Dongfeng Ren

Four-year follow-up results of transforaminal lumbar interbody fusion as revision surgery for recurrent lumbar disc herniation after conventional discectomy

This study investigated the safety, effectiveness, and clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) for recurrent lumbar disc herniation (rLDH) following previous lumbar spine surgery. Seventy-three consecutive patients treated for rLDH between June 2005 and May 2012 were included in the study. The previous surgical procedures included percutaneous discectomy, discectomy with laminotomy, discectomy with unilateral laminectomy, and discectomy with bilateral laminectomy. The level of rLDH was L4-L5 in 51 patients, L5-S1 in 19 patients, and L3-L4 in three patients. All patients underwent reoperation using the TLIF technique. Outcomes were evaluated using the Oswestry disability index (ODI), visual analogue scale (VAS) scores for low back pain and leg pain, and the Japanese Orthopaedic Association (JOA) score, based on the results of physical examinations and questionnaires. The range of motion and disc height index of the operative segment were compared between preoperative and postoperative radiographs. The mean follow-up period was 4.1 years. The VAS scores for low back pain and leg pain, ODI, and JOA score improved significantly between the preoperative and final follow-up evaluations. The mean recovery rate of the JOA score was 89.0%. The disc space height and stability at the fused level were significantly improved after surgery. The fusion rate at the final follow-up was 93.2%. There were no major complications. These results indicate that TLIF can be considered an effective, reliable, and safe alternative procedure for the treatment of rLDH.

Percutaneous Resolution of Lumbar Facet Joint Cysts as an Alternative Treatment to Surgery: A Meta-Analysis

Purpose A comprehensive review of the literature in order to analyze data about the success rate of percutaneous resolution of the lumbar facet joint cysts as a conservative management strategy. Methods A systematic search for relevant articles published during 1980 to May 2014 was performed in several electronic databases by using the specific MeSH terms and keywords. Most relevant data was captured and pooled for the meta-analysis to achieve overall effect size of treatment along with 95% confidence intervals. Results 29 studies were included in the meta-analysis. Follow-up duration as mean ± sd (range) was 16±10.2 (5 days to 5.7 years). Overall the satisfactory results (after short- or long-term follow-up) were achieved in 55.8 [49.5, 62.08] % (pooled mean and 95% CI) of the 544 patients subjected to percutaneous lumbar facet joint cyst resolution procedures. 38.67 [33.3, 43.95] % of this population underwent surgery subsequently to achieve durable relief. There existed no linear relationship between the increasing average duration of follow-up period of individual studies and percent satisfaction from the percutaneous resolutions procedure. Conclusion Results shows that the percutaneous cyst resolution procedures have potential to be an alternative to surgical interventions but identification of suitable subjects requires further research.

AQP9: A novel target for bone loss induced by microgravity

The aim of current study was to elucidate whether aquaporin-9 (AQP9) expression was involved in the progression of bone loss induced by microgravity. We used the hind-limb suspension (HLS) mice model to simulate microgravity and induce bone loss. It was found that HLS exposure decreased femur bone mineral density (BMD), and enhanced femur AQP9 mRNA and protein levels. Then, the relationship between AQP9 mRNA expression and BMD was studied and it was showed that femur AQP9 mRNA level was negatively related to femur BMD in mice exposed to HLS. We sought to exam the function of AQP9 in the femur using the AQP9-null mice. It was found that AQP9 knockout attenuated bone loss and inhibited osteoclastogenesis under the condition of HLS exposure, but had no similar effect on bone under normal physiological conditions. In addition, it was found that exposure to simulated hypergravity or exercise training, main countermeasures against microgravity, reduced AQP9 mRNA and protein levels in femur of mice. Moreover, it was found that both aging and estrogen deprivation, another two risk factors of bone loss, had no significant effect on femur AQP9 expression. In conclusion, AQP9 plays an important role in the development of microgravity-induced bone loss, and may be a potential target for the prevention or management of microgravity-induced bone loss.

Increased expression of netrin-1 and its deleted in colorectal cancer receptor in human diseased lumbar intervertebral disc compared with autopsy control.

