Peggers Super Summaries: Paediatric Hip

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1 EMBRYOLOGY Development o Mesenchymal stem cells cartilage blood supply bone Dates o 6/40 Limb development o 8-11/40 hip development (acetabulum and hip formed from one bone splitting by apoptosis) o 16/40 - capsule and hip muscles DDH o 1 in 1000 o Genetic and environmental factors o 20% bilateral o Females > males Risk factors o Breach o First born o FH o Oligohydramnios o Syndromic o Associated feet problems Examination o General syndrome or neuromuscular disorders o Specific leg length, skin creases, club foot Barlow dislocation test flex and adduct Ortalani abduction relocates hip o Investigations <4.5 US >4.5 x ray Screening worth while o Myers ,000 NZ babies screened successfully Danger of US overtreatment Availability Cost o Clegg 1999 JBJS financial justification of DDH screening o Ganz JBJS 1995 consequences of DDH Premature OA if the following are present

2 CEA <16 0 Acetabular index >15 0 >30% of head uncovered o Wainwright JBJS 33 yr f/u in 147 patients 15% had AVN at 5 years post op 36% valgus angulation 15% needed THR at mean 36 years Investigations o Xrays Acetabular angle N Increase in medial gap Disrupted shentons line CEA > 25 0 o US if less than 4.5 years o Arthrogram to confirm congruency o MRI to confirm hip placement after hip spica Classification o Graf USS in coronal plane of hip 1 normal Angle > < 3 months immature immature > 3 months shallow acetabulum likely to persist 3 Subluxed angle < Dislocation with interposition of labrum o Severn 1- normal 2- short neck 3- Dysplastic roof 4- mild subluxation 5- head in 2 nd acetabulum 6- dislocated Algorithm o <6/12 Pavlik harness or closed reduction to reduce then spica 5% failure rate of harness if started <3/12 Birth splinting 95% success Splinting 6-8 weeks 90% success 3-6 months 50% success o >6/12 reduce closed and if subluxed using die then open reduction Soft tissue release

3 o >3years open reduction Soft tissue tenotomy +/- osteotomy Failed closed reduction consider delay in treatment until head as ossified to reduce risk of AVN AGE OF REDUCITON < 1 year at diagnosis 12% risk of OA > 3 years at diagnosis 60% OA risk OPEN REDUCTION TECHNIQUES Medial approach increases AVN Anterior approach between rectus femoris and TFL AVN ASSESSMENT MacEwan 1980 o 1 normal epiphysis o 2 lateral growth plate injury = valgus deformity of neck o 3 medial growth plate = varus neck deformity o 4 damage to both growth plate and epiphysis PERTHES o Idiopathic AVN of femoral head o M:F 4:1 o 10% B/L Causes o Vascular o Trauma o Effusion o Endocrine or metabolic Pathogenesis o <412 blood from metaphysis o 4-7 years old lateral epiphyseal supply (at risk from effusion) o > 7 years blood supply from epiphysis and ligamentum teres RF o FH o Low birth weight Pathology o Synovitis o Fragmentation o Reossification o Healing and remodelling

4 o Containment to maintain sphericity o Maintain rom a o psychology Outcomes o Herring JBJS 2004 <8 years of age do better >8years and groups B & C surgery better o Wiig JBJS 2008 >6 years old & >50% of femoral head femoral varus osteotomy gave better outcomes vs PT or Orthotics SUFE o 1-10 in 100,000 o Slip through 4rapeziecto weakest region o Obesity and afro 4rapeziec are RF Goals o Restore functions o Prevent complications Imaging o Sail sign o Kleins line o Southwicks o Epiphysis opening o Shentons line broken o Epiphyseal / head angle Classification o Clinically Risk of AVN by Loder et al Unable to weight bear AVN risk 47% Able to weight bear <10% risk o Degree of slip Southwick < >60 0 o Reduce or not o Open or not o Dunn osteotomy vs Ganz open

5 o Prophylactic pinning of other side o Stable or chronic 1 screw o Unstable 2 screws amd anterior decompression of capsule o +/- open surgical correction SICKEL CELL o Autosomal recessive gene causing RBC haemolysis Dx o Electrophoresis o Thin film Clinically o Asplenic increase risk of infection salmonella osteomyelitis o Anaemic o Risk of infarctions o Medically o Surgical Need O2, transfusions pre op, tourniquet and contrast media avoidance PROXIMAL FOCAL FEMORAL DEFICIENCY o Congenital syndrome with poor hip joint development and femoral shortening Classifications o Aitken A head shaft connected B No head shaft connection C absent head dysplastic acetabulum D short femur no acetabulum o MDT o Function o Cosmesis o NICE guidelines <20cm shortening go for lengthening >20cm shortening go for prosthesis