Foot and ankle pain in children is common, with up to 50% of children experiencing musculoskeletal pain at some time. The most frequently affected sites are the foot and ankle as they are the initial contact points with the ground during walking and running, and are required to adapt to different terrains while supporting the weight of the body. Pain may occur as a result of trauma (either acute or repetitive), infection or systemic disease, or it may be due to an underlying mechanical cause. The burden of foot and ankle pain must not be underestimated, a Swedish study found that 10% of children presenting to a rheumatology clinic did so because of foot or ankle pain, while two further studies reported that 4% of medical clinic visits by children were for foot related problems. Chronic or recurrent pain may lead to restrictions in activity and participation, with potential consequences on physical and psychological health. The effect of foot pain on overall health and quality of life is recognised to be at least equivalent to that of higher profile conditions such as rheumatoid arthritis and type 2 diabetes. Despite this, there remains a paucity of information on the aetiology and impact of paediatric foot and ankle pain. At all stages healthcare for children is improved when relevant research evidence is used, however to date research into foot and ankle pain in children has been limited, possibly due to the complex and evolving nature of the lower limb. This is reflected by a lack of high quality clinical trials and paucity of validated outcome measures to capture the impact of foot and ankle conditions on children’s lives. Published research tends to focus on pathologies with clear and immediate effects on child health, the fact that little is known on the consequences of minor foot complaints does not mean they are insignificant. A young person’s feet are the foundation for adult function and health. It is imperative that healthcare providers and researchers better understand normal foot and ankle development, in order to differentiate between variants of healthy development and foot problems which may benefit from intervention. Knowledge of paediatric lower limb anatomy and biomechanics is currently sparse compared to the adult, with most musculoskeletal and sports medicine textbooks primarily providing information on conditions affecting the adult foot. This is a limiting factor for all health professionals involved in child healthcare, particularly as assessment of foot and ankle problems in children must take into account normal variations due to growth and development.
Definition of Foot and Ankle Pain in Children
Foot and ankle pain in children is a common symptom and is often treated as a clinical entity. Pain can be purely subjective, and its presence can be a normal part of a child’s musculoskeletal development. As a guide, pain is considered chronic if it has been present for greater than three months. It may also be associated with activity avoidance, limping or an undesirable change in behavior. Often the pain is not site specific and is poorly localized. Typically no direct cause can be identified as there is frequently no history of trauma and systemic symptoms are uncommon. In order to define the problem further, we can broadly categorize pain into two groups: traumatic pain and insidious onset pain. Traumatic pain is usually the result of a recognizable injury such as an ankle sprain. This is associated with pain, swelling and limping at the time of injury and can often be managed as an acute injury. An x-ray may be indicated if there is significant pain in a bony area, or if symptoms do not improve in the expected time frame. If the x-ray is normal symptoms will usually settle with simple management such as PRICE and activity modification. Osgood Schlatter disease and Sever’s disease are specific examples of traction apophysitis which is similar to traumatic injuries in presentation and prognosis.
Importance of Identifying Developmental Issues
The child’s foot is not a small adult’s foot. The children’s foot is a developing structure, and deformities and developmental problems may not be obvious to the untrained eye. The assessment of the child’s foot may be simple, for a child with flat feet, or it may be a complex process when dealing with a systemic disease process or a child with multiple problems. The child’s foot must be assessed in the context of the child’s lower extremity development. A foot problem in a child may be a sign of a more generalized developmental problem. Conversely, a deformity in the foot and ankle may cause a gait abnormality that can negatively affect the overall developmental process. An understanding of that process is crucial. The assessment of foot deformities in children requires an understanding of the normal development of the foot. This understanding will help to determine whether the deformity is a flexible problem that can be observed over time without harming the child, or a problem that must be addressed because it will lead to a fixed deformity.
Common Causes of Foot and Ankle Pain in Children
Another common site for infection following injury is in the hollow just below the ankle on the outer side of the foot. Injuries such as sprains and strains at the ankle are also common and usually will be obvious in the amount of pain and swelling which develops over a short period of time. Many of these injuries are minor, but it is important that any injury which causes more than a slight limp in walking is investigated and treated by a doctor to avoid any long-term problems.
Most activities that children participate in can cause injury and trauma to the foot and ankle. Football and other running sports carry a high risk of injury in the form of sprains, strains, or breaks to the bones. However, one of the most common foot injuries in children is the result of a seemingly minor incident such as kicking a piece of furniture. This often leads to a toenail injury causing blood to collect under the nail (subungual hematoma). Left untreated, this can cause the nail to fall off and can be very painful. The injury can also cause an infection in the skin surrounding the nail. Symptoms include pain, swelling, and redness along the edge of the nail, where in severe cases an abscess may form.
