Evaluation of the immobile arm in children

INTRODUCTION — This topic will discuss the approach to the child with an immobile arm. Radial head subluxation (nursemaid’s elbow) is discussed separately. (See "Radial head subluxation (pulled elbow): Evaluation and management".)

BACKGROUND — An immobile arm is a relatively common complaint in pediatrics evaluated in both the emergency department and primary care provider office. An infant or child is not moving the limb either due to current or recently resolved pain or weakness and can be considered to have an upper extremity equivalent of a "limp". Since many of these children are preverbal and fearful of strangers, the evaluation may be challenging. Radial head subluxation ("nursemaid's elbow") is by far the most common cause of arm immobility in children younger than six years of age, however, children with much more serious pathology may present with this complaint [1,2]. By using historical information, physical findings, selective radiologic studies, and laboratory tests, children with an immobile arm can be appropriately diagnosed and managed.

DIFFERENTIAL DIAGNOSIS — An immobile arm most frequently results from radial head subluxation or an injury after a fall. The causes of an immobile arm are presented in the table (table 1).

Life and limb-threatening causes — Although these causes of an immobile arm are presented first and should always be considered, other than trauma, they are quite rare.

Complicated fracture or dislocation — Children with fractures or dislocations typically present with a history of trauma and have focal tenderness, swelling, or deformity. Although uncommon, associated neurovascular compromise or an open fracture may be present and require emergent intervention. (See "Distal forearm fractures in children: Diagnosis and assessment" and "Midshaft humeral fractures in children" and "Supracondylar humeral fractures in children".)

Child abuse — In the preverbal child, the history of trauma may be absent either because it was unwitnessed or inflicted by a caretaker who is not forthcoming. Careful physical examination of the child often identifies other signs of inflicted trauma (table 2). In addition, inflicted fractures may have characteristic findings on radiographs. Identifying inflicted injuries is crucial to preventing further, potentially more serious injuries. (See "Physical child abuse: Recognition" and "Orthopedic aspects of child abuse".)

Bone or joint infections — Bone or joint infections are an uncommon cause of immobile arm. Patients often (but not uniformly) have associated history of fever. The onset of arm disuse is often less abrupt than with trauma. There is frequently associated paradoxical irritability (increased crying when being held), localized swelling, warmth and tenderness; infected joints usually have limited, painful range of motion. (See "Bacterial arthritis: Clinical features and diagnosis in infants and children", section on 'Clinical features' and "Hematogenous osteomyelitis in children: Clinical features and complications", section on 'Clinical features'.)

Necrotizing cellulitis or fasciitis — Necrotizing soft tissue infections in children are most commonly caused by group A streptococcus; other agents include s. aureus and anaerobic organisms. Predisposing factors include skin trauma (eg, laceration, burn, surgery) and varicella, although skin may be intact. Children are usually febrile and toxic and the affected area is typically erythematous (without sharp borders), swollen, warm, shiny and exquisitely tender, often with pain out of proportion to the physical exam findings. Advanced cases may show blue-gray skin with cutaneous gangrene. Compartment syndrome and complicating myonecrosis may occur and CPK is often elevated. (See "Necrotizing soft tissue infections", section on 'Necrotizing fasciitis' and "Necrotizing soft tissue infections", section on 'Diagnosis'.)

Stroke — Stroke is a rare cause of arm weakness in children and typically presents with abrupt onset of hemiparesis (rather than isolated arm paresis). Although stroke may affect the arm more than the leg, suggesting a monoplegia, careful examination may reveal mild leg weakness, deep tendon reflex abnormalities or extensor plantar response. Stoke may also be associated with headache, seizure, altered mental status or speech difficulty. Children with sickle cell disease, structural cardiac disease, and coagulation disorders are predisposed. (See "Ischemic stroke in children and young adults: Epidemiology, etiology, and risk factors", section on 'Etiologies and risk factors in children'.)

Tumor or malignancy — Rarely, a child with a neoplasm or malignancy may have decreased arm movement due to pain, either from tumors of bone, cartilage or muscle, or from neoplastic infiltration of the bone marrow. Associated pathologic fractures may be present. Typically less abrupt in onset, there may be a history of fever, malaise, or weight loss and localized tenderness or swelling may be present. With leukemia or neuroblastoma, abdominal mass, hepatosplenomegaly or pathologic adenopathy may be present. Rarely, tumors impinge on nerves or the brachial plexus, causing weakness (with or without pain) as the presenting symptom. (See "Overview of common presenting signs and symptoms of childhood cancer", section on 'Bone and joint pain'.)

