Anterior Cruciate Ligments (ACLs)

With the winter Olympics almost finished, we've been hearing about anterior cruciate ligment (ACLs) injuries every day, so I thought it timely to discuss this in a bit more detail.

The ACL originates on the anterior intercondylar area of the tibia and inserts on the posteromedial aspect of the lateral femoral condyle.  It is composed of two bundles of type 1 collagen fibres; an anteromedial bundle (taught in flexion) and a posterolateral bundle (taught in extension).  The ACL is the primary restraint to anterior translation of the tibia relative to the femur.  It plays a secondary role in restraining internal rotation particularly when the knee is close to full extension.     

A number of risk factors have been associated with ACL injuries.  They can be divided into 4 categories:

Anatomical

-          Increased BMI

-          Narrow femoral notch width

-          Greater ligament laxity

-          Wider pelvis and Q angle

Hormonal

-          Oestrogen levels during early and late follicular phase of menstrual cycle

Environmental

-          Harder surfaces

-          Increased shoe-surface friction

-          Cleat position

Neuromuscular 

-          Poor ability to control dynamic knee valgus

-          Quads/hamstring ratio

-          Reduced knee and knee flexion angles

Previous ACL injury is also a risk factor for ACL injury for both the reconstructed or contralateral knee (Orchard et al 2001).

Approximately 70% of ACL injuries are non-contact injuries, usually seen in sports and activities involving complex movements such as cutting and pivoting account (e.g. netball, football) (Hernandez, 2006).  A non-contact ACL rupture usually involves a rotational or lateral valgus force on the knee with the knee flexed and the foot planted.  An example of this is the football player who steps off his foot in a cutting manoeuvre to try and change direction, only to have his knee buckle underneath him   http://www.youtube.com/watch?v=lpIOMuqXWrE Contact ACL injuries often occur from hyperextenion or valgus forces applied externally to the knee (e.g. contact from an opponent).

Patients often report hearing a ‘pop’ as the ACL ruptures.  Gross swelling of the knee and spasm of the hamstrings usually occurs within minutes.  Standard assessment involves a stress test for the ACL – these include Lachman’s, pivot shift and anterior drawer.  Unless performed soon after injury, hamstring spasm can limit the effectiveness of these tests.  Patients report pain with knee movement, decreased ROM and instability of their knee.   MRI is the current gold standard for diagnostic imaging.  This is also useful to investigate other pathology that may be present such as medial meniscus injury or MCL tear (unhappy triad).  Whether you can have a partial tear of the ACL also remains debatable.    

 

 

Pictures from: http://www.emedx.com/emedx/diagnosis_information/knee_disorders/acl_mri_pictures.htm

ACL tears do not heal after injury.  Stitching the ligament back together has generally failed due to a poor blood supply and poor healing environment created by the synovial fluid.  As a result, ACL injuries are costly in a number of ways: time lost from sport, financial costs of rehab and/or surgical repair, long term consequences such as osteoarthritis, and decreased quality of life.  

Which brings up the questions: Can you function without an ACL and what are the consequences of doing so?

We know the ACL helps with dynamic stability of the knee so without an ACL the stability of the knee is compromised which potentially MAY cause further damage such as meniscus tears.  However in some patients, this can be compensated for with good neuromuscular control.

Eitzen et al (2010) recommend a period of rehab (prehab) to inform decision making for the management of ACL injury (ie conservative vs surgical).  And what a great idea that is (no sarcasm intended)!  As a sports physio I often see patients with ACL tears who almost immediately see a surgeon who operates within days to weeks without any form of prehab.  I don’t think this is ideal for a number of reasons including: a) some patients can function without an ACL, b) prehab results in better outcomes post-surgery and c) patients can have a false sense of security that after surgery their knee will be just like new. 

Prehab according to Eitzen’s (2010) study should start when initial impairments have resolved (no joint effusion, no gait abnormalities, equal ROM, able to hop pain free).  Whether this is suitable criteria remains to be tested.  I would think if you can hop pain free you’re doing ok.  Initial testing involved 4 single leg hop tests, self-reported questionnaires, global rating of knee function, episodes of giving way and isokinetic quads and hammy strength tests.  Eitzen’s prehab program then involved progressive exercise therapy for 5 weeks (for patients playing level 1 and 2 sports – see table below) followed by retesting.    Results from this study found a significant improvement in knee function in patients with ACL injury suggesting a period of prehab is important prior to surgery or as the beginning of a progressive conservative rehab program. 

