Musculoskeletal Conditions

Children with extremity or joint pain often have a history of a fall or sports injury. However, evaluation can be challenging in younger children and in those with an unwitnessed injury. Identifying emergent conditions, including nonaccidental trauma and those requiring hospitalization or prompt specialist referral, is critical in the urgent care setting.

In this section, we review important causes of noninfectious limp, extremity pain, and joint pain in children and provide an overview of splinting techniques:

• Limp:

  • Toxic Synovitis

  • Sprains, Strains, and Fractures

  • Overuse Injury

    • Osgood-Schlatter Disease

    • Sever Disease (Calcaneal Apophysitis)

• Nursemaids Elbow (including reduction technique)

• Splints

Limp

A thorough history and physical examination is important to narrow the wide differential diagnosis of limp and obtain the most appropriate diagnostic tests.

• Infectious causes of limp (e.g., septic arthritis and osteomyelitis) are covered in the Pediatric Infectious Diseases rotation guide. There you will find information on diagnostic workup, including laboratory and imaging tests, as well as management. Refusal to bear weight, limited range of motion, joint or extremity swelling, or joint or bone pain accompanied by fever should raise suspicion for an infectious cause of limp. The differential includes cellulitis, myositis, septic arthritis, and osteomyelitis.

• Two causes of noninfectious nontraumatic limp, Legg-Calvé-Perthes (LCP) disease and slipped capital femoral epiphysis (SCFE), are covered in the Pediatric Rheumatology rotation guide.

Toxic Synovitis

Toxic (transient) synovitis is inflammation of the synovium, most often at the hip. It is the most common cause of hip pain in pediatric patients and most often affects children ages 4-8 years. Toxic synovitis is frequently seen after an upper respiratory viral infection. Patients may have fever and limp or refuse to walk. On examination, patients will typically present with the hip in flexion, abduction, and external rotation and will resist internal rotation. Limping will generally improve in 24−48 hours with supportive management.

Evaluation:

• Imaging with anteroposterior and lateral or frog-leg hip radiographs may be obtained but is usually normal in toxic synovitis, although it can help in identifying other, less common conditions. Ultrasound is not diagnostic but may be helpful if there is suspicion for septic arthritis, because it can help differentiate between the presence of intracapsular fluid in septic arthritis and findings of isolated synovial membrane inflammation in toxic synovitis.

• Laboratory testing is indicated if the patient has fever or there is concern for septic arthritis. If concern for septic arthritis persists after lab and ultrasound evaluation, synovial fluid aspirate should be obtained.

Differential diagnosis: Toxic synovitis is a diagnosis of exclusion; it is important to exclude emergent conditions, especially septic arthritis and osteomyelitis, when evaluating patients.

The Kocher criteria are helpful in differentiating between septic arthritis and toxic synovitis. The more positive findings a patient has on the Kocher criteria, the more likely the patient is to have septic arthritis rather than toxic synovitis.

Sprains, Strains, and Fractures

Sprains, strains, and contusions: Extremity pain may be due to soft-tissue injury, such as contusion, ligament sprain, or muscle or tendon strain. Radiographs generally will be normal in such patients and often can be avoided based on history and physical examination. If a fracture is not suspected, conservative treatment with rest, elevation, ice, and nonsteroidal anti-inflammatory drugs (NSAIDs) is recommended. A splint or sling is sometimes appropriate for comfort or support. Patients with persistent pain despite conservative measures should be reevaluated or referred to orthopedic surgery.

The following two clinical decision tools can be helpful to identify patients who may benefit from imaging after ankle injury:

• The Ottawa ankle rule was initially validated in adults to determine when radiographs of ankle and foot are indicated. Additional research supports its utility in children older than 5 years.

  • Ankle radiographs are indicated if the patient has malleolar pain and either tenderness along the distal 6 cm of the posterior malleolus or inability to bear weight for four steps after injury and in emergency department (ED).

  • Foot radiographs are indicated if the patient has midfoot pain and tenderness to the navicular bone or base of the fifth metatarsal or is unable to bear weight for four steps after injury and in ED.

• The low-risk ankle rule can be used in patients aged 3−16 years to determine if radiographs are not indicated clinically. However, this examination does not “rule out” fracture.

  • Radiograph is not necessary if the patient has a low-risk examination, defined as pain and/or tenderness of the distal fibula, below the level of the joint line of the ankle and/or over the adjacent lateral ligaments.

  • These exam findings are more consistent with a low-risk injury (e.g., sprains, contusions, and distal fibular fracture, including avulsion fractures, metaphyseal buckle fractures, and nondisplaced Salter-Harris types I and II fractures).

Fractures: Children’s ligaments are stronger than their growth plates, making children generally more likely than adults to sustain a fracture instead of a sprain. A high index of suspicion is required for fractures through the growth plate (Salter-Harris type I). These fractures may not be visible on initial radiographs. Patients with swelling or point tenderness near a growth plate should be treated conservatively for occult fracture and instructed to follow up with orthopedics.

