Stress fractures of the proximal tibia metaphysis are rare in the elderly. We present a case of a 65-year old male who developed sequential proximal tibia stress fractures associated with prolonged usage of methotrexate and prednisolone within a span of 18 months. Magnetic Resonance Imaging revealed an incomplete stress fracture involving the medial proximal tibial region. The patient was treated with stemmed total knee arthroplasty (TKA) bilaterally. Stress fractures should be considered in patients with atypical knee pain who have a history of methotrexate and prednisolone usage. TKA is an effective treatment in stress fractures of the proximal tibia.
Fractures, Stress

The purpose of this in vitro study was to evaluate the effect of surface defects and cross-sectional configuration of NiTi rotary files on the fatigue life under cyclic loading. Three NiTi rotary files (K3(TM), ProFile(R), and HERO 642(R)) with #30/.04 taper were evaluated. Each rotary file was divided into 2 subgroups: control (no surface defects) and experimental group (artificial surface defects). A total of six groups of each 10 were tested. The NiTi rotary files were rotated at 300rpm using the apparatus which simulated curved canal (40 degree of curvature) until they fracture. The number of cycles to fracture was calculated and the fractured surfaces were observed with a scanning electron microscope. The data were analyzed statistically. The results showed that experimental groups with surface defects had lower number of cycles to fracture than control group but there was only a statistical significance between control and experimental group in the K3(TM) (p<0.05). There was no strong correlation between the cross-sectional configuration area and fracture resistance under experimental conditions. Several of fractured files demonstrated characteristic patterns of brittle fracture consistent with the propagation of pre-existing cracks. This data indicate that surface defects of NiTi rotary files may significantly decrease fatigue life and it may be one possible factor for early fracture of NiTi rotary files in clinical practice.
Fatigue* ; Fractures, Stress*

Sacral insufficiency fractures (SIFs) are no longer a rare type of fracture in the elderly. To date, SIFs have typically been treated conservatively. Sacroplasty has recently been used in treatment of SIFs, with a good result. In order to solve the problems of sacroplasty, the authors performed a new surgical technique, percutaneous iliosacral screw fixation with cement augmentation, for SIFs. Secure fixation of the screw in osteoporotic bone was achieved and biological bone union was obtained. We present this case with a review of the literature.
Aged ; Fractures, Stress ; Humans

Satisfactory results of unicondylar knee arthroplasty (UKA) have been reported since minimally invasive UKA had been introduced. However, several stress fractures of the tibial plateau, related to instrumentation design, have been reported. We report two cases of periprosthetic stress fractures of the tibial plateau after navigation-assisted unicondylar knee arthroplasties.
Arthroplasty* ; Fractures, Stress* ; Knee*

Fracture of the metal base of tihial components of total knee arthroplasty has heen occasionally reportecl. The most common cause of the failure of the metal hase plate was known to be a fatigue fracture around the screw hole where the strength of the metal hase plate was the weakest. We experienced a case of the fracture of the metal hase plate secondary to the t'racture of the posteromedial corner of the metal tihial condyle which was weakened due to the shoil peg hole for the base plate of MG II implant. Since the proximal portion of the posterior tihial condyle was normally thin, cutting the hone for the base plate made it thinner and wcaker than normal. Therefore stress fracture of the bone occurred and the overlying metal plate was subsequently hroken. From this experience. we concluded that the posterior peg hole may cause unwanted failure of the posteromedial corner of the tibial base plate.
Arthroplasty* ; Fractures, Stress ; Knee*

No abstract available.
Femur Neck* ; Fractures, Stress*

No abstract available in English.
Fatigue ; Fractures, Stress

No abstract available in English.
Fatigue ; Fractures, Stress

There are various factors affecting the fracture of NiTi rotary files. This study was performed to evaluate the effect of cross sectional area, pecking motion and pecking distance on the cyclic fatigue fracture of different NiTi files. Five different NiTi files-Profile(R)(Maillefer, Ballaigue, Switzerland), ProTaper(TM) (Maillefer, Ballaigue, Switzerland), K3(R) (SybronEndo, Orange, CA), Hero 642(R) (Micro-mega, Besancon, France), Hero Shaper(R)(Micro-mega, Besancon, France)-were used. Each file was embedded in temporary resin, sectioned horizontally and observed with scanning electron microscope. The ratio of cross-sectional area to the circumscribed circle was calculated. Special device was fabricated to simulate the cyclic fatigue fracture of NiTi file in the curved canal,. On this device, NiTi files were rotated (300rpm) with different pecking distances (3 mm or 6 mm and with different motions (static motion or dynamic pecking motion). Time until fracture occurs was measured. The results demonstrated that cross-sectional area didn't have any effect on the time of file fracture. Among the files, Profile(R) took the longest time to be fractured. Between the pecking motions, dynamic motion took the longer time to be fractured than static motion. There was no significant difference between the pecking distances with dynamic motion, however with static motion, the longer time was taken at 3mm distance. In this study, we could suggest that dynamic pecking motion would lengthen the time for NiTi file to be fractured from cyclic fatigue.
Citrus sinensis ; Fatigue* ; Fractures, Stress

No abstract available.
Dental Porcelain* ; Fatigue* ; Fractures, Stress*