Common conditions

Radial head subluxation (nursemaid’s elbow) — Radial head subluxation (RHS) is by far the most common cause of arm disuse and is a common elbow injury that is unique to young children, typically those younger than five years (peak incidence age two to three years). The classic mechanism involves a sudden pull of the arm (figure 1). However, this mechanism is reported in less than two-thirds of patients; RHS is also caused by other mechanisms including falling and twisting, and it is not uncommon to have no history of trauma. The child with RHS typically holds the affected arm slightly flexed (often in the lap) with the forearm pronated and without spontaneous arm movement. The child is usually not distressed unless the elbow is moved (figure 2). There is typically no reproducible tenderness, warmth or swelling (best evaluated while distracting the child). (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Evaluation'.)

Fracture — Fracture of the clavicle or arm may lead to arm disuse. In the neonate, this may be due to a difficult delivery. In the child there is typically a history of trauma with moderate to severe pain and examination reveals local swelling and tenderness. (See "Clavicle fractures", section on 'Pediatric considerations' and "Distal forearm fractures in children: Diagnosis and assessment" and "Midshaft humeral fractures in children" and "Supracondylar humeral fractures in children".)

Soft tissue injury — Children with soft tissue injuries usually present with a history of trauma and may have swelling, tenderness, or a contusion on exam. If obtained, radiographs show no bony abnormality. Rarely, direct neurologic injury may cause neurologic deficits.

Other causes

Hemoglobinopathy — Children with sickle cell disease may present with decreased arm use because of stroke or vasoocclusive crisis, causing ischemia or infarction of bone marrow with acute bone pain. Long bones are commonly affected; however, young children frequently have involvement of the small bones of the hands and feet (dactylitis). Usually, no precipitating events are identified. The child typically has pain with localized tenderness and may have swelling of the involved areas. There may be associated warmth. If febrile, it is important to consider septic arthritis and osteomyelitis as children with sickle cell disease are susceptible to infection, and the clinical findings may overlap with bone infarction. (See "Overview of the clinical manifestations of sickle cell disease", section on 'Acute painful episodes' and "Overview of the clinical manifestations of sickle cell disease", section on 'Stroke and TIA'.)

Inflammatory process — Nonseptic arthritis may cause decreased arm use, and can be due to rheumatologic diseases, postinfectious causes, or, less commonly in the upper extremity, Lyme disease. In addition to a swollen, tender joint, children with inflammatory arthritis often have other findings of systemic disease including multiple joint involvement, rash, fever, adenopathy, heart murmur, hematuria or bloody stools. If the examination suggests an inflammatory arthritis but cannot exclude a septic process, then arthrocentesis is necessary for definitive diagnosis. Rarely, myositis (due to infection, injury, autoimmune or drug) can cause localized muscle tenderness and weakness leading to arm disuse. (See "Evaluation of the child with joint pain and/or swelling".)

Congenital syphilis — Untreated infants with congenital syphilis may avoid movement of the upper extremities because of pain caused by osteochondritis or pathologic fracture (pseudoparalysis of Parrot) and typically present in the first months of life. Associated clinical findings may include hepatosplenomegaly, syphilitic rhinitis ("snuffles"), maculopapular rash, and generalized lymphadenopathy. Long bone films and serologic tests for syphilis can establish the diagnosis. (See "Congenital syphilis: Clinical manifestations, evaluation, and diagnosis", section on 'Early congenital syphilis' and "Congenital syphilis: Clinical manifestations, evaluation, and diagnosis", section on 'Evaluation and diagnosis'.)

Bleeding disorder — Children with hemophilia or other bleeding disorder may have hemarthrosis or hematoma with minimal trauma. The child will typically have a history of a bleeding disorder (although not with the first presentation) and may or may not have a history of trauma. The affected joint is swollen and tender with limited range of motion but there is typically no fever or other systemic symptoms. (See "Clinical manifestations and diagnosis of hemophilia", section on 'Joints and muscle'.)

