The effect of various options for decompression of degenerated lumbar spine motion segments on the range of motion: a biomechanical in vitro study

Abstract

Background Lumbar spinal stenosis is a common disease in the aging population. Decompression surgery represents the treatment standard, however, a risk of segmental destabilization depending on the approach and extent of decompression is discussed. So far, biomechanical studies on techniques were mainly conducted on non-degenerated specimens. This biomechanical in vitro study aimed to investigate the increase in segmental range of motion (ROM) depending on the extent of decompression in degenerated segments. Methods Ten fresh frozen lumbar specimens were embedded in polymethyl methacrylate (PMMA) and loaded in a spine tester with pure moments of ± 7.5 Nm. The specimens were tested in their intact state for lateral bending (LB), flexion/extension (FE) and axial rotation (AR). Subsequently, four different decompression techniques were performed: unilateral interlaminar decompression (DC1), unilateral with "over the top" decompression (DC2), bilateral interlaminar decompression (DC3) and laminectomy (DC4). The ROM of the index segment was reported as percent (%) of the native state. Results Specimens were measured in their intact state prior to decompression. The mean ROM was defined as 100% (FE:6.3 ± 2.3°; LB:5.4 ± 2.8°; AR:3.0 ± 1.6°). Interventions showed a continuous ROM increase: FE (DC1: + 4% ± 4.3; DC2: + 4% ± 4.5; DC3: + 8% ± 8.3;DC4: + 20% ± 15.9), LB(DC1: + 4% ± 6.0; DC2: + 5% ± 7.3; DC3: + 8% ± 8.3; DC4: + 11% ± 9.9), AR (DC1: + 7% ± 6.0; DC2: + 9% ± 7.9; DC3: + 15% ± 11.5; DC4: + 19% ± 10.5). Significant increases in ROM for all motion directions (p < 0.05) were only obtained after complete laminectomy (DC4). Conclusion Unilateral and/or bilateral decompressive surgery resulted in a statistically insignificant ROM increase, whereas complete laminectomy showed statistically significant ROM increase. If this ROM increase also has an impact on the clinical outcome and how to identify segments at risk for secondary lumbar instability should be evaluated in further studies.

Spinal surgery and the risk of reoperation after total hip arthroplasty: a cohort study based on Swedish spine and hip arthroplasty registers

“…Our cohort, with 84% of the cases having a decompression only as their spinal stenosis surgery, suggests that the prevalence of lumbar spinal stenosis itself constitutes a risk for THA reoperation, possibly through the same mechanisms as in the setting of spinal deformities. In addition, it seems that lumbar spine decompression without fusion at least does not increase the spinal stiffness, supporting the idea that the spinal pathology itself may increase the risk, and not necessarily only the surgical procedure [17,18].…”

Biomechanical response of decompression alone in lower grade lumbar degenerative spondylolisthesis--A finite element analysis

“…Laminectomy is a common surgical method for lumbar stenosis. According to the results of finite element analysis and cadaveric specimen experiments [ 29 , 30 ], unilateral laminectomy had a minimal impact on the segmental ROM. Zander et al conducted finite element analysis by establishing a lumbar spine model to compare the biomechanical effects of graded facetectomy.…”

“…Postacchini et al reported that 3 out of 32 patients suffered from significant segment disability after total laminectomy [ 32 ]. In Lener et al‘s study [ 30 ], when complete laminectomy was performed with bilateral partial facetectomy, segmental ROM increased by 20% ± 15.9, 11% ± 9.9, and 19% ± 10.5% in flexion-extension, lateral bending, and axial rotation, respectively. In our study, due to the preservation of facet joints, the percentage increase in segmental ROM was smaller compared to cadaveric specimen experiments.…”

Effect of two-level decompressive procedures on the biomechanics of the lumbo-sacral spine: an ex vivo study

“…Additionally, they assessed the range of motion of the single motion segment, without assessing any effects on the adjacent segment ( Costa et al, 2018 ). Lener et al (2023) , reported that the intersegmental motion of four-lumbar-vertebrae specimens significantly increased after laminectomy, as opposed to hemilaminectomy. The ROM of the adjacent motion segment was not significantly affected by the amount of decompression ( Lener et al, 2023 ).…”