Joint laxity and ACL tears

This study indicates that athletes at risk of ACL injury should be assessed via a simple scoring system for increased joint laxity.

Training programmes should be specially focused on protecting such individuals from ACL injury.

Chronic anterior cruciate ligament (ACL) insufficiency can cause damage to the other structures of the knee like articular cartilage and thus early degenerative arthritis, meniscal tears, and stretching of secondary stabilisers such as collateral ligaments. Various risk factors for ACL tears have been known. These include excessive demands on unconditioned knees, knee flexion angle during landing, limb alignment, notch size, and hormonal fluctuations. Joint laxity is also considered a contributor. Its prevalence is higher in females and in Africans (than Caucasians) and decreases with age.

THE STUDY

In an Indian study, 135 men and 75 women who underwent ACL reconstructions between 2003 and 2010 were reviewed and compared with 55 male and 35 female controls (matched for age and gender) with no knee injury. Joint hypermobility was evaluated by 2 examiners using the Beighton score. The maximum score was 9, and a score of ≥4 was defined as hypermobility.

The majority (60.5%) of the patients with ACL injury and 23 (25.5%) of the controls had hypermobility. Among them, 58% and 24% were men and 65% and 29% were women, respectively. Thus, female gender was associated with more hypermobility. Patients with ACL injury were more likely to have joint hypermobility with an odds ratio of 4.46. In the current study, 26% of controls had hypermobility, which was similar to that for Iraqis and Chinese, but considerably higher than that for western populations. Asian Indians are significantly more mobile than English Caucasians.

Relevance of the study

Joint hypermobility may be acquired through repetitive training. Neuromuscular training is effective in increasing performance and preventing injuries in athletes. Strong muscles stabilize the knee joint. Training leads to superior muscle development and improved proprioception, which may reduce strain on ligaments surrounding the joint. Muscle training improves the stability of hypermobile joints and reduces the risk of ligament tears. Sportscoaches and health professionals should be trained to use the Beighton score to screen individuals with hypermobility and advise them prophylactic musculoskeletal rehabilitation.

Joint laxity & the Beighton Score

The Beighton Score is a simple 9-point scoring system for joint laxity that can easily be applied. Athletes scoring 4 or more out of nine can be considered as having an increased risk of ACL injury during sporting activities:

Add together:

• 1 point for each side if the thumb can touch the forearm when the wrist is flexed
• 1 point for each side if the little finder can be bent backwards to make an angle of 90 degrees or less in relation to the back of the hand
• 1 point for each knee if it can bend backwards when someone lifts up the heel from the bed when the person is lying on their back
• 1 point for each elbow that can bend backwards
• 1 point for being able to put the hands flat on the ground while standing bending forwards with the knees straight

The Score Result

If the score equals or is more than 4 out of 9 then athletes should undergo proper counselling to prevent these injuries and supportive orthotics, muscle and joint proprioceptive training to prevent ACL tears.

Reference:

Vaishya R, Hasija R. Joint hypermobility and anterior cruciate ligament injury. Journal of Orthopaedic Surgery. 21(2):182-4;2013.