Causes of pain in children’s feet and legs can be categorized into several different types. Some are due to obvious visible changes or injury, while sometimes pain is the result of a growth-related condition or developmental problem.
Growth-related Issues
Systemic disease Juvenile Idiopathic Arthritis (JIA) can produce significant joint destruction and long-term deformity if not managed correctly. The potential severity of this condition makes it essential to diagnose and start treatment early. JIA affects the synovium of joints. In the foot and ankle, this can produce painful swelling of a joint which may be mistaken for an acute injury. Acute JIA of the subtalar and talo-navicular joints can produce an atraumatic flatfoot through tarsal joint synovitis. Long-term destruction of the joint surface can result in significant arthritis with the development of valgus hindfoot and bunions due to rearfoot instability. High-dose anti-inflammatory medication over a long period of time can weaken the physis and lead to potential leg length discrepancy and altered angulation of the knee. Physicians must be vigilant to monitor all of these potential problems so that appropriate orthotic and/or surgical management can prevent structural deformity. Similarly, careful management of other pediatric inflammatory arthropathies and systemic diseases which directly affect the musculoskeletal structure is essential to prevent pain and long-term disability in the growing child’s foot and ankle.
Injury and Trauma
Injuries to the foot and ankle can occur in many settings, with sports and physical activities being the most common. Injuries can be as mild as an ankle sprain or as severe as a Salter Harris III or IV fracture of a growth plate. Ankle sprains are very common in children, often occurring during activities that involve running, jumping or changes in direction. These activities can “stretch out” ligaments, causing ankle instability for prolonged periods of time. Ankle instability can lead to chronic ankle pain and a feeling of “giving way” of the ankle. Recurrent ankle injuries can also cause a condition called “anterolateral impingement” where the talus bone repeatedly hits the front of the ankle joint, causing pain and decreased motion of the joint. Sports that involve jumping can cause a wide variety of injuries to the growth plate of the distal tibia (shin bone) and the growth plate of the calcaneus (heel bone). High impact injuries can cause growth plate fractures which if severe enough, can alter the normal growth of bone, leading to deformity and arthritis. Any injury to a growth plate has the potential to disrupt normal bone growth and can cause limb length discrepancies or angular deformities of the bones. A thorough history and physical examination are crucial to determine the cause of foot and ankle pain in a child who has sustained an injury. Advanced imaging studies may be needed to confirm the diagnosis and to help guide treatment.
Structural Abnormalities
Structural abnormalities are common issues arising from the development of the child’s foot. Structural abnormalities are sometimes regarded as the development of a flat foot. When a child has a flat foot, it simply means that there is no arch present and at times it can appear like an inversion of the foot. Presently, one of the most common known dangers to flat foot is the predisposition to posterior tibial tendonitis. This is a problem that usually arises in adults and the long-term effects of having a child with a flat foot are still quite unknown. Pain is usually a sign of increased stress and tightness on the tendon, giving it the common name of ‘policeman following the army’ tendonitis. If the tendonitis persists, the condition can further develop into adult acquired flat foot and this produces even more stress to tendons and ligaments around the foot and ankle. Another structural abnormality related to pain is rotational deformities of the lower limb, mainly occurring at the hip and tibia. One common deformity is intoeing, where the child walks with the feet pointing inwards. This usually is a result of metatarsus adductus, internal rotation of the hip, or femoral anteversion. Usually, these do not cause pain, however, in cases of internal torsion of the tibia, the twisting of the bone results in excessive internal bending forces to the tibia and its eventual overuse. This condition may cause shin pain in the child and may be mistaken for ‘growing pains’ in the younger child.
Diagnostic Approaches for Foot and Ankle Pain in Children
The physical examination should follow the history and be tailored to the areas of complaint and to the differential diagnosis suggested by the history. Observation of limping or guarding is an important first step. In regards to gait, it is important to determine whether the abnormality is the result of pain versus weakness versus a primary neuromuscular disorder. A comprehensive study of the musculoskeletal examination is beyond the scope of this article, focusing examination of specific joint symptoms will be discussed in other sections.
The first step in evaluating a child with foot and ankle pain is to establish a concise and clear history. The history should establish the onset of pain symptoms, the location and character of the pain, any antecedent trauma, any systemic symptoms and the overall impact of the symptoms on the child. A pain diagram may be helpful to determine the location and radiation of symptoms. Stepwise swelling in the setting of pain that is worse at night and wakes the child from sleep should raise the index of suspicion for a neoplasm or infection. Inflammatory joint pain will have a characteristic morning stiffness lasting at least 1 hour.
