Prognosis 95% of cases of physiological varus resolve with age. Osteochondritis dissecans of the knee Occurs when an area of subchondral bone becomes avasc ular and frag- ments and separates from the underlying bone. May involve the overlying cart ilage, leading to mechanical problems (e.g. loose bodies) and joint in- congruity. Most com monly involves the lateral aspect of the medial femo- ral condyle. It may progress to early degenerative osteoarthritis. \200 Risk trauma, ischaemia, abnormal epiphyseal ossi \201 cation. Clinical Knee swelling after activities, but no history of acute trauma or injury. May be tender over affected articula r cartilage of medial femoral condyle if knee is fully \202 exed. Disease progression: th e overlying articular cartilage is usually intact in younger children and the bone heals as revascularization occurs. The risk of articular fracture with separation and loose body fo rmation increases with increasing age, larger lesions, and a weight-bearing location. factors: adolescents (10 \200\22315yrs). Boys > girls. Often secondary to features: non-speci \201 c knee pain, +/ \200\223 locking and +/ \200\223 stiffness. Investigations X-rays of knee in AP, lateral, and notch views to assess femoral condyles. M RI may be useful for determining integrity of articular cartilage and de \201 ning whether synovial \202 uid is behind the lesion. Treatment Depends on patient age, size, and stability of fragment. Usually a short treatmen t with rest, anti-in \202 ammatory drugs, and splintage will suf \201 ce. However, it may require surgery: \200 as above, including observation with periodic X-rays Non-operative: and MRIs to assess degr ee of healing. Bracing and restricted weight- bearing/activities if signi \201 cant growth remaining. Operative: adolescent with minimal growth left/loose lesion \200\224 arthroscop ic assessment with possible debridement and microfracture through subchondral plate to prom ote revascularization and healing. Fixation of large fragments. 20_McClure_20.indd 756 11/14/2012 3:24:06 PM KNEE DISORDERS 757 Prognosis Worse with large lesions in lateral femoral condyle in older children. Note: Osteochondritis dessicans may occur in other major joints in- cluding the elbow (capi tellum) and less often the lateral condyle of the patella. 20_McClure_20.indd 757 11/14/2012 3:24:06 PM CHAPTER 20 Bones and joints 758 Orthopedic trauma Trauma is the most common cause of childhood deaths. It is often due to f alls especially in the home environment (home> sports > school > road traf \201 c accident ). Road traf \201 c accident is the leading cause of death. NAI should be con- sidered (see b pp.527, 923, 1000). Fractures Generally boys > girls with a peak incidence at 12yrs of age, although speci \201 c injuries peak at different ages, e.g. NAI at 1yr, femoral fractures at 3yrs, pedestr ian vs car at 6yrs, lateral condyle/supracondylar fractures at 7yrs, physeal injury at 11 \200\22312yrs. 4% are multiple fractures. Children \200\231s fractures usually are more fre quent in summer than in winter. Principles of management \200 \200 b Chapter 4). Stabilize according to resuscitation principles (see Full history (including nature of injury, left/right handedness) and examination. Is the fracture open/closed? Is t he limb neurovascularly intact? Is there a compartment syndrome? Is the associated joint di slocated? Splint limb for comfort; analgesia; elevate. X-ray affected bone +/ \200\223 join t above and below. Liaise with orthopedic team. \200 \200 \200 \200 \200 Complications Early \200 Neurovascular radius fractures, median/ulnar nerve paraesthesia with supracondylar fracture s, radial nerve in humeral shaft fractures, common peroneal nerve with proximal \201 bula fractures. Compartment mid-shaft tibia fractures. problems: e.g. median nerve paraesthesia with distal syndrome: especially associated with closed low energy Intermediate \200 \200 stiffness: especially fractures around the elbow. Joint Malunion: may be compensated in younger children with remodeling. usually well tolerated if malunion is within plane of motion; Late \200 Overgrowth: hyperaemia). Femoral fractures in children may overgrow by 1 \200\2233cm. Defor mity: deformity several months later. Require long-term follow-up Non-union: occurs in long bones due to physeal stimulation (from if epiphysis is damaged, child may develop progressive rarely shaft of tibia/ulna. 20_McClure_20.indd 758 11/14/2012 3:24:06 PM orthopedic TRAUMA 759 Common fracture patterns The most common fracture pattern is a complete fracture of both co rtices (e.g. spiral, transverse, oblique, multifragmentary). However, the following fractur es are speci \201 c to children. \200 Buckle/torus outstretched hand (causing compression of one cortex resulting