Ligament injuries

Injuries to the lateral knee ligaments, e.g. torn medial or lateral ligaments, are the most common sports injuries. Footballers and skiers in particular belong to the risk groups, as they often have to make rapid changes of direction and the lower legs are exposed to strong forces. In addition to knee pain, a lateral ligament rupture is characterized by restricted movement, bruising and swelling. Treatment depends on the severity of the tear, which is divided into three grades.

Inner ligament (MCL ligamentum collaterale mediale)

The most common knee injury often affects the inside of the knee joint. The medial collateral ligament (MCL) extends from the end of the thigh bone (femur) to the top of the shin bone (tibia) and is located on the inside of the knee joint. There are three main anatomical structures on the inner side of the knee, with the superficial medial collateral ligament being the largest and strongest. The other main structures are the posterior oblique and deep medial collateral ligaments. In the case of an inner ligament injury, the entire medial (inner) knee structures may be affected. A typical contact injury is the kick of the opponent on the outside with the development of valgus stress (x-leg position) in the knee and thus tearing of the medial collateral ligament complex.

External ligament (LCL-Ligamentum collaterale laterale)

The lateral collateral ligament (LCL), also called the fibular collateral ligament (FCL), is the main structure at the lateral or outer part of the knee joint. The term Fibular Collateral Ligament (FCL) is more anatomically correct, but this ligament is commonly referred to as the Lateral Collateral Ligament (LCL). The external ligament is a thin, round, thick ligament that runs from the femur to the lateral aspect of the fibular head. It serves to stabilize the knee joint against varus stress, and as part of the tension during extension, the ligament also prevents internal and external rotation, making them possible only in the flexed knee when the ligaments are loose. An external ligament injury can occur from a sudden stop and start, a blow to the inside of the knee, or an injury from contact or non-contact hyperextension. Sometimes the injury goes unnoticed or undiagnosed for several weeks before an athlete notices instability problems.

Typical symptoms of an inner ligament injury?

Pain directly over the ligament, swelling and inflammation over the inner (medial) part of the knee. In severe cases, patients feel the knee give way or even pop open. In order to evaluate the extent of the injury and diagnose additional injuries, we recommend performing a magnetic resonance imaging (MRI ) after clinical stability testing (valgus stress test with the knee extended and bent up to 30 °).

Severity of the inner ligament injury

The valgus stress test can also be used to classify the inner ligament tear into three different degrees of severity:

• Grade I: If the knee can be opened less than 5 millimeters, we speak of a first-degree injury. This is considered to indicate an inner ligament that is injured but still intact.
• Grade II: A second-degree injury is when the knee can be opened between 5 and 10 millimetres. The inner ligament is not (completely) torn (partial tear/tear of the inner ligament).
• Grade III: The highest degree of severity is considered to be the third-degree injury. In this case, the knee joint can be opened more than 10 millimeters. There is a complete tear of the medial collateral ligament.

Typical symptoms of an outer ligament injury?

Slight swelling and pain, difficulty stopping movements and changing direction. Instability of the knee shifting from side to side. Many athletes report unsteadiness and have a sensation that the knee is moving side to side. Unfortunately, Grade III lateral collateral ligament tears typically do not heal due to the unstable nature of the lateral knee compartment with two opposing convex surfaces and can lead to further instability. Diagnosis of an external ligament tear is made by a combination of physical examination (varus stress test) and radiographic techniques. Varus stress radiographs are very useful in determining the extent of lateral instability, especially in distinguishing a complete from a partial tear. Studies have shown that a distance greater than 2.7 millimeters from side to side is consistent with a complete tear of the lateral (fibular) collateral ligament and reconstruction should be considered.

More information will follow shortly.

More information will follow shortly.

Since, unlike the outer ligament tear, the inner ligament tear already heals well with conservative treatment, surgical interventions are rarely necessary for it. In general, most acute grade I and II injuries heal completely with a well-monitored rehabilitation program and sometimes temporary splinting (orthosis). Grade III must be considered in a more differentiated manner. In the case of a complete tear of the inner ligament, pronounced and chronic instability, surgical treatment with suture of the ligament or reconstructive surgery, e.g. with a tendon graft, is advisable. In the case of a combined injury of the inner ligament and the cruciate ligament, it is therefore important to check, for example, whether the inner ligament injury has healed completely before anterior cruciate ligament reconstruction or whether it should be repaired or reconstructed at the same time.

Important to know: chronic instabilities of the medial collateral ligament lead to failure of anterior cruciate ligament reconstruction in up to 20%.

The severity of the external ligament injury determines the treatment method. In less severe cases, immobilization (orthotic), ice, compression along with anti-inflammatory medications and pain medications can relieve discomfort and reduce swelling. An increase in strength and range of motion can be achieved through physical therapy to return the knee to a healthy functional state. For a complete tear, however, we usually recommend surgical treatment. This surgical procedure is typically performed as an open procedure in conjunction with arthroscopy. The torn collateral ligament is replaced with a tendon or tissue graft (posterolateral reconstruction using a modified Larson technique). We prefer this anatomical technique for surgical reconstruction, using an autograft (own semi- or gracilis tendon) or an allograft tendon. First, we ream a tunnel at the femoral attachment site slightly proximal and posterior to the lateral epicondyle. We then secure the graft at this site with a bio-interference screw in the prepared tunnel. The graft is then passed under the superficial layer of the iliotibial band and the lateral aponeurosis of the long head of the biceps femoris. Next, a tunnel is drilled through the head of the fibula (fibular head) beginning laterally at the exact attachment site of the external ligament to the fibular head and exiting on the medial aspect of the fibula just distal to the popliteofibular ligament. The graft is then passed through this and placed under tension in 20 degrees of flexion. A screw is then inserted to secure the graft in the fibular head. The operation is completed as soon as it is determined during the anesthetic examination that no more lateral unfolding is possible in the varus stress test.

Important to know: It is important to note that an MRI scan can be inaccurate - especially in chronic cases with tearing of the external ligament that has not healed completely.

More information will follow shortly.

Due to increasing sporting activity, the number of collateral ligament injuries in Germany is constantly rising. In our consultations, we find that many patients have similar questions. Therefore, we have compiled the most common points that come up during a detailed consultation for your information: