Sprains: Ankle and Knee
Julie Adkins and Jill C. Cash
Definition
Sprains are ligament stretching or partial tearing from forceful stress on the joint. Sprains are categorized as follows:
A.Grade 1: Microscopic tears without ligament tearing or joint instability.
B.Grade 2: Partial tearing of involved ligaments and laxity of joint with moderate function loss.
C.Grade 3: Ligament tearing with severe function loss and joint instability.
Incidence
A.Ankle sprains are among the most common injuries seen in primary care.
B.Knee injuries are among the 10 most common causes of occupational injury and worker compensation claims.
Pathogenesis
A.Sudden stress to a supporting ligament causes ligament stretching or tearing. Sprains are usually the result of jumping, falling, or rotating a joint.
B.Ankle sprains are most often inversion sprains, with symptoms on the lateral side of the joint.
C.Eversion injuries affect the medial side.
D.Knee sprains most often involve the patellofemoral joint.
Predisposing Factors
A.Previous injury to ankle or knee.
B.Athletic activities.
C.Patellofemoral instability.
Common Complaints
A.I twisted my ankle or knee.
B.I stepped off of a step and came down on the side of my foot.
C.Swelling, pain, weakness of ankle or knee from a previous injury.
Other Signs and Symptoms
A.First degree: Minimal pain, mild to moderate pain with stress, little swelling, minimal tenderness with palpation, little functional loss, unimpaired weight bearing or walking, internal microdamage with full continuity.
B.Second degree: Moderate pain with range of motion (ROM), swelling, marked tenderness on palpation, moderate loss of function, difficulty with weight bearing or walking, mechanical dissociation with partial loss of continuity.
C.Third degree: Severe pain, especially with passive inversion, severe swelling, marked tenderness, marked decrease in ROM, intolerant of weight bearing or walking, joint instability, discoloration of skin, complete rupture of a ligament.
Subjective Data
A.Inquire about history of trauma.
B.Have the patient describe the injury: time, place, activity, predisposing factors, and time symptoms developed.
C.Determine if the symptoms are acute or chronic.
D.Inquire about the type and location of the pain.
E.Have the patient describe the pain and what conditions aggravate or relieve pain.
F.Ask if there are symptoms of popping, clicking, locking, recurrent swelling, or giving way of joint.
G.Ask if there is pain or other symptoms elsewhere, such as low back, hip, or leg.
H.Explore history of any previous ankle or knee injury.
I.Determine if the current injury was evaluated and treated previously.
J.Have the patient describe the ability to bear weight on the extremity and to tolerate ROM.
K.Review the patient’s medical history for arthritis, gout, cancer, autoimmune disorders, or metabolic disease.
Physical Examination
A.Check temperature, pulse, respirations, and blood pressure.
B.Inspect:
1.Observe ambulation. Note overall appearance and facial grimaces during exam.
2.Inspect injured area for swelling, discoloration, and deformity. Compare injured side to uninjured side.
C.Palpate:
1.Palpate the injured site for tenderness.
2.Palpate the joints above and below the injured site.
3.Perform ROM (active and passive), resisted ROM to evaluate strength.
4.Check for catching or locking of the knee on extension.
5.Assess the neurovascular status of the knee or ankle and distal extremity.
6.Ankle:
a.Palpate for tender sulcus in anterolateral aspect on inversion of the ankle.
b.Assess for pain with palpation over malleolar zone. Observe for bone pain with palpation over posterior edge or tip of lateral or medial malleolus.
c.Note if patient is able to bear weight on extremity.
d.Assess for pain aggravated by forced ankle inversion. Perform squeeze test and external rotation stress test to assess for syndesmosis.
e.Perform isometric test of plantar flexion and eversion,
d.Perform anterior drawer test, talar tilt test.
7.Knee: Palpate for tenderness on the medial and lateral joint line. Perform McMurray’s test to detect a torn meniscus (see Section II: Procedure for Evaluation of Sprains
). Symptoms of sprained knees:
a.Meniscus tear: Locking of knee with flexion and giving way of knee.
b.Collateral ligament tear or strain: Pain at lateral or medial sides.
c.Anterior cruciate tear: Popping sound at injury site and immediate swelling.
d.Posterior cruciate tear or strain: Pain in interior knee.
e.Patellofemoral syndrome: Popping or snapping, pain under patella with motion, and pain on stairs or hills.
f.Tendinitis: Pain over patellar tendon.
g.Prepatellar bursitis: Swelling over patella with inability to kneel due to swelling.
h.Nonspecific effusion: Effusion worse with exercise.