in \200\230buc kle \200\231 on the X-ray) resulting in a metaphyseal distal radius fracture. Inherently st able. Treatment immobilize in plaster of Paris/backslab; fracture clinic follow-up within 2 \200\2233 days. Remove plaster in 3 \200\2234wks and mobilize. Plastic but insuf \201 cie nt energy to produce a fracture. No fracture seen on X-ray (limb may appear \200\230bent \200\231). Commonly ulna (look out for radial head dislocation); occasionally \201 bula. Treat as for torus fracture. If severe bowing or dislocation require manipulation under ane sthetic. Greenstick fractures: like bending a young twig, the cortex will break on the tens ion side and bend on the compression side. The energy is insuf \201 cient to result in com plete bicortical fracture. It may require manipulation under anesthesia. Salter \200\223Har ris involve the physis (most commonly the distal radius). It is usually extra-articular, bu t fractures in the proximal femur/humerus, radial neck, distal \201 bula may be intra-art icular. fractures: children <10yrs. Usually caused by a fall on an deformation or bend fractures: traumatic bending/bowing of bone, fractures (physeal injuries): 20% of all children \200\231s fractures Some fractures may indicate NAI (b pp.527, 1000), e.g. spinal fracture or femoral shaft fra cture in the non-ambulant, rib fractures, two separate fractures at different stages of hea ling. These children should be referred for full investigation. 20_McClure_20.indd 759 11/14/2012 3:24:06 PM CHAPTER 20 Bones and joints 760 Osteochondroses A spectrum of conditions primarily affecting the epiphyses , but may also i nvolve cartilage and bone. Despite the term \200\230osteochondritis \200\231, the con- dit ion is not always due to in \202 ammation and may be due to trauma or over-usage, vascular irregularities, or may be a normal variation. The af- fected devascularized bony region un dergoes spontaneous healing with revascularization, resorption, and re-ossi \201 cation. S ymptoms are usually worse with activity and relieved with rest. It is usually a self-limiti ng con- dition with clinical outcomes ranging from normal to serious disability. Investigat ions include radiographs of the affected region, which may dem- onstrate fragmentation/coll apsed sclerotic bone. An MRI scan will con \201 rm the diagnosis. The conditions can be cl assi \201 ed anatomically. \200\230Physeal \200\231 (growth plate) osteochondroses Often require treatment. \200 Madelung deformity (distal radius): defect in the volar and ulna side of the distal radial physis resulting in a shortened tilted distal radius and a prominent ulna. Occurs in teenag e girls and features include pain, decreased range of movement, and abnormal wrist joint. T reated with analgesia and surgery. Scheuermann \200\231s Blount \200 disease (vertebra): see b p.744. disease: tibial physis. Articular osteochondroses Great potential for disability. \200 Freiberg in teenagers (females > males), presenting with pain on running and dancing. Joint tenderness with decreased range of movement, and pain on tip-toe standing. Managed with ch ange of activities, analgesia, orthotics, intra-articular corticosteroids+/ \200\223 surger y. Perthes \200\231 Panner \200\231s No history trauma. Mild \202 exion contracture diffu se synovitis. X-ray shows irregular areas with sclerosis. MRI/CT/USS may aid diagnosis. Tre atment NSAIDs, splint, occasionally arthroscopy. Prognosis good. Osteochondritis of capitel lum: occurs in older children. May be due to overloading of the elbow (e.g. overhand throwi ng/batting) with accentuation of any valgus deformity. Clinical \201 ndings include mecha nical block +/ \200\223 \202 exion contracture, general lateral elbow pain, and swelling. AP X-ray with elbow \202 exed 45 may demonstrate irregular joint surface. CT/MRI/USS h ave also been used. Treatment: rest with avoidance of exacerbating factors; anti-in \202 a mmatories; arthroscopic removal of loose bodies, drilling, or \201 xation of unstable les ions. Radial head: similar to osteochondritis capitellum, except the radial head is affecte d. Child is prone to developing overgrowth and joint incongruity. disease: infarction of the second metatarsal head or epiphysis \200 disease: see b p.750. disease (osteonecrosis of the capitellum): children <10yrs. 20_McClure_20.indd 760 11/14/2012 3:24:06 PM OSTEOCHONDROSES 761 Non-articular osteochondroses At tendon attachments \200 Osgood \200\223Schlatter \200 \231s of the tibia tubercle apophysis due to repetitive traction stress from the extensor m echanism in boys (aged 12 \200\22314yrs) > girls (aged 10 \200\22312yrs). Usually a self-li miting condition with complete resolution through physiological healing (physeal closure) o f tibia tubercle within 12 \200\22324mths. Presents