Medical History and Physical Examination
Information about the onset of pain, its duration, exacerbating and relieving factors, and the type of pain (ache, stabbing, burning) can provide useful diagnostic clues. It is not unusual for parents to report that their child has had pain for years, but when questioned further, they may reveal that the pain has not been continuous but has occurred intermittently, particularly after strenuous activity. The pain may then resolve with rest, and when better, the child has been able to participate in the same activities without pain. This history is often typical of a stress-related overuse injury.
Generally, a comprehensive medical history and physical examination will provide the clinician with a wealth of valuable clinical information. This is the easiest, most efficient, and sometimes most sophisticated diagnostic tool available. So often it will lead to diagnosis without further need for testing. Unfortunately, in today’s clinical environment, where time constraints can limit detailed personal contact between the treating clinician with patients and their parents, this important component of the diagnostic process is often neglected. This can increase the risk of incorrect diagnosis and can lead to unnecessary, perhaps harmful therapy or surgical intervention.
Imaging Techniques
Accuracy of the different imaging techniques for specific diagnoses has not been well established and the ability to predict outcome or response to treatment is often more important than reaching a precise diagnosis. In general, it is helpful if imaging techniques can be used to confirm clinical findings so that any changes can be monitored and a treatment endpoint defined.
In comparison with adults, MRI is often more essential in children because bone injury is less common. An MRI scan provides excellent detail for both bone and soft tissues and is particularly useful for assessing joint, ligament, tendon, and epiphyseal injuries. However, the relatively high cost and the need for a cooperative and still child, heavy sedation, or general anesthesia, mean that the decision to use MRI needs to be carefully weighed. This is particularly relevant for a self-limiting condition. Random comparison with plain radiographs has shown that important bone abnormalities can be missed on MRI. Open low field MRI machines are increasingly available and can be used for some examinations without sedation.
Ultrasonography is similar to radiography in that it is a cheap and quick method, it does not use ionizing radiation, and can be used to monitor healing. It is particularly useful for assessing synovitis, effusion, tendonitis, and the state of other soft tissues and can be used for guided injections. Ultrasonography has limitations, however; the image quality can be operator dependent and because it is not good for assessing bone. Random comparison with MRI has shown that ultrasonography can miss clinically important findings.
Radiography is obviously useful for assessing bone; it is relatively cheap and quick and can be used to monitor healing. However, the assessment of bone alignment requires comparison with the uninvolved contralateral limb or old radiographs. Radiography is limited in its ability to assess the articular surfaces in children because the secondary centers of ossification are not yet present.
General diagnostic imaging techniques, including radiography, computed tomography (CT), and magnetic resonance imaging (MRI), are commonly used to assess musculoskeletal problems in children. Medical ultrasound is an evolving technology that is increasingly being used in the assessment of musculoskeletal conditions in children. Each modality has strengths and weaknesses that need to be understood in order for the most appropriate technique to be used, both in terms of the nature of the condition under investigation and its expected duration, the age of the child, the importance of minimizing ionizing radiation, and the local expertise and equipment available.
Laboratory Tests
Routine blood work including a complete blood count and general chemistry panel is generally normal in children with isolated foot and/or ankle pain and has little value in the workup of these patients.
An HLA-B27 gene test is relatively specific to spondyloarthropathies, although a negative result does not exclude disease and a positive result needs to be correlated with the entire clinical picture. This test can be useful in children with sacroiliitis or those with a family history of an HLA-B27 associated disease.
C-reactive protein is another general marker of inflammation which is elevated in many systemic inflammatory conditions. As with an elevated ESR, an elevated CRP is nonspecific and has only minimal value in the differential diagnosis of foot and/or ankle pain.
ESR also tends to be elevated in children with osteomyelitis, although the focus of their symptoms and systemic symptoms such as fever would generally help to differentiate this from other causes of foot and/or ankle pain.
Erythrocyte sedimentation rate (ESR) is a general marker of inflammation and has been found to be elevated in children with enthesitis related arthropathy (ERA) associated with juvenile idiopathic arthritis. Unfortunately, the specificity of this finding is low, as evidenced in a study by Stoll et al. which demonstrated that almost 20% of children with patellar pain had an elevated ESR at the initial visit.
The majority of the laboratory workup for pediatric patients with foot and/or ankle pain focuses on the exclusion of systemic inflammatory arthropathies rather than defining a specific diagnosis. As a result, the utility of these tests is variable.
