Department of Orthopaedics AFMC, Pune PG SEMINAR DEVELOPMENTAL DYSPLASIA OF HIP Maj Rohit Vikas Resident
CDH/ DDHInstability of the hip in the newbornIncludes Dislocatable hips Acetabular dysplasia Subluxation of femoral head Dislocated Femoral headAs the child grows it may Progress to dislocation or poor acetabular coverage Secondary changes develop in head and acetabulumProcess is not restricted to congenital abnormalitiesof the hip, and includes some hips that were normalat birth and subsequently became abnormal.
Which is an Unstable Hip?Positive Barlow/ Ortolani TestsClinically stable but abnormal USGAcetabular IndexLateral displacement of femoralbeak in relation to Perkin’s line
What is Dysplasia?Radiographic findingIncreased obliquity of acetabulumLoss of acetabular concavityIntact Shenton line
What is Subluxation?Femoral head not fully in contactwith acetabulumWidened Teardrop – femoral headdistanceReduced CE angleBreak in Shenton lineDysplastic changes in acetabulum
What is Dislocation?Femoral head not in contact withacetabulumDysplastic changes in acetabulum
Teratologic / Antenatal DislocationsFixed dislocation at birth with limited range of motion at hipDuring gestation the hip is at risk of dislocation during the 12th week when the lower limb rotates medially, during the 18th week as the hip muscles develop.Dislocations during these developmental stages are termed teratologic and arethe result of congenital abnormal neuromuscular development.Treatment unsuccessfulOpen Reduction at 6 months of age
Secondary Hip DysplasiaStrictly, DDH applies to idiopathic hip dysplasiaSecondary Hip dysplasia Neurological conditions Myelomeningocele Cerebral palsy Connective tissue diseases Ehlers-Danlos syndrome Myopathic disorders Arthrogryposis multiplex congenita.
DEVELOPMENTAL DYSPLASIA OF HIP ETIOPATHOGENESIS
INCIDENCE Breech delivery Frank Breech 20% incidence of DDHLeft hip > Bilateral > Right hip Complete orLowry, et al, showed that breech infants footling breechdelivered by elective caesarean section (pre- lower incidencelabor) had a lower incidence of DDH than of DDH (2%)those breech babies delivered vaginally
DEVELOPMENTAL DYSPLASIA OF HIP CLINICAL DETECTION OF DDH BIRTH TO 6 MONTHS
Asymmetrical Thigh Folds Indicative of Abnormal hips Also seen in infants with normal hips Widened perineum Prominent Greater trochanter
Galeazzi’s / Allis sign Limited Abduction In bilateral hip abnormality, asymmetry may not be a feature
Ortolani’s sign (Ortolani 1937, 1976). Hold the knees and abduct the hip while lifting up on the greater trochanter A positive test is feeling the dislocated hip clunk into the acetabulum
Barlow’s Provocative Test (Barlow,1962) Adduct and push posteriorly on the hip A positive test is feeling the hip push out of the acetabulum
Klisic sign in bilateral DDH The Ortolani and Barlow manoeuvres are the mainstay of clinical diagnosis in the first months of lifeEven in the best hands physical examination can fail to detect DDH, and after 3 monthsof age the Ortolani and Barlow tests become negative due to progressive soft tissuecontractures.
DEVELOPMENTAL DYSPLASIA OF HIP CLINICAL DETECTION OF DDH OLDER CHILD
Abduction becomes more limited which is particularly noticeable when there isunilateral disease.Femoral shortening (positive Galeazzi test) may be apparent but this can be difficultto appreciate with bilateral disease.Ambulatory children will have a Trendelenburg gait in addition to limited hipabductionTrendelenburg signTelescopy positiveExaggerated lumbar lordosis
DEVELOPMENTAL DYSPLASIA OF HIP NATURAL HISTORY
What happens to a Dysplastic hip without subluxation ?Usually become painfulDegenerative Arthritis over timeOften subluxate as degeneration progressesHips with Acetabular index > 35 will likely require hip replacement laterIf these hips are well reduced after primary treatment of DDH, with a greaterthan normal CE angle, risk of Degenerative arthritis decreases
What happens to a Subluxated hip?Always lead to symptomatic degenerative arthritisRapid progressionSevere subluxation – symptoms in 2nd decadeModerate subluxation – in 3rd to 4th decadeMild subluxation – in 5th to 6th decade
What happens to a completely dislocated hip?Symptoms much later than a subluxated hipMay never become painfulFalse acetabulum False acetabulum
Consequences of Persistent DysplasiaAbnormal gaitRestricted abductionReduced strengthIncreased rate of degenerative joint disease.Outcome of untreated unilateral DDH is less favorable compared with bilateraldisease Limb length discrepancy, Asymmetrical movement, strength Ipsilateral valgus knee.Degenerative joint disease tends to present earlier in subluxated hips than indysplastic hips without subluxation
Natural HistoryOver the age of 6 months spontaneous resolution of dysplasia is unlikelyUsually more aggressive treatment is required compared with younger children.Older children tend to have more advanced changes in the soft tissues and bonystructures.Changes in acetabulum Ossification is delayed Shallow, Anteverted Deficient anterolaterally.Changes in Femoral Head Delayed ossification Exaggerated femoral anteversion.
