Iliac crest apophysitis is an overuse injury commonly seen in runners and hockey, soccer, and football players. The main symptom is pain over the affected iliac crest that is worsened with running. Plain radiographs are normal. Treatment is conservative and includes anti-inflammatory medication.
Developmental (Congenital) Hip Dislocation
Developmental hip dislocation, previously known as congenital hip dislocation, is an intra-articular displacement of the femoral head from its normal position within the acetabulum. This leads to an interruption in the normal development of the joint occurring before or shortly after birth. At birth, the acetabular fossa is shallow with the superior portion of the acetabulum poorly developed, offering little resistance to the upward movement of the head by muscle pull or weight bearing. This leads to a condition called congenital subluxation of the femoral head, in which the femoral head is displaced laterally and proximally, and articulates with the outer portion of the acetabulum. In complete dislocation of the hip, the femoral head is located completely outside the acetabulum and rests against the lateral wall of the ilium. Later, a false acetabulum forms with a capsule interposed between the femoral head and the ilium.
In the normal infant, one sees folds in the groin, below the buttocks, and several along the thigh, which are symmetrical. In subluxation or dislocation, these folds will be asymmetrical. When the examiner places the infant on the table, the pelvis and the limb on the affected side will be pulled proximally by muscle action. This proximal displacement causes apparent shortening of the limb.
The Ortolani click test is performed as a routine part of the examination on infants before 1 year of age. In the normal infant, when the hip is flexed 90 degrees and the thigh is abducted, the lateral aspect of both thighs will nearly touch the table. In subluxation or dislocation, abduction is restricted and the involved hip is unable to be abducted as far as the opposite one, producing an audible or palpable click as the femoral head slips over the acetabular rim (Fig. 6–32).
The Ortolani click test. In subluxation or dislocation, abduction is restricted and the involved hip is unable to be abducted as far as the opposite one, producing an audible or palpable click as the femoral head slips over the acetabular rim.
The Barlow provocative test is performed with the newborn positioned supine and the hips flexed to 90 degrees. The leg is then gently adducted while posteriorly directed pressure is placed on the knee. A palpable clunk or sensation of movement is felt as the femoral head exits the acetabulum posteriorly. The Ortolani and Barlow maneuvers are performed one hip at a time.
Repeat examination of the infant is mandatory until the child starts walking because the lack of symptoms and subtle physical findings make early diagnosis difficult. Patients with late-presenting developmental dysplasia of the hip (DDH) will typically present with a painless limp. There is usually a history of a delay in walking with the age of onset being between 14 and 15 months, instead of 12 months. The affected lower leg may be shortened. If the DDH is bilateral, the toddler may walk with a waddle. A radiograph of the pelvis after 4 months of age will help to confirm the diagnosis (Fig. 6–33). Ultrasound may be effective for early diagnosis of this disorder in infants of less than 4 to 6 months.22 However, the use of screening ultrasounds is not recommended. Close physical examination and referral to orthopedics for suspected cases is appropriate.23
Developmental hip dislocation of the right hip. A. AP and B. Frog leg lateral.
Legg–Calvé–Perthes Disease (Coxa Plana)
Legg–Calvé–Perthes disease (LCPD) is an idiopathic form of avascular necrosis of the femoral head occurring in children (Fig. 6–34). This condition, which affects boys three to five times more often than girls, occurs most often in children between 4 and 9 years.
Legg–Calvé–Perthes disease is present bilaterally.
The definitive cause of the vascular disturbance resulting in LCPD is unknown. The condition results in necrosis of the head and all or part of the epiphysis. An almost constant early sign is a limp, which is caused by limited abduction of the hip and limited internal rotation in both flexion and extension. The patient complains of a vague ache in the groin that radiates to the medial thigh and inner aspect of the knee. This is aggravated by activity and relieved by rest. The patient may also complain of stiffness in a joint, and tenderness is noted over the anterior aspect of the joint. Muscle spasm is another common complaint in the early stages of the disease.
