Foot and toe injuries

A child’s foot is significantly more cartilaginous than an adult foot, making foot fractures an uncommon injury in children. Foot fractures constitute about 5-8% of paediatric fractures. Evaluation and management of a paediatric foot injury requires an understanding of paediatric anatomy, a careful history, clinical examination, and potentially radiography.

Normal anatomy

The foot is anatomically divided into 3 sections: hindfoot, midfoot and forefoot.

The hindfoot includes the talus and calcaneus. The inferior surface of the talus is more prone to avascular necrosis due to its retrograde blood supply. The part of the calcaneus most prone to fracture is its large posterior facet.

The midfoot includes the navicular, cuboid and the three cuneiform bones.

The forefoot includes the metatarsals and phalanges.

Evaluation of foot injuries

History

The following specific enquiries should be made about the injury:

• The mechanism of injury (high/low velocity, twisting, compression, direct blow)
• Characteristics of pain (worse at the time of injury vs late onset)
• Location of pain
• Consistency and plausibility of the history, excluding concerns about non-accidental injury
• The effect of the injury on the child (limping, the distance the child can move)
• The efficacy of pain relief

Examination

Clinical examination should be tailored to the history.

Look

For external skin abrasions or obvious open fractures.

Feel

Palpation of the bones: tarsals, metatarsals, toes and the base of the 5^th metatarsal.

Palpation for tenderness along the ligaments: deltoid ligament on medial side and anterior talofibular, calcaneofibular and posterior talofibular ligaments on the lateral side.

Move

The active movement should be followed by passive movement as much as pain allows.

The usual range of movements are: subtalar eversion (15-20°), subtalar inversion (35-40°), forefoot adduction (20°), forefoot abduction (10°), 1^st metatarsal phalangeal (MTP) flexion (45°), 1^st MTP extension (70-90°) and free motion of lesser toes.

Neurovascular examination

Two pulses: dorsalis pedis and posterior tibial.

Five sensory nerves: saphenous (medial calf and hindfoot), superficial peroneal (dorsum of the foot), deep peroneal (1^st dorsal webspace), sural (lateral foot) and posterior tibial nerve (plantar foot and heel).

Imaging

The Ottawa foot rules can be applied to children. The rules have 97-100% sensitivity in paediatric injury investigation. According to the rules, x-rays of the foot are required if the child is unable to weight bear both immediately after the injury and in the ED, plus bony tenderness over the base of 5th metatarsal or the navicular.  

Accessory ossicles

Accessory foot ossicles can cause pain as a result of stress injuries. The navicular ossicles, arise either on the medial side of (os tibiale externum) or on the lateral tubercle of the navicular bone (os trigonum).

Os tibiale externum

This is an ossification centre that arises at the site of the tibialis posterior tendon on the medial side of the navicular bone. It becomes an accessory bone when it fails to fully ossify.  It is present in 4-14% of patients.

The usual presentation is in adolescence when the patient has pain from overuse, especially in athletes.

Examination may reveal pes planus (flat foot). This happens as the tibialis posterior tendon, maintaining the medial longitudinal arch, attaches to the accessory bone rather than the navicular bone.

Investigations include plain films and, occasionally, MRI scan.  

Treatment is initially conservative with orthotics and casting. The ossicle is excised if these measures fail to resolve the pain.

Os trigonum

This is present in 10-25% of the population. It is often associated with heel pain in ballet dancers due to repetitive microtrauma.

Hindfoot fractures

These are rare, constituting only 0.008% of all paediatric fractures. Children usually present after falling from height or after a motor vehicle injury. The talus can be fractured in multiple places including avulsion fracture.

‘Snowboarder’s fracture’ is a fracture of the lateral process of the talus. The mechanism of injury involves dorsiflexion and inversion.

Do not miss: Snowboarder’s fractures are often misdiagnosed as an ankle sprain. If not evident on x-ray, a CT or MRI should be performed if there is clinical suspicion. Think carefully about the mechanism.

