A quantitative review of finite element-based biomechanics of lumbar decompression surgery

Lumbar decompression surgeries are commonly performed in the USA to treat pain from spinal stenosis, often with little to no biomechanical evidence to evaluate the risks and benefits of a given surgery. Finite element models of lumbar spinal decompression surgeries attempt to elucidate the biomechanical benefits and risks of these procedures. Each published finite element model uses a unique subset of lumbar decompression surgeries, a unique human lumbar spine, and unique model inputs. Thus, drawing conclusions about biomechanical changes and biomechanical complications due to surgical variations is difficult. This quantitative review performed an analysis on the stresses, forces, and range of motion reported in lumbar spine finite element models that focus on spinal decompression surgeries. To accomplish this analysis, data from finite elements models of lumbar decompression surgeries published between 2000 and December 2023 were normalized to the intact spine and compared. This analysis indicated that increased bony resection and increased ligament resection are associated with increased pathologic range of motion compared to limited resection techniques. Further, a few individual studies show an increase in important outcomes such IVD stresses, pars interarticularis stresses, and facet joint forces due to decompression surgery, but the small number of published models with these results limits the generalizability of these findings to the general population. Future FE models should report these spinal stresses and incorporate patient-specific anatomical features such as IVD health, facet geometry, stenosis patient vertebrae, and vertebral porosity into the model.