Porter & Schon: Baxter's The Foot and Ankle in Sport, 2nd ed.

Section 4 - Unique Problems in Sport and Dance

Chapter 23 - Pediatric problems and rehabilitation geared to the young athlete

Dan Kraft,Jerett Zippin


CHAPTER CONTENTS

  

 

Introduction

  

 

Congenital problems

  

 

Developmental problems in young athletes

  

 

Acute injuries

  

 

Pediatric ankle fractures

  

 

Osteochondroses

  

 

Nonarticular osteochondrosis

  

 

Conclusion

  

 

References

Introduction

As young athletes become more active in organized and specialized activities today, sports medicine physicians are diagnosing an increasing number of both acute and overuse injuries in this age group. Many of these injuries involve the foot and/or ankle. These injuries often involve either the apophysis or the epiphysis and require specific treatment and care that is different from that for adults. The growth plates give young athletes a unique set of problems and do not allow physicians to treat the young patients simply as smaller versions of adults. In this chapter we review some of the major foot and ankle problems that are seen clinically in young athletes. The problems are grouped into congenital problems, developmental problems, acute injuries, and problems of osteochondroses. We discuss the approach to rehabilitation under each topic and in particular that which is most applicable to treatment of younger athletes.

 

Congenital problems

Coalitions

Congenital abnormalities often become symptomatic when increased stress, such as intense activity, is applied to the area. Therefore an inactive child may not complain of pain until he or she enters organized sport and the congenital problem may appear to trigger the symptoms. In many congenital problems, the natural history is unmasked with the longer duration and increased intensity of the activity, although the developmental and growth stage actually may be the determining factor in the onset of symptoms. Tarsal coalition is one congenital abnormality that may present in later elementary- and middle school-aged athletes as they begin increasing their participation in organized sports.

Tarsal coalition is a congenital bridging of two or more tarsal bones of the foot, which can be either bony or soft tissue (cartilage or fibrous tissue). The overall incidence of tarsal coalitions has been noted in studies to range from less than 3% to as high as 12.9% of the population.[1] Coalitions can be seen between any two tarsal bones, but the two most common types are calcaneonavicular (bilateral in 60%) and talocalcaneal coalitions (bilateral in 50%).[2]

These athletes typically present when the coalition begins to ossify. In early childhood and at elementary school age, coalition bridging is mostly nonossified, which allows some motion between the bones and keeps these patients typically asymptomatic.[3] Motion becomes restricted when the bridging begins to ossify between 8 and 12 years of age for the calcaneonavicular coalition and between 12 and 16 years for the talocalcaneal coalition. This often is a prime age for middle school and early high school athletes to raise the level of their play and intensity, thus giving the appearance that the increased sports activity is causing the symptomatic foot pain. In reality, the combination of the two factors probably is the main reason for symptoms.

The young athlete may complain of insidious onset of pain or remember an acute onset of arch, ankle, or midfoot pain. The pain can be vague or localized over the coalition and be due to many factors, such as inflammation of the joints, nerve irritation or entrapment, muscle spasm, and microfractures (stress fractures) within the coalition. [0040] [0050] Any adolescent athlete with an inversion ankle injury that does not resolve after a full rehabilitation program should have tarsal coalition in the differential diagnosis. Other athletes who have not experienced an injury can present with pain located in the cuboid/navicular area that is aggravated by increased impact activities.

On physical examination, the patient classically presents with a valgus heel, pronation deformity, and abduction of the forefoot. The pronation deformity is rigid, meaning that the arch does not reform when nonweight bearing and is stiff to clinical examination. Furthermore, a weight-bearing calcaneal valgus is present and fails to go into varus on toe raising. This is distinguishable from the usually asymptomatic flexible flatfoot, which re-forms its arch with nonweight bearing. Subtalar motion is diminished on examination. Passive inversion may elicit pain as the shortened peroneal tendon is stretched. Examination findings sometimes are subtle in early stages and may require further radiologic studies.

Radiologic evaluation begins with plain films, which include anterior-posterior (AP), lateral, and oblique views of the foot and a tangential view of the calcaneus. The AP may demonstrate a talonavicular coalition. The oblique angle best demonstrates the calcaneonavicular coalition. The tangential view of the calcaneus (Harris axial view) best demonstrates a talocalcaneal coalition (middle facet). Bone scan typically is not used but may have a place as a screening procedure in cases that are difficult to determine. The gold standard remains computed tomography (CT). It is used to confirm diagnosis, determine surgical planning, follow up postoperatively, and evaluate degenerative changes. Magnetic resonance imaging (MRI) is becoming more useful, particularly in the young, growing population. MRI can detect soft-tissue bridging before ossification takes place.[6]

Treatment initially should be conservative for young athletes with tarsal coalitions. Both rehabilitation with aggressive Achilles stretching and custom orthotics can be used to improve the biomechanics of the foot and improve symptoms. Immobilization also can be used at times during a season to help the athlete calm the symptoms and possibly finish a season. Surgical intervention usually is the long-term treatment for athletes and can be done during the adolescent years or as dictated by nonresolving symptoms with sports. Athletes with no significant degenerative changes can expect to have an excellent or good surgical outcome.[7] Avoiding surgery in the young, symptomatic athlete may increase the risk of arthritis later in life.

