucky in my situation.
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舊 2010-04-08, 17:52   #14
Mike
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Informative articles on ski injuries:

http://www.ski-injury.com/specific-sports/alpine

http://www.physioroom.com/sports/ski...injuries_2.php
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舊 2010-04-27, 20:10   #15
Mike
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Having read the articles on the cause of ACL injury, it appears that "rearward twisting fall" is the type of fall that predominantly threatens your ACL (see the video in posting #10)

In a rearward twisting fall situation, your weight is on your heels throughout the entire fall. That is where the trouble is - the heel. It takes very little force to bust your ACL.
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