A cross-sectional study was carried out to obtain data on the bone mineral density status of a group of neurofibromatosis-1 patients with spinal deformities, and to search for possible accompanying changes in the bone mineral turnover. Neurofibromatosis-1 is a heredofamiliar disorder that is associated with a variety of skeletal anomalies (mostly spinal deformities) in 10-50% of patients. Intraoperatively, a poor vertebral bone quality has been observed. Efforts have been made to identify factors preventing curve progression, to optimize operational planning and to explain the pathomechanism. As part of the preoperative evaluation, dual-energy X-ray absorptiometry was used to assess the bone mineral density of the lumbar spine in 12 patients with neurofibromatosis-1, supplemented by laboratory blood/urine investigations. A significant decrease in bone mineral density of the lumbar spine was measured. An inverse relation was suggested between the severity of scoliosis and the lumbar spine Z-scores. No pivotal alterations were identified in the laboratory measurements. The bony tissue abnormality observed intraoperatively in neurofibromatosis-1 patients may be described as a diminution of the axial bone mineral density. The biochemical parameters do not support the presence of hyperparathyroidism, renal disorders or other associated diseases influencing the bone mineral turnover. The evaluation of bone mineral density in the course of the preoperative planning is proposed in neurofibromatosis-1; the exact background and the role of a possible osteoporosis in the prognosis remain to be elucidated.

Object. In 10 to 50% of cases with neurofibromatosis, skeletal disorders are present, mainly as various deformities of the spine. These deformities can be divided into dystrophic and nondystrophic groups depending on the absence or presence of bone dystrophy. The nondystrophic curves are highly similar to those in idiopathic scoliosis, whereas the dystrophic curves are manifested early and, by progressing inexorably, may lead to neurological symptoms. In this article the authors report on a series of 12 patients (11 with dystrophic and one with nondystrophic deformities) who underwent surgical treatment. Methods. In the case with a nondystrophic curve, posterolateral instrumentation-assisted fusion was performed. A curvature correction of 70% was achieved in the frontal plane, and at the 2-year follow-up examination neither bone dysplasia nor pseudarthrosis was observed. In the cases with dystrophic curves, preoperative traction for 3 weeks was applied; anterior surgical release was then performed, as was two-stage posterior instrumentation-assisted fusion. In the cases of thoracic kyphoscoliosis in which this treatment protocol was performed, the mean scoliosis correction was 66%, whereas the mean decrease in kyphotic angle was 34.5°. In the cases with thoracolumbar and lumbar curves, the mean correction in the frontal plane was 69.8°, whereas the mean preoperative lumbar kyphosis of 42° was corrected to a mean lordotic angle of 23°. Postoperatively, no hook dislocation was detected. A neurological complication was observed in one case. Conclusions. The surgical treatment of dystrophic curves always included 360° fusion and the use of a tibial corticocancellous graft, which must be placed on the concave side of the curve in the frontal plane, the graft thereby providing biomechanical support.

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The effect of morphine was examined on the circular muscle of guinea pig ileal segments in vitro, with special regard to its interaction with enteric nitric oxide (NO) releasing neurons. In the presence of atropine (10^–6 M), morphine (10^–6 M) caused tonic contraction (approximately 7% of the maximal spasm) which was reversed by naloxone (10^–6 M). Tetrodotoxin (TTX; 10^–6 M) also caused contraction (14% of maximum); morphine completely lost its effect in the presence of TTX. Likewise, the NO synthase inhibitor N^G-nitro-L-arginine (L-NOARG, 10^–4 M) elicited a tonic circular muscle contraction (12% of maximum) and completely prevented the excitatory action of TTX or morphine. The NO donor sodium nitroprusside (10^–7 to 10^–4 M) caused relaxation. In longitudinally oriented preparations in the presence of atropine (10^–6 M), no change in tone was observed upon administration of morphine (10^–6 M), TTX (10^–6 M), or L-NOARG (10^–4 M). In the circular muscle in the absence of atropine, cholecystokinin octapeptide (CCK-8; 10^–9 M) evoked a tonic-phasic contractile response which spontaneously faded away within 3 min. L-NOARG (10^–4 M) failed to affect intensity or duration of the response to CCK-8. It is concluded that NO-releasing myenteric neurons exert a tonic inhibitory influence upon the circular, but not longitudinal muscle of the guinea pig ileum. Morphine and TTX probably contract the circular muscle by reducing the amount of NO released. A release of NO seems to play no role in the contractile effect of CCK-8 or in its spontaneous termination.

The long-term results of 30 patients (31 hips) who underwent derotational femoral varus osteotomy for Legg-Calvé-Perthes disease are presented. Pain, leg-length discrepancy, Trendelenburg sign, and range of motion at the operated hip were examined clinically. Radiographic analysis included measurement of the Wiberg angle, epiphyseal index, acetabular index, and the Mose index. All were found to be satisfactory for patients in the good/fair category. Good/fair results were obtained in 27 (87%) of 31 hips according to Catterall's postoperative classification. Four patients were classified in the poor category due to severe restriction of movement and constant hip pain. Therefore, derotational femoral varus osteotomy is recommended for the treatment of patients with Legg-Calvé-Perthes disease.