Knee Injuries in Adolescence

Incident, Prevalence and Mobility

Why Adolescents are Prone to Knee Injuries

Adolescence is a specific and unique development phase defined by growth and development. Biologically, physically, cognitively, psychologically and socially, growth is more rapid during this stage than any other growth period, excluding infancy. A large number of sporting injuries occur in adolescents, with sport and physical activity being the leasing cause of injury related visits to pediatric emergency departments in the United States. Both the incidence and severity of sports related injuries increase during the period of adolescence comparative to that of childhood. A recent one-year prospective study found that, at baseline, as many as 53% of pre-teens and early adolescents have experienced muscular skeletal pain at some point during their lives, with 21% of those who were pain free at baseline. There is a high risk of sporting injury and muscular skeletal pain in the adolescent population with the knee appearing to be particularly susceptible to injury. 

Gender Differences in Knee Injuries

It is during adolescence that gender differences begin to emerge in injury profiles related to sport and physical activity. As age increases, there appears to be a greater difference in injury rate and profile between genders. The gender bias in injuries is frequently described at the knee. While males have a higher overall rate of knee injury females have a higher rate of major knee injury and are twice as likely to sustain a major non-contact knee injury. It has been reported that female adolescents have a four to six times higher rate of non-contact ACL injury compared to male adolescents. Literature regarding PFPS in the knee recorded that adolescent females are at double the risk of adolescent males with an overall rate of 21-45%. 

Long-Term Implications of Knee Injuries

Knee injuries sustained during adolescence may have long-term implications. There is evidence that suggests patellofemoral pain syndrome (PFPS) may become chronic, with one in four adolescent females who still had pain at 4 years continuing up to 20 years after their initial presentation. An additional long term impact of knee injury is the potential impact on physical activity. During adolescence females statistically many females become less active, pain and injury are among a number of factors that may contribute to the decline in participation in physical activity and exercise. The government recommends 60 minutes of moderate exercise per day, including at least 20 minuets of vigorous activity 4 times per week. It is extremely important for adolescent females to participate in vigorous activity as higher intensity weight bearing exercise appears to be most beneficial for promoting bone mass and prevention of osteoporosis later in life. Adolescence appears to be the critical time to maximise bone mass in females. Inability to meet the government guidelines for physical activity may have long-term implications for the health of female adolescents and the wider community. It is essential to understand the why female adolescence are at a greater risk , in order to develop and implement correct prevention and management strategies.