BACKGROUND:Unicompartmental knee arthroplasty has been prevailed in orthopedics,but there is a lack of overview addressing unicompartmental knee prostheses.OBJECTIVE:To review the evolution and current situation of unicompartmental knee prostheses and to discuss its classifications,characters and clinical outcomes,thereby providing guidance for clinical application.METHODS:PubMed and WanFang databases were retrieved for the articles related to unicompartmental knee prostheses and its clinical outcomes.Totally 177 articles were retrieved,and finally 35 eligible articles plus other 4 reports were included after excluding repetitive studies.RESULTS AND CONCLUSION:(1) It has been more than 60 years since the birth of unicompartmental knee prostheses.Despite the difficult in the past,it comes to mature and the survival rate is more than 90％ at 10 years.(2) At present,the most popular prostheses include mobile-bearing (represented by Oxford 3) and fixed-bearing (represented by ZUK and Link).There is no significant difference in clinical outcomes between two designs.However,their differences have been noted in their modes and timing of failures.(3) Aseptic loosening and lateral osteoarthritis progression remain the most common failure modes in unicompartmental knee prostheses.(4) Cementless prostheses and individual unicompartmental knee prostheses based on CT or MRI scan maybe promote the long-term efficacy of unicompartmental knee prostheses.

The procedure of unicompartmental knee arthroplasty has get significant achievement in recent years.Recent studies show that unicompartmental knee arthroplasty for the treatment of unicompartmental osteoarthritis not only has quick rehabilitation,little injury,good post-operative functional outcome,effectiveness costs,but also preserves bone.The survival of UKA prostheses was about 95% at 10 years follow up.With strict patient selection,unicompartmental knee arthroplasty for the treatment of unicompartmental arthritis is preferable.

[Objective]To assess the difference of resurfacing versus nonresurfacing the patella in total knee arthroplasty. [Methods]Studies on comparison between resurfacing and nonresurfacing the patella in total knee arthroplasty were identified.All the randomized controlled trials were included for Meta analysis with Rev Man 4.2 software.[Results]Sixteen eligible randomized controlled trials showed 1922 TKA.The result of meta-analysis indicated that the risk of postoperative anterior knee pain was lower in patellar resurfacing group than in patellar nonresurfacing group within 5 years.But the difference did not exist after 5 years.The combined RR was 0.53,95%CI(0.30,0.94).The risk of reoperation had no significant difference in patellar resurfacing group and patellar nonresurfacing group within 5 years.But 5 years later,the risk of reoperation was lower in patellar resurfacing group than in patellar nonresurfacing group.The combined RR was 0.35,95%CI(0.18,0.66).There was no difference in the mean postoperative knee scores(WMD=0.44,95%CI(-1.22,2.09)).[Conclusion]Patellar resurfacing can reduce the risk of postoperative anterior knee pain within 5 years and the risk of reoperation 5 years later after total knee arthroplasty.There is no difference in the mean postoperative knee scores.More carefully designed randomized controlled trials are required to evaluate the difference of resurfacing versus nonresurfacing the patella in total knee arthroplasty.

[Objective] Posteroanterior weight-bearing radiographs,made with the knee in 45 degrees of flexion while the patient was standing on the homolateral foot,were compared with the weight-bearing anteroposterior radiographs with both knees in full extention,in order to find a more sensitive method to detect knee osteoarthritis.[Methods]Seventeen osteoarthritis knees were radiographed in the weight-bearing anteroposterior view with both knees in full extention and in the weight-bearing posteroanterior view with the knee in 45 degrees of flexion while standing on the homolateral foot.The minimum joint space width of all the radiograph were measured.The data were analysed statistically with SPSS 11.5.[Results]The mean minimum joint space width of the medial compart in extended knee view and standing on the homolateral foot were 4.65 mm?1.44 mm and 2.52 mm?1.69 mm,respectively(P

Objective To explore the indication, to describe the key of operative technique in detail and to summarize the early results in mini-incision and minimally invasive surgery (MIS) total hip arthroplasty (THA) for hip disorders. Methods From Mar. 2003 to Mar. 2005, 43 patients (49 hips) were performed with MIS THA. The mean age of patients was 53.2 years ranging from 22 to 79 years. There were 22 males and 21 females. The average body mass index (BMI) was 23.4 ranging from 17.1 to 30.2. Using the modified postero-lateral approach, MIS THA was performed with cementless prostheses. For comparison, 35 patients (43 hips) were performed with standard THA at the same period. The age and BMI of patients in both groups were similar, but the pattern of disorders was different. The comparative items included preoperative bleeding, operative time, incisional length, postoperative functional recovery, and prosthetic position. Results 31 patients (MIS THA) and 25 patients (standard THA) were followed from 6 to 24 months (mean 13.1 months). No complications occurred in MIS THA. Dislocation appeared in one patient with standard THA at the two days after operation. The length of incision was 9.3 cm (range, 8.7 to 10.5 cm) in MIS group and 16.8 cm (range, 14 to 20 cm) in standard THA group. The difference was significant statistically (P