The early signs on x-ray are of joint space widening and prominence of the soft tissues over the capsule with a minimal joint effusion. The femoral head may be shifted slightly laterally in the acetabulum. A few weeks later, the femoral head will appear denser than the rest of the bone. Later, a fragmented appearance on the radiograph is evidence of necrosis; ingrowth of new vessels initiates the process of reabsorption. This results in a decreased density of the proximal end of the metaphysis because of increased vascularity. Osteosclerosis with broadening and shortening of the femoral neck and an increased density of the head is also seen. Eventually, osteoarthritis develops.
Initial therapy includes minimal weight bearing and protection of the joint, which is accomplished by maintaining the femur abducted and internally rotated. This will keep the femoral head well inside the rounded portion of the acetabulum. Abduction and rotation of the femur is accomplished either by the use of orthotic devices (bracing) or surgery (osteotomy).
The Scottish Rite brace achieves containment by abduction, while allowing free knee motion. This brace allows the hip to flex to 90 degrees, but it cannot control the rotation of the hip. In older patients with more extensive femoral head involvement, surgical repair results in improved outcome when compared with nonsurgical management.24,25
Slipped Capital Femoral Epiphysis
Slipped capital femoral epiphysis (SCFE) occurs in children between the ages of 10 and 16 years with a male predominance. Patients are typically overweight with over 80% of patients having a body mass index above the 95th percentile.26 In approximately one-fourth of the cases both hips are affected. There is an increased frequency of this disorder in patients with endocrine disorders, including hypothyroidism, growth hormone deficiency, and hypogonadism. The capital femoral epiphysis is weakened and displaced downward and backward, resulting in a very disabling external rotation deformity of the lower extremity that later goes on to form degenerative arthritis of the hip.
In many of these patients, there is a history of rapid skeletal growth before the displacement. The patient may present to the ED with a history of minor trauma or strain, but persistent symptoms. This condition is found in children who are typically obese with underdeveloped skeletal characteristics, and is less commonly seen in tall, thin children. Weight bearing and muscle contraction cause the displacement to worsen. Young athletes between the ages of 8 and 12 years with knee discomfort and no effusion should be investigated for SCFE.
On examination, the hip is externally rotated and there is pain and diminished range of motion to internal rotation, abduction, and flexion. When this occurs, the patient’s diagnosis is clear and the approach is fairly straightforward. Often, clinical findings are subtle and may be missed.27
Three clinical stages exist. In the preslipping stage, there is slight discomfort about the groin, which usually occurs after activity and subsides with rest. The patient may complain of stiffness and an occasional limp. Discomfort may radiate along the anterior and medial aspect of the thigh to the inner aspect of the knee. The symptoms are usually vague, and no objective findings are noted on physical examination. The second stage is the chronic slipping stage, where the epiphysis is separated and gradually shifts backward, as is usually noted on x-rays taken during that time. In this stage, a patient has tenderness around the hip joint and limitation of motion (particularly abduction and internal rotation). The limb develops an adduction and external rotation deformity. As the hip is flexed and externally rotated, the slipping is accentuated, and the gluteus medius becomes inadequate. The patient develops a positive Trendelenburg test. When the condition is bilateral, the patient has a waddling gait. This is followed by a stage of fixed deformity in which pain and muscle spasm disappear. The limp and external rotation and adduction deformity persist, as does the limitation of internal rotation and abduction.
