This is a 12 year old male who presents to your clinic with a 1 day history of pain and tenderness over his right ankle. He states that he stepped on someone’s foot at basketball practice and "landed funny". It is painful to bear weight on his ankle, but he can do so if asked. He has been applying ice to the area since incurring the injury, with some relief of the pain.

Exam: VS are normal. His exam is unremarkable except for the right ankle, which is positive for moderate swelling and tenderness over the lateral malleolus. No ecchymosis or gross deformity is noted. Passive inversion and plantar flexion of the ankle produces pain. Anterior drawer test of the right anterior talofibular ligament is negative for gross laxity.

An X-ray of his ankle is obtained which does not reveal any fractures.

He is advised to rest the affected joint for today and is instructed to elevate his ankle and wear a compression bandage around the ankle. He is also instructed on performing pain-free range of motion exercises and light activity as tolerated.

The ankle is one of the most common sites for acute musculoskeletal injuries, and sprains account for 75 percent of ankle injuries (1). A sprain refers to stretching or tearing of a ligament. The most common mechanism of injury in ankle sprains is a combination of plantar flexion and inversion (1). The ankle joint is a hinge joint normally permitting movement in one plane (dorsiflexion and plantar flexion). In addition, up to 18% of axial rotation of the talus in the tibial mortise may occur (3). The lateral ligamentous complex consists of the three fibular collateral ligaments: the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and the posterior talofibular ligament. These ligaments stabilize the ankle laterally, and are commonly injured in ankle sprains (2). Most commonly attenuation, partial tear, or complete rupture of the ATFL results (4). Ankle sprains range in severity from grade I to grade III (1). Grade I refers to partial tearing of the ligaments. Grade II refers to partial to complete tear of the ATFL, and partial tear of the CFL. Grade III involves complete rupture of the ATFL and CFL (4).

History of the mechanism of injury allows the clinician to infer the pathologic status and structures involved (2). Patient will often report a twisting injury of the foot. The signs and symptoms of ankle sprains are varying degrees of pain, tenderness, and swelling over the lateral aspect of the ankle (4). Other signs are mild to moderate ecchymosis, loss of motion and function, and mechanical instability (1). Careful physical examination should include inspection, palpation, ability to bear weight on the affected ankle and special tests (1,3). Special tests include the anterior drawer test, which is used to assess the integrity of the ATFL. The inversion stress test is used to assess the integrity of the CFL (1). A positive "squeeze" test, which is occurrence of distal pain on compression of the fibula and tibia at the midcalf, may indicate the presence of a syndesmosis (the membranous ligamentous connections between the tibia and fibula) sprain (1). The positive findings of the affected ankle should be compared with the other, uninjured ankle (4). Traditionally, standard AP, lateral, and mortise views have been recommended in the evaluation of all cases of ankle injuries to rule out the possibility of occult fractures and osteochondral injuries and to assure articular congruity and alignment (2). The Ottawa Ankle Rules for obtaining radiographs of ankle injuries have modified this approach. These rules recommend radiographs if there is bony tenderness in the posterior half of the lower 6 cm of the fibula or tibia (i.e., lateral or medial malleolus tenderness), or inability to bear weight both immediately after the injury or during the medical examination (2).

The differential diagnosis of acute ankle sprains can include fibular fractures (lateral malleolus), tibial fractures, osteochondral fracture of the talar dome, peroneal tendon subluxation, congenital tarsal fusion, talar fractures, calcaneal fractures, and subtalar subluxation (4).

Early management of acute ankle sprains includes RICE (rest, ice, compression and elevation) (1). RICE and partial weight bearing are indicated as tolerated with optional crutches depending on the patient's ability to ambulate (4). Ibuprofen and/or acetaminophen may help with pain relief. Range of motion and gradual ambulation result in faster recovery compared to total rest (4). Surgery is indicated only in patients with recurring instability. Most patients have an excellent prognosis (4).

Nursemaid's elbow (also called subluxed radial head) is an injury which occurs when infants or children are lifted or pulled by the hand or arm. This pulling injury results in the radial head slipping through parts of the annular ligament resulting in the injury. Stubborn behavior (pulling away) may also cause this type of injury (4). This is one of the most common elbow injuries in young children between the ages of 1-5 years (4). The child may complain of pain in the elbow following a traction (pulling) injury. No significant swelling or angular deformity should be visible. They do not use their upper extremity and will hold their elbow at the side with their forearm on their lap (4). A classical physical exam finding of a nursemaid's elbow is refusal and pain with attempted forearm supination. Some parents may complain that the child has injured the wrist or shoulder, but in this age group, a pulling injury is most likely to affect the elbow. Physical examination of the infant may note point tenderness over the radial head, but this is not reliable (5).

