The number of adolescents who participate in organized sports
has increased over the last few decades. In particular, the number of young
women participating in sports has grown very rapidly. With this increase has
come a corresponding increase in sports injuries. Forty percent of all pediatric
injuries are sports related. Estimates put this number at 4.4 million injuries
per year. Overall, male and female injury rates are becoming equal.
Injuries related to sports participation fall into two types of
trauma: micro (due to repetitive trauma) and macro (due to a single traumatic
event). Often these injuries are trivialized and the young athlete is asked or
encouraged to "toughen up and play through the pain." This approach is not in
the young athlete's best interest for the following reasons:
- It often leads to delayed healing and return to sports
- It can turn an easily treatable injury into one that becomes difficult
to treat, and
- In some cases, it can result in a prominent injury that precludes sports
participation
The adolescent is still growing. The growth plates (physis) are
cartilaginous (strong connective tissue) areas of the bones from which the bones
elongate or enlarge. Repetitive stress or sudden large forces can cause injury
to these areas. In the adolescent knee, such injuries include:
- Fracture—Breaking of the growth plates. A fracture through
the growth plate can be a very serious injury that can stop the bone from
growing properly. These fractures should be treated by an orthopedist, as
some will require surgery.
- Osgood-Schlatter's disease—Pain at the knob just below the knee
cap (tibia tubercle). Overuse injury may occur because of year-round
sports participation. This type of injury responds to rest and activity
modification. Adolescents will outgrow Osgood-Schlatter's.
- Sindig-Larsen-Johansson disease—Pain at the lower pole of the
knee cap (patella). Sindig-Larsen-Johansson disease is caused by overuse
and is treated with rest. Adolescents will outgrow it.
- Osteochondritis dissecans—Separation of a piece of bone from its
bed in the knee joint. This injury is usually due to one major macro
event, with repetitive macro trauma that prevents complete healing. This
injury is potentially very serious. Treatment varies from rest to surgery.
- Bipartite/multipartite patella—Results from failure of a bone
growth center to fuse normally. Rest is the first line of treatment, but
if pain persists, surgery may be required.
- Anterior knee pain—Anterior knee pain, or patella femoral
syndrome, is often passed off as growing pains. Causes of this pain
include overuse, muscle imbalance, poor flexibility, poor alignment, or,
more commonly, a combination of these. Anterior knee pain is one of the most
difficult adolescent knee injuries to sort out and treat. Accurate diagnosis
and treatment depends on finding a musculoskeletal specialist with a special
interest and expertise in this difficult area.
- Patellar instability—Patellar (kneecap) instability can range
from partial dislocation (subluxation) to dislocation with fracture.
Partial dislocation can often be treated conservatively. Dislocation with or
without fracture is a much more serious injury and usually will require surgery.
- Knee ligaments and the menisci (cartilage between the leg bones)
have greater blood supply and are more elastic in adolescents than in adults.
As adolescents near the end of bone growth, their injuries become more
adult-like and the adolescents become more susceptible to meniscal and
anterior cruciate ligament (ACL) injuries.
- Medial collateral ligament (MCL) injury—This injury results from
a lateral blow to the knee. Pain is felt on inner side (medially) of the
knee. MCL injuries respond well to protective bracing and conservative
treatment.
- Anterior cruciate ligament (ACL) injury—This injury is most
commonly caused by a non – contact twisting or deceleration mechanism which
results in excessive hyperextension or interval rotation forces on the
anterior cruciate ligament. Non-contact injuries of the ACL are becoming
more common than contact injuries. Adolescent females are at high risk.
Combination injuries with MCL or menisci are common. Surgical reconstruction
is needed if the adolescent wishes to continue participating in
"stop-and-start" sports.
- Meniscal injury—An injury to the meniscus, the crescent-shaped
cartilage between the thigh bone (femur) and lower leg bone (tibia).
These injuries usually result from twisting. Swelling, catching, and locking
of the knee are common. Nearly all of these types of injuries will require
arthroscopic surgery.