Orthopaedics Flashcards
DDH, limp, osteomyelitis, septic arthritis, transient synovitis, rickets, JIA, Perthe's disease, reactive arthritis
Bow legs + knock knees
Bow legs (genu varum): knees wide, common when first walk normal up to 3y but may be path in rickets or Blount disease
Knock knees (genu valgum): feet wide knees close, common in young + usually goes spontaneously
Flat feet (pes planus)
Usually disappears
May persist in hypermobility, contractures or JIA
In-toeing
Common, child can fall, normally self-limiting
Metatarsus varus: adduction deformity, passively correctable
Medial tibial torsion: tibia LR less than normal, self corrects by 5y
Persistent ante version of femoral neck: femoral neck twisted more than normal at hip, usually goes by 8y, may be a/w hypermobility
Toe walking
Common in young children, may persist with habit or DMD/tight achilles tendon/cerebral palsy/inflammatory arhtritis
Developmental dysplasia of the hip
A spectrum from dysplasia - subluxation - frank dislocation
RF: breech, female (6x), FH, first born, oligohydramnios, macrosomic bw, congenital calcaneovalgus foot deformity
Screened for in NIPE, at 8w check, hip US to confirm. Do hip US on infants who have RF for it (not XR as hip not calcified) as the screening signs can be missed
Later presentation: limp, abnormal gait, asymmetrical skin folds around hip, limited abduction, shortening of affected leg
M: if just unstable most stabilise by 6w, Pavlik harness in up to 4-5 months old (keeps hip flexed + abducted, for up to 6m), surgery if fails/identified late
Comp: necrosis of femoral head
Causes of limp in young child (1-3y)
- Acute: SA, OM, transient synovitis, trauma, malignancy (neuroblastoma, leukaemia)
- Chronic: DDH, talipes, cerebral palsy, JIA
Causes of limp in older child (3-10y)
- Acute: transient synovitis, SA, OM, trauma/overuse, Perthes disease, JIA, leukaemia, complex regional pain syndrome
- Chronic: Perthes, DMD, JIA, tarsal coalition
Causes of limp in adolescents
- Acute: trauma/overuse, SUFE, AVN of FH, reactive arthritis, JIA, SA/OM, osteochondritis dissecans (knee), bone tumours, complex regional pain syndrome
- Chronic: chronic SUFE, JIA, tarsal coalition
Osteomyelitis
This is infection of the metaphysis of long bones (often distal femur/proximal tibia); 15% also have SA
Path: haematogenous spread (or direct spread from wound), S aureus commonest, Strep, H influenza if not immunised; in SCD also at risk of salmonella (but Staph is still commonest)
CF: markedly painful immobile limb + acute febrile illness, may have a sterile effusion of an adjacent joint, back/groin pain if vertebral/pelvic bones, infants may be more insidious
Ix: BC+, WCC + CRP raised, XR may be initially normal, US-periosteal elevation, MRI-subperiosteal pus + purulent debris in bone
M: IV Abx for weeks until clinically recovered, then oral Abx for several weeks; may need surgical decompression/drainage
Comps: necrosis, chronic infection (discharging sinus, deformity)
Rickets causes
Failure of mineralisation in growing bone/osteoid tissue
- nutritional (primary): insufficient exposure to direct sun, dark skin means less absorption, maternal vitamin D def, diets low in calcium/phosohorous/vit D (e.g. prolonged ebf, vegans)
- intestinal malabsorption e.g. coeliac, pancreatic insufficiency in CF, high phytic acids in diet e.g. chapattis
- defective 25-hydroxyvitamin D production in chronic liver disease
- increased 25-hydroxyvitamin D metabolism via enzyme induction from AEDs
- defective production of 1,25-dihydroxyvitamin D in CKD, Fanconi syndrome
Rickets CF
Craniotabes-press over occipital/parietal bones feels like pressing a ping pong ball Rachitic rosary - palpable costochondral junctions Widened wrists/ankles esp in crawling infants Harrisons sulcus cos ribs softened Bow legs Misery Poor growth Delayed closure of anterior fontanelle Hypotonia Seizures Cardiomyopathy Flattened skull Dental disease
Bloods: low/normal calcium, low phosphate, high ALP, low/normal 25-hydroxyvitamin D, high PTH
XR wrist: cupping + fraying of metaphases, widened epiphyseal plate
Rickets management
Nutrition - balanced diet with oily fish/egg yolk/milk/cereals/fruit juice; plus supplements vit D3 (cholecalciferol)
Correct RF
Healing 2-4w
Septic arthritis
Joint space infection can cause joint destruction, haematogenous or from OM spreading/puncture wound/skin lesions
Usually affects one joint-mostly hip in young children
Most commonly due to S aureus (used to be Hib but now vaccine), consider immunodeficiency or sickle cell
CF: red warm tender joint, reduced ROM, acutely unwell febrile child, infants often hold limb still (hardest to diagnose in them cos more SC fat), joint effusion in neighbouring joints, may have referred pain to knee
Ix: high WCC + CRP, take BC, US-effusion, XR-exclude trauma (SA initially normal but may have widened joint space/ST swelling), MRI/isotope scan if site of infection unclear; definitive = aspiration of joint space under US (For culture; ideally do immediately)
M: IV Abx then prolonged oral course, wash out/drainage if deep e.g. hip or unresponsive, immobilisation initially then mobilise to prevent deformity
Causes of a swollen joint
- Infection - SA, OM
- Inflammation - JIA, reactive arthritis, HSP, IBD, serum sickness (type 3 hypersensitivity reaction from an injection, usually also rash)
- Acute joint bleed - haemophilia
- Malignancy - leukaemia, neuroblastoma
- Trauma
Transient synovitis
Commonest cause of acute hip pain in 2-12y, often follows/accompanies a viral infection
Diagnosis of exclusion - usually still do BC + aspiration
CF: sudden onset pain in hip/limp, no rest pain, reduced ROM, may be referred to knee, afebrile/mild fever + not unwell
M: bed rest, usually improves in a few days
Juvenile idiopathic arthritis
Persistent joint swelling >6w in absence of infection or any other cause
Majority distinct from RA, at least 7 subtypes (based on which joints initially affected, HLA type + extra CF)
CF: gelling, morning joint stiffness, pain, younger kids may be intermittent limp/deterioration of behaviour/activities rather than pain complaints, usually develop swelling from fluid/inflam/synovial proliferation/peri-articular swelling
Ix: often initially clear, anti-nuclear factor may be + (but can be + in unaffected!)
Differential: widespread joint pain + fatigue consider a CT disorder
Comps: chronic anterior uveitis (can result in glaucoma/cataracts), flexion joint contractures, growth failure (generalised from steroids/anorexia, or localised like leg length discrepancy), constitutional e.g. anaemia of chronic disease, osteoporosis
M: induce remission ASAP, NSAIDs for analgesia, steroid joint injections (v good if oligoarticular, usually sedation/Entonox), methotrexate (weekly tablet/injection, good for poly arthritis, need regular bloods, nausea common), systemic steroids (avoid as much as poss), cytokine modulators (when refractory to methotrexate, strict guidance as spenny)
