Pamidronate treatment of less severe forms of osteogenesis imperfecta in children

BACKGROUND: Bisphosphonate therapy improves bone quality in children with severe osteogenesis imperfecta (OI). Children with milder phenotypes also have prepubertal fractures, bone pain and reduced bone mass, predisposing them to adult osteoporosis. OBJECTIVE: To evaluate treatment effects of pamidronate in children with mild phenotypes of OI. METHODS: Open label, 2-year observational study of 18 patients, using pamidronate, with clinical, biochemical and radiological monitoring. RESULTS: Over 2 years, bone pain decreased from 16 to 1 patient and disturbed sleep from 12 children to 0. Independent mobility improved from 10 to 17 children. Fracture incidence decreased from 1.6 to 0.5 fractures/child/year. Surgical interventions decreased from a mean 1.3 procedures/patient to 0 in the second year of treatment. Growth velocity remained stable at a mean 4.8 cm/year. Mean lumbar vertebral bone mineral density improved by 40.8%, from 0.375 to 0.528 g/cm2 (p <0.0001), z-score from -3.77 to -2.44 (p <0.0001). Mean vertebral height improved by 17.3%, from 15.6 to 18.38 mm (p = 0.07); plasma alkaline phosphatase decreased from 222 to 169 U/l (p = 0.0009) and urinary deoxypyridinoline crosslinks decreased from 26.7 to 21.8 nmol/mmol creatinine (p = 0.21). Two children with vitamin D insufficiency were concurrently treated. A significant association (r = -0.6, p = 0.008) was shown between age at start of treatment and percentage change in BMD after 2 years. CONCLUSIONS: Pamidronate treatment improves bone quality in children with mild types of OI. It ameliorates clinical symptoms, improves mobility, reduces fracture frequency and thus improves quality of life and in future is likely to reduce the severity and consequences of adult osteoporosis by improved peak bone mass in these children.     

Alendronate treatment in children with osteogenesis imperfecta

BACKGROUND: Recent studies reported beneficial effect of cyclical intravenous administration of pamidronate in children and adolescents with osteogenesis imperfecta (OI). However, this treatment requires frequent hospital admissions and is relatively expensive. Alendronate is an oral bisphosphonate effectively used in adults with osteoporosis. Experience with alendronate treatment in children with OI is limited. AIMS: To report our experience with alendronate in children with OI. METHODS: 12 children with OI (7 with type I, 4 with type III and 1 with type IV; 7 boys, 5 girls) aged 1.8 to 15.4 years (7.9+/-; 4.4 yrs) were included in this retrospective study. The patients were treated with alendronate in a dose of 5-10 mg/day along with calcium (500 mg/day) and vitamin D (400-1000 IU/day) supplements for 19.8+/-11.3 months (range: 7-46 months). Serum calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), osteocalcin (OC), pyrilinks-D and urinary Ca/Cr ratio were studied 3 monthly and bone mineral density (BMD) by DXA on 6-12 monthly basis. RESULTS: Fracture rate of the patients significantly decreased after treatment (1.2+/-1.5 vs. 0.16+/-0.32 per year, P<0.05). Treatment improved bone density in each individual case. Z-scores of lumbar DXA (L2-L4) significantly increased during treatment (-4.60+/-1.30 vs - 2.47+/-1.52, P< 0.05). Urinary pyrilinks-D decreased with treatment (90.8+/-136.3 vs. 35.1+/-29.9, P< 0.05). Serum Ca, P, ALP, OC and urinary Ca/Cr did not change significantly during treatment. CONCLUSION: We conclude that alendronate is effective, safe and practical alternative to intravenous bisphosphonates in treatment of children with OI.     