Conversion disorder — Patients with weakness due to a conversion disorder are typically older children or adolescents and commonly demonstrate a notable lack of concern for their impairment. Their examination is often illogical both anatomically and physiologically. Discontinuous resistance during testing of power or give-way weakness may exist. Muscle wasting is absent, and reflexes are normal. Conversion disorder should be diagnosed only after organic causes have been ruled out. (See "Functional neurological symptom disorder (conversion disorder) in adults: Terminology, diagnosis, and differential diagnosis", section on 'Diagnosis'.)

Complex regional pain syndrome (reflex sympathetic dystrophy) — Children with complex regional pain syndrome (CRPS) have pain to light touch and decreased movement that typically occurs in a single extremity (more commonly lower). There may or may not be history of preceding trauma. Onset of disuse and pain is usually less abrupt than with trauma, worsens over time and is unimproved or worsened by immobilization. Children with CRPS often have associated decreased skin temperature, edema and cyanosis, with some exhibiting hyperhidrosis. Erythema and fever are typically absent. (See "Complex regional pain syndrome in children", section on 'Clinical manifestations'.)

Other neurologic conditions

Todd paralysis — Todd paralysis is a transient focal weakness that occurs after a seizure. The paralysis may be partial or complete. It is typically unilateral and although often a hemiparesis, it may be more prominent in one extremity. (See "Seizures and epilepsy in children: Clinical and laboratory diagnosis", section on 'Behavior after the event'.)

Complex migraine — Focal motor deficits, usually hemiplegia, may occur during a classic migraine attack. The evolution of symptoms is variable but often includes scotomas, unilateral dysesthesias of the hand and mouth and unilateral weakness (may involve only the arm and face, sparing the leg). These non-headache symptoms may precede the headache by 30 to 60 minutes. Other features of migraine are often present, and typically include a throbbing frontotemporal headache contralateral to the affected hemisphere, as well as nausea and vomiting. The neurologic symptoms typically last less than 24 hours. First episodes of hemiplegic migraine should only be diagnosed after other causes of acute stroke have been excluded by brain imaging. (See "Hemiplegic migraine".)

Acute flaccid myelitis — Since 2014, the similar term "acute flaccid myelitis" (AFM) has been used to describe a specific condition recognized in outbreaks in the United States and Europe. These outbreaks have been associated with circulating enterovirus D68 and have caused significant public health concerns. The majority of patients with AFM have upper respiratory symptoms or fever in the days or weeks preceding the onset of weakness. Once neurologic symptoms begin, the evolution of weakness can occur over hours to days. Some have cranial nerve dysfunction, bowel or bladder dysfunction, and/or sensory alterations. Weakness in at least one upper extremity occurs in approximately 80 percent of patients and may be isolated. However, weakness of other limbs is typically present. The diagnosis of AFM requires a clinical phenotype that includes acute flaccid weakness and magnetic resonance imaging (MRI) of the spinal cord that reveals predominantly gray matter involvement. The diagnosis does not require the identification of enterovirus D68, but testing for the virus is recommended for public health purposes. The evaluation of patients with suspected acute flaccid myelitis is discussed in detail separately. (See "Acute flaccid myelitis".)

Brachial plexus pathology — Brachial plexus abnormalities are unusual causes of an immobile arm. Typical etiologies are determined by patient age as follows:

●Neonatal brachial neuropathy – Brachial plexus injuries in the newborn are caused by excessive traction during delivery. Erb palsy involves the upper roots (C5/6), causing the arm to be adducted and internally rotated, elbow extended, forearm pronated, and wrist flexed with preservation of hand movement. Klumpke palsy, an injury to the lower roots (C8/T1) is much rarer, manifesting as isolated hand paralysis. Severe damage to all C5-T1 roots causes a flail arm and Horner syndrome. (See "Brachial plexus syndromes", section on 'Neonatal brachial plexus palsy'.)

●Postnatal brachial neuropathy – Although unusual, impairment of the brachial plexus is most often caused by trauma (traction or pressure), although tumor, inflammation or ischemia may rarely be responsible. Onset of symptoms may be acute or insidious and include weakness and pain, less commonly sensory loss. Examination may reveal weakness, atrophy, sensory loss, or diminished reflexes. (See "Brachial plexus syndromes", section on 'Traumatic plexopathies'.)

