Use of Oral Bisphosphonates in the Treatment of Osteoporosis of Non-walking Children With Cerebral Palsy

Inclusion Criteria: * non-walking children with cerebral palsy * weight \> to or = 20 kg * aged between 10 to 18 years old * with a Z-score (spinal and / or femoral) \<-2 DS * with a good dental status * capable of holding the seated or half seated position for 30 minutes * capable of filling the study questionary * with negative blood pregnancy tests on inclusion for pubescent girls * Using valid contraception means (condoms, oral contraception) for pubescent girls for the whole study duration and 6 months after the end of the study * affiliated to the social security regimen Exclusion Criteria: * history of spine arthrodesis with osteosynthesis * gastro-oesophageal reflux * oesophagal disease or any factor leading to a delaying or slowing the oesophagal transit (such as stenosis or achalasy) * severe difficulties in swallowing * renal failure * history of uveitis * hypersensibility to alendronate or to one of its excipients (microcristalline cellulose, lactose anhydre, croscarmellose sodium, magnesium stearate) * deficiency in calcium or in vitamine D * calcium malabsorption * hereditary galactose intolerance, congenital galactosemia, glucose and galactose malabsorption syndrome * evolutive affection of the upper gastro-intestinal tract such as dysphagia (other than neurological), gastritis, duodenitis, gastro-duodenal ulcers (or with history of ulcers in the previous year), evolutive gastro-intestinal bleeding or history of surgery of the upper gastro-intestinal tract (gastrostomy in particular) * history of necrosis of the maxillar bone or of uncovering of the bone or of cicatrisation delay after a dental surgery * emancipated minor * prior treatment with bisphosphonates * inclusion in another clinical research study