Flexible Flat Feet

Flat feet, or pes planus/pes valgus, is a common problem in young athletes. Pes planus is a normal foot position up to 6 years of age.[8] Most young athletes with flat feet are asymptomatic and do not require any intervention. Wenger et al.[6] demonstrated that intervention with orthotics did not change the natural course of asymptomatic flat feet. The cause of this congenital problem is excess laxity of the joint capsule and ligaments, which allows the longitudinal arch to collapse during weight bearing. The arch re-forms when nonweight bearing and is accentuated with dorsiflexion of the first toe.

A full examination should be performed in a young athlete with flat feet, whether symptomatic or not. Among other questions in the history, the clinician should determine the length of symptoms, the effect of these symptoms on sports activity, and any systemic symptoms. Subtalar motion is one factor that can help differentiate pes planus from tarsal coalitions. The calcaneus should move passively between 20 and 60 degrees of inversion and eversion. When Achilles tendon flexibility is measured with the knee extended and the ankle/foot held in varus, ankle dorsiflexion less than 10 degrees below neutral indicates tight heel cords and may contribute to pes planus. If the athlete has no symptoms and the examination does not suggest a secondary cause, no further workup is necessary. These young athletes should be allowed to participate in all activities without restrictions. There is no evidence to date that preventative treatment with orthotics or other shoe inserts will prevent the development of symptomatic pes planus in the future. Children with unilateral, asymptomatic pes planus require more careful monitoring, as well as evaluation for neurologic and spinal causation.

If the athlete is seeking medical advice because of discomfort, then radiographs should be obtained to evaluate further for secondary causes. These may include accessory navicular, fractures, tumors, or coalitions.

Painful, flexible flat feet without secondary causes often respond to conservative measures. The young athlete must understand that this may be a chronic problem, but that extra work may help to alleviate the symptoms. Orthotics, aggressive heel cord stretching, and strengthening of the intrinsic muscle of the foot and posterior tibial muscle are the mainstay of treatment. Time also should be spent examining the footwear of young athletes. Worn-out shoes should be replaced with supportive footwear, especially a shoe with good medial longitudinal arch support.

 

Developmental problems in young athletes

Hallux Valgus

Bunions in children are less common than in adults. However, some studies have reported the prevalence to be as high as 35% in the adolescent population.[9] Bunions of the great toe are more common in girls than in boys. The developmental etiology of bunions is multifactorial, with an association of ligamentous laxity, hypermobile forefoot, pronation deformity, and metatarsus primus varus with hallux valgus. [0100] [0110] Shoes that place excessive stress on the first ray, such as narrow fitting and high heeled shoes, also are associated with increased irritation of bunions. Heredity is thought by some to play a role.[12] A young athlete with a congenital angle between the first and second metatarsals greater than 10 degrees is more prone to developing hallux valgus in the future.[11]

Parents and young athletes alike need to be aware of proper-fitting shoes. Children with rapidly growing feet may need several shoe changes during a single year. Prevention of this condition is the best treatment. If symptoms begin, the child may need to weigh the benefits of flat, wide shoes outside of sports versus the looks of more trendy narrow, heeled shoes. As with adults, weight-bearing x-rays and a physical examination usually are warranted when a young athlete complains of pain over the first ray. Because the natural history of this condition occurs over many years, initial workup may find the exostosis and thickened bursa at the medial head of the first toe to be less impressive than findings in an adult. Adolescent bunions also differ from late findings in adults in the lack of arthritic changes and spurs.[13]

Treatment is similar to that for the adult with regard to conservative measures. These include proper footwear, avoidance of aggravating activity, nonsteroidal anti-inflammatory drugs (NSAIDs), heel-cord stretching, orthotics, and education. Surgery should be postponed until after maturation of growth because recurrence of the deformity after osteotomies and capsulorrhaphies is common in young athletes.[14] Joint stiffness and discomfort at extremes of motion also is a problem for young athletes after surgery, and the athlete may never be able to return to his or her previous level.

Accessory Navicular

Most accessory bones about the foot and ankle are normal variants and often represent secondary centers of ossification. These variants often are asymptomatic and without clinical significance. However, some young athletes may develop symptoms that relate directly to the variant, such as the accessory navicular, or naviculare secundarium. The accessory navicular is one of several supernumerary ossicles first identified in 1605 by Bauhin (see Ref. 15). There are two types of accessory navicular. The first type is found within the posterior tibial tendon. The accessory navicular is present in about 10% of children; however, only 2% do not fuse by maturity. Anatomic studies have revealed that this accessory navicular ossicle is independent of the navicular bad break and can be thought of as a sesamoid bone.

The second type is an accessory ossification center medial to the navicular. During early development, this ossification center is surrounded by cartilage that is congruent with the cartilage of the navicular. The secondary ossification center typically fuses with the navicular near maturity, usually between 9 and 11 years. This type may be associated with symptomatic medial foot pain, especially in the adolescent athlete. This ossicle accounts for approximately 70% of all accessory naviculars.

