Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Ligament injuries

Ligament injuries in athletes are common, particularly around the knee and the ankle. They also occur in the shoulder, elbow, and thumb

Functional anatomy

Ligaments are attached to the two bones that compose the joint . Ligaments provide stability to the joint, while still allowing motion. They cannot actively resist motion, but provide a ‘check rein’ against instability at the extreme range of motion of the joints. Because of their microstructure ligaments resist tensile forces (pulling apart) well, but are of little value for compressive forces. Ligaments are injured when forces exceed the ligament’s ability to resist a load, which may depend on the rate of injury. Ligaments provide more strength when a load is applied slowly: this is why relatively
slow injuries may cause an avulsion fracture (where a small piece of bone breaks off at the ligament attachment) rather than tearing the ligament itself. Fast injuries will cause the ligament to fail before the bone, and resulting in a tear in the midsubstance of the ligament. When the athlete sprains an ankle the two bones of the ankle joint, the tibia and talus, are rapidly forced apart, causing rupture of the ligaments holding the tibia and talus together.

Types of ligament injury

ligament tear may affect only a few fibers or the entire ligament. In clinical practice it is practical to distinguish between partial and complete tears because the treatment and prognosis are different. A partial tear may be classified as a grade I tear (disruption of a few fibers) or a minor grade II tear (disruption of less than half the fibers); in both cases the joint is stable. A major grade II tear corresponds to disruption of more than 50% of the fibers; a grade III tear corresponds to disruption of all the fibers as a complete tear; in both cases the joint is unstable to a varying degree. A disruption of the fibers of the ligament is often accompanied by bleeding which spreads into surrounding tissue and is frequently seen as bruising. An injury to a ligament within the joint or to the joint capsule may cause hemorrhage into the joint space. Injuries to ligaments can also be accompanied by damage to the articular cartilage surface.

Symptoms and diagnosis

The following symptoms suggest that a ligament injury has occurred:
– bruising, swelling and tenderness around the affected joint caused by bleeding;
– pain when the limb is moved or loaded; there can also be pain on palpation;
– instability of the joint depending on the type of joint and the extent of the injury.
An MRI scan can often show the extent of the ligament injury if the diagnosis is unclear. In all cases of suspected ligament injuries the joint should be tested for stability.

Treatment

In cases of suspected acute ligament injury the athlete or trainer should:
– support the joint by elastic bandage or a brace;
– apply compression if there is bleeding;
– cool the joint;
– rest and avoid loading of the area (the use of crutches is often valuable);
– elevate the limb.
The doctor’s function is:
– to determine the stability of the joint (sometimes it is necessary to perform a stability test under anesthesia if the pain is severe);
– to exclude the possibility of a fracture by taking X-rays;
– if the joint is stable, to prescribe early mobilization exercises. A supportive adhesive tape or an orthosis
may be valuable depending on the nature and location of the injury. Early motion is important;
– if the joint is unstable, to decide whether the treatment should be nonoperative with early protective motion exercises or application of a supportive adhesive strapping, tape, brace, or cast, or whether surgical treatment is required.

Rehabilitation
Active muscular exercise and mobility training is of the greatest importance during the rehabilitation phase and should be carried out with cooperation between the athlete, coach, doctor, athletic trainer and physical therapist.
The healing of a ligament after an injury can take a long time, usually more than 6 weeks. If the ligament is part of a capsule, like the medial collateral ligament of the knee, early motion is usually allowed in combination with orthotic support. If the ligament is intra-articular, like the anterior cruciate ligament of the knee, the joint is subjected to early motion and/or to later surgery. Early motion exercises for the joint as a whole are usually desirable but should not create a dilemma for the doctor applying treatment. The
exercises must not affect the healing of the injured ligament. In the absence of a fracture or dislocation, all injuries that cause swelling in or around joints and all sprains causing bleeding, swelling, and tenderness should be treated as ligament injuries.

Healing and repair

Ligaments heal by the same response as other tissues. Initially, an influx of inflammatory cells brings repair cells to the region; the cells clean up dead tissue and prepare the region for new tissue. Following this, new blood vessels develop in the area, eventually leading to new cell formation and finally production of new structural tissue between the living cells. The initial tissue is immature, so a period of maturation must take place before healing is complete. This entire process takes many months. However, for most ligament injuries sufficient strength is achieved by about 6–12 weeks to begin strengthening exercises around the joint. This process can begin much earlier for cases of partial tears.

Dislocations
All joints are surrounded by a joint capsule and ligaments. For a dislocation to occur, at least part of the capsule and its ligaments must be torn; therefore any dislocation involves injuries to these structures and sometimes to the articular cartilage. Rehabilitation will depend upon how quickly these damaged tissues heal. Complete dislocation (luxation) of a joint indicates that the opposing articular surfaces have become separated and are no longer in contact with each other. Partial dislocation (subluxation) of a joint indicates
that the articular surfaces remain in partial contact with each other but are no longer correctly aligned. Again, there may be capsule, ligament, and cartilage injuries.

Location
Complete dislocations most frequently affect the shoulder, elbow, finger joints, and patella, while partial dislocations usually affect the knee and ankle joints. The acromioclavicular joint can be subject to a complete or a partial separation (see below).

Symptoms and diagnosis
The following symptoms suggest a dislocation:

– pain on movement;

-abnormal contour of the joint;
– swelling and tenderness;
– instability of the joint of varying degree;
– An X-ray will determine whether a fracture has occurred and may also determine the degree of dislocation, whether it is partial or complete.
Treatment
The doctor’s function is to reduce the joint, i.e. to manipulate the articular surfaces of the bones back to their normal positions, with the help of local or sometimes general anesthesia. Further treatment is aimed at restoring the stability and function of the joint. Depending upon the degree of instability present, the doctor will suggest the most suitable treatment for the joint involved. This can include early mobilization with strength training or immobilization for a varying period (1–6 weeks) followed by exercises or surgical treatment. Injuries may recur in the shoulder joint and the patella; young athletes are particularly susceptible, especially after inadequate treatment or rehabilitation. Dislocations may be complicated by damage to nerves and blood vessels.

Separations
The term ‘separation’ is most commonly applied to injuries of the acromioclavicular joint—the joint on top of the shoulder between the clavicle (collar bone) and acromion (the extension of the shoulder blade). Injury
to the ligaments holding the clavicle in position allows upward displacement of the clavicle.
Meniscus and disk injuries
Meniscus injuries of the knee are described on. A small meniscus-like structure is sometimes present in the acromioclavicular and sternoclavicular joints on the shoulder. A small disk is present in the radioulnar joint of the wrist.


Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>