Musculoskeletal pain of noninflammatory origin is common in childhood and is a frequent cause of referral to pediatric rheumatologists, orthopedic surgeons, sports medicine specialists, and primary care physicians. Noninflammatory causes of pain are more common than inflammatory ones, and early identification and differentiation from other causes of musculoskeletal pain, such as infection or malignancy, are essential to institution of appropriate therapy and avoidance of inappropriate investigations. Children and adolescents with inflammatory arthritis may develop mechanical pain secondary to muscle tendon imbalances exaggerated by anatomical alignment, neuromuscular or proprioceptive deficits, rapid growth, or change in activity level.
Pain Associated with Hypermobility
The term joint hypermobility syndrome (JHS) was first described in 1967 as musculoskeletal symptoms associated with generalized hypermobility without any associated congenital syndrome or connective tissue abnormality. The criteria for hypermobility have evolved over the years, and currently most authors use either the nine-point Beighton scale or the modified criteria of Carter and Wilkinson ( Box 51-1 ). Prevalence estimates vary from 7% to 36% depending on tests and criteria cutoff points. Hypermobility is more common in girls and decreases with age. Asian and African children are more hypermobile than Caucasians. A family history of hypermobility is common.
Modified Criteria of Carter and Wilkinson
Three of Five Are Required to Establish a Diagnosis of Hypermobility:
Touch thumb to volar forearm
Hyperextend metacarpophalangeal joints so fingers parallel forearm
>10° hyperextension of elbows
>10° hyperextension of knees
Touch palms to floor with knees straight
Beighton Scale *
* From P. Beighton, L. Solomon, C. Soskolne, Articular mobility in an African population, Ann. Rheum. Dis. 32 (1973) 413–418.
≥6 points defines hypermobility: touch thumb to volar forearm (one point each for right and left)
Extend fifth metacarpophalangeal joint to 90° (one point each for right and left)
>10° hyperextension of elbow (one point each for right and left)
>10° hyperextension of knee (one point each for right and left)
Touch palms to floor with knees straight (one point)
Other Noncriteria Features of Many Children with Hypermobility:
Put heel behind head
Excessive internal rotation to hip
Excessive ankle dorsiflexion
Excessive eversion of the foot
Passively touch elbows behind the back
Some children with generalized joint hypermobility develop pain. Hypermobile adolescents from the United Kingdom were shown in a prospective study to have a higher risk of chronic widespread pain and a 2-fold greater risk of localized pain in specific joints (e.g., shoulder, knee, ankle/foot) but not the lower back. A significantly higher odds ratio of knee pain was seen in obese youth. Children with benign hypermobility may also have fibromyalgia. The cause of pain in hypermobile children is not known but may be related to joint instability, impaired proprioception and related microtrauma, or a central sensitization and disturbance in the autonomic nervous system. Premature osteoarthritis has been suggested to be a result of hypermobility, but longitudinal studies have not confirmed an association.
Other musculoskeletal conditions reported to be associated with hypermobility include temporomandibular joint dysfunction with disc displacement, patellofemoral pain syndrome (PFP), and frequent ankle sprains. Reduced muscle strength, balance, and head and trunk stability are more prevalent in hypermobile children, suggesting delayed locomotor development. Children with developmental coordination disorder (motor coordination below expected for chronological age and intelligence) are also frequently hypermobile.
The revised Beighton criteria for benign joint hypermobility syndrome (BJHS) in Box 51-2 incorporate the Beighton score plus musculoskeletal and extraskeletal symptoms. These criteria suggest that BJHS is a multisystem disorder, which includes symptoms of chronic pain, autonomic dysfunction (orthostatic intolerance, poor concentration, fatigue), and gastrointestinal dysmotility. While these associations are reported, there is no universal agreement on the causal relationship with BJHS.
A Beighton score of 4/9 or greater (currently or historically)
Arthralgia for longer than 3 months in 4 or more joints
A Beighton score of 1, 2, or 3/9
Arthralgia in 1 to 3 joints or back pain or spondylolysis, spondylolisthesis
Dislocation in more than 1 joint, or on 1 joint on more than 1 occasion
Three or more soft tissue lesions (e.g., epicondylitis, tenosynovitis, bursitis)
Marfanoid habitus (tall, slim, span > height, upper segment/lower segment ratio less than 0.89, arachnodactyly)
Skin striae, hyperextensibility, thin skin, or abnormal scarring
Eye signs: drooping eyelids or myopia or antimongoloid slant
Varicose veins or hernia or uterine/rectal prolapse
JHS is diagnosed in the presence of 2 major criteria, or 1 major and 2 minor criteria, or 4 minor criteria. Two minor criteria suffice if there is an unequivocally affected first-degree relative. JHS is excluded by the presence of MFS or EDS (other than the EDS hypermobility type, formerly EDS III) as defined by De Paepe 1996 and Beighton 1998 criteria, respectively.
It is important that heritable disorders of connective tissue (HDCT) are considered in patients presenting with hypermobility. Several such syndromes are listed in Box 51-3 ; in most, characteristic phenotypes suggest an underlying HDCT, but conditions such as Ehlers Danlos III (hypermobility syndrome), Stickler and Marfan syndromes can be overlooked if they are not specifically considered. The latter should be evaluated using the revised Ghent criteria.