AP views of both hips should be taken (Fig. 6–35A). In addition, a lateral view taken in a frog position, with the hip flexed 90 degrees and abducted 45 degrees, will demonstrate the displaced capital femoral epiphysis (Fig. 6–35B). In the preslipping stage, a globular swelling is seen in the joint capsule. This is accompanied by widening of the epiphysis and decalcification of the metaphysis at the epiphyseal border caused by inferior and posterior slipping of the head. Other clues to the diagnosis of slipped epiphysis include a wide irregular or mottled epiphyseal plate, metaphyseal rarefaction, and periosteal new bone formation. Kline’s line, a line drawn through the superior border of the proximal femoral metaphysis, should intersect part of the proximal femoral epiphysis. If this does not occur, SCFE should be suspected (Fig. 6–36). Comparison of this line’s intersection to the other hip is helpful in subtle cases. In addition to this, loss of Shenton’s line is a commonly seen radiographic finding (Fig. 6–37). When the relationship of the femoral head to the acetabulum is uncertain on the plain radiographs, a CT scan is often able to diagnose the problem readily.
Slipped capital femoral epiphysis A. AP view demonstrates obvious slip of the right hip. B. A frog leg lateral view in a different patient demonstrating a more subtle slip of the right hip. On this view, a line drawn through the femoral neck should bisect the head on a normal radiograph. This is not the case in this patient.
Kline’s line. A normal Kline’s line should intersect the epiphysis of the femoral head. A. Normal hip. B. SCFE.
Shenton’s line. Interruption of this line suggests an abnormal position of the femoral head.
These cases must be diagnosed early, and once suspected, referred immediately to the orthopedic surgeon for definitive treatment. This involves reduction of the slipped epiphysis and no weight bearing. The priorities in treating an unstable (acute) slip are to avoid avascular necrosis, avoid chondrolysis, and prevent further slip as well as correct the deformity.
Axiom: Remember that any child who presents with knee pain who has a normal knee examination must have the hip examined for possible etiology.
Transient synovitis is the most common cause of acute hip pain in children between 3 and 10 years of age. Typically, these children present with hip pain of 1 to 3 days duration, accompanied by a limp or a refusal to bear weight. The extremity is held in flexion, adduction, and internal rotation, while the child resists all attempts at passive motion resulting from muscle spasm. The temperature is usually normal to slightly elevated, and is rarely high. This condition has an uncertain etiology and is diagnosed through a process of exclusion. Patients often report a preceding viral or bacterial infection. The disorder is usually unilateral, although it can be bilateral. The treatment for transient synovitis is rest and anti-inflammatory medication with close follow-up.28
Septic arthritis must first be ruled out, because femoral head destruction and degenerative arthritis will result if septic arthritis is not treated promptly. These patients, unlike patients with transient synovitis, are toxic in appearance and generally have high fevers. The patient resists any attempts at range of motion. When the diagnosis is unclear (temperature <102°F, limited range of motion, and negative ultrasound), a brief period of observation after a dose of ibuprofen may help differentiate the two entities, as the child with transient synovitis will improve.
However, if any doubt exists as to the etiology of the pain, blood cultures, antibiotics, aspiration of the hip joint, and culture of the synovial fluid are mandatory.
Septic Arthritis and Osteomyelitis
Septic arthritis and osteomyelitis are not uncommon in children. The pathologic origin is hematogenous seeding, local invasion from contiguous infection, or direct inoculation of the bone, either surgically or after trauma.
The presentation of septic arthritis is usually that of a fever, which may be low grade, and what is called pseudoparalysis, which essentially is a refusal of the child to use that limb. Gentle passive motion, however, is usually allowed. Presenting symptoms in neonates may be as vague as increased irritability, fever, or poor feeding. Children with osteomyelitis have tenderness to palpation particularly over the metaphysis, which is commonly affected. When the hip and shoulder are involved in osteomyelitis, the pus can track under the periosteum of the metaphysis into the adjacent joint and thus the patient may have findings of both osteomyelitis and septic arthritis. The diagnosis of osteomyelitis can be made by the presence of any two of the following diagnostic criteria:
Purulence of the bone
A positive bone or blood culture
Localized erythema, edema, or both
A positive imaging study, either on radiography, scintigraphy, or MRI
Cultures taken from bone result in a culture yield of 80%. Blood cultures should be drawn on all patients suspected of having osteomyelitis, as they are positive in up to 50% of patients. The most common organisms involved in newborns include staphylococci, Haemophilus influenzae, and gram-negative bacilli. In infants and children, S. aureus is the most common major organism. However, Goergens et al.29 found methicillin resistant S aureus to be an emerging organism contributing to 6% of septic arthritis cases. H. influenza disease is no longer a threat due to universal vaccination except in neonates and unimmunized children. Neisseria gonorrhoeae should be suspected in sexually active teenagers. Patients with sickle cell disease are also at risk for Salmonella-related osteomyelitis.
