Dr N K Sinha & Dr Rajaram Pai [Manipal campus], Melaka-Manipal Medical College Malaysia

 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 sideNormal side

Skeletal survey of other bones did not reveal affection of other bones Blood investigations were within normal limits Workup

Monostotic fibrous dysplasia with pathological subtrochantric fracture right femur

 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 steps 1.Lateral based bone wedge excision 2.Sent for biopsy 3.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

 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

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