(Reprinted by permission from Springer Nature: Classifications in Brief: Salter-Harris Classification of Pediatric Physeal Fractures. Clin Orthop Relat Res 2016.)

• type I fracture: separation through the physis

• type II fracture: enters in the plane of the physis and exits through the metaphysis

• type III fracture: enters in the plane of the physis and exits through the epiphysis

• type IV fracture: crosses the physis, extending from the metaphysis to the epiphysis

• type V fracture: crush injury resulting in injury to the physis

When managing fractures, it is important to determine those that should be evaluated by orthopedic surgery immediately. Indications for urgent or emergent orthopedic evaluation include:

• open fracture

• displaced fracture

• dislocated fracture

• complete fracture

• fracture in children with underlying bone disease

• concern for neurovascular compromise or compartment syndrome

• Salter-Harris fractures types III, IV, and V

See Trauma in the Pediatric Emergency Medicine rotation guide for an overview of pediatric extremity fracture patterns, including fractures in toddlers.

Overuse Injury

Osgood-Schlatter disease (apophysitis of the tibial tubercle): Osgood-Schlatter disease occurs at the proximal tibia due to traction of the quadriceps muscle through the patellar tendon. Osgood-Schlatter disease typically occurs during the early adolescent growth spurt between ages 10 and 15 years, particularly in children who participate in sports that involve running and jumping (e.g., basketball). Patients report knee pain, often bilateral, that is worse with activity. On exam, tenderness can be elicited at the tibial tubercle, with some soft-tissue swelling. However, strength and knee range of motion is normal. Osgood-Schlatter can be diagnosed clinically, but radiographs can support the diagnosis and may help exclude a fracture in situations where there was a recent traumatic injury.

Treatment consists of rest, NSAIDs for pain, and ice to the area. Physical therapy may be indicated for athletes. Pain generally resolves as the tibial tubercle closes, which is generally at age 14-15 years.

(Source: Osgood-Schlatter Disease. N Engl J Med 2018.)

Sever disease (calcaneal apophysitis): Sever disease affects the calcaneal apophysis. This generally presents in children who are active in sports that require significant heel involvement, such as running.

On examination, patients have tenderness of the posterior or plantar surface of the heel and pain when the sides of the heel are squeezed. Radiographs may show fragmentation of the calcaneal apophysis. Treatment requires rest, stretching of the Achilles tendon, ice, and NSAIDs for pain relief. Orthotics can be helpful. Referral to orthopedic surgery is recommended for patients who do not have a response to conservative management.

(Source: Sclerosis and Fragmentation of the Calcaneal Apophysis. WikipediaCommons. Accessed October 2020.)

Nursemaids Elbow

Subluxation of the radial head, or displacement of the annular ligament, is commonly known as nursemaids elbow. It is a common childhood injury, especially in toddlers, and is rare in children older than 5 years due to thickening and strengthening of the annular ligament.

(Source: Reduction of Pulled Elbow. N Engl J Med 2014.)

(Source: Reduction of Pulled Elbow. N Engl J Med 2014.)

Presentation: The history often suggests a sudden, longitudinal traction force that was applied to the hand with the elbow extended, followed by immediate refusal to use the arm. This may be due to a caregiver attempting to catch a child who is falling. Caregivers may report hearing a click with arm pulling.

The patient typically holds the elbow in flexion with the forearm pronated. Elbow tenderness may be present. While patients should be able to flex and extend at the elbow, they typically refuse to supinate the elbow due to pain. Swelling of the elbow suggests a potential fracture and should be imaged.

Reduction techniques: Radiographs are not indicated if there is a history suggesting a traction injury in toddlers who hold their arm in flexion and pronation without swelling on examination. In these situations, the elbow can be reduced either utilizing the supination technique or hyperpronation technique (see a video of the reduction technique). Within several minutes of reduction, the child should be able to use the arm. If they do not, alternate diagnoses should be considered. Parents should be informed that nursemaids elbow may recur and advised to be careful when lifting their child.

Splints

Splints are used for temporary immobilization of confirmed and suspected fractures and soft-tissue injuries. A variety of materials are used for splinting, including prefabricated splints (e.g., ankle air splints or wrist splints), fiberglass products that can be cut to size, and plaster. Unless a prefabricated splint is being used, the following layers are usually recommended:

• stockinette to protect the skin

• Webril to protect skin and pressure points

• splinting material (e.g., fiberglass or plaster)

• compression wrap (Ace bandage)

Generally, splints for fractures in the bone shaft should immobilize the joint above and below the injury. Fractures near a joint should stabilize the bones on either side. Potential contraindications for splints include open fractures, concern for compartment syndrome, infected wounds, and high risk for skin infection. Neurovascular status before and after splint application should be evaluated. Families should be instructed not to remove the splint, and to keep it dry. Patients should not bear weight on a splint. See a video and helpful reference guide on splinting techniques.