Fibrous Dysplasia


Fibrous Dysplasia PelvisFibrous dysplasia hip




Arrest in development of normal bone with weak fibro-osseous bone




Caused by somatic activating mutations in GNAS




Spectrum of disease

- Monostotic (75%) - single bone affected

- Polyostotic (25%) - multiple bones affected

- McCune-Albright Syndrome


McCune - Albright Syndrome



1.  Fibrous Dysplasia

2.  Cafe-au-Lait Spots

- irregular "Coast of Maine"

3.  Hyperfunctioning endocrinopathies

- precocious puberty

- hyperthyroidism

- growth hormone excess


Malignant transformation


Osteosarcoma / fibrosarcoma / MFH / Chondrosarcoma


Increased risk in polyostotic disease / McCune-Albright Syndrome


Qu et al Medicine 2015

- 15 / 542 (3%) cases of FD had malignant transformation




Usually non genetic inheritance


Natural history


Usually diagnosed in children and adolescents

Remains relatively unchanged throughout life




Bone pain


Long bones

- pathological fracture

- deformity / bowing

- limp

- leg length discrepancy


Craniofacial involvment

- slow growing painless masses

- cosmetic deformity / dental problems / vision and hearing loss


FD skull




Fibrous dysplasia hipFibrous dyplasiaFD ankle


Intramedullary lucent diaphyseal lesion with 'ground glass appearance'

- thinned, slightly bulged cortex

- ± endosteal scalloping

- may have angular deformity / bowing


Coxa vara and Shepherd's Crook deformity of proximal femur

- Shepherd's Crook - anterior bowing of femur

- secondary leg length discrepancy

- pain, difficulty walking


FD hipFD hip 2


Sabre tibia


FD tibia 1FD tibia 2


Pathological fracture


FD humerus #


Spine involvement / scoliosis


Leet et al JBJS Am 2004

- 62 patients with polyostotic FD

- 40% had scoliosis


Berglund et al J Bone Mineral Res 2018

- 138 patients with fibrous dysplasia / McCune Albright syndrome

- 61% scoliosis

- 35% moderate to severe

- no effect of bisphosphonates in reducing curve progression




Fibrous Dysplasia CTFD CT hip


Bone Scan


Skeletal survey - determine disease burden / polostotic




Low signal intensity T1 / High signal intensity T2


Fibrous dysplasia hipFD MRI 1FD hip MRI 2


Fibrous dysplasia hipFD hip MRIFD hip MRI 2




Fibrous tissue with irregular, randomly oriented bony trabeculae




Multidisciplinary team


Orthopedics / Endocrinology / Dentistry




Bertin et al Rev Endocr Metab Disord 2023

- systematic review and meta-analysis of bisphosphonates

- increased bone density and reduces bone pain


Surgical intervention



- deformity correction

- fracture prevention (>75% of cortical diameter)

- prevention deformity

- pathological fracture


Bone grafting


Bone grafting is of limited value with fibrous dysplasia


Guille et al JBJS Am 1998

- curettage and bone grafting of lesions

- 100% resorption of bone graft with recurrence of lesion

- osteotomy and fixation with reconstruction nail mainstay of treatment


Majoor et al CORR 2017

- cortical strut allograft for 30 patients with impending or fractures proximal femur

- 50% radiological resorption of graft


Corrective osteotomy / Intra-medullary nailing


Mainstay of treatment


Ippolito et al J Orthop Traumatol 2023

- 24 patients with 34 femurs and 14 tibias requiring intra-medullary nailing

- mean age 32

- osteotomy and deformity correction often required

- nonunion / delayed union / implant failure in 5 cases


FD 2FD 1


FD Humerus 1FD Humerus 2


FD Femur 1FD femur 3FD femur 2


FD Humerus 1FD Humerus 2


Proximal femur coxa vara and shepherds crook deformity


Ippolito et al JBJS Am 2015

- 11 cases

- initial osteotomy correction of coxa vara and fixation with hip plate

- later osteotomy and correction of shepherds crook / femoral bowing and insertion reconstruction nail

- improved pain and gait

- significant blood loss at both stages


Ippolito Surgical Technique


Kim et al Bone Joint J 2015

- 209 patients with FD of the proximal femur

- 12% developed osteoarthritis


Garceau et al Can J Surg 2020

- 10 hips in 9 patients with 6 year follow up

- osteotomy to correct coxa vara

- proximal femoral allograft used +/- strut allograft

- one revision due to poor bone stock and femoral implant subsidence


Fibrous Dysplasia Hip CT