knee ANTERIOR CRUCIATE LIGAMENT INJURY
DEFINITION:
- The tearing of the anterior cruciate ligament (ACL), a primary stabilizer of the knee joint. (See illustration).
MECHANISM OF INJURY / HOW IT OCCURS:
- Results from a twisting (rotational) or hyperextension force to the knee joint.
- Often accompanied by damage to other structures of the knee, such as the meniscus.
SYMPTOMS:
- Individuals complain of sudden pain to the knee.
- Report feeling and sometimes hearing a “pop”.
- Swelling, giving way, and instability.
DIAGNOSIS:
- Physical examination will reveal swelling from bleeding into the joint (hemarthrosis).
- Generalized knee pain.
- Instability on ligament testing.
- Radiographs are of benefit to rule out fracture.
- Magnetic resonance imaging (MRI) can confirm the diagnosis and demonstrate other damaged structures that may coexist such as a meniscus tear.
TREATMENT/REHABILITATION:
- Initial treatment includes rest, ice, compression, and elevation. (R.I.C.E.).
- Occasionally aspiration (removing fluid from the joint) of the hemarthrosis may be performed especially if tense knee joint.
- Early range of motion exercises are emphasized.
- Bracing with an ACL functional brace.
- Rehabilitation concentrating on hamstring and quadriceps muscle strengthening. (See ACL injury exercises).
- ACL reconstruction in young and active individuals should be considered.