133发育性髋关节脱位英文.pptx

Developmental Dysplasia of the HipHeather RocheApril 4,2002Previously known as congenital dislocation of the hip implying a condition that existed at birthdevelopmental encompasses embryonic,fetal and infantile periodsincludes congenital dislocation and developmental hip problems including subluxation,dislocation and dysplasiaNormal Growth and Development Embryologically the acetabulum,femoral head develop from the same primitive mesenchymal cellscleft develops in precartilaginous cells at 7th week and this defines both structures11wk hip joint fully formedacetabular growth continues throughout intrauterine life with development of labrumbirth femoral head deeply seated in acetabulum by surface tension of synovial fluid and very difficult to dislocatein DDH this shape and tension is abnormal in addition to capsular laxityThe cartilage complex is 3D with triradiate medially and cup-shaped laterallyinterposed between ilium above and ischium below and pubis anteriorlyacetabular cartilage forms outer 2/3 cavity and the non-articular medial wall form by triradiate cartilage which is the common physis of these three bonesfibrocartilaginous labrum forms at margin of acetabular cartilage and joint capsule inserts just above its rimarticular cartilage covers portion articulating with femoral head opposite side is a growth plate with degenerating cells facing towards the pelvic bone it opposestriradiate cartilage is triphalanged with each side of each limb having a growth plate which allows interstitial growth within the cartilage causing expansion of hip joint diameter during growthIn the infant the greater trochanter,proximal femur and intertrochanteric portion is cartilage4-7 months proximal ossification center appears which enlarges along cartilaginous anlage until adult life when only thin layer of articular cartilage persistsDevelopment cpntExperimental studies in humans with unreduced hips suggest the main stimulus for concave shape of the acetabulum is presence of spherical headfor normal depth of acetabulum to increase several factors play a rolespherical femoral headnormal appositional growth within cartilageperiosteal new bone formation in adjacent pelvic bonesdevelopment of three secondary ossification centersnormal growth and development occur through balanced growth of proximal femur,acetabulum and triradiate cartilages and the adjacent bonesDDHTight fit between head and acetabulum is absent and head can glide in and out of acetabulumhypertrophied ridge of acetabular cartilage in superior,posterior and inferior aspects of acetabulum called“neolimbus”often a trough or grove in this cartilage due to pressure from femoral head or neck98%DDH that occur around or at birth have these changes and are reversible in the newborn2%newborns with teratologic or antenatal dislocations and no syndrome have these changesDevelopment in treated DDH different from normal hipgoal is to reduce the femoral head asap to provide the stimulus for acetabular developmentif concentric reduction is maintained potential for recovery and resumption of normal growthage at which DDH hip can still return to normal is controversial depends onage at reductiongrowth potential of acetabulum damage to acetabulum from head or during reductionaccessory centers seen in 2-3%normal hips however in treated DDH seen up to 60%appearing ages 6 months to 10 years(should look for these on radiographs to indicate continued growth)Epidemiology1 in 100 newborns examined have evidence of instability (positive Barlow or Ortolani)1 in 1000 live births true dislocationmost detectable at birth in nurseryBarlow stated that 60%stabilize in 1st week and 88%stabilize in first 2 months without treatment remaining 12%true dislocations and persist without treatmentColeman26%become dislocated,13%partial contact 39%located but dysplatic features 22%normalEtiologyGenetic and ethnicincreased native Americans but very low in southern Chinese and Africanspositive family history 12-33%10 x risk if affected parent,7X if siblingintrauterine factorsbreech position(normal popn 2-4%,DDH 17-23%)oligohydroamniosneuromuscular conditions like myelomeningocelehigh association with intrauterine molding abnormalities including metatarsus adductus and torticollis first bornfemale baby(80%cases)left hip more commonDiagnosisClinical risk factorsPhysical examOrtolani Testhip flexion and abduction,trochanter elevated and femoral head glides into acetabulumBarlow Testprovocative test where hip flexed and adducted and head palpated to exit the acetabulum partially or completely over a rimsome base there treatment on whether ortolani+versus Barlow+feeling Barlow+more stableLovell and Winter make no distinction2%extreme complete irreducible teratologic disloactions assoc with other conditions like arthrogyposisLate DiagnosisSecondary adaptive changes occurlimitation of abduction due to adductor longus shorteningGalleazi signflex both hips and one side shows apparent femoral