Recurrent Proximal Junctional Kyphosis: Incidence, Risk Factors, Revision Rates, and Outcomes at 2-Year Minimum Follow-up.

Abstract

Study design

Retrospective comparative cohort study.

Objective

Assess the incidence, risk factors, and outcomes of recurrent proximal junctional kyphosis (r-PJK) in PJK revision patients.

Summary of background data

Several studies have identified the incidence and risk factors for PJK after primary surgery. However, few studies have reported on PJK recurrence after revision for PJK.

Methods

A multicenter database of patients who underwent PJK revision surgery with minimum 2-year follow-up was analyzed. Demographic, operative, and radiographic outcomes were compared in patients with r-PJK and patients without recurrence no-Proximal Junctional Kyphosis (n-PJK). Postoperative Scoliosis Research Society-22r, Short Form-36, and Oswestry Disability Index were compared. Preoperative and most recent spinopelvic, cervical, and cervicothoracic radiographic parameters were compared. Univariate and multivariate analyses were used to determine r-PJK risk factors. A predictive model was formulated based on our logistic regression analysis.

Results

A total of 70 patients met the inclusion criteria with an average follow-up of 21.8 months. The mean age was 66.3 ± 9.4 and 80% of patients were women. Before revision, patients had a proximal junctional angle angle of -31.7° ± 15.9°. The rate of recurrent PJK was 44.3%. Logistic regression showed that pre-revision thoracic pelvic angle (odds ratio [OR]: 1.060 95% confidence interval [CI] 1.002; 1.121; P = 0.042) and prerevision C2-T3 sagittal vertical axis (SVA; OR: 1.040 95% CI [1.007; 1.073] P = 0.016) were independent predictors of r-PJK. Classification with these parameters yielded an accuracy of 72.7%, precision of 80.6%, and recall of 73.5%. When examining correction, or change in alignment with revision surgery, we found that change in SVA (OR: 0.981 95% CI [0.968; 0.994] P = 0.005) was the only predictor of r-PJK with accuracy of 66.7%, precision of 74.2%, and recall of 69.7%.

Conclusion

Patients after PJK revision surgery had a recurrence rate of 44%. Logistic regression based on the prerevision variables showed that prerevision thoracic pelvic angle and prerevision C2-T3 SVA were independent predictors of r-PJK.

Level of evidence

4.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1097/brs.0000000000003202

Publication Info

Kim, Han Jo, Shan-Jin Wang, Renaud Lafage, Sravisht Iyer, Christopher Shaffrey, Gregory Mundis, Richard Hostin, Douglas Burton, et al. (2020). Recurrent Proximal Junctional Kyphosis: Incidence, Risk Factors, Revision Rates, and Outcomes at 2-Year Minimum Follow-up. Spine, 45(1). pp. E18–E24. 10.1097/brs.0000000000003202 Retrieved from https://hdl.handle.net/10161/28172.

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Scholars@Duke

Shaffrey

Christopher Ignatius Shaffrey

Professor of Orthopaedic Surgery

I have more than 25 years of experience treating patients of all ages with spinal disorders. I have had an interest in the management of spinal disorders since starting my medical education. I performed residencies in both orthopaedic surgery and neurosurgery to gain a comprehensive understanding of the entire range of spinal disorders. My goal has been to find innovative ways to manage the range of spinal conditions, straightforward to complex. I have a focus on managing patients with complex spinal disorders. My patient evaluation and management philosophy is to provide engaged, compassionate care that focuses on providing the simplest and least aggressive treatment option for a particular condition. In many cases, non-operative treatment options exist to improve a patient’s symptoms. I have been actively engaged in clinical research to find the best ways to manage spinal disorders in order to achieve better results with fewer complications.


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