Jung et al. in a univariate analysis showed significant differences in body temperature, serum WBC count, erythrocyte sedimentation rate (ESR), and CRP levels between patients with septic arthritis versus transient synovitis. Plain radiographs showed a displacement or blurring of periarticular fat pads in patients with acute septic arthritis, and multivariate regression analysis revealed that a fever, ESR greater than 20 mm/h, CRP greater than 1 mg/dL, WBC greater than 11,000/mL, and an increased hip joint space of greater than 2 mm were independent predictors of acute septic arthritis.30 In a prospective study of patients with suspicious physical examination findings, Caird et al.31 found that fever (an oral temperature >38.5°C) was the best predictor of septic arthritis followed by an elevated CRP level, an elevated ESR, refusal to bear weight, and an elevated serum WBC count. In their study group, a CRP level greater than 2 mg/dL (>20 mg/L) was a strong independent risk factor for having septic arthritis of the hip.
The femur and tibia are by far the most common bones affected. Plain films are generally normal and it takes 7 to 10 days for radiographic changes to appear in either osteomyelitis or septic arthritis.32 Soft tissue, however, may show changes earlier. The younger the child, the more likely one is to see widening of the joint space. Abnormal subluxation of the hip with widening of the joint space is the most common x-ray finding. Because plain x-rays are usually not helpful early in the course of this disease, a low threshold should be used for skeletal scintigraphy. Scintigraphically guided aspiration of the hip evacuates pus, decreases damage to periarticular surfaces, differentiates joint sepsis from other effusions, and helps direct antibiotic therapy. CT scans are not useful in establishing a diagnosis of acute musculoskeletal sepsis.33
In treating children with osteomyelitis and septic arthritis, β-lactamase-resistant antibiotics should be included particularly due to the prevalence of MRSA .In patients who are allergic to penicillin, clindamycin 24 mg/kg in divided doses over 24 hours, or vancomycin is indicated.34
Osgood–Schlatter disease represents a disturbance in the development of the tibial tuberosity caused by repeated and rapid application of tensile forces by the quadriceps muscles at its tendinous insertion on the tuberosity.35 , 36 The most widely accepted cause of Osgood–Schlatter disease is chronic repetitive trauma to the anterior portion of the maturing proximal tibial growth plate.
This disease is typically seen in girls between 8 and 13 years of age and in boys between 10 and 15 years. The disorder has been associated with inflexibility of the quadriceps muscle. The condition is usually unilateral, but it may be bilateral in 35% to 56% of boys and approximately 18% of girls.37 In addition, boys are affected more often than girls.
On examination, there is typically pain, swelling, and tenderness localized over the tibial tubercle (Video 6–4). Joint effusion should not be present. Quadriceps used against resistance aggravates the pain, particularly during climbing steps, squatting, or kneeling. These symptoms are secondary to incomplete separation of the cartilaginous link between the patellar tendon and the tibia. The separation interrupts the blood supply, resulting in aseptic necrosis, fragmentation, and eventually new bone formation (Fig. 6–38). Fusion of the tubercle to the tibia occurs by 18 years of age, thus eliminating any further symptoms. MRI and ultrasound of the knee have been shown to be superior to plain radiographs in diagnosing Osgood–Schlatter disease.38 However, neither of these studies is immediately necessary in the ED.
