What is the management plan for a 1.7 cm calcaneal intraosseous lipoma?

Management of Calcaneal Intraosseous Lipoma

For a 1.7 cm calcaneal intraosseous lipoma, observation is recommended if asymptomatic, while surgical intervention with curettage and bone grafting is indicated only if the patient is experiencing pain or if there is risk of pathological fracture. 1

Clinical Presentation and Diagnosis

• Calcaneal intraosseous lipomas are rare benign bone tumors with a predilection for adults between 30-60 years of age, with males affected in approximately two-thirds of cases 1
• Common presentations include:
  • Incidental finding (33% of cases) 1
  • Heel pain, sometimes with tenderness or swelling 1
  • Pain that may increase acutely after minor trauma 2
• Typical location: Base of the neck of the calcaneus (Ward's triangle) 1

Imaging Evaluation

• Ultrasound is the first-line imaging modality for initial assessment of soft tissue masses 3
• For intraosseous lesions, radiographs should be obtained first to identify the well-defined lytic lesion 4
• MRI is the preferred advanced imaging modality:
  • Shows hyperintense signals on both T1 and T2 sequences 4
  • Provides superior tissue characterization for fat-containing lesions 3
  • Helps delineate the extent of the lesion and relationship to surrounding structures 3
• CT scan can also establish the diagnosis by demonstrating fat-equivalent densities 1

Management Algorithm

For Asymptomatic Lesions:

• Continued observation is a reasonable clinical approach 1
• Regular clinical monitoring every 6-12 months 3
• Patient education on when to return sooner (growth, increased pain, changes in appearance) 3

For Symptomatic Lesions:

Surgical treatment is indicated when the lesion is:

1. Symptomatic (causing pain) 2
2. Larger than critical size (risk of pathological fracture) 2
3. Prone to pathological fracture 2

Surgical Options

When surgery is indicated, the following approaches can be considered:

1. Traditional Curettage and Bone Grafting

• Complete curettage of the lesion 5
• Filling the defect with:
  • Autogenous bone graft (typically from iliac crest) 5
  • β-tricalcium phosphate 2
  • Allogenic cancellous bone chips when autograft is insufficient 5, 6

2. Endoscopically-Assisted Curettage

• Minimally invasive approach through small bone fenestrations 4
• Uses a small diameter endoscope (2.7mm Hopkins telescope) 4
• Advantages:
  • Allows full weight-bearing the day after surgery 4
  • Minimizes risks of open surgery 6
  • Speeds up convalescence 6
  • Avoids long period of non-weight bearing post-operatively 4

Post-Surgical Outcomes

• Pain typically resolves soon after surgery in most cases 2
• Mean time to graft consolidation: approximately 5 months (range 3-7 months) 5
• Potential complications:
  • Mild chronic regional pain syndrome (short-term) in rare cases 2
  • Donor site pain (when iliac crest autograft is used) 5
• No recurrences or pathological fractures reported in long-term follow-up 5

Key Considerations

• Pathological fracture has not been reported in calcaneal lipomas, unlike in other locations 1
• The 1.7 cm size of this particular lesion should be evaluated in context of the overall calcaneal size and location to determine fracture risk
• β-tricalcium phosphate has shown excellent resorption and remodeling properties when used as graft material 2

For this specific 1.7 cm calcaneal intraosseous lipoma, the management decision should be based primarily on whether the patient is experiencing symptoms, with surgical intervention reserved for symptomatic cases or those at risk for pathological fracture.