Natural HistoryA 16y /F with longstanding “missed” left DDH.The left femoral head articulates with a neo-acetabulum in the iliac bone.The left femoral shaft is reduced in diameter and there is wasting of the thigh muscles
DEVELOPMENTAL DYSPLASIA OF HIP PLAIN RADIOLOGY
Normal Hip Perkins’ lineacetabularindex Hilgenreiner’s line Shenton’s line
Normal Hip Acetabular index Angle between the acetabulum and hilgenreiner’s line It should be < 30 degrees in a newborn Center-edge angle of Wiberg Cannot be measured until the ossific nucleus appears Normal is > 10 degrees in children 6- 13 yrs
DDH Ossification centre Head of femur 2 and 7 months
DDH 8 month /F with left DDH. Left acetabulum is shallow and the hip is dislocated. Left proximal femoral ossification centre is small compared with the normal right side. The normal right acetabulum has a central depression and well-defined lateral edge. The acetabular teardrop is developing on the right but not on the dysplastic left side
L β Iliac Wing Femoral Head α T BonyDiagram showing hip anatomy on standard coronal US plane and lines Acetabularused to evaluate hip dysplasia using the Graf method. roofFemoral head (FH) is centred over the hypoechoic triradiate cartilage(T). The promontory is at the junction of the iliac wing (IL) and thebony acetabular roof (A). L, labrum.The alpha angle reflects the depth of the bony acetabular roof and is Standard coronal ultrasound of the normalformed by the intersection of the baseline (BL) and acetabular roof infant hip joint. The promontory is sharplyline (AL). In a normal mature hip the alpha angle is greater than 60°. defined and the bony acetabular roof isThe beta angle reflects cartilaginous coverage and is formed by the steep. The ossification centre for the femoralintersection of the baseline with the labral line (LL). A normal beta head has not yet developedangle is less than 55°
Not routinely performedEither performed before surgery or intraoperatively.Goal of arthrography in DDH is to demonstrate the position of the femoral head withrespect to other joint structures both at rest and during reduction or stress manoeuvresIt also outlines any deformities or obstructions to concentric reduction Inverted limbus, Capsular constriction, Pulvinar Hypertrophy Hypertrophied ligamentum teres
Arthrogram, made afterfifteen days of overheadtraction, showing the hipto be reduced. A square-shaped limbus (arrow) atthe superior pole of theepiphysis and markedcapsular distension areevident.
DEVELOPMENTAL DYSPLASIA OF HIP COMPUTED TOMOGRAPHY
Two main indications for CT in DDH:To document hip reduction post-operatively if a child is placed in a spicacastPre-operative planning in severelydysplastic hips that require correctiveprocedures. Axial CT scan following open reduction of the left hip. The left femoral metaphysis is not aligned with the acetabulum and the femoral head is displaced posteriorly. The spica cast was removed and patient underwent further manipulation under anaesthesia to achieve successful reduction
Distinct advantages over both CT and arthrography in pre-operative imaging inpatients with DDH.Ability to differentiate between different types of soft tissue which enablesvisualisation of unossified cartilage, ligaments, fat, muscle and fluid including those softtissues that present an obstruction to concentric reduction such as pulvinar, the labrumand joint capsule.Lack of ionising radiationMR imaging is more time-consuming than CT or arthrography.In newborns and infants sedation may be required, except if patents are in a spica castsince this limits movement.The main disadvantages of MR imaging is increased cost and limited availability
General Examination-Plagiocephaly,-Sternomastoid Tumour (Torticollis),-Feet for any congenital deformity
Hip ExaminationBarlow’s test (<3-4 months of age)Ortolani’s test (<3-4 months of age)Limitation of AbductionLeg length discrepancy (Galleazi test)Asymmetry of thigh foldsLimp in a walking child
RadiologyChildren <6 months - Ultrasound using Graf classification system Class Alpha angle Description I >60 Normal II 60-43 Immature/Dysplastic III <43 Subluxed/Dislocated IV Unmeasurable DislocatedChildren >6 months - Xrays.