Bone densitometry in pediatric patients treated with pamidronate

Background: Increasing numbers of children are being treated with the bisphosphonate pamidronate for low bone mineral density, particularly children with increased risk of fractures caused by bone disorders or low/non-weight bearing. Objective: To determine the effect of intravenous pamidronate on the bone mineral density of children with osteogenesis imperfecta and spastic quadriplegic cerebral palsy. Materials and methods: Charts of 38 children with osteogenesis imperfecta (n=20) and spastic quadriplegic cerebral palsy (n=18) treated with pamidronate were retrospectively reviewed. Patients were selected for treatment because of prior fracture and/or abnormally low bone mineral density. All received intravenous pamidronate at two-month to eight-month intervals and were periodically examined using dual energy X-ray absorptiometry. Results: All patients had abnormally low bone mineral density prior to treatment. Lumbar spine bone mineral density and z-scores showed serial improvement in 31 of 32 patients. Spine bone mineral density increased 78±38.1% in OI and 47.4±39.0% in children with cerebral palsy. The area of greatest lateral distal femur bone mineral density improvement was in the metaphysis adjacent to the growth plate, with a 96±87.8% improvement in the osteogenesis imperfecta group and 65.7±55.2% improvement in the cerebral palsy group. Increases in bone mineral density exceeded that expected for age-specific growth. This was demonstrated by improvement in both spine and femur z-scores for both groups. No children with spastic quadriplegic cerebral palsy experienced fractures after the first week of treatment, whereas patients with osteogenesis imperfecta continued to have fractures but at a decreased rate. Conclusions: Intravenous pamidronate given at 3- to 4-month intervals proved to be effective in increasing bone mineral density in patients with osteogenesis imperfecta and spastic quadriplegic cerebral palsy. The greatest gains in bone mineral density were observed in the children with osteogenesis imperfecta, but they did continue to fracture, albeit at a decreased rate. Children with cerebral palsy gained bone mineral density and did not continue to fracture.     

Low-dose intravenous pamidronate treatment in osteogenesis imperfecta

Different therapy models have been tried in order to decrease bone resorption in osteogenesis imperfecta. Bisphosphonates are a group of drugs that mainly suppress osteoclast-mediated bone resorption, thus reducing bone turnover. We assessed the effects of low-dose bisphosphonate treatment in children with osteogenesis imperfecta. Sixteen osteogenesis imperfecta patients (12 female, 4 male) with severe deformities were treated with cyclic (3-4 mg/kg/year) intravenous infusions of bisphosphonate (Aredia-Novartis) therapy for a period ranging from 0.6 to 4.7 years (mean 2.50 +/- 1.09 years). Bone mineral density increased from 0.304 +/- 0.146 g/cm2 to 0.362 +/- 0.142 g/cm2 in the first year and to 0.421 +/- 0.146 g/cm2 in the second year. A clinical response was shown with a reduction in fracture rate and improvement in mobilization scores. Fracture rates decreased from a median of 4/year (0-30/year) before treatment to 0/year (0-5/year) during treatment. Ambulation improved in 10 children and remained unchanged in three. Two of the children were fully functional before therapy and one was below two years of age. No adverse effects were seen with pamidronate infusions of 7-10 mg/kg/year (monthly) or with 4 cycles/year 3-4 mg/kg/year. Low-dose cyclical pamidronate infusions markedly increased bone density and decreased bone fracture rate and should be considered as a part of a multi-disciplinary treatment.     

Osteogenesis imperfecta: anthropometric, skeletal and mineral metabolic effects of long-term intravenous pamidronate therapy

BACKGROUND: Administration of bisphosphonates represents a beneficial therapy in children and adolescents with severe osteogenesis imperfecta (OI) because it significantly reduces the annual rate of bone fractures. AIM: To evaluate the anthropometric, skeletal and mineral metabolic effects of long-term intravenous pamidronate therapy in OI. METHODS: Ten patients, aged 5 mo to 25 y, with OI received cyclical intravenous pamidronate. The yearly dose of pamidronate was approximately 9 mg/kg/d at all ages. Duration of treatment varied from a minimum of 2 y to a maximum of 5 y. Growth, bone mass and mineral metabolic parameters were studied at baseline and repeated every year thereafter. Bone mass was assessed by calculation of bone mineral apparent density (L2-L4 BMAD). This represents the first study on the changes in size-adjusted measures of bone mass observed with such therapy. RESULTS: While on therapy, all children and adolescents grew normally but did not experience any manifest catch-up growth. A significant decrease in the incidence of bone fractures was observed. In seven patients with severe forms, L2-L4 BMAD increased by 80% after the first 2 y of therapy but tended to stabilize or even decrease over the following years despite maintenance of therapy. A significant inverse correlation could be established between urinary Ca excretion and L2-L4 BMAD (r = -0.30, p < 0.05). CONCLUSION: Our results confirm that cyclical pamidronate infusions reduce the incidence of bone fractures and allow normal growth. The improvement in bone mass initially observed after the first 2 y of therapy is not always sustained over the following years despite maintenance of therapy.     

