Effects Of Internal Instrumentation Removal On Quality Of Life After Lumbar Spinal Fusion

Background:Lumbar spinal fusion and instrumentation surgery is standard for lumbar degenerative diseases.In patients with lumbar fusion and internal fixation,the necessity to remove the internal fixation device after well bone healing is still a controversial issue.There are still no guidelines to follow regarding this medical procedure,and the relevant factors that affect the quality of life of this patient population are still unclear,so clinicians can only make decisions through subjective experience.After surgery,there is also a lack of objective scientific tools to measure the clinical significance of the patient's surgery.Objectives:This study intends to investigate the necessity of lumbar instrumentation removal surgery and the corresponding influencing factors through a case-control study,with the life quality of patients as the leading observational index and patients who obtained good intervertebral fusion as the observational target.Calculate the optimal minimum clinically important difference(MCID).Methods:Patients who received posterior lumbar decompression and intervertebral fusion and instrumentation for lumbar degenerative diseases and had undergone fixation removal were included in the hardware removal group.Patients with similar statistical characteristics were selected as the control group according to the inclusion criteria.Demographic information,surgical information,and SF-36 quality of Life scale patients were collected.Minimal clinically important difference(MCID)is the minimum that the patient scale score changes enough to achieve clinical significance.MCID was calculated using the health transition Index(HTI)of the SF-36 scale and patient satisfaction as anchors.Four criteria include average change method,change difference method,minimum detectable change value(MDC)method and receiver operating Characteristic Curve method.EXCEL software was used to establish the database,and Graphpad Prism 9.0 software was used for statistical analysis.Kolmogorov-Smirnov method was used to verify the normality.The Man-Whitney test,the paired sample t-test,the rank-sum test and the analysis of variance were selected depending on the data type and normality.In the single factor correlation,the Pearson correlation test and the Spearman correlation test were chosen depending on the data type and whether normality.Results:1.There were 52 patients in the hardware removal group,including 38(73.1%)males.24 patients(46.2%)had lumbar or lower limb symptoms before surgery,6 patients improved,and 1 patient deteriorated after surgery.28 patients(53.8%)did not complain of obvious discomfort before surgery,2 patients improved,and 2 patients became worse after surgery.Under HTI anchor,MCID calculated by mean change method,change difference method,MDC method,and ROC curve method were 3.23,2.24.7.64,and 0.69,respectively.Under the satisfaction anchor,the MCID values calculated by the four methods were 11.38,10.60,12.39,and 0.69,respectively.2.There was no significant difference in demographic characteristics and surgical data between the two groups.The baseline life quality scores of patients in the hardware removal group were significantly lower than those of the control group(83.37±9.25 vs 86.30±13.95,P<0.05).The life quality scores of patients after removal of instrumentation were significantly higher than those before surgery(85.77±9.31 vs 83.37±9.25,P<0.05).After the removal surgery,the life quality score of the hardware removal group was lower than that of the control group,but the difference was not statistically significant(85.77±9.31 vs 86.30±13.95,P=0.0616).There was no statistical correlation between age,length of time between surgeries and the SF-36 scores in the hardware removal group.There was no statistical correlation between the body mass index(BMI)and SF-36 scores except for the emotional function item.There was no significant difference between patients after being grouped by gender,marital status,number of segments,and occupational status.There was no significant difference between patients smoking or not in SF-36 scores,except for the physical function item,which is lower in the smoking group.Conclusions:1.The optimal MCID value calculated with HTI and satisfaction as the anchors are both 0.69.After removing the instrumentation,the score of the SF-36 scale increased by more than 0.69,indicating that the patient's health status was reasonably improved and the patient was satisfied with the surgical results.2.Removal of the hardware can improve the quality of life in patients with discomfort after fusion and instrumentation;however,removal operation may lead to deterioration in patients with no apparent discomfort,so it should not be routinely recommended.