Study Design. The expression of netrin-1 and its deleted in colorectal cancer (DCC) receptor was investigated in human lumbar discs using immunohistochemistry. Objective. To investigate the expression of netrin-1 and DCC receptor in human diseased and healthy lumbar intervertebral discs (IVDs) and to clarify the correlation between netrin-1 expression and the degree of neurovascular ingrowth. Summary of Background Data. Previous studies have shown neurovascular ingrowth into the inner regions of degenerated IVD and suggested that the ingrowth may contribute to discogenic low back pain. Netrin-1 is an axon guidance molecule that regulates axons seeking their final targets and has been identified as involved in various pathological conditions, so is its DCC receptor. However, the role of netrin-1 in diseased IVDs remains unknown. Methods. Thirty-five diseased IVD specimens were collected from 34 patients with different lumbar diseases during posterior lumbar interbody fusion. Eight normal discs were obtained at autopsy as control. Using polyclonal or monoclonal antibody, the disc slides were immmunostained to detect the expression and distribution of netrin-1, the DCC, the neuronal marker (neurofilament), and the vascular endothelial cell marker (CD34). Results. Netrin-1 and DCC immunopositive cells distributed substantially from the annulus fibrosus to the nucleus pulposus (NP), and the immunopositivity was detected in the disc cells, endothelial cells and granulation tissue cells in the diseased discs. The percentage of netrin-1 positive disc cells of the NP was more than that of the annulus fibrosus. The expression of netrin-1 and DCC was weak in the normal discs. A significant positive correlation between the percentage of netrin-1 immunopositive disc cells and neurovascular scores was found. Conclusion. The increased expression of netrin-1 and DCC in diseased IVDs compared with controls suggested that they might play an important role in the process of neurovascular ingrowth.

Adipose-derived stem cells improve the viability of nucleus pulposus cells in degenerated intervertebral discs

Patients with degenerative disc disease (DDD) experience serious clinical symptoms, including chronic low back pain. A series of therapies have been developed to treat DDD, including physical therapy and surgical treatment. However, the therapeutic effect of such treatments has remained insufficient. Recently, stem cell‑based therapy, in which stem cells are injected into the nucleus pulposus in degenerated intervertebral disc tissue, has appeared to be effective in the treatment of DDD. In the present study, the effect of adipose‑derived stem cells on degenerated nucleus pulposus cells was investigated using a co‑culture system to evaluate the biological activity of degenerated nucleus pulposus cells. Human degenerated nucleus pulposus tissue was obtained from surgical specimens and the adipose‑derived stem cells were derived from adipose tissue. The degenerated nucleus pulposus cells were cultured in a mono‑culture or in a co‑culture with adipose‑derived stem cells using 0.4‑µm Transwell inserts. The results indicated that adipose‑derived stem cells were able to stimulate matrix synthesis and the cell proliferation of degenerated nucleus pulposus cells, promoting the restoration of nucleus pulposus cells in the degenerated intervertebral disc.

Comparison of Three Reconstructive Techniques in the Surgical Management of Patients With Four-level Cervical Spondylotic Myelopathy

Study Design. Retrospective clinical series. Objective. To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of three reconstructive techniques after the anterior decompression of four-level cervical spondylotic myelopathy (CSM). Summary of Background Data. At present, the decision to treat multilevel CSM, especially four-level CSM, remains controversial. No one compares multilevel anterior cervical discectomy and fusion (mACDF), segmental anterior cervical corpectomy and fusion (sACCF) to multilevel anterior cervical discectomy and fusion with cage alone (mACDF-CA) in four-level constructs. Methods. Between July 2006 and February 2014, 97 consecutive patients with four-level CSM were enrolled in this study and divided into sACCF (n = 39) group, mACDF (n = 31) group, and mACDF-CA (n = 27) group. The study compared perioperative parameters, complication rates, clinical and radiologic parameters of three reconstructive techniques after the anterior decompression of four-level CSM. Results. The mACDF-CA group had the least bleeding and cost of index surgery compared with the sACCF group having the most bleeding and cost. Although significant pain relief and functional activity improvement have been achieved in the three groups at the final follow-up, there was no significant difference in the Japanese Orthopedic Association, SF-36 and NDI scores among the three groups (P >0.05). The mACDF group maintained the best cervical lordosis at the final follow-up, compared with the sACCF group maintained the worst cervical lordosis. Solid fusion was achieved in 87.1% of subjects in sACCF group, 90.3% in mACDF, and in 88.9% in mACDF-CA. The mACDF-CA group had a higher rate of subsidence and lower rate of dysphagia than other two groups. Conclusion. mACDF-CA can be considered an effective and safe alternative procedure in the treatment of the four-level CSM. Level of Evidence: 4

Efficacy and Safety of One-Stage Selective Discectomy Combined with Expansive Hemilaminectomy in the Treatment of Cervical Spondylotic Myelopathy

