Possible pathogenesis of calcaneal bone cysts

Area of Science:

• Orthopedic Surgery
• Radiology
• Pathology

Background:

• Calcaneal bone cysts exhibit distinct clinical features compared to long bone cysts.
• Previous research has primarily focused on the pathogenesis of long bone cysts, neglecting calcaneal variations.

Purpose of the Study:

• To investigate the pathogenesis of calcaneal bone cysts using radiological and pathological findings.
• To elucidate the origins and developmental mechanisms of these specific bone lesions.

Main Methods:

• Review of radiological imaging (plain radiographs, CT, MRI, cystography, bone scintigraphy) and pathological data.
• Analysis of 24 patients (18 males, 6 females) with calcaneal bone cysts, median age 13.0 ± 3.6 years.

Main Results:

• Cysts predominantly occupied the central triangular area of the calcaneus.
• Expanded foramen structures were observed in 75% of cases, correlating with the sinus tarsi artery.
• Hemorrhage and cholesterol clefts were common pathological findings, with limited leakage into the subtalar joint.

Conclusions:

• Calcaneal bone cyst formation is linked to the collapse of the sinus tarsi artery and subsequent hemorrhage.
• Mechanical factors, including biomechanically stress-free areas and poor bone remodeling, play a crucial role in cyst development and progression.