Failure in Adult Spinal Deformity Surgery

A Comprehensive Review of Current Rates, Mechanisms, and Prevention Strategies

John F. Burke, MD, PhD; Justin K. Scheer, MD; Darryl Lau, MD; Michael M. Safaee, MD; Austin Lui, BS; Sonya Jha, BSc; Chloe Jedwood, BSc; Isabelle Thapar, BSc; Bethany Belfield, BSc; Nami Nobahar, BSc; Albert J. Wang, BS; Elaina J. Wang, BS; Tony Catalan, BS; Diana Chang, BS; Marissa Fury, BS; Patrick Maloney, MD; Henry E. Aryan, MD; Justin S. Smith, MD, PhD; Aaron J. Clark, MD, PhD; Christopher P. Ames, MD

Disclosures

Spine. 2022;47(19):1337-1350. 

In This Article

Abstract and Introduction

Abstract

Study Design: Literature review.

Objective: The aim of this review is to summarize recent literature on adult spinal deformity (ASD) treatment failure as well as prevention strategies for these failure modes.

Summary of Background Data: There is substantial evidence that ASD surgery can provide significant clinical benefits to patients. The volume of ASD surgery is increasing, and significantly more complex procedures are being performed, especially in the aging population with multiple comorbidities. Although there is potential for significant improvements in pain and disability with ASD surgery, these procedures continue to be associated with major complications and even outright failure.

Methods: A systematic search of the PubMed database was performed for articles relevant to failure after ASD surgery. Institutional review board approval was not needed.

Results: Failure and the potential need for revision surgery generally fall into 1 of 4 well-defined phenotypes: clinical failure, radiographic failure, the need for reoperation, and lack of cost-effectiveness. Revision surgery rates remain relatively high, challenging the overall cost-effectiveness of these procedures.

Conclusion: By consolidating the key evidence regarding failure, further research and innovation may be stimulated with the goal of significantly improving the safety and cost-effectiveness of ASD surgery.

Introduction

Adult spinal deformity (ASD) surgery is becoming increasingly prevalent as both life expectancy and functional health expectations of the elderly increase in the United States. As a result, there is increasing academic output from ASD surgeons, which has exponentially risen over the last 10 years (Figure 1). The expanding number of ASD surgeries has created a clinical problem: how can surgeons evaluate and treat the complex failures that can occur after ASD surgery?

Figure 1.

Growth in adult spinal deformity surgery over time. The number of publications with "adult spinal deformity" as keyword is listed as a function of the year of publication. Search terms included English language articles that were original clinical trials or original clinical research (reviews, abstracts, chapters, and meta-analyses were not included).

One of the primary goals of ASD surgery is to achieve global sagittal and coronal alignment with harmonious lumbar lordosis (LL).[1–3] More specifically, it has been shown that spinal fusions achieving sagittal alignment targets of less than ~4.5 cm for sagittal vertical axis and ±10° for pelvic incidence–LL mismatch results may result in significant clinical benefit.[2,4–6] Furthermore, there is a trend toward "harmonious" and physiologic corrections accounting for spinal morphotypes such as planning three-column osteotomies at lower lumbar levels.[7] Such powerful techniques can achieve the desired correction, but are also associated with higher complication rates.[8]

On top of this, there is a recent increased focus on the cost-effectiveness of ASD surgery.[9] Because ASD surgery often requires longer length of stay and time in the intensive care unit,[10] it is associated with a high incremental cost-effectiveness ratio (ICER) that can be further increased by costly reoperations for failures.[10] For the field to be sustainable, reoperation rates for failure must be decreased, especially in the first 10 years from index procedures. However, despite the importance of avoiding failure after ASD surgery and the increasing abundance of ASD literature, there currently exists no comprehensive review summarizing the current failure rates, failure modes, and prevention strategies. In this review, we present well-defined phenotypes of failure in ASD surgery focusing on clinical failure, radiographic failure [pseudarthrosis (PSA), instrumentation failure, proximal junctional kyphosis (PJK)], the need for reoperation, and lack of cost-effectiveness.

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