shorteningasymmetry gluteal,thigh or labial foldslimb-length inequailtywaddling gait and hyperlordosis in bilateral casesRadiographyUltra soundmorphologic assessment and dynamicanatomical characteristicsalpha angle:slope of superior aspect bony acetabulumbeta angle:cartilaginous component(problems with inter and intraobserver error)dynamic observe what occurs with Barlow and ortolani testingindications controversial due to high levels of overdiagnosis and not currently recommended as a routine screening tool other than in high risk patientsbest indication is to assess treatment guided reduction of dislocated hip or check reduction and stability during Pavlik harness treatmentRadiography contnewborn period DDH not a radiographic diagnosis and should be made by clinical examafter newborn period diagnosis should be confirmed by xrayseveral measurementstreatment decisions should be based on changes in measurementsRadiological Diagnosisclassic featuresincreased acetabular index(n=27,30-35 dysplasia)disruption shenton line(after age 3-4 should be intact on all views)absent tear drop signdelayed appearance ossific nucleus and decreased femoral head coveragefailure medial metaphyseal beak of proximal femur,secondary ossification center to be located in lower inner quadrantcenter-edge angle useful after age 5 (20)when can see ossific nucleus PeNatural Historyin NewbornsBarlow1 in 60 infants have instability(positive Barlow)60%stabilize in 1st week88%stabilize in 2 months without treatment12%become true dislocations and persistColeman23 hips 3 months26%became dislocated13%partial contact with acetabulum39%located but dysplastic feature22%normalbecause not possible to predict outcome all infants with instability should be treatedAdultsVariabledepends on 2 factorswell developed false acetabulum(24%chance good result vs 52%if absent)bilateralityin absence of false acetabulum patients maintain good ROM with little disabilityfemoral head covered with thick elongated capsule false acetabulum increases chances degenerative joint diseasehyperlordosis of lumbar spine assoc with back painunilateral dislocation has problemsleg length inequality,knee deformity,scoliosis and gait disturbanceDysplasia and SubluxationDysplasia(anatomic and radiographic defn)inadequate dev of acetabulum,femoral head or bothall subluxated hips are anatomically dysplasticradiologically difference between subluxated and dysplastic hip is disruption of Shentons linesubluxation:line disrupted,head is superiorly,superolaterally ar laterally displaced from the medial walldysplasia:line is intactimportant because natural history is differentNatural History ContSubluxation predictably leads to degenerative joint disease and clinical disabilitymean age symptom onset 36.6 in females and 54 in mensevere xray changes 46 in female and 69 in males Cooperman32 hips with CE angle 6 months success 2-3-weeks)subgroup where failure may be predictable Viere et al absent Ortolani signbilateral dislocations treatment commenced after age 7 weekTreatment closed reduction and Spica CastingFemoral Nerve Compression 2 to hyperflexionInferior Dislocation Skin breakdownAvascular Necrosis6 months to 2 years ageClosed reduction and spica cast immobilization recommendedtraction controversial with theoretical benefit of gradual stretching of soft tissues impeding reduction and neurovascular bundles to decrease AVNskin traction preferred however vary with surgeon usually 1-2 weeksscientific evidence supporting this is lackingTreatment contclosed reduction preformed in OR under general anesthetic manipulation includes flexion,traction and abductionpercutaneous or open adductor tenotomy necessary in most cases to increase safe zone which lessen incidence of proximal femoral growth disturbancereduction must be confirmed on arthrogram as large portion of head and acetabulum are cartilaginousdynamic arthrography helps with assessing obstacles to reduction and adequacy of reductionTreatmentreduction maintained in spica cast well molded to greater trochanter to prevent redislocationhuman position of hyperflexion and limited abduction preferredavoid forced abduction with internal rotation as increased incidence of proximal femoral growth disturbance cast in place for 6 weeks then repeat Ct scan to confirm reduction casting continued for 3 months at which point removed and xray done then placed in abduction orthotic device full time for 2 months then weanedFailure of Closed MethodsOpen reduction indicated if failure of closed reduction,persistent subluxation,reducible but unstable other than extremes of abductionvariety of approachesanterior smith peterson most commonallows reduction and capsular plication and secondary proceduresdisadv-blood loss,damage iliac apophysis and abductors,stiffnessgreatest rate of acetabular development occurs in first 18 months after reductionOpen Reduction contmedial approach(between adductor brevis and magnus)approach directly over site of obstacles with minimal soft tissue