Calcaneus fractures typically occur due to axial loading and are frequently associated with vertebral compression fractures. Radiography should include AP, lateral and axial views. The axial view offers a better view of the fracture.

Treatment of talus and calcaneus fractures is dependent on the degree of displacement.

• Non or minimally displaced avulsion fractures, or extra-articular fractures should be managed in a posterior short leg splint and should be non–weight bearing with crutches for 3 to 4 weeks.
• Displaced fractures require reduction, by an orthopaedic surgeon, followed by immobilisation with a splint or cast. Severely displaced, comminuted or intra-articular fragments may require ORIF.

Midfoot fractures

These are also rare fractures and usually result from severe blunt injury. Most fractures are avulsion or stress fractures and are associated with other injuries.

Treatment depends on the severity of displacement of the fracture and associated injuries.

• Non or minimally displaced fractures (the majority of these fractures) can be treated with a walking cast.
• Displacement of the fracture fragment greater than 2mm should be managed with reduction and stabilisation before immobilisation.

Midfoot fractures have minimal long term sequelae.

Forefoot fractures

Forefoot fractures represent about 60% of paediatric foot fractures and can result from either direct or indirect trauma. They are easily missed: about 41% are missed due to high energy trauma causing other significant injuries.

Lisfranc fracture

Lisfranc fractures occur due to axial loading with forced plantar flexion (commonly seen in bicycle or horseback riders where a foot gets caught in a pedal or stirrup) or with a crush injury.

Clinical examination

• Tenderness over the dorsum of the foot with swelling and inability to bear weight.
• Plantar bruising is a consistent sign and if present should raise suspicion of the injury.  

Diagnosis is made with a weight bearing x-rays (as the fracture may not be evident on non-weight bearing views) – AP, lateral and oblique radiographs of the foot. The normal alignment of the foot should have the 2^nd metatarsal aligning with the intermediate cuneiform on the dorsoplantar view and the 3^rd metatarsal aligning with the lateral cuneiform on the oblique view. The Lisfranc ligament connects the cuneiforms to the 2^nd metatarsal. Disruption of this ligament leaves the foot unstable and hence it is an important not to miss this injury. Due to the ligament attachment, there is often associated fracture of the bases of the 1^st or 2^nd metatarsal in a Lisfranc injury.

Treatment depends on the degree of severity of the injury.

• Partial tears with < 2mm malalignment require immobilisation or a walking boot for 4-6 weeks. The patient should be referred to orthopaedic surgeons within 3-5 days due to the high rate of late complications.
• More severe injuries require operative treatment with internal fixation.

There is a high rate of residual pain in children with a Lisfranc injury.

Metatarsal fractures

Metatarsal fractures are associated with athletic activity and are becoming more common. The 5^th metatarsal is the most commonly fractured metatarsal in paediatric patients. It can result from twisting, repetitive stress or direct trauma. 1^st and 5^th metatarsal fractures can be isolated whereas 2^nd-4^th metatarsal fractures often occur along with other metatarsal fractures. It is a frequently missed fracture on a radiograph.

Children younger than 5 years of age are more likely to be injured by a fall from height and fracture the 1^st metatarsal. Older children are more likely to fracture it from falling from a standing position, during sports and tend to fracture the 5^th metatarsal.

Pseudo-Jones fracture

A Pseudo-Jones fracture is an avulsion fracture of the base of the 5th metatarsal resulting from a twisting injury of the foot. The examination will reveal focal point tenderness. The patient should be immobilised for 3-4 weeks in a weight-bearing cast.

Treat with a short walking boot or hard sole shoe for 6 weeks. Follow-up with orthopaedic surgeons.

Jones fracture

The Jones fracture is a fracture of the metaphyseal-diaphyseal junction at the base of the 5^th metatarsal bone. It is the most common of metatarsal fractures (40%), representing about 25% of all paediatric foot fractures.