Mononeuropathy — Radial, ulnar, or median nerve dysfunction causes weakness or sensory symptoms in the distal regions of innervation and is most commonly due to trauma (fracture or compression). Axillary neuropathy most commonly results from shoulder injury, direct trauma or pressure, and manifestations include numbness of the outer shoulder and deltoid weakness. (See "Overview of upper extremity peripheral nerve syndromes".)

EVALUATION

History — A comprehensive history helps narrow the extensive list of possible causes in the child with an immobile arm (table 1).

●Patient age – Patient age helps narrow the differential diagnosis as follows:

•Neonates may present with birth complications (clavicle fracture, brachial plexus injury). If not from birth, arm disuse in this patient population and young infants up to one year of age is potentially concerning for significant pathology (eg, central nervous system abnormality, child abuse, septic arthritis, or osteomyelitis). It is important to note that infants may not mount a febrile response to infection and may only have nonspecific symptoms (eg, increased sleeping, lethargy, diminished feeding, irritability). Of note, congenital syphilis many cause pseudoparalysis in infants in the one to three month age range with or without fever.

•Children one to five years of age most commonly have radial head subluxation (RHS, nursemaid's elbow) or a fracture of the clavicle, humerus, or forearm bones, as the cause of an immobile arm.

•Children older than five years of age and adolescents typically have a fracture or soft tissue injury.

●Onset – Acute arm immobility is usually due to trauma although acute onset may occur with some of the rare neurologic causes (eg, complex migraine, Todd paralysis, stroke). Subacute disuse is more typical of infection or a systemic disease such as an inflammatory arthritis, vasoocclusive crisis, or malignancy. If the patient is an infant, it should be determined whether the arm disuse began abruptly at birth, suggesting either brachial plexus injury or clavicle fracture sustained during a difficulty delivery, or more gradually in the first three months of life, as may be seen with pseudoparalysis of Parrot caused by congenital syphilis.

●Trauma – A history of a pull on the arm or trauma is typically present for children with RHS, fracture, or soft tissue injury. Details of the event may provide clues to the type of injury incurred: a fall onto an outstretched hand may cause soft tissue injury (eg, contusion, strain, or sprain) or an elbow, wrist or forearm fracture, whereas a sudden arm pull by a caregiver can cause RHS. It is important to note that many children with RHS may have a mechanism of injury other than traction.

●Pain – Pain is present for the majority of diagnoses but may be absent in RHS (if the arm is not moved) and with weakness due to rare neurologic processes. Location and duration of pain are important to elicit and can aid in diagnosing the etiology of the arm immobility.

●Other findings – Associated signs and symptoms can help suggest specific etiologies:

•Fever, malaise, rash and weight loss can be seen in infectious, inflammatory or oncologic diseases.

•History of sickle cell disease, bleeding disorder, structural cardiac disease, or underlying inflammatory process (eg, rheumatologic disease) would suggest complications of the underlying illness as a possible etiology of arm disuse.

•Headache, seizure, paresthesias, weakness, or other nervous system abnormality would point to a neurologic cause.

Physical examination — Although a full physical examination is important for evaluation of the child with arm disuse, examining a young child can prove challenging because they often cry when approached or touched by a stranger. Observation and inspection, sometimes from a distance of several paces, can provide information that might otherwise be unobtainable.

●General appearance – Children with radial head subluxation typically appear comfortable as long as the arm is not moved. Significant pain at rest suggests fractures; or less commonly, arthritis, osteomyelitis, or sickle cell disease. Fever or ill appearance are concerning for an infectious cause.

●Examination of the affected arm – The following findings help in narrowing the differential diagnosis:

•Position – A child with RHS often holds the arm pronated and slightly flexed with obvious diminished movement although typically without apparent discomfort (figure 2). A child with neurologic abnormality may hold the arm limply at the side of the body. A child with a fracture may support the injured arm using the unaffected arm.

•Inspection – Evaluate for deformity, redness, swelling or bruising which may be evidence of localized trauma or inflammation.

•Palpation – The arm should be palpated from the sternoclavicular joint to the fingers to identify areas of warmth, swelling or tenderness (often best accomplished in the younger child while they are being distracted). Patients with RHS typically have no reproducible tenderness at rest but often have poorly localized pain with movement. The patient with no tenderness who does not have RHS yet is not moving the limb should be closely evaluated for neurologic impairment. For children in whom the examiner is unable to distinguish whether the reaction to palpation is secondary to pain as opposed to stranger anxiety, it may be helpful to have the parent or caregiver palpate the arm while the examiner observes from across the room or the doorway.

