Navigated Minimally Invasive Cervical and Cervicothoracic Fixation: A Technical Note on Surgical Technique and Proposed Classification

The purpose of this study is to propose a standardized classification of minimally invasive cervical pedicle screw (MICEPS) fixation according to the levels instrumented and the extent of the construct, thereby facilitating reproducible surgical planning and technique. We developed a three-tiered MICEPS classification with a specific surgical algorithm based on anatomic levels and construct length: Type 1, subaxial cervical fixation; Type 2, subaxial cervical to proximal thoracic fixation; and Type 3, subaxial cervical to T3/4 cervicothoracic stabilization. All techniques employ O-arm intraoperative navigation and preserve posterior tension-band integrity. We describe key technical steps and compare each type in terms of incision strategy, soft-tissue handling, and navigation workflow. Each MICEPS type employs a tailored combination of small paramedian incisions, muscle-sparing dissection, and intraoperative navigation to achieve stable posterior fixation while minimizing soft-tissue trauma: Type 1 is indicated for short subaxial cervical fusions (typically C3-C6/C7). It uses a single small paramedian incision on each side of the spine and follows a purely muscle-sparing corridor. Type 2 extends the construct to T1 or T2, still via one paramedian incision per side, but involves splitting and subsequent re-approximation of the trapezius muscle. Type 3 reaches down to T3/T4, employing two mini-open incisions on each side and controlled splitting of the trapezius. All three techniques provide a safe, anatomically direct corridor without the need for significant retraction that could compromise navigation accuracy. The provided MICEPS classification offers a clear, anatomically driven framework for minimally invasive posterior cervical and cervicothoracic fixation. By tailoring incision number, muscle-sparing corridors, and navigated instrumentation to the required fusion extent, surgeons can achieve high-precision screw placement, minimal morbidity, expedited recovery, and high repeatability. Although a formal learning curve exists, MICEPS represents a safe, cost-effective alternative to open techniques in appropriately selected patients.