BackgroundOne of the characteristics of lumbar spinal stenosis (LSS) is elastin degradation and fibrosis in the ligamentum flavum (LF). However, the biochemical factors that cause these histologic changes is unclear. P16 and S100 participate in scar formation and collagen development in wound healing and fibrosis diseases. In this study, we investigate the association between P16 and S100 expression and the fibrosis of the hypertrophic LF in LSS.MethodsThe LF specimens were surgically obtained from 30 patients with single-segment LSS (SLSS), 30 patients with double-segment LSS (DLSS) and 30 patients with L4/5 lumbar disc herniation (LDH). The LF thickness was measured by axial T1-weighted MRI. The extent of LF elastin degradation and fibrosis were graded based on hematoxylin-eosin (HE) and Verhoff’s Van Gieson’s (VVG) stain, respectively. The localization of P16 and S100 was determined by immunohistochemistry.ResultsThe Absolute and relative LF thickness were greater in the DLSS group compared with the SLSS and LDH groups (p <  0.05). The elastic tissue from the dorsal aspect to the dural aspect in SLSS and DLSS groups was significantly increased. The amount of collagen deposition and elastic tissue is significantly higher in the DLSS group compared with the SLSS and LDH groups (p <  0.05). The specimens in the DLSS group showed positive staining of P16, especially in the dorsal layer. Almost all samples in the SLSS group were partially positive for P16. The LDH group showed negative staining of P16 in both the dural and dorsal layers. All the three groups were stained with S100 in the dorsal layer of the LF. On the contrary, S100 staining was absent in the dural layer of the LF in the three groups.ConclusionsElastin degradation and fibrosis of the LF in the DLSS patients is more severe compared with the SLSS and LDH patients. Increased expression of P16 associated with LF fibrosis and thickness, suggested that the expression of P16 may related to LF hypertrophy in the patients who suffer with LSS. LF hypertrophy process may not be associated with high expression of S100.

The aim of this study is to evaluate the safety and effectiveness in the treatment of thoracic aggressive vertebral hemangiomas (AVHs) with neurologic deficit by multiple surgical treatments.The clinical and radiographic data of 5 patients suffering from thoracic AVHs with neurologic deficit and treated by multiple surgical treatments, including percutaneous curved vertebroplasty (PCVP) combined with pedicle screw fixation and decompressive laminectomy, were reviewed and analyzed retrospectively.Five patients (3 women and 2 man, with a mean age of 57.40 ± 11.93) were diagnosed with AVHs from July 2010 to April 2016. All of them had objective neurologic deficit, myelopathy, and back pain. They underwent multiple surgical treatments and were followed-up for 12 to 23 months. At final follow-up, Frankel Grade D was achieved in all 5 patients. Patients were free from pain and neurologic symptoms, and the functional status was improved. No major complication was found.The treatment of AVHs with neurologic deficit is a challenge for surgeons. PCVP combined with pedicle screw fixation and decompressive laminectomy is safe and effective, and can be used for AVHs with neurologic deficit. Further studies with more samples are required to validate the effectiveness and safety of PCVP combined with pedicle screw fixation and decompressive laminectomy.

The purpose of this meta-analysis was to explore whether cervical disc arthroplasty (CDA) was superior to anterior cervical discectomy and fusion (ACDF) in reducing secondary surgery. PubMed, EMBASE, and the Cochrane Library databases were systematically searched. Outcomes were reported as relative risk (RR) with the corresponding 95% confidence interval (CI). The pooled data was calculated using a random-effect model. We also used the trial sequential analysis (TSA) to further verify our results and obtain more moderate estimates. Twenty-one studies with 4208 patients were included in this meta-analysis. The results indicated that compared with ACDF, CDA had fewer frequency of secondary surgery at the index level (RR, 0.47; 95%CI, 0.36-0.63; P < 0.05) and adjacent level (RR, 0.48; 95%CI, 0.36-0.65; P < 0.05), and the differences were statistically significant. In addition, in terms of the overall frequency of secondary surgery at the index and adjacent level, CDA was also significantly superior to ACDF (RR, 0.49; 95%CI, 0.41-0.60; P < 0.05). TSA demonstrated that adequate and decisive evidence had been established. Regarding the frequency of secondary surgery, CDA was significantly superior to ACDF. It was supposed that CDA may be a better surgical intervention to reduce the rate of secondary surgery for patients with cervical degenerative disc disease.