The symptomatic accessory navicular should be thought of as an overuse injury. Increased stress on the overlying soft tissue causes inflammatory irritation and pain, especially if tenosynovitis has developed. It typically presents with pain and tenderness over the medial aspect of the foot, particularly the medial navicular. The athlete complains of pain with weight-bearing activity that is aggravated by tight-fitting shoes. The medial arch may be flattened secondary to posterior tibialis muscle fatigue or congenital foot pronation. Often the symptoms begin at the beginning of a new season. There is a higher predominance in girls than in boys, and the majority of patients first complain of symptoms during their adolescent years. Prominence is noted on the medial navicular on clinical examination.

Radiographically, the two types of accessory navicular should be distinguished because the first type does not commonly have symptoms. An oval or circular sesamoid on plain film is associated with the first type. Type II, or the commonly symptomatic ossicle, has a triangular and more irregular appearance.[16] Bone scan of a symptomatic navicular will demonstrate an area of increased uptake over the medial navicular ossicle.

Treatment initially should be aimed at conservative measures. These include a period of avoiding aggravating activities and using orthotics to eliminate pressure over the prominence. If pain is intolerable, immobilization in a short walking boot with or without an orthotic may be helpful to eliminate the muscle spasm and discomfort. Surgery is reserved for the persistent symptomatic ossicle that does not respond to several months of conservative treatment.

 

Acute injuries

Avulsion Fracture of Fifth Metatarsal

As in adults, young athletes often have inversion and supination injuries to their feet and ankles. In young athletes these inversion injuries often can lead to an avulsion fracture at the base of the fifth metatarsal. The middle school- or early high school-aged athlete will present with lateral foot pain and swelling. He or she typically notes a history of a significant inversion injury and the inability to continue participation. On examination the athlete will have palpable pain at the base of the fifth metatarsal that is more significant than pain at the lateral ligaments. Plain films of the foot, including AP, lateral, and oblique views, will easily detect the usually transversely oriented fracture. If concern exists regarding whether the plain films show a fracture or an unfused metatarsal physis, comparison films of the nonaffected foot may help to differentiate. Because this injury occurs with the injury mechanism commonly seen with lateral ankle sprains, the avulsion fracture may be missed if ankle films alone are obtained.

The most common fracture of the fifth metatarsal seen in young athletes is a transversely oriented avulsion fracture at the base of the fifth metatarsal and through the metaphysis. As noted previously, the injury commonly arises from an acute forceful inversion and supination injury of the foot/ankle. The mechanism is similar to twisting that produces lateral ligament injury of a sprained ankle. Recent cadaveric studies indicate that the lateral band of the plantar fascia is the structure responsible for the tuberosity avulsion, and not the peroneus brevis, as once thought.[17] It generally does not involve the articular surface but occasionally may extend into the cuboid-metatarsal articulation.[18] As mentioned, on roentgenographs this injury sometimes is confused with an unfused apophysis in a growing athlete.

If there is minimal displacement, conservative treatment is indicated using symptomatic immobilization. Our preference is to use a below-knee walking boot. However, a hard-soled shoe or a cast also is acceptable. The walking boot allows the athlete to almost immediately begin nonimpact conditioning with a stationary bike, stair-stepper machine, or elliptical trainer during the recovery time. After 3 to 4 weeks in the boot, the athlete can be weaned out of the boot into a steel-shank shoe insert. Limited impact sports activities can be started at 4 to 6 weeks while the steel-shank insert is worn, and progression is allowed using pain as a guide. Both plain films and symptoms are followed to assess healing. Radiographic healing may not be seen for several months and generally lags behind clinical symptoms.

A small percentage of avulsion fractures in young athletes will progress into nonunions. These athletes will have a history of a significant inversion injury that typically was treated with some type of immobilization. The athlete will present to the office over the next 6 to 24 months with the complaint of continued injuries and pain involving the base of the fifth metatarsal with sports activities. Plain films that include a comparison of the unaffected foot typically will be diagnostic. Surgical intervention then is typically required to allow the athlete to effectively return to sports.

Fifth Metatarsal Apophyseal Avulsion

The tendon of the peroneus brevis inserts into the apophysis. The apophysis can be distracted and avulsed with an acute inversion injury. Chronic repetitive stress results in Iselin's disease, as discussed later in the chapter. Patients present with pain over the base of the fifth metatarsal, and there may be widening of the apophysis on plain films.

The normal apophysis is parallel to the long axis of the metatarsal. The apophysis develops between the ages of 9 and 11 in females and 11 and 14 in males. It typically fuses several years later.[5]

If there is minimal displacement, then nonoperative treatment consists of boot immobilization for 3 to 6 weeks followed by progression to running and then to sports (2-3 months). If there is more than 2 to 3mm of displacement, surgery should be considered.

Os Vesalianum Sesamoid

This normal variant must be distinguished from an avulsion injury in the skeletally immature athlete.

Jones Fracture

As first described in 1902, the Jones fracture has a similar appearance to the avulsion fracture but is more distal in position.[19] It is located about 1.5 to 2.0cm from the proximal end, involving the metaphyseal-diaphyseal junction. This fracture also has a transverse orientation that is intra-articular. Although it commonly is described as occurring from an acute traumatic event, it can be secondary to chronic repetitive stress, such as from running.