Tall and thin
Arm span greater than height
Lower ratio of upper-body segment to lower-body segment (long legs); normal ratio is 0.85 in whites and 0.92 in blacks
Pectus excavatum or carinatum
Dislocation of the lens of the eye
Aortic root dilatation
Heart murmurs, midsystolic click
Autosomal dominant disorder due to mutations of fibrillin gene on chromosome 15
Major risk of thrombotic events
Autosomal recessive disorder usually associated with cystathionine β-synthase deficiency due to mutations of gene on long arm of chromosome 21
Typical facial appearance: malar hypoplasia, depressed nasal bridge, epicanthal folds, micrognathia
Cleft palate (Pierre Robin sequence)
Severe myopia (may lead to retinal detachment)
Sensorineural hearing loss
Mitral valve prolapse
Autosomal dominant disorder due to mutations of type II collagen gene on chromosome 12
Skin abnormalities: thin, hyperelastic, cigarette paper scars, easy bruising
Dislocation of joints
Rarely, artery aneurysms; hollow organ rupture
Heterogeneous conditions; at least nine types with different inheritance patterns
Fragile bones with multiple fractures and deformities
Different types; usually autosomal dominant inheritance
Involves abnormalities of type I collagen
Characteristic elfin facial appearance
Friendly and loquacious
Initially hypermobile but later become hypomobile without pain
Sporadic and inherited cases due to deletion of elastin allele on chromosome 7
Down Syndrome (Trisomy 21)
Characteristic facial appearance; epicanthal folds
Endocardial cushion defects
Broad hands with simian creases
Brushfield (depigmented) spots of the iris
Usually occurs in a sporadic fashion
Reassurance is the initial treatment of hypermobility. Although hypermobility may enable a child to be a good gymnast or ballet dancer, injuries may be more frequent. Supportive footwear is helpful for many. Some children benefit from a post-activity or evening dose of acetaminophen or a nonsteroidal antiinflammatory drug (NSAID). Older, more severely affected children may be helped by formal physical therapy that focuses on reestablishment of normal muscle power and overall reconditioning. Taping or bracing of troublesome joints and the use of orthotics may be advantageous. Those with more widespread pain may benefit from cognitive behavioral techniques. Children who “crack their knuckles” are frequently hypermobile. Parents are often concerned that this activity might lead to joint damage, but it is probably not a cause of later osteoarthritis.
The flexible flat foot is common in infants; development of an arch with age is part of normal growth. It is defined by a normal arch when toe standing or lying down and flattening on weight bearing. The reported prevalence is higher in young children (up to 60% of 2 to 6 year olds) but reduces to less than 19% by 8 to 13 years of age. Other factors associated with flatfoot include male gender, family history, generalized ligamentous laxity, shoe wearing before 6 years of age, obesity and developmental coordination disorder. A patient with flat feet and hindfoot valgus is shown in Fig. 51-1 .
Children with flexible flat feet are often asymptomatic, but affected preschoolers seen in follow-up at 16 years of age had occasional pains in the neck back knee, leg, or foot. Anterior knee pain was more common in 17-year-old military recruits with flexible flat feet. The Framingham foot study found that men with pes planus had more arch pain and those with pronated feet had more generalized foot and heel pain. Interestingly, pes planus does not appear to be associated with significant lower extremity injuries in young adult athletes or impair athletic performance in children and youth.
Most children do not require treatment unless they develop symptoms or do not acquire an arch by 9 years of age. Those who are symptomatic may benefit from supportive footwear as well as stretching and strengthening exercises. Corrective orthotics may improve symptoms or have no impact. Surgery to lengthen the heel cord is indicated only in the extreme cases in skeletally mature adolescents.
In contrast to the mobile flat foot, a rigid flat foot is always pathological. This is defined by reduced range of motion of the tarsal and subtalar joints and a longitudinal arch that does not increase with standing on the toes. It may result from a tarsal coalition in which a fibrous or bony connection between two or more tarsal bones is present at birth ( Fig. 51-2 ). It occurs in 1% of the population, affects boys twice as often as girls, and is bilateral in up to 80% of patients. There is often a family history of this condition. Ninety percent of cases are calcaneonavicular and talocalcaneal coalitions. Symptom onset usually occurs at the time of ossification: 8 to 12 years of age for calcaneonavicular and 12 to 16 years of age for talocalcaneal coalitions. Children may report ankle pain that is aggravated by activity or frequent “ankle sprains.” On examination, valgus rearfoot and equinus ankle deformities are noted along with restricted and possibly painful subtalar range of motion. The peroneal muscles may spasm from adaptive shortening in response to heel valgus. Radiographs (oblique and axial views) may show calcaneonavicular coalitions, but computerized tomography (CT) or magnetic resonance imaging (MRI) is needed for fibrous or cartilaginous union and other tarsal coalitions (see Fig. 51-2 ). Children with symptomatic coalitions require orthopedic assessment for casting and/or orthoses, physiotherapy, and possible surgical excision of the bony bar.
Genu recurvatum, like pes planus, may be part of a generalized hypermobility syndrome or may occur as an isolated phenomenon. Symptoms are worse with standing or walking and are relieved by rest. Athletes may have particular difficulty. Symptomatic genu recurvatum occurs most commonly in adolescent girls and is associated with popliteal pain and an increased incidence of anterior cruciate ligament injury. Obese children are also more likely to be affected and suffer lower extremity pain. Treatment includes orthotic correction of biomechanical faults, improving knee proprioception, muscle control (especially quadriceps strength) and gait, and maintaining good knee alignment during functional activities.
