BACKGROUND: Total hip replacement in middle-aged patients is challenging regarding restoration and survival,because these patients are more active than old patients.OBJECTIVE: To retrospectively investigate whether a cementless prosthesis could restore hip function,decrease osteolysis,wear,and enhance prosthesis survival in middle-aged patients.METHODS: Clinical and radiological evaluations of patients undergoing single-side total hip replacement with cement and cementless prosthesis were analyzed preoperatively as well as at 6 months,1,4 and 7 years postoperatively.The outcomes of total hip replacement were assessed using Harris hip scores and survival rate.End point was loosening or revision of the femoral component for any reason.RESULTS AND CONCLUSION: Cementless prosthesis had gained better Harris hip scores than that of cement prosthesis group at 6 months,1,4 and 7 years postoperatively(P < 0.05).The survival rate was greater in cementless prosthesis compared with cement prosthesis during 7-year follow-up(P < 0.05).Results have suggested that cementless prosthesis achieves high rate of functional restoration and a low rate of complications in middle-aged patients following total hip replacement.

BACKGROUND: As an ideal scaffold of cartilage tissue engineering, demineralized bone matrix (DBM) has been widespread used. But some of biological characters remain poorly understood.OBJECTIVE: To determine the degradation capacity, interval porosity and adhesion rate of mesenchymal stem cells (MSCs) onto DBM in vitro.DESIGN, TIME AND SETTING: An observation experiment in vitro was complicated in Institute of Orthopedics, Second Hospital of Lanzhou University from January 8~(th) to April 15~(th) in 2005 and Central Laboratory of Guilin Medical University from August 1~(st) to November 15~(th) in 2007.MATERIALS: One chinchilla rabbit was killed under anesthesia. Referring to the method described by Urist, DBM was made by cancellated bone harvested from metaphysis and vertebral body METHODS: DBM was soaked into phosphate buffered solution to determine its degradation capacity; liquid replacement method was used to test its interval porosity; The 3~(rd) passage MSCs at a concentration of 1×10~8/L were cocultured with DBM in vitro and adhesion rate of MSCs onto DBM was tested using cytometry.MAIN OUTCOME MEASURES: The degradation capacity, interval porosity and adhesion rate of MSCs onto DBM.RESULTS: The degradation rate of DBM was accelerated with the prolonging of time, and the complete degrading time was about 10-12 weeks; The holing rate tested was (77.15±3.44)%; The 3~(rd) passage cells had a higher adhesive rate of 71.25% onto DBM.CONCLUSION: DBM degradation curve is consistent with MSCs proliferation curve, indicating a satisfactory adhesion capacity and interval porosity and DBM is an ideal biological scaffold material for cartilage tissue engineering.

BACKGROUND:Unilateral biportal endoscopic technique has been widely used in lumbar interbody fusion in recent years,but there is little comparison between its clinical efficacy and that of minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)in the treatment of lumbar degenerative disease,whether the unilateral biportal endoscopic technique is a safe and effective lumbar fusion remains to be further demonstrated. OBJECTIVE:To compare the clinical efficacy of unilateral biportal endoscopic lumbar interbody fusion(UBE-LIF)and MIS-TLIF in the treatment of lumbar degenerative diseases and explore a more efficient lumbar fusion procedure. METHODS:Patients with single-level lumbar degenerative disease were enrolled in Affiliated Hospital of Guilin Medical College from October 2020 to February 2022,including 35 patients who underwent UBE-LIF and 286 patients who underwent MIS-TLIF.Propensity score matching was used to eliminate confounders.Four covariates including sex,age,disease type and surgical segment were matched 1:1(caliper value 0.01).After matching,29 patients from each group were included in the study.The perioperative operative time,hemoglobin loss and hospital stay were compared between the two groups.Visual analog scale score and Oswestry disability index were used to evaluate the functional recovery of the two groups before,1,6 months and 1 year after operation.The excellent and good rate of the two groups was evaluated by the modified MacNab standard at the last follow-up.The fusion of the two groups was evaluated by Lenke Dynamic X-ray film. RESULTS AND CONCLUSION:(1)The operative time in the MIS-TLIF group was shorter than that in the UBE-LIF group(P＜0.05).The amount of intraoperative hemoglobin loss in the MIS-TLIF group was higher than that in the UBE-LIF group.The hospital stay in the MIS-TLIF group was longer than that in the UBE-LIF group,and the differences were statistically significant(P＜0.05).(2)The visual analog scale scores for lumbago and leg pain,and Oswestry disability index were significantly reduced in both groups 1,6 months,and 1 year after surgery compared to before surgery(P＜0.05).Except for the visual analog scale score for lumbago at 1 month after surgery,there was no significant difference in the visual analog scale score for lumbago and leg pain,and Oswestry disability index between the two groups at the above time points(P＞0.05).(3)At the last follow-up,the modified MacNab standard efficacy evaluation showed that the excellent and good rates were 93%(27/29)in the UBE-LIF group and 90%(26/29)in the MIS-TLIF group;there was no significant difference between the two groups(P＞0.05).(4)Lenke dynamic radiographic evaluation system evaluation for lumbar fusion exhibited that the fusion rate was 90%(grade A,21 cases;grade B,5 cases;grade C,3 cases)in the UBE-LIF group;the fusion rate was 86%(grade A,20 cases;grade B,5 cases;grade C,4 cases)in the MIS-TLIF group;there was no significant difference between the two groups(P＞0.05).(5)It is indicated that UBE-LIF and MIS-TLIF have similar clinical effects in the treatment of single-level lumbar degenerative disease with the advantages of less trauma,less bleeding and shorter hospital stay.In addition,the early postoperative lumbago was relatively mild and the learning curve was relatively smooth.Although the operative time in the UBE-LIF group was longer than that in the MIS-TLIF group,it was still a safe and effective operation.