8.See Section II: Procedure for Evaluation of Sprains.
Diagnostic Tests
The Ottawa ankle rules can assist with clinical decision making if an x-ray is required for further assessment. These rules include ordering an x-ray series if the following exist (Stiell et al., 1994):
A.Pain in the malleolar zone and one of the following:
1.Bone tenderness at posterior edge or tip of lateral malleolus Or
2.Bone tenderness at posterior edge or tip of medial malleolus Or
3.Unable to bear weight immediately and in the emergency department for four steps.
A.Radiography of extremity, if fracture is suspected.
B.MRI, if mechanical symptoms and effusion persist.
C.Bone scans or MRI are usually reserved for those who have failed to respond after 6 to 12 weeks of therapy.
Differential Diagnoses
A.Ankle sprain:
1.Fracture.
2.Acute dislocation.
3.Infection.
4.Ligament strain.
5.Tendinitis or tenosynovitis.
6.Nonspecific foot or ankle pain.
B.Knee sprain:
1.Fracture.
2.Dislocation.
3.Septic arthritis.
4.Infected prepatellar bursitis.
5.Inflammation.
6.Tumor.
7.Meniscus tear.
8.Collateral ligament tear.
9.Anterior cruciate tear.
10.Posterior cruciate tear.
11.Collateral ligament strain.
12.Cruciate ligament strain.
13.Patellofemoral syndrome or chondromalacia.
14.Effusion, nonspecific.
15.Patellar tendinitis.
16.Prepatellar bursitis.
17.Nonspecific knee pain.
Plan
A.General interventions:
1.Reinforce the degree of injury and the need to take care of extremity to prevent further damage.
B. 
See Section III: Patient Teaching Guide RICE Therapy and Exercise Therapy.
Give the patient Section III: Patient Teaching Guide Ankle Exercises
or Knee Exercises.
1.Educate the patient regarding measures to improve healing. RICE: Rest, Ice, Compression, and Elevation therapy should be stressed.
2.Teach the patient techniques to protect the ankle and prevent future injuries. Techniques may include proper support (ankle brace) for the ankle when performing activities that will stress the joint (running, playing sports, etc.). Encourage the patient to perform daily exercises to strengthen the joint. Exercises of choice should be directed by physical therapy.
C.Pharmaceutical therapy:
1.Drug of choice:
a.Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation.
b.Consider one of the following: aspirin, ibuprofen, indomethacin, or piroxicam.
c.If there is increased risk for bleeding, acetaminophen with codeine may be used for pain.
2.Injectable medication:
a.Methylprednisolone acetate (Depo-Medrol) may be used if symptoms continue to be present 6 to 8 weeks after injury.
b.Repeat injection in 4 to 6 weeks if symptoms have not been reduced by 50%.
Follow-Up
A.Schedule initial follow-up in 2 weeks to evaluate current therapy or sooner if problems arise.
Consultation/Referral
A.Refer the patient to an orthopedic surgeon for the following: suspected fracture, positive squeeze test (syndesmosis injury), tendon rupture, dislocation, penetrating wound injury.
B.Refer the patient to an orthopedic surgeon if therapy is unproductive and symptoms have not begun to regress within 6 weeks.
C.Refer to physical therapy for evaluation and treatment to enhance healing of injury.
D.If no improvement with conservative treatment after 6 to 8 weeks, order an MRI to evaluate injury and refer to orthopedic surgeon.
Individual Considerations
A.Geriatrics:
1.Medication log of the geriatric patients should be available for interaction and consideration to this population for gastrointestinal, renal, cardiovascular, and endocrine disorders.
2.Research indicates that one in five minor injuries (such as sprains/strains) occur with adults ≥65 years old, and there is a higher acuity and longer length of stay with older adults than younger adults suffering from minor injuries.
3.Falls are the main cause of sprains/strains injuries for geriatrics. A thorough assessment of the home environment, activities of daily living (ADLs), traveling aspects, and areas the patients frequently visit is recommended to help prevent fall-related accidents and potential fractures.