dissectionunable to do capsular plication so depend on cast for post op stabilityanteromedial approach Ludloff(between neurovascular bundle and pectineus)direct exposure to obstacles,minimal muscle dissectionno plication or secondary proceduresincreased incidence of damage to medial femoral circumflex artery and higher AVN riskFollow-up Abduction orthotic braces commonly used until acetabular development caught up to normal sidein assessing development look for accessory ossification centers to see if cartilage in periphery has potential to ossifysecondary acetabular procedure rarely indicated 3 femoral shortening recommended to avoid excess pressure on head with reduction54%AVN and 32%redislocation with use of skeletal traction in ages 3 age 3 recommend open reduction and femoral shortening and acetabular procedure Treatment cont2-3-years gray zonepotential for acetabular development diminished therefore many surgeons recommend a concomitant acetabular procedure with open reduction or 6-8 weeks afterJBJS Feb,2002 Salter Innominate OsteotomyBohm,Brzuske incidence of AVN is greater with simultaneous open reduction and acetabular procedureTreatment contLovell and Winter judge stability at time of reduction and if stable observe for period of time for developmentif not developing properly with decreased acetabular index,teardrop then consider secondary proceduremost common osteotomy is Salter or Pembertonanatomic deficiency is anterior and Salter provides this while Pemberton provides anterior and lateral coverageNatural Sequelae Goal of treatment is to have radiographically normal hip at maturity to prevent DJDafter reduction achieved potential for development continues until age 4 after which potential decreaseschild 4 minimal dysplasia may observe but if severe than subluxations and residual dysplasias shoild be correctedwhen evaluating persistent dysplasia look at femur and acetabulumDDH deficiency usually acetabular side Residual Dysplasiaplain xray with measurement of CE angle and acetabular indexyoung children deficiency anterior and adolescents can be globaldeformities of femoral neck significant if lead to subluxationlateral subluxation with extreme coxa valga or anterior subluxation with excessive anteversion(defined on CT)usually DDH patients have a normal neck shaft angleDysplasia for 2-3-years after reduction proximal femoral derotation or varus osteotomy should be considered if excessive anteversion or valgusprior to performing these be sure head can be concentrically reduced on AP view with leg abducted 30 and internally rotatedvarus osteotomy done to redirect head to center of acetabulum to stimulate normal developmentmust be done before age 4 as remodeling potential goes down after thisAdolescent or AdultFemoral osteotomy should only be used in conjunction with pelvic procedure as no potential for acetabular growth or remodeling but changing orientation of femur shifts the weightbearing portionPelvic osteotomy considerationsagecongruent reductionrange of motiondegenerative changesPelvic ProceduresRedirectionalSalter(hinges on symphysis pubis)Sutherland double innominate osteotomy Steel(Triple osteotomy)Ganz(rotational)Acetabuloplasties(decrease volume)hinge on triradiate cartilage(therefore immature patients)PembertonDega(posterior coverage in CP patients)Salvage depend on fibrous metaplasia of capsuleshelf and ChiariComplications of TreatmentWorst complication is disturbance of growth in proximal femur including the epiphysis and physeal platecommonly referred to as AVN however,no pathology to confirm thismay be due to vascular insults to epiphysis or physeal plate or pressure injury occurrs only in patients that have been treated and may be seen in opposite normal hipNecrosis of Femoral HeadExtremes of position in abduction(greater 60 degrees)and abduction with internal rotationcompression on medial circumflex artery as passes the iliopsoas tendon and compression of the terminal branch between lateral neck and acetabulum“frog leg position“uniformly results in proximal growth disturbanceextreme position can also cause pressure necrosis onf epiphyseal cartilage and physeal plateseverin method can obtain reduction but very high incidence of necrosismultiple classification systems with Salter most popularSalter Classification1 failure of appearance of ossific nucleus within 1 year of reduction22failure of growth of an existing nucleus within 1 year3broadening of femoral neck within 1 year4increased xray density then fragmentation of head5residual deformity of head when re-ossification complete including coxa magna,vara and short neckKalamachiClassified growth disturbances assoc with various degrees of physeal arrest1 all disturbances not assoc with physis2lateral physeal arrest (most common)3central physeal arrest4medial physeal arrestlongterm follow up shows that necrosis of femoral head decreases longevity of hipTreatmentFemoral and/or acetabular osteotomy to maintain reduction and shift areas of pr