Pain Associated with Hypomobility
Symptomatic generalized hypomobility (JHypoS) is an entity in which decreased ranges of joint motion and pain in periarticular tissue are probably caused by an increased stiffness in joint ligaments. Physical activity-induced lower extremity pain and habitual toe walking are typically associated with JHypoS, and boys appear to be more frequently affected. Reduced exercise tolerance is associated, which is likely related to a pain-related deconditioned state. Although familial hypomobility has been described, prevalence data are not yet available. This condition may be caused by changes in collagen metabolism, perhaps because of greater hydroxylation of lysine residues in collagen telopeptides due to an upregulation of telopeptide lysyl hydroxylase. There are other relatively uncommon disorders, including hyalinosis and familial fibrosing serositis, in which pain may relate to very stiff joints ( Box 51-4 ). Most children with marked stiffness/contractures due to conditions such as arthrogryposis, Williams syndrome, and cerebral palsy, do not seem to have arthralgias, so careful evaluation for other explanations for pain needs to be undertaken. Treatment of these conditions requires an effective stretching exercise program to allow plastic deformation of collagen tissue.
Diabetes mellitus (diabetic cheiroarthropathy)
Tightening of skin and soft tissues of fingers
Scleroderma and scleroderma-like conditions
Mucopolysaccharidoses and mucolipidoses with dysostosis multiplex
Autosomal recessive inheritance (except in Hunter syndrome, which is X-linked)
Familial fibrosing serositis
Progressive contractures of fingers and toes
Fibrosing pleuritis and constrictive pericarditis
Probably autosomal recessive inheritance
Camptodactyly syndromes (several familial conditions including Blau syndrome)
Flexion contractures of fingers
Beals contractural arachnodactyly syndrome
Cardiac abnormalities unusual
Linked to fibrillin-l-like gene on chromosome 5 (autosomal dominant inheritance)
Multicentric osteolysis particularly of fingers, starting in infancy
Autosomal recessive inheritance
Common Overuse Injuries
Patellofemoral Pain Syndrome
Patellofemoral pain (PFP) is one of the most common knee conditions among children, with a prevalence of approximately 7%. PFP affects active and inactive children, is more common in girls, and is most common during the adolescent growth spurt ( Table 51-1 ). Symptoms usually affect both knees with one side more affected. The etiology of PFP is unknown and believed to be due to biomechanical factors, malalignment of the patella relative to the femoral trochlea, and excessive mechanical loading. The most common presenting complaint is dull, achy peripatellar or retropatellar pain and stiffness during and after activity, and after prolonged sitting with the knee in flexion (“theatre sign”). Pain is worse with weight-bearing sport, stair use, and squatting. True instability does not occur, but patients often report “giving way” due to pain-related reflex inhibition of the quadriceps muscle or deconditioning. On examination, children may have lower extremity malalignment (genu valgum, varum, or recurvatum, leg length discrepancy, femoral anteversion, external tibial torsion, laterally displaced tibial tubercle, pronated subtalar joint), vastus medialis wasting, increased Q-angle (angle formed between the line joining anterior superior iliac spine and center of the patella and the patella and tibial tuberosity), patellar facet tenderness, tightness (hamstrings, quadriceps, iliotibial band, gastrocnemius), and weakness (quadriceps, hip external rotators, abductors, trunk muscles) of the lower extremity muscles. A painful quadriceps setting/grind test (suprapatellar resistance while the patient performs isometric quadriceps contraction with knee in full extension), and patellar compression test (direct compression of the patella into the trochlea) aid diagnosis.
|Age At Onset||Adolescence to young adulthood|
|Sex Ratio||Girls > boys|
|Symptoms||Insidious onset of activity related knee pain, difficulty descending stairs and squatting, need to sit with legs straight (“theatre sign”)|
|Signs||Vastus medialis atrophy, patellar facet tenderness, positive quadriceps setting/grind and patellar compression tests, lateral tracking of patella. Weakness of the quadriceps, hip external rotators and abductors, and trunk muscles.|
The aim of treatment is to correct unbalanced tracking of the patella. Longer pain duration before initiation of treatment is associated with poorer long-term prognosis. Treatment includes activity modification, cryotherapy, short-term NSAID therapy, and physiotherapy. Physiotherapy focuses on patellar tracking exercises, flexibility, and strengthening around the hip and knee. Patellofemoral orthoses, patellar taping, and shoe orthoses (to improve alignment and patellar tracking) may reduce symptoms but have no benefit unless combined with exercise therapy. Box 51-5 shows guidelines for safe return to sport.
Full range of motion (compare the injured part with the uninjured opposite side)
Full or close to full (90%) strength (compare with the uninjured side)
For lower body injuries–able to perform full weight bearing without limping
For upper body injuries–able to perform athletic movements (throwing, swimming, etc.) with proper form and no pain
Always start with aerobic exercise, followed by functional and sport specific skills (jumping, pivoting, etc.), and practice before competitive play.
Patellofemoral instability is more common in children with hypermobility and anatomic variants (ligamentous laxity, patella alta, trochlear dysplasia, external tibial torsion, genu valgum). Children complain of anterior knee pain, episodic giving way and locking, and recurrent swelling. On examination, findings are similar to PFP and the patellar apprehension test (contraction of the quadriceps muscle when the examiner attempts to displace the patella laterally), or frank lateral dislocation may be elicited. Radiographs are recommended to rule out osteochondral fracture associated with patellar dislocation. Treatment is the same as for PFP. Patellofemoral orthoses (stabilization braces) may prevent recurrent episodes of instability. Orthopedic referral is recommended for acute patellar dislocation and recurrent instability. A Cochrane review failed to find evidence to support surgical management over conservative management for acute patellar dislocation. A systematic review found better outcomes for surgical stabilization in patients with recurrent instability.