Activity Level & Skill Requirements

Level	Skills	Example Sports
1	Jumping, Cutting, Pivoting	Soccer, Netball, Football, Basketball
2	Lateral Movement OR Heavy manual labour OR working on uneven surfaces	Tennis, Skiing
3	Light activity	Running, weight lifting
4	Sedentary activity	Housework, ADLs

 

Frobell et al (2010, 2013) have shown that delaying reconstruction does not affect outcomes.  Two year and 5 year data show patients (active, but not elite athletes) who had early reconstruction (<10wks) did not have better self-reported outcomes (KOOS) than those who had delayed reconstructions (>5-19mths).  As physiotherapists we should be encouraging a period of prehab prior to any surgery.  This will always be influenced by the athlete, level of sport they play, demands of other parties (club, coach, sponsors, family), but it is important to inform the athlete that prehab does improve knee function. 

Research is finally coming out comparing the long term outcomes of patients with ACL injuries that did and didn’t have reconstructive surgery.  Ageberg et al (2008) found no difference in muscle strength, functional performance (hop tests) or limb symmetry at 2-5 year follow up.  Studies by Meuffels et al (2009) and Streich et al (2011) also showed no significant difference in functional outcomes or activities levels at 10 and 15 year follow ups respectively.  Another recent study from Lynch et al (2013) did show a significantly higher rate of return to level 1 sport in patients with reconstructed ACLs.  It is important to note that patients who had conservative rehab where advised not to return to level 1 sports. 

For years surgeons and physios have advised patients to have their ACL reconstructed to minimise the risk of osteoarthritis (OA) and further damage to the knee joint.  We now have some evidence (read above studies) to suggest this may not be true and the literature is unclear at this point in time whether ACL reconstruction does reduce OA and meniscus injury rates. 

So where does that leave us? Hopefully this flow chart will help you and your patient make an informed decision:

 

 

 

In my next post I’m going to discuss what should be included in prehab, rehab and when to return to sport.  Questions, comments most welcome on this topic!

LB

 

 

References:

1.  Meuffels, D.E., et al., Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes. British journal of sports medicine, 2009. 43(5): p. 347-351.

2. Eitzen, I., et al., A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury. journal of orthopaedic & sports physical therapy, 2010. 40(11): p. 705-721.

3.  Ageberg, E., et al., Muscle strength and functional performance in patients with anterior cruciate ligament injury treated with training and surgical reconstruction or training only: A two to five‐year followup. Arthritis Care & Research, 2008. 59(12): p. 1773-1779.

4. Orchard, J., et al., Intrinsic and extrinsic risk factors for anterior cruciate ligament injury in Australian footballers. The American journal of sports medicine, 2001. 29(2): p. 196-200.

5. Lynch, A.D., et al., Consensus criteria for defining ‘successful outcome’after ACL injury and reconstruction: a Delaware-Oslo ACL cohort investigation. British journal of sports medicine, 2013.

 

 

 

Scapula Dyskinesia

The shoulder blade or scapula (2 scapulae) is crucial to how the shoulder functions, but also plays a large role in our upper body posture and can contribute to neck pain.  Triangular in shape, the scapula lies against the back of the rib cage.  Anteriorly it is connected to the chest via the collar bone (clavicle). 

 Pictures from: http://en.wikipedia.org/wiki/Scapula  

 

The scapula can move in a number of planes allowing several different movements to occur:

·         Elevation and depression

·         Upward and downward rotation

·         Protraction and retraction

·         Anterior and posterior tilt

Picture from: http://www.xsens.com/images/stories/scapula_rotation.jpg  

 

Getting your head around these movements is important for assessing scapula posture at rest and under load.  Muscle balance around the shoulder blade, neck and thoracic spine effects the position of the scapula and thus the stability and mobility of the neck and shoulder.  17 different muscles attach to the scapula. 

