A modular drill guide for use in securing a pedicle screws drilling is provided. The drill guide consists of a holder extending to a pair of templates, and a pair of sleeves for guiding drill into the planning path. The templates permit customization to fit a specific patients vertebral anatomy. For a good contact between template and tissue, a hook-shape at the edge of template was designed to seize on the surfaces of vertebra. Sleeves were designed to ensure drilling followed the trajectory. The sleeves were offset a distance above the bone surface, to allow orientation guide for drill tip entry. This design aims at cervical, thoracic and lumbar spine. It generally increases the accuracy and safety in pedicle screw insertion.
