What is the step-by-step procedure for tumor excision and fibula bone grafting for osteochondroma of the left humerus?

Surgical Procedure for Osteochondroma of Left Humerus: Tumor Excision and Fibula Bone Grafting

The surgical management of osteochondroma of the left humerus requires complete excision with wide margins followed by fibula bone grafting to restore structural integrity and function of the affected limb.

Preoperative Evaluation

• Complete imaging workup including:

  • Plain radiographs of the humerus (AP and lateral views)
  • MRI to assess cartilage cap thickness and soft tissue extension
  • CT scan to define cortical and medullary continuity with parent bone
  • Chest imaging to rule out pulmonary metastases
  • Bone scan to exclude other lesions 1

• Laboratory tests:

  • Complete blood count
  • Basic metabolic panel
  • Coagulation profile

• Biopsy planning:

  • Core needle biopsy along the same incision line planned for definitive surgery 1
  • Collaboration between surgeon, musculoskeletal oncologist, and bone pathologist

Surgical Procedure Step-by-Step

Step 1: Patient Positioning and Preparation

• Position patient supine with the affected arm extended on a radiolucent table
• Prep and drape the entire upper extremity, shoulder, and ipsilateral leg (fibula donor site)
• Apply tourniquet to the upper arm (if feasible based on tumor location)

Step 2: Surgical Approach to the Humerus

• Make an incision based on tumor location:
  • For anterolateral lesions: deltopectoral approach
  • For posteromedial lesions: direct medial approach (provides better access for complete excision) 2
• Carefully identify and protect neurovascular structures
• Expose the osteochondroma while maintaining a cuff of normal tissue around it

Step 3: Tumor Excision

• Perform wide excision with negative surgical margins to minimize local recurrence 1
• Remove the entire lesion including the cartilaginous cap
• For posteromedial lesions, ensure maximum excision (aim for complete removal) 2
• Send specimen for histopathological examination
• Assess the resulting bone defect

Step 4: Fibula Harvest

• Make a lateral incision over the middle third of the fibula
• Identify and protect the common peroneal nerve
• Expose the fibula while preserving at least 6 cm of distal fibula to maintain ankle stability
• Harvest the required length of fibula (based on humeral defect)
• Close the donor site in layers after ensuring hemostasis

Step 5: Fibula Bone Grafting

• Prepare the harvested fibula graft to fit the humeral defect
• Position the graft in the defect
• Secure the graft with appropriate internal fixation:
  • Plate and screws for metaphyseal defects
  • Intramedullary fixation for diaphyseal defects
• Consider cement augmentation during fixation for additional stability 3

Step 6: Closure

• Irrigate the wound thoroughly
• Achieve meticulous hemostasis
• Close the wound in layers
• Apply sterile dressing and immobilize the arm

Postoperative Care

• Immobilize the arm for 2-3 weeks
• Begin passive range of motion exercises after initial healing
• Progress to active range of motion at 4-6 weeks
• Start strengthening exercises at 8-12 weeks
• Follow-up imaging at 6 weeks, 3 months, 6 months, and then annually
• Surveillance with physical examination and imaging of the surgical site every 6-12 months for 2 years, then yearly 1

Potential Complications and Management

• Neurovascular injury: Careful dissection and protection of structures during surgery
• Incomplete excision: Use direct approach based on tumor location to maximize visualization 2
• Recurrence: Wide surgical margins to minimize risk (2-6% recurrence rate)
• Donor site morbidity: Preserve adequate distal fibula, protect peroneal nerve
• Malignant transformation: Occurs in approximately 1% of solitary osteochondromas, requires wide surgical excision if detected 1
• Peroneal nerve injury: Most common complication (12.5% complication rate reported) 4

Special Considerations

• For posteromedial humeral lesions, a direct medial approach leads to more complete excision (79% vs 51% with other approaches) 2
• Despite risks of neurovascular injury, complete excision is essential to prevent recurrence and persistent pain
• Consider VTE prophylaxis according to ASCO, ASH, and ICM-VTE guidelines for patients with cancer undergoing major surgery 3

This procedure provides excellent outcomes with low recurrence rates when performed with adequate surgical margins, while preserving limb function and minimizing complications.