•Joint exam – Joints should be assessed for focal warmth, redness, tenderness and range of motion; however, if a history of trauma is present manipulation can be deferred until an acute fracture has been excluded by radiograph.

•Neurovascular status – Careful assessment should be performed. Observation of the younger child's reach and grasp for an interesting object can provide information about active range of motion and neurologic function.

●General examination – A thorough general exam, particularly for children without an obvious injury should be performed to assess for a rash, other joint abnormalities, hepatosplenomegaly, adenopathy, and neurologic findings.

Ancillary studies

Imaging — Children with probable radial head subluxation (RHS) based upon a consistent history and physical examination and no features suggestive of another etiology do not require imaging for diagnosis or prior to attempted reduction as long as there is no focal tenderness present on palpation. Radiologic imaging is indicated only if other diagnoses are being considered. The procedure for reducing a RHS is discussed separately. (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Management'.)

●Plain radiograph – Plain radiographs of the arm may be helpful in the diagnosis of fracture, osteomyelitis, congenital syphilis, and bone tumors. The initial radiographs in children with Salter-Harris type I fractures, RHS, early osteomyelitis and septic arthritis are often normal. Comparison views should not routinely be obtained as two studies showed diagnostic accuracy was not improved by obtaining comparison views in children with elbow trauma. The decision to obtain comparison views should be individualized depending upon the clinician's experience and the diagnosis in question [3,4]. (See "General principles of fracture management: Fracture patterns and description in children", section on 'Salter I (Ogden IA-C)' and "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Imaging' and "Congenital syphilis: Clinical manifestations, evaluation, and diagnosis", section on 'Radiographic abnormalities'.)

●Ultrasonography – Ultrasound is an excellent technique for identifying joint effusions and could be considered if the diagnosis is in question or to guide joint aspiration. (See "Bacterial arthritis: Clinical features and diagnosis in infants and children", section on 'Imaging'.)

●Magnetic resonance imaging (MRI) – MRI of the involved extremity may be useful for diagnosing osteomyelitis, occult fractures infections, trauma of the soft tissues, or bone tumors. Brain MRI will aid in the diagnosis of central nervous system conditions.

●Radionuclide scan – Bone scintigraphy will reveal uptake at areas of increased metabolic activity before bony changes are visible on radiography and thus may be useful to localize bone pathology such as osteomyelitis or occult fracture. However, it is less sensitive and specific than MRI. It is thus most useful when MRI is not available and imaging other than plain radiography is needed to make the diagnosis; the area of suspected infection cannot be localized; or multiple areas of involvement are suspected.

●Computed tomography (CT) – CT is rarely required but can be useful to evaluate suspected acute central nervous system pathology, or to further delineate bony/soft tissue pathology.

Laboratory evaluation — The laboratory evaluation of the child with immobile arm should be directed by the history and physical examination findings and is not indicated for the vast majority of children who have radial head subluxation or trauma as the cause of arm immobility.

●Blood studies – Complete blood count (CBC), acute phase reactants (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) and blood culture and in young infants serologic studies for syphilis are useful when infection, inflammation, oncologic diseases or syphilis are possible causes of the immobile arm. Laboratory tests for sickle cell disease or bleeding disorders should be sent if these diagnoses are being considered and not yet diagnosed. (See "Clinical manifestations and diagnosis of hemophilia", section on 'Diagnostic evaluation' and "Congenital syphilis: Clinical manifestations, evaluation, and diagnosis", section on 'Laboratory abnormalities' and "Diagnosis of sickle cell disorders".)

●Synovial fluid analysis – Joint aspiration is warranted if septic arthritis is suspected. Synovial fluid analysis should include white blood cell count, Gram stain, cultures and measurement of protein and glucose. (See "Bacterial arthritis: Clinical features and diagnosis in infants and children", section on 'Synovial fluid'.)

APPROACH — The approach to a child with an immobile arm is described in the algorithms (algorithm 1A-C).

Mechanism of injury — The clinician should first determine whether the arm became immobile after being pulled or another type of trauma such as a fall or direct blow. For patients with an unwitnessed mechanism, history will be lacking. Site of injury (if possible) and neurovascular integrity should be established.

