Perichondrial ring is:
The perichondrial ring- surrounds the growth plate circumferentially. Peri-chondrial ring extends towards metaphysis and become continuous with periosteum of metaphysis. With increasing age, perichondrial ring is thinned and its shear resistance (strength) is decreased.
Seen around foramen magnum
Seen around epiphyseal plate
More prominent in adults
Shear strength increases with age
Pediatric Ohopedics