with painful swelling over a prominent tibial tubercle (usually unilateral), associated with running/jumping. An irregular fragmen ted tibial tubercle may be seen on X-ray. Treatment includes non-operative (activity modi \201 cation, rest +/ \200\223 ice +/ \200\223 knee brace), physiotherapy (isometric hamstri ng and quadriceps exercises), medication (NSAIDs), and operative (occasionally excision of separate ossicles may improve symptoms after skeletal maturity). Sinding \200\223Larsen \200\223Johansson end of the patella. disease (tibial tubercle traction apophysitis): failure syndrome: related condition arising at distal At ligament attachments Adam \200\231s disease (medial epicondyle) Repetitive injury to the elbow following throwing/serving sports (e.g. rac- quet sports). Results in medial epicond ylar fragmentation or avulsion and delayed closure of the growth plate. May have ulnar nerv e involvement and point tenderness over the medial epicondyle. Treated with rest/change of activities, splintage, analgesia (NSAIDs). Gradual return to ac tivities once symptoms have settled. May need sur- gery to excise loose bodies. At impact sites \200 Kohler \200\231s midfoot pain and a limp in young children (males > females) especially wit h load-bearing sports. Treated with rest from load-bearing sport, in soles/casts. If sympto ms are severe, child may need to be non-weight- bearing with gradual return to activities d epending on symptoms. Sever \200\231s disease: calcaneal apophysitis. Caused by repeated mi crofracture (with subsequent in \202 ammation and healing) of the \201 brocartilaginous insertion of the tendo-Achilles to the calcaneum during the pubertal growth spurt. Symptoms vary depending on the level of activity and it improves with skeletal maturation. There ma y be a bony prominence at the tendon insertion due to overgrowth during healing response. T reatment symptomatic NSAIDs, heel cord stretching. disease: infarction of the navicular bone presenting as medial 20_McClure_20.indd 761 11/14/2012 3:24:06 PM CHAPTER 20 Bones and joints 762 Osteogenesis imperfecta See also b pp.763, 838. An inherited condition affecting collagen m atura- tion and organization. The incidence is around 1/20 000. Osteogenesis im- perfecta ( OI) is due to a mutation in type I collagen gene that predisposes to fracture formation. Fo llowing a fracture, initial bone healing is normal, but there is no subsequent remodeling a nd the bone heals with deformity. 10% are clinically asymptomatic. Clinical features \200 Bones: \200 \200 \200 Joints: Speci \201 c signs and X-ray features (see Table 20.2) . low birth weight/length for gestational age; short stature; 50% scoliosis. \200 ligamentous laxity resulting in hyperextensible joints. Investigations and diagnosis \200 \200 \200 \200 \200 Prenatal US scan may detect severe forms in fetus. Molecular genetic testing (pre- or postn atal). Biochemistry: Skin biopsy: Bone biopsy: diameters, increased cell numbers. normal/increased alkaline phosphatase (ALP). assess collagen in cultured \201 broblasts. histology \200\224increased Haversian canal + osteocyte lacunae Treatment No curative treatment. Aim to prevent and manage frac- tures with long-term rehab ilitation. Prevention Strategies to decrease fracture frequency include: \200 \200 \200 oral calcium supplements; bisphosphonates; synthetic calcitonin. Surgical interventions Intramedullary rods ( \201 xed length/telescoping) to prevent bowin g of long bones, especially for fractures in children >2yrs old. Corrective surgery for sco liosis deformities >50 . Prognosis In severe OI a good predictor of future walking is being able to sit by 10mths. M ay develop cardiopulmonary or neurological complications. Usually develop progressive short ening and deformity caused by multiple fractures, e.g. \200\230saber \200\231 tibia, \200 \230accordion \200\231 femora. 20_McClure_20.indd 762 11/14/2012 3:24:07 PM OSTEOGENESIS IMPERFECTA 763 Table 20.2 Osteogenesis imperfecta: Sillence classi \201 cation IU fractures Eyes (sclera) Bones X-ray features: thin cortices; osteopenia Type I Mild; AD (60 \200\22380%). Presenile hearing loss in 30 \200\22360%, often with aort ic valve regurgitation * No Blue Frequency of recurrent fractures decreases after puberty; diaphyseal > metaphyseal fracture s; usually ambulatory Wormian bones on SXR (occipital) Type II Perinatal. Lethal (stillborn/death within \201 rst year); AD Yes Relative macrocephaly, large fontanelles, micromelia, triangular facies with beaked nose, b owed limbs, legs abducted 90 Type III Progressive and deforming (most severe non-lethal t ype) AR Blue \200\230Beaded \200\231 ribs \200\224respiratory insuf \201 ciency Yes White Pectal deformity, triangular facies, relative macrocephaly, abnormal