Objective To compare the efficiency of explants adherent after enzymatic pre-digestion and traditional typeⅡ?collagenase digestion methods for culturing human nucleus pulposus cells from degenerated intervertebral discs.Methods Human nucleus pulposus tissues collected from patients'degenerated intervertebral discs were divided into Groups A and B.In Group A,the nucleus pulposus tissues were cultured using explants adherent method directly after 0.025 ％ typeⅡ?collagenase digestion for 30 minutes.In Group B,the tissues were firstly digested with 0.025 ％ typeⅡ?collagenase for five hours,and then underwent filtration,centrifugation and inoculation successively Success rate and primary cell fusion time of the two culture methods were compared.Cell morphology and expressions of sex determining region Y-box 9(Sox-9),collagenⅡ?and aggrecan were observed by HE staining,toluidine blue staining and immunofluorescence cell staining.Results There was no significant difference in the successful culture rate between the two groups(P＞0.05).However,the average fusion time of primary passage in Group A was significantly shorter than that in Group B(P＜0.01).In Group A,the nucleus pulposus cells could be stained as azure by toluidine blue and immunofluorescence cell staining showed positive expressions of Sox-9,collagenⅡ?and aggrecan.Conclusions Compared with traditional typeⅡ?collagenase digestion,explants adherent method after typeⅡ?collagenase pre-digestion for the culture of human nucleus pulposus cells from degenerative intervertebral discs has a high success rate and obtains a large number of cells in a short time.Meanwhile,the cells have strong expressions of Sox-9,collagenⅡ?and aggrecan.

Objective To investigate the clinical effect of Ethibond suture and anchor fixation by arthroscopic technique for the treatment of avulsion fracture of the anterior cruciate ligament (ACL) tibial insertion.Methods Twenty patients with avulsion fracture of the ACL tibial insertion hospitalized between July 2013 and June 2014 were collected retrospectively.There were 12 males and 8 females,aged 18-41 years (mean,25.3 years).All patients were identified with type Ⅱ and type Ⅲ fractures according to the Meyers-McKeever classification.Results of Lachman test and anterior drawer test were both positive.All patients accepted the operation that avulsion fracture of the ACL tibial insertion was treated with the Ethibond suture and anchor fixation by arthroscopic technique within 3 weeks after injury.Follow-up X-ray examinations were carried out to evaluate the bone union.Lysholm and international knee documentation committee (IKDC) scores were used to evaluate the function of knee joint postoperatively.Results Operation time was 45-70 min (mean,50 min).Blood loss was 5-15 ml (mean,10 ml).Follow-up was conducted for 12-24 months (mean,16.3 months).Postoperative X-ray showed the reduction was satisfactory.Lachman test and anterior drawer test were both negative after operation.Knee functions were recovered to normal.Lysholm and IKDC scores were 89-96 points [(93.5 ± 2.3) points]and 84-96 points [(91.0 ± 3.9)points] respectively at the final follow-up,improved compared to the preoperative 42-61 points [(51.1 ± 6.2) points] and 46-68 points [(55.2 ± 7.0) points] (both P ＜0.05).Conclusion Arthroscopic Ethibond suture and anchor fixation for avulsion fracture of the ACL tibial insertion is an effective procedure with the advantages of small trauma,reliable fixation,good functional recovery and satisfactory clinical effect.