Comparison Study Of The Paraspinal Muscles Changes Between Wiltse Approach And Conventional Approach

Background:The injury of muscle induced by traditional and open lumbar interbody fusion has gained attention. Transforaminal lumbar interbody fusion (TLIF) has been widely used in treating spinal instability or deformity resulting from scoliosis or spondylolisthesis as well as low back pain from degenerative disk disease. Because of extensive dissection and distraction of multifidus, the conventional approach of TLIF causes many complications, such as postoperative flat back syndrome, intractable low back pain, and adjacent segment degeneration. In1968, Wiltse et al first described the paraspinal sacrospinalis muscle-splitting approach to the lumbar spine, named Wiltse approach. The Wiltse approach provided a more direct approach to the transverse processes and pedicles. Unlike the traditional midline incision, it was also thought to reduce the damage of paraspinal muscle. The Wiltse approach has recently been adapted for TLIF.Purpose:To compare the effects of Wiltse Approach on paraspinal muscles with that of Conventional Approach in treating single-level lumbar diseases.Method:In our prospective study, Fourty-seven patients of single-level lumbar diseases who need undergo trans-foraminal lumbar interbody fusion (TLIF) were included. These patients were randomly divided into2groups:Wiltse approach group (25cases) and conventional approach group (22cases). The Visual Analogue Scale/Score (VAS) scores of the3rd day, the14th day and the1st year after operation were accessed. The preoperative and post-operative creatine kinases (CK), as a biomarker of muscle injury, were also measured. MRI scores of the1st year after operation were observed to access the status of muscle infiltrated by fat. Furthermore, pathological changes of multifidus were observed.Results:There were no differences in preoperative VAS scores and CK between two groups (P>0.05). The VAS scores of the3rd day, the14th day and the1st year after operation were lower in wiltse approach group than in conventional approach group. The2rd day-postoperative CK were elevated, however the up-regulation of CK was partly lessened in wiltse approach group compared with that in conventional approach group (P<0.05). MRI scores of the1st year after operation were also lower in wiltse approach group than in conventional approach group (P<0.05). Pathological changes of multifidus in conventional approach group showed atrophy of muscle, formation of scar and deposition of fat between muscle fibers, whereas in wiltse approach group, these conditions were alleviated.Conclusion:The results suggested that Wiltse approach has less negative effect on paraspinal muscles especially on multifidus than conventional approach in treating single-level lumbar diseases. Wiltse approach can protect the multifidus, retain the stability of the spine,lower the incidence rate of the intractable low back pain and improve the quality of patients’life.AS it is easier to bu put into effect, can avoid the destruction of paraspinal muscles and arrive at the target site in short path,it worth to be popularized in clinic practices.