Regional Bone Density Analysis of Minimally Invasive Bunionette Fixation Target Sites.

Area of Science:

• Orthopedic surgery
• Foot and ankle surgery
• Minimally invasive procedures

Background:

• Minimally invasive hallux valgus correction is increasingly adopted for its reproducibility.
• Minimally invasive techniques are also popular for bunionette correction.
• Evaluating bone density in the fifth metatarsal head is crucial for surgical fixation.

Purpose of the Study:

• To assess regional bone density in the fifth metatarsal head using computed tomography (CT)-derived Hounsfield units (HUs).
• To identify the optimal fixation site for minimally invasive bunionette correction based on bone density.

Main Methods:

• Retrospective analysis of 30 patients undergoing CT scans.
• Fifth metatarsal head divided into four quadrants in the coronal plane.
• CT-derived HUs measured from a 3.5-mm region of interest in each quadrant.
• Statistical comparison of HU values using ANOVA and post hoc testing (P ≤ .05).

Main Results:

• Statistically significant differences in bone density were found among the four quadrants (P < .001).
• The dorsomedial quadrant exhibited the highest bone density (301.0 ± 76.4 HUs).
• Dorsomedial density was significantly greater than dorsolateral (186 ± 68 HUs), plantar medial (241 ± 69 HUs), and plantar lateral (214.0 ± 70 HUs) quadrants.

Conclusions:

• The dorsomedial quadrant of the fifth metatarsal head is the optimal target for fixation in minimally invasive bunionette correction.
• Surgeons should aim fixation trajectories toward the dorsomedial quadrant for enhanced stability.
• This anatomical insight supports reproducible and effective minimally invasive surgical techniques.