Open-door cervical laminoplasty is widely used for cervical compressive myelopathy; however, postoperative axial neck pain and cervical kyphotic deformity remain major concerns due to posterior soft-tissue injury. We developed an exoscopic minimally invasive open-door laminoplasty (ExLAP) using an exoscope and mini plates. This study aimed to compare one-year postoperative outcomes of ExLAP with those of the conventional open technique.

Ninety patients who underwent open-door cervical laminoplasty were retrospectively reviewed. Forty patients were treated using ExLAP (E group), and 50 patients underwent the conventional Hirabayashi open-door technique (C group). ExLAP was performed through a small midline skin incision of approximately 35 mm using an exoscope, with complete preservation of the C2 and C7 semispinalis muscles. The conventional technique required an approximately 10-cm incision with partial or complete detachment of the C2 semispinalis muscle. Cervical lordosis was evaluated using plain radiographs preoperatively and at one year postoperatively. Postoperative axial neck pain and Japanese Orthopaedic Association (JOA) scores were also assessed. Mean cervical lordosis changed from 11.6° preoperatively to 12.1° at one year in the E group and from 7.8° to 1.7° in the C group, with mean changes of 0.5° and −6.1°, respectively (P < 0.001). Postoperative axial neck pain was observed in 11% of patients in the E group and 66% in the C group (P < 0.01). Mean JOA scores improved from 10.7 to 13.4 in the E group and from 10.4 to 12.7 in the C group, with recovery rates of 45% and 37%, respectively (P = 0.10).

ExLAP significantly reduces postoperative axial neck pain and better preserves cervical lordosis compared with the conventional technique. By minimizing posterior soft-tissue injury and fully preserving the C2 semispinalis muscle, ExLAP represents an effective minimally invasive alternative for cervical laminoplasty.