What is the detailed procedure for tumor exposure and excision in the surgical management of osteochondroma of the left humerus?

Detailed Procedure for Tumor Exposure and Excision in Osteochondroma of the Left Humerus

Complete surgical excision of osteochondroma with a covering of normal tissue is the optimal treatment approach to prevent local recurrence and restore structural integrity of the bone. 1

Preoperative Planning

• Complete imaging workup (plain radiographs, MRI, CT scan) is essential to assess:
  • Exact location and extent of the tumor
  • Proximity to neurovascular structures
  • Cartilaginous cap thickness (>2cm in adults or >3cm in children suggests malignant transformation) 2
  • Presence of soft tissue extension

Surgical Approach Selection

The surgical approach depends on the location of the osteochondroma:

• Anterolateral lesions: Deltopectoral approach (most commonly used - 61% of cases) 3
• Posteromedial lesions: Direct medial approach (achieves more complete excision - 79% vs 51% compared to other approaches) 3
• Posterolateral lesions: Posterior approach with careful dissection around the axillary nerve

Tumor Exposure Procedure

1. Skin Incision and Dissection:

   • Make an appropriate incision based on the tumor location
   • Carefully dissect through subcutaneous tissue and fascia
   • Identify and protect neurovascular structures (particularly important in proximal humerus)
   • Expose the tumor base and cartilaginous cap

2. Neurovascular Protection:

   • Identify and protect critical structures:
     • Axillary nerve (posterolateral approach)
     • Brachial plexus and axillary vessels (medial approach)
   • Use vessel loops or retractors to gently mobilize these structures away from the surgical field

Tumor Excision Procedure

1. Complete Resection:

   • For low-grade peripheral osteochondromas, excise the tumor with a covering of normal tissue 4
   • Ensure complete removal of the cartilaginous cap, which is essential to prevent recurrence 1
   • Use high-speed burr to smooth the bone surface after tumor removal

2. Margin Assessment:

   • For benign osteochondromas, intralesional or marginal excision is adequate
   • For suspected malignant transformation, wide surgical margins are required 4
   • Send specimens for histopathological examination

3. Bone Reconstruction (if needed):

   • For large defects that compromise bone integrity, consider:
     • Bone cement filling (for enchondromas and ACTs) 5
     • Bone grafting for structural support
     • Internal fixation if structural integrity is compromised

Technical Considerations and Pitfalls

• Posteromedial Lesions: These are technically challenging with lower rates of complete excision (average 68% of mass removed vs 92% for other locations) 3
• Vascular Compromise: Be vigilant for vascular involvement, as osteochondromas of the proximal humerus can potentially compromise vascular structures 6
• Recurrence Risk: Local recurrence is less than 2% if complete resection is achieved 2, but inadequate excision can lead to persistent postoperative pain 3

Surgical Outcomes

• Surgical excision leads to favorable results in most cases:
  • Resolution of preoperative symptoms in 93.4% of cases 7
  • Low complication rates (4.7% major complications) 7
  • Excellent functional outcomes with appropriate technique

Remember that complete excision of the cartilaginous cap is the most critical factor in preventing recurrence, and the surgical approach must be carefully selected based on tumor location to achieve optimal exposure and complete resection.