BACKGROUND:Valgus-varus constrained polyethylene insert is selected in strict accordance with the principle of“to obtain reliable stability using minimum restriction”. The stability of the prosthesis is elevated, but the restriction is not increased.
OBJECTIVE:To retrospectively analyze the application experience of constrained polyethylene insert in valgus and varus instability of primary total knee arthroplasty for older patients and to summarize the indications and clinical effects of this kind of implements.
METHODS:From March 2010 to March 2012, a total of 70 patients combined valgus and varus malfomation who accepted primary total knee arthroplasty were enrol ed in this study, including 56 varus patients (averagely 15°-30°) and 14 valgus patients (averagely 10°-20°). Constrained polyethylene insert was performed in 23 patients (25 knees) who stil had remaining unilateral valgus or varus<6 mm (18 patients were varus instability and 7 patients were valgus instability) when finished operation of standard osteotomy and soft tissue balancing. The bone cement knee prostheses in 23 cases were purchased from Smith&Nephew. The stem implant was not used in al cases. Cement or autografts were used in 11 valgus knees to fil the bone defects.
RESULTS AND CONCLUSION:Patients were fol owed up for 2 years on average (18-42 mouths). The knee pain symptoms of al cases disappeared. The joint stability was obviously improved. The lower limb power lines were correct. The Knee Society Score scores were improved from an average of 39.4 points preoperation to an average of 88.5 points postoperation. Al cases did not need the protection of knee braces. The maximum degree of flexion was 110°(96°-130°). The satisfaction degree of 36-Item Short Form Health Survey was 98%. No dislocation or infection happened. Results indicated that constrained polyethylene insert could be applied in the cases of less than 6 mm valgus and varus instability when finished operation of standard osteotomy and soft tissue balancing in total knee arthroplasty for older patients. This kind of implements can preserve bone mass, simplify operational process and have good clinical outcome in a short period.

BACKGROUND: Common complication of traditional joint replacement is hip joint dislocation and large head joint implant can effectively solve this problem. OBJECTIVE: To investigate the preliminary efficacy of large head metal-on-metal implants for patients undergoing total hip arthroplasty. DESIGN, TIME AND SETTING: Prospective cohort study. The patients were selected from Department of Joint Surgery, Xinjiang Hospital of Traditional Chinese Medicine between February 2007 and January 2008. PARTICIPANTS: A total of 65 patients (71 hips) undergoing large head metal-on-metal implantation in Xinjiang Hospital of Traditional Chinese Medicine were selected, including 21 females and 44 males with an average age of 54.6 years (ranging 19 to 77 years). Of them, there were 28 cases of necrosis of the femoral head, 24 of hip osteoarthritis, 9 of femoral neck fracture and 4 of acetabular dysplasia. METHODS: According to age, sex, cause of disease and preoperative joint function, the patients were divided into traditional prosthesis (n=30, 33 hips, metal-on-polyethylene implant) and large head M-O-M group (n=35, 38 hips, ASR/XL prosthesis, DePuy, Motech, Warsaw, IN, USA). MAIN OUTCOME MEASURES: The pre and postoperative Harris scores for the hip, range of motion, periprosthetic radiolucency, leg-length inequality and complications were recorded and compared. RESULTS: All patients were followed-up. The traditional group was followed up for 20 months (ranging 13-28 months), and the large head M-O-M group was followed up for 17 months (ranging 10-26 months). The mean Harris score was 89 points (ranging 59-98) in traditional group, and 94 points (ranging 71-100) in large head M-O-M group (P=0.014). The range of motion of hip was improved, and the large head M-O-M group (34?) was superior to traditional group (26?, P=0.004) at 6 months after surgery; the range of motion was improved 27? in traditional group and 37? in large head M-O-M group (P=0.009) over 1 year of follow up. The leg-length inequality was 4 mm (2-11 mm) in large head M-O-M group and 7 mm (5-16 mm) in traditional group (P=0.005). Both groups exhibited periprosthetic radiolucency (≤1 mm, 2 cases in traditional group and 3 cases in large head M-O-M group). One patient in the traditional group suffered dislocation. CONCLUSION: The large head M-on-M implants in total hip arthroplasty has excellent short-term effects on patients compared with traditional prosthesis. They offer the more stability and better restoration of hip articulation function and biomechanical reconstruction.

