Spinopelvic sagittal imbalance as a risk factor for adjacent-segment disease after single-segment posterior lumbar interbody fusion

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>The importance of spinopelvic balance and its implications for clinical outcomes after spinal arthrodesis has been reported in recent studies. However, little is known about the relationship between adjacent-segment disease (ASD) after lumbar arthrodesis and spinopelvic alignment. The purpose of this study was to clarify the relationship between spinopelvic radiographic parameters and symptomatic ASD after L4–5 single-level posterior lumbar interbody fusion (PLIF).</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>This was a retrospective 1:5 matched case-control study. Twenty patients who had undergone revision surgery for symptomatic ASD after L4–5 PLIF and had standing radiographs of the whole spine before primary and revision surgeries were enrolled from 2005 to 2012. As a control group, 100 age-, sex-, and pathology-matched patients who had undergone L4–5 PLIF during the same period, had no signs of symptomatic ASD for more than 3 years, and had whole-spine radiographs at preoperation and last follow-up were selected. Mean age at the time of primary surgery was 68.9 years in the ASD group and 66.7 years in the control group. Several radiographic spinopelvic parameters were measured as follows: sagittal vertical axis (SVA), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and segmental lordosis at L4–5 (SL) in the sagittal view, and C7–central sacral vertical line (C7-CSVL) in the coronal view. Radiological parameters were compared between the groups.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>No significant change was found between pre- and postoperative radiographic parameters in each group. In terms of preoperative radiographic parameters, the ASD group had significantly lower LL (40.7° vs 47.2°, p &lt; 0.01) and significantly higher PT (27° vs 22.9°, p &lt; 0.05) than the control group. SVA ≥ 50 mm was observed in 10 of 20 patients (50%) in the ASD group and in 21 of 100 patients (21%, p &lt; 0.01) in the control group. PI-LL ≥ 10° was noted in 15 of 20 patients (75%) in the ASD group and in 40 of 100 patients (40%, p &lt; 0.01) in the control group on preoperative radiographs. Postoperatively, the ASD group had significantly lower TK (22.5° vs 30.9°, p &lt; 0.01) and lower LL (39.3° vs 48.1°, p &lt; 0.05) than the control group had. PI-LL ≥ 10° was seen in 15 of 20 patients (75%) in the ASD group and in 43 of 100 patients (43%, p &lt; 0.01) in the control group.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Preoperative global sagittal imbalance (SVA &gt; 50 mm and higher PT), pre- and postoperative lower LL, and PI-LL mismatch were significantly associated with ASD. Therefore, even with a single-level PLIF, appropriate SL and LL should be obtained at surgery to improve spinopelvic sagittal imbalance. The results also suggest that the achievement of the appropriate LL and PI-LL prevents ASD after L4–5 PLIF.</jats:p></jats:sec>

Adjacent-segment disease following two-level axial lumbar interbody fusion

“…Other studies have also reported similar results. 5,21 Together, these findings suggest that failure to maintain physiological sagittal balance may be an important risk factor for the development of ASD. However, the causality is not established in this study, and it is possible that the ASD leads to further loss of lordosis.…”

State of the union: a review of lumbar fusion indications and techniques for degenerative spine disease

“…49, 73,74,91 Given the mounting evidence linking sagittal balance to outcomes and progression of spinal disease, including adjacent-segment disease, even the degenerative spine surgeon performing a single-level fusion should consider and account for lumbopelvic and global sagittal parameters. 95…”

Sagittales Profil der Wirbelsäule: Was ist sinnvoll, was gefährdet den Patienten, was ist Hype ? Pro: Korrektur ist oberste Maxime

“…Daher gilt es auch bei sog. "kleinen" und "kurzstreckigen" Fusionseingriffen Balance zu bewahren und Alignment zu beachten [16,18] (▶ Abb. 6a-d).…”

“…Nachdem die publizierte Literatur und der erlebte klinische Alltag gezeigt haben, dass bei langstreckigen Fusionen der Wiederherstellung der sagittalen Balance eine immense Bedeutung zukommt, haben Studien ihren Einfluss auch bei kurzstreckigen Fusionseingriffen im Bereich der degenerativen [16,18] technischen Standards ist erprobt und auch recht einfach umsetzbar.…”

“…Fakt ist, dass die fehlende Einstellung physiologischer Segmentverhältnisse im degenerativen Fusionsfeld zur Kompensation in Nachbarbereichen führt. Eine beschleunigte Anschlussdegeneration mit klinischer Dekompensation kann die Folge sein[16,18]. Die Korrektur des sagittalen regionalen Profils ist bei einer Folgeoperation dann erschwert.…”