Biochemical bone markers in the assessment and pamidronate treatment of children and adolescents with osteogenesis imperfecta

Aim: To assess the role of biochemical bone markers in classification of children with osteogenesis imperfecta (OI), their possible association with vertebral compression fractures in milder forms of OI and their role in monitoring of intravenous pamidronate (APD) treatment. Methods: Serum total alkaline phosphatase (ALP), bone ALP isoforms (in a subgroup), osteocalcin, type I procollagen carboxy‐terminal propeptide, carboxy‐terminal telopeptide of type I collagen, and urine deoxypyridinoline (DPD) were measured in a cross‐sectional study of 130 untreated individuals, 0.25–20.9 years (median 6.7), with OI types I, III and IV. Of those, sixty‐nine were also assessed longitudinally during monthly APD treatment. Bone mineral density (BMD) was measured by dual‐energy X‐ray absorptiometry. Results: Significant differences in bone markers, however not sufficient for individual clinical use, were found in the larger untreated group but not between subgroups with or without vertebral compressions. All bone markers decreased during treatment for 1.0–12.5 years, but with different relative amounts. Changes were not correlated to the improvement in BMD, mobility or pain. Conclusion: Bone markers are, despite significant differences, not useful for the classification of OI type in the individual child and are not associated with vertebral compressions. Serum ALP and urinary DPD are sensitive in monitoring bisphosphonate treatment.     

Cyclic pamidronate therapy in children with osteogenesis imperfecta: results of treatment and follow-up after discontinuation

BACKGROUND: Cyclic intravenous pamidronate treatment is widely used for symptomatic therapy of osteogenesis imperfecta (OI). However, data after discontinuation are very limited. AIM: The results of cyclical pamidronate treatment in 14 patients with moderate/severe OI and follow up of six of them after discontinuation are presented to assess the effects of pamidronate and its discontinuation. PATIENTS AND METHODS: Pamidronate was administered at a dosage of 0.5 mg/kg for 3 successive days every 2 months in 14 patients with OI aged 5.10 +/- 3.68 years. Treatment was stopped in six patients after a duration of 16.33 +/- 4.63 months, due to stable bone mineral density (BMD) values and/or no fracture in the last 6 months, or due to family demand. The main outcome measures were areal BMD (aBMD) of the lumbar spine, biochemical markers of bone metabolism, fracture rate, and clinical evaluation. RESULTS: Areal BMD and aBMD z-scores showed significant improvement during the treatment period. Both serum and bone-specific alkaline phosphatase values were significantly decreased. Fracture rate reduced significantly from 3.5 +/- 1.01 to 0.83 +/- 0.77 fractures/year. Bone pain, which was severe in five patients, disappeared just after the first cycle, and the activity and mobility of patients increased. aBMD and aBMD z-scores were decreased 1.5 years after discontinuation, although not statistically significant. Annual fracture rate increased significantly. Bone pain recurred in four patients. Pamidronate treatment was reinstituted in five of these patients at the end of 1.5 years. CONCLUSION: Cyclical pamidronate treatment is very effective in children with moderate/severe OI. This treatment should be started early enough before the occurrence of irreversible deformities and must be given for a longer time during the growth period.     

Pamidronate treatment of osteogenesis imperfecta--lack of correlation between clinical severity, age at onset of treatment, predicted collagen mutation and treatment response

Severe forms of osteogenesis imperfecta (OI) are characterised by osteoporosis with multiple fractures, deformity, progressive loss of mobility and chronic bone pain. Bisphosphonates, as osteoclast inhibitors, reduce bone turnover and improve osteoporosis. OBJECTIVE: To investigate the effect of pamidronate treatment of severe OI in children, and find any correlation between clinical severity, age at start of treatment, type of predicted collagen mutation and treatment response. DESIGN: Open, observational trial. PATIENTS: A two-year study of pamidronate treatment was undertaken in a cohort of 18 children, (1.4-14.5 years) with OI types III and IV. INTERVENTIONS: Disodium pamidronate, 1 mg/kg/day for 3 days every 4 months, by i.v. infusion with measurement of bone turnover, bone density, vertebral morphology and skin biopsies to assess collagen mutation. RESULTS: Eleven children have completed 2 years of treatment and three more have completed 20 months. Sustained cessation of bone pain, improved mobility and decreased fracture rate were seen in all patients. Bone turnover decreased slightly but was not statistically significant. Bone mineral density (BMD) of lumbar spine increased by a mean of 124.7 +/- 75.7% over 2 years (Z score mean -5.08 +/- 1.27, to -3.30 +/- 1.71, p <0.001); the greatest change in BMD was seen in the most severely affected patients: 138 +/- 50.6% (severe), 62.47 +/- 22.9% (mild). There was a mean increase in vertebral height at L4 of 68.5% and in vertebral area of 85.4%. The majority of patients had slow electrophoretic migration of type I collagen alpha chains or reduced secretion of type I collagen, indicative of structural, helix-breaking mutations. There was no correlation between phenotypic severity, age at start of treatment and treatment response (r2 = 0.14) CONCLUSIONS: Pamidronate treatment of severe forms of OI is an effective therapeutic modality to increase bone density, decrease fracture rate, increase mobility and improve quality of life, irrespective of the severity of the mutation or clinical phenotype. It has a good short-term safety profile.     

