1、Developmental Dysplasia of the HipHeather RocheApril 4,2002 Previously known as congenital dislocation of the hip implying a condition that existed at birth developmental encompasses embryonic,fetal and infantile periods includes congenital dislocation and developmental hip problems including sublux
2、ation,dislocation and dysplasiaNormal Growth and Development Embryologically the acetabulum,femoral head develop from the same primitive mesenchymal cells cleft develops in precartilaginous cells at 7th week and this defines both structures 11wk hip joint fully formed acetabular growth continues thr
3、oughout intrauterine life with development of labrum birth femoral head deeply seated in acetabulum by surface tension of synovial fluid and very difficult to dislocate in DDH this shape and tension is abnormal in addition to capsular laxity The cartilage complex is 3D with triradiate medially and c
4、up-shaped laterally interposed between ilium above and ischium below and pubis anteriorly acetabular cartilage forms outer 2/3 cavity and the non-articular medial wall form by triradiate cartilage which is the common physis of these three bones fibrocartilaginous labrum forms at margin of acetabular
5、 cartilage and joint capsule inserts just above its rim articular cartilage covers portion articulating with femoral head opposite side is a growth plate with degenerating cells facing towards the pelvic bone it opposes triradiate cartilage is triphalanged with each side of each limb having a growth
6、 plate which allows interstitial growth within the cartilage causing expansion of hip joint diameter during growth In the infant the greater trochanter,proximal femur and intertrochanteric portion is cartilage 4-7 months proximal ossification center appears which enlarges along cartilaginous anlage
7、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 role sp
8、herical femoral head normal appositional growth within cartilage periosteal new bone formation in adjacent pelvic bones development of three secondary ossification centersnormal growth and development occur through balanced growth of proximal femur,acetabulum and triradiate cartilages and the adjace
9、nt 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 n
10、eck98%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
11、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 on age at reduction growth potential of acetabulum damage to acetabulum from head or during reductionaccessory ce
12、nters 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 disloca
13、tionmost 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%normalEtiologyGeneti
14、c 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 factors breech position(normal popn 2-4%,DDH 17-23%)oligohydroamnios neuromuscular conditions like myelomeningocelehigh association
15、 with intrauterine molding abnormalities including metatarsus adductus and torticollis first bornfemale baby(80%cases)left hip more commonDiagnosisClinical risk factorsPhysical exam Ortolani Test hip flexion and abduction,trochanter elevated and femoral head glides into acetabulum Barlow Test provoc
16、ative test where hip flexed and adducted and head palpated to exit the acetabulum partially or completely over a rim some base there treatment on whether ortolani+versus Barlow+feeling Barlow+more stable Lovell and Winter make no distinction 2%extreme complete irreducible teratologic disloactions as
17、soc with other conditions like arthrogyposisLate DiagnosisSecondary adaptive changes occurlimitation of abduction due to adductor longus shorteningGalleazi sign flex both hips and one side shows apparent femoral shorteningasymmetry gluteal,thigh or labial foldslimb-length inequailtywaddling gait and
18、 hyperlordosis in bilateral casesRadiographyUltra soundmorphologic assessment and dynamic anatomical characteristics alpha angle:slope of superior aspect bony acetabulum beta angle:cartilaginous component(problems with inter and intraobserver error)dynamic observe what occurs with Barlow and ortolan
19、i 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 treatmentR
20、adiography cont newborn period DDH not a radiographic diagnosis and should be made by clinical exam after newborn period diagnosis should be confirmed by xray several measurements treatment decisions should be based on changes in measurementsRadiological Diagnosis classic features increased acetabul
21、ar index(n=27,30-35 dysplasia)disruption shenton line(after age 3-4 should be intact on all views)absent tear drop sign delayed appearance ossific nucleus and decreased femoral head coverage failure medial metaphyseal beak of proximal femur,secondary ossification center to be located in lower inner
22、quadrant center-edge angle useful after age 5 (20)when can see ossific nucleus PeNatural Historyin NewbornsBarlow 1 in 60 infants have instability(positive Barlow)60%stabilize in 1st week 88%stabilize in 2 months without treatment 12%become true dislocations and persistColeman 23 hips 3 months 26%be
23、came dislocated 13%partial contact with acetabulum 39%located but dysplastic feature 22%normal because not possible to predict outcome all infants with instability should be treatedAdultsVariabledepends on 2 factors well developed false acetabulum(24%chance good result vs 52%if absent)bilateralityin
24、 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 problems leg length inequality,kne
25、e deformity,scoliosis and gait disturbanceDysplasia and SubluxationDysplasia(anatomic and radiographic defn)inadequate dev of acetabulum,femoral head or both all subluxated hips are anatomically dysplasticradiologically difference between subluxated and dysplastic hip is disruption of Shentons line
