Incidence and risk factors for proximal junctional kyphosis: a meta-analysis
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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.
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.
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.
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.
KeywordsIncidence Risk factors Proximal junctional kyphosis Meta-analysis
Compliance with ethical standards
Conflict of interest
All authors have declared that we have no conflict of interest.
- 4.Cammarata M, Wang X, Mac-Thiong JM, Ce A (2012) Biomechanical analysis of proximal junctional kyphosis: preliminary results. Stud Health Technol Inform 76:299–302Google Scholar
- 9.El-Hawary R, Sturm P, Cahill P, Samdani A, Vitale M, Gabos P et al (2015) What is the risk of developing proximal junctional kyphosis during growth friendly treatments for early-onset scoliosis? J Pediatr Orthop [Epub ahead of print] Google Scholar
- 11.Ha Y, Maruo K, Racine L, Schairer WW, Hu SS, Deviren V et al (2013) Proximal junctional kyphosis and clinical outcomes in adult spinal deformity surgery with fusion from the thoracic spine to the sacrum: a comparison of proximal and distal upper instrumented vertebrae. J Neurosurg Spine 19(3):360–369. doi: 10.3171/2013.5 CrossRefPubMedGoogle Scholar
- 13.Helgeson MD, Shah SA, Newton PO, Clements DH 3rd, Betz RR, Marks MC et al (2010) Evaluation of proximal junctional kyphosis in adolescent idiopathic scoliosis following pedicle screw, hook, or hybrid instrumentation. Spine 35(2):177–181. doi: 10.1097/BRS.0b013e3181c77f8c CrossRefPubMedGoogle Scholar
- 17.Kim HJ, Bridwell KH, Lenke LG, Park MS, Song KS, Piyaskulkaew C et al (2014) Patients with proximal junctional kyphosis requiring revision surgery have higher postoperative lumbar lordosis and larger sagittal balance corrections. Spine 39(9):E576–E580. doi: 10.1097/BRS.0000000000000246 CrossRefPubMedGoogle Scholar
- 22.Kim YJ, Lenke LG, Bridwell KH, Kim J, Cho SK, Cheh G et al (2007) Proximal junctional kyphosis in adolescent idiopathic scoliosis after 3 different types of posterior segmental spinal instrumentation and fusions: incidence and risk factor analysis of 410 cases. Spine 32(24):2731–2738CrossRefPubMedGoogle Scholar
- 23.Lau D, Clark AJ, Scheer JK, Daubs MD, Coe JD, Paonessa KJ et al (2014) Proximal junctional kyphosis and failure after spinal deformity surgery: a systematic review of the literature as a background to classification development. Spine 39(25):2093–2102. doi: 10.1097/BRS.0000000000000627 CrossRefPubMedGoogle Scholar
- 24.Lee JH, Kim JU, Jang JS, Lee SH (2014) Analysis of the incidence and risk factors for the progression of proximal junctional kyphosis following surgical treatment for lumbar degenerative kyphosis: minimum 2-year follow-up. Br J Neurosurg 28(2):252–258. doi: 10.3109/02688697.2013.835369 CrossRefPubMedGoogle Scholar
- 28.Mummaneni PV, Park P, Fu KM, Wang MY, Nguyen S, Lafage V et al (2016) Does minimally invasive percutaneous posterior instrumentation reduce risk of proximal junctional kyphosis in adult spinal deformity surgery? A propensity-matched cohort analysis. Neurosurgery 78(1):101–108. doi: 10.1227/NEU.0000000000001002 CrossRefPubMedGoogle Scholar
- 30.Reames DL, Kasliwal MK, Smith JS, Hamilton DK, Arlet V, Shaffrey CI (2015) Time to development, clinical and radiographic characteristics, and management of proximal junctional kyphosis following adult thoracolumbar instrumented fusion for spinal deformity. J Spinal Disord Tech 28(2):E106–E114. doi: 10.1097/BSD.0000000000000158 CrossRefPubMedGoogle Scholar
- 31.Sacramento-Dominguez C, Vayas-Diez R, Coll-Mesa L, Parrilla AP, Machado-Calvo M, Pinilla JA et al (2009) Reproducibility measuring the angle of proximal junctional kyphosis using the first or the second vertebra above the upper instrumented vertebrae in patients surgically treated for scoliosis. Spine 34(25):2787–2791. doi: 10.1097/BRS.0b013e3181b61955 CrossRefPubMedGoogle Scholar
- 33.Wang Y, Kawakami N, Tsuji T, Ohara T, Suzuki Y, Saito T et al (2015) Proximal junctional kyphosis following posterior hemivertebra resection and short fusion in children younger than 10 years. J Spinal Disord Tech [Epub ahead of print] Google Scholar
- 34.Watanabe K, Uno K, Suzuki T, Kawakami N, Tsuji T, Yanagida H et al (2014) risk factors for proximal junctional kyphosis associated with dual-rod growing-rod surgery for early-onset scoliosis. J Spinal Disord TechGoogle Scholar
- 39.Zhao Y, Li CD, Liu XY, Yi XD, Liu H, Lu HL et al (2013) Analysis of sagittal parameters about senior thoracolumbar proximal junctional kyphosis after lumbar long segment fusion. Beijing da xue xue bao Yi xue ban J Peking Univ Health Sci 45(5):732–737Google Scholar
- 41.Xiao SW, Jiang H, Yang LJ, Xiao ZM (2015) Anterior cervical discectomy versus corpectomy for multilevel cervical spondylotic myelopathy: a meta-analysis. Eur Spine J: Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv Spine Res Soc 24:31–39. doi: 10.1007/s00586-014-3607-1 CrossRefGoogle Scholar