Clinical Significance Of Irregular Alteration Of Facet Orientation In The Lumbar Disc Herniation

Background:Facet joint also was known as Zygapophyseal joint,was the only diarthrodial joint in the spine.It was an important structure in lumbar spine,which carries about 16% vertical load of lumbar spine and it can also increased in some conditions.The lumbar face joint performed complex biomechanical performance in the movement and effects on overall spine behavior and health.The facet joint orientation was an important factor which can influence the segment motion and the stability of the lumbar spine.The association between facet joint orientation and the degeneration of the lumbar disc was a focus issue.Lumbar disc herniation(LDH)is a common reason for lover limb radiation pain in clinical,it is also one of the most common diseases affecting patients ’ quality of life.The possibilities for a person suffer from LDH was about 40% in their lifetime as the literature reported.Factors for the development of LDH is a hot issue.There were many reasons for the development of lumbar disc herniation as the previous reports,such as degeneration of lumbar disc,injury,age and genetic factors.Facet joint orientation plays an important role in the maintenance of stability of lumbar spine,and it has become the focus of clinical research.The three-point structure that was formatted by the two facet joints and the disc,connected the two adjacent vertebral body and transfer the body dress together.So the facet joints may have some relationship with the degenerative lumbar diseases.Facet tropism,which means the asymmetry of joint angle on both sides,was first reported by by Farfan and Sullivan in 1967.They also found that facet tropism was related to annular tear,so they think that facet tropism was associated with the lumbar disc herniation.Ishihara et al also get a familiar conclusion with Farfan.But there was also counterview about the relationship between facet tropism and the development of lumbar disc herniation.A biomechanical study recently showed that facet tropism per se did not increase disc stress or facet joint stress prominently at the corresponding level under four pure moments,but facet tropism could make the corresponding segment more vulnerable to external moments or anterior shear force.All the studies about the facet joint orientation and degenerative lumbar diseases in the previous were focus on a single level facet.The lumbar spine was a whole functional unit,and the facet joint may influence each other between the adjacent segments.Investigation of the association between degenerative lumbar diseases and facet joint orientations in multiple segments may be more meaningful than that in a single level.We found a new facet joint morphological structure that was the included angle of facet joint which did not increase form the L3/4 to L5/S1 as normal did,and we named it as Irregular Alteration of Facet Orientation(IAFO).The biomechanical feature of the IAFO was unclean now,but it may lead to an irregular motion curve in the lumbar spine and may be influence the lumbar disc in some extent.Investigation of the relationship between IAFO and LDH would be a part of work in our study.Percutaneous endoscopic lumbar discectomy(PELD)has became a popular procedure for LDH,there were many advantages in the PELD compared with open discectomy,such as less injury,less bleeding,and sooner recovery.But recurrence of LDH after discectomy without fusion was a problem that the doctor must face up.Many of papers have reported the risk factor for recurrent lumbar disc herniation,such as age,Modic change,smoking and so on.There was no paper about the role of facet joint orientation to the recurrent lumbar disc herniation,as we know.Investigation the role of IAFO in the development of LDH in adolescents and adults,and the role in the recurrence of LDH after PELD would be our interests.Part 1 The Association between irregular alteration of facet orientation and the lumbar disc herniation in adolescents.Purposes: The aim of this study was to investigate the relationship between the irregular alteration of facet orientation(IAFO)and the lumbar disc herniation in adolescent pateints.Metholds: Sixty-five adolescents with lumbar disc herniation were included in the study.Facet angles were measured in magnetic resonance imaging.The IAFO was defined as the irregular orientation of the included facet joints angle,which was regularly increased from L3 to S1 in the normal group,including small-large-small(SLS)type,large-small-large(LSL)type,and large-small-small(LSS)type.Thirty normal adolescents without lumbar lesions were selected into the control group.Statistical analysis was performed using chi-square test.A significance