The surgical treatment of patients with lumbar spine collapse and slippage is still more controversial. From January 1997 to October 1999, a total of 25 such patients were admitted to our department, and the retrospective analysis is reported as follows. I. Clinical data of patients with lumbar isthmus rupture and slippage Among the 25 patients, 12 were male and 13 were female, aged 17-60 years (average about 42 years). The clinical manifestations included: intermittent claudication, simple persistent low back pain, low back pain with unilateral lower extremity symptoms, and bilateral lower extremity symptoms; lower extremity symptoms were mainly manifested as soreness, discomfort, numbness or pain at rest or during walking, and only one case showed reduced dorsiflexion of the bunion. Most of the symptoms were confined to the buttocks or posterior thighs or knees, involving the calf foot was rare, knee tendon and Achilles tendon reflexes, urination and defecation were normal. There was a clear history of trauma in 3 cases, including 2 cases of sprain and 1 case of smash. The duration of the disease ranged from 5 months to 26 years, with most being 1 to 3 years. Second, the imaging data routine lumbar frontal and lateral and double oblique radiographs showed that there was an isthmic fracture of the vertebral arch, 1 case in L3, 12 cases in L4, and 14 cases in L5, including 2 cases of double-segmental disintegration. CT scan was performed in 18 cases, 12 cases had disc bulge, 2 cases showed lateral-posterior type protrusion and nerve root compression, one of which was consistent with clinical nerve root symptoms. Third, the surgical method: 3 cases of pure bone graft fusion, 22 cases of fusion by self-developed adjustable suspension and repositioning fixator, 2 of which were performed at the same time with interlaminar openings for nucleus pulposus removal. The surgery was performed in prone position under local anesthesia or continuous epidural anesthesia. The lumbosacral spine was routinely exposed posteriorly, and four pedicle screws were screwed into the slipped vertebra and the inferior vertebral body respectively according to the RoyCamille pedicle nail positioning method to thoroughly remove the fibrous connective tissue in the isthmus dissection area, and then the slipped vertebral body was repositioned by upper rod lifting and post-fixation. The iliac bone was taken and implanted in the isthmus crack between the small joint and the transverse process, drainage was placed, the incision was sutured, and the plaster pants were fixed for 3~4 months after removal of stitches. IV. Treatment results Follow-up 10~24 months, average 15 months, 20 cases of complete reset, 2 cases of partial reset, 3 cases of no reset (simple bone graft fusion), the time of bone graft fusion is about 4~6 months. V. Discussion 1. The value of reset Whether lumbar spine collapse and slippage needs to be reset is still controversial. Scholars who do not advocate repositioning believe that repositioning surgery has many complications and is much more dangerous than in situ fusion, so it should not be performed easily. With the development of transforaminal internal fixation devices, most scholars advocate surgical resurfacing. First of all, let us analyze the pathology of collapse and slippage (L5 as an example), the L5 isthmus is divided into two parts after collapse, when standing, especially when weight-bearing, the lumbosacral joint is subjected to a forward and downward slippage force, under the action of the slippage force, the anterior part of L5 slides forward and down along the slope of the posterior superior end of S1 vertebral body, the result of which is that the posterior superior edge of S1 vertebral body and the anterior inferior edge of L5 neural arch trap the cauda equina nerve, while the isthmus Therefore, the repositioning can not only restore the normal shape and volume of the lumbosacral spinal canal and the normal negative gravity line, but also release the compression of the cauda equina nerve and eliminate the symptoms of the lower limbs. In addition, fusion after repositioning can greatly improve the fusion rate. There are also reports of pseudarthrosis formation, the incidence of which is 0%-6%. However, in situ fusion can also cause neurological complications, as Schoenecker found a 6% incidence of cauda equina syndrome after in situ fusion. The Society for the Study of Scoliosis emphasizes that the neurological complications of in situ posterior fusion are the same as those of repositioned fusion. Also the rate of progression of slippage after in situ fusion is as high as 11% to 70%. Therefore, we agree with most experts who advocate repositioning as much as possible but not forcing it. In our group of cases, no adverse complications were seen after repositioning. Individual patients showed symptoms of numbness in the healthy limb after surgery, but they all disappeared within 1~3 months. 2. Regarding the need for decompression, it is controversial whether nerve root decompression is needed for mild lumbar spondylolisthesis. First of all, we understand that the purpose of decompression is to eliminate the radicular neurological symptoms of the lower extremity, and whether decompression is needed should depend on the pathological basis of the lower extremity symptoms. The cause of radicular neuralgia in patients with lumbar isthmus disintegration and slippage is usually due to abnormal activity that stretches the nerve roots or stenosis of the intervertebral foramen caused by fibrocartilage scabs formed at the isthmus, or compression of the nerve roots or cauda equina due to spinal stenosis caused by slippage. Theoretically, the above symptoms can be eliminated by intraoperative removal of the hyperplastic tissue from the cleft and simultaneous repositioning and fixation of the bone graft fusion. The efficacy of this group of cases also verifies the above view. Secondly, it is necessary to distinguish whether the radicular nerve symptoms in the lower extremity are caused by the lumbar isthmus cracking and slipping or by lumbar disc herniation. Pain due to lumbar spine disintegration and slippage radiating to the buttocks or the back of the thigh is common and rarely exceeds the knee joint, which may be due to the stimulation of the posterior branch of the crestal nerve, and it is rare to see the real radiation along the sciatic nerve to the lower leg. The clinical manifestations of nerve root compression in the next plane are different. Only two cases in this group had a definite disc herniation in combination, which is consistent with the above view. The literature reports that the incidence of combined disc herniation ranges from 4% to 27%. In our group, one of the two cases of disc herniation was a disintegrated slipped L5 isthmus combined with herniated L4 and 5 discs. We believe that the reason for such a large difference in the incidence of disc herniation with disintegration is the difference in understanding of the concept of disc herniation and the inconsistency in diagnostic criteria among different authors, and that the CT images often show overlapping images at the level of the slipped disc due to the thick layers, which may appear as images of disc herniation or spinal stenosis, resulting in misdiagnosis. Therefore, we believe that decompression should be strictly indicated and should not be routine, and that decompression is necessary only in patients with clear clinical symptoms and imaging evidence of disc herniation, lateral saphenous stenosis, or severe slippage.