An intervertebral spacer for therapeutic treatment of a patient includes a link sized and dimensioned to fit within an intervertebral space in the patient, and is configured to maintain a separation of two adjacent vertebrae for a period of time. A rigid guiding object, which may be a tool or a successive link, is insertable into the patient, to guide the link into the patient using an MIS approach. A pivot is connected within the links configured to limit a relative range of angular orientation between the link and the guiding tool.