Risk factors associated with distal junctional kyphosis and failure after surgical management of adult cervical deformity: a systematic review.

STUDY

DESIGN

Systematic review.

OBJECTIVE

To characterize risk factors associated with the development of distal junctional kyphosis and failure. Distal junctional kyphosis (DJK) is a significant complication following surgical treatment for adult cervical deformity (ACD). Recent literature has characterized risk factors for DJK development, but no formal systematic review has summarized the available findings to date.

METHODS

This systematic review included articles using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Web of Science, SCOPUS, and MEDLINE databases were searched from inception until December 1, 2023. Articles were included if they reported risk factors associated with the development of DJK or distal junctional failure (DJF) following ACD.

RESULTS

Thirteen of the 1619 articles met the criteria. Selected studies included 1395 patients, of which 362 developed DJK and/or DJF. The mean age was 60.7 years, and 561 (40.2%) were male. Neurologic symptoms were associated with DJK development (p = 0.012; OR: 3.71). Surgical factors, including number of fusion levels, combined anterior-posterior approach, and use of posterior osteotomies, were correlated with increased rates of DJK (p < 0.01). T1 slope > 45.5 degrees and C2 slope > 38 degrees increased DJF risk (p = 0.014) and reoperation rate (p < 0.001). DJF rates were lower in ACD patients with C2-T2 compared to C3-T1 posterior spinal fusion (1.0% vs. 20%; p < 0.001).

CONCLUSIONS

Demographic factors were rarely associated with DJK. Surgical factors, such as combined approach, posterior osteotomies, and construct termination at T1, were associated with DJK but may be confounded by more rigid deformities. Radiographic factors also correlated with DJK, appearing to align with baseline and corrected sagittal balance severity. Given the high incidence of DJK following correction for ACD, further research is essential to identify causal and modifiable risk factors.