The incident, involving a Land Rover, a quadbike and a car left four people injured.
They were all treated at the scene before one was taken to hospital by ambulance with head injuries.
The road was closed in both directions after last night’s smash, which left the Land Rover on its roof.
All four people in the vehicles managed to escape before police, ambulance and fire crews arrived at the scene.
The road, between the A6093 Mayfield and the B6367 Pathhead, was later reopened.
Meanwhile, a schoolboy was hurt after an accident involving a car.
It is understood he suffered leg injuries after the bicycle he was riding was involved in a collision with the car in Woodburn near Dalkeith.
His injuries were described as “non-life threatening”.