gms | German Medical Science

73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

29.05. - 01.06.2022, Köln

The role of sitting flexion radiography to detect lumbar instability – comparison with neutral standing x-ray and supine MRI

Die Bedeutung der Röntgen-Funktionsaufnahme in sitzender Inklination in der Diagnostik lumbaler Instabilitäten – ein Vergleich mit seitlichem Röntgen im Stehen und konventionellem MRT

Meeting Abstract

  • presenting/speaker Laura Mühlhausen - Schön Klinik Hamburg-Eilbek, Spinale Chirurgie, Hamburg, Deutschland
  • Jens Lohmann - Schön Klinik Hamburg-Eilbek, Spinale Chirurgie, Hamburg, Deutschland
  • Ralph Kothe - Schön Klinik Hamburg-Eilbek, Spinale Chirurgie, Hamburg, Deutschland
  • Sven Opitz - Schön Klinik Hamburg-Eilbek, Fachzentrum für Radiologie, Hamburg, Deutschland
  • Karsten Schöller - Schön Klinik Hamburg-Eilbek, Spinale Chirurgie, Hamburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie. Köln, 29.05.-01.06.2022. Düsseldorf: German Medical Science GMS Publishing House; 2022. DocV033

doi: 10.3205/22dgnc041, urn:nbn:de:0183-22dgnc0419

Published: May 25, 2022

© 2022 Mühlhausen et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

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Objective: The optimal imaging modality to detect lumbar instability remains controversial. Flexion-extension X-rays are often used in clinical practice, but have their limitations due to poor reproducibility and underestimation of segmental motion in symptomatic patients. Comparison of supine MRI scans with standing radiographs seems to have a higher sensitivity. We hypothesize that the use of a sitting flexion X-ray in addition to MRI/standing radiography offers a benefit to detect lumbar instability.

Methods: Retrospective analysis of adult patients with known lumbar spondylolisthesis (SL) who received a sitting flexion X-ray (FRad, Figure 1 [Fig. 1]) according to a standardized protocol in addition to routine standing neutral radiography (NRad) and supine lumbar MRI (SMRI) between 04/2020 and 12/2020. For every lumbar segment with a SL we calculated a ratio (slip percentage; SP) of anterior displacement relative to the length of the caudal vertebral body. The SP was compared between SMRI vs. NRad as well as SMRI vs. FRad to determine the rate of instable (≥8% difference) SL. Furthermore, the disc angle (DA; angle between inferior and superior end plates of the cephalad and caudal vertebral bodies) was measured. The presence of facet joint effusions on axial MRI was analyzed overall and in segments with instable SL.

Results: N=98 patients (f: n=50) with a median age of 73 years were included in the study. N=155 SL segments were analyzed; the most commonly affected segment was L4/5. The overall mean SP was 11.1%±6.5% in SMRI, 11.4%±6.7% in NRad, and 15.5%±7.2% in FRad (p=0.0001). In L4/5 (n=72) we found a SP of 12.4%±6.5% in SMRI, 12.1%±6.7% in NRad, and 16.6%±7.2% in FRad, whereas in L5/S1 (n=12) the SP was 15.0%±6.2% in SMRI, 16.3%±6.6% in NRad, and 19.7%±6.7% in FRad. An instable SL was detected in 9.7% of segments when SMRI and NRad was compared, and in 25.3% when SMRI was compared with FRad (p=0.0005). The overall mean DA (n=36 analyzed segments) was 6.0°±4.1° in SMRI, 7.0%±4.3% in NRad, and 4.0%±4.2% in FRad (p=0.49). In 65% of segments facet joint effusion could be detected overall, and in 60% of patients with instable SL.

Conclusion: Sitting flexion radiography seems to offer a benefit in addition to comparison of neutral standing X-ray and supine MRI in the detection of lumbar translational instability. Facet joint effusions did not correlate with instability in our cohort.