The knee has normal synovial folds that are residual embryonic remnants persisting from when the knee cavity was a septated structure. Plicas around the knee are common and generally asymptomatic. Occasionally, plica becomes symptomatic due to inflammation from acute trauma or repetitive microtrauma. The mediopatellar plica syndrome is most common; presenting with medial knee pain, patellar snapping, and catching during flexion. The plica may be palpable as a tender thickened band when pressed against the edge of the condyle and there may be localized tenderness at the medial and inferior patellar border. Dynamic ultrasonography has good sensitivity and specificity to detect abnormalities of medial plicae. MRI may show thickening of the plica and any associated synovitis or reactive changes in subchondral bone. Management includes patellar mobilization and massage, physiotherapy, and NSAIDs. Surgical removal of the plica is reserved for recalcitrant symptoms.
Fat Pad Irritation/Impingement (“Hoffa Syndrome”)
The infrapatellar fat pad is richly innervated, and injury may cause anterior knee pain. Impingement of the infrapatellar fat pad between the patella and the femoral condyle may be secondary to direct trauma or acute hyperextension injury. Chronic irritation may be associated with patellar tendinopathy, PFP, or recurrent synovitis. Pain is often present with knee extension, prolonged standing, and kneeling. On examination, there is localized tenderness and swelling in the fat pad with posterior displacement of the inferior pole of the patella. Squatting, active extension of the knee, or passive pressure into extension may reproduce pain. Associated predisposing biomechanical factors include genu recurvatum and anterior tilting of the pelvis. Treatment includes local cryotherapy, taping the patella to reduce the amount of tilt and impingement, physiotherapy, and correcting lower limb biomechanics as in PFP. Surgery is usually not necessary.
“Jumper’s knee,” or patellar tendinopathy, is a common cause of infrapatellar pain in skeletally mature individuals. Maximum discomfort is usually at the inferior patellar pole at the site of the proximal patellar tendon attachment, and is aggravated by jumping. On examination, there is tenderness over the proximal patellar tendon; thickening or nodules may be palpable. There may be secondary PFP. Treatment requires load reduction (activity modification, biomechanical correction), cryotherapy, transfriction massage (massage transverse to the direction of muscle fibers), and progressive eccentric strengthening. In skeletally immature children and adolescents the osteochondroses/traction apophysitis Osgood–Schlatter (OSD) and Sinding–Larsen–Johansson (SLJD) disease present similarly, but tenderness is at the tibial tuberosity and inferior patellar pole, respectively. (See discussion of osteochondroses .)
Iliotibial Band Syndrome
The ITB emanates from the tensor fasciae latae and gluteus medius and maximus muscles, and extends laterally down the leg as a tight band of fascial tissue. It has multiple attachments at the lateral knee before inserting at Gerdy tubercle just lateral to the tibial tubercle. ITB syndrome is associated with repeated knee flexion to or through a 30-degree angle and is common in runners and cyclists. Risk factors include anatomical factors (genu varum, subtalar pronation, internal tibial torsion, leg length discrepancy), weak hip abductors, tight calf muscles, and increased activity.
Adolescents present with activity-related lateral knee pain and tenderness. Occasionally, pain is localized proximally at the greater trochanter due to an associated trochanteric bursitis. On examination, pain and snapping can often be reproduced by palpating over the lateral femoral condyle with passive movement of the knee through a 60-degree arc of flexion; pain is typically maximal at 30 degrees of knee flexion. ITB is often tight with a positive Ober test (patient lying on their side with their affected leg uppermost. Abduct the leg and flex the knee to 90 degrees while keeping the hip joint in neutral position. On release of the leg, the thigh should drop into an adducted position; the thigh will remain abducted in a positive test) for contraction of iliotibial band.
Imaging is not usually necessary; ultrasound and MRI can confirm the diagnosis in difficult cases. Management in the acute phase includes rest, cryotherapy, and analgesics. Physiotherapy is important to correct deficits in muscle strength and mobility and promote a gradual return to activity. In refractory cases, surgical release of the ITB may be required.
Apophysitis and Apophyseal Avulsion Injuries
Apophyseal injuries are common in young athletes, affect boys more often than girls, and are usually secondary to forceful or repetitive traction of the attached muscle. The apophyses of the pelvis appear and fuse later than physes in long bones. The physes are the weakest structures of the immature skeleton, placing adolescents at increased risk of apophyseal injury, especially during a growth spurt. Adolescents have tight soft tissues during rapid growth, placing additional stress on the apophyses. Apophysitis refers to an overuse stress injury at the insertion site of major abdominal and hip muscles around the pelvis. Adolescents usually present with dull, activity-related pain. Radiographs are generally normal or show widening of the affected apophyses. Management includes rest, ice, modified activity, and physiotherapy. Most adolescents return to sport within 4 to 8 weeks.
Apophyseal avulsion fractures occur with sudden forceful muscle-tendon contraction. Common sites of avulsions are at the iliac crest (abdominal muscles), anterior superior iliac spine (sartorius), anterior inferior iliac spine (rectus femoris), ischial tuberosity (hamstrings), and lesser trochanter (iliopsoas) ( Fig. 51-3 ). Adolescents usually present with localized pain, swelling, and reduced range of motion. Pain on resisted contractions of involved muscles, where hip joint motion is restricted, confirms pain is extrinsic to the hip joint. Radiographs demonstrate displacement of the apophyseal center, callus formation, and bony reaction. MRI is useful in suspected avulsion injuries with normal radiographs. Management is usually nonoperative and includes rest, ice, modified activity, and physiotherapy. Most adolescents return to sport within 4 to 8 weeks.