1. Serratus Anterior
2. Supraspinatus
3. Subscapularis
4. Trapezius
5. Teres Major
6. Teres Minor
7. Triceps Brachii long head
8. Biceps Brachii
9. Rhomboid Major
10. Rhomboid Minor
11. Coracobrachialis
12. Omohyoid inferior belly
13. Lattisimus Dorsi
14. Deltoid
15. Levator Scapula
16. Infraspinatus
17. Pectoralis Minor

Having an appropriate group of muscles working around the scapula (force couple) enables the scapula to work effectively as a base for the shoulder to move from and limits excess strain on the neck.  An imbalance in these muscles often results in what is called scapula dyskinesis (a fancy name for a movement disorder of the shoulder blade).      

In the diagram below you can see the different pull of 3 muscles (lower traps, upper traps and serratus anterior) all attaching to the scapula.  This force couple is particularly important when the shoulder is moving and we see what is called scapulohumeral rhythm. 

Picture from: http://nateregensburg.blogspot.com.au/2010/12/increasing-upper-body-strength-by.html   

Today I particularly want to discuss the neutral position of the scapula when the arm is in neutral (by the side of the body).  You might ask why is that important when you don’t play sport with your arm held by your side?  We do, however, spend a lot of our day with arm/s close to our body – walking, working at a desk or computer, eating, sitting on the couch.  For athletes it’s important that they don’t have poor posture during the day, leading to muscle imbalance, before going to training or competition, as this can adversely affect their performance or cause injury     

The neutral position of the scapula is flat against the ribcage with no rotation, tilt or elevation present.   The medial border of the scapula should be vertical.    Landmarks commonly used to assess scapula position are the spine of the scapula at T3 and the inferior angle of the scapula level with T7.  This is not entirely accurate as the size of each scapula will vary depending on the size of the person. 

Modified picture from: http://en.wikipedia.org/wiki/File:Orientation.PNG

 

Commonly patients with neck and/or shoulder pain present to physiotherapy and winging scapula/e are noted on assessment.  Winging occurs when the medial (inside) border of the scapula lifts away from the ribcage.  We should consider 2 types and causes of winging:

1) Winging of the entire medial border – due to weakness in serratus anterior

2) Winging of the inferior angle of the scapula – due to weakness in lower trapezius

If you suspect weakness in serratus anterior it’s important to rule out a long thoracic nerve palsy.  This can occur from trauma or infection or be insidious.  It requires a longer period of rehab and referral for medical opinion. 

Both types of winging and other forms of scapula dyskinesia (e.g. downwardly rotated scapula at rest) require postural correction and exercise prescription. 

Far too often physios (and pilates instructors and other health professionals), cue people to pull their shoulder blades back and down to set a neutral scapula position.  The problem here is not all shoulder blades are sitting forward and up, so this cue to set the scapula is not going to correct all scapulae properly.  Having a generalised, non specific cue like “draw down and back” leads to problems. 

Remembering that the role of lower traps is to depress and upwardly rotate the scapula we need to have more specific cues for patients with scapula dyskinesia.

Highlighted below is the right levator scapulae muscle.  On the left, the overlying trapezius muscle is still present.  Levator scapulae elelvates the scapula, but also downwardly rotates the scapula (blue arrow) in combination with other muscles such as pec minor. This downward rotation is counterbalanced by the fibres of upper traps and lower traps (green arrow) with lower traps also balancing the elevation of the scapula.  The force couple between these muscles needs to work to enable a neutral scapula position.   

Modified picture from: http://en.wikipedia.org/wiki/Levator_scapulae_muscle

There’s no recipe I can give you for treating scapula dyskinesia and each patient will respond differently to different cues.  If you take the time to assess the scapula position properly and then base your postural cueing and exercise program on this I don’t think you can go wrong.  Tactile (palpation, sweep tapping, taping)  and visual (computer biofeedback) also help heaps!!

LB

 

Some other reading you might be interested in: Link here to a recent paper from scapula guru Ben Kibler and colleagues: Clinical implications of scapular dyskinesis in shoulder  injury: the 2013 consensus statement from the ‘scapular summit ’http://bjsm.bmj.com/content/47/14/877.full.pdf+html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

program on this I don’t think you