Criteria for ScreeningClinical Screening for all neonates for Hip Instability.Careful screening for infants with risk factors: Family history of DDH Breech Torticollis Metatarsus adductus OligohydomniosScreening with USG Controversial As per AAP guidelines Female infants delivered breech Family history of DDH +
DEVELOPMENTAL DYSPLASIA OF HIP TREATMENT BIRTH – 6 MONTHS
IndicationsAll Dislocated hip that can be reduced (Ortolani’s sign) Start harness at the time of diagnosisHips that are located but can be subluxated (Barlow’s sign) Some may spontaneously stabilize, some may dislocate. Re-examine after few weeks before starting treatmentHips that are normal on clinical examination but abnormal on USG Close observation Repeat USG at 6 weeks of age Abnormal hips treated Graf II hips more likely to improve without treatment than Graf III/ IV hipsIrreducible hips Likely to fail treatment if initial coverage was < 20%
ApplicationFlexion – 120°Hyper flexion Femoral nerve palsy Inferior dislocation of headInadequate flexion < 90° Fails to reduce hipAbduction by gravity 1 4 3 2
Follow UpWeekly Follow up during harness treatmentChange size after 3-4 weeksUSG at 3-4 weeks If unreduced – discontinue treatment Examine under anaesthesia Arthrogram for cause of instability If hip reduced but can be dislocated Continue harness for 3-6 more weeksAfter 6 weeks of harness – USG with child out of harness. If reduced head – Wean/ discontinue harnessX rays at 3-4 monthsX rays at 1 yrAnnual Follow upFollow up till skeletal maturity (Late asymmetric epiphyseal closure – valgus femoral head and reduced coverage Acetabular dysplasia in 20%)
Problems in HarnessIf reduction not achieved with harness in 3 – 4 weeks then discontinue harness andother treatment started.PAVLIK DISEASE Prolonged positioning of dislocated hip in flexion and abduction Dysplasia increased - Flattening of posterior acetabulum Open reduction neededFemoral nerve palsy
DEVELOPMENTAL DYSPLASIA OF HIP TREATMENT 6 – 18 MONTHS
Goal of TreatmentObtain and maintain reduction without damaging femoral head Closed Reduction Open ReductionProblems Risk of Avascular Necrosis Growth potential of acetabulum declines with age (and hence remodelling potential)
Role of Pre Reduction TractionReduced risk of Avascular Necrosis 30% without Traction 15% with prereduction traction < 5% in Human position (flexion 90 and mild abduction)Reduced need for Open reductionPortable Home Traction for 2 – 3 weeks
Role of Pre Reduction Traction Bryant’s Traction
Closed ReductionGentle positioningDetermine Stability – Wider Zones of Safety
Adductor TenotomyIncreases the Zones of Safety by allowing wider range of abduction
Hip Spica Cast Flexion > 90 Abduction 30 – 40 acceptable as long as further abduction possible Slight internal rotation (10 – 15)
Hip Spica CastIntraop radiographConfirm reduction – USG/ CT ScanMRI – reduction and vascular status of head can both be assessedRemove cast after 6 weeks under anesthesiaAssess stability through moderate range of motion/ do not dislocate.Xray AP pelvis to confirm reductionReapply second cast for 6 weeks.Third cast/ Abduction splinting Usually applied for 6 more weeks and discontinue immobilization
Obstacles to Reduction• Extra- articular – Iliopsoas tendon – adductors• Intra-articular – inverted hypertrophic labrum – tranverse acetabular ligament – pulvinar, ligamentum teres – constricted anteromedial capsule espec in late cases• neolimbus is not an obstacle to reduction and represents epiphyseal cartilage that must not be removed as this impairs acetabular development
Open Reduction +/- CapsulorrhaphyFor unstable hipsWidened joint spaceApproachesMedial Approch v/s Anterior approachMinimum dissection Better exposureObstructions approached directly Capsulorrhaphy can be performedLimited exposureMedial femoral Cx Artery< 1 yr of age in older children
