ABSTRACT
BACKGROUND: Distal radius fractures are often accompanied by the ulna styloid process fractures, and the treatment of the ulna styloid process fracture is disputed in clinic. Manipulative reduction and splint fixation is a common method to treat such diseases. The mechanism of intervention on ulnar styloid process is difficult to obtain in the corpse mechanics experiments. In recent years, the finite element analysis method has been widely used in the field of orthopedics, which has opened up a way for the study of orthopedic disease. OBJECTIVE: To explore the biomechanical mechanism of splint intervention on ulnar styloid fracture by finite element analysis, and to provide the basis for clinical treatment choice. METHODS: A three-dimensional finite element model of normal wrist joint was established based on the forearm and wrist CT images of a healthy volunteer. The validity of the model was verified by comparing with the experimental data in the literature. On this basis, four wrist joint finite element models with and without splint fixation for ulnar styloid type I and type II fractures were established. Under axial compression, lateral extension, pronation and supination working conditions, the changes of the relative displacement of the distal radioulnar joint and the ulnar styloid fracture broken end were analyzed. RESULTS AND CONCLUSION: (1) A three-dimensional finite element model of normal wrist joint was established and validated, and the other four models were established based on this model. (2) In pronation and supination conditions, the relative displacement values of the ulnar and radial joints in the ulnar styloid type I and II fracture models were greater than those in the normal wrist joint model, and the displacement was smaller in the type I fracture model than in the type II fracture model; the displacement was significantly reduced after the intervention on the two fracture models by the splint. (3) In the lateral tension, pronation and supination conditions, the displacement values of the ulnar styloid fracture end in the ulnar styloid type I fracture model were smaller than in the type II fracture model, and the displacement values were significantly reduced after the intervention by the splint. Under the remaining conditions, the change of the above values was not obvious. (4) In conclusion, the stability of distal radioulnar joint became worse after ulnar styloid fracture, and the stability of distal radioulnar joint after type I fracture was less than that after type II fracture. As an elastic fixation method, splint can increase the stability of the wrist ulnar column during the treatment.
ABSTRACT
<p><b>BACKGROUND</b>High peritoneal transport status was previously thought to be a poor prognostic factor in peritoneal dialysis (PD) patients. However, its effect on diabetic nephropathy PD patients is unclear in consideration of the adverse impact of diabetes itself. The purpose of this study was to investigate the influence of peritoneal transport characteristics on nutritional status and clinical outcome in diabetic nephropathy patients on PD.</p><p><b>METHODS</b>One hundred and two diabetic nephropathy patients on PD were enrolled in this observational cohort study. According to the initial peritoneal equilibration test result, patients were divided into two groups: Higher transport group (HT, including high and high average transport) and lower transport group (LT, including low and low-average transport). Demographic characteristics, biochemical data, dialysis adequacy, and nutritional status were evaluated. Clinical outcomes were compared. Risk factors for death-censored technique failure and mortality were analyzed.</p><p><b>RESULTS</b>Compared with LT group (n = 37), serum albumin was significantly lower and the incidence of malnutrition by subjective global assessment was significantly higher in HT group (n = 65) (P < 0.05). Kaplan-Meier analyses showed that death-censored technique failure and mortality were significantly increased in HT group compared with that in LT group. On multivariate Cox analyses, higher peritoneal transport status and lower residual renal function (RRF) were independent predictors of death-censored technique failure when adjusted for serum albumin and total weekly urea clearance (Kt/V). Independent predictors of mortality were advanced age, anemia, hypoalbuminemia, and lower RRF, but not higher peritoneal transport status.</p><p><b>CONCLUSIONS</b>Higher peritoneal transport status has an adverse influence on nutrition for diabetic nephropathy patients on PD. Higher peritoneal transport status is a significant independent risk factor for death-censored technique failure, but not for mortality in diabetic nephropathy patients on PD.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Biological Transport , Cohort Studies , Diabetic Nephropathies , Metabolism , Therapeutics , Kidney , Metabolism , Pathology , Nutritional Status , Peritoneal DialysisABSTRACT