Efficacy of low dose schedule pamidronate infusion in children with osteogenesis imperfecta

BACKGROUND: Osteogenesis imperfecta (OI) is a rare condition in which bones are abnormally brittle with frequent fractures. A variety of therapeutic agents has been used with low efficacy. In this study, we present three patients treated for 4 years with i.v. pamidronate. PATIENTS AND METHODS: Three prepubertal patients, aged 9 (M), 9 (F) and 11 (F) years old, with OI, were treated with 30-60 mg i.v. pamidronate every 6 months over four years. Determinations were made of plasma 1,25-dihydroxycholecalciferol, 25-hydroxycholecalciferol, insulin-like growth factor-I (IGF-I) and its transport protein (IGFBP3), osteocalcin, total alkaline phosphatase and its osseous fraction, and parathormone (PTH) at baseline and after every pamidronate infusion, Densitometry and X-ray of the vertebral column were performed at the same intervals. RESULTS: Significant reductions of number of bone fractures and pain were observed in all patients, despite lack of any modification in biochemical parameters. Lumbar X-ray and densitometry showed a striking improvement by the end of the treatment period. CONCLUSION: Pamidronate seems to be useful in the treatment of patients with osteogenesis imperfecta.     

Intravenous pamidronate treatment of infants with severe osteogenesis imperfecta.

OBJECTIVE: Children with the severe forms of osteogenesis imperfecta have in several studies been treated with intravenous pamidronate, but there are only few reports of the effect of early treatment. AIM: To evaluate the effect of treatment started in infancy. METHODS: In a prospective observational study, with a historic control group, intravenous disodium pamidronate (APD) was given as monthly infusions to 11 children with osteogenesis imperfecta aged 3-13 (median 3.6) months, who had severe osteogenesis imperfecta with congenital bowing of the femora and vertebral compression fractures. RESULTS: During treatment of children aged between 3 and 6 (median 4.5) years, dual-energy x ray absorptiometry measurements of the lumbar spine showed a gradual increase in bone density. Bone metabolism parameters in serum (alkaline phosphatase, osteocalcin, procollagen 1 carboxy-terminal peptide, collagen 1 teleopeptide) and in urine (deoxypyridinoline) indicated a decrease in bone turnover. An improvement of mobility was seen and at the latest recording, at the age of 3.3-6.5 (median 4.8) years, the children could all walk. Vertebral remodelling was seen, with increased vertebral height, and no child developed scoliosis, kyphosis or basilar impression. All children required femoral intramedullar rods for fractures, and five needed tibial rodding for extreme curvatures that prevented functional standing and walking. No adverse effects were seen on growth, fracture healing or blood chemistry. CONCLUSIONS: APD is an efficient symptomatic treatment for infants with severe osteogenesis imperfecta, but additional orthopaedic surgery is often needed. Early treatment may prevent scoliosis and basilar impression. Long-term follow-up is important.     

Two doses of pamidronate in infants with osteogenesis imperfecta.

INTRODUCTION: Current regimens of intravenous pamidronate for infants and children with osteogenesis imperfecta (OI) typically deliver 3-12 mg/kg/year of drug. We wished to ascertain the effect of pamidronate at 6 or 12 mg/kg/year on skeletal health in infants with OI. METHODS: We recruited 12 infants over a period of 4 years. Infants received either 6 or 12 mg/kg/year of pamidronate. Bone outcomes were assessed by skeletal surveys and DXA bone density measurements at baseline and at 12 months. RESULTS: Bone mass increased in both groups. Infants receiving 12 as opposed to 6 mg/kg/year pamidronate had increased spine bone density after adjusting for covariates at study entry (p = 0.04). Crush fractures improved or remained unchanged in all but one infant. Biochemical markers of bone turnover fell but remained within or above the normal range for age. Metaphyseal remodelling was not impaired. CONCLUSIONS: Pamidronate dose in infants may influence lumbar spine bone acquisition. Pamidronate improved vertebral size after prior crush fracturing and did not over-suppress bone turnover.     