level of 0.05 was adopted.The odds ratio value was used to determine the association of IAFO and LDH.The analysis was performed with SPSS version 13(SPSS,Chicago,Illinois,USA).ReaultsIAFO was observed in 20 of 65 subjects in LDH group compared with 3 of 30 in the control group [P=0.038;OR=4(1.086,14.735)].The SLS type was observed in 14 patients,and the LSL type was found in 6 patients,compared with 2 and 1,respectively,in the control group,no LSS type was found in the two groups.There were 8 subjects with IAFO of SLS style herniated in L5/S1 level compared with 6 subjects in L4/5.There was 1 subject with IAFO of LSL style herniated in L5/S1 level compared with 5 subjects in L4/5.ConclusionsThe findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adolescents.The IAFO maybe a risk factor for the development of lumbar disc herniation in adolescents.Part 2 The association between irregular alteration of facet orientation and the lumbar disc herniation in adults.Purposes:The purposes of this study was to investigate the relationship between the irregular alteration of facet orientation(IAFO)and the lumbar disc herniation in adult patients.MethodsOne hundred and thirty six adults with lumbar disc herniation herniated in L4/5 or L5/S1 were included in the study.Facet angles were measured in magnetic resonance imaging.The IAFO was defined as the irregular orientation of the included facet joints angle,which was regularly increased from L3 to S1 in the normal group,including small-large-small(SLS)type,large-small-large(LSL)type,and large-small-small(LSS)type.Twenty-seven individuals without lumbar lesions were selected into the control group.Statistical analysis was performed using chi-square test.A significance level of 0.05 was adopted.The odds ratio value was used to determine the association of IAFO and LDH.The analysis was performed with SPSS version 13.0(SPSS,Chicago,Illinois,USA).ResultsAFO was observed in 57 of 136 subjects in LDH group compared with 3 of 27 in the control group[P=0.001 OR=5.579(0.600,51.912)].The SLS type was observed in 31 patients,and the LSL type was found in 19 patients,LSS type was 7 patients in the IAFO group.There were 2 SLS type and 1 LSL type were found in the control group,no LSS type was found in the two groups.There were 22 subjects with IAFO of SLS style herniated in L4/5 level compared with 9 subjects in L5/S1.There were 14 subjects with IAFO of LSL style herniated in L4/5 level compared with 5 subjects in L5/S1.One patient with LSS type IAFO herniated in L4/5 and 6 patients herniated in L5/S1.ConclusionsThe findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adults,but the cause-and effect relationship were remain need to be investigated in the future studies.Part3 The clinical significance of Irregular Alteration of Facet Orientation in the recurrence of lumbar disc herniation after percutaneous endoscopic lumbar discectomy.PurposesThe facet orientation was an important factor for the movement of intervertebral segment and keeping stability of the lumbar spine.The purposes of the present study were to investigate the role of irregular alteration of facet orientation in the recurrence of lumbar disc herniation after percutaneous endoscopic lumbar discectomy.MethodsDatas of the patients with single level lumbar disc herniation in L4/5 or L5/S1 who underwent percutaneous endoscopic lumbar discectomy in the department of orthopedics of Xinqiao hospital were collected.Patients were divided into two groups according to their facet angle,irregular alteration of facet orientation group and control group.Observation was performed on the recurrence rate of the two groups through a minimal two years follow-up.ResultsA total of 96 patients were evolved in the study group.Forty-two patients were enrolled in the irregular alteration of facet orientation group and 54 patients were enrolled in the control group.Five patients were re-herniated after percutaneous endoscopic lumbar discectomy after a minimal two years follow-up.There were 4(4/42)patients in the irregular alteration of facet orientation group and 1(1/54)patients in the control group.ConclusionsThe irregular alteration of facet orientation may be a risk factor for the recurrence of LDH.In conclusions1)the findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adolescents.The IAFO maybe a risk factor for the development of lumbar disc herniation in adolescents.2)The findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adults,but the cause-and effect relationship were remain need to be investigated in the future studies.3)Irregular alteration of facet orientation was related to the recurrence of LDH in our study,and the irregular alteration of facet orientation may be a risk factor for the recurrence of LDH.