[Objective]To explore the efficacy and result of femoral component revision by using impaction bone grafting technique with anatomic cemented stem and freeze-dried allograft.[Method]Anatomic cemented stem combined with freeze-dried allograft were used in IBG for 49 cases of femoral revisions from Jan,2001 to Dec 2005.36 cases(73%)of which had severe bone loss(Paprosky grades ⅢB and Ⅳ).The mean follow-up time was 35.3 months(26~52 months).Harris Hip Score System and radiography were used to evaluate the clinical results.[Result]The mean Harris Hip Score was improved from 44.6 points preoperatively to 88.3 points at final evaluation.Good and excellent scores were about 89.8%.No major femoral stem subsidence was found in our patients.There were one case of dislocation(2%),one case of deep infection(2%)and 3 cases of femoral fractures during operations(6.1%),which were not related to the selection of femoral component and the type of allograft.[Conclusion]The impaction bone grafting technique by using freeze-dried allograft and the anatomic cemented femoral prosthesis for femoral revision was feasible and the short and mid-term result was good.Longer follow-up was needed to evaluate the long term result.

BACKGROUND:The traditional repair methods for laryngeal cartilage defect are restricted by donor source, rejection, which are difficult to be popularized. OBJECTIVE:To investigate the effect of polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold in repair of laryngeal cartilage defect. METHODS: A total of 20 Wistar rats were randomly divided into polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold and polylactic acid-glycolic acid copolymer scaffold groups. Polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold and polylactic acid-glycolic acid copolymer scaffold were respectively used for repair after the establishment of laryngeal cartilage defect models. RESULTS AND CONCLUSION: The laryngeal cartilage defect diameter of rats at 3, 5 and 7 days after modeling in the polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold group was significantly smaler than that in the polylactic acid-glycolic acid copolymer scaffold group. The laryngeal cartilage defect of rats in the polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold group was basicaly repaired and presented with a smooth surface, and there were no clear boundaries with surrounding tissues; however, the laryngeal cartilage defect of rats in the polylactic acid-glycolic acid copolymer scaffold group had indentations with a rough surface, and there were obvious boundaries with surrounding tissues. These results demonstrate that polylactic acid-glycolic acid copolymer/hydroxyapatite composite scaffold can promote the repair of laryngeal cartilage defect part, and its repair effect is more ideal.

[Objective]To evaluate the role of mobile bearing knee prosthesis in TKA and the clinical results.[Method]A total of 301 TKAs by using mobile bearing knee prosthesis were gotten average 48.7 months follow-up.HSS knee scores and X-ray films were to used to evaluate the results.[Result]The mean HSS score improved from 51.3 before operation to 91.3 after operation.The ROM improved from extension/flexion(-9.5?/64.3?)before operation to extension/flexion(0?/97.5?)after operation.The maximum varus/valgus(25?/15?)before operation were improved to the mean valgus 5.3?.Two cases of septic loosening and 2 cases of femoral fracture were found.[Conclusion]The CR type mobile bearing knee prosthesis not only had advantages in kinematics and wear experiments,but also had achived good clinical result.

Objective To discuss the treatment of intraoperative periprosthetic fractures on the femoral side,and to evaluate the results of functional recovery after treatment.Methods Fifty-four cases of intraoperative periprosthetic fractures on the femoral side encountered from July 2002 to December 2006 were retrospectively studied.Fractures on the femoral side were classified by Mallory classification system.X-ray films were taken to evaluate the healing patterns of the fractures.Results Cerclage wires were adequate for stable type I and type Ⅱ fractures,while it could be treated expectantly when the fracture did not involve proximal femur in stable type Ⅱ.Unstable type Ⅱ fractures were taken care of with a long-stem uncementoid component.Type Ⅲ fractures were taken care of with a long-stem uncementoid component or LCP plate.Additional cortical strut allografts were used for the management of unstable fractures and the fractures with poor host bone stock.The average follow-up time was 23.5 months(5-52 months).All fractures were healed as shown by radiography except one case of type I fracture.There was no evidence of loosening or periprosthetic osteolysis on follow up radiograph.The mean postoperative Harris Hip Score was 94.5.Conclusion The treatment of intraoperative periprosthetic fracture around the femoral implant can successfully restore the function of the hip joint in most patients.Cerclage wires,long-stem uncementoid component and additional cortical strut allograft were effective treatment methods for different types of intraoperative periprosthetic fractures on the femoral side.Expectant treatment can achieve satisfactory result in stable type II fractures when the fracture did not destroy proximal femur.