This fracture is not commonly seen in the same age group as the fifth metatarsal avulsion fracture. It usually occurs in the older adolescent (15 to 20 years). Risk factors for this type of fracture include intense level of repetitive running and jumping, as seen in basketball and volleyball players. Another physical risk factor is the athlete who has hindfoot varus because of the increased stress of the lateral aspect of the foot. A high rate of delayed union or nonunion is due to the tenuous blood supply to this area.

Treatment for this fracture is somewhat controversial and is beyond the scope of this chapter. In general, we prefer to use intramedullary screw fixation if the growth plate is closed because it allows a quicker return to competitive sports as compared with bone grafting without screw fixation.

This fracture and its treatment options are discussed in Chapter 4 .

 

Pediatric ankle fractures

In young athletes with open growth plates, acute injuries to bone around the foot and ankle most commonly are fractures (bone or physeal). In adults, rotational forces and low-velocity sporting injuries generally cause ligamentous injuries, whereas in young athletes these same forces often result in physeal injuries. The growing bone in the young athlete differs from the adult in terms of the mechanical properties. Although the long bones in children are more compliant than in the adult, the physeal plate is vulnerable because it is the weakest link in the ligament-bone-tendon complex.

There are several pediatric fractures around the foot and ankle that are common yet can easily be overlooked. These fractures may have subtle clinical and radiographic findings. At the other extreme, a physician may treat an accessory ossification center noted on radiographs as an acute fracture. Recognition of the common fracture patterns and awareness of the pediatric bony variants are extremely helpful for the physician who cares for this population.

Approximately 5% of all pediatric fractures are around the ankle. They most commonly occur in the growing athlete involved in organized sports. The age range most commonly involved is 10 to 15 years.[0200] [0210] The annual incidence in this population is one physeal injury per thousand.[22] Radiographically, the distal tibial ossific nucleus appears between the second and third years, and physeal closure begins about age 15 in girls and 17 in boys. The distal fibula ossific nucleus is apparent during the second year and fuses with the shaft by 20 years.[23]

In most cases, conventional radiographs with comparison views allow adequate visualization of growth-plate injuries, and evaluation and treatment can be based solely on these findings. However, the role of additional imaging is being used more often with the knowledge that better visualization of soft tissue and bone is apparent with CT and MRI. Although the role of additional studies is still controversial, and there are no set guidelines to determine when additional studies should be used, several investigations have provided guidelines. CT or MRI may be beneficial in the patient with persistent unexplained symptoms and normal radiographs. MRI and spiral CT have been shown to detail fractures that were not visible on plain films. MRI or CT also may be helpful when surgery is contemplated and more detail of the injury, particularly nonossified areas, is required. [0240] [0250]

There are several systems of classifying ankle fractures in the literature. In the pediatric population, the Salter-Harris classification has been used since 1963 for planning treatment and predicting the long- term outcome of the injury.[25] Dias and Tachdjian (see Ref. 23) applied these principles and combined the mechanism of injury to assist with treatment. However, this system is difficult to discuss and beyond the scope of the chapter. In general, prognosis is determined by the grade of the fracture and the effectiveness of the reduction. As in adults, fractures that involve chondral surfaces have a better long-term prognosis the more anatomic the chondral surfaces are approximated.[26] Skeletal maturity at the time of injury also is important to consider because patients who are near skeletal maturity will have less risk of leg-length discrepancies in the long term.

Salter-Harris I distal fibula fractures, which are the most common ankle fracture in pediatric sports, typically occur from supination/inversion injuries.[27] This injury typically has the same injury mechanism as the adult lateral ankle sprain. Athletes will present with the history of an acute injury with pain and swelling over the lateral ankle. These athletes present similar to typical lateral ankle sprains, and the fractured growth plate can be missed easily. Careful palpation during the physical examination will elicit maximal tenderness at the distal fibula physis rather than the lateral ligaments. The distal fibula physis is palpated approximately 2 to 3cm proximal to the tip of the fibula. Plain films most often are normal but rarely show widening of the physeal plate with evidence of surrounding soft-tissue swelling.[28] Because plain films typically are normal, physical examination findings and an appropriate history are required to make the diagnosis. Once the clinical diagnosis is made, then the patient should be treated empirically with immobilization for 2 to 4 weeks. Immobilization can be accomplished with a walking boot, cast, or crutches and nonweight bearing. The walking boot allows the athlete to be more active in conditioning activities during the recovery phase. The athlete then can be weaned into a stirrup or lace-up–type brace, which will be used when returning to play at the 4- to 6-week mark. Although rare, Salter I fractures of the distal fibula can develop into nonunions. These athletes complain of continued lateral ankle pain with sports activity and often need surgical intervention to resume pain-free sports activity.

Salter-Harris I distal tibia fractures are less common than distal fibula fractures. Careful palpation of the distal tibia will help to differentiate this injury, as with the distal fibula injury. Immobilization with a boot or cast for 4 to 6 weeks generally will result in a good outcome. Patients should be followed with standing radiographs and comparison films for at least 1 year to ensure normal growth continues after the injury.