Objective:To observe the effects of T-2 toxin on expression of hepatocyte growth factor (HGF) and HGF receptor (C-Met) in articular cartilage and epiphyseal cartilage of rats under low selenium condition.Methods:Twenty-four healthy male SD rats weighted 60-80 g were randomly divided into conventional diet group (selenium content of 101.5 μg/kg) and low-selenium diet group (selenium content of 1.1 μg/kg), with 12 rats in each group. After 30 days of feeding, the conventional diet group was further divided into conventional group and T-2 toxin group (100 μg·kg -1·d -1), and the low-selenium diet group was further divided into low-selenium group and low-selenium+T-2 toxin group (100 μg·kg -1·d -1), with 6 rats in each group. After 30 days of feeding, the rats were sacrificed and the cartilage of knee joint was taken, the morphological changes of knee articular cartilage and epiphyseal cartilage were observed by HE staining under light microscope. Immunohistochemical method was used to detect the expression of HGF and C-Met in knee articular cartilage and epiphyseal cartilage, and positive expression rates of HGF and C-Met were calculated. Results:Under light microscope, chondrocytes of articular cartilage and epiphyseal cartilage in low-selenium+T-2 toxin group were sparse, and the necrosis and structural area were found in the deep layer, and the extracellular matrix of chondrocytes in the region was degraded and light stained, and proliferating granulation tissue was visible nearby. The positive expression rates of HGF in articular cartilage [(21.97 ± 6.90)%, (49.41 ± 8.24)%, (76.39 ± 5.88)%] and epiphyseal cartilage [(23.36 ± 12.49)%, (58.43 ± 14.48)%, (66.59 ± 10.83)%] of rats in low-selenium, T-2 toxin and low-selenium+T-2 toxin groups were higher than those in conventional group [(9.13 ± 6.01)%, (11.14 ± 4.67)%, P < 0.05]. The positive expression rates of C-Met in articular cartilage [(25.34 ± 7.53)%, (58.21 ± 12.54)%, (81.46 ± 7.89)%] and epiphyseal cartilage [(35.21 ± 4.71)%, (40.84 ± 2.03)%, (49.41 ± 6.29)%] of rats in low-selenium, T-2 toxin and low-selenium+T-2 toxin groups were higher than those in conventional group [(11.21 ± 5.11)%, (12.12 ± 4.71)%, P < 0.05]. Conclusion:T-2 toxin may affect the expression of HGF and C-Met in articular cartilage and epiphyseal cartilage of rats under low selenium condition.

Objective:To explore the risk factors for urethral stricture after transperineal anastomotic urethroplasty (TAU) by retrospectively analyzing patient data and to develop a nomogram to predict the risk of recurrence before the surgery.Methods:Clinical data of patients who underwent TAU because of post-traumatic urethral stricture from January 2016 to December 2017 in West China Hospital, Sichuan University were reviewd. A total of 78 patients were included in the retrospective analysis, with 13 of them having recurrence. The patients in the recurrence group had a median age of 49.8 and 76.9% (10/13) of them had membranous urethral stricture. The proximal urethra end was located above the superior margin of the pubic ramus (higher stricture site) in 53.8%(7/13)of patients in the recurrence group and the length of the stricture measured in the operation was (2.19±0.22) cm. In the non-recurrence group, the median age was (44.8±13.6) years old, 58.5% (38/65) of them had membranous urethral stricture, 21.5% (14/65) had higher stricture site, and the length of the stricture was (2.03±0.11) cm. Both univariate and multivariate logistics analyses were performed to evaluate the risk factors of recurrence of urethral stricture 5 years after surgery. The nomogram was built based on the multivariate logistics analysis. The Concordance Index (C-index), Receiver Operating Characteristic(ROC) curve and Calibration curve were used to evaluate the nomogram.Results:Univariate logistics analysis showed that higher stricture site, history of urethral dilation, smoking, diabetes and total serum protein may be associated with recurrence after surgery. Multivariate logistics analysis further confirmed that higher stricture site ( OR=34.64, 95% CI 3.71-754.53), history of urethral dilation( OR=13.15, 95% CI 1.27-210.00), smoking ( OR=13.75, 95% CI 2.15-166.05) and diabetes ( OR=64.98, 95% CI 3.80-1957.60) were independent risk factors for recurrent urethral stricture while higher total serum protein before surgery was related to lower recurrence risk ( OR=0.78, 95% CI 0.62-0.93). A nomogram was built based on the results. The C-index of the nomogram was 0.923(95% CI 0.908-0.938), the area under curve (AUC) was 0.923 (95% CI 0.855-0.991), and the Brier Score was 0.079. Conclusion:Higher stricture site, history of urethral dilation before surgery, smoking, diabetes and lower total serum protein before surgery are associated with higher recurrence TAU of post-traumatic urethral stricture patients. With the nomogram developed, prediction of the risk of recurrence could be achieved prior surgery.

Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.