Clinical Study On MIDLF For Lumbar Degenerative Diseases

Objective1.To evaluate the short term clinical effect of MIDLF in the treatment of lumbar degenerative disease.2.Clinical and radiological comparison between MIDLF and TLIF for lumbar degenerative diseases.Methods1.Twenty patients who received MIDLF surgery were enrolled into this study from May 2016 to May 2018.There were 6 males and 14 females in this group,with an average age of 63.35±7.29 years（from 49 to 76 years）and average BMI 21.22±1.89Kg/m².There were 9 cases of spinal stenosis,5 cases of lumbar degenerative spondylolisthesis and 6 cases of lumbar disc herniation in this group.Fusion levels were all located in the lower lumbar spine（L3-S1）with 14 cases for single and 6 cases for double.Operation duration,blood loss,amount of post-operation drainage,postoperative bedridden time,postoperative hospitalization duration and complications were all recorded.The follow-up time was at least 12 months.Oswestry disability index（ODI）and visual analogue scale（VAS）scores were used to assess the clinical efficacy.Bridwell classification was used to evaluate the fusion.2.From Oct 2017 to Feb 2019,a total of 92 patients who underwent MIDLF or TLIF surgery were retrospectively analyzed,including 35 cases for MIDLF group and 57 cases for TLIF group.Operation duration,blood loss,CK,amount of post-operation drainage,postoperative bedridden time,postoperative hospitalization duration,ODI and VAS scores,complication rate and fusion rate were compared between MIDLF and TLIF group.Results1.All patients underwent MIDLF surgery successfully.The mean operation time was172.00±25.73min（162.07±17.65min for single segment and 195.17±28.02min for double segment）and the mean blood loss was 213.50±48.70ml（191.43±38.80ml for single segment and 265.00±23.45ml for double segment）.The average amount of post-operation drainage was 236.40±58.36m L.The postoperative bedridden time was3.05±0.83d and 6.35±0.81d for postoperative hospitalization duration.VAS scores for low back pain,VAS scores for leg pain and ODI at postoperative 12 months were lower than those at preoperative,and the differences were statistically significant（p<0.05）.According to Bridwell classification,I-II Fusions were observed by radiography for all the patients.No intraoperative complications such as dural tear,nerve injury and postoperative complications such as screw loosening and rupture,cage displacement and sedimentation occurred during follow-up.2.There was no statistical difference between two groups in sex ratio,age,BMI,diagnosis,and surgical segments.Operation duration（168.34±15.98min VS181.63±19.82 min）,postoperative bedridden time（3.14±0.88d VS 3.91±0.71d）and postoperative hospitalization duration（6.34±0.97d VS 7.77±1.39d）were found significantly shorter in the MIDLF group（P<0.05）.The blood loss（223.14±46.00ml VS305.61±65.13ml,p<0.01）,CK at 1^st day after surgery（288.20±47.13U/L VS351.32±76.23U/L,p<0.01）,amount of post-operation drainage（264.31±85.53ml VS290.26±73.37ml,p<0.05）were also lower in MIDLF group.Both groups had significant improvements in the ODI and VAS scores at 6m,12m and last follow up,but no significant difference was found between the two groups.The complication rate was5.7%（2/35）in MIDLF group and 7.0%（4/57）in TLIF group,but no statistical difference was found（p>0.05）.Comparable fusion rates of both groups were also observed by radiography.Conclusions1.MIDLF surgery is safe and reliable in the treatment of lumbar degenerative diseases with good clinical results.MIDLF has the advantages of shorter surgical time and less intraoperative blood loss.2.Both TLIF and MIDLF can achieve good clinical results in the treatment of lumbar degenerative diseases.Compared with the TLIF surgery,MIDLF has the advantages of shorter surgical time,less blood loss,less surgical trauma and faster postoperative recovery.3.The study confirmed the safety and effectiveness of MIDLF in the treatment of lumbar degenerative diseases,demonstrated the advantages over traditional TLIF surgery and summarized the clinical experience of this novel posterior approach related surgery in the treatment of lumbar degenerative disease.