Unilateral biportal endoscopic-assisted posterior atlantoaxial facet joint fusion (UBE-PALF): a technical report with initial experience in three adult patients
Year: 2026
Type: article
Study design: Case Report
Abstract: Atlantoaxial instability and dislocation (AAI/D) are potentially disabling conditions for which posterior C1-2 fixation and fusion is the standard treatment. The conventional open Goel-Harms technique requires extensive detachment of the suboccipital muscles, with postoperative axial neck pain reported in 18-60% of patients and a mean blood loss of 364 mL in a meta-analysis. This report describes the surgical technique of unilateral biportal endoscopy (UBE)-assisted posterior atlantoaxial facet joint fusion (UBE-PALF) and presents initial clinical experience in three adults with reducible AAI/D, whose diagnoses comprised rheumatoid arthritis-related instability, os odontoideum with a left high-riding vertebral artery, and odontoid fracture nonunion. The patients were aged 41-71 years and presented mainly with occipitocervical pain; the reducibility of each dislocation was confirmed preoperatively by dynamic radiographs or traction. Using a paramedian intermuscular approach through the plane between the trapezius, splenius capitis, semispinalis capitis, and obliquus capitis inferior muscles, the procedure was performed sequentially under continuous saline irrigation and endoscopic visualization: prophylactic hemostasis of the venous plexus, removal of the C1-2 articular cartilage, implantation of a polyetheretherketone (PEEK) cage, and C1 lateral mass/C2 pedicle screw fixation. All three procedures were completed without conversion to open surgery. Operative time was 60-138 min and blood loss 30-70 mL. At 3 months, the visual analogue scale (VAS) score improved from 5-7 to 1-2 and the Japanese Orthopaedic Association (JOA) score improved from 12-13 to 15-16; postoperative computed tomography showed satisfactory implant and cage positions, and no dural, vertebral artery, nerve root, or infectious complications occurred. To our knowledge, this is the first case series to combine UBE with PEEK cage structural grafting for bilateral C1-2 facet joint fusion in adults with reducible AAI/D. UBE-PALF offers potential technical advantages-direct visualization of the C2 pedicle cortical margins, endoscopically guided cartilage preparation with structural grafting, and irrigation-facilitated venous plexus control-but definitive fusion and superiority over established techniques cannot be established from three cases with short follow-up.
Source: Journal of Spine Surgery
Authors: Dongfang Yang, Yutong Hu, Haibin Zhang, Weibing Xu
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7223862881