OBJECTIVES We designed a novel surgical strategy named one-stage selective discectomy combined with expansive hemilaminectomy, which might theoretically reduce the postoperative complications of cervical spondylotic myelopathy (CSM). The objective of this study is to evaluate its efficacy and safety. METHODS Sixty-two patients with CSM were enrolled in this study. The procedure includes selective discectomy with fusion at 1 or 2 segments of maximal cord compression and expansive hemilaminectomy on the symptomatic or severe side of the body. Neurologic function was evaluated using the Japanese Orthopedics Association Score before and after surgery. Midsagittal dural sac diameter, dural sac transverse area at segments of discetomy on magnetic resonance imaging, and lordosis of the cervical spine on lateral plain film were measured. All patients were followed up for more than 1 year. RESULTS A total of 88 discs and 272 hemilaminas were resected from 62 patients. The Japanese Orthopedics Association Score improved from 8.7 ± 1.76 preoperatively to 13.4 ± 1.61 at 1 year follow-up (P < 0.001). The mean midsagittal dural sac diameter, dural sac area, and lordotic angle also increased from 0.45 ± 0.10 cm, 0.83 ± 0.14 cm2, and 7.9 ± 2.60° to 0.81 ± 0.08 cm, 0.96 ± 0.14 cm2, and 11.7 ± 3.06°, respectively (P < 0.05). No case of postoperative axial pain, C5 palsy, nonunion, or kyphosis was reported. CONCLUSIONS One-stage selective discectomy combined with expansive hemilaminectomy is an effective surgical approach for the treatment of CSM in patients whose neurologic function, midsagittal dura sac diameter, and dura transverse area can be improved and has few postoperative complications.

Risk factors and the surgery affection of respiratory complication and its mortality after acute traumatic cervical spinal cord injury.

Abstract The aim of this study is to estimate the risk factors of both respiratory complication (RC) and mortality after acute traumatic cervical spinal cord injury (TCSCI). Between July 2005 and July 2015, in 181 patients (142 males and 39 females; mean age 41.0 years) with acute TCSCI, we compared the difference and odds ratio in RC group (n = 73) with that of non-RC group (n = 108), and also death group (n = 15) and survival group (n = 166). We collected injury-related information after half a year of injury, which is as follows: the causes of injury, time of surgery, ICU (intensive care unit) days, ventilator days, ASIA (American Spinal Injury Association) classification, neurological injury, CIPS (Clinical Pulmonary Infection Score), and BMI (body mass index). Besides these, we gathered the general information such as age, gender, smoking history, and use of steroids. The study compared perioperative parameters; surgery-related and instrumentation- and graft-related complication rates; clinical parameters; patient satisfaction; and radiologic parameters. Variations like gender (odds ratio [OR] = 1.269, 95% confidence interval [CI] [0.609–2.646]), smoking history (OR = 2.902, 95% CI [1.564–5.385]), AIS grade (grade A) (OR = 6.439, 95% CI [3.334–12.434]), neurological level (C1-C4) (OR = 2.714, 95% CI [1.458–5.066]), and steroid use (OR = 2.983, 95% CI [1.276–6.969]) have a facilitated effect on RC. When we estimated surgery-related affection, only the time of surgery and anterior approach compared with posterior has significant difference in RC (P < .05). Between death and survival group, the aspect of age, non-surgical, CPIS, AIS grade, and BMI have statistically significant difference. Survival analysis reveals significant difference in aforementioned groups. In patients suffering from acute TCSCI, those who are old, have long smoking history, complete spinal cord injury, C1-C4, high CPIS, and fat have high incidence of RC and mortality.

A new zero-profile, stand-alone Fidji cervical cage for the treatment of the single and multilevel cervical degenerative disc disease

To investigate the clinical and radiological results of the new zero-profile, stand-alone Fidji cervical cage to treat single- and multiple-level cervical DDD, and evaluate the safety and efficiency. Between October 2011 and July 2014, 72 consecutive patients (41 males and 31 females; mean age 50.9years [range, 33-68years]) with cervical DDD who underwent surgery and were followed for more than 2years were enrolled in this study (mean 31.1months, range 24-47months). The study compared clinical outcomes, radiologic parameters and complication rates. The SF-36, VAS, NDI, and JOA scores of all patients were improved significantly after surgery at any time point. (all p<0.05). The C2-C7 Cobb angle and the disc height index (DHI) of all patients were improved significantly after surgery at any time point (all p<0.05). From 3months after surgery to final follow-up the DHI showed a significant reduction comparing 1week after surgery (all p<0.05). The fusion rates were 91.7% (66/72) and the radiologic mean fusion time was 9.9months. Radiological evidence of adjacent segment degeneration (ASD) was observed in 4/41 patients (9.8%). Postoperative complications included epidural hematoma, hoarseness, dysphagia, axial neck pain, and subsidence. The zero-profile, stand-alone Fidji cervical cage for ACDF can be considered an effective, reliable and safe alternative procedure in the treatment of cervical DDD.