Fifth Metatarsal Apophysitis is painful irritation and inflammation of the apophysis (growth plate) at the base of the 5th metatarsal (foot bone), where one of the calf muscles inserts. In a child, the bones grow from areas called growth plates. The apophysis of the proximal 5th metatarsal (plural apophyses) lies laterally and is oriented longitudinally parallel to the shaft. Apophysis of the fifth metatarsal base appears on plain radiographs at age 12 for boys and 10 for girls. Through an open incision, surgeons can return your fractured bone into the normal position and fix your fifth metatarsal bone with what is called an intramedullary screw. This screw is run through the marrow cavity in the center of your fifth metatarsal. Most patients can go home the same day after surgery.
Other Names
- Iselin’s Disease
- 5th Metatarsal Apophysitis
- Fifth Metatarsal Apophysitis
Pathophysiology
- General
- Is a benign, painful traction apophysitis or osteochondrosis of the apophysis of the 5th metatarsal tuberosity
- Exclusive to skeletally immature patients
- Generally considered a self-limited disorder
- Often confused for
- Fracture of the base of the fifth metatarsal
Causes
- Peroneus Brevis Tendon (PB Tendon)
- Attaches to the tuberosity of the fifth metatarsal (apophysis)
- Caused by repetitive microtrauma at the site of attachment
- Can result in partial/complete avulsion of the apophysis and inflammation
- Associated with athletics where repetitive motion occurs
- Especially sports that stress the forefoot such as dance, ballet, skating
- Sports that require jumping and running
- Fifth Metatarsal
- The secondary ossification center appears as a small fleck oriented slightly oblique to the metatarsal shaft
- Located on the lateral aspect of the tuberosity of the fifth metatarsal
- Peroneus brevis inserts over this apophysis before skeletal maturity
Risk Factors
- Sports
- Dance
- Ballet
- Roller skating
Differential Diagnosis
- Jones Fracture
- 5th Metatarsal Avulsion Fracture
- 5th Metatarsal Stress Fracture
- Os Vesalianum
Differential Diagnosis Foot Pain
- Fractures & Osseous Disease
- Traumatic/ Acute
- Talus Fracture
- Calcaneus Fracture
- Traumatic Navicular Fracture
- Cuboid Fracture
- Cuneiform Fracture
- Metatarsal Fracture
- Fifth Metatarsal Fracture
- Toe Fracture
- Hallux Sesamoid Fracture
- Stress Fractures
- Navicular Stress Fracture
- Metatarsal Stress Fracture
- Other Osseous
- Tarsal Coalition
- Accessory Navicular Syndrome
- Traumatic/ Acute
- Dislocations & Subluxations
- Toe Dislocation
- Lisfranc Injury
- Chopart Complex Injury
- Cuboid Syndrome
- Muscle and Tendon Injuries
- Posterior Tibial Tendon Dysfunction
- Peroneal Tendonitis
- Tibialis Anterior Tendinopathy
- Flexor Hallucis Longus Tendinopathy
- Ligament Injuries
- Plantar Fasciopathy (Plantar Fasciitis)
- Turf Toe
- Plantar Plate Tear
- Spring Ligament Injury
- Neuropathies
- Mortons Neuroma
- Tarsal Tunnel Syndrome
- Joggers Foot (Medial Plantar Nerve)
- Baxters Neuropathy (Lateral Plantar Nerve)
- Arthropathies
- Hallux Rigidus (1st MTPJ OA)
- Gout
- Toenail
- Subungual Hematoma
- Subungual Exostosis
- Nail Bed Laceration
- Onychocryptosis (Ingrown Toenail)
- Onychodystrophy
- Paronychia
- Onychomycosis
- Pediatrics
- Fifth Metatarsal Apophysitis (Iselin’s Disease)
- Calcaneal Apophysitis (Sever’s Disease)
- Freibergs Disease (Avascular Necrosis of the Metatarsal Head)
Diagnosis
- History
- The athlete is typically 10 to 16 years old
- Insidious onset with no history of trauma
- A most common symptom is a pain in the lateral part of the foot or around the base of the fifth metatarsal
- Worse with activity and improves with rest
- May have difficulty or pain with wearing shoes
- Patients may have 3-6 months of symptoms before presentation
- Physical Exam: Physical Exam Foot
- Swelling and erythema over the base of 5th metatarsal
- Tenderness over the base of 5th metatarsal tuberosity
- Pain with resisted eversion and extreme plantarflexion/inversion
- On gait exam, may favor the medial side of the foot
- Special Tests
Oblique foot radiograph showing elevation, fragmentation and sclerosis of the apophysis with overlying soft tissue swelling consistent with 5th metatarsal apophysitis.[3]
Radiographs
- Standard Radiographs Foot
- Apophysis saw on oblique view
- Findings
- Fragmentation
- Widening or enlargement of the apophysis
- Cystic changes around the apophysis
- Widened chondro-osseous junction
- Normal apophysis
- Fleck of bone parallel to the long axis of 5th metatarsal (≠ avulsion fracture),
- Visible in girls (9-11), boys (11-14)
MRI
- Findings
- Edema over the unfused apophysis
- Mild to moderate marrow edema in the adjacent fifth metatarsal
Bone Scintigraphy
- Generally not indicated or performed
- Findings
- Increased uptake over the apophysis
Treatment
Nonoperative
- Indications
- All cases
- Activity modification
- Discontinue offending activity
- Rest from sports
- Immobilization/ weight-bearing status
- Cast immobilization if persistent pain despite other non-surgical management
- May require crutches
- Physical Therapy
- Can begin after pain, tenderness is completely resolved
- Stretching of peroneal and calf muscles
- Ice Therapy
- Foot Orthosis
- A small lateral elevation or a lateral wedge ensures reduced stress on the peroneal muscles during daily activities
- Prevention
- Maintain calf, peroneal, and ankle flexibility and strength
- Check shoe size during rapid periods of growth
Operative
- Indications
- Persistent pain despite exhaustive nonoperative treatment
- Nonunion over the apophysis
- Persistent widening of radiolucent lines after 3-6 months
- Operative
- Surgical excision
