Patients with predominantly back pain at the time of lumbar fusion for low-grade spondylolisthesis experience similar clinical improvement to patients with predominantly leg pain: mid-term results

BACKGROUND CONTEXT

Patients with back pain predominance (BPP) have traditionally been thought to derive less predictable symptomatic relief from lumbar fusion surgery.

PURPOSE

To compare postoperative clinical outcomes as well as degree of improvement in clinical outcome measures between patients with BPP and patients with leg pain predominance (LPP) undergoing open posterior lumbar fusion.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Analysis of patients who underwent an open posterior lumbar fusion for low-grade (Meyerding Grade I or II) degenerative or isthmic spondylolisthesis from 2011 to 2018 was conducted. Surgery was indicated after failure of conservative treatment to address radiculopathy and/or neurogenic claudication. Patients were excluded if they were under 18 years of age at the time of surgery, had less than 6 months of follow-up, presented with a lumbar vertebral body fracture, tumor, or infection, or underwent a fusion surgery that extended to the thoracic spine, high-grade spondylolisthesis, or concomitant deformity.

OUTCOME MEASURES

Radiographs obtained at preoperative, immediate postoperative, and final visits were evaluated for presence or absence of fusion. Patient-reported outcomes were recorded at preoperative and final clinic visits that included: visual analog scale (VAS) back/leg pain, and Oswestry disability index (ODI). Achievement of minimal clinically important difference (MCID) was analyzed, along with rates of postoperative complication and reoperation.

METHODS

Preoperative and final patient-reported outcomes were obtained. Achievement of MCID was evaluated using following thresholds: ODI 14.9, VAS-back pain 2.1, VAS-leg pain 2.8. For analysis, patients were divided into two groups based on predominant location of pain: predominantly VAS-back pain (BPP) and predominantly VAS-leg pain (LPP).

RESULTS

One hundred forty-one patients met inclusion criteria. Of these, 71 had LPP, and 70 had BPP. Patients with preoperative LPP experienced greater improvements in VAS-leg (p<.001) compared to those with BPP, whereas patients with preoperative BPP experienced greater improvements in VAS-back (p=.011) postoperatively compared to those with LPP. There were no differences in the final clinical outcomes. Additionally, LPP achieved MCID for VAS-leg (p=.027) at significantly higher proportion than BPP and BPP achieved MCID for VAS-back (p=.050) at significantly higher proportion than LPP.

CONCLUSIONS

Patients with low-grade spondylolisthesis who underwent an open posterior lumbar fusion had improvement in symptoms regardless of presentation with BPP or LPP. In properly indicated patients, posterior spinal fusion is effective for those with BPP in the setting of experiencing both leg and back pain, and clinicians can use this information for perioperative discussions and surgical decision-making.