Salter-Harris II distal tibia fractures involve a fracture through the physis and metaphysis. Diagnosis often can be made with routine radiographs, but further imaging with a CT scan or MRI may be needed if the diagnosis is in question. This type also has a low risk of physeal arrest. Most displaced Salter-Harris II distal tibia fractures can be treated with closed reduction with sedation. If soft tissue blocks closed reduction attempts, then an open reduction is indicated. Immobilization with a long-leg cast for approximately 3 weeks is followed by below-knee immobilization for approximately 3 more weeks. As with Salter-Harris I fractures, patients should be followed with routine radiographs for at least 1 year to ensure normal growth.

Salter-Harris III fractures involve the fracture line proceeding from the articular surface dorsally to the physis and then laterally along the physis ( Fig. 23-1 ). These injuries have more potential long-term consequences. There often is intra-articular damage that cannot be seen on plain films. Closed reduction of the fracture can be attempted; however, if there is greater than 2mm of displacement, then an open reduction with smooth pinning is advised.[29] Long-term follow-up is important to recognize early signs of growth arrest and deformities.

 
 

Figure 23-1  Anterior-posterior radiograph of young athlete with a Salter Harris III fracture of the distal tibial physis.

 

 

Tillaux are a special form of Salter-Harris III fractures of the distal tibia. Tillaux fractures were described in 1848 and involve the distal anterolateral quadrant of the tibial physis.[30] The mechanism of injury is thought to be supination/external rotation with the foot planted. As a result of the pattern of fusion, central to medial and then lateral, the lateral corner is avulsed off with the attachment of the anterior inferior tibiofibular ligament.[22] These fractures occur in adolescents (12-14 years in girls and 14-18 years in boys) during the 18 months when the growth plate begins to fuse.[31] They account for approximately 5% of all pediatric ankle fractures.[25] This injury is complex, and additional studies usually are required to reveal the degree of displacement and extent of injury. Treatment of a nondisplaced fracture consists of closed reduction with internal rotation and axial distraction. If 2mm or more of displacement remains, then open reduction and anatomic reduction are indicated.[32] Poor anatomic reduction may result in growth deformities and long-term arthrosis.

In general, Salter-Harris IV fractures account for approximately 25% of all distal tibial fractures.[21] If a posterior metaphyseal fragment accompanies the type III Tillaux fracture, then it is classified as a Salter-Harris IV fracture, called a triplane fracture. Although there is a distinction between Salter-Harris III and IV distal tibia fractures by classification, similar treatment probably should be followed to avoid complications in the future. The fracture begins at the articular surface, extends through the epiphysis along the physis and into the posterior tibial metaphysis in three planes: sagittal, transverse, and then most proximally in the coronal plane. It can contain several fragments.[33] Two to four fragments are seen, depending on the maturity of the growth plate. Because of the complexity, CT or MRI is helpful in defining the fracture pattern, the amount of displacement, and the adequacy of postreduction alignment. Significant shorting after this injury is uncommon because the athlete usually is close to maturity.

Salter-Harris V fractures account for approximately 1% of distal tibial physeal injuries. The mechanism involves a compressive force across the physis. The plain films underestimate the damage to the physes. Unfortunately, the injury is discovered months to years after the event, when the patient has noticeable leg-length discrepancy or angular deformity. The treatment then is aimed at addressing these late complications. A high index of suspicion is required to detect these often-missed severe injuries. One clue to the diagnosis radiographically is the presence of multiple, small bone fragments at the level of the physis. Long-term complications are common despite early detection and appropriate management.

Complications of Physeal Ankle Fractures

Complications have been well documented after treatment of ankle fractures involving the growth plate. Obviously, the initial injury and the damage that occurred during the event are unpreventable. However, the treatment following the inciting event can have a dramatic impact on long-term results. Further damage can be minimized by limiting the attempts at reduction. Early recognition and immobilization have an impact on healing and long-term outcome. The importance of the physical examination is that it may prevent ongoing injury from being missed. Compartment syndrome of the anterior compartment has been described in the literature, and sign and symptoms should not be overlooked on the initial examination.[34]

Although growing athletes have an incredible ability to heal quickly and often without complications, fractures involving the epiphyseal plate can result in permanent disability and deformity. The degree of angular deformity and leg-length discrepancy resulting from premature closure of the plate depends on the age and bone maturity of the athlete when the injury occurs as well as the amount of displacement of the physis and fracture. The distal tibial physis contributes approximately 4mm of growth per year.[22] An injury to this area at the end of growth most likely will not have a dramatic affect on leg length. Bony fusion generally is completed by 14 years in females and 16 years in males. Age and family history will help guide the physician in determining the predicted remaining growth of the tibia. Less than 1cm of discrepancy is considered acceptable and does not have reproducible long-term deleterious effects on the foot and ankle. Follow-up radiographs should be obtained to evaluate for growth disturbance.

Inaccurate physeal reduction leading to an asymmetrical growth arrest is a potential problem in the young athlete. If accurate reduction of the articular surface cannot be maintained with closed means, then open reduction must be undertaken. In a study by Kling et al.,[20] patients with Salter-Harris III and IV ankle fractures had less growth arrest when open reduction/internal fixation was the treatment of choice versus closed reduction. When considerable angle deformity exists after initial treatment of an unrecognized fracture, then an osteotomy can be the best solution to correct the alignment and prevent further long-term stress and complications on the joint.

