Internal fixation for bone fractures with rigid metallic plates, screws and pins is a proven operative technique. However, refracture's have been observed after rigid internal fixation with metal plates and plate fixation has been known to cause localised osteopenia under and near the plate. In the present study, resorbable composites comprising a PLA matrix reinforced with iron doped phosphate glass fibres were investigated. Non-woven random mat laminates of approximately 30% and 45% fibre volume fraction (V(f)) were produced, along with unidirectional and 0°-90° samples of approximately 20% V(f). The non-woven composite laminates achieved maximum values of 10 GPa modulus and 120 MPa strength. The 0-90º samples showed unexpectedly low strengths close to matrix value (~50 MPa) although with a modulus of 7 GPa. The UD specimens exhibited values of 130 MPa and 11.5 GPa for strength and modulus respectively. All the modulus values observed were close to that expected from the rule of mixtures. Samples immersed in deionised water at 37°C revealed rapid mechanical property loss, more so for the UD and 0-90º samples. It was suggested that continuous fibres wicked the degradation media into the composite plates which sped up the deterioration of the fibre-matrix interface. The effect was less pronounced in the non-woven random mat laminates due to the discontinuous arrangement of fibres within the composite, making it less prone to wicking. Random mat composites revealed a higher mass loss than the UD and 0°-90° specimens, it was suggested this was due to the higher fibre volume fractions of these composites and SEM studies revealed voidage around the fibres by day 3. Studies of pH of the degradation media showed similar profiles for all the composites investigated. An initial decrease in pH was attributed to the release of phosphate ions into solution followed by a gradual return back to neutral.

The authors conducted a retrospective study on 120 consecutive cases of nasolacrimal duct obstructions (NLDO) in 85 children, operated on by a single surgeon (BF) from January 1988 to July 1992. Mean age at the time of surgery was 5.4 years (1 to 11 years). Seventyseven bicanaliculo-nasal intubations (BCNI) and 43 monocanaliculo-nasal intubations (MCNI) were performed. MCNI were performed using the Fayet-Bernard 'MonoKa' tubing material (FCI, Paris, France). This device permits monocanalicular intubation with meatic fixation by a punctum-plug-like extremity. Among MCNI, 39 were placed into the superior canaliculus. Nine MCNI were indicated because of a true monocanalicular agenesis (inferior canaliculus agenesis in five cases and superior canaliculus agenesis in four cases).Mean follow-up was ten months. Average duration of intubation was seven months for BCNI and 5.1 months for MCNI. BCNI and MCNI resulted in complete resolution of the epiphora in 62.2 and 67.6% of cases respectively.Intermittent tearing was observed post-operatively in 30.1% of BCNI and 23.5% of MCNI. Permanent tearing was present in 7.5% of BCNI and 8.8% of MCNI.Complications associated with BCNI were observed in 20.7% of cases and occurred an average of 96 days post-operatively. These complications included the loss of tubing (I .3Vo), stricturotomies (2.6V0), and non-reducible exteriorization of tubing (16.8%).Complications associated with MCNI were noted an average of 109 days post-operatively in 25.5% of cases. These complications included two cases (4.7%) of pyogenic granuloma, of which one was associated with the loss of the tubing. One case (2.3%) of superficial corneal erosion, eight cases (18.6%) of exteriorization resulting in loss of tubing and one case of intracanalicular migration of the tubing were also observed with MCNI. Functional results obtained with BCNI and MCNI for NLDO are comparable. However, complications associated with MCNI may be anatomically less damaging given the absence of stricturotomy.

The effects of clonidine, a central alpha 2-adrenoreceptor agonist, on haemodynamic and catecholamine changes were assessed during emergence from anaesthesia, a period which is associated with increased sympathetic nervous discharge, hypertension and tachycardia. According to a double-blind randomized design, 32 patients received either clonidine, preoperatively given by oral route (3.5 micrograms.kg-1) and postoperatively by i.v. infusion (0.3 microgram.kg-1.h-1), or a placebo. Perioperative management was similar in both groups. Measurements were made in the recovery room, before starting clonidine or placebo infusions for evaluation of clonidine premedication, and then during infusion as follows: when core temperature reached 37 degrees C; then 2 h, and 6 h later. Prior to starting infusions, mean blood pressure (88 +/- 15 vs 103 +/- 14 mmHg) (11.7 +/- 2.0 vs 13.7 +/- 1.9 kPa), heart rate (67 +/- 8 vs 87 +/- 17 beats.min-1) and plasma norepinephrine levels (462 +/- 393 vs 615 +/- 361 pg.ml-1) were lower in the clonidine group. Only at the latest measurement (6 h after core temperature reached 37 degrees C) did clonidine elicit significant effects. The values during clonidine infusion compared to placebo were at this time: mean blood pressure (73 +/- 10 vs 86 +/- 13 mmHg) (9.7 +/- 1.3 vs 11.5 +/- 1.7 kPa), heart rate (71 +/- 6 vs 93 +/- 13 beats.min-1) and plasma norepinephrine levels (240 +/- 224 vs 451 +/- 111 pg.ml-1). Our results suggest that: 1) preoperative clonidine may improve the haemodynamic profile associated with anaesthetic discontinuation, but 2) i.v. infusion (0.3 microgram.kg-1.h-1) did not prolong this effect during the early postoperative period in the face of the sympathetic nervous discharge of recovery.

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