teeth, easy bruising, severe osteoporosis (fractures), progressive shortening, deformity \200\230Popcorn \200\231 metaphyses, \202 ared lower ribs, vertebral compression Type IV Moderately severe, AD. Usually able to attain community ambulation skills * Yes White Bowed long bones, relatively infrequent fractures (frequency decreases after puberty). Mode rately short stature Osteoporotic, metaphyseal \202 aring, vertebral compression Type V Moderately deforming; AD No White Mild/moderate; short stature IO calci \201 cation; hyperplastic calus Type VI Moderately/severely deforming No White Short stature, scoliosis \200\230Fish scale \200\231 bone lamellation Type VII Moderately deforming; AR No White Short stature; short proximal limbs IU, Intrauterine; AD, autosomal dominant; AR, autosomal recessive. * Type A, no teeth invol vement; type B, dentinogenesis imperfecta present. 20_McClure_20.indd 763 11/14/2012 3:24:07 PM CHAPTER 20 Bones and joints 764 Osteopetrosis Also known as marble bone disease or Albers \200\223Sch nberg disease. This is a rare chromosomal condition de \201 ned by failure of osteoclastic bone resorption and hence failure of remodeling. Classi \201 cation \200 type: AR. Severe skeletal deformity presenting at Malignant/infantile birth or shortly afte r. Poor prognosis. Bone marrow transplantation may help in some cases. Benign Prone to freq uent fractures. type: AD. Later childhood/adulthood benign presentation. Clinical features \200 Face: partial oculomotor nerve paralysis), compression of other cranial nerves resulting in deafness, facial nerve palsy. Teeth: mandible. generalized osteosclerosis, fragile bones ( due to failure to form Limbs: lamellated bone in stress areas) with fractures that are dif \201 cult to \201 x and prone to delayed union, dwar \201 sm. Hematological: pancytopen ia, spontaneous bleeding/bruises. Spleen (extra medullary haemopoiesis leading to hepatospl enomegaly). Kidneys: macrocephaly, hydrocephalus, \200\230abnormal eyes \200\231 (optic atrophy, late eruption; early caries, osteomyelitis, and necrosis of encroached marrow cavities leading to anemia, causes distal renal tubular acidosis (type 1 RTA). Investigations \200 Blood: primitive cells in blood \201 lm). Dry bone marrow tap. X-rays: normal trabecular pattern). Skull: Long femur). \200 pancytopenia and leucoerythroblastic picture (increased dense \200\230marble \200\231 bone (generalized increased density with loss of \200 underdeveloped mastoid air cells and paranasal sinuses. bones: widened ends ( \200\230Erlen meyer \202 ask \200\231 proximal humerus/distal phalanges \200\224 line, condensed bone proximal and distal ends of phalanges; metacarpals \200\224 \200\230 separated from central bone by area of normal calci \201 cation; vertebr al bones \200\224 \200\230 sclerotic upper and lower plates; bone normal elsewhere. dense transverse band in metaphysis close to epiphyseal bone within a bone \200\231 appearance \200\224sclerotic cortex sandwich/rugger jersey \200\231 appearance \200\224relative scan \200\224increased uptake in epiphyseal ends of long bones; Treatment Depends on severity of disease and is mainly supportive. Medical therapy includes glucocorticoids. Bone marrow transplant may help. Treatment of fractures is dif \201 cult due to dense bone quality. Prognosis Malignant type \200\224usually terminal within \201 rst 10yrs of life. Benign form \200\224lifespan unaffected. 20_McClure_20.indd 764 11/14/2012 3:24:07 PM CLEIDOCRANIAL DYSPLASIA 765 Cleidocranial dysplasia Also known as cleidocranial dysostosis. Characterized by de \201 c ient ossi- \201 cation of the clavicle (cleido) and bones of skull (cranial). It is a rar e congenital autosomal dominant condition. Clinical features \200 \200 General: Cranium: ossi \201 cation of sutures and fontanelles. Face: underdeveloped/de \201 cient facial bones leading to prominent forehead, pseudoexophthalmos, and hyperteloris m (due to small wide nasal bridge and widely spaced shallow orbits); protruding mandible. D ental: disordered eruption of secondary teeth (= extra/absent teeth). Ears: Upper limb: mob ile drooping shoulders; completely absent/partially absent clavicle (especially lateral par t, usually unilateral); recurrent dislocation shoulder/elbow; short middle and distal phala nges; long second metacarpal. Torso: Spine: prominent cervical transverse processes. limbs: tubular phalanges of feet. Lower proportionate mild short stature. No mental retardation. large skull, frontal and parietal bossing, delayed imperfect high arched/cleft palate, late loss of deciduous teeth with slow \200 hearing loss +/ \200\223 frequent ear infections. \200 narrow thorax and pelvis. delayed vertebral ossi \201 cation; scoliosis/lordosis; kyphosis ; Investigations \200 Skull: open