As with adult fractures, osteoarthritis may result from the inciting injury, particularly when the chondral surface is involved. A study by Caterini et al.[35] looked at the long-term follow-up after physeal injuries of the ankle. They concluded that Salter-Harris injuries that involved the articular surface had an increased rate of osteoarthritis as compared with those without involvement of the chondral surface. Several other studies have concluded that anatomic reduction decreases the rate of osteoarthritis.

All injuries involving any joint may result in stiffness, muscle atrophy, and, rarely, complex regional pain syndrome. Careful follow-up and physical therapy addressing early range of motion and strengthening the supporting muscles may have a role in preventing these long-term complications.

 

Osteochondroses

The osteochondroses comprise a group of clinical syndromes that occur during years of growth and affect the primary and secondary growth centers. Typically young athletes present with symptoms of pain during sports activities. Although there have been a number of studies looking at the cause of these growth-plate problems, the etiology is still unknown. Physical activity appears to play an important role, but it is not clear whether this is the major contributing factor.[36] Osteochondroses of the foot and ankle typically do not cause long-term problems and can be treated conservatively. Understanding the presentation and treatment of these overuse problems can help get young athletes back to sports activity more quickly and safely.

Kohler's Disease

Kohler's disease is a foot disorder in children characterized by sclerosis and collapse of the developing tarsal navicular. The problem is seen most typically in active children between 4 and 7 years of age and seems to affect boys more commonly than girls.[37] The navicular typically is fully ossified by adolescence, and thus Kohler's disease presents at this younger age.[38]

Patients often present with a noticeable limp and complain of medial foot pain that is associated directly with physical activity or immediately following activity. The pain can range from vague discomfort to disabling pain with ambulation. The physical examination may reveal an area of erythema and swelling over the navicular. On examination the area overlying the navicular may appear erythematous and swollen. Palpation over the medial aspect of the navicular produces pain.

Routine radiographs are an important first step in diagnosing Kohler's disease. Plain films also will help to rule out other possible diagnoses such as tumor, infection, and stress fractures. Most cases are unilateral, so comparison films of the uninvolved foot are helpful. The diagnosis is confirmed by the typical appearance of a narrowed or flattened navicular and/or increased density ( Fig. 23-2 ).[39]Occasionally there is a fragmented and patchy appearance. The joint spaces of the surrounding bones are well preserved to help rule out other systemic illnesses. A bone scan will be positive for increased uptake in the navicular with Kohler's disease. CT scan also can be used to confirm the diagnosis but may not be needed if the clinical examination and radiographics are diagnostic.

 
 

Figure 23-2  Lateral radiograph of the foot demonstrating Kohler's disease. Note the sclerosis of the navicular.

 

 

Treatment consists of a conservative approach at first. NSAIDs have been shown to help alleviate the pain initially. Several studies have looked at different treatment options from orthotics to casting for several months. It has been found that immobilization has affected the duration of symptoms. Immobilization in a walking cast or boot decreases time of symptoms by an average of 7 months. Long-term studies have not shown a difference with respect to the type of treatment used.

The prognosis is excellent, with few athletes having long-term disability. Young patients can be allowed to return to play when the symptoms subside. Immobilization should be for 6 to 12 weeks. An orthotic often is used to help alleviate stress over the involved joint. When poor results do occur with conservative management, arthrodesis of the talonavicular joint sometimes is required.

Freiberg's Disease

Osteochondrosis of the metatarsal head, or Freiberg's disease, involves an evolutionary process of deterioration and collapse of the articular surface and underlying subchondral bone. It occurs more commonly in adolescents when the epiphysis is still present, and 75% of the cases are female.[40] The second metatarsal is the most common site (68%) followed by the third and forth metatarsal heads being affected.[41] The second metatarsal head is involved more commonly when it is longer than the first. It has been proposed that this results in increased pressure over the head and possibly disruption of the vascular supply with repeated microtrauma (i.e., running or dancing en pointe).

The athlete typically presents with forefoot pain that is worsened with impact activities. Activities that cause extremes of motion at the metatarsal heads during weight-bearing activities such as sprinting and repetitive jumping particularly seem to exasperate symptoms. Athletes usually will complain that the pain symptoms are continuing to worsen by the time they seek medical help. The physical examination may show some mild swelling over the metatarsal head. Palpation of the midfoot and forefoot typically isolates pain to the affected metatarsal head and its metatarsophalangeal (MTP) joint. Motion at the affected MTP joint will be decreased and painful.

Radiographs of the foot should be obtained when a young athlete presents with these symptoms and physical examination findings to evaluate for Freiberg's disease and to rule out other causes, such as infection or stress fractures. Initial plain film findings, such as widening of the affected MTP joint space, may be subtle. Osteosclerosis of the metatarsal head may be seen within several weeks on plain films ( Fig. 23-3 ). As the disease progresses, there is increased resorption of necrotic bone with resulting fragmentation and collapse of the metatarsal head.[42] Bone scan may be helpful when the clinical examination and history are suspicious but radiographs are negative. The bone scan will show increased uptake in the proximal metatarsal head and decreased uptake over the necrotic area.

