CHAPTER 117
Ligament Sprains
(Including Joint Capsule Injuries)
Presentation
Ligament strains occur when a joint is distorted beyond its normal anatomic 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 grade II or III sprains or a fracture). Alternatively, the patient may come to your office hours to days after the injury with a report of gradually increasing swelling resulting in pain and stiffness (suggestive of a grade I or II 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. Inability to fully extend an elbow is a strong indicator of significant injury. Use the uninjured limb as a control. Ligamentous injuries are classified as grade I sprains (minimal stretching causing pain without swelling or laxity); grade II sprains (a partial tear with pain, functional loss and bleeding with swelling and slight laxity), which can be managed conservatively; and grade III sprains (complete tear with significant pain, marked swelling, and gross instability), often requiring a rigid splint and possible surgical intervention. A tense joint effusion will limit the physical examination (and is one reason to require reevaluation 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, and release of any tense effusion.
Obtain radiographs (these can be deferred if findings are minimal with full range of motion without bony tenderness or if specific criteria are not met, as for ankle and knee sprains) (e.g., Ottawa Ankle and Knee Rules—see Chapters 97 and 115).
For first- and second-degree sprains, gently immobilize the joint using an elastic bandage alone or in combination with a cotton roll or plaster splint, as discomfort demands. Dynamic bracing (such as ankle stirrup splints and hinge knee braces) should be used with stable injuries when available. Most upper-extremity injuries can be immobilized by a sling alone or in combination with a soft or rigid splint.
Consider prescribing acetaminophen or 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 (third-degree sprain), the limb is usually best immobilized in a splint or cast—splint ankles at 90 degrees, wrists in extension, and fingers at slight flexion.
Provide narcotic analgesics when indicated.
Instruct the patient in rest, elevation above the level of the heart, and, when it provides comfort, application of ice 10 to 20 minutes each hour for the first few hours then three or four times a day for 3 days. Minor injuries may need only 1 day of treatment.
Explain to the patient that swelling in acute musculoskeletal injuries usually increases for the first 24 hours, and then decreases over the next 2 to 4 days (longer if the treatment above is not employed). Also inform the patient that some swelling and discomfort may persist for several weeks and at times for several months.
Advocate early mobilization and early return to normal functions for first- and second-degree sprains.
Explain the possibility of occult injuries, the necessity for follow-up, and the slow healing of injured ligaments (usually 6 months until full strength is regained).
What Not To Do:
Do not obtain radiographs 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 radiographs. They should be used as confirmatory evidence.
Do not obtain routine comparison views on pediatric patients. They usually do not improve diagnostic accuracy.
Discussion
A tense joint effusion will limit the physical examination (and is one reason to require reevaluation 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, and release of any tense effusion.
The benefit of cryotherapy for acute ligamentous injuries is controversial. For this reason, the use of ice should not be mandatory but should be used only when it is comforting to the patient.
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