A multi-scale modelling approach for analysing landscape service dynamics.

Shifting societal needs drive and shape landscapes and the provision of their services. This paper presents a modelling approach to visualize the regional spatial and temporal dynamics in landscape service supply as a function of changing landscapes and societal demand. This changing demand can result from different policy targets. In this paper we conceptualise the system in which these dynamics take place by explicitly addressing (i) the multifunctional character of a landscape, (ii) the different spatial levels at which interactions between landscape service supply, demand, and land management occur, and (iii) trade-offs in service supply as a result of land management actions. Next, we translate the resulting conceptual framework into an operational model. As a demonstration, this model is applied to simulate changes in landscape service supply driven by regional policies in a rural region of the Netherlands. This application demonstrates potential trade-offs, which emerge in a spatially explicit way in the region over time. It illustrates the potential relevance of modelling landscape service dynamics for environmental management and decision making.

[Surgical treatment of hallux valgus in children and adolescents: 46 cases treated with the Mitchell technique]. / Traitement chirurgical de l'hallux valgus de l'enfant et de l'adolescent. A propos de 46 cas traités par la technique de Mitchell.

PURPOSE OF THE STUDY: The aim of this study is to discuss special features of hallux valgus in children and assess place of a surgical procedure in some patients. MATERIAL AND METHOD: A retrospective study of 40 children (46 feet) operated for hallux valgus was conducted. An etiology was identified in 10 per cent of cases and 90 per cent were considered as idiopathic. From a clinical and radiological analysis of 46 feet, we describe the anatomical particularities and the indications of the surgical treatment. The Mitchell's technique is described in detail. The correction of the metatarsal varus and the metatarsophalangial valgus was obtained without breaking off the growth plate of the first metatarsus. RESULTS: Clinically, results were satisfactory in 84 per cent of the cases. Radiologically, results were excellents in 45 per cent and good in 35 per cent. DISCUSSION AND CONCLUSION: Hallux valgus in the child is often underestimated; operative treatment should be proposed in some patients. Mitchell's technique gives good results with an early and simply correction.

Blount's disease: classification and treatment.

Forty-three tibia vara in 27 patients were analyzed retrospectively in two centers. The criteria for diagnosis of the child form are discussed. A simple classification is suggested to facilitate the choice of treatment. In stage 0 (possible Blount's disease), the patient is younger than 2 1/2 years, and an observation period is indicated for gathering data. In stage 1 (confirmed Blount's disease and absence of medial metaphyseal bony bridge), known as physis+, a valgization osteotomy is proposed. In stage 2 (evidence of a medial metaphysoepiphyseal bony bridge) known as physis-, valgization osteotomy with lateral epiphysiodesis and treatment of the lower limb discrepancy is proposed. For stages 1 and 2, there are two possibilities: normal medial tibial plateau or sloping of the medial tibial plateau, indicating a transphyseal elevation osteotomy. When one-step correction is proposed for stage 2 disorder, external fixators such as Orthofix or Ilizarov devices are useful.

[Percutaneous epiphysiodesis. Analysis of a series of 60 full-grown patients]. / L'épiphysiodèse percutanée. Analyse d'une série de 60 patients à maturité.

PURPOSE OF THE STUDY: Percutaneous epiphysiodesis is the actual treatment for mild leg length discrepancy. The authors discuss complications and efficiency of this technique and its accuracy for the prevision of leg length discrepancy. MATERIAL AND METHOD: We reviewed 60 skeletally mature patients (35 boys, 25 girls). Limb length was defined by clinical and teleradiographic evaluation. Bone age was recorded using Sempé's and Pavia's atlas, using the hand, and Sauvegrain's method, using the elbow. Anticipated discrepancies and timing of epiphysiodesis were calculated using Héchard and Carlioz's graph. The percutaneous curetage was employed in all cases. RESULTS: The treatment was successful for all cases. Complications occurred postoperatively in 2 children who developed an hematoma. 10 children required a surgical revision: 2 cases had an inverted discrepancy, 4 patients were found to have limb deviation, and in four children this treatment was not adequate. The outcome was excellent in 48.3 per cent of cases, satisfactory in 31.7 per cent, acceptable in 6.7 per cent and bad for 13.3 per cent of cases. DISCUSSION: Percutaneous epiphysiodesis is well tolerated in childhood with similar results to other techniques (stapling and Phemister's technique). Our experience suggest that:--complications are rare--this treatment is a satisfactory surgical solution--effective previsions for the best time for surgery have not yet been defined.