Screw plugs have been reported to increase the fatigue strength of stainless steel locking plates. The objective of this study was to examine and compare this effect between stainless steel and titanium locking plates. Custom-designed locking plates with identical structures were fabricated from stainless steel and a titanium alloy. Three types of plates were compared: type I unplugged plates; type II plugged plates with a 4 Nm torque; and type III plugged plates with a 12 Nm torque. The stiffness, yield strength, and fatigue strength of the plates were investigated through a four-point bending test. Failure analyses were performed subsequently.Objectives
Methods
Hip fractures have significant excess mortality, but it is unknown how long excess mortality persists. Our study was to explore the short and long term excess mortality after hip fractures, assess the impact of hip fracture on excess mortality and estimate the population attributable risk proportion (PARP) of risk factors for excess mortality. A total of 216 elderly with first time low trauma hip fracture admitted to NTUH were age and sex matched with 215 elder patients from Geriatric Department of the same hospital. All 63 covariates associated with mortality were analyzed using COX regression model. The survival status of these subjects was followed through National Death Registry for 60 months.Backgrounds
Methods
Functional deficient of the little finger flexor digitorum superficialis (FDS-V) is known to be present in our population. The aim of this study is to evaluate the prevalence of the absence of FDS-V function in the Hong Kong Chinese population. The association between FDS-V absence and various variables (age, gender, hand dominance, occupation, smoking status, plamaris longus absence) were evaluated. The effects on the grip power due to FDS-V absence were analyzed. The anatomical variations were studied by cadaveric study. The clinical and anatomical variations were correlated by MRI study. 152 adult Chinese men and women from age 18 to 65 were recruited randomly. Subjects with congenital abnormalities, history of hand injury, history of upper limb surgery or underlying neuromuscular diseases were excluded. This study has 3 different parts. The first part is a clinical survey to determine the prevalence of the absence of FDS-V function by both the standard test and the modified test. The second part is a cadaveric study to determine the anatomical variations of FDS-V tendon by cadaveric dissection. The third part of this study is to correlate the clinical findings with MRI study. Total 152 subjects were recruited with 51 male and 101 female, average age 37.6. The prevalence of the absence of FDS-V function by the standard test was 40.1% for right hand and 37.5% for left hand (38.8%). The prevalence of the absence of FDS-V function by the modified test was 9.2% on the right hand and 9.9% on the left hand (9.54%). The absence of FDS-V function was found more common to be bilateral than unilateral. This was found that 68.6% were bilateral by the standard test and 61% were bilateral by the modified test. The associations of functional FDS-V absence with various variables were insignificant. The effects of various variables on the grip power were analyzed using the multiple linear regression. Gender was1he only variable that had significant effects on the grip power for both the right and left hand. On either hand, the absence of Palmaris longus tendon and the absence of the FDS-V function had no significant effects on the grip power. Cadaveric study showed that the little finger FDS tendon was present in all 10 cadaveric hands. Abnormal muscle or tendon interconnection was not found. MRI study showed that there was hypoplastic tendon in subjects with absent FDS-V function. The prevalence of the absence of FDS-V function in the Hong Kong Chinese population was 38.8% by the standard test and 9.54% by the modified test. The absence of little finger FDS function has no significant effects on the functional status as quantified by the grip power. We can postulate that patients with little finger FDS tendon injury can have normal range of motion and hand function if the FDP tendon is intact.
Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone. We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.