Fractures at or distal to the metaphyseal-diaphyseal junction require 6 weeks in a non–weight bearing cast, with crutches. All patients should be referred to orthopaedic surgeons as there is a high incidence of delayed union of the fracture. Many of these patients will require ORIF subsequently.

The apophysis of the base of the 5^th metatarsal appears at age 10 for girls and at age 12 for boys. An unfused apophysis runs longitudinally whereas pseudo-Jones fracture runs transversely.

Toe fractures

Toes fractures are one of the most common fractures in the paediatric population. Phalangeal fractures constitute about 3-7% of all physeal fractures and are usually Salter-Harris I or II injuries. They are more common in boys than girls and are mostly closed in nature.

The patient may present with localised tenderness to the toe, a limp or inability to bear weight. Nail bed bleeding and bleeding from or around the nail fold should prompt the possibility of an open fracture through the nail bed. Alignment, rotation and neurovascular status should be checked.

Fractures of the 2^nd-5^th toes are usually treated by buddy strapping and weight bearing as much as possible. Healing can take up to 3-4 weeks. A hard-soled shoe or walking boot may be used for patient comfort. Follow-ups with orthopaedic surgeons can cease 3 weeks after the injury. If there is possible injury to physis then follow-up should continue for 1-2 years to detect abnormal growth.

The big toe

The big toe plays an important part in bearing weight. Fractures of the big toe are therefore managed slightly differently.  Salter-Harris III or IV fractures of the proximal phalanx of the hallux are often intra-articular.

Urgent orthopaedic consultation for closed or open reduction for K wiring if:

• more than one third of the joint surface is involved or
• displacement is more than 2-3mm

In other cases, toe platform cast or a walking boot is used.

The epiphysis of the proximal phalanx of the 1^st toe is sometimes bipartite, simulating a Salter-Harris III fracture. If there is no tenderness on the 1^st toe, no treatment is indicated.

Phalangeal open fractures require thorough irrigation and debridement in addition to antibiotics to avoid osteomyelitis.  A nail-bed injury to the germinal matrix will require surgical repair.

Long term complications include growth arrest and angular deformities from physeal injury, degenerative joint disease from intra-articular fractures and osteomyelitis from open fractures.

References

Boutis K: Paediatric metatarsal and toe fractures. Up to Date 2019

Boutis, K., 2021. UpToDate. [online] Uptodate.com. Available at: <https://www.uptodate.com/contents/foot-fractures-other-than-metatarsal-or-phalangeal-in-children> [Accessed 4 April 2021].

Boutis, K., 2021. UpToDate. [online] Uptodate.com. Available at: <https://www.uptodate.com/contents/foot-fractures-other-than-metatarsal-or-phalangeal-in-children> [Accessed 4 April 2021].

Eiff, M. and Hatch, R. Fracture management for primary care and emergency medicine. Elsevier.

Halai, M., Jamal, B., Rea, P., Qureshi, M. and Pillai, A., 2015. Acute fractures of the pediatric foot and ankle. World Journal of Pediatrics, 11(1), pp.14-20.

Horner K and Tavarez M, 2016. Paediatric Ankle and Foot Injuries. Clin Pediatr Emerg Med, 17 pp. 38-52

Juliano, P., 2018. Lateral Talar Process Fractures – FootEducation. [online] FootEducation. Available at: <https://footeducation.com/lateral-talar-process-fractures/> [Accessed 4 April 2021].

Malanga, G. and Ramirez – Del Toro, J., 2008. Common Injuries of the Foot and Ankle in the Child and Adolescent Athlete. Physical Medicine and Rehabilitation Clinics of North America, 19(2), pp.347-371.

Metaizeau, J. and Denis, D., 2019. Update on leg fractures in paediatric patients. Orthopaedics & Traumatology: Surgery & Research, 105(1), pp.S143-S151.

Smit, K. Foot Fractures – Phalanx | Pediatric Orthopaedic Society of North America (POSNA). [online] Posna.org. Available at: <https://posna.org/Physician-Education/Study-Guide/Foot-Fractures-Phalanx> [Accessed 4 April 2021].