9.12 Ligament Sprains (Including Joint Capsule Injuries)

agk’s Library of Common Simple Emergencies

Presentation

A joint is distorted beyond its normal anatomical limits (as when an ankle is inverted or a shoulder is dislocated and reduced) The patient may complain of a snapping or popping noise at the time of injury, immediate swelling, and loss of function (suggestive of second- or third-degree sprain or a fracture); or he may corne in hours to days following the injury, complaining of gradually increasing swelling and resulting pain and stiffness (suggestive of a first- or second-degree sprain and development of a traumatic effusion).

What to do:

• Obtain a detailed history of the mechanism of injury, and examine the joint for structural integrity, function, and point tenderness. Use the uninjured limb as a control.
• Obtain x rays (these can be deferred if necessary).
• With first-degree and second-degree sprains, gently immobilize the joint using an elastic bandage alone, or in combination with a cotton roll and/or plaster splint, as discomfort demands.
• Consider prescribing anti-inflammatory pain medication when the patient complains of pain at rest and provide crutches when discomfort will not allow weight bearing.
• If there is a fracture or ligament tear with instability, the limb is usually best immobilized in a splint or cast. Splint ankles at 90 degrees, wrists in extension, fingers at slight flexion.
• Instrurt the patient in rest, elevation, and application of ice (10-20 minutes each hour) for the first 24 hours.
• Explain to the patient that swelling in acute musculoskeletal injuries usually increases for the first 24 hours, and then decreases over the next 2-4 days (longer if the treatment above is not employed) and that some swelling and discomfort may persist for several weeks and at times for several months
• Explain the possibility of occult injuries, the necessity for followups, and the slow healing of injured ligaments (usually 6 months until full strength is regained).

What not to do:

• Do not obtain x rays before the history or physical examination. Films of the wrong spot can be very misleading. For example, physicians have been steered away from the diagnosis of an avulsion fracture of the base of the fifth metatarsal by the presence of normal ankle films.
• Do not base the diagnosis on x rays. They should be used as confirmatory evidence.

Discussion

Ligamentous injuries are classified as first-degree, (minimal stretching); second-degree (a partial tear with functional loss and bleeding but still holding); and third-degree (complete tear with ligamentous instability, often requiring a cast). A tense joint effusion will limit the physical examination (and is one reason to require re-evaluation after the swelling has decreased) but also suggests less than a third degree ligamentous injury, which is normally accompanied by a tear of the joint capsule.

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