anterior fontanelle; absent/delayed development of sinuses; hypoplastic maxilla . Clavicle: (commonest) or bipartite clavicle. Shoulder: Pelvis: coxa vara of hips. Spine: Renal tract: multiple imperfect ossi \201 cation centers (wormian bones); large total absence/partial absence of lateral aspect clavicle \200 subluxation of humeral heads. delayed ossi \201 cation pelvic bones with widened symphysis pubis; \200 failure of union of neural arches. Association with syringomelia association with Wilm \200 \231s tumor requires imaging kidneys. Treatment Usually abnormalities cause little functional disability. Lateral part of clav- i cle may cause brachial plexus problems (if so, for excision). Recurrent dislocations of the shoulder may require stabilization. Dental anomalies should be treated by maxillofacial su rgeons. Coxa vara may require valgus osteotomy. Prognosis Normal lifespan. 20_McClure_20.indd 765 11/14/2012 3:24:07 PM CHAPTER 20 Bones and joints 766 Skeletal dysplasias This is a heterogeneous group of conditions characterized by abnormal g rowth of bones. They can be classi \201 ed according to the region of bone involved or by their genotype (see Table 20.3). Radial dysplasia An absent or hypoplastic radius that causes abnormal radial deviation of t he hand. This is the most common form of longitudinal upper limb de \201 ciency and is oft en accompanied by a congenitally absent thumb. Anomalies of other systems may also be assoc iated. \200 \200 \200 \200 TAR. FA. Holt \200\223Oram syndrome: VACTERL (vertebral anomalies, anal atresia, cardiac ma lformations, tracheo-oesophageal \201 stula, renal and limb anomalies). AD; cardiac anomalies, and radial dysplasia. Management \200 \200 Serial castings/splinting. Surgery is usually required to place the hand in position to max imize function. If a thumb is absent, pollicization of the index \201 nger could improve function. The index \201 nger is reconstructed and radially positioned to form a function al \200\230thumb \200\231. 20_McClure_20.indd 766 11/14/2012 3:24:07 PM SKELETAL DYSPLASIAS 767 Table 20.3 Classi \201 cation of skeletal dysplasia Example of Region Hypoplasia ( \200\230failure of \200\231) Hyperplasia ( \200\230excess of \200\231) Epiphysis Articular cartilage Spondyloepiphyseal dysplasia Dysplasia epiphysealis hemimelica (Trevor \200\231s) Ossi \201 cation center Multiple epiphyseal dysplasia Physis Proliferating cartilage Achondroplasia Marfan \200\231s syndrome Hypertrophic cartilage Metaphyseal chondrodysplasia (Schmid, McKusick, Jansen) Enchondromatosis Type 2 collagen Diastrophic dysplasia Proteoglycan metabolism Kneist syndrome Metaphysis Intramembranous bones Cleidocranial dysostosis Formation of primary spongiosa Hypophosphatasia Absorption of primary spongiosa Osteopetrosis (functionally de \201 cient osteoclasts) Diaphysis Diaphyseal aclasia Multiple exostoses fracture Periosteal bone formation Engelmann \200\231s disease Endosteal bone formation Hyperphosphataemia (vitamin D resistant rickets) 20_McClure_20.indd 767 11/14/2012 3:24:07 PM CHAPTER 20 Bones and joints 768 Juvenile idiopathic arthritis JIA is a common chronic childhood disorder (UK prevalence 1/1 000; inci- dence: 1/10 000). It is a diagnosis of exclusion in children <16yrs old with a h istory of at least 6wks of persistent arthritis. JIA is divided into 7 subsets for research purposes.1 These are not diagnostic categories, but are useful clinical groups. As a child \200\231s symptoms evolve with time (e.g. the appear- ance of a psoriatic rash), they may change subtype. Classi \201 cation of JIA1 \200 \200 relative frequency,10 \200\22313%. See b p.772. Systemic arthritis: Oligoarthritis (persistent or extended): p.773. Polyarthritis (rheumato id factor +ve): p.774. Polyarthritis (rheumatoid factor \200\223ve): p.776. Psoriatic arth ritis: Enthesitis-related arthritis: Undifferentiated arthritis: relative frequency, 40%. See b relative frequency, 3%. See b relative frequency, 27%. See b \200 \200 relative frequency, 2 \200\22315%. See b p.777. relative frequency, 1 \200\2237%. See b p.778. relative frequency, 2 \200\22315%. Differential diagnoses of childhood arthritis \200 Infection: \200\224septic arthritis; osteomyelitis (b pp.738 \200\223741); bacterial \200 \200 \200\224rubella; parvovirus B19; infectious mononucleosis (b p.711); viral \200 Lyme, Post-infection: \200 \200 \200 Malignancy: \200 \200 p \200 \200 Orthop edic: \200 \200 \200 \200 \200 \200 Hypermobility: \200 \200 \200 Brucella, TB (b pp.702, 712, 722). reactive arthritis; post-streptococcal reactive arthritis; rheumatic fever ( b p.244). b p.656); leukemia ( neuroblastoma ( b p.666); bone tumors \200\224benign or malignant; metastatic disease. b p.750); Perthes and other osteochondritides ( slipped upper femoral epiphysis ( hip dysplasia ( inf antile coxa vara; chondromalacia patellae ( irritable hip ( b p.752); b p.748); b p.754); b pp.734 \200\223737). benign hypermobility Marfans, Ehlers \200\223Danlos ( IBD ( \200\224local or generalized; b pp.838, 940); b p.332). 