Osteochondritis dissecans (OCD) is an idiopathic lesion of bone and cartilage, resulting in bone necrosis and loss of continuity with subchondral bone. There may be partial or complete separation of articular cartilage with or without involvement of subchondral bone. Proposed etiologies include acute trauma, repetitive microtrauma, genetic factors, vascular insufficiency, ossification variants, inflammation, or normal growth variant. The knee is most commonly affected (75% of cases). Classically, the lateral aspect of the medial femoral condyle is affected, but the lateral femoral condyle, patella, ankle (talus), and elbow (capitellum) are also affected. OCD may be asymptomatic and present as an incidental finding on radiographs, or adolescents may present with activity-related pain and swelling. Locking may be present if there is instability of the fragment. On examination, there may be focal bony tenderness, joint effusion, and evidence of a loose fragment with extension block or palpable loose body. Radiographs may show a radiolucent lesion, subchondral fracture, and a loose body. OCD lesions of the knee can be missed on routine nonweight-bearing anteroposterior and lateral radiographs; tunnel (notch) and axial (skyline patellar profile) views are required to view the articular surfaces of the distal femoral condyles and patella ( Fig. 51-4 ). MRI may show cartilage changes earlier with contrast enhancement of intact cartilage lesions. Staging of lesions has been done based on radiographic, MRI, and arthroscopic appearance. The Berndt and Harty classification characterizes OCD lesions based on radiographical appearance. Stage I reflects small areas of compression, stage II lesions are separate fragments, stage III includes detached hinged fragments, and stage IV lesions are loose bodies. Treatment depends on the site and stage of the lesion and the skeletal maturity of the patient with early lesions in skeletally immature patients having the best prognosis. Conservative treatment (protected weight bearing, immobilization, cryotherapy, NSAIDs, and up to 6 to 18 months of rehabilitation (range of motion, proprioceptive, strength, and endurance exercises) is recommended for stable, nondetached, smaller lesions in children with open physes. Children with symptomatic lesions, salvageable unstable, or displaced OCD lesions require surgery. Approximately one third of all lesions progress to surgery. Surgical treatment is effective in most cases. Treatments include “microfracture” (subchondral drilling), debridement, fragment excision, fragment fixation, osteochondral autograft, osteochondral allograft, and autologous chondrocyte implantation.
Shin Splints (Posteromedial Tibial Stress Syndrome)
Activity-related pain and tenderness along the posteromedial border of the tibia is often referred to as “shin splints” or periostitis. Posteromedial tibial stress syndrome describes the periostitis and fasciitis caused by repetitive traction at the origins of the muscle fascial attachments along the middle and distal posterior medial tibia. Adolescents usually complain of shin pain at onset and toward the end of weight-bearing activity that resolves with rest. Alignment (hindfoot pronation), relative inflexibility (tight gastrosoleus complex, hip abduction), recent increase in activity levels, and change in footwear may be contributing factors. Physical examination demonstrates generalized tibial boney tenderness. Radiographs are normal and radionuclide bone scans show diffuse increased uptake classically at the junction of the middle and distal one third of the posteromedial tibia. The differential diagnoses include stress fracture and posterior compartment syndrome. Management includes rest, ice, modified activity, improving gastrosoleus and posterior tibialis strength and flexibility, change in footwear or orthotic, and correction of any training errors. There is emerging evidence that extracorporeal shockwave therapy (ESWT) may be effective treatment.
Stress fracture occurs when repetitive and excessive stress is applied to normal bone and represents a disturbance between bone resorption and bone regeneration. Stress fractures are believed to be a fatigue fracture or overuse injury and are more common in athletic children who report a recent increase in activity. Low levels of 25-hydroxyvitamin D and the female athlete triad (eating disorders, amenorrhea, osteoporosis) are also risk factors. A study of a prospective cohort of 6712 preadolescent and adolescent girls found that Vitamin D intake was predictive of a lower risk of developing a stress fracture, especially among girls participating in physical activity. The distal to middle third of the tibia is the most common site of stress fracture. The second and third metatarsals are commonly injured in older adolescents and adults and represent the classic “March fracture” seen in the military. Several site-specific stress fractures are high risk for nonunion, complete fracture, or avascular necrosis (AVN), including the proximal fifth metatarsal, tarsal navicular, scaphoid, anterior tibial diaphysis, and femoral neck. Children with stress fractures usually present with progressively worsening pain, aggravated by weight-bearing activity and relieved with rest. Pain may be present at rest or even at night. On examination, the fracture site is tender to palpation and there may be swelling. Early radiographs may be normal and late radiographs detect callus formation ( Fig. 51-5 ), physeal widening, or apophyseal fragmentation. Early lesions are best detected by MRI, which is more specific than radionucleotide bone scan. CT is useful for evaluation of tarsal navicular stress fractures. Management depends on symptoms and the site of injury. Treatment includes activity modification and, if required, a short period of nonweight bearing and immobilization. A pneumatic brace and early mobilization are recommended for tibial stress fractures. High-risk stress fractures often require nonweight bearing and immobilization for 6 to 8 weeks, or surgical intervention.
