Long-bone changes after pamidronate discontinuation in children and adolescents with osteogenesis imperfecta

Cyclical intravenous pamidronate is a widely used symptomatic therapy in moderate to severe osteogenesis imperfecta (OI). The effects of treatment discontinuation on long bone development have not been characterized. In this observational study we used peripheral quantitative computed tomography to assess the radius at the distal metaphysis and at the diaphysis in 23 young OI patients (11 female) who had received pamidronate for at least 3 years. Measurements were performed twice, at the time of treatment discontinuation (when the age of the patients ranged from 5.9 to 21.3 years) and at an average of 1.9 years (range 1.5 to 2.4 years) later. At the time of pamidronate discontinuation, all but one of the patients who were below 15 years of age (n=14) had a positive age- and sex-specific z-score for bone mineral content (BMC) at the metaphysis, resulting in a mean z-score of +2.0 (SD=1.0) for this subgroup. In contrast, patients aged 15 years or older (n=9) had an average metaphyseal BMC z-score of -1.5 (SD=1.5). After pamidronate discontinuation, metaphyseal BMC z-score decreased by an average of 2.4 (SD=2.0) in the whole group. The change in BMC z-score was growth-dependent, as BMC z-scores decreased by about 2 or more in all patients in whom distal radius growth plates were open when pamidronate was discontinued. In contrast, none of the 11 patients with closed distal radius growth plates experienced a decrease in metaphyseal BMC z-score by more than 2. At the diaphysis, the average BMC z-score was low at the time of the last pamidronate infusion [z-score -1.7 (SD=1.4)]. After pamidronate discontinuation, the average diaphyseal BMC z-score decreased by only 0.3 (SD=0.4). In summary, this study shows that the effect of pamidronate discontinuation is much larger at the radial metaphysis than at the diaphysis and is dependent on growth. Metaphyseal bone tissue added by longitudinal growth after treatment discontinuation has a lower density than tissue created during treatment. It is possible that this produces zones of localized bone fragility after pamidronate treatment is stopped in growing children.     

Vertebral morphometry in children and adolescents with osteogenesis imperfecta: effect of intravenous pamidronate treatment

Results in small patient series suggest that cyclical intravenous treatment with pamidronate can lead to reshaping of compressed vertebral bodies in children and adolescents with osteogenesis imperfecta (OI), but more detailed analyses are lacking. In this study of patients with moderate to severe OI (age range 0.1 to 16.7 years), we used vertebral morphometry to longitudinally assess changes in lumbar vertebral shape before (n = 17 patients) and during 2 to 4 years of pamidronate treatment (n = 72 patients). Anterior, posterior and midpoint vertebral heights of lumbar vertebrae L1 to L4 were determined on lateral lumbar spine X-rays and were related to vertebral body length in the antero-posterior direction. Before pamidronate treatment, vertebral body height ratios did not change significantly, but the mean concavity index (defined as the ratio between midpoint and posterior vertebral body heights) decreased by 22% (P = 0.002). Pamidronate treatment was associated with an increase in vertebral height ratio at each of the 12 sites that were analyzed. Consequently, patients who had received pamidronate for an average of 3 years had less compressed vertebrae than a historical control group of patients who had the same OI type, age and sex but who had not received pamidronate. Multiple regression analysis revealed that age was negatively and lumbar spine areal bone mineral density z score was positively associated with vertebral shape at baseline. The main determinant of treatment response was the severity of vertebral deformities at baseline. These results suggest that vertebral deformations worsen in patients with moderate to severe OI who do not receive medical treatment and that pamidronate helps to reverse this trend. In moderate to severe forms of OI, pamidronate should be started as early as possible to treat or to prevent vertebral deformations.     

Effect of cyclical intravenous pamidronate therapy in children with osteogenesis imperfecta. Open-label study in seven patients

OBJECTIVES: To evaluate the efficacy of pamidronate in protecting against fractures, increasing bone mineral density (BMD), and decreasing bone remodeling marker levels in children with osteogenesis imperFecta. PATIENTS AND METHODS: Seven children (two girls and five boys; mean age, 8.5 years) were given cyclical intravenous pamidronate (Aredia) for 1 to 7 years, with a mean cycle duration of 6 months and a mean dose of 1.86 mg/kg/cycle. Four patients had type III and three type IV disease according to the Sillence classification scheme. RESULTS: A trend toward a decrease in the fracture rate as compared to the pretreatment period was found, but the difference was not significant in this small sample (P = 0.09). Lumbar spine BMD showed a significant annual increase (+26.7%, P = 0.03) far greater than the expected mean annual increase related to growth. No significant decreases in bone remodeling markers were noted. CONCLUSION: Pamidronate seems useful in the treatment of osteogenesis imperfecta in children, since it increases BMD and reduces the fracture rate, in keeping with the findings from the larger series studied by Glorieux. Pamidronate is a symptomatic, noncurative treatment that does not correct the genetic abnormalities responsible for the histological bone alterations.     

