The Clinical Study On The Effect Of Cage Position And Size On Lumbar Lordosis In Single-segment Posterior Lumbar Fusion

ObjectiveTo investigate the effects of the position and size of Cages on the recovery of lumbar lordosis(LL)after fusion in patients undergoing L4/5 and L5/S1 single-segment TLIF fusion.The clinical curative effect of the degree of recovery of lumbar lordosis after operation was analyzed to provide a certain theoretical basis for clinical treatment.MethodsA retrospective analysis of Department of Orthopaedics,Guangdong Provincial Hospital of Traditional Chinese Medicine,performed L4/5 or L5/S1 due to lumbar degenerative diseases(lumbar disc herniation,lumbar spinal stenosis,mild lumbar spondylolisthesis)from January 2015 to December 2018.Single-segment transforaminal lumbar interbody fusion(TLIF)was performed in a single Cage patient,and a total of 60 patients were selected.By collecting relevant clinical data of preoperative,postoperative and follow-up time nodes,and using VAS,JOA scoring criteria to evaluate the clinical efficacy of the operation,by collecting preoperative,postoperative and 1-year follow-up lumbar spine radiographs,respectively Measure Cage’ s Central Point Ratio(CPR),Posterior Gap Ratio(PGR),Disc Height(DH),Segment Lumbar Lordosis(SLL)Lumbar Lordosis(LL).Record the imaging and clinical data of the patients before,after,and at the last follow-up.Use EXCEL 2007 software to establish a database and use SPSS 18.0 software to perform statistical analysis.Compare the correlations between the indexes before,after,and at the last follow-up.P<0.05 was considered statistically significant.ResultsThe 60 patients included in the study were all followed up by outpatient review after 1 year.The preoperative JOA score of the whole group was 14.98±2.78,the last follow-up was 25.42±1.73,the preoperative VAS score was 5.33±1.65,and the last follow-up was 0.81±0.57.The differences were statistically significant(P<0.05).The angles of SLL before operation,after operation and last follow-up were 7.43±1.51°,13.14 ± 2.05°,13.52±1.63°,respectively.The difference between SLL before operation and SLL after operation and last follow-up were statistically significant(P<0.05).The pre-operative,post-operative and final follow-up angles of LL were 40.40±14.13°,45.70±13.45°,and 46.82±14.73°,respectively.The difference between pre-operative LL and postoperative and final follow-up LL was statistically significant(P<0.05).The sizes of DH before operation,after operation and last follow-up were 0.35 ±0.07,0.52 ± 0.04,0.54 ±0.09 respectively.The difference between DH before operation and DH after operation and last follow-up was statistically significant(P<0.05).CPR and PGR are closely related to SLL changes(r=0.63,r=0.60,P<0.01),CPR and PGR also show close correlations to LL changes(r=0.39,r=0.39,P<0.01),and ΔDH is related to SLL,LL changes showed a negative correlation(r=-0.58,r=-0.37,P<0.01).There was a correlation between the change of SLL and LL and the improvement of JOA score(r=0.38,r=0.65,P<0.05).ConclusionIn the posterior lumbar spine TLIF surgery,the position parameters of Cage in CPR,PGR are positively correlated with the change in LL,so that the Cage is placed properly and slightly larger to increase CPR.PGR and the use of a larger Cage can optimize the change of lumbar lordosis Improve patients’quality of life.