A Swollen Pediatric Joint

A 6 year old girl with a swollen right knee in the absence of trauma, fever, rash or lymphadenopathy. Symptoms are worse in the early morning, and improve throughout the day. She also complains of eye pain. What is the diagnosis?

Juvenile Idiopathic Arthritis (oligoarticular type)


Arthritis in children is not uncommon. When encountered by pediatricians, it is characterized into one of three subtypes: systemic, oligoarticular, and polyarticular.

• The oligoarticular type is the most common. Usually occuring around 5 years old, it is seen in the large joints (but not the hips) and is known for it's casual but unique association with uveitis (irritation of the eye) and a positive ANA (an antibody in the blood). If left untreated, this uveitis can lead to glaucoma when they are older.

• The polyarticular type is the second most common, and usually affects the large and small joints on both sides symmetrically. Older children with bloodwork that is rheumatoid factor positive are likely to progress to arthritis as adults.

• The systemic type is often easiest to recognize, as an adolescent will often present with fever, a salmon-colored rash, and lymphadenopathy. Many different joints can be affected, and treatment requires disease-modifying drugs (DMARDs). Untreated systemic JIA can progress to a dangerous condition known as macrophage activating syndrome. 

The disease is manageable when caught early, and is typically managed by a specialist known as a rheumatologist. An early step is be sure the swelling isn't the result of an athletic injury or fall. The pediatrician will be sure to rule out more serious causes such as a septic (infected) joint.

Your child's sports injury: the foot

Ankle injuries are considered the most common type of athletic injuries. If your adolescent or teen has suffered an injury, the most likely cause is a sprain. The treatment for a sprain is RICE (rest, ice, compression and elevation) for the first 48 hours, followed by rehabilitation. However, here are a few lesser known injuries that may be to blame:



Stress Fractures
Metatarsal Stress Fracture
This is a small crack in one of the metatarsal (toe) bones, usually the 2nd or 3rd toe, and typically occurs in runners. There will be point tenderness over the area on examination. Treatment is rest for 6 weeks and using shoes with good arch support.

Navicular Stress Fracture
This is a tricky fracture of the upper bone in the foot called the navicular bone that occurs in athletes in running sports. They complain of vague, non-localizing pain at the dorsum (top) of the foot. These do not show up on imaging right away, so after a few weeks an MRI may be needed to make the daignosis. Treatment is casting and immobilization for 8 weeks

Calcaneal Stress Fracture
Fracture of the heel bone. Occurs in athletes engaging in running sports, and is characterized by pain in the heel with walking or running. Pain can be elicited on exam by squeezing the heel bone. Imaging may be needed to make the diagnosis, and treatment is 8 weeks of immobilization.



Sever Disease
Inflammation of the bottom of the Achilles tendon where it attaches to the heel bone (calcaneus). It occurs in prepubescent boys, during exercise, in both lower legs. The treatment is RICE and shoes with good arch support, and will heal in about 2 months.



Plantar Fasciitis
Athletes will report morning heel pain after several hours of rest or during the first few steps of the day. The treatment is rest, and pain is gone after about 6 months.

The Newborn Foot Examination

One of the most common questions asked by new parents concerns their newborn's feet. "Is this normal?" is an appropriate question to ask when a body part on your child doesn't quite look right. 

Though changes in the angles of the feet are typically normal, it is imperative that the pediatrician rules out conditions that require closer observation and management. Here is the "differential diagnosis" for oddly shaped baby feet:

Metatarsus Adductus

The "forefoot" or front part of the foot is turned in (adducted) toward the center, while the middle and hint foot portions are normal. Typically caused by "intrauterine molding", or the way the baby was positioned in the womb. The physician will perform a quick test to be sure the forefoot can be moved to midline without resistance. If the feet are too rigid, a referral to a pediatric orthopedist is warranted. There, the feet may be placed in special "reverselast" shoes and reevaluated in 6 weeks. If this does not fix the problem, serial lower leg casting may be required. The last step would be surgery, which isn't done until 4 years of age. 

Talipes Equinovarus (clubfoot)

The whole foot is adducted. As with above, a quick test for rigidity is performed. If correctable, it is referred to as "positional clubfoot" and is simply observed over time. The more serious diagnosis is congenital clubfoot, which occurs in 1 out of every 1,000 births. Congenital clubfoot requires x-ray imaging, referral to pediatric orthopedics and treatment with special casting referred to as the "Ponseti method". Surgery may be required between ages 3-12 months. 

 

Pes Planus (flat foot)

The lack of an identifiable arch in the foot. This is quite common, seen in approximately 1 in every 4 children. This condition is simply observed over time, since arches typically develop by age 10. If the child complains of pain in the feet as they get older, they may require stretching exercises or special shoes. 

Congenital Vertical Talus (rocker bottom foot)

Rocker bottom feet are characterized by elevated, dislocated, midfeet. The condition is typically associated with genetic syndromes or single gene deletions. Referral is made to pediatric orthopedics.