| Lumbar spinal stenosis(LSS) is a common disease in the elderly population, posterior lumbar fusion is usually applied in surgical treatment. Clinical studies have confirmed that posterior lumbar fusion is effective for LSS. However, the complications of this operation also attracts attention, adjacent segment degeneration(ASD) is one of the most serious complications after lumbar fusion. The pathogenesis of ASD and its relevant factors are still under study. In recent years, many researchers have conducted the nonfusion technology in the treatment of LSS to reduce the occurrence of ASD, interspinous dynamic tabilization system Coflex is one of them. At present, this kind of nonfusion instrument has been applied to clinical use and obtained some successful results during the short-term follow-up. But, the Mid-term and long-term effectiveness of Coflex and the effect of postponing ASD is still unclear.Part I. Mid-term clinical outcomes of interspinous dynamic tabilization system Coflex in treatment for lumbar spinal stenosisObjective: To evaluate the mid-term clinical results of interspinous dynamic stabilization system Coflex for lumbar spinal stenosis, and to explore the the effect on ASD.Methods: From October 2008 to December 2013, 38 patients of lumbar spinal stenosis with interspinous dynamic stabilization system Coflex treatment were collected. 19 males and 19 females, average age was 62.1, 20 patients were treated with vertebral lamina windowing decompression and 18 patients were treated with vertebral lamina windowing decompression and discectomy. At preoperation, 3 months postoperation and final follow-up, visual analogue scale(VAS) scores, Japanese Orthopedic Association(JOA) scores and Oswestry disability index(ODI) scores were measured and analyzed to assess clinical efficacy. Lumbar anteroposterior, lateral and flexion-extension X-ray films preoperatively and follow-up were used to measure the following parameters: the range of motion(ROM), the intervertebral space, and the sliding distance of vertebral body. The UCLA grading scale was introduced to evaluate the ASD after the operation.Results: Mean follow-up time was 44.5 months(24 to 67 months), all the patients had symptomatic relief after coflex surgery. The VAS score, JOA score and ODI score 3 months after surgery and at final follow-up were significantly improved compared to those before surgery(P<0.05). four patients got complications including superficial wound infection in 1 patient, Coflex loosening in 1 patient, symptom recurrence in 2 patients and 1 patient received revision surgery. At final follow-up, the ROM of the operated segment were decreased when compared with the preoperative date(P<0.05), the ROM of the adjacent segment have no statistical difference with the preoperative date(P>0.05). At final follow-up, the intervertebral space of the 18 cases who were treated with discectomy was lower than the preoperation(P<0.05), while there was no statistical difference in 20 cases with decompression(P>0.05). There was no statistical difference(P>0.05) existed in the intervertebral space of the adjacent segment. There was no statistical difference(P>0.05) existed in the the sliding distance of vertebral body of the adjacent segment between preoperation and final follow-up. The occurrence rate of r ASD was 7.9%, and there was no c ASD case.Conclusions: The mid-term effectiveness of Coflex is reliable in treatment of LSS. The ROM of the operated segment is decreased with Coflex device implanted, the ROM and the intervertebral space and the sliding distance of vertebral body of the the adjacent segment are not affected after Coflex device implanted, the occurrence rates of ASD is low.Part II Coflex and fusion in treatment of lumbar spinal stenosis: a comparison of effectiveness and the influence on preventing ASDObjective: To evaluate the mid-term clinical value of Coflex in treatment of single-level LSS and the effect on preventing adjacent segment degeneration by comparison of posterior lumbar interbody fusion.Methods: From October 2008 to December 2013, 42 patients of single-level LSS with Coflex surgery treatment and posterior lumbar interbody fusion treatment were collected, and they were divided into Coflex group and fusion group. 20 patients in Coflex group, 12 males and 8 females, average age was 56.8. 22 patients in fusion group, 13 males and 8 females, average age was 59.3, All the patients were evaluated the clinical effect by VAS and ODI before the surgery and at the last follow-up. Preoperation and the finally follow-up, ROM and intervertebral space of adjacent segments were measured by the X-ray films, and the adjacent segment disc degeneration were classified by modified Pfirrmann grading system, that were used to evaluate the occurrence of ASD.Results: Coflex group and fusion group were matched in the gender, age, and length of follow-up. The VAS scores and ODI scores were significantly improved at last follow-up in both groups(P<0.05), and there was no significant difference between two groups(P>0.05). At the last follow-up, ROM of the L3-4 segments in fusion group significantly increased compared to those before surgery(P<0.05), while there was no significant difference in Coflex group(P>0.05). The average value of adjacent segment mean disk height were decreased, however there was no significant difference in two groups(P>0.05). The grade of modified Pfirrmann of adjacent segment intervertebral disc degeneration was increased in 4 case of Coflex group, the occurrence rate of r ASD was 20.0%, while the grade was increased in 10 case of fusion group, the occurrence rate of r ASD was 45.5%. There was no c ASD case in both groups.Conclusions: Coflex in treatment of lumbar spinal stenosis is as effective as fusion surgery in the mid-term follow-up. Coflex has some positive effect on preventing ASD. |
