Inability to fully straighten the knee

Introduction The inability to fully extend the knee joint is a clinical manifestation of knee collateral ligament injury. The joint capsule of the knee joint is weak, and the stability of the joint mainly depends on the ligament and muscle. The medial collateral ligament is the most important, followed by the lateral collateral ligament and the anterior and posterior cruciate ligaments. The knee is stretched straight, and the outside of the knee or leg is subjected to strong violence or heavy pressure, causing excessive knee abduction and partial or complete rupture of the medial collateral ligament. Conversely, the inside of the knee or leg is subjected to violent blows or heavy pressure, causing the knee to be excessively adducted, and the lateral collateral ligament may be partially or completely broken. In severe trauma, the collateral ligament, cruciate ligament and meniscus may be simultaneously damaged.

Cause

Medial collateral ligament injury: caused by valgus valgus.

Lateral collateral ligament injury: mainly caused by knee varus violence.

Anterior cruciate ligament injury: anterior cruciate ligament rupture can be caused by varus injury under knee extension and valgus injury under knee flexion.

Posterior cruciate ligament injury: Whether the knee is in a flexion or extension position, violence from the front that moves the upper end of the humerus can break the posterior cruciate ligament.

The knee is stretched straight, and the outside of the knee or leg is subjected to strong violence or heavy pressure, causing excessive knee abduction and partial or complete rupture of the medial collateral ligament. Conversely, the inside of the knee or leg is subjected to violent blows or heavy pressure, causing the knee to be excessively adducted, and the lateral collateral ligament may be partially or completely broken. In severe trauma, the collateral ligament, cruciate ligament and meniscus may be simultaneously damaged.

an examination

Related inspection

Knee joint separation test bone imaging grinding test blood routine Kellogg-Spid test

Clinical manifestations:

There is usually a history of obvious trauma. When you are injured, you can hear the sound of ligament rupture. Soon, you can't continue to exercise or work due to severe pain. There is local pain, swelling, and sometimes ecchymosis on the knee injury side. The knee joint cannot be fully extended. The tenderness of the ligament injury is obvious. When the medial collateral ligament is injured, the tender point is often at the lower edge of the femoral condyle or the medial condyle of the humerus; when the lateral ligament is damaged, the tender point is at the lateral femoral or humeral head.

an examination:

X-ray examination: Under local anesthesia, straighten the knee joint, according to the above inspection method, force the knee to receive or abduct, take a positive X-ray film, if the lateral collateral ligament is completely broken, the injured lateral joint gap is widened.

Magnetic resonance: The anterior and posterior cruciate ligaments can be clearly shown, and unexpected ligament structural damage and hidden fracture lines can be found.

Arthroscopy: It is important to diagnose cruciate ligament injury.

Lateral pressure test (separation test): The knee joint is straightened, the examiner holds the injured limb in one hand, and the large fish in the other palm rests on the inner side or the outer side of the lap, and strongly receives or abducts the calf, such as the medial side. The ligament is partially damaged, causing pain due to the ligament involved in the injury during abduction; if it is completely broken, there is abnormal abduction activity. Conversely, if the lateral collateral ligament is partially damaged, the ligament involved in the injury will cause pain during adduction; if it is completely broken, there will be abnormal adduction activity.

Drawer test: an increase in advancement indicates anterior cruciate ligament rupture, and an increase in posterior ligament rupture. It should be compared with the opposite side.

Axial shift test: A positive result indicates a rupture of the anterior cruciate ligament.

Differential diagnosis

The knee joint is weak and weak: some patients with strong anterior cruciate ligament have a tear in the knee joint. Some patients with strong trauma have a tear in the knee joint, then the knee joint is weak and weak, the joint pain is severe, and the swelling is rapid. There is blood in the joints, and there are subcutaneous ecchymoses around the joints, which often indicate that the joint capsule damages joint dysfunction.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.