26、subluxation:line disrupted,head is superiorly,superolaterally ar laterally displaced from the medial wall dysplasia:line is intact important because natural history is differentNatural History ContSubluxation predictably leads to degenerative joint disease and clinical disability mean age symptom on
27、set 36.6 in females and 54 in men severe xray changes 46 in female and 69 in males Cooperman 32 hips with CE angle 6 months success 2-3-weeks)subgroup where failure may be predictable Viere et al absent Ortolani sign bilateral dislocations treatment commenced after age 7 week Treatment closed reduct
28、ion and Spica CastingFemoral Nerve Compression 2 to hyperflexionInferior Dislocation Skin breakdownAvascular Necrosis6 months to 2 years age Closed reduction and spica cast immobilization recommendedtraction controversial with theoretical benefit of gradual stretching of soft tissues impeding reduct
29、ion 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 op
30、en 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 adeq
31、uacy 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 pla
32、ce 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 subluxati
33、on,reducible but unstable other than extremes of abductionvariety of approaches anterior smith peterson most common allows reduction and capsular plication and secondary procedures disadv-blood loss,damage iliac apophysis and abductors,stiffness greatest rate of acetabular development occurs in firs
34、t 18 months after reductionOpen Reduction cont medial approach(between adductor brevis and magnus)approach directly over site of obstacles with minimal soft tissue dissection unable to do capsular plication so depend on cast for post op stability anteromedial approach Ludloff(between neurovascular b
35、undle and pectineus)direct exposure to obstacles,minimal muscle dissection no plication or secondary procedures increased 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 side
36、in 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 tr
37、action in ages 3 age 3 recommend open reduction and femoral shortening and acetabular procedure Treatment cont 2-3-years gray zone potential for acetabular development diminished therefore many surgeons recommend a concomitant acetabular procedure with open reduction or 6-8 weeks after JBJS Feb,2002
38、 Salter Innominate OsteotomyBohm,Brzuske incidence of AVN is greater with simultaneous open reduction and acetabular procedureTreatment cont Lovell and Winter judge stability at time of reduction and if stable observe for period of time for development if not developing properly with decreased aceta
39、bular index,teardrop then consider secondary procedure most common osteotomy is Salter or Pemberton anatomic 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
40、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 def
41、iciency 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 subluxation lateral subluxation with extreme coxa valga or anterior subluxa
42、tion with excessive anteversion(defined on CT)usually DDH patients have a normal neck shaft angle Dysplasia for 2-3-years after reduction proximal femoral derotation or varus osteotomy should be considered if excessive anteversion or valgus prior to performing these be sure head can be concentricall
43、y reduced on AP view with leg abducted 30 and internally rotated varus osteotomy done to redirect head to center of acetabulum to stimulate normal development must be done before age 4 as remodeling potential goes down after thisAdolescent or Adult Femoral osteotomy should only be used in conjunctio
44、n with pelvic procedure as no potential for acetabular growth or remodeling but changing orientation of femur shifts the weightbearing portion Pelvic osteotomy considerations age congruent reduction range of motion degenerative changesPelvic Procedures Redirectional Salter(hinges on symphysis pubis)
45、Sutherland double innominate osteotomy Steel(Triple osteotomy)Ganz(rotational)Acetabuloplasties(decrease volume)hinge on triradiate cartilage(therefore immature patients)Pemberton Dega(posterior coverage in CP patients)Salvage depend on fibrous metaplasia of capsule shelf and ChiariComplications of
46、Treatment Worst complication is disturbance of growth in proximal femur including the epiphysis and physeal plate commonly referred to as AVN however,no pathology to confirm this may be due to vascular insults to epiphysis or physeal plate or pressure injury occurrs only in patients that have been t
47、reated and may be seen in opposite normal hipNecrosis of Femoral Head Extremes of position in abduction(greater 60 degrees)and abduction with internal rotation compression on medial circumflex artery as passes the iliopsoas tendon and compression of the terminal branch between lateral neck and aceta
48、bulum“frog leg position“uniformly results in proximal growth disturbance extreme position can also cause pressure necrosis onf epiphyseal cartilage and physeal plate severin method can obtain reduction but very high incidence of necrosis multiple classification systems with Salter most popularSalter
49、 Classification 1 failure of appearance of ossific nucleus within 1 year of reduction2 2failure of growth of an existing nucleus within 1 year 3broadening of femoral neck within 1 year 4increased xray density then fragmentation of head 5residual deformity of head when re-ossification complete includ
50、ing coxa magna,vara and short neckKalamachi Classified growth disturbances assoc with various degrees of physeal arrest 1 all disturbances not assoc with physis 2lateral physeal arrest (most common)3central physeal arrest 4medial physeal arrest longterm follow up shows that necrosis of femoral head