 
 

Figure 23-3  Anterior-posterior radiograph of the foot demonstrating sclerosis of the second metatarsal head and early evidence for collapse consistent with Freiberg's infraction.

 

 

Treatment consists of taking anti-inflammatories and decreasing the load to the area for a period of time. Initial immobilization in a walking boot will help to calm symptoms. The athlete then may be transitioned into an orthotic and started back to nonimpact activities initially. It is not always possible to stabilize the joint and prevent pain and progressive deformity. In severe cases with persistent pain, surgery may be required to alleviate symptoms and remove impingement. In later stages, it is believed that the discomfort is associated with loose bodies. There are several procedures, depending on the extent of the disease and whether loose bodies are present. All have reported very good results.

Osteochondral Talar Dome Lesions

Osteochondral lesions of the talar dome, also called osteochondritis dissecans, may be a cause of ankle pain in children, as well as in young adult athletes. Lesions of the talar dome are well documented in the adult population (see Chapter 14 ); however, with advances of MRI and the growing awareness of this condition in young athletes, it is more common among adolescents than once thought. An article published by Canale and Belding[43] in 1980 found the majority of the subjects to have symptoms dating back to adolescence. This disorder should be suspected in an adolescent with a history of an ankle sprain that does not improve as expected.

The etiology of the lesion is controversial. Canale and Belding[43] found the lesions to be caused by trauma in 31 reported lateral talar dome lesions. Medial lesions were not as conclusive, with only 64% of the cases related to a traumatic event. Like many other types of osteochondral lesions, vascular insufficiency may play a role in the development and progression of the lesion. Central lesions are rare. The male-to-female ratio ranges from 3:1 to 2:1.[44]

Athletes usually present with a history of an inversion injury. Acutely, there often is a large effusion and diffuse pain. Range of motion often is limited. Palpation over the anterior joint line is tender. Absence of tenderness over the lateral ligamentous complex should further raise suspicion of a talar dome lesion. Although locking and a catching sensation are classically described for loose body formation, this is an uncommon presentation.

Berndt and Hardy in 1959 (see Ref. 43) published a classification system based on standard radiographs. Grade I is a depressed chondral fracture with the overlying articular cartilage intact. Grade II is a fragment that is incompletely separated. Grade IIa has formation of a subchondral cyst seen on MRI. Grade III is a detached fragment that may have some articular cartilage still attached. The fragment is not displaced. Grade IV is a displaced fragment.

Routine three-view radiographs of the ankle should be obtained before MRI, because grade IV lesions may not be readily apparent on MRI. Stage I lesions do not show up on plain film. If suspicious for this type of lesion, a mortise view with the foot in full plantarflexion will help the clinician to view posterior medial lesions, and dorsiflexing the ankle with AP radiographs will help in visualizing the lateral dome lesions. MRI will show a well-demarcated area of abnormal signal. The bone scan will show a focal increase of tracer uptake. Grade II to IV lesions may be visible on plain films.

Treatment depends on the grade of the lesion. There have been higher failure rates in nonoperative treatment for adults as compared with young athletes.[44] It is acceptable to immobilize a low-grade lesion to see whether symptoms resolve. If conservative measures fail, then surgical treatment is recommended. This may be an evolutionary process with grade I lesions progressing to grade IV lesions. Grade IIa and above may require immediate excision to avoid long-term arthosis.[45]

 

Nonarticular osteochondrosis

Sever's Disease

The differential diagnosis for heel pain in young athletes is similar to that for adults, with few additional considerations. Overuse injuries in children were relatively rare until the advent of organized sport. With rapid bone growth and increased activity levels during youth, increase stresses are placed on developing apophyseal bone. Sever's disease, or calcaneal apophysitis, was first described in 1912 as a cause of posterior heal pain and thought to occur in physically active, overweight children.[46] It now is known to occur in nonobese children as well.

Sever's disease is a traction apophysitis that causes pain along the secondary calcaneal ossification center. The insertion of the Achilles tendon over the longitudinally oriented surface subjects the epiphysis to strong traction forces. The apophysis typically is irregular looking with multiple fragments and increase density; however, it is radiographically similar to the opposite asymptomatic heel. For this reason, x-rays are not diagnostic but can be helpful in ruling out stress fractures or bone tumors.[47] The epiphysis begins to fuse between 12 and 15 years of age. This area therefore is most vulnerable before this age, and the incidence of Sever's disease is highest between 6 and 8 years of age.[48]

There appear to be several predisposing factors that contribute to Sever's disease. Biomechanical abnormalities, overuse during activity, and increased stresses all play a role.[49] Hallux valgus, pes planus, and pes cavus all may have an association with Sever's disease. Forefoot pronation is most commonly associated. These structural abnormalities alter the biomechanics and forces applied to the heel, decreasing shock absorption and exposing the heel to abnormal stresses.