Little League Shoulder
Overuse injuries of the shoulder are common in young athletes involved in throwing sports, tennis, and swimming. Little league shoulder occurs when excessive traction and rotational torque forces cause microfractures across the proximal humeral physis. It typically affects males between 11 and 16 years of age, and is likely due to the properties of collagen and cartilage in this age group as well as excessive pitching and poor throwing techniques. These athletes usually present with progressive shoulder pain during the throwing motion. Tenderness of the proximal lateral upper arm is common. Many have at least 25 degrees less internal rotation of the dominant shoulder compared to the other side. Radiographs (AP, scapular Y, and axillary views) demonstrate irregularity and widening of the proximal humeral physis. Because similar findings can be seen in asymptomatic pitchers, T2 MRI confirms the diagnosis, demonstrating high intensity signal changes in the adjacent metaphysis. Treatment is almost exclusively nonsurgical, consisting of education, prolonged relative rest from shoulder activity, and rehabilitation to maximize range of motion and strength. Prior to return to play, modification in throwing technique, intensity, and frequency needs to be addressed. Prevention is the key, and, for young baseball pitchers, Little League Baseball Inc. recommends an age-appropriate restriction in number of pitches per day and mandatory rest periods between pitching appearances.
Overuse of the arm related to excessive wrist extension can cause lateral elbow pain, which is commonly called tennis elbow or lateral epicondylitis. One percent to 3% of the general population is affected; both genders equally. The peak prevalence is in the fourth and fifth decades of life. The pathological process consists of tendinosis of the extensor carpi radialis brevis tendon origin. Patients present with lateral elbow pain and maximal tenderness 1 to 2 cm distal to the lateral epicondyle. Resisted middle finger or wrist extension, especially with the forearm pronated and radially deviated reproduces the discomfort. Although generally not required to confirm diagnosis, MRI demonstrates a thickened common extensor tendon with increased signal intensity. Most cases are asymptomatic at 1 year, regardless of treatment. Relative rest, a short course of NSAIDS, and nitric oxide patching followed by rehabilitative therapy (elbow manipulation, strengthening exercises) may provide benefit. Refractory cases treated with a steroid injection at the site of pain derive short-term benefits (under 6 weeks), but high recurrence is reported. Autologous blood injection, platelet-rich plasma, and dry needle injection therapy may be helpful in refractory cases. Surgery is rarely required. Prior to returning to sport, correction of inappropriate sport technique and equipment and the use of a counterforce brace are recommended.
Children are more likely to suffer a valgus compressive injury to the lateral elbow. Repetitive valgus forces during a vulnerable period of growth damages the end-arterial blood supply to the capitellum and can lead to Panner osteochondrosis. Children between the ages 5 and 11 years present with vague lateral elbow pain and stiffness. Radiographs demonstrate flattening and fragmentation of the ossific nucleus, but the condition resolves with no long-term sequelae. OCD of the capitellum is another possible sequela; it may present with lateral elbow pain, swelling, and inadequate extension in older youth. MR imaging best confirms the diagnosis. Rest and immobilization can allow adequate healing, but surgery may be necessary. Prevention of such injuries in all sports is essential. In baseball, Little League Inc. preventive guidelines are recommended.
Overuse of the arm may also result in medial elbow pain or “golfer elbow.” This condition is 7 to 10 times less common than “tennis elbow” but affects a similar age group. In the skeletally mature, this represents a tendinosis at the origin of the flexor/pronator muscles. Localized tenderness at or below the medial epicondyle and pain on resisted wrist flexion and forearm pronation in elbow flexion are characteristic. As with lateral epicondylitis, MRI demonstrates increased signal intensity. Treatment is similar to tennis elbow with recalcitrant cases deriving benefit from ultrasound-guided steroid or autologous blood injection.
Medial elbow pain is more common than lateral pain in skeletally immature throwing athletes. Repeated valgus stress to the medial epicondyle typically presents with local swelling and tenderness. Radiographs may be normal or show fragmentation and sometimes avulsion of the medial epicondyle. MRI may detect stress injury of the medial epicondyle apophysis before plain radiograph changes occur. Treatment consists of rest until symptoms abate, followed by gradual stretching and strengthening to regain full range of motion and power. Surgery is rarely necessary but may be considered for avulsions displaced greater than 5 mm. Prevention of this injury is key.
Wrist Overuse Injuries
Overuse tendon injury may occur in children participating in sports requiring repetitive wrist motion such as throwing, rowing, and racquet sports. DeQuervain’s tenosynovitis, extensor carpi ulnaris tendonitis, and intersection syndrome present with insidious onset of localized pain coincident with increased activity.
Stress injury to the distal radius physis occurs in skeletally immature children participating in hand weight-bearing activity such as gymnastics. Children present with dorsal wrist pain during weight-loading activities (handsprings) and focal tenderness over the distal radial physis. Bone marrow edema may be apparent on MRI before early radiographic changes of widening and irregularity of the physis are apparent. Late radiographic changes may include distal radial deformity or distal ulna overgrowth. Treatment of overuse injuries of the wrist includes ice, NSAIDs, bracing, relative rest, and physiotherapy.
Disorders of the Trunk
Chest pain is not a frequent complaint in the pediatric population. Rowe and colleagues reported that six of 1000 children’s emergency department visits were for chest pain, and boys and girls were equally affected. Twenty-eight percent were diagnosed with chest wall pain; however, only 1% had cardiac causes. One of the most common reasons for chest wall pain is precordial catch syndrome or Texidor twinge, which is a benign and self-limited condition. Affected children have a history of recurrent, well-localized, sharp chest wall pain of sudden onset lasting a few seconds to minutes, with negative findings on examination or laboratory testing.
