A physeal bar or partial premature physeal arrest is a result of injury or infection to an unfused physis. It consists of a bony bridge crossing the growth plate that results in growth disturbance and/or deformity.

These bars form when the cartilage barrier is breached as a result of infection or trauma, this abnormal connection of metaphysis and epiphysis can be fibrous or osseous.

The lower limbs are most susceptible more so the distal tibial physis due to its wavy contour (Kump's bump).

Physeal bar mapping can aid in management. Resection of the bar is considered if <50% of physis is involved.

During surgery a cortical window is created through which the surgeon can resect the bar, further fat or tissue is interposed at the operative site to prevent the bar from forming again.