Effectiveness Of Isobar TTL Dynamic System In The Treatment Of Degenerative Lumbar Diseases

BackgroundsLumbar degenerative diseases include a series of lumbar diseases, such as degenerative lumbar spinal stenosis, intervertebral instability, lumbar disc herniation, degenerative lumbar spondylolisthesis and so on. They are frequently-occurring diseases in the field of spine surgery. The clinical manifestations are mainly of lumbocrural pain, lower limbs to be feeling and movement disorders, more serious can appear urine dysfunction and taking the patients with great pain, which seriously influence the patients’ quality of life. The treatments for them include conservative treatment, simple decompression surgery, decompression and fusion with internal fixation. The majority of patients can relieve the symptoms by conservative treatment, but the symptoms often break out repeatedly, some patients will eventually need the surgical treatment.Simple decompression surgery can alleviate the symptoms, but increased the possibility of spinal instability. Decompression and lumbar fusion with internal fixation is the effective treatment of intervertebral instability. It can eliminate the pain by rebuilding the spinal stability, maintaining intervertebral height. It shows satisfactory clinical curative effect for pain relief, and it is the gold standard for the treatment of lumbar degenerative diseases. But its long-term efficacy is not satisfactory. The curative effect was around70%-85%, about3%-14%of the patients need to accept the reoperation. In addition, lumbar activity is obviously limited, motor unit function of the lumbar is lost, biomechanics are changed. These can accelerate adjacent segment degeneration of intervertebral disc in the surgery of the fusion with internal fixation. The surgery of fusion with internal fixation changed the original spinal movement function unit number and the normal spinal biomechanics environment. Stress anomaly concentration on the adjacent segment disc and articular process joint, with promoting the occurrence degeneration, causing acceleration adjacent segment degeneration of intervertebral disc, and so on. Spinal fusion is not the most ideal method for the treatment of lumbar degenerative diseases.In recent years, with the research of the spinal biomechanics and kinematics unceasingly thorough, the researchers found that spinal degeneration will cause abnormal load transmission, which was the main reason for the clinical symptoms and pathological changes of lumbar degenerative diseases. The traditional surgery of lumbar fusion with internal fixation is severely impacted. Restoring normal activities and mechanical transmission of the lumbar has become a new treatment idea, and the concept of non-fusion surgery arised and gradually developed at the historic moment, being the hot spot in the field of spinal surgery. The purpose of non-fusion surgery is to relieve pain and prevent degeneration by limiting lumbar abnormal activities and maintaining normal intervertebral disc load transmission. In addition, it also provides the conditions for the repair of degenerative intervertebral disc. However, there is still controversy that the non-fusion surgery whether can achieve its original design purpose at present. As a new non-fusion device that treatment for lumbar degenerative diseases, the clinical curative effect evaluation of Isobar TTL dynamic internal fixation system is currently the focus in the field of the spine. Isobar TTL dynamic internal fixation system is a kind of device based on the pedicle screws. It can keep part of the spinal motion segment activity and change the load transfer way. It alleviates or eliminates pain of the patients and retains part of lumbar activities, under the premise of the absence of vertebral body fusion. So, it provide us a new method for the treatment of lumbar degenerative diseases. The key part is a unique damping joint. Its internal structure consists of superposition of titanium ring structure and the elastic activity of the damping element is the same as the spinal normal physiological shape, playing the role of shock absorber. Isobar TTL dynamic internal fixation system can be used as single segment of non-fusion or the adjacent segment to the fusion. It reduces stress shelter and maintains intervertebral height and activity, delaying the adjacent segment disc degeneration. This study aims to comprehensive evaluation the clinical curative effect of the non-fusion technology of Isobar TTL dynamic internal fixation system through the retrospective analysis28cases patients of lumbar degenerative diseases from Nan-Fang hospital between November2007and December2010.Objective1. In order to discuss the clinical effect of Isobar TTL dynamic internal fixation system in treatment of lumbar degenerative diseases;2. In order to analysis the imaging results of Isobar TTL dynamic internal fixation system in treatment of lumbar degenerative diseases.MethodsWe make the28patients as the object of the research. They are diagnosed with lumbar degenerative diseases (including lumbar disc herniation, lumbar spinal stenosis disease, degenerative lumbar spondylolisthesis, etc.) from Nan-Fang hospital of southern medical university between November2007and December2010. They are also treated with Isobar TTL dynamic internal fixation system and be followed. We eliminate the patients of incomplete information and the patients who had lumbar surgeries. We find the standards medical record materials of the patients through medical record retrieval system and electronic medical record system of the Nan-Fang hospital and collect X-rays and MRI imagings of the patients from the JW-PACS system.Surgical method:patients were taken prone position after endotracheal intubation anesthesia, making abdominal impending and maintaining lumbar neutral position or mild protruding position. Then we disinfected in the operation area skin with iodine and alcohol, taking conventional disinfection shop towel. Posterior midline incision in the skin, subcutaneous tissue and the deep fascia was taken to expose the bilateral lamina, articular process and transverse process base. According to the standard needle position into the pedicle screw placement