Costochondritis is a poorly understood condition affecting up to 14% of pediatric patients presenting with chest pain. It is often associated with a history of prolonged cough or chest wall strain. Brief, acute, and stabbing pain affecting one side of the anterior chest that is worse with deep breathing is typical. Tenderness of one or more of the second to fourth costal cartilages is noted without associated swelling, heat, or erythema. Routine laboratory testing is not usually necessary unless the diagnosis is uncertain. The syndrome can be self-limited or chronic and intermittent, but most resolve by 1 year. Treatment is generally directed at pain control with analgesics and NSAIDS, but physical therapy and taping may also help. Refractory cases are occasionally injected with a local anesthetic/corticosteroid into the costochondral region.
This is a localized form of costochondritis that affects one costochondral, costosternal, or sternoclavicular joint. There is associated swelling, warmth, and tenderness of the second or third costochondral junction. Etiology is unknown, but it may be triggered by an upper respiratory tract infection with cough. Plain films are usually normal, but MRI may reveal enlarged and edematous cartilage and contrast enhancement of subchondral bone. Treatment is similar to costochondritis. Injury, septic arthritis, spondyloarthritis, and lymphoma may present similarly and should be excluded.
Slipping Rib Syndrome
This condition is believed to be due to hypermobility of the eighth to twelfth ribs causing the cartilage of one rib to slip superiorly and impinge on the adjacent intercostal nerve. It may be a result of direct trauma or repetitive trunk motion during certain sports. Patients have severe, sharp chest or upper abdominal pain, which may fade over a few hours or persist as a dull ache. Exacerbations can occur with periodic resubluxations precipitated by vigorous physical activity, trauma, or coughing. Physical findings include tenderness of the affected ribs, worsening pain on direct pressure over these ribs, and asymmetry of rib position. Reproduction of the pain, often with a click, occurs when the examiner hooks their fingers under the inferior margins of the affected ribs and pulls anteriorly and superiorly. This “positive hooking maneuver” is usually performed with an intercostal nerve block. Radiological imaging does not confirm the diagnosis but helps to exclude other conditions. Treatment consists of reassurance, avoidance of exacerbating movements, taping, manipulation, and injection of local anesthetic nerve blocks. In severe cases, excision of the anterior rib end and costal cartilage may be curative.
Nonspecific back pain in the general pediatric population is common. A recent meta-analysis of 59 studies found a 40% mean lifetime point prevalence, a 33.6% 1-year period prevalence and a point prevalence of 12%. It may be more common in girls and rates rise with increasing age. Recurrent back pain mirrors that of recurrent abdominal pain with a 6-month point prevalence of 21% to 31%. Most children have mild and self-limited symptoms, but they frequently report avoidance of heavy work at home or at school and greater relaxation time. The etiology of back pain in children is believed to be multifactorial relating to genetic and environmental factors, but body mass index and heavy backpacks do not appear to be associated. Children who have more problems with peers experienced a higher risk of persistent low back pain. Treatment for idiopathic back pain in children has not been well studied. A meta-analysis of physical treatment options suggests the combination of therapeutic physical conditioning and manual therapy is best but education and exercise are also important. Other causes of back pain such as spondylolysis, lordotic pain, disk prolapse, and Scheuermann disease should be considered, especially in young athletes.
Spondylolysis and Spondylolisthesis
Spondylolysis is the most common (47%) cause of back pain in young athletes, especially those participating in activities such as football, rugby, ballet, diving, and gymnastics. Both acute and overuse injuries can occur, although the latter are more common. Repetitive hyperextension causes a stress fracture of the pars interarticularis, most commonly of the fifth (85% to 95%) and fourth (5% to 15%) lumbar vertebrae. Spondylolysis is rare before the age of 5 years and uncommon (6%) in adults. Factors that increase lumbar lordosis (weak abdominal muscles, tight hip flexors, tight thoracolumbar fascia) may increase stress on these posterior spine elements. Other risk factors include European ancestry, family history, and a preexisting developmental spine defect.
Isthmic spondylolisthesis occurs with bilateral pars defects and is defined by forward translation of one vertebra on the next caudal segment, most commonly at L5-S1. This condition is graded based on the percentage of slip of one vertebral body on the vertebra below (grade 1 slip [0% to 25% slip], grade 2 [25% to 50%], grade 3 [50% to 75%] and grade 4 [>75%]). Spondylolisthesis is more common in females, and typically occurs during the adolescent growth spurt. It is less common than spondylolysis, and progression of a slip is rare after skeletal maturity.
The usual presentation of spondylolysis and spondylolisthesis is the insidious onset of extension-related low back pain. Symptoms generally increase over months, and pain may radiate to the buttocks and posterior thigh. If there are radicular symptoms of numbness and weakness, spondylolisthesis and disk herniation need to be considered. On examination, lumbar hyperlordosis, ipsilateral paraspinal muscle spasm, and tight hamstrings with posterior thigh pain on forward flexion are often found. Discomfort is worsened by hyperextension of the spine and this may localize to the affected side on single-leg back extension. There is usually focal tenderness to palpation over the site of the pars lesion and there may be a palpable step-off at the lumbosacral junction with spondylolisthesis. Strength, sensation, and lower extremity reflexes are normal unless a slip causes nerve root irritation.
Radiographs (standing lateral, coned lateral of the lumbosacral junction, AP) are the first line of investigation ( Fig. 51-6 ). Additional oblique views may demonstrate a break in the pars interarticularis (Scottie dog neck), but a low (32%) sensitivity has been demonstrated especially early in the course of this condition. A single-photon emission computerized tomography (SPECT) bone scan is more sensitive and identifies lesions with active bone turnover. CT shows better bony detail and is useful in assessing the healing process; however, the risk of radiation exposure to pelvic organs should be considered. Bone marrow edema on MRI may be useful in detecting early lesions and can also be helpful when neurological symptoms accompany spondylolisthesis.
