[Association between occupational hazard exposures and small airway function among middle-aged and elderly people].

Objective: To investigate the association between occupational hazard exposures and small airway function among middle-aged and elderly people. Methods: From July to December in 2015, a multistage cluster random sampling method was used to select 3 600 residents aged 40 years old and above from 6 chronic obstructive pulmonary disease surveillance points in Jiangsu province. A cross-sectional survey was conducted to collect relevant information. Multivariable linear regression model was performed to determine the relationship between occupational hazard exposures and small airway function. Results: A total of 3 347 participants were included in the final analysis, and 44.6% of participants had been exposed to occupational hazard exposures. Compared with participants without the exposure history of occupational hazards, the significantly lower post-bronchodilator FEF50%, FEF75% and MMEF levels were observed in those with the exposure history of occupational hazards (ß=-82.74, -55.43 and -91.57, respectively). Post-bronchodilator FEF75% and MMEF (ß=-51.78 and -79.47, respectively) in the participants with the exposure history of occupational dust and post-bronchodilator FEF50%, FEF75% and MMEF (ß=-96.84, -32.87 and -75.72, respectively) in the participants with the exposure history of occupational harmful gas all showed a lower level. Post-bronchodilator FEF75% was negatively associated with occupational hazard exposures in males (ßmale=-91.65 vs. ßfemale=-27.21, P for interaction=0.022). Conclusions: The small airway function is worse in the middle-aged and elderly population with the exposure history of occupational hazards, and it is more significant in the male population.

Relationship between medial plica and medial femoral condyle--a three-dimensional dynamic finite element model.

BACKGROUND: Many researches reported that the pathologic medial plica impinges on the facing medial femoral condyle during knee motion and leads to erosive changes of the articular cartilage. The purpose of this study was to construct a simplified three-dimensional dynamic finite element human knee model to evaluate the dynamics behaviour between different types of medial plicae with the facing medial femoral condyles during knee motion. METHODS: A three-dimensional dynamic finite element model composed of femur, tibia, covering cartilage and medial plica was developed. The kinematics of this simulation model was verified by previous findings during arthroscopic examination. The validated model was used to investigate and compare the magnitudes of the cyclic pressures acting on the cartilage of the medial femoral condyles by three different types of medial plicae with various Young's moduli. FINDINGS: All types of plicae remained in contact with the medial femoral condyles and shifted medially when the knees moved from extension to flexion. The contact pressures were positively correlated with the Young's moduli of the medial plicae. During the whole range of motion, the maximum contact pressures of all simulation scenarios occurred when the knees moved beyond 50° of flexion. When the Young's moduli of medial plicae were set greater than 60 MPa, all types of medial plicae would elicit contact pressures greater than 10 MPa on the medial femoral condyles. INTERPRETATION: The close relationship and possible high contact pressure between fibrotic medial plica and medial femoral condyle during knee motion might be a cause of cartilage damage on the medial femoral condyle and warrants further investigation.

Arthroscopic medial release for medial compartment osteoarthritis of the knee: the result of a single surgeon series with a minimum follow-up of four years.

The outcome of arthroscopic medial release of 255 knees in 173 patients for varying grades of osteoarthritis involving the medial compartment is reported. All operations were performed by a single surgeon between January 2001 and May 2003. The Knee Society score for pain and the patient's subjective satisfaction were used for the outcome evaluation. Overall, satisfactory outcome was reported for 197 knees (77.3%) and the mean Knee Society score for pain improved from 17.6 (95% confidence interval, 16.7 to 18.5), pre-operatively to 39.4 (95% confidence interval, 37.9 to 41.1) (p < 0.001). There were minor manageable complications of persistent effusion in 16 knees and prolonged wound discomfort in 11. In total, 15 of the 21 knees with poor results were converted to total knee replacements and two other patients (three knees) were offered this option after a mean period of 16 months. Based on these observations arthroscopic medial release is an effective treatment for osteoarthritis of the medial compartment of the knee joint and can be expected to reduce the pain in the majority of patients for at least four years post-operatively.

Use of Wagner cementless self-locking stems for massive bone loss in hip arthroplasty.

OBJECTIVE: To assess the use of Wagner cementless self-locking stems for massive bone loss in hip arthroplasty. METHODS: 22 patients with severe proximal femoral bone loss either due to prosthetic loosening or comminuted fracture were treated by Wagner cementless self-locking revision stems between November 1993 and June 1995. RESULTS: Radiographic evidence of early bony incorporation was found by 1 month in most cases. At a mean follow-up of 7.1 years, the mean Harris hip score increased from 30 to 84 points. It was less than 80 points in 4 patients, 2 of whom experienced severe thigh pain due to marked progressive subsidence of the stems (by 13 mm and 20 mm), which were revised 2 and 3 years later respectively. CONCLUSION: Implantation of a Wagner cementless self-locking revision stem provided satisfactory results for 82% of patients. Hence, in some difficult conditions, this device is a good choice of management.

Effects of a cane on floor reaction force and center of force during gait.

In comparative studies of various gait patterns of 20 healthy subjects who used a cane, the vertical reaction forces and the center of force on the foot were measured and recorded by a force recording and analyzing device. The results indicated that when a cane was used in the ipsilateral hand, the center of force did not shift significantly compared with normal gait. When a cane was used in the contralateral hand, the center of force shifted medially compared with normal gait. In analysis of the vertical floor reaction force acting on the foot, the most efficient way to use a cane was to control the pacing so that the tip of the cane and the foot touched the ground simultaneously. By doing so, the cane could share as much as 34.3% of force at heel strike, 25.3% at midstance, and 29.7% at toeoff of the stance phase of the gait cycle. When prescribing use of a cane for a patient with varus gonarthritis, the patient should be instructed to use the cane in the ipsilateral hand so as not to shift the center of force medially; for a patient with valgus gonarthritis, the cane should be used in the contralateral hand to shift the center of force medially. Patients should be taught to control pacing so that the tip of the cane and the foot touch the ground simultaneously.

Closed division of the flexor tendon sheath for trigger finger.

Closed tenotomy was used to treat triggering of the fingers and thumb in 54 patients. In 56 digits the method was successful; in seven it was a simple matter to proceed to open tenotomy. With experience, the closed procedure can be completed within minutes without risk of damaging the digital nerves.