Objective To discuss the possibility for regeneration of knee joint with normal function under bionics biomechanical environment. Methods Seven normal rabbits with two metal frames respectively mounted on their femur and tibia of single (right) side leg by two threading pins of 1.5 mm diameter were used. Then the external artificial joints, containing two four-bar-linkage inside and outside of the knee to simulate motion trajectory of the joint in sagital plane were connected with the two preset fixed frames before osteotomy. The arthro-cartilage of the knee joint, crucial ligaments, semi-lunar fibro-cartilages, and partial under-cartilage-osseous intra articular capsule were cut off during osteotomy, with the patella, sesamoid bones remained intact. Insertion sites of muscle tendons were not invaded as far as possible, and capsules with ligaments outside were kept complete when the incision wound was closed by suture. The rabbits could move freely after osteotomy. The range of motion (ROM) of the knees in sagital plane and bony gap between the femur and tibia were measured by X-Ray films during the fracture healing after osteotomy. Results External artificial knee joints were successfully installed on right legs of 6 rabbits among the seven. The rabbits moved freely after osteotomy under the control of minimal invasive external artificial joint in bionics trajectory. The average angles between femoral shaft and tibial shaft at the 1st week after osteotomy were from (144.7±15.62)° in extremely flexed position to (44.2±25.77)° in extremely extended position, with ROM of (100.5±29.03)°. At the 12th week, the average angles were from (139.4 ± 12.92)° in extremely flexed position to (40.4±22.04)° in extremely extended position, with ROM of (99.0±23.39)°. No significant differences were displayed in flexed/extended position and ROM between the 1st and 12th week, with the bony gaps of the knees still existed but decreased significantly from (4.03±1.84) mm at the 1st week to (2.32±1.05) mm at the 12th week. In contrast, bony gaps of the opposite knees were not changed significantly, which were (1.27±0.22) mm on average. At the end of 16th week after osteotomy, the external artificial joints were removed. Newly born cartilage, with white color and smooth surface, were covered at lower end of the femur and upper end of the tibia. Typical trochlear surface appeared at the front side of regenerated cartilage corresponding to the posterior surface of the patella. And the regenerated fibro-bundle linkage similar with ligament, which started from bony structure of regenerated lower end of the femur and inserted into regenerated upper end of the tibia, was observed in each rabbit. At the 25th week, the average angles between femoral shaft and tibial shaft were from (148.3 ± 4.75)° in extremely flexed position to (48.30±17.57)° in extremely extended position, with ROM of (100.0±20.80)°. In the opposite (left) leg, the average angles between femoral shaft and tibial shaft were from (148.3±7.5)° in extremely flexed position to (21.6±9.09)° in extremely extended position, with ROM of (126.7±6.88)°, and the average bony gap of the knees after osteotomy was (1.4±0.59) mm, while that of the opposite (left) knees was (0.92±0.35) mm. Conclusions The external artificial joint with bionics trajectory could reserve the space for regeneration of rabbit knee joint by providing motion modeling environment, and proved the stress adaption during fracture healing. The present results indicated that regeneration of the knee joint after intra-capsular osteotomy in bionics biomechanical environment was possible.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the clinical effects of diaplastic external fixator on the treatment of unstable fractures of distal radius.</p><p><b>METHODS</b>A clinical data of 60 patients with unstable fractures of distal radius admitted to Wangjing Hospital from August 2005 to September 2009 were retrospectively analyzed with the paired design. According to the paired design, 60 patients were equally divided into two groups (internal fixation group and external fixation group), which were respectively treated with open reduction and steel plate internal fixation (internal fixation group) or closed reduction and external fixation (external fixation group), including 8 males and 52 females, with an average age of 60.27 years ranging from 34 to 85 years. Left side was in 33 cases and right side was in 27 cases. All fractures were closed and caused by hand supporting when falling down. According to AO classification, type A3 was in 22 cases, type B2 was in 4 cases, type B3 was in 2 cases, type C1 was in 20 cases, type C2 was in 8 cases, type C3 was in 4 cases. Palmar flexion, dorsiflexion, radial deviation, ulnar deviation, pronation, supination, grip strength, radial angle, radial length, volar tilt were observed before and after operation.</p><p><b>RESULTS</b>All the patients were followed up from 12 to 18 months with an average of 15.4 months. The radial length was (4.85 +/- 2.75) mm,volar tilt (14.66 +/- 10.77) degrees, radial angle (7.90 +/- 4.70) degrees in the external fixation group,while those were (4.29 +/- 1.53) mm, (14.39 +/- 5.01) degrees, (6.19 +/- 3.15) degrees in the internal fixation group, but with no statistical significance (P>0.05). Function comparison of internal and external fixation group, P-value of every function is more than 0.05 or equal to 0.05, with no statistical significance except for supination and radial deviation. The functions of wrist joints were evaluated according to Batra scoring system at 1 year after operation. The average radiological scores of external fixation group was 86.27,in which 15 cases were excellent, 11 good, 1 fair,3 poor,while the average functional scores was 94.93, and all the cases were excellent. The average radiological scores of internal fixation group was 91.27, 16 cases were excellent, 12 good, 2 fair, while the average functional scores was 94.23, in which all the cases were excellent.</p><p><b>CONCLUSION</b>Compared with the open reduction and steel plate fixation, the unstable fractures of distal radius treating by diaplastic external fixator can be achieved a similar result, with no statistical significance.</p>