The Low-Energy Neutral Imager (LENI).

To achieve breakthroughs in the areas of heliospheric and magnetospheric energetic neutral atom (ENA) imaging, a new class of instruments is required. We present a high angular resolution ENA imager concept aimed at the suprathermal plasma populations with energies between 0.5 and 20 keV. This instrument is intended for understanding the spatial and temporal structure of the heliospheric boundary recently revealed by Interstellar Boundary Explorer instrumentation and the Cassini Ion and Neutral Camera. The instrument is also well suited to characterize magnetospheric ENA emissions from low-altitude ENA emissions produced by precipitation of magnetospheric ions into the terrestrial upper atmosphere, or from the magnetosheath where solar wind protons are neutralized by charge exchange, or from portions of the ring current region. We present a new technique utilizing ultrathin carbon foils, 2-D collimation, and a novel electron optical design to produce high angular resolution (≤2°) and high-sensitivity (≥10-3 cm2 sr/pixel) ENA imaging in the 0.5-20 keV energy range.

The timing of amputation for lower limb trauma.

We reviewed 35 patients who had an amputation following the failure of treatment for severe lower limb trauma. Seven of the amputations were for ischaemia, within one month of injury; 13 were between one month and one year for infection complicating loss of wound cover in un-united fractures; and 15 were later than one year after injury, mainly for infected non-union. The latter group of patients had had an average of 12 operations and 50 months of treatment, including eight months in hospital. We used a new limb injury score based on damage to the individual tissue elements; this indicated that, even in the absence of neurovascular injury, the presence of severe damage to skin, bone and muscle, with wound contamination, particularly in the lower tibia, had a poor prognosis. We therefore recommend, to avoid multiple operations, with prolonged hospitalisation and suffering, that these patients should have early independent review by orthopaedic and plastic surgeons with the aim of establishing an accurate prognosis for the salvage of a useful limb.

Capsular distension and intracapsular pressure in subcapital fractures of the femur.

It has been shown that raised intracapsular pressure causes avascular necrosis of the femoral head in experimental animals, but the relevance of this to clinical fractures of the femoral neck is controversial. We have studied 19 patients with intracapsular fractures of the femoral neck by pressure measurement and by ultrasonography to demonstrate capsular distension. The intra-articular pressure in Garden Grade I and II fractures averaged 66.4 mmHg with a maximum of 145 mmHg. In 10 Garden Grade III and IV fractures the average pressure was 28 mmHg with a maximum of 65 mmHg. Most of the recorded intracapsular pressures were high enough to have caused possible vascular embarrassment, and it is suggested that early decompression of the haemarthrosis should be considered.

Immediate operative fitting of upper limb prosthesis at the time of amputation.

Three patients are described--2 with an above-elbow amputation and 1 with a through-wrist amputation--in whom a temporary prosthesis was applied on the operating table and in all of whom function was rapidly established. The patients did not become one-handed, with the result that they have all continued to wear their prosthesis throughout their working hours and use their artificial hand for all everday functions. The value of this technique in making the patient accept the prosthesis and therefore to make full use of it suggests that this procedure should be more widely applied in patients who require upper limb amputation.