Safe zone for minimally invasive calcaneal osteotomy: an MRI study

Area of Science:

• Orthopedic Surgery
• Radiology
• Anatomy

Background:

• Hindfoot deformities necessitate surgical correction, often via calcaneal osteotomy.
• Minimally invasive techniques are increasingly preferred for calcaneal osteotomy.
• Identifying a neurovascular safe zone is crucial to prevent iatrogenic injury during these procedures.

Purpose of the Study:

• To define an anatomical safe zone for minimally invasive calcaneal osteotomy.
• To determine the distance of the medial neurovascular bundle from the Achilles tendon insertion.

Main Methods:

• Retrospective analysis of 100 ankle MRI studies.
• Independent assessment by three observers measuring neurovascular bundle distance.
• Statistical analysis including confidence intervals and intraclass correlation coefficient.

Main Results:

• The mean distance of the medial neurovascular bundle from the Achilles tendon insertion was 23.0 mm (range 18.2-28.5 mm).
• Mean inter-observer variation was 1.1 mm, with a strong inter-observer reliability (ICC=0.7).
• A safe zone of at least 18 mm (mean 23 mm) was identified.

Conclusions:

• A radiological safe zone for minimally invasive medial calcaneal osteotomy is established at a minimum of 18 mm from the Achilles tendon insertion.
• Preoperative planning should consider individual patient variations.
• This finding aids in reducing neurovascular complications during minimally invasive calcaneal osteotomies.