Devices, systems and methods for minimally open orthopedic spine surgery are disclosed. A first flexible screw-based retractor is designed to be coupled to each pedicle screw inserted into adjacent vertebral bodies. A retractor system is provided in which a first retractor blade is mounted to one of the screws and a second movable retractor blade is moved away from the first blade, in a medial direction, to create a working channel through which the disc space may be accessed for passing instruments and implants. Light may be incorporated into the device to illuminate the surgical field. One or all of the retractor blades may be made of a sterilizable plastic or metal and be disposable or reusable.