Post-lumbar discectomy reoperations that are associated with poor clinical and socioeconomic outcomes can be reduced through use of a novel annular closure device: results from a 2-year randomized controlled trial

Abstract

Introduction: Lumbar discectomy patients with large annular defects are at a high risk for reherniation and reoperation, which could be mitigated through the use of an annular closure device (ACD). To identify the most effective treatment pathways for this high-risk population, it is critical to understand the clinical outcomes and socioeconomic costs among reoperated patients as well as the utility of ACD for minimizing reoperation risk.

Methods: This was a post hoc analysis of a prospective, multicenter, randomized controlled trial (RCT) designed to investigate the safety and efficacy of an ACD. All 550 patients (both ACD treated and control) from the RCT with follow-up data through 2 years were included in this analysis (69 reoperated and 481 non-reoperated). Reoperations were defined as any revision surgery of the index level, regardless of indication. Equivalent U.S. Medicare expenditures for reoperations were estimated through cost multipliers derived from the commercially available PearlDiver database.

Results: A significantly greater number of control patients (45/278; 16%) compared to ACD patients (24/272; 9%) underwent a revision surgery at the index level within 2 years of followup (p=0.01). At 2 years of follow-up, the reoperated patients had significantly worse Oswestry Disability Index scores and visual analog scale for leg and back pain scores compared to their non-reoperated counterparts (p<0.0001). The total estimated direct medical costs for reoperation were US $952,348 ($13,802 per reoperated patient), with control patients accounting for the majority of this cost burden ($565,188; 59%).

Conclusion: Post-discectomy reoperation is associated with significantly increased patient morbidity, missed work, and direct treatment costs in a population at high risk for reherniation. Annular closure helped minimize this clinical and socioeconomic burden by reducing the incidence of reoperation by nearly 50% (16% control vs 9% ACD).

Keywords: annular closure device; direct costs; lumbar discectomy; patient-reported outcomes; reherniation; reoperation.

Conflict of interest statement

Disclosure Intrinsic Therapeutics, Inc. provided support for the conduct of the study, analysis of the data, and preparation of this manuscript. PDK, FM, JI, and CT received consulting fees from Intrinsic Therapeutics, Inc. The authors report no other conflicts of interest in this work.

Figures

Figure 1

The Barricaid® annular closure device consists of a titanium anchor, which secures the device into the cranial or caudal vertebral body, and a polymer occlusion component that inserts into the annular defect to retain the nucleus pulposus within the intradiscal space.

Figure 2

The incidence of reoperation is significantly lower among annular closure device (ACD)-treated patients compared with control patients through 2 years. The reoperation rate represents unique patients undergoing at least one reoperation. *p < 0.05; **p ≤ 0.01 by Fisher’s exact test at each time point.

Figure 3

At 2-years of follow-up from the index procedure, the mean Oswestry Disability Index (ODI) (A), visual analog scale (VAS) leg (B), and VAS back (C) scores are significantly greater (worse) in patients who required reoperation (Post Reop) compared with patients who did not require reoperation (No Reop). The mean 36-Item Short-Form General Health Survey (SF-36) Mental Component Summary (MCS) and Physical Component Summary (PCS) scores were significantly lower (worse) in Post Reop patients compared to No Reop patients (D, E). Further stratifying the groups based on treatment demonstrated no significant differences between control and annular closure device (ACD)-treated patients for any of these metrics. ****p<0.0001 by two-way ANOVA. Bars represent mean and error bars represent SD.

Figure 4

Significantly more patients who did not require reoperation (No Reop) experienced clinically significant improvements in Oswestry Disability Index (ODI) (A), visual analog scale (VAS) leg (B), and VAS back (C) scores by 2 years compared to patients who required reoperation (Post-Reop). Clinically significant improvement was defined as a patient experiencing a score improvement of >13 for ODI or 15 for VAS scores as well as reaching a raw score of <25 for ODI, 45 for VAS leg, and 55 for VAS back. *p<0.05, **p<0.01, ***p<0.001, and ****p<0.0001 by Fisher’s exact test.

Figure 5

A significantly greater socioeconomic burden is associated with reoperation. The reoperated patients spent significantly more time in the hospital following severe adverse events (SAEs) (A) and significantly fewer reoperated patients had returned to work by 2 years of post-index surgery (B). ****p<0.0001 by Mann–Whitney test in (A) and by Fisher’s exact test in (B). Bars in (A) represent the mean and error bars are standard error of the mean. Bars in (B) represent the proportion and error bars are the binomial 95% CI.