Published in:
01-08-2016 | Original Article
Incidence and risk factors for proximal junctional kyphosis: a meta-analysis
Authors:
Feng-Yu Liu, Tao Wang, Si-Dong Yang, Hui Wang, Da-Long Yang, Wen-Yuan Ding
Published in:
European Spine Journal
|
Issue 8/2016
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Abstract
Purpose
To analyse the incidence and risk factors associated with proximal junctional kyphosis (PJK) following spinal fusion, we collect relative statistics from the articles on PJK and perform a meta-analysis.
Methods
An extensive search of literature was performed in PubMed, Embase, and The Cochrane Library (up to April 2015). The following risk factors were extracted: age at surgery, gender, combined anterior-posterior surgery, use of pedicle screw at top of construct, hybrid instrumentation, thoracoplasty, fusion to sacrum (S1), preoperative thoracic kyphosis angle (T5–T12) >40°, bone mineral density (BMD) and preoperative to postoperative sagittal vertical axis (SVA difference) >5 cm. Data analysis was conducted with RevMan 5.3 and STATA 12.0.
Results
A total of 14 unique studies including 2215 patients were included in the final analyses. The pooled analysis showed that there were significant difference in age at surgery >55 years old (OR 2.19, 95 % CI 1.36–3.53, p = 0.001), fusion to S1 (OR 2.12, 95 % CI 1.57–2.87, p < 0.001), T5–T12 >40° (OR 2.68, 95 % CI 1.73–4.13, p < 0.001), low BMD (OR 2.37, 95 % CI 1.45–3.87, p < 0.001) and SVA difference >5 cm (OR 2.53, 95 % CI 1.24–5.18, p = 0.01). However, there was no significant difference in gender (OR 0.98, 95 % CI 0.74–1.30, p = 0.87), combined anterior-posterior surgery (OR 1.55, 95 % CI 0.98–2.46, p = 0.06), use of pedicle screw at top of construct (OR 1.55, 95 % CI 0.67–3.59, p = 0.30), hybrid instrumentation (OR 1.31, 95 % CI 0.92–1.87, p = 0.13) and thoracoplasty (OR 1.55, 95 % CI 0.89–2.72, p = 0.13). The incidence of PJK following spinal fusion was 30 % (ranged from 17 to 62 %) based on the 14 studies.
Conclusions
The results of our meta-analysis suggest that age at surgery >55 years, fusion to S1, T5–T12 >40°, low BMD and SVA difference >5 cm are risk factors for PJK. However, gender, combined anterior–posterior surgery, use of pedicle screw at top of construct, hybrid instrumentation and thoracoplasty are not associated with PJK.