Accuracy, complications, and outcomes of dual-pin reference frame placement in navigated minimally invasive transforaminal lumbar interbody fusion.
| Publication Type | Academic Article |
| Authors | Ikwuegbuenyi C, Willett N, Hamad M, Kramer A, Bratescu R, Kharas N, Robayo A, Elsayed G, Hussain I, Kashlan O, Härtl R |
| Journal | J Neurosurg Spine |
| Pagination | 1-10 |
| Date Published | 09/18/2026 |
| ISSN | 1547-5646 |
| Abstract | OBJECTIVE: Percutaneous dual-pin reference frames (RFs) enable image-guided minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) but carry risks of pin-related morbidity, notably sacroiliac (SI) joint dysfunction. While single-pin systems have been studied, clinical data on dual-pin systems remain limited. The authors report on their experience identifying complications related to dual-pin placement and evaluating their distribution using a three-zone anatomical grading system (green, yellow, red). METHODS: This study retrospectively reviewed 133 consecutive patients who underwent MI-TLIF with intraoperative CT-guided dual-pin placement between January 2019 and July 2023, with at least 1 month of clinical follow-up. Pin-related complications assessed included new SI joint pain, persistent pin-site pain, hematoma, infection, fracture, and visceral injury. Two independent, blinded spine surgeons graded 266 total pins into one of three anatomical zones: 1) the green zone, involving the medial posterior superior iliac spine/ilium; 2) the yellow zone, abutting or breaching the SI joint or with inadequate bone purchase; and 3) the red zone, comprising the sacrum, neural foramen, or pelvic cavity. Interrater reliability was calculated using quadratic-weighted Cohen's kappa. RESULTS: Two patients (1.5%) developed new SI joint pain with confirmed SI joint penetration on the symptomatic side, and 1 patient (0.8%) reported persistent pin-site pain. No hematomas, infections, fractures, or vascular or visceral injuries were observed. All complications occurred exclusively in the yellow or red zones. Among the 266 RF frame pins evaluated, 192 (72.2%) were in the green zone, 63 (23.7%) in the yellow zone, and 11 (4.1%) in the red zone. Interrater reliability for zone assignment was excellent (quadratic-weighted Cohen's κ = 0.89 and 0.90 for inferior and superior pins, respectively; p < 0.001). CONCLUSIONS: Dual-pin RF placement using an institution-defined three-zone classification showed high interobserver reliability and a low complication rate. Although 72.2% of pins were placed in the green zone, clinically significant SI region dysfunction on the pin side occurred in only 1.5%. These findings support the safety of dual-pin systems while underscoring the need for continued refinement of placement technique and further evaluation of alternative fixation methods. |
| DOI | 10.3171/2026.3.SPINE25807 |
| PubMed ID | 42759056 |