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Joint destruction caused by aseptic osteonecroses (AONs) is a severe complication in acute lymphoblastic leukemia (ALL). Here, factors were determined that influence the occurrence and clinical course of AON in ALL patients. Clinical data of 121 patients were correlated with the occurrence of AON. Magnetic resonance imaging was performed in patients with bone pain. Areas of AONs were correlated with the clinical course of AON. Ten patients presented with clinical symptoms of AON and 9 of 10 patients were graded as high-risk ALL compared with 46 of 111 patients without AON (X2, P < .05). In 10 ALL patients 66 AONs were identified by MRI. In some patients up to 14 different AON sites were observed. The courses of AONs varied in individual patients, suggesting that necrosis-specific factors might be responsible. A size above 900 mm2 was significantly associated with progressive AON (P < .01). The more intensive treatment regimen in high-risk ALL patients might contribute to the development of AON. The clinical course of AON, however, is determined by necrosis-specific factors such as a large size. These data could help in developing therapeutic strategies for the prevention of progressive AON.

In a retrospective study of resection arthroplasty of the MP joints in rheumatoid arthritis, 23 patients (32 hands, 128 joints) have been followed for 15 to 22 years. Patient satisfaction was high, and all patients had significant pain relief. Active motion of the joints averaged 35^o, ranging from full extension to 35^o of flexion. Ankyloses developed in five hands (13 joints, 10%). Ulnar deviation of more than 15^o occurred in six patients (ten hands, 30%). Over the course of several years a significant remodelling of the joints was to be observed. In six hands (19%) the metacarpal heads became spontaneously restored to ball-shaped geometry. Gross metacarpal resorption was observed in nine hands (30 %), causing significant shortening of the metacarpals. In one-third of patients the final result was rated as good, fair and poor, respectively. Careful patient selection is mandatory. Patients with mutilating arthritis should be excluded from the procedure; rheumatoid destruction of the wrist joint definitely influences the final result.

Stress corrosion cracking of Type 304 stainless steel has been studied with fracture-mechanics-type standard 25.4-mm-thick compact tension specimens in simulated boiling-water reactor environments at 289°C and 8.3 MPa. Tests were performed with either constant or cyclic loading. The latter tests used a positive sawtooth waveform with an unloading time of 1 or 5 s, a load ratio R (minimum load to maximum load) of 0.2 to 0.95, and a frequency f of 8 × 10−4 to 1 × 10−1 Hz. Crack lengths and crack growth rates were determined by the compliance method; crack mouth opening displacement was measured with in-situ clip gauges. Fractography was used to examine the mode of cracking and to confirm the compliance method for crack length determination. The test environments were high-purity deionized water with 0.2- to 8-ppm dissolved oxygen, and water with 0.2-ppm dissolved oxygen and 0.1-ppm sulfate (as H2SO4). Two heats with a carbon content of 0.06 wt percent were investigated in solution-heat-treated and furnace-sensitized conditions. Degree of sensitization varied from ∼0 to 20 C/cm2 as measured by the electrochemical potentiokinetic polarization method. The first heat was tested in water with 0.2- and 8-ppm dissolved oxygen and with 0.2-ppm dissolved oxygen and 0.1-ppm sulfate. The loading conditions encompassed the range f=8×10−2 to 8 × 10−4 Hz, Kmax=28 to 72 MPa•m1/2, and R = 0.95. Under these conditions, the crack growth rates were ∼0 to 3 × 10−9 m/s. The effects of water chemistry transients which produced changes in the concentration of dissolved oxygen or sulfate in the environment were also investigated. The second heat was tested in water with 8-ppm dissolved oxygen. The influence of load ratio and frequency was investigated over the range R = 0.5 to 1.0 and f = 1 × 10−1 to 2 × 10−3 Hz, at maximum stress intensity Kmax = 28 to 38 MPa•m1/2. Under these conditions, crack growth rates varied from 1 × 10−10 to 3 × 10−9 m/s. Crack growth rate increased significantly at low R values. However, the growth rate at R = 0.95 was not significantly different from that under constant load. Correlation of the crack growth rate data with crack-tip strain rates is discussed.