Objective To assess the effect of IL 1Ra gene transfer on amelioration of symptoms and cartilage injury of osteoarthritis (OA) in rabbit. Methods Thirty New Zealand rabbits were divided into 3 groups. Synovial membrane was harvested from the left knee, and synovial fibroblasts were isolated and cultured. Fibroblasts from each rabbit were traanfected using the retrovirus with either IL 1Ra gene (group 3) or marker gene (group 2) in vitro . OA was induced in the right knee of all rabbits by anterior cruciate ligament transection (ACLT). The autologous cells tranfected with IL 1Ra gene or marker gene were respectively injected into the right knee of group 3 and 2. At the end of 2nd and 4th week, IL 1Ra level in synonival fluid (SF) of the right knee were determined by ELISA. The results were evaluated by grading local pain stimulating response, change of gait, joint swelling, and range of joint motion. The degree of injury to the cartilage was graded by the staining of India ink and pathological examination. Results The IL 1Ra level in the right knee SF of group 3 were 20 16?1 8 ng/ml and 4 82?0 52 ng/ml at the end of 2 and 4 weeks after gene delivery, respectively, while that in the group 2 and group 1 was very low. In IL 1Ra gene transfection group, the symptoms of the joint injury and the degree of cartilage lesion were less severe compared with control group. Conclusion This study showed that IL Ra transfer could raise IL 1Ra level in knee joints, thereby alleviate the symptoms and cartilage injury in experimental osteoarthritis

Objective To explore suppression of chondrocyte apoptosis by IL-1Ra gene transfer to the knees of experimental osteoarthritis (OA).Method ①Thirty New Zealand white rabbits were divided into 3 groups,partial synovectomy of the left knee had been done.Synovial fibroblasts (SF) were isolated and cultured.②Fibroblasts from each rabbit were transduced by using the retrovirus with either IL-1Ra gene (group 3) or marker gene to (group2) in vitro.③ OA was induced in right knee of rabbits by anterior cruciate ligament transection (ACLT).④ The autologous cells transduced with IL-1Ra gene or marker gene were injected into the right knee of group 3 or 2.⑤At the second week and at the forth week,IL-1Ra level in SF was determined by ELISA.⑥Cartilage section were stained for checking histologic changes and chondrocyte apoptosis were determined using TUNEL method.Results The IL-1Ra level in the SF of group 3 were (20.6?1.8)ng/ml and (4.82?0.52)ng/ml after 2 and 4 weeks,after gene delivered respectively,and the IL-1Ra level in the group 2 and group 1 were very lowat both 2 and 4 weeks.Approximately 40% of chondrocytes underwent apoptosis in group 2,whereas apoptosis were inhibited in group 3,only 18% of chondrocytes underwent apoptosis,and 2%~5% of chondrocytes underwent apoptosis in normal joint.Conclusion This study showes that a local increase IL-1Ra level in OA keen joints by intraartilcular injection of IL-1Ra gene transduced synovial cells can suppress articular cartilage chondrocyte apoptosis.