respectively, the position of the screw from C-arm machine is exact, then remove of the intervertebral disc which segment need to fusion. After testing the mold in the vertebral clearance, we implanted the appropriate size Cage. Intervertebral disc was retained on the adjacent pathological intervertebral disc section, using the Isobar TTL dynamic internal fixation to protection. C-arm machine was used again, then appropriate pressure on the vertebral clearance, locking nut. After observation implants position, flushing with physiological saline and checking no active bleeding, we placed drainage tube in the incision and suture each layer organization.The final follow-up used the telephone revisit, the letter revisit, the outpatient service reexamination revisit, visit the way revisit and the questionnaire survey form inquiry. All the revisit patients filled in the revisit survey form. Oswestry disability index score (ODI), visual analogue scale (VAS) and Japanese orthopaedic surgeons pain (JOA) score were used to evaluate the postoperative clinical effect of the patients. In addition, we also used Greenough standard to evaluate the clinical effect. All Patients underwent standard Lumbar X-rays In antero-posterior, lateral projections, dynamic flexion and extension and MRI imagings. The changes of intervertebral heights, fusion, lumbar curvature, adjacent segment degeneration and so on were observed according to UCLA (University of California at Los Angeles Grading Scale). The improvement of intervertebral disc degeneration of the dynamic fixed segment in MRI imagings was evaluated according to Pfirrmann grading system. The imageology material’s parameter were measured two times through the JW-PACS system of Nan-Fang hospital, and average value Was taken, precisely to0.01mm or0.01°.The clinical and radiographic data were completed statistical processing by SPSS13.0software. Preoperatively and at the last follow-up of ODI dysfunction index, the VAS pain score and JOA score were completed by paired sample t test, a=0.05; Preoperative and follow-up dynamic fixed at the end of the segmental lumbar motion was processed by paired samples t test, a=0.05; Repeated measures design analysis of variance were used respectively in preoperative, postoperative and follow-up sessions at the end of the intervertebral disc height and the height of the intervertebral foramen, a<0.05prompts statistically significant difference. Preoperative and at the last follow-up for the statistical analysis of degree of intervertebral disc degeneration were processed by paired t test. P<0.05prompts difference of statistically significant.ResultsA total of43patients were included in this study from the November2007to December2010in our department database access, there are28patients in the last follow-up, and the follow-up rate was65.1%. There are18male and10female; Age is from31years old to72years old, the mean age is48years. Among them,9cases of lumbar disc herniation,7cases of lumbar spinal stenosis disease,1case of lumbar olisthe disease,11cases of lumbar disc herniation and spinal canal stenosis. Fusion surgery fixed segments:single segmental fusion24cases, double segmental fusion1case,3cases of no fusion surgery; Dynamic fixed segments:6cases of L3/4,22cases of L4/5. Operation time of the patients is100-345min, with an average of200min; Average intraoperative hemorrhage is from100ml to900ml, with an average of366ml. Follow-up time is15-52months, with an average of35months. Up to the final follow-up, there was no peeling of internal fixation, fracture and related complications.Lumbocrural pain symptoms of the patients were improved significantly after surgery, with the results of better quality of life. The preoperative Oswestry disability index is45.36%±0.18%, at the time of the last follow-up is14.57%±10.17%(P=0.000). The improved rate was64.28%±27.84%. VAS pain score was7.57±0.96points preoperatively, at the time of the last follow-up was1.39±1.07points (P=0.000). JOA score was7.71±4.51points preoperatively, at the time of the last follow-up was22.79±3.08points (P=0.000). The improved rate was69.82%±15.71%. According to Greenough standard:3cases were excellent,16cases were good,8cases were general and1case was poor. The excellent and good rate was67.9%.Up to the final follow-up, there no looseness or breakage of the internal fixation and other related complications was observed. There was no obvious secondary narrow intervertebral disc, vertebral hyperplasia and endplate sclerosis of the dynamic fixed segments according to the UCLA standard. All the fusion was successful at the fusion segments. All the28patients achieved the strong fusion according to the Suk standard of the fusion and the fusion rate was100%.Postoperative lumbar function changed littler, and the lumbar motion is good. The ROM was3.87°±1.73°preoperatively and2.51°±1.31°at the last follow-up. There was no obvious change compared with preoperatively (P=0.241). There are significant differences (P=0.007and P=0.004) of the Anterior disc height of the final follow-up compared with preoperatively and postoperatively. But no significant differences was found in the middle disc height, posterior disc height, Intervertebral foramen height and width among preoperatively, postoperatively and the final follow-up.All patients were taken the lumbar MRI examination before operation and the last follow-up. We evaluated the degree of intervertebral disc degeneration of the dynamic protection segment according to the improvement Pfirrmann grading system and compared with preoperatively. The last follow-up MRI results suggest that there are no disc degeneration progress in18patients compared with preoperatively,5cases from preoperative Pfirrmann grade4to grade3,1case changed from grade4to grade2,1case changed from grade2to grade1,2cases changed from grade3to grade2and only1case changed from grade3to grade4.Conclusion1. The clinical effect of the application of Isobar TTL dynamic internal fixation system for treatment of lumbar degenerative diseases is satisfied.2. It is strong fusion in the fusion segments and protects effectively the disc of the dynamic fixed segment by the Isobar TTL dynamic internal fixation system in the treatment of lumbar degenerative diseases.