Classic radial head subluxation — If the history is classic for radial head subluxation (ie, the arm was pulled), the patient is holding the arm pronated and slight flexed, and there is not localized tenderness or swelling, then the clinician may attempt reduction (occasionally requires more than one attempt). If the child does not regain full use of the arm quickly, as in all other cases of trauma, radiographs should be obtained (algorithm 1A). (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Diagnosis' and "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Management'.)

Trauma with arm tenderness — Children with a history of trauma and tenderness on physical examination of the arm should undergo plain radiographs (algorithm 1A). These images may reveal a fracture or dislocation. Normal plain radiographs often imply soft-tissue injury, but reproducible tenderness or swelling overlying the epiphysis implies a Salter-Harris I fracture. Not infrequently, a child with radial head subluxation may have an atypical clinical picture; if a child younger than four to five years has radiographs that exclude a fracture, but the patient is holding the arm in a characteristic position without focal tenderness, an attempt at reduction should be performed. (See "Radial head subluxation (pulled elbow): Evaluation and management", section on 'Management'.)

Neurologic abnormality — Although quite rare, a child not moving the arm who has no tenderness, full passive range of motion of all joints, and no evidence of radial heal subluxation is concerning for an underlying neurologic condition (algorithm 1B). Children with neurologic abnormalities should be evaluated urgently to localize the site and cause of the impairment (eg, central versus peripheral process) and to determine if they have an underlying predisposition for stroke (eg, sickle cell disease, hypercoagulable state, or congenital heart disease). Appropriate imaging and subspecialist consultation (eg, neurologist or neurosurgeon with pediatric expertise) should occur. The rare child or adolescent with neurologic findings that are illogical anatomically and physiologically may have a conversion disorder. In the neonate, distinguishing between findings from birth and those acquired post-natally is an important distinction.

Evidence of localized inflammation or systemic disease — Patients with sickle cell disease or factor deficiency are likely to have a vasoocclusive crisis or hemarthrosis, respectively (algorithm 1C). Patients with fever or other findings of systemic inflammation warrant measurement of a complete blood count, blood culture, and inflammatory markers (eg, erythrocyte sedimentation rate, C-reactive protein) and plain radiographs (although occasionally some children may have fever from an unrelated source, eg, viral illness). Other laboratory studies may be indicated depending upon the clinical findings (eg, creatine phosphokinase in patients with possible myositis; serum lactate dehydrogenase and uric acid if concern for oncologic process). Based upon the history, physical examination, imaging and laboratory studies the child may have infection (eg, septic arthritis, osteomyelitis), malignancy, rheumatologic, or noninfectious inflammatory disease, for which the clinician can begin specific management.

No trauma or concern for neurologic, infectious, or systemic disease — Patients without a history of trauma and with no evidence for neurologic, infectious, or systemic disease should undergo plain radiographs to evaluate for bony abnormalities (eg, fracture, dislocation, tumor) (algorithm 1A). An attempt at reduction of a radial head subluxation (RHS) is warranted for children with normal radiographs who are younger than five years. If there is no improvement, then the diagnosis is most likely either a soft tissue injury or an unreduced RHS. These patients may be immobilized in a sling or splint and should undergo evaluation in one to two days.

If radiographs are normal in the older child, they may have a soft tissue injury, complex regional pain syndrome, or conversion disorder.

Regardless of age, an indolent pathologic process or occult fracture may be present in patients without a clear etiology. Obtaining blood work may be appropriate if occult infectious or inflammatory processes are suspected. In all such patients, close follow-up should be assured and clear instructions given to caretakers for reasons to return to the emergency department.

SUMMARY

●An infant or child who is not moving the limb either due to pain or weakness has an upper extremity equivalent of a "limp". (See 'Introduction' above.)

●Radial head subluxation ("nursemaid's elbow") is by far the most common cause of arm immobility in children one to five years of age. However, children with much more serious pathology may present with this complaint. (See 'Differential diagnosis' above.)

●Correct diagnosis of the underlying cause for an immobile arm in a child depends upon a careful history, physical examination, and, in selected patients, imaging studies and laboratory testing. (See 'Evaluation' above.)

●The table and algorithm provide a list of conditions and an approach to evaluating a child with an immobile arm (table 1 and algorithm 1A-C). (See 'Approach' above.)