neck of femur

PAEDIATRIC FRACTURE NECK OF FEMUR

< 1% of all pediatric #<1 % of prevalence of hip # in adults.Exceedingly rare.

Difference from adult AnatomyProximal femoral epiphysis is at a risk of

fractureOrientation of trabeculae in femoral neck in

children is not along the stress linesSmooth Fracture surfaces, with very little

interlocking impaction closed reduction less stable.

Blood vessels to the femoral head are easily damaged, and a high incidence of AVN occurs in fractures in children than adults.

Growth arrest in the physis can cause shortening of up to 15% of the total extremity

Varus or valgus angulation of the femoral neck also can occur from arrest of only one side of the physis.

A child can tolerate immobilization much more readily than an adult, and thus more choices for treatment are available, including traction, a spica cast, and bed rest, in addition to operative treatment.

Fixation devices causes growth arrest.

MECHANISM OF INJURYAxial loading, torsion, hyperabduction or a

direct blow injury.Severe high energy trauma.Proximal femur in children is extremely

strongFracture after minor injury suggests weaker

bone.Bone cysts, infection.

Applied AnatomyDuring early childhood only a single

proximal femoral physis exists.During I yr of life medial portion grows

faster creating long neck.PFE begins to ossify at 4 – 6 months.Trochanteric apophysis – 4 yrs.PFP metaphyseal growth of the neckFusion of physis 14 – 16 yrs.

VASCULAR ANATOMY

Ligamentum teres little B.SAt birth Metaphyseal vessels predominate.Gradually diminish as physis develops. [barrier], non existent by 4 yrs.Lateral epiphyseal vessels –

posterosuperior & posteroinferior branches of MCFA

At intertrochanteric groove, MCFA branches in to the retinacular arterial system.

Capsulotomy does not damage B.S but violation of IT notch or LACV avascular.

At 3-4 yrs, lateral posterosuperior vessels appear to predominate.

PI & PS vessels persists through out life.Multiple small vessels coalesce with age.

Confluence of GT physis with capital femoral epiphysis along the superior femoral neck & unique vascular supply to CFE makes immature hip vulnerable to growth derangement & subsequent deformity after a fracture.

DELBET CLASSIFICATIONTYPE I : Transepiphyseal separation I A : With dislocation II B: With out dislocation.TYPE II : Transcervical fractureTYPE III : Cervicotrochanteric fracture.TYPE IV : Intertrochanteric fracture.

TYPE 1

TYPE 1 TRANSEPIPHYSEAL – through the physis

High energy trauma8 % of NOF In a new born during a difficult breach

delivery [proximal femoral epiphysiolysis] mistaken with DDH.

During CR of traumatic dislocations hip.50% @ with dislocation of CFE.(100%

complication) < 2 yrs of age better prognosis. AVN unlikely but other comp, can occur.

TYPE 2

TYPE 2 TRANSCERVICAL- through neck

46% of # NOFMost common typeDifficult to treat in spica.70% displaced at presentationIncidence of AVN related to initial

displacement.AVN 50% [ common comp].

TYPE 3

TYPE 3 CERVICOTROCHANTERIC – base of neck

Located at or above anterior IT line.2 nd most common.34% of NOF #AVN 20-30%Premature physeal closure 25%.Coxa vara 14%.

TYPE 4 INTERTROCHANTERIC

12 % of NOF #.Lowest complication rateGood healing.Nonunion & AVN rare.

Type 1 # in neonateExceedingly rareA strong suspicion, [F.H not visible]

pseudoparalysis & shortening – key for diagnosis.

holds the limb in flexed, abducted & ext. rotated.

DD – septic arthritis & hip dislocation.High riding PF metaphysis.USG.

Clinical featuresPain in the hip Shortened & externally rotated limb.Non displaced # walk with limp.

INVESTIGATIONS:X ray pelvis AP & Cross table lateral view.Any Break or offset of bony trabeculae near

Ward’s triangle impacted #.

Radioisotopic bone scan 48 hrs after onset, increased uptake in # site.

MRI detects # with in first 24 hrs.

TREATMENT type -IBased on age & fracture stability after

reduction.< 2 yrs with minimally displaced #, CR &

spica cast application.# tends to displace in to varus &

ext.rotation, limb should be in mild abduction & neutral rot.

Displaced # reduced by gentle traction, abduction & IR.

< 6-8 Yrs smooth pins> 8 Yrs cannulated cancellous screwsOlder children should undergo fixation even

undisplaced.Postop spica must in all except for

adolescents.Implants removed shortly # healing [8-12

wks]

TYPE 1 BOne attempt CR, if not immediate OR from

the side of dislocation.Generally posterolateral approach.

TYPE II & IIIAnatomic reduction & stable IF always indicated to minimize risk of complications.

Non displaced type 2 # in children < 5 yrs spica, wants close follow-up.

Open reduction Watson & Jones approachScrews to be inserted short of physis.If not good purchase penetrate the physis.Treatment of # is priority, growth disturbance

& LLD are secondary,

TYPE IVGood results with traction & spica,

regardless of displacement.Indications for IR - failure to maintain reduction - polytrauma - older childrenPediatric hip screw.

SURGICAL TIPSAlways predrill & tap before inserting

screws.Avoid crossing the physis but cross it if

necessary for stability.Postop, hip spica for 6-12 wks if < 10 yrs,

COMPLICATIONS:- Avascular necrosisMost serious & most frequentOverall prevalence 30%.Primary cause of poor results.Highest after type IB, II, III.Initial # displacement, damage to blood

vessels, # hematoma.

RATLIFF CLASSIFICATIONTYPE I : Involvement of whole head - most severe & most common form - poorest prognosis -damage to all lateral epiphyseal vesselsTYPE II: Partial involvement - localized damage to one or more LEV.TYPE III: an area of AVN from # to physis - damage to superior metaphyseal V. - rare but good prognosis.

X ray ; as early as 6 wks, decreased density of FH with widening of jt space.

Can develop as late as 2 yrs, so all pt to be followed for atleast 2 yrs.

Tc bone scanMRI; no AVN with in 6 wks ,it is unlikely to

occur.

Late stage

COXA VARA20-30% prevalenceLower in internal fixed pts.causes: malunion, AVN, premature physeal

closure or a combination of above.Raises GT in relation to FH causing

shortening of extremity & abductor lurch.Subtrochanteric valgus osteotomy if C.vara

persists > 2 yrs. [>110*, in > 8 yrs]

PREMATURE PHYSEAL CLOSURE28% of #Risk increases with penetration of fixation

devices or when AVNM.F after type II or III AVN.Shortening not significant except in

youngerTrochanteric epiphysiodesis – progressive

coxa vara.

NON UNION7% of #Not seen after type 1 & IVPrimary cause – failure to obtain or

maintain reduction.If the child had pain & no bridging new

bone at 3 months post injury.Subtrochanteric valgus osteotomy / rigid IR

+/- bone grafting.

othersInfections [1%]Chondrolysis [ hardware placed inside Jt].

STRESS FRACTURE Repetitive cycle loading of hip by new or

increased activity. Adolescent female athlete, anorexia

nervosa, & osteoporosis. X rays only reveal after 4-6 wks DEVAS classification1. Compression - non wt bearing, coxa

vara. 2. Tension – inherently unstable, insitu

fixation