Comparative Study Of The Effects Of Posterior Lumbar Elastic Fixation And Interbody Fusion On Paraspinal Muscles

Objective: Comparison of posterior K-rod elastic internal fixation with traditional PLIF for the treatment of multifidus muscle injury in degenerative lumbar spine disease,and to explore the factors of secondary degeneration of multifidus muscle and posterior segment degeneration after posterior lumbar spine surgery.The correlation between postoperative residual low back pain and multifidus atrophy and fat infiltration was analyzed.To provide a reference for the clinical treatment of lumbar degenerative diseases when formulating surgical plans and selecting internal fixation.Methods: The clinical and follow-up data of patients who received K-rod elastic internal fixation and PLIF for the treatment of lumbar degenerative diseases in the First Affiliated Hospital of Jinan University from May 2015 to December 2018 were retrospectively analyzed.A total of 52 patients were included in this study,including 27 patients in the K-rod group,21 males and 6 females,with an average age of about 44 years;25 patients in the PLIF group,13 males and 12 females,with an average age of 50 years.By comparing the surgical data,imaging data and clinical efficacy of the two groups of patients,we explored the factors of multifidus muscle degeneration and posterior disc degeneration after posterior lumbar spine surgery.The correlation between postoperative residual low back pain and multifidus atrophy and fat infiltration was analyzed.Results: 1.The operation time,intraoperative blood loss,postoperative drainage volume,postoperative ground movement time and average postoperative hospital stay in the K-rod group were better than those in the PLIF group.2.The treatment effect of the two groups of patients is good.At the last follow-up,the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)were significantly improved compared with those before surgery.3.Range of motion(ROM)of the upper and lower adjacent segments of the two groups of patients did not change significantly compared with that before the operation;the ROM of the surgical segment of the K-rod group remained about 61%.There was no significant change in the height of the intervertebral space between the two groups of patients before and after the operation.4.At the last follow-up,the functional cross-sectional area(FCSA)atrophy,fat infiltration,and Pfirrmann grading of the intervertebral discs in the PLIF group were significantly greater than those in the K-rod group.5.Adjacent segmental multifidus muscle atrophy and fat infiltration were significantly positively correlated with postoperative back pain in both groups.Conclusions: 1.Compared with traditional PLIF surgery,unilateral K-rod elastic internal fixation under the posterior approach has advantages of less trauma,less bleeding,quick postoperative recovery,and less damage to multifidus muscles.It is a safe,reliable,and minimally invasive method with good short-term efficacy.2.There is a significant positive correlation between multifidus atrophy and fat infiltration after posterior lumbar spine surgery and postoperative residual low back pain.