Apophysitis (Traction Apophysitis)

What apophysitis is

Children's bones grow from cartilage growth plates. Most are near the ends of long bones. An apophysis is a secondary growth center at the site where a large tendon attaches. Until it fuses with the main bone in the mid to late teens, it is weaker than the tendon pulling on it.

During a growth spurt, bones lengthen faster than muscles and tendons, so tendons become relatively tight. Repeated running, jumping, kicking or throwing then pulls hard on the apophysis many times a day. Tiny injuries and inflammation develop at the cartilage, causing pain. This is called traction apophysitis.

Types of apophysitis

Symptoms

• pain over a specific bony point that worsens during and after sport
• tenderness when the spot is pressed
• swelling, and sometimes a growing bony bump (especially below the knee in Osgood-Schlatter)
• knee pain with kneeling (knee forms), or heel pain when walking barefoot or on tiptoe (Sever)
• limping after activity, or walking on toes to avoid heel pressure
• tight calves, hamstrings or thigh muscles

Pain is usually better after rest and worse at the start of a new season or after a big increase in training. One or both sides can be affected.

Causes and risk factors

• a recent growth spurt
• repetitive running, jumping or throwing, especially on hard surfaces
• playing one sport all year, or several teams at once
• sudden increases in training load
• tight muscles and poor flexibility
• flat feet or high arches (Sever disease), worn-out or unsupportive shoes
• in pitchers, high pitch counts, curveballs and pitching for more than one team

Boys have historically been affected more often, but rates in girls have risen with greater sports participation. Girls tend to be affected a year or two younger because they enter puberty earlier.

Diagnosis

Apophysitis is usually diagnosed by examination. The doctor will press on the growth center to find the tender spot, check flexibility, and watch your child walk, squat or hop.

X-rays are not always needed. They may be used to:

• rule out a stress fracture, bone cyst, infection or tumor when symptoms are unusual
• look for an avulsion fracture, where the tendon pulls a piece of the apophysis off
• assess the inner elbow in throwing athletes

Ultrasound or MRI is reserved for unclear cases.

Treatment

The goal is to reduce stress on the growth plate enough for pain to settle while keeping the child active.

Activity changes

• Reduce, rather than always stop, painful activity. A practical rule is that pain during sport should stay mild (no more than 3 out of 10) and be gone by the next morning.
• Swap high-impact training for cycling or swimming during flare-ups.
• Follow pitch-count and rest-day guidelines for young pitchers. Little League elbow often needs a complete break from throwing for 4 to 6 weeks.

Symptom relief

• Ice for 15 to 20 minutes after activity.
• Acetaminophen (paracetamol) or ibuprofen for pain, following the label dose. Do not give aspirin to children or teenagers.
• Knee straps that sit on the patellar tendon can ease Osgood-Schlatter pain.
• Heel cups or cushioned heel pads and supportive shoes for Sever disease.

Stretching and strengthening

A physical therapist can teach a program targeting the tight muscles: calves for heel pain, quadriceps and hamstrings for knee pain, forearm flexors for elbow pain, plus hip and core strengthening. Daily stretching is the most useful long-term measure.

What is rarely needed

Casts and immobilization are occasionally used for a few weeks when pain is severe. Surgery is rare and mainly used for displaced avulsion fractures or, in adulthood, for a painful loose bone fragment left after Osgood-Schlatter disease.

Outlook

Most children recover within weeks to months with load management. Symptoms can flare with each growth spurt and disappear once the apophysis fuses, typically by 14 to 16 in girls and 16 to 18 in boys. In Osgood-Schlatter disease the bony bump below the knee often remains, and a small number of adults have discomfort when kneeling.

Prevention

• Increase training volume gradually, by about 10% per week.
• Encourage at least 1 to 2 rest days a week and 2 to 3 months off a single sport each year.
• Build stretching into warm-ups and cool-downs, especially during growth spurts.
• Replace worn sports shoes and use appropriate footwear for the surface.

Frequently asked questions

What are the causes and symptoms of apophysitis?

Apophysitis is caused by repeated pulling of a tendon on a growth center in a growing child, usually during running, jumping or throwing sports and growth spurts. Symptoms are pain and tenderness over a specific bony point, sometimes with swelling, that worsen with activity and ease with rest.

Is apophysitis the same as Osgood-Schlatter disease?

Osgood-Schlatter disease is one type of apophysitis, affecting the bony bump below the knee where the patellar tendon attaches. Other types affect the heel (Sever disease), the bottom of the kneecap, the inner elbow, the foot and the pelvis.

How long does apophysitis take to heal?

A flare usually settles within 2 to 8 weeks with reduced activity, ice and stretching. Symptoms may come and go during growth and fully stop once the growth plate fuses in the mid to late teens.

Can my child keep playing sports with apophysitis?

Often yes, with adjustments. Children can usually keep playing if pain stays mild during activity and is gone by the next day. If they limp, cannot finish practice, or pain persists, reduce training and see a doctor or physical therapist.

Does apophysitis cause long-term damage?

Rarely. Most children recover fully once growth finishes. A permanent bony bump below the knee is common after Osgood-Schlatter disease, and a few adults have kneeling pain. An avulsion fracture, where the tendon pulls off a piece of bone, may need specific treatment.