The treatment includes a reduction of activity (i.e., sprinting, jumping, and kicking) for 2 to 4 months, ice after exercise and a short course of nonsteroidal anti-inflammatory medications.39 Resolution of symptoms may take up to 12 to 18 months.40 Stretching exercises for the quadriceps and hamstrings are also helpful. Complete restriction of all athletic activities is generally not necessary. Corticosteroid injections are not recommended due to the risk of subcutaneous atrophy and degenerative changes. Some patients develop chronic pain, which is associated with a discrete ossicle in the patellar tendon. Surgical treatment can provide relief in these patients.41 Immobilization is not generally recommended except in severe or persistent cases.
Apophysitis of the inferior pole of the patella is referred to as Sinding–Larsen–Johansson disease. This condition is also called inferior pole patellar chondropathy and is nine times more prevalent in boys between the ages 10 and 14 years than it is in girls. Patients present with lower-pole patellar pain exacerbated by running or kneeling. On examination, pain is noted with extension against resistance along with localized tenderness on the inferior pole of the patella. With protracted symptoms, there is an elongation of the involved pole, which may develop a stress fracture and eventually an avulsion fracture if not diagnosed. Radiographs are usually normal, although blurring of the poles may be seen in chronic cases. The treatment is similar to Osgood–Schlatter disease. Nonsteroidal agents and rest are recommended. This condition is self-limited and usually resolves completely within 12 to 18 months. In rare cases, a 2- to 3-week trial of crutches is necessary.
Patellofemoral Stress Syndrome
Patellofemoral stress syndrome is the most common complaint in young female athletes. The common presentation is of aching knees, with pain increased by jumping or climbing. Physical findings usually include pain on compression of the patellar region; joint effusion and swelling are rare. Plain films are normal. Treatment includes relative rest and physical therapy.
Ligamentous injuries involving the knee are uncommon in children because the bone is weaker than the ligaments. In the knee, an adult will experience a talofibular ligament rupture, whereas a child more frequently suffers a Salter I orII fracture of the proximal tibia or distal femur. Following a rotational injury or varus stress to the knee in a child, an avulsion of the tibial spine occurs more frequently than an anterior cruciate ligament rupture. By the same token, it is more common in the adult to have a rupture of the patellar tendon or quadriceps tendon from an extension-block injury to the quadriceps apparatus, whereas a child is more likely to suffer an avulsion of the tibial tubercle. Subtle and occult fractures are common in children. For this reason, a child with an effusion following a knee injury and negative plain radiographs should be immobilized and referred.
In dealing with a patellar injury or dislocation, always remember to examine the undersurface of the patella, as osteochondral chip fractures are more common in children than in adults.
A toddler’s fracture is a nondisplaced spiral or oblique fracture of the lower third of the tibial shaft. This fracture occurs in patients between the ages of 9 months and 3 years. This injury results from torsion of the lower leg (Fig. 6–39). A fibula fracture is not present. Often, the parents do not recall any trauma and the only complaint is difficulty walking or resistance to weight bearing. Physical examination often fails to reveal swelling, but may show increased warmth and pain with palpation of the lower third of the tibia.
Toddler’s fracture of the tibia. Note the subtle oblique fracture line (arrow).
AP and lateral films may reveal an obvious fracture; however, oblique films may help to confirm the fracture. Initial radiographs may appear normal; however, 2 to 3 weeks later subperiosteal bone formation may be seen.
The treatment of radiographically confirmed toddler’s fracture consists of a below-knee walking cast for approximately 3 weeks. The treatment of a presumed toddler’s fracture, in which no fracture is visualized on the initial radiograph, is somewhat controversial. Some advocate splinting for comfort and repeat radiographs in 10 days, whereas others recommend casting all children with a history of acute injury, inability to walk or limp, no constitutional signs, and negative radiographs to avoid a delay in treatment.42
Children do not sustain “sprains” and therefore this diagnosis should be used with caution, if at all.43 Salter type I and II fractures can usually be managed conservatively with closed reduction followed by short-leg splint immobilization for 3 to 4 weeks. Nondisplaced distal fibular fractures may also be treated with a removable brace as return to functionality appears to be faster with this treatment approach. Salter types III, IV, and V will likely require operative intervention some time during their management. Pain over the distal fibula physis with a normal radiograph in a child should be managed as a Salter type I fracture.