Open Reduction + Femoral Shortening If there is excessive pressure on femoral head when it is reducedConsider in a dislocated hip in > 2 yrs ageTo correct excessive anteversionTo place femoral head into Varus positionIntertrochanteric/ Subtrochantericosteotomy
Open Reduction + Innominate Osteotomy If there is need for added coverageAssess need:Hip in extension – neutral rotation –abductionIf > 30% head visible then innominateosteotomy requiredInnominate osteotomy in > 18 months. Salter / PembertonConsider femoral shortening forexcessive pressure on head
DEVELOPMENTAL DYSPLASIA OF HIP TREATMENT 18 – 36 MONTHS
Open ReductionEvaluate stability of hip during open reductionAssess need for added coverage Salter/ Pemberton pelvic osteotomyFor Children > 3 yrs, usually an acetabular procedure is needed to cover femoralhead adequately
DEVELOPMENTAL DYSPLASIA OF HIP TREATMENT 3 – 8 YEARS
ProblemsProximal head locationContracted musclesFemoral shortening required, greater shortening required for higher dislocationsPrimary acetabular repositioning osteotomy often needed Salter/ PembertonIn > 3 yr, an acetabular procedure needed to adequately cover the head
Open ReductionUpper age for Successful ReductionUnilateral dislocations Open reduction should be attempted till 9 – 10 yrs of age Gait asymmetryBilateral dislocations Upto 8 yrs Increased complication if both hips reduced Natural outcome of untreated B/L Dislocation better than results of treatment
PELVIC OSTEOTOMIESSimple osteotomies that Reposition the Acetabulum Salter Innominate Ostetomy Pemberton’s Acetabuloplasty Dega OsteotomyComplex Osteotomies that Reposition the Acetabulum Steel osteotomy Tonnis Osteotomy Ganz OsteotomySpherical Acetabular osteotomyOsteotomies that Augment the Acetabulum Chiari Osteotomy Shelf Procedures Staheli Slotted Acetabular Augmentation
Salter Innominate OsteotomyPrerequisite – concentrically reduced hipAcetabular dysplasiaFailure of acetabular index to improve within 2 yrs afterreductionPersistent dysplasia after 5 yrs of ageLikely hood of Degenerative osteoarthritis highFor 2 – 9 yrs of age(< 2 yrs – not enough iliac wings that are thick enough tosupport bone graft,> 9 yrs – acetabular fragment not adequately mobilized.Improves Acetabular index by avg 10°.
Pemberton’s AcetabuloplastyImproves anterior and lateral coverage of femoral headStable osteotomy, does not require Internal FixationHinges through triradiate cartilage, reduces the volumeof acetabulumContraindicated if acetabulum is small relative to femoralhead.Complication Closure of triradiate cartilage (very rare) Damage to acetabular growth areas if osteotomy too close to acetabulum
Pemberton’s Acetabuloplasty 6-year-old child underwent open reduction with capsular placation, femoral shortening, and a pelvic (Pemberton) osteotomy.
Dega OsteotomyIncreases acetabular coverage anteriorly, centrally and posteriorly.Placement of wedges determine the areas of coverage to be improved
Dega OsteotomyResidual acetabulardysplasia on rightside.
Steel Triple OsteotomyOsteotomies through ilium and both pubic rami.Increases anterolateral coverage(More than Salter)
Chiari OsteotomyUsed when other procedures cannotachieve a concentric reduction of hip.Controlled fracture through ilium withmedial displacement of acetabularfragment and the intact hip capsuleunder the ilium.Over time the hip capsule converts intofibrocartilage and becomes the newacetabular coverage.A Salvage surgery
DEVELOPMENTAL DYSPLASIA OF HIP TREATMENT > 8 YEARS
If Femoral head cannot be repositioned distally to the level of Acetabulum Palliative Salvage Surgeries Rarely, Femoral shortening + Pelvic OsteotomyDegenerative Arthritic Painful Hip Total Hip ReplacementRole of Arthrodesis Rarely used now for old unreduced dislocations Contraindicated in bilateral dislocationsBilateral Dislocations Leave hip unreduced Later do THRReduced hip but painful acetabular dysplasia Pelvic osteotomy