European Spine Journal
Relationship between sagittal balance and adjacent segment
disease in surgical treatment of degenerative lumbar spine disease:
meta‑analysis and implications for choice of fusion technique
· Alexander Nazareth
· Awais K. Hussain
· Adam A. Dmytriw
· Mithun Nambiar
· Damian Nguyen
· Steven Phan
· Chet Sutterlin III
· Samuel K. Cho
· Ralph J. Mobbs
Received: 30 July 2017 / Revised: 24 April 2018 / Accepted: 6 May 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Study design Meta-analysis.
Objective To conduct a meta-analysis investigating the relationship between spinopelvic alignment parameters and develop-
ment of adjacent level disease (ALD) following lumbar fusion for degenerative disease.
Summary of background data ALD is a degenerative pathology that develops at mobile segments above or below fused
spinal segments. Patient outcomes are worse, and the likelihood of requiring revision surgery is higher in ALD compared to
patients without ALD. Spinopelvic sagittal alignment has been found to have a signiﬁcant eﬀect on outcomes post-fusion;
however, studies investigating the relationship between spinopelvic sagittal alignment parameters and ALD in degenerative
lumbar disease are limited.
Methods Six e-databases were searched. Predeﬁned endpoints were extracted and meta-analyzed from the identiﬁed studies.
Results There was a signiﬁcantly larger pre-operative PT in the ALD cohort versus control (WMD 3.99, CI 1.97–6.00,
p = 0.0001), a smaller pre-operative SS (WMD − 2.74; CI − 5.14 to 0.34, p = 0.03), and a smaller pre-operative LL (WMD
− 4.76; CI − 7.66 to 1.86, p = 0.001). There was a signiﬁcantly larger pre-operative PI-LL in the ALD cohort (WMD 8.74;
CI 3.12–14.37, p = 0.002). There was a signiﬁcantly larger postoperative PI in the ALD cohort (WMD 2.08; CI 0.26–3.90,
p = 0.03) and a larger postoperative PT (WMD 5.23; CI 3.18–7.27, p < 0.00001).
Conclusion The sagittal parameters: PT, SS, PI-LL, and LL may predict development of ALD in patients’ post-lumbar fusion
for degenerative disease. Decision-making aimed at correcting these parameters may decrease risk of developing ALD in
Graphical abstract These slides can be retrieved under Electronic Supplementary Material.
1. adjacent segment disease
2. spino-pelvic parameters
3. lumbar degeneration
4. sagittal balance
5. pelvic incidence
Take Home Messages
1. Our pooled analysis demonstrated that paƟents whom developed ALD had signiﬁcantly higher
PT, lower SS and PI-LL mismatch prior to fusion and higher PI and postoperaƟve PT compared to
control paƟents without ALD.
2. Although PI-LL has tradiƟonally been considered the index of appropriate surgical correcƟon for
adult deformity, our results implicate that this parameter may be a useful predictor of ALD
following lumbar fusion surgery for degeneraƟve lumbar disease.
3. Given the associaƟon between spinal alignment and the development of ALD, this suggests that
spine surgeons should rouƟnely pay aƩenƟon to spinal alignment in paƟents undergoing surgery
for lumbar degeneraƟve disease, even without overt spinal deformity.
Electronic supplementary material The online version of this
article (https ://doi.org/10.1007/s0058 6-018-5629-6) contains
supplementary material, which is available to authorized users.
Extended author information available on the last page of the article