Beneficial effect of long term intravenous bisphosphonate treatment of osteogenesis imperfecta.

AIM: To find an effective symptomatic treatment for osteogenesis imperfecta (OI). METHODS: In a prospective observational study disodium pamidronate (APD) was given as monthly intravenous infusions to 28 children and adolescents (aged 0.6-18 years) with severe OI or a milder form of the disease, but with spinal compression fractures. RESULTS: During treatment for 2-9 years, dual energy x ray absorptiometry measurements of the total body and of the lumbar spine showed a gradual increase in bone density. All bone metabolism variables in serum (alkaline phosphatase, osteocalcin, procollagen 1 C-terminal peptide, collagen 1 teleopeptide) and urine (deoxypyridinoline) indicated that there was a decrease in bone turnover. All patients experienced beneficial effects and the younger patients reported a major improvement in wellbeing, pain, and mobility without significant side effects. Vertebral remodelling was also seen. CONCLUSIONS: APD seems to be an efficient symptomatic treatment for children and adolescents with OI.     

Experience with bisphosphonates in osteogenesis imperfecta

Until recently, medical management of osteogenesis imperfecta, a genetic disorder of reduced bone mass and frequent fractures, was elusive, and treatment was focused on maximizing mobility and function. The introduction of bisphosphonates for the treatment of osteogenesis imperfecta 14 years ago changed this paradigm. Cyclic intravenous pamidronate therapy leads to an increase in bone density and a decrease in fracture rate in patients with osteogenesis imperfecta. Pamidronate therapy has a positive impact on functional parameters including improved energy, decreased bone pain, and increased ambulation. Histomorphometric studies have shown that the reduced osteoclast activity results in gains in cortical thickness and trabecular bone volume. Potential negative effects may include prolonged time to heal after osteotomies and a decrease in the rate of bone remodeling. Overall, it seems clear that the benefits of pamidronate therapy outweigh its potential risks in moderate-to-severe osteogenesis imperfecta, and pamidronate therapy has become the standard of care for patients with this condition. Questions remain regarding when treatment should be stopped and the need for pamidronate therapy in patients with mild osteogenesis imperfecta.     

Bone mineral content and collagen defects in osteogenesis imperfecta

Whole-body and spine dual-energy X-ray absorptiometry was done in 63 patients with osteogenesis imperfecta aged 5 to 63 y, and the results were compared with OI types and collagen defects. Bone mineral content (BMC)-for-age, bone area (BA)-for-age, bone mineral density (BMD)-­for-age, and BMC-for-BA were reduced, especially in patients with OI III/IV and/or in those with a qualitative collagen defect. BA-for-height was normal. Some patients with OI I and/or a quantitative collagen defect had BMD at or above -2 z-scores. We conclude (i) that both BMC and BMD differ significantly between OI types and collagen defects, (ii) that reduced BMC-for-age in OI patients is due mainly to reduced height (“short bones”) and reduced BMC-for-BA (“light bones”), whereas BA-for-height (“bone width”) is normal, (iii) that most OI patients have lower than average BMC, but in some mildly affected patients brittleness may exist with only small reductions in BMC.     

Hypercalcaemia in osteogenesis imperfecta treated with pamidronate

Accepted 10 September 1996The response to the bisphophosphonate, pamidronate, is reported in a child with osteogenesis imperfecta who had recurrent symptomatic hypercalcaemia after immobilisation following fractures. Oral clodronate was effective in the prevention of immobilisation hypercalcaemia in the same child. The bisphosphonates may have other roles in osteogenesis imperfecta by decreasing bone turnover.     

