Patients undergoing surgery for lumbar spinal stenosis experience unique courses of pain and disability: A group-based trajectory analysis.

Eden Richardson,Kenneth Thomas ,Najmedden Attabib,Bradley Jacobs,Niels Wedderkopp,Henry Ahn,Edward Abraham,Michael G Johnson ,Parham Rasoulinejad,Hamilton Hall,Alexandra Stratton,Eugene K Wai,Neil Manson,Andrew Nataraj,Peter Jarzem,Mariah Darling ,Charles G Fisher,Jérôme Paquet ,Erin Bigney,Y Raja Rampersaud,Jeffrey J Hébert

doi:10.1371/journal.pone.0224200

Abstract

ObjectiveIdentify patient subgroups defined by trajectories of pain and disability following surgery for degenerative lumbar spinal stenosis, and investigate the construct validity of the subgroups by evaluating for meaningful differences in clinical outcomes.MethodsWe recruited patients with degenerative lumbar spinal stenosis from 13 surgical spine centers who were deemed to be surgical candidates. Study outcomes (leg and back pain numeric rating scales, modified Oswestry disability index) were measured before surgery, and after 3, 12, and 24 months. Group-based trajectory models were developed to identify trajectory subgroups for leg pain, back pain, and pain-related disability. We examined for differences in the proportion of patients achieving minimum clinically important change in pain and disability (30%) and clinical success (50% reduction in disability or Oswestry score ≤22) 12 months from surgery.ResultsData from 548 patients (mean[SD] age = 66.7[9.1] years; 46% female) were included. The models estimated 3 unique trajectories for leg pain (excellent outcome = 14.4%, good outcome = 49.5%, poor outcome = 36.1%), back pain (excellent outcome = 13.1%, good outcome = 45.0%, poor outcome = 41.9%), and disability (excellent outcome = 30.8%, fair outcome = 40.1%, poor outcome = 29.1%). The construct validity of the trajectory subgroups was confirmed by between-trajectory group differences in the proportion of patients meeting thresholds for minimum clinically important change and clinical success after 12 postoperative months (p < .001).ConclusionSubgroups of patients with degenerative lumbar spinal stenosis can be identified by their trajectories of pain and disability following surgery. Although most patients experienced important reductions in pain and disability, 29% to 42% of patients were classified as members of an outcome trajectory subgroup that experienced little to no benefit from surgery. These findings may inform appropriate expectation setting for patients and clinicians and highlight the need for better methods of treatment selection for patients with degenerative lumbar spinal stenosis.

Highlights

Degenerative lumbar spinal stenosis (LSS) is a common musculoskeletal disorder, experienced by 1 in 5 adults 65 years or older [1, 2]
The construct validity of the trajectory subgroups was confirmed by between-trajectory group differences in the proportion of patients meeting thresholds for minimum clinically important change and clinical success after 12 postoperative months (p < .001)
Subgroups of patients with degenerative lumbar spinal stenosis can be identified by their trajectories of pain and disability following surgery

Summary

Introduction

Degenerative lumbar spinal stenosis (LSS) is a common musculoskeletal disorder, experienced by 1 in 5 adults 65 years or older [1, 2]. Surgery for LSS is the most frequent type of spinal surgery performed on older adults and will become increasingly common as the population ages [5]. Consistent with the clinical experiences of many spine surgeons, early clinical evidence for the efficacy [6, 7] and cost-effectiveness [8] of surgery for LSS is promising. Challenges in carrying out randomized trials in surgery persist, as do issues around generalizability and patient selection [3, 9]. Clinicians treating patients with LSS would benefit from expanded evidence to guide decisions around operative and non-operative interventions

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Conclusion