Iselin’s Disease: Apophysitis of the Fifth Metatarsal Base in Adolescent Athletes

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Township, MI. Last updated April 2026.

Iselin’s disease — traction apophysitis at the growth plate of the fifth metatarsal base caused by repetitive pulling of the peroneus brevis tendon — is a pediatric overuse injury producing lateral foot pain at the base of the fifth metatarsal in active adolescents aged 8–15 years. It is frequently misdiagnosed as a Jones fracture or tuberosity avulsion fracture — a critical distinction, since Iselin’s disease is a traction injury to the growth plate (normal developmental variant when asymptomatic) that is treated conservatively, not surgically.

Anatomy, Presentation, and Diagnosis

Anatomy: the fifth metatarsal base apophysis is a secondary ossification center that appears radiographically between ages 8–12 in girls and 10–14 in boys; the peroneus brevis tendon attaches to this apophysis; repetitive eversion forces during running and jumping create traction stress at the growth plate before it fuses (typically by age 15–16). Clinical presentation: lateral foot pain at the base of the fifth metatarsal; onset insidious or after an acute inversion injury; local tenderness over the apophysis; worsened by activities involving foot eversion (running, soccer, gymnastics); examination distinguishes from ankle sprain (more distal and anterior pain). X-ray: the apophysis appears as a parallel crescent of bone at the base of the fifth metatarsal — parallel orientation differentiates it from fractures (fractures are transverse). Critical differential diagnosis: Jones fracture (transverse fracture at the metaphyseal-diaphyseal junction — Zone 2 — perpendicular to the metatarsal shaft on X-ray); tuberosity avulsion fracture (Zone 1 — transverse, at the tuberosity); both fractures require different management from Iselin’s disease.

Treatment

Conservative (virtually all cases): activity modification — reduce or eliminate running and jumping for 4–6 weeks; walking boot for significant pain or inability to bear weight; physical therapy for peroneus brevis stretching and hip/core strengthening to reduce eversion stress; gradual return to sport after pain resolution. Prognosis: excellent — apophysis fuses by age 15–16 and the condition resolves completely with skeletal maturity; chronic cases (symptomatic for >3 months) respond to longer periods of activity modification; surgical excision of the apophysis is almost never required. Parent/athlete education: reassurance that this is a normal developmental process and not a fracture is important — distinguishing Iselin’s disease from a fracture reduces unnecessary immobilization and anxiety. Dr. Biernacki at Balance Foot & Ankle differentiates Iselin’s apophysitis from fifth metatarsal fractures on clinical examination and X-ray at our Bloomfield Township and Howell offices. Call (810) 206-1402 for pediatric foot care.

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Differential Diagnosis: What Else Could It Be?

Not every case of jones fracture (5th metatarsal base) is straightforward. In our clinic we routinely rule out three look-alike conditions before confirming the diagnosis. If your symptoms don’t match the classic presentation, one of these may explain the pain — which is why physical exam matters more than self-diagnosis.

Condition	How It Differs
Pseudo-Jones / avulsion fracture	Fracture proximal to metaphyseal-diaphyseal junction; heals faster with conservative care.
Peroneal tendonitis	Tenderness along the tendon sheath, not bone; no fracture on X-ray.
Cuboid syndrome	Pain slightly proximal on lateral column; no cortical disruption on imaging.

Red Flags — When to See a Podiatrist Now

In Our Clinic: What We See

In-Office Treatment at Balance Foot & Ankle

If home care isn’t resolving your athlete’s foot, a visit with a board-certified podiatrist is the fastest path to accurate diagnosis and a personalized plan. At Balance Foot & Ankle Specialists, Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin offer appointments at both our Howell and Bloomfield Township offices. We perform on-site diagnostic ultrasound, digital X-ray, conservative care, advanced regenerative treatments, and minimally invasive surgery when indicated.

Call (810) 206-1402 or request an appointment online. Most insurance plans accepted, including Medicare, Blue Cross Blue Shield, Aetna, Cigna, and United Healthcare.

Frequently Asked Questions

When should I see a podiatrist?

See a podiatrist for any foot or ankle pain that persists more than 2 weeks, doesn’t improve with rest, limits your daily activities, or is accompanied by swelling, numbness, or skin changes. People with diabetes or circulation problems should see a podiatrist regularly even without symptoms.

What does a podiatrist treat?

Podiatrists diagnose and treat all conditions of the foot, ankle, and lower leg including plantar fasciitis, bunions, hammertoes, toenail problems, heel pain, nerve pain, diabetic foot care, sports injuries, fractures, and foot deformities — both surgically and non-surgically.

What can I expect at my first podiatry visit?

Your first visit includes a full medical history, physical examination of your feet and gait, and in-office diagnostic imaging if needed (X-rays, ultrasound). We’ll discuss your diagnosis and create a plan tailored to your foot type. Most visits take 30–45 minutes.

Need Treatment at Balance Foot & Ankle?

Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin see patients at our Howell and Bloomfield Township offices.

Book Online or call (810) 206-1402

Most Common Mistake We See

The most common mistake we see is: Waiting too long before seeking care. Fix: any foot pain lasting more than 4 weeks, or any sudden severe symptom, deserves a professional evaluation rather than more rest.

Warning Signs That Need Same-Day Care

Frequently Asked Questions

What causes this condition?

Causes include mechanical stress, biomechanical imbalance, age-related changes, and sometimes systemic disease. Our clinical exam plus imaging identifies the specific driver.

Can it go away on its own?

Mild cases sometimes resolve with rest and supportive footwear. Persistent symptoms past 4-6 weeks rarely resolve without active treatment.

Is surgery required?

Most patients resolve with non-surgical care. Surgery is reserved for refractory cases or structural deformity.