The discussion of laboratory tests is fairly straightforward, as there is relatively little literature available on this subject in the pediatric population. As a result, this section will be interspersed with findings from the adult literature and comments about their application to the pediatric population.
Treatment and Management of Foot and Ankle Pain in Children
A widely researched and common juvenile foot abnormality is flexible flat foot. It has been suggested that it is physiologically normal in the developing child due to the presence of subcutaneous fat, ligamentous laxity, and generalized joint hypermobility. Weightbearing forces can cause the medial arch to collapse with the hindfoot evert. It is often asymptomatic in the early years, but if it persists, treatment may be required to prevent pain and dysfunction in the future. Self-limiting cases are likely to correct with age; therefore, treatment is targeted at symptomatic relief. Shock-absorbing orthotic therapy with a medial arch support has been shown to improve symptoms of pain and fatigue. These orthoses are designed to absorb and dissipate the ground reaction forces that are transmitted through the lower limb and are effective in reducing symptoms in symptomatic flexible flat foot.
Treatment and management of foot and ankle pain in a child is centered on the correction of identified abnormalities. Interventions are targeted at reducing pain, preventing it from recurring, and restoring normal function of the lower limb. The podiatric physician should select methods of treatment with these goals in mind. Due to the increased load through the lower limb as the child grows and develops, it is imperative that treatment is implemented in a timely fashion to prevent long-term effects or complications. With increasing development of the lower limb, the child’s foot is more likely to be susceptible to deformity or developmental anomalies. Therefore, in some cases, it is appropriate to monitor lower limb development with the expectation that the deformity will self-correct with growth. In cases where pain is present or the deformity results in a functional abnormality, intervention may be necessary.
Non-surgical Interventions
Non-surgical interventions are often very successful in treating many of the conditions outlined in section 3. Physiotherapists and podiatrists are well equipped to offer a variety of treatments according to the nature of the condition. Flexibility or strength imbalances as contributing factors in musculoskeletal pain are amenable to targeted exercise prescription. This may involve a home exercise program or supervision on a regular basis. A key to this approach is identification of the specific area or muscle group requiring intervention. This may be achieved through a variety of means, one of which is real-time ultrasound imaging which has been shown to be reliable for assessment of muscle activity in children. A variety of equipment and manual techniques exist for the improvement of muscle flexibility and soft tissue mobility. These types of treatments are especially effective due to the ability to easily modify tissue stress. Often the same effect cannot be achieved in a child through manual techniques that are employed for adults. The prescription of modification of activity or load is an important consideration for any treatment. With pain a common factor in many of these conditions, it may be necessary to initially offload painful structures. This may be achieved through rest from aggravating activities, crutch walking, or the use of orthotic or footwear modifications. An evidence-informed approach should be taken to the recommendation of offloading strategies due to concern for the effects of a change in skeletal development. Orthotic devices can be especially useful in cases where malalignment or structural deformity is a factor in musculoskeletal pain. The ability to modify the design of an orthotic and the growth of a child presents both a challenge and a potential long-term solution to many of these conditions. A periodic review will often be necessary for the aforementioned interventions due to the changing nature of the child’s condition and to evaluate the effectiveness of treatment.
Foot and ankle pain in growing children is a common problem, worthy of special consideration. It is important to remember that children are not simply little adults. They are constantly growing and, during this time, there are many cartilaginous areas in their bones which are susceptible to overuse and traumatic injuries. It is now widely recognized that the occurrence of adult musculoskeletal disorders (MSD) may have origins in childhood or adolescence. Identification of these disorders in the growing child and understanding the factors involved are an essential first step in any preventative or conservative management.
Surgical Options
Treatment of painful pediatric flatfoot has historically been confined to conservative options such as orthotic devices and shoe modifications. When conservative measures fail, surgery may be indicated, and this decision is influenced primarily by the degree of pain and functional disability. Combining these considerations with an understanding of the specific developmental flatfoot deformity and its natural history is essential in making the decision to proceed with surgical intervention. Flexibility is a key characteristic of the pediatric flatfoot, and the rate of progression to adult symptoms is unknown. It is likely that many adult flat feet have their origins in childhood, but there is currently little evidence to predict which flat feet will cause adult disability. Nevertheless, the rigid adult flatfoot is difficult to correct, and interventions to delay or prevent its occurrence may be more successful than attempts to treat the fully developed condition. Pediatric flatfoot is a diverse condition, and surgical procedures should be individualized with the aim of correcting specific deformities. The general aims of surgery are to improve pain and function, to create and maintain a plantigrade foot, and to normalize the alignment of the foot to the lower extremity.
