What is the management of fibrous dysplasia?

Management of Fibrous Dysplasia

For skeletal fibrous dysplasia, most monostotic lesions require only clinical observation and patient education, while symptomatic or polyostotic disease should be treated with bisphosphonates for pain relief and fracture prevention, with surgery reserved for pathologic fractures, progressive deformity, or confirmatory biopsy. 1, 2

Initial Assessment and Diagnosis

When evaluating suspected fibrous dysplasia, confirm the diagnosis through:

• Plain radiographs showing characteristic "ground glass" radiolucent lesions within the medullary canal 3, 1
• Biopsy for histologic confirmation when diagnosis is uncertain or to rule out malignancy 1, 4
• Assessment of disease extent: Determine if monostotic (single bone) versus polyostotic (multiple bones) 1, 2
• Screen for McCune-Albright syndrome in polyostotic cases by evaluating for café-au-lait spots and endocrine dysfunction (precocious puberty, hyperthyroidism, growth hormone excess) 4, 2
• Evaluate for renal phosphate wasting, which commonly occurs in polyostotic disease 2

Non-Surgical Management

Observation Strategy

Asymptomatic monostotic lesions should be managed with clinical observation and patient education alone. 1, 4

• Monitor with serial radiographs to assess for progression 1
• Educate patients about fracture risk and activity modification 1
• Most monostotic lesions remain stable and do not require intervention 4

Bisphosphonate Therapy

Bisphosphonates are the primary medical treatment for symptomatic fibrous dysplasia. 1, 2

• Indications: Bone pain, multiple lesions, high fracture risk 1, 2
• Benefits: Improves cortical thickness, reduces pathologic fractures, relieves bone pain, and improves lytic lesions 3, 1, 2
• Timing: Most effective when initiated early in disease course 3
• Limitations: Does not alter the natural history of disease progression or prevent deformity 5

Supplemental Medical Therapy

• Calcium and vitamin D supplementation for all patients with polyostotic disease 2
• Phosphorus supplementation when renal phosphate wasting is documented 2
• Endocrine management for associated McCune-Albright syndrome manifestations 2

Surgical Management

Indications for Surgery

Surgery is indicated for: 1, 4

• Confirmatory biopsy when diagnosis is uncertain
• Pathologic fractures (acute or impending)
• Progressive skeletal deformity requiring correction
• Symptomatic lesions unresponsive to medical management
• Eradication of painful circumscribed lesions

Surgical Techniques by Clinical Scenario

Circumscribed Monostotic Lesions

For symptomatic circumscribed lesions, perform curettage with cryosurgery followed by bone grafting. 4

• This approach shows satisfactory functional and radiographic outcomes 4
• Use cortical bone grafts rather than cancellous grafts due to superior physical properties and better remodeling 1
• Avoid bone graft substitutes, which show inferior results 1

Pathologic Fractures

Conservative treatment with casting is effective for fractures, particularly in the upper extremities. 5

• Fracture healing is not compromised by fibrous dysplasia 5
• Cast immobilization alone often sufficient for upper limb fractures 5
• Lower extremity fractures may require surgical stabilization 5

Proximal Femoral Disease and Deformity

For proximal femoral involvement with shepherd's crook deformity, use angled blade plates with or without intertrochanteric valgus osteotomy. 3

• Angled blade plate fixation achieves 71% revision-free success 3
• Results in 91% of patients walking pain-free 3
• Alternative approach: Intertrochanteric valgus osteotomy with angled blade plate followed by cephalomedullary nail stabilization 3
• Prefer intramedullary devices over plates when anatomically feasible 5

Extended Polyostotic Lesions

For extended polyostotic lesions with deformity, perform corrective osteotomies with rigid internal fixation plus curettage, cryosurgery, and cortical bone grafting. 4

• Expected outcomes are good in polyostotic disease without McCune-Albright syndrome 4
• Outcomes are uniformly poor in McCune-Albright syndrome 4

Important Surgical Considerations

Bone grafting has significant limitations, particularly in younger patients. 3

• 75% of various graft types (struts, bone chips, freeze-dried grafts) fail to incorporate and are resorbed 3
• Failure rates are highest in patients younger than 18 years 3
• Strut allografts show 54% revision-free survival at 20 years for proximal femoral disease 3
• Despite limitations, cortical strut grafts remain the preferred option when grafting is necessary 1

Prognosis and Special Populations

• Monostotic disease: Generally excellent prognosis with observation or limited intervention 4
• Polyostotic disease: Good outcomes expected with appropriate medical and surgical management 4
• McCune-Albright syndrome: Uniformly poor outcomes despite aggressive treatment 4
• Malignant transformation: Occurs in less than 1% of cases, so prophylactic resection is not indicated 5
• Disease progression: Lesions increase in number and extent until approximately age 15, then typically stabilize 5

Critical Pitfalls to Avoid

• Do not use cancellous bone grafts or bone graft substitutes instead of cortical grafts 1
• Do not perform prophylactic surgery solely to prevent malignant transformation (risk <1%) 5
• Do not expect bone grafting to provide long-term stability in patients under 18 years 3
• Do not overlook screening for McCune-Albright syndrome in polyostotic cases 2
• Do not fail to assess and treat renal phosphate wasting in polyostotic disease 2