ACLdeficient

ACLdeficient refers to a knee in which the anterior cruciate ligament (ACL) is torn or otherwise unable to function, resulting in compromised stability. It most commonly arises from acute sports injuries involving sudden deceleration, pivoting, or hyperflexion, but can also be the result of chronic degeneration. The condition may occur in isolation or with injuries to other knee structures, such as the menisci or collateral ligaments.

Pathophysiology manifests as increased anterior translation of the tibia relative to the femur and greater rotational laxity. Patients frequently report a sense of instability or “giving way,” especially during cutting or jumping activities, and may experience swelling from hemarthrosis. Physical examination often reveals a positive Lachman or anterior drawer test and a pivot-shift maneuver indicating instability.

Diagnosis relies on history and examination, supported by imaging. Magnetic resonance imaging (MRI) confirms ACL disruption and assesses associated injuries to menisci, cartilage, and other ligaments. Plain radiographs help identify bone bruises, avulsions, or other osseous injuries.

Management options depend on activity level, instability severity, and patient goals. Nonoperative treatment with structured rehabilitation may be appropriate for low-demand individuals, focusing on range of motion, strength, and neuromuscular control. Active or competitive individuals, or those with persistent instability, commonly undergo ACL reconstruction using autograft or allograft tissue, followed by a staged rehabilitation program. Prognosis varies with treatment choice and adherence; untreated ACLdeficiency carries a higher risk of meniscal injury and early degenerative changes, while proper repair and rehabilitation can restore function in many patients.