The differential diagnosis of nursemaid's elbow includes buckle or greenstick fracture of the distal humerus, growth plate injury of the distal humerus or proximal radius. A history of a pulling injury makes a fracture unlikely. Radiographs may be necessary to rule out a fracture if the history is not consistent with a pulling injury or a fracture is suspected for other reasons. Treatment involves a reduction procedure. Various reduction procedures have been described. The most common procedure is the supination of the forearm (usually with the elbow in flexion, but it can also be done in other ways). Hyperpronation of the forearm with the upper extremity held up high has also been described. A click may be palpated at the level of the radial head suggesting successful reduction (5). The response to reduction of the displaced ligament is diagnostic. The child starts using the arm again, and there is usually no residual tenderness (4). The elbow may be immobilized in a sling for a day (usually not necessary), and if needed, acetaminophen can be given for pain (5). Parents are advised that this injury may recur up to age 5 or 6 years, but it does not signify any elbow problems in later life. It is prudent to minimize the risk of a pulling injury.

Knee problems are a common musculoskeletal presentation in primary care. The anatomy of the knee joint is very complex. Detailed description of all of its structures goes beyond the scope of this chapter. It is important to discuss some of the anatomical features of the knee that are more commonly injured. The tibiofemoral joint is a combination of a hinge, a sliding, and a gliding joint. There are several ligaments at this joint which are susceptible to injury. The medial collateral ligament (MCL) resists valgus angulation of the knee. The lateral collateral ligament (LCL) resists varus angulation. The anterior cruciate ligament (ACL) resists anterior displacement of the tibia on the femur. These ligaments are commonly injured. The menisci of the joint act to deepen the articular surfaces for load transmission, reduce stresses on joint surfaces, and act as a secondary stabilizer to enhance joint stability. These structures are also susceptible to injury. (8)

Patient history is a key element in evaluating the knee. Onset, type, quality, location, and duration of pain or other symptoms; (alleviating and aggravating factors), attempts to remedy the problem and any associated symptoms help to make the diagnosis (7). The mechanism of injury is a key factor in evaluating knee injury. Pivoting injury with a "pop" and swelling suggest an ACL injury. Twisting injury with a history of knee locking may indicate a meniscal tear. Varus or valgus forces point to the probability of LCL or MCL injury respectively. Physical examination of the knee includes observation, palpation of the soft tissues and bony anatomy, and range of motion of the affected knee in comparison to the unaffected knee. Specific testing of the knee for laxity of ligaments are helpful in making the diagnosis of knee injury. Some examples of these tests include the anterior drawer test to determine ACL laxity, and the valgus and varus stress tests to determine MCL and LCL laxity (8). McMurray's test and Apley's grind test are used to assess possible meniscal injury (4). It is important to remember that injury to one of the ligaments or menisci of the knee may be associated with other concomitant injuries to the knee. Therefore, it is important to examine the patient for those possibilities. Imaging procedures to evaluate knee injury include anteroposterior and lateral plain radiographs to rule out fractures. MRI may be appropriate to rule in possible ligamentous or meniscal injuries. Treatment depends on the type and severity of injury, which may include hinged bracing, analgesics for pain, surgical treatment and pursuant physical therapy. Most medial collateral ligament injuries may heal without surgery. Patient education on preventative measures such as proper conditioning prior to athletic activity is helpful (4).

Shoulder injuries in young athletes can be of various types. Acute dislocation and acute subluxation of the glenohumeral joint, chronic subluxation, impingement syndromes, rotator cuff injuries and acromioclavicular injuries are common injuries of the young athlete (6). Anterior dislocations comprise 85-95% of all shoulder dislocations and can occur in dominant and nondominant extremities (6). Patients often present holding the arm in slight abduction and internal rotation and report pain upon attempting to rotate the arm. A mass (the humeral head) may be palpable over the anterior shoulder (deltopectoral groove). The patient may also report "dead arm" syndrome; transient loss of sensation, numbness and tingling of the involved extremity. Axillary nerve injury may occur in this type of injury and presents by loss of sensation over the lateral deltoid as well as decreased strength of the deltoid.

A thorough history and physical examination are key to identification of shoulder instability. In patients with an acute injury, pertinent historical information include arm dominance, previous episodes of injury, and neurologic symptoms. Position of the extremity and direction of the force when the injury occurred are also important. Examination should include assessment of the neurovascular system, palpation of the musculature and the bony anatomy. Rotator cuff strength and range of motion, as well as documentation of external rotation are important findings that suggest acute dislocation. Standard radiologic studies of the shoulder include: anteroposterior views with shoulder in internal and external rotation, an axillary or modified axillary view and the Stryker notch view (6).

