Comparison of the anterior and posterior approach in treating four-level cervical spondylotic myelopathy

Background:The optimal surgical approach for four-level cervical spondylotic myelopathy remains controversial.The purpose of this study was to compare clinical and radiological outcomes and complications between the anterior and posterior approaches for four-level cervical spondylotic myelopathy.Methods:A total of 19 patients underwent anterior decompression and fusion and 25 patients underwent posterior laminoplasty and instrumentation in this study.Perioperative information,intraoperative blood loss,clinical and radiological outcomes,and complications were recorded.Japanese Orthopedic Association(JOA)score,36-item short form survey(SF-36)score and cervical alignment were assessed.Results:There were no significant differences in JOA scores between the anterior and posterior group preoperatively(11.6±1.6 vs.12.1±1.5),immediately postoperatively(14.4±1.1 vs.13.8±1.3),or at the last follow-up(14.6±1.0 vs.14.2±1.1)(P>0.05).The JOA scores significantly improved immediately postoperatively and at the last follow-up in both groups compared with their preoperative values.The recovery rate was significantly higher in the anterior group both immediately postoperatively and at the last follow-up.The SF-36 score was significantly higher in the anterior group at the last follow-up compared with the preoperative value(69.4 vs.61.7).Imaging revealed that there was no significant difference in the Cobb angle at C2-C7 between the two groups preoperatively(-2.0°±7.3°vs.-1.4°±7.5°).The Cobb angle significantly improved immediately postoperatively(12.3°±4.2°vs.9.2°±3.6°)and at the last follow-up(12.4°±3.5°vs.9.0°±2.6°)in both groups compared with their preoperative values(P=0.00).Three patients had temporary dysphagia in the anterior group and four patients had persistent axial symptoms in the posterior group.Conclusions:Both the anterior and posterior approaches were effective in treating four-level cervical spondylotic myelopathy in terms of neurological clinical outcomes and radiological features.However,the JOA score recovery rate and SF-36 score in the anterior group were significantly higher.Persistent axial pain could be a major concern when undertaking the posterior approach.

Effect of Resveratrol on Preventing Steroid-induced Osteonecrosis in a Rabbit Model

Background： Prevention of osteonecrosis （ON） has seldom been addressed. The purpose of this study was to evaluate the effect of resveratrol on preventing steroid-induced ON in rabbits. Methods： Seventy-two rabbits were divided into four groups： （l） NEC （ON） group： thirty rabbits were treated with lipopolysaccharide （LPS） once, then with methylprednisolone （MPS） daily for 3 days; （2） PRE （prevention） group： thirty rabbits were given one dose of LPS, then MPS daily for 3 days, and resveratrol on day 0 and daily for 2 weeks： （3） RES （resveratrol） group： six rabbits were given resveratrol for 2 weeks but without LPS/MPS; （4） CON （control） group： six rabbits were given alcohol for 2 weeks but without LPS/MPS. Levels of plasma tissue-type plasminogen activator （t-PAL plasminogen activator inhibitor 1 （PAl-1）, thrombomodulin （TM）, vascular endothelial growth factor （VEGF）, maximum enhancement （ME） by magnetic resonance imaging, and ON incidence were evaluated. Results： The PRE group had a lower ON incidence than the NEC group, but with no significant differences at 2 weeks and 12 weeks. Tile RES and CON groups did not develop ON. TM and VEGF were significantly higher in the NEC group compared with the PRE group at weeks 1, 2, and 4 （TM： 1 week, P= 0.029; 2 weeks, P= 0.005; and 4 weeks, P = 0.047; VEGF： 1 week, P= 0.039; 2 weeks, P= 0.021; 4 weeks. P = 0.014） but the difference disappeared at 12 weeks. The levels of t-PA and PAl-I were not significantly different between the NEC and PRE groups. The TM, t-PA, PAl-l, and VEGF concentrations in the RES and CON groups did not change over time. Compared to the baseline, ME in the NEC group decreased significantly （P = 0.025） at week 1, increased significantly （P = 0.021） at week 2, and was decreased at week 12. The variance was insignificant in the PRE group. Conclusions： Resveratrol may improve blood supply to bone in a rabbit model of ON of the femoral head via anti-inflammatory effects to protect the vascular endothelium and reduce thrombosis.

A Case of Implant Migration Following Bi-level Cervical Disc Arthroplasty

To the Editor： A 48-year-old female underwent C4/5 and C5/6 Bryan cervical disc arthroplasty 3 years earlier for right shoulder pain and right arm numbness and weakness. The symptoms resolved postoperatively, and the location of the implant was good 6 weeks after the surgery; however, the range of motion （ROM） of the C4/5 and C5/6 implant were only 1° and 4°, respectively. The patient complained of the right shoulder pain and swallowing difficulty 10 months postoperatively. She experienced no neurological symptoms, and physical examination revealed no abnormal findings. Her symptoms progressively deteriorated, and she began to have difficulty of swallowing solid food. Thirteen months after the surgery, anteroposterior and lateral radiographs showed anterior migration of the C4/5 and C5/6 implants [Figure 1 ]. Preoperative serum procalcitonin, erythrocyte sedimentation rate, and C-reactive protein levels were normal.