The goals of management are to achieve bony or fibrous union, relieve pain, optimize and restore function, and prevent or minimize the degree of spondylolisthesis. Initial management includes avoidance of activities that cause pain with a restriction of sport for 3 to 6 months. Physiotherapy is important to reduce lumbar lordosis, strengthen core muscles, and stretch tight hamstring muscles. The use of thoracolumbar orthoses to limit extension and rotation is variable and largely physician and center specific. A meta-analysis comparing bracing to conservative nonbracing treatments suggests both provide a successful outcome 1 year later in 84% of patients. Adolescents can return to sport when they are pain-free with or without a brace, usually within a few months. Standing lateral radiographs are recommended at 4- to 6-month intervals until skeletal maturity. Progressive spondylolisthesis with greater than 50% slip (grade 3 or 4), youth with neurological deficit, or painful nonunion with persistent back pain warrant orthopedic referral.
Lordotic Low Back Pain/Posterior Element Overuse Syndrome
This condition occurs in young athletes during their growth spurt, and is associated with tightening of the interspinous ligaments, thoracolumbar fascia and tendinous attachments on the spine. It is a diagnosis of exclusion. Athletes typically complain of low back pain with activity, especially in sports that require repetitive hyperextension of the lower back. As a result, traction apophysitis, impingement of the spinous processes, and even pseudoarthrosis of the developing vertebrae may occur. Physical examination demonstrates tight hamstrings and pain on back hyperextension. Radiographs can be used to rule out other etiologies. Physical therapy strategies used for spondylolysis are usually effective.
Lumbar Disk Herniation
Discogenic pain has been estimated to occur in about 11% of pediatric athletes, especially those over 12 years of age. Ninety-two percent of affected adolescents experience herniation at the L4-5 or L5-S1 regions. Trauma from collision sports or strength training is often associated with disc protrusion in young athletes, especially those with preexisting spinal deformity (scoliosis, lumbarization/sacralization, canal narrowing) or those with lumbar Schmorl nodes and Scheuermann disease.
Low back pain with or without sciatica is often noted, but overt neurological deficits are uncommon in this age group. Coughing, sneezing, and bending may aggravate the pain. Examination reveals limitation of forward flexion, and over 60% have an abnormal straight-leg test with either localized pain or radicular features. Adolescents may assume a scoliotic posture as a compensatory attempt to relieve nerve root irritation. MRI confirms the diagnosis, with herniated disc material often larger than in adults at the L4-L5 or L5-S1 region. Careful inspection for apophyseal fracture is recommended, especially in youth with large or central herniations.
Conservative treatment with education, rest, analgesics, and physical therapy is successful in most cases. Operative therapy is indicated for those with persistent or progressive neurological deficits. Over 90% of surgically treated adolescents achieve symptom relief; however, reoperation is required in 20% at 10 years and 26% at 20 years postoperatively.
Diskitis is a rare but well-recognized entity affecting toddlers and young children typically between the third and fourth lumbar vertebrae. The pathogenesis is unclear but may reflect self-limited infectious or inflammatory causes. Children may present with back pain, limp, neck stiffness, irritability, and gastrointestinal upset. Toddlers often refuse to stand or sit. Tenderness on palpation of the spinous processes is infrequently found, but the child may refuse to bend down to pick up an object. These poorly localized symptoms and the normal or mildly elevated complete blood count and inflammatory markers contribute to delays in diagnosis. Plain radiographs demonstrate disk space narrowing and irregular endplates of adjacent vertebrae by 10 days; bone scan and MRI have excellent sensitivity, but MRI can also exclude abscesses and spinal tumors. Treatment consists of antiinflammatory agents, antibiotics, and immobilization. The natural course of the disease is benign with the majority being asymptomatic by three weeks. Chronic spinal restriction may develop and persistent intervertebral narrowing on radiographs is common, hence ongoing follow-up is suggested.
Calcific diskitis is a relatively uncommon childhood condition that presents with acute onset of neck pain, torticollis, and calcification of the cervical or thoracic intervertebral disks. The etiology is unclear, but interruption of a tenuous blood supply is suggested. Plain radiographs and MRI are usually diagnostic.
Scheuermann disease is the most common cause of a structural kyphotic deformity in adolescence with an incidence of 0.4% to 10%. It is most frequently diagnosed between the ages of 12 and 17 years, and is more common in boys. The pathogenesis is unclear, but disorders in endochondral vertebral ossification or collagen aggregation, and biomechanical abnormalities may play a role. Eighty percent of patients are asymptomatic and concerned about cosmetic appearance, but pain may be noted with activity, especially in athletes with high demands on their back. The most common “thoracic” type consists of over 40 degrees of kyphosis usually between T7 and T9. It is not reducible with back hyperextension or by lying supine, which is in contrast to postural kyphosis. It may be associated with nonstructural hyperlordosis of the cervical or lumbar spine with greater rates of back pain and risk of spondylolysis. Tightness of the thoracolumbar fascia and hamstring muscles has been noted. Neurological deficits are rare, and cardiopulmonary insufficiency occurs only with severe curves measuring greater than 100 degrees. Classic standing lateral radiological features include anterior wedging of at least three adjacent vertebral bodies each by 5 degrees or more, end plate irregularities, loss of disk space height, and Schmorl nodes ( Fig. 51-7 ). The infrequent thoracolumbar subtype is associated with greater pain and restriction in exercise. It is more likely to progress into adulthood.