Intravenous pamidronate treatment of children under 36 months of age with osteogenesis imperfecta

INTRODUCTION: Bone mineral density (BMD) and fracture rates in children with osteogenesis imperfecta (OI) have been shown to improve with bisphosphonate therapy. There are limited data available on the efficacy of this therapy in children with OI under the age of 3 years. To examine this, we instituted a prospective clinical trial of intravenous bisphosphonate to study safety, feasibility, and efficacy of this therapy. MATERIALS AND METHODS: Nine infants and young children with osteogenesis imperfecta (age range 1-35 months) were treated with intravenous pamidronate. Six had type II OI, two had type I, and one had type IV. Pamidronate was administered in cycles of 3 consecutive days. The total duration of therapy ranged from 11 to 29 months (mean 17 months). RESULTS: During treatment, the mean annualized percent change in total body areal BMD was 25% (range 11-40%). Pamidronate therapy resulted in sustained and significant decreases in serum calcium and bone-specific alkaline phosphatase and in urine calcium/creatinine and NTX/creatinine. Fracture rate in the group decreased from 80 fractures in 111 months before treatment to 25 fractures in 152 months after treatment (P<0.01). Linear growth and weight gain were maintained. Other than fevers in several infants following the initial dose of intravenous bisphosphonate no adverse effects of therapy were noted. CONCLUSIONS: Our data support that intravenous pamidronate therapy is safe, increases BMD, and reduces fracture rates in very young children with OI. Currently, it would seem to be the best available treatment for these children.     

Respiratory distress with pamidronate treatment in infants with severe osteogenesis imperfecta

This report aims to describe the adverse respiratory events associated with the first pamidronate cycle in four infants with severe osteogenesis imperfecta (OI) who were less than 2 years of age. Fifty-nine infants with severe OI were commenced on cyclical intravenous pamidronate therapy in an observation trial. Routine observations were measured during each infusion cycle. During the first treatment cycle, four infants (7%) with preexisting respiratory compromise developed respiratory distress. The respiratory distress was successfully managed with bronchodilator therapy. Two of the infants required intensive care admission. There was no recurrence of respiratory distress with subsequent pamidronate infusion cycles. In infants with severe OI and preexisting respiratory compromise, the first pamidronate infusion cycle may be associated with an acute deterioration of respiratory function. The etiology is unclear but may involve cytokine release and/or hemodynamic compromise from fluid administration during the first infusion cycle. Close monitoring throughout the first treatment cycle is of paramount importance.     

The effect of cyclical intravenous pamidronate in children and adolescents with osteogenesis imperfecta type V

Intravenous treatment with pamidronate is beneficial in children and adolescents with moderate to severe forms of osteogenesis imperfecta (OI) types I, III and IV, but there is little information on the effects of this treatment on the newly described OI type V. Here, we describe the results of 2 years of pamidronate treatment in 11 children and adolescents with OI type V (age at start of therapy 1.8 to 15.0 years; 6 girls). Pamidronate was given in intravenous cycles at a cumulative yearly dose of 9 mg/kg. The first infusion cycle was associated with fever and mild hypocalcemia in most patients, but no other short-term side effects were noted. Two years of pamidronate treatment led to a decrease in the urinary excretion of N-terminal telopeptide of type I collagen to 50% of baseline levels. Both the size and volumetric bone mineral density of lumbar vertebrae increased compared to age- and sex-matched reference data (P < 0.05 in both cases). Histomorphometry of transiliac bone samples showed an average increase of 86% in cortical thickness (N = 7; P = 0.005). No significant changes with treatment were observed in the age-related z scores of isometric maximal grip force and height. Fracture incidence decreased from 1.5 fractures per year before treatment to 0.5 fractures per year during the fist 2 years of treatment. Ambulation status improved in four patients and remained unchanged in the others. In conclusion, the intravenous pamidronate therapy has a similar effect in OI type V as it has in the other OI types.     

Two-year clinical trial of oral alendronate versus intravenous pamidronate in children with osteogenesis imperfecta.

A 2-year prospective, partially randomized open-label trial comparing oral alendronate with intravenous pamidronate therapy in children with OI showed equivalence in increasing total body BMD, spine BMD, and linear growth, and decreasing bone turnover and fracture incidence. Children with mild OI had greater responses than severe OI in BMD and growth. INTRODUCTION: Bisphosphonate therapies increase BMD and may reduce fractures in children with osteogenesis imperfecta (OI). A study directly comparing oral with intravenous bisphosphonate has not been published. This clinical trial compares oral alendronate with intravenous pamidronate in children with OI using an open-label, prospective, 2-year, randomized design. MATERIALS AND METHODS: Children over the age of 3 years were stratified by bone age, pubertal stage, and type of OI and then randomized to receive oral alendronate 1 mg/kg/day in tablet form or intravenous pamidronate, 3 mg/kg/4 months. One child was assigned to pamidronate. One child randomized to intravenous pamidronate changed to oral alendronate. Eighteen children completed 12