The fracture pattern varies with age. An example of this age variation is the distal tibia fracture called a “Tillaux fracture,” which is unique to adolescents (Figs. 6–40). As skeletal maturity is achieved and growth plates are beginning to close, the medial distal tibial epiphysis closes prior to the lateral. This creates a fulcrum through which a Salter type III fracture may occur, just lateral to the point of fusion. Because of growth plate involvement and a potential need for open fixation, a prompt orthopedic consultation is indicated. Intra-articular injury is common. CT scans are useful in evaluating complex fracture patterns. Comparison views may help in difficult cases.
Tillaux fracture. The anterior talofibular ligament pulls on the unfused epiphysis of the tibia and results in a Salter III fracture. A. Schematic. B. Radiograph.
Talar dome fractures are far more common in children than in adults. An osteochondral fracture of the talar dome should be highly suspected when evaluating a child who presents with a nonhealing “ankle sprain” or recurrent effusions after an ankle sprain.
Tarsal coalition should be suspected in any child with a history of multiple ankle sprains who demonstrates subtalar stiffness on a physical examination. Tarsal coalition is the abnormal union of two or more bones in the hindfoot and midfoot. This condition may be congenital or acquired because of infection, trauma, or articular disorders. Patients typically present between 8 and 16 years of age. A family history of tarsal coalition may exist. Of all the coalition syndromes, talocalcaneal and calcaneonavicular are the most frequent type. The initial treatment is conservative, consisting of rest and a short-leg cast for 2 to 4 weeks, or the use of a well-molded orthotic and physical therapy. These patients should be referred for appropriate care and follow-up.
Pes planus occurs quite commonly. The incidence of “flat feet” is approximately 7% to 22%. Most patients are asymptomatic. This condition generally does not cause any problems in children. Treatment of symptomatic flat feet with an accessory navicular consists of the use of an orthotic and an exercise program to strengthen the posterior tibial muscles and the peroneal tendons of the foot. Surgery is indicated in some cases.
Freiberg disease involves collapse of the articular surface and subchondral bone of the second metatarsal, presumably from a vascular insult. Although this is most commonly seen in the second metatarsal, it can occur in the third metatarsal. Symptoms are pain and tenderness over the metatarsal head with swelling in this area on clinical examination. Radiographs confirm the diagnosis and treatment consists of decreased weight bearing to the area and a metatarsal pad or orthotic. Surgical excision of loose bodies because of fragmentation of the head is occasionally required.
Osteochondritis Dissecans of the Talus
Most of these lesions are in the middle third of the lateral border of the talus. Lesions are classified into four different stages.
Stage 1: A small area of compression of subchondral bone.
Stage 2: A partially detached osteochondral fragment.
Stage 3: A completely detached osteochondral fragment remaining in the crater.
Stage 4: A displaced osteochondral fragment.
Stage 1 and 2 lesions are treated without surgery using a cast, brace, or strap. Stage 3 medial lesions initially should be treated without surgery, but if symptoms persist, surgical excision and curettage is recommended. Stage 3 lateral lesions and all stage 4 lesions are treated surgically with removal of the lesion.
Sever’s disease, or calcaneal apophysitis, is a common entity occurring in patients between 9 and 11 years of age. The child presents with heel pain, particularly with running, and may use a tiptoe gait or limp. Radiographs are often not helpful; however, the patient is tender on palpation of the calcaneal apophysis. Treatment depends on the severity of the symptoms, the primary role being to rest the heel. In very symptomatic patients, a short-leg walking cast for 10 to 14 days is the treatment of choice.