[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 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 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.

The effect of the selective debridement with the aid of the arthroscope performed under local anesthesia for osfeoarthritis of 296 knees in 260 patients was studied. The pathological changes of osteoarthritis under the arthroscopy include hyperplasia of synovial membrane, degeneration of cartilage or exposure of subchondral bone on the stress areas of the femur condyles and patella , wear and tear of meniscus, formation of osteophyte and loose body. The debridement included the removal of the loose body, hyperplasia of synovial membrane, degenerated cartilage, and the torn meniscus. Many factors,including age of the patients, selection of the indication, stress of the knee joint, and the degeneration of cartilage,may influence the curative effect. After selecfive debridement and lavage for osteoarthritis of the knee joint, the majority of patients were released from pain, with restoration of function and range of motion, and the development of pathological process was retarded. Good and excellent results constitute 74.7% of the patients.

Objective To compare the results of one-stage bilateral total hip arthroplasty (THA) and staged bilateral THA, and to determine the safety and efficacy of one-stage simultaneous bilateral THA. Methods The patients who were indicated for with bilateral THA were divided into 2 groups. Gourp A included 87 patients with one-stage simultaneous bilateral THA, and Group B included 31 patients with staged bilateral THA. The operating time, the amount of blood loss, the amount of blood transfusion necessary, post-operation functional scores, and perioperative complications were compared between group A and group B. Result There was no significant difference between group A and group B. Conclusion One-stage simultaneous bilateral total hip arthroplasty was a safe and efficacious procedure.

Objective A two-stage renovation has nowadays been considered as the optimal mode for the treatment of infected total hip joint.Extensive bone defects were often found during the subsequent operation,and they should be repaired by using allograft to attain stability of the implants.The purpose of present study is to investigate the efficacy and safety of employing bone allograft in repairing the femoral defect caused by post-operation infection of hip arthroplasty in the second stage operation.Method From Mar.2001 to Dec. 2006,a total of 20 patients(20 hips)with infected total hip arthroplasty were treated with bone allograft on the femoral side in the second operation.Impaction bone grafting technique was performed for 16 patients using bone allograft combined with cemented stems,and un-ce- mented prosthesis combined with bone strut allograft were used in the other 4 cases.A regular follow-up was done and the outcomes were evaluated using the Harris Hip Score System and radiography.Result All patients were followed-up clinically and radiographically for an average of 20.3 months(4-61 months).No re-infection was found at the last time of follow-up.The mean Harris Hip Score was in- creased from 34.2 before operation to 87.7 after operation.90% of the patients were satisfactory with the results.Conclusion The bone allograft can be used for reconstructing bone defects in the patients after infection of total hip arthroplasty,either with combined with ce- mented stems or non-cemented stems.It is an effective and safe way in dealing with femoral bone defect after infection of total hip arthro- plasty.

[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 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.