Fibrous dysplasia with pathological fracture of

proximal femur in a 25 year old lady

Dr N K Sinha &

Dr Rajaram Pai [Manipal campus],Melaka-Manipal Medical College

Malaysia

Case history & clinical examination

A 25 year old lady sustained a trivial fall at home

Unable to walk after the fall There was acute pain,swelling,

deformity and abnormal mobility in upper part of her right thigh

When asked further, the patient gave a history of shorter right lower limb and restriction of right hip abduction since long

Xray AP pelvis with both hips : Pathological fracture right hip with coxa vara

The femur was bent laterally Cortex was thinned and expanded Neck shaft angle was reduced Proximal femur was having a

ground-glass appearance

Traction AP view both hips showed

Fracture side Normal side

Skeletal survey of other bones did not reveal affection of other

bones

Blood investigations were within normal limits

Workup

Provisional diagnosis

Monostotic fibrous dysplasia with pathological subtrochantric fracture right femur

Operative procedure

Laterally based wedge was resected from distal fragment

Medullary canal was reamed Internal fixation was done with 135º

dynamic hip screw Concellous bone graft was harvested

from contralateral iliac crest - packed at fracture site and medullary canal to promote union

1

2

3 Operative steps1. Lateral based bone

wedge excision2. Sent for biopsy3. Wedge closure by

abduction

Post op day 1

Bone graft

135º

Post operative xray

14 week post-op

23 weeks post op :Union & leg length restoration

Discussion

Fibrous dysplasia is a developmental disorder

There is replacement of bony structure by relatively avascular fibrous tissue within which thin trabacular bone is scattered

Skeletal affection 70 % monostotic 20% polyostotic 2-3% have associated

endocrinopathy that manifests as pricocious sexual development, cafe-au-lait spots (Albright’s syndrome)

Monostotic fibrous dysplasia affects rib, femur, tibia gnathic bone, calvarium, humerus

Polyostotic fibrous dysplasia affects skull, facial bones, pelvis , spine and shoulder girdle

Polyostotic fibrous dysplasia maybe unilateral/ bilateral

Does not affect the epiphysis Diaphysis and metaphysis are affected

Gross pathology Affected bone is irregular and bent Cortex is thin and expanded The fibrous tissue appears reddish

gray/gray Feels like a fine sand paper Pathological fracture might occur but

does not displace because of fibrous tissue.

The femur may have outward bowing and varus deformity at neck that produces shephard’s crook deformity

Microscopy Microscopic areas of woven bone scattered in

cellualar fibrous tissue Giants cells may be seen at the areas of

hemosiderin deposits Cartilage is seen at the areas of cystic

degeneration

Small single lesion may be asymptomatic

Disease starts in childhood (before 10 years) and may progress till puberty

Incidentally discovered on x-ray Bending deformity may develop in

weight bearing bone followed by pathological fracture

Affection of skull may cause asymmetry, cranial nerve involvement

Blood investigations are normal in most of the cases

X-ray shows a radiolucent ‘cystic’ area in the metaphysis or shaft giving a hazy or ground glass appearance

Sometimes there are cystic multilocular lesions causing scalloped endosteal erosion and osseous expansion

Investigation

It can progress rapidly or slowly causing deformity, pain or fractures

Malignant changes are 5-10 % in polyostotic lesion

Majority of pathological fractures unite with treatment

Natural history

It has a strong tendency to recur

Large cystic lesion may bleed profusely during surgery

Points to consider during surgery

Reference

Apley’s System of Orthopaedics and Fractures,8th edition,Oxford university press inc.,New York