Most sports such as running require repetitive heel-cord loading and expose this area to microtrauma. Athletes may ignore the discomfort initially and continue with long, intense workouts before seeking medical advice. One should be aware of the sports most commonly associated with this syndrome. Basketball, soccer, track, and gymnastics have been found to have the highest association.[50] Sports played on hard surfaces also may contribute to the increased stress and microtrauma.

The final predisposing factor probably is the most significant in terms of treatment. Abnormal stresses may be secondary to inflexibility. The heel-cord complex, as a result, has diminished dorsiflexion and may contribute to abnormal stresses on the apophysis during activity.[51]

The child may present with heel pain, particularly with running. Often the young athlete is starting a new season. The pain is absent in the morning, begins with exercise, and lessens during nonweight-bearing activity. The pain may begin insidiously, or the athlete may remember an inciting history of direct trauma to the heel.[52] The pain may become debilitating and prevent the athlete from participating in his or her sport.

On examination, one should look for the previously mentioned biomechanical abnormalities. Dorsiflexion of the ankle is important to document. If the dorsiflexion is less than -10 degrees, then a severe Achilles contracture is present. The patient may limp or complain of reproducible pain when he or she rises up on the toes. This is known as a positive Sever's sign. Pain to palpation over the posterior mediolateral heel and a positive squeeze test are suggestive of Sever's disease.

Although radiographs may not help to distinguish Sever's disease from a normal-appearing asymptomatic heel, they may rule out other mimicking conditions such as a fracture, coalition, or tumor.

Treatment varies depending on the severity of the pain and the reliability of the patient. There have been no studies to date that have shown long-term sequelae after treatment for Sever's disease. Initial management is conservative, and aggravating activities should be avoided until symptoms improve. Icing, heel lifts, anti-inflammatories, and physical therapy also are helpful. In our practice, a home program of aggressive heel-cord stretching usually is curative. If the pain returns after treatment, one should consider orthotics if biomechanical abnormalities exist. If there is persistent heel-cord inflexibility, then nighttime splints may be helpful. Rarely is pain debilitating enough to require a walking boot. Often the pain subsides in several weeks to 2 months, and the athlete can return to sport with a functional progression program.

Iselin's Disease

Iselin's disease, or traction apophysitis at the base of the fifth metatarsal, was first described in 1912 as occurring in adolescents.[53] The confusing pathology of this metatarsal can make fractures or os vesalianum difficult to distinguish from Iselin's disease on roentgenographs. The apophysis develops between the ages of 9 and 11 years in girls and 11 and 14 years in boys. It begins to fuse 2 to 3 years later. The apophyseal growth cartilage is the weakest site for ligament and tendon attachment in growing children.[26] With intense training, this area can develop microavulsion fractures or traction apophysitis.

The proximal fifth metatarsal is the site of three ligament attachments: the plantar fascia and the fourth and fifth metatarsal ligaments. The peroneus brevis and peroneus tertius also insert into this area. During growth, the secondary growth center of ossification is located on the lateral plantar aspect of the tuberosity. This bone is within the cartilaginous flare onto which the peroneus brevis tendon inserts.[54] With continued longitudinal stress, this bone may become irritated and painful.

Young athletes, more often male, present with tenderness over the proximal fifth metatarsal. Similar to Sever's disease, Iselin's disease often occurs at the beginning of a season. The onset may be insidious or acute with a history of an inversion injury. The pain usually is worse during activity. Any activity that fires the peroneal muscle will elicit pain. Maneuvers such as running, especially lateral and cutting movement, will produce discomfort.

On examination the area will be tender to touch. Resisted eversion or passive, extreme plantarflexion with inversion may elicit pain. Occasionally the area may appear erythematous and swollen. Weakness on resisted eversion may be evident because of protective pain.

Radiographically, AP and lateral views may not show the secondary ossification center. A third medial oblique view should be taken when examination findings are suspicious. This may show a small piece of bone oblique to the fifth metatarsal shaft on the lateral plantar aspect of the tuberosity. Bone scan will show increased uptake over the proximal fifth metatarsal. Plain films will be helpful in ruling out similar conditions such as Jones fractures. Therefore history, physical examination, and radiographic finding of the secondary ossification center will aid in making the diagnosis.

The treatment for Iselin's disease depends on the degree of the athlete's pain and his or her willingness to comply with the treatment program. Initially, conservative management is all that may be required.[55] Avoidance of the causative stresses, ice, NSAIDs, and stretches may be helpful. In more stubborn cases, in which pain does not improve and returns, immobilization in a walking boot often relieves the symptoms. There have been several reported cases of Iselin's disease developing into a nonunion. If this occurs, surgical intervention is warranted. This entails either fixation of the bony fragment or excision of the proximal bony fragment.

 

Conclusion

Pediatric foot and ankle problems are common. They are similar to adult conditions but with the complicating factor of injuries to the growing bone and physis. It is important to understand and be familiar with the developing skeleton to distinguish among normal growing bone, osteochondroses, accessory bones, ligament injuries, and bone fractures. The additional confounding factor of residual growth with physeal injuries presents even more potential for complications and a greater need to be accurate with diagnosis and treatment. One should obtain comparison radiographs when subtle finding are confusing. Routine use of comparison views will result in unnecessary exposure and expense.

 

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