Two-Year Follow-Up of Decompression With or Without Fusion From Degenerative Lumbar Spondylolisthesis Guided By a Novel Radiographic Intervertebral Motion Metric
Joey F.H. Reijmer, Lex D. de Jong, Diederik H.R. Kempen, Mark P. Arts, Marinus de Kleuver, Job L.C. van SusanteStudy Design:
A prospective, multicenter, single-arm clinical study.
Objective:
To explore two-year follow-up clinical outcomes of patients with degenerative lumbar spondylolisthesis, whose surgical planning for decompression with or without fusion was guided by a novel spinal stability metric.
Summary of Background Data:
An objective diagnostic tool is needed to quantify abnormal motion between lumbar vertebrae and to guide surgical decision-making between decompression only or decompression with fusion in patients with lumbar spinal stenosis. Earlier, we reported on the use of a spinal instability metric in surgical decision making, which resulted in a 29% change in intended surgical plans and an 11% decrease in instrumented fusions without a significant impact on clinical outcomes at one-year postoperative. A longer follow-up is important to monitor potential changes in clinical outcomes and reoperations.
Materials and Methods:
Two years of follow-up data were analyzed for 65 participants (51 decompression only and 14 decompression with fusion). Patients were assessed using the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) scores for leg and/or buttock pain and were compared with historical controls. Secondary outcomes included potential reoperations, the prescription of analgesics, patient satisfaction, and adverse events.
Results:
Clinical scores revealed a similar trend in improvements in both groups, with significant improvements in disability related to low back pain and leg and/or buttock pain intensity at two years. These improvements resembled data from historical controls. In the decompression-only group, five patients were converted to fusion at two years. Analgesic use and satisfaction stabilized after six months.
Conclusion:
The use of an instability metric guiding surgical decision making towards decompression with or without fusion was associated with a decrease in instrumented fusions, whereas clinical outcomes overall remained in-line with available literature at two years follow-up. Encountered additional fusions in the decompression only group during follow-up mitigated this original decrease in fusion rate and has to decrease with further evolvement of these automated radiographic instability metrics incorporating, for example, foraminal morphology and disc height. As such, evolved radiographic metrics may play an important role in the future in improved tailoring of surgical planning of lumbar spinal stenosis from degenerative spondylolisthesis.
Level of Evidence:
Level III.