X-ray confirmation of a shoulder dislocation is preferable before a reduction procedure is attempted. It should be noted that fractures of the humerus are more common in children, while shoulder dislocations are more common in older teenagers. Acute dislocation requires prompt reduction. There are several common reduction methods. The Stimson technique utilizes a weight which is taped to the forearm. The patient lies prone with the weighted upper extremity hanging over the side of an elevated gurney. Reduction occurs gradually. The external rotation method is probably the easiest method, requiring the least assistance and equipment. With the patient lying supine or sitting upright, the procedure starts with the elbow flexed at 90 degrees with the forearm in a position of comfort and the humerus and elbow held adducted against the side of the chest. The humerus is slowly externally rotated using the forearm as a lever, keeping the elbow against the body. With gradual external rotation, reduction occurs spontaneously as the forearm begins to point away from the body in the coronal plane (i.e., extreme external rotation) (9). Following reduction, the arm should be immobilized for three weeks in a shoulder immobilizer (a sling with an additional strap to hold the forearm against the torso). In patients under age 25 years, many orthopedic surgeons believe surgical repair should be a consideration to prevent further episodes of anterior dislocation and arthritic changes. Rehabilitation of the injured shoulder involves exercises and close follow-up with a physical therapist or athletic trainer (6).

Questions

1. What is the usual mechanism of injury in an ankle sprain?

2. Which ankle ligament is most commonly injured?

3. Early management of acute ankle sprain employs RICE. What does this mnemonic stand for?

4. What is the mechanism of injury in nursemaid's elbow?

5. How do you reduce subluxation of the radial head (nursemaid's elbow)?

6. If you suspect an ACL knee injury in a patient, what specific test can you do to assess ACL laxity. Should you be worried about other injuries in this patient?

7. What nerve is commonly injured in an anterior dislocation of the shoulder. What are the typical neurologic deficits associated with this injury?

8. Describe two procedures to reduce an anterior shoulder dislocation.

Related x-rays

Ankle sprain: Inaba AS. Ankle Injuries: A Sprained Ankle ? In: Yamamoto LG, Inaba AS, DiMauro R. Radiology Cases In Pediatric Emergency Medicine, 1995, volume 3, case 3. Available online at: www.hawaii.edu/medicine/pediatrics/pemxray/v3c03.html

Series of ankle x-rays: Inaba AS, Yamamoto LG. Test Your Skill In Reading Pediatric Ankles. In: Yamamoto LG, Inaba AS, DiMauro R. Radiology Cases In Pediatric Emergency Medicine, 1995, volume 3, case 5. Available online at: www.hawaii.edu/medicine/pediatrics/pemxray/v3c05.html

Shoulder dislocation: Yamamoto LG. Closed Reduction of a Dislocated Shoulder. In: Yamamoto LG, Inaba AS, DiMauro R. Radiology Cases In Pediatric Emergency Medicine, 1996, volume 4, case 12. Available online at: www.hawaii.edu/medicine/pediatrics/pemxray/v4c12.html

References

1. Wolfe MW, Uhl TL, Mattacola CG, McCluskey LC. Management of Ankle Sprains. Am Fam Phys 2001;63(1):93-104.

2. Safran MR, Benedetti RS, Bartolozzi AR III, Mandelbaum BR. Lateral ankle sprains: a comprehensive review; Part 1: etiology, pathoanatomy, histopathogenesis, and diagnosis. Medicine and Science in Sports and Exercise 1999;31(7)Supp:S429-S437.

3. McRae R (ed). Clinical Orthopaedic Examination, 4th edition. 1997, New York: Churchill Livingstone.

4. Sponseller PD, Wenz JF, Frassica FJ (eds). The 5-Minute Orthopaedic Consult. 2000, Philadelphia: Lippincott Williams and Wilkins.

5. Hay WW Jr, Hayward AR, Levin MJ, Sondheimer JM (eds.). Current Pediatric Diagnosis and Treatment, 15th edition. 2001, New York: Lange.

6. Mahaffey BL, Smith PA. Shoulder instability in young athletes. Am Fam Phys 1999;59(10):2773-2782.

7. Crowther CL. Approach to knee problems in primary care. Lippincotts Prim Care Prac 1999;3(4):355-375.

8. Brinker, MR, Miller MD. Fundamentals of Orthopaedics. 1999, Philadelphia: W.B. Saunders.

9. Yamamoto LG. Closed Reduction of a Dislocated Shoulder. In: Radiology Cases In Pediatric Emergency Medicine. 1996, Volume 4, Case 12, or online at: www.hawaii.edu/medicine/pediatrics/pemxray/v4c12.html

Answers to questions

1. Combination of plantar flexion and inversion.

2. Anterior talofibular ligament.

3. Rest, Ice, Compression, Elevation.

4. Traction injury resulting from being lifted or pulled by the hand or arm.

5. Supination or hyperpronation of the forearm at the elbow.

6. Anterior drawer test assesses ACL laxity. Physician should assess for other structural abnormalities in the affected knee, as multiple ligaments and/or menisci may be injured.

7. Axillary nerve injury. Injury to the axillary nerve can result in transient loss of sensation, tingling and numbness to the lateral aspect of the deltoid.

8. Stimson technique or external rotation method. See text.