Tibia adaptation after fibula harvesting: an in vivo quantitative study

Area of Science:

• Orthopedic surgery
• Bone biology
• Human physiology

Background:

• Fibula harvesting for upper limb reconstruction alters biomechanical loads on the donor tibia.
• Understanding bone adaptation to increased stress is crucial for patient outcomes.

Purpose of the Study:

• To quantify the densitometric and morphologic changes in the donor-side tibia after fibula excision.
• To analyze the bone adaptation process in young patients over a 27-43 month follow-up period.

Main Methods:

• Computed tomography (CT) examinations of both legs were used for three young patients.
• Three-dimensional models were generated to measure cross-sectional area, cortical thickness, and moment of inertia.
• Bone density and new bone formation were evaluated.

Main Results:

• The donor-side tibia demonstrated significant morphologic and density adaptation, with new bone filling the interosseous space.
• The second moment of area increased in the donor tibia, but did not fully match contralateral values.
• Bone adaptation was incomplete, with normal mineral density only achieved in the patient with the longest follow-up.

Conclusions:

• Young patients exhibit considerable tibial adaptation after fibula excision for limb reconstruction.
• Despite adaptation, mechanical properties and bone density may not fully recover within 43 months.
• Further long-term studies are needed to fully understand tibial adaptation after fibula autograft.