Objective To study the contribution of cortical strut allografts for periprosthetic femoral fractures in total hip arthroplasty. Methods A retrospective study was performed with the data of 22 patients who were admitted from Oct. 2002 to Jul. 2006 and had used strut allografts in the treatment for periprosthetic femoral fracture. Fractures occurred intraoperatively in 18 patients and postoperatively in 4 patients. Of the 22 patients, 4 cases were classified as type A, 13 as type B and 5 as type C fractures according to the Vancouver Classification System. All the fractures were treated with non-cemented stem and supported by cortical strut. The allografts were fixed to the femur by cerclage wire and/or cables. Functional outcome was measured by the Harris hip score. Results All patients were followed-up for a mean of 27.5 months (range of 8-45 months). Fracture union was achieved in 6-14 weeks (range of 16.5 weeks) in 21 patients. The strut fractured at 17 weeks postoperatively in another one patient. The integration of allograft and host bone was confirmed by X-ray examination in all patients at the final follow-up. One patient experienced pain in the affected limb, and stiffness in the ipsilateral knee occurred postoperatively in 3 patients. Conclusions Cortical strut allograft can provide both mechanical and biological stability as biological bone plates. Fixation of cortical strut allograft is a useful technique for the management of periprosthetic femoral fractures, and can lead to a high rate of fracture union and increase the host bone mass during the period of a short-term follow-up. It suggests that the cortical strut allograft should be used routinely to strengthen fixation in periprosthetic femoral fractures.

[Objective]To explore the efficacy and results of tibial tubercle osteotomy used in exposure in complicated total knee arthroplasty.[Methods]During the period from Apr.2005 to Apr.2007,the tibial tubercle osteotomy were used in 16 cases of complicated total knee arthroplasty.The mean follow-up time were 20 months(6～26 months).Knee society score(KSS) and radiography were used to evaluate the clinical results.[Results]The mean KSS improved from 46 points preoperatively to 91 points postoperatively.The mean ROM improved to from 53?preoperatively 105?postoperatively.At 3 months after surgery the radiography examines showed all 16 cases had achieved satisfactory healing.The tubercle fragment slided toward proximal 0.7 cm occurred in one case,and finally healed at that position.[Conclusion]Exposure of the knee may be difficult in the total knee arthroplasty,but tibial tubercle osteotomy is a safe and reliable procedure which affords excellent exposure.

[Objective]To evaluate the safety outcome of the 12 patients with simultaneous multiple joint replacement(≥3) in the recent three years.[Method]The complication rates,blood loss,transfusion volume,and hospital stay were analyzed in details.[Result]The mean operating time was 9 hours and 8 minutes(6 hours and 25 minutes to 12 hours).The mean overall volume of blood loss was 3140ml(1 000 ml-5 600 ml.Complications included reactive digestive ulcer in one case,acetabular component position error in one case,and deep infection in one hip of one case.[Conclusion]Simultaneous multiple joint replacement is an alternative protocol to the patients with multiple joint disorders.finished under a single aesthesia and in a single hospital stay.So the overall economical cost will be decreased,and rehabilitation being accelerated.Disadvantages include serious trauma,increased blood loss,and complications may be some how increased.