BACKGROUND:MicroRNAs (miRNAs) are widely involved in regulation of physiological processes, such as human development, cel proliferation, differentiation, and apoptosis, angiogenesis and lipid metabolism. MiRNAs also play an important regulating role in the pathological process of femoral head necrosis. At present, the research about the effect of icarin on miRNA expression in glucocorticoid- induced avascular necrosis is stil in the exploratory stage, and the specific targets, possible regulation mechanism and signaling pathway remain unclear.
OBJECTIVE:To explore the effect of icarin on miRNA expression of bone microvascular endothelial cels in steroids-induced human femoral head lesionsin vitro.
METHODS: Bone microvascular endothelial cels in cancelous bone of the femoral head were isolated and harvested in vitro. Icarin preconditioning preceded establishment of models of glucocorticoid-induced bone microvascular endothelial cel injury. Differential expression profiles and transcriptomes in glucocorticoid and normal groups were tested by miRNA microarrays. The most differentialy expressed miR-23b and miR-339 in microarray analysis were further confirmed by real-time quantitative PCR, Meanwhile the effects of icarin on the expression of miR-23b-5p and miR-339-5p were detected.
RESULTS AND CONCLUSION:According to the microarray analysis, one miRNA was up-regulated and four mi RNAs were down-regulated in the glucocorticoid group (fold > 2,P < 0.05). Results of RT-qPCR revealed that miR-23b was down-regulated and miR-339 up-regulated in the glucocorticoid group, which were in agreement with the microarray analysis (P < 0.05). Icarin pretreatment effectively prevented the imbalances of miR-23b expression induced by glucocorticoid (P < 0.01). These findings indicate that Icarin may participate in the pathological process of steroid-induced femoral head necrosis through regulating the expression of miR-23b.

BACKGROUND:At present, there stil remain controversies concerning the choice of tibial slope in unicompartmental knee arthroplasty, and the related biomechanical studies are rare. OBJECTIVE:To find the rational tibial slope in mobile-bearing unicompartmental knee arthroplasty through the results of finite element analysis. METHODS:A finite element model of normal knee was established and validated using the techniques of three-dimensional reconstruction and finite element pre-processing. Then the finite element models of unicompartmental knee arthroplasty with different tibial slopes were established based on the normal knee model. The finite element analyses were conducted after the boundary conditions and loads were unified. RESULTS AND CONCLUSION: The finite element models of unicompartmental knee arthroplasty with different tibial slopes were established successfuly. The results of the finite element analyses indicated that the posteromedial tibial cortical and cancelous bone stress increased gradualy as the posterior slope increasing, as wel as the load distribution and the cartilage contact pressures of lateral compartment. The anteromedial tibial cortical stress increased significantly with the anterior slope. A posterior tibial slope of 0°-7° can be recommended when implanting a mobile-bearing unicompartmental knee arthroplasty.

BACKGROUND: The distal femur resection in total knee arthroplasty is commonly made using a fixed angle relative to an intramedullary rod. Does a fixed distal femur resection angle influence radiographic alignment in primary total knee arthroplasty? OBJECTIVE: To research the femoral mechanical-anatomical angle in Chinese and how it affects the femoral component angle and postoperative mechanical alignment for total knee arthroplasty. METHODS: Totally 109 cases (148 knees) underwent primary total knee arthroplasty. One surgeon used a fixed resection angle of 5° (group A; n=56 cases, 76 knees). The second surgeon adjusted the resection angle according to preoperative coronal alignment, using 5° for neutral/mild varus, 6° for more severe varus, 4° for mild valgus and 3° for severe valgus knees (group B; n=53 cases, 72 knees). Preoperative hip-knee-ankle angle, femoral mechanical-anatomical angle, postoperative hip-knee-ankle angle, femoral component angle and tibial component angle were measured from standing hip-knee-ankle angle radiographs. For postoperative hip-knee-ankle angle, 177°-183° were considered as neutral mechanical axis. For femoral and tibial component angles, the target results were 88°-92°.RESULTS AND CONCLUSION: (1) There was no statistically significant difference between groups in postoperative hip-knee-ankle angle (group A: (178.78±3.57)°, group B: (178.23±2.78)°; P=0.302) and good rate of hip-knee-ankle angle (group A: 62%, group B: 65%). (2) The mean femoral mechanical-anatomical angle was (6.70±1.34)°preoperatively. There was no significant difference in the good rate of hip-knee-ankle angle (hip-knee-ankle angle < 7°:69%; hip-knee-ankle angle ≥7°: 55%; P=0.108) postoperatively. There was a statistically significant difference about good rate of femoral component angle between different femoral mechanical-anatomical angle angles (femoral mechanical-anatomical angle < 7°: 76%; femoral mechanical-anatomical angle ≥7°: 39%; P < 0.01). (3) There was a statistically significant correlation between preoperative femoral mechanical-anatomical angle and postoperative hip-knee-ankle angle (r=?0.42, P < 0.01) and postoperative femoral component angle (r=?0.58, P < 0.01). (4) The mean femoral mechanical-anatomical angle was larger than foreign values. When the resection angle less than femoral mechanical-anatomical angle, the femoral component may tend to be varus which could affect the lower extremity mechanical alignment. For the larger femoral mechanical-anatomical angle, we advise to adjust the resection angle according to measured value preoperatively.