Alendronate treatment for infants with osteogenesis imperfecta: demonstration of efficacy in a mouse model

Recent non-placebo-controlled studies of the bisphosphonate pamidronate have shown it to be effective in reducing fractures and improving bone density in infants and children with osteogenesis imperfecta (OI). To evaluate the effects of bisphosphonate treatment in a controlled study, the oim/oim mouse model of OI was studied. Nursing infant mouse pups (approximately 2 wk old) with moderate to severe OI (oim/oim mouse) and age- and background-matched control mice (+/+) were treated either with the third-generation bisphosphonate alendronate (ALN), or with saline. Fracture risk, bone quality, and growth were evaluated over a 12-wk treatment period. ALN at a dose of 0.03 mg/kg/d or saline was administered via s.c. injection to infant oim/oim and wild-type (+/+) mice from 2 to 14 wk of age (n = 20 per subgroup). The average number of fractures sustained by the ALN-treated oim/oim mice was reduced significantly compared with the untreated oim/oim mice (0.7 +/- 0.7 fractures/mouse versus 2.0 +/- 0.2 fractures/mouse). Bone density increased significantly in the femur and the spine with treatment (2.0 +/- 0.5 versus 1.2 +/- 0.5 in femur and 2.1 +/- 0.5 versus1.6 +/- 0.5 in spine). Histologic evaluation revealed the percentage of metaphyseal tibial bone increased significantly with treatment in both +/+ and oim/oim mice. Mechanical testing revealed an increase in structural stiffness for both treated +/+ and oim/oim mice compared with untreated animals. None of the material properties examined were significantly altered with treatment, nor was spinal curvature affected. Weight gain and long bone growth were comparable in the treated and untreated oim/oim mice. In wild-type mice, femur lengths were significantly shorter in the treated mice compared with untreated counterparts. This animal study demonstrates that treatment of OI in mice as early as 2 wk of age with ALN appears to be effective in reducing fractures and increasing bone properties. Based on the data from this study, ALN therapy in infants with OI should prove to be effective.     

Beneficial effect of long term intravenous bisphosphonate treatment of osteogenesis imperfecta

Aim: To find an effective symptomatic treatment for osteogenesis imperfecta (OI). Methods: In a prospective observational study disodium pamidronate (APD) was given as monthly intravenous infusions to 28 children and adolescents (aged 0.6–18 years) with severe OI or a milder form of the disease, but with spinal compression fractures. Results: During treatment for 2–9 years, dual energy x ray absorptiometry measurements of the total body and of the lumbar spine showed a gradual increase in bone density. All bone metabolism variables in serum (alkaline phosphatase, osteocalcin, procollagen 1 C-terminal peptide, collagen 1 teleopeptide) and urine (deoxypyridinoline) indicated that there was a decrease in bone turnover. All patients experienced beneficial effects and the younger patients reported a major improvement in wellbeing, pain, and mobility without significant side effects. Vertebral remodelling was also seen. Conclusions: APD seems to be an efficient symptomatic treatment for children and adolescents with OI.     

Lethal perinatal type II osteogenesis imperfecta in a family with a dominantly inherited type I

The genetic heterogeneity and the difficulty of accurate genetic counseling in some cases of osteogenesis imperfecta (OI) is shown by the present report. All signs characteristic of OI type II were observed in a newborn infant who died immediately after delivery: curved and deformed limbs, multiple bone fractures, enlarged and soft skull. An autosomal recessive mode is usually admitted for OI type II. However, several cases of OI tarda levis (autosomal dominant) are noticed in the maternal family. The possibility of a relationship between these two types of osteogenesis imperfecta in the same family, which might be important for genetic counselling, is discussed.     

Growth of infants with osteogenesis imperfecta treated with bisphosphonate

Background:  Osteogenesis imperfecta (OI) is a heritable bone disease characterized by bone brittleness and various degrees of growth disorder. Cyclic pamidronate therapy is reportedly useful to prevent bone fracture in OI and in infants with OI, but, it remains unclear how infants with OI grow during bisphosphonate therapy.
Methods:  Height and weight measurements of OI infants treated with cyclic pamidronate therapy were taken before and every 6 months during therapy until 18 months. Vertebral morphometry and the concavity index were analyzed using X-ray films taken simultaneously.
Results:  Among OI patients, those in the group for which the height z- score decreased tended to have more femur fractures than those of the group for which the height z- score increased. Morphometry of the lumbar spine showed that compression fractures occurred less during cyclic pamidronate therapy, by which the lumbar bone mineral density increased.
Conclusions:  Bisphosphonate preserved vertebral morphometry during 18 months after starting therapy in infants. Prevention of femur fracture during the infantile period might help prevent short stature; therapeutic strategies during infancy must better emphasize prevention of long bone fracture before the beginning of gait.