[Objective]To review our experience in treatine infection after total knee arthroplasty with debridement and component retention to determine To the feasibility,indication,factors related to success and failure,and the main points of technique.[Method]Since 1990 to 2004,9 patients were treated with debridement and component retention at our department.[Result]Four of 9 patients successfully retained their component at most recent follow-up,without ongoing infection(mean 18 months,range 10～25 months).We have not draw the statistically significant factors that related to successful and failure,but the factors such as acute infection,surfacing replacement,immediate debrided after onset of symptoms,and the bacteria sensitive to antibiotic were relate to success.[Conclusion]Debridement and component retention can be used in acute postoperative infection and later acute hematogenous infection after total knee replacement,but timing and indication must be chosen strictly.

Objective Experimental and clinical data suggest that fixed element knee designs a re not able to both supply adequate mobility and eliminate unnecessary constra int forces,as well as provide low contact stresses compatible with pr olonged life of UHMWPE bearing components.The present study investi-gated the preliminary clinical outc ome of TACK(Total Articulating Cementless Knee)system,a new design of mobile-bearing knee prosthesis.Methods Eighty-eight knees in 61patients underwent total knee replace-ment by using TACK were reviewed.Forty-five knees of 31patients were followed-up at least one year.The HSS knee rating score system as well a s X-ray films were used to evaluate th e clinical results with the mean follow-up period of 25.4months.Results At the latest follow-up examination,the rate of good to excellent clinical results was 96.4%.The range of motion was improved from 0-6.5-68.3degrees preoperatively to0-2-88.4degrees at the latest follo w-up.The complications such as oste olysis around the prosthesis,prosthetic loosening and dislocation of meniscus bearings were not found.Conclusion The TACK Knee is a third generation knee system design ed to introduce movable bearings between the metal tibial and femoral components that would reduce the sur face and subsurface stress states at the bearing surfaces and at the bone-implant interfaces by maximiz ing the conformity of the tibial and f emoral components and allowing mo-bility of the bearing surface.In an a verage of more than two years experie nce,it was observed that there was no aseptic loosening of the componen ts.A long term follow-up is obviously necessary to make more precise statement about this knee replaceme nt system.

Objective To assess the population pharmacokinetic parameters for propofol for Chinese surgical patients using a nonlinear mixed- effect model (NONMEN) program and qualitatively analyze the effects of gender, age and body weight.Methods Seventy-six ASA I - II patients(37 male,39 female) ,aged 17-77 years weighing 39-86 kg. Undergoing elective surgery were studied. The patients were premedicated with intramuscular sodium luminal 0.1 g and scopolamine 0.3 mg. Radial artery was cannulated for blood pressure monitoring and blood sampling. BIS, AEPindex, EGG, BP, PET CO2 and SpO2 were continuously monitored during operation. Anesthesia was induced and maintained with propofol and fentanyl. A loading dose of fentanyl 3 ?g? kg-1 was given iv followed by infusion at 2 ?g ? kg -1? h-1 until 30 min before the end of surgery. Propofol 1 -2.5 mg ?kg -1 was given iv over 0.5-4 min followed by infusion at 3-8 mg ? kg-1? h-1 until the end of surgery. When the patient was unconscious intubation was facilitated with vecuronium 0.1 mg? kg-1 . Blood samples were obtained before propofol and 2-120 min during propofol infusion and 2-600 min after discontinuation of propofol infusion for determination of blood propofol concentration. 1 439 blood samples were analyzed using NONMEM program. Interindividual and intraindividual variability was estimated for clearance and volume of distribution. The effects of age, body weight and gender were investigated. Results The pharmacokinetics of propofol in Chinese patients was best described by a three-compartment pharmacokinetic model . Body weight was found to be a significant factor affecting the two inter-compartmental clearances and the volume of the central compartment. The shallow and deep peripheral compartments remained constant for all individuals. For a 60 kg adult these parameters were estimated to be 1.56 L?min-1, 0.737 L?min-1 , 0.360L?min-1 ,12.1 L,43 L,213 L,respectively. For elderly patients, the clearances and volume of central compartment decreased with increasing age. Conclusions The pharmacokinetics of propofol in Chinese patients can be well described by a standard three-compartment pharmacokinetic model. Age and body weight can affect the parameters of the pharmacokinetic model. Pharmacokinetics adjusted to the individual patient should improve the precision of TCI system.