20_McClure_20.indd 768 11/14/2012 3:24:07 PM JUVENILE IDIOPATHIC ARTHRITIS 769 Connective tissue disease: b p.780); \200 SLE ( \200 juvenile dermatomyositis ( \200 systemic sclerosis Metabolic disorders: \200 \200 Hematological: \200 \200 \200 V asculitis: \200 HSP ( \200 polyarteritis/microscopic polyangitis b p.716); \200 Kawas aki disease ( b p.791). \200 Takayasu arteritis ( Immunode \201 ciency syndromes. Other in \202 ammatory disorders: \200 \200 \200 Idiopathic pain syndromes: \200 \200 \200 b p.782); \200\224limited or progressive (b p.786). gout; mucopolysaccharidoses ( b p.986). b p.620); SCD ( other haemoglobinopathies ( hemophilia ( b p.622); b p.636). b p.788); \200 sarcoid; chronic recurrent multifocal osteomyelitis ( SAPHO (synovitis, acne, pustulosis, h yperostosis, and osteitis). b p.740); chronic regional pain syndromes; \201 bromyalgia \200\230non-organic pain \200\231 \200\224a cry for help (b pp.310, 592). Reference 1 Petty RE, Southwood TR, Manners P, et al. (2004). International League of Assoc iations for Rheumatology classi \201 cation of juvenile idiopathic arthritis: second revis ion, Edmonton 2001. J Rheumatol 31: 390 \200\2232. 20_McClure_20.indd 769 11/14/2012 3:24:08 PM CHAPTER 20 Bones and joints 770 Juvenile idiopathic arthritis: clinical principles and management Before labeling child wit h diagnosis of JIA it is imperative to exclude the differential diagnoses, the most importa nt of which are sepsis, malignancy, and trauma (see b p.736). History from carer and child \200 \200 Limp, stiffness and loss of function, pain, or malaise. Onset usually gradual. Beware of mi sleading history of trauma as young children frequently fall without signi \201 cant injur y. History of non-use, or change in use. Child may not complain of pain. Infant may be \200\230irritable \200\231. In \202 ammatory symptoms: Stiffness is rarely volunteered. Pa rents sometimes describe child as \200\230like a little old person in the mornings \200 \231. Toddler \200\231s behavior may be perceived as being dif \201 cult and uncooperative (e.g. refusing to move in the morning, then running in the afternoon). History of associat ed rash, fever, weight loss. History of sore throat, URTI, antecedent infections, and trave l. Family history of arthritis, psoriasis, colitis, rheumatic fever, or acute iritis. \200 \200 \200 worse after rest or inactivity. \200 \200 Examination \200 \200 \200 Observe the child before they become self-conscious. Watch them playing and walking. Examin e all the joints and spine for swelling, warmth, pain on movement, or limited movement. Mea sure for leg length inequality and pelvic tilt. Examine muscle bulk around affected joints. Assess general muscle strength. Examine the skin, hair and nails for rashes, psoriasis. Ge neral examination: Examine mouth and palate for ulcers, dentition; fauces for asymptomatic tonsillitis; heart for murmurs; abdomen for hepatosplenomegaly. \200 \200 \200 \200 \200 vital signs, height, weight, and BP. Investigations \200 \200 \200 \200 FBC may show mild anemia and thrombocytosis. Neutrophilia suggests sepsis or systemic JIA. Severe anemia or thrombocytopenia: ESR/CRP usually normal or mildly elevated. Very high lev els suggest infection or malignancy. High ESR plus thrombocytopenia suggests leukemia. Infe ction screen: (CMV, EBV, parvovirus B19, hepatitis) and culture. Rheumatoid factor: joints) . Exclusion criterion for oligoarticular JIA. consider leukemia. throat swab, urinalysis, blood for ASOT, viral serology non-speci \201 c test, but signi \201 cant in polyarthritis (>5 20_McClure_20.indd 770 11/14/2012 3:24:08 PM JUVENILE IDIOPATHIC ARTHRITIS 771 ANA: prognostic determinant for iritis. Muscle enzymes (CK, LDH, aldolase) raised in dermat omyositis, but can be normal. Very high LDH suggests malignancy. Imaging: \200 non-speci \201 c (5% children ANA +ve). In oligoarticular JIA limited radiographs swelling, and juxta-articular osteopenia; later \200\224joint space narrowing a nd erosions; \200 \200\224helpful for con \201 rming synovitis and joint effusion; US M RI \200 \200\224useful for atypical monoarthritis; gadolinium-enhanced MRI is gold stand ard for diagnosis of synovitis, but does not differentiate from sepsis. \200\224exclude fracture or tumor; early JIA \200\224soft tissue Synovial \202 uid aspirate: culture for sepsis. Microscopy rarely helpful. Management General \200 \200 \200 Establish diagnosis and counsel child and parents. Start treatment as soon as possible. Mos t children will need regular hospital review to look for presence or reappearance of thicke ned synovium or effusions. Exercise: Psychological support for children and carers: groups (e.g. Arthritis Research Campaign). Ask about school performance and support at school. Ado lescents may need counseling about contraception and alcohol if taking MTX. Amyloidosis: \200 regular, daily aerobic and \200\230range of motion \200\231 exercises. education and support \200 rare complication of severe disease. Joints \200 Minimize pain and stiffness using NSAIDs: \200 \200 \200 \200 Prevent deformity: re gular daily exercises; night splints; intra-articular steroid injections (triamcinolone) ma y settle in \202 ammation for years. Control disease activity: Etanercept: NSAIDs and SC M TX. ibuprofen (30 \200\22340mg/kg); diclofenac (1.5 \200\2232.5mg/kg bd); naproxen (5 \200\2231 5mg/kg bd); piroxicam (5 \200\22320mg daily according to weight). \200 MTX oral or SC in resistant cases. anti- tumor necrosis factor (TNF) if unresponsive to Eye screen for uveitis Must have regular screening, initially 3-monthly, by experienced oph thal- mologist. Treat with topical steroids and midriatics. Course is independent of joint disease severity. Potentially blinding. Growth Measure growth velocity; nutritional status; muscular atrophy. Dentition Watch for caries. Once the diagnosis is established the child should be looked after by a pediatric rheumatol ogist for specialist drugs and co-ordinating multi- disciplinary support. 20_McClure_20.indd 771 11/14/2012 3:24:08 PM CHAPTER 20 Bones and joints 772 Systemic arthritis Multisystem disease is often diagnosed late as joint involvement is ofte n late. Peak age 2 \200\2233yrs; 10 \200\22320% JIA; equal male:female. Clinical features \200 C, returning to normal Fever is essential, typically quotidian up to 39 between attacks. Rash: Present when warm a nd disappears within minutes. Myalgia, arthralgia, and arthritis. Arthritis often appears a fter \201 rst 6mths of illness and can be oligo- or polyarthritis. Generalized lymphadeno pathy and hepatosplenomegaly. Polyserositis with pericarditis, pleuritis, and sterile perit onitis. Silent pericardial effusions (15%). Myocarditis + tachycardia, cardiomegaly, and co ngestive cardiac failure is rare. Growth retardation amyloidosis (dif \201 cult to treat). Late complications: MAS: rare, life-threatening; precipitated by infection or NSAIDs. Haem ophagocytic bone marrow with falling WBC, platelets, and ESR, and very high ferritin. salmon pink, macular/urticarial on chest, trunk, and intertrigones. \200 \200 \200 s to disease, steroids, or joint damage. Investigations \200 FBC (normocytic or hypochromic anemia; leucocytosis; thrombocytosis). ESR/CRP can be high: Hypoalbuminaemia: catabolism, possibly proteinuria secondary to renal amyloid. ANA and RF u sually \200\223ve. Viral titres and blood cultures. Malignancy screen: ECG and echocardiog ram. \200 use to monitor disease during treatment. multifactorial \200\224poor diet, general ill health with \200 \200 \200 CXR, US abdomen. Management \200 NSAIDs for initial management of pain, fever, and serositis. Indomethacin often used for pe ricarditis. Pulsed IV corticosteroids if no improvement after 1wk of NSAIDs. Oral steroids at 1mg/kg in divided doses until fever settled and in \202 ammatory markers normal. Taper dose to reduce side-effects. Use alternate day doses and add steroid-sparing agent. MTX is used, but is not as effective as in other JIA subsets. Intra-articular corticosteroid for \202 ares of single joints. Biological therapy: \200 \200 \200 anti-TNF and anti-IL6 in resistant cases. Prognosis Three groups \200\224monocyclic (11%); recurrent or polycyclic (34%); and per- si stent (55%). Monocyclic patients do well. More than 33% of the others will have permanent d isability with active disease in adult life. Death from infection, MAS, or amylodosis. 20_McClure_20.indd 772 11/14/2012 3:24:08 PM OLIGOARTICULAR JUVENILE IDIOPATHIC ARTHRITIS 773 Oligoarticular juvenile idiopathic arthritis \200 Commonest subtype (previously known as pauciarticular JCA/JRA). 40% of patients. Two subset s are recognized: joints increases to more than 4 within the \201 rst 6mths of illness, i t is termed extended oligoarticular JIA. Children may develop silent, blinding iritis (ante rior uvertis). It is usually ANA-positive patients (40 \200\22375% of this form of illness) who are at risk of developing iritis. persistent and extended. If the number of Clinical features \200 \200 \200 \200 Diagnosis of exclusion; rule out infection. Milder symptoms than reactive arthritis; no con stitutional symptoms. Often present with joint swelling or limping rather than pain. 2/3 si ngle joint; 1/3 only 2 joints; often asymmetrical; knees, ankles, elbows, wrists common, bu t any joint possible. Careful examination may reveal more extensive disease as the child ma y be too young to express pain. Elbows and knees may lack full extension, but not be painfu l. Affected leg may overgrow; measure leg lengths and check pelvis is level. Observe gait f or circumduction to compensate for limb overgrowth. \200 Investigations \200 \200 FBC; CRP (usually normal); ANA (prognostic value for uveitis). X-ray: exclude fracture, tumor; look for overgrowth and damage. Management \200 \200 Regular review to assess joints, eyes, and general growth. NSAIDs for pain and stiffness: n aproxen, or piroxicam). Intra-articular steroid injections: If not controlled with oral NSA IDs and intra-articular steroids, MTX oral or SC is used in resistant cases. Rarely etanerc ept (anti-TNF therapy) is needed. Screen for uveitis: full dose for 8wks (ibuprofen, diclofenac, \200 may settle in \202 ammation for years. \200 initially 3-monthly, by ophthalmologist. Disease course and prognosis \200 \200 80% normal at 15yrs. \200\230Extended \200\231 subset have worse prognosis Uveitis is m ost important extra-articular complication 20_McClure_20.indd 773 11/14/2012 3:24:08 PM CHAPTER 20 Bones and joints 774 Rheumatoid factor-positive polyarthritis A chronic symmetrical in \202 ammatory polyarthri tis (>5 joints) with positive RF on two occasions at least 3mths apart. Typically affects t eenage girls, though any age possible. Similar to adult rheumatoid arthritis, but gener- al ly a more aggressive disease. ARA criteria for diagnosis of rheumatoid arthritis1 \200 \200 \200 \200 \200 \200 \200 Morning stiffness: Arthritis in at least 3 joints: Hand arthritis: Symmetrical arthritis Rh eumatoid nodules Rheumatoid factor-positive Erosions on X-ray >1hr at peak illness witnessed by a physician wrists, MCPs, or PIPs All symptoms need to be present for at least 6wks. Four or more crite- ria need to be ful \201 lled for diagnosis of rheumatoid arthritis (RA). These are primarily classi \201 cati on criteria (90% sensitivity and speci \201 city). Clinical features \200 \200 History of early morning and immobility stiffness. Symmetrical arthritis affecting large an d small joints associated with rheumatoid nodules. Wrists and PIPs affected early. Hip invo lvement can be aggressive and lead to early hip replacement. Tenosynovitis common around \201 ngers and ankles. Systemic features: hepatosplenomegaly; lymphadenopathy; serositis (p ericarditis and pleurisy). Eyes: lead to a painful red eye. \200 low grade fever (differential diagnosis systemic JIA); uveitis rare; dry eyes relatively common (10 \200\22335%); episcleritis can Investigations \200 \200 \200 FBC; CRP; LFTs; RF; ANA. Renal function and urinalysis. X-rays of affected joints and CXR. Management \200 \200 Monitor disease activity and aim for good control of arthritis. Regular meticulous assessme nt for tender and swollen joints, muscle wasting, joint damage, and loss of joint function. Monitor growth development and nutritional status. Exercise: Psychosocial development can be severely affected and needs addressing. \200 \200 range of joint motion and aerobic activity. 20_McClure_20.indd 774 11/14/2012 3:24:08 PM RHEUMATOID FACTOR-POSITIVE POLYARTHRITIS 775 Treatment \200 \200 \200 Start treatment as soon as possible. NSAIDs provide relief from pain, stiffness, and swelli ng. All children will need disease-modifying antirheumatic drug (DMARDs): MTX is the least toxic and most well established \200\224orally or SC. Others include hydroxychloroquine, su lfasalazine, azathioprine, ciclosporin, and gold. These have been used in combination with MTX or alone. Steroids: intra-articular steroids to settle synovitis in individual joints; oral steroids as adjunct to DMARDs; pulsed IV steroids for \202 are of disease. Aim to mi nimize total steroid load. Biologic agents: have been shown to reduce joint erosions and ma y prevent progression to secondary arthritis Anti-TNF agents (etenercept, in \202 iximab, adalimimab) Prognosis Most children survive into adulthood though with poor func- tional outcome becaus e of aggressive, unremitting disease, early erosions, and high incidence of joint replaceme nt. The use of aggressive, early sys- temic MTX and biological therapies may have improved this outcome. Reference 1 Arnett FC, Edworthy SM, Bloch DA, et al. (1988). The American Rheumatism Associ ation 1987 revised criteria for the classi \201 cation of rheumatoid arthritis. Arthritis Rheum 31(3) : 315 \200\22324. 20_McClure_20.indd 775 11/14/2012 3:24:08 PM CHAPTER 20 Bones and joints 776 Rheumatoid factor-negative polyarthritis 30% of JIA cases. Previously known as polyarticula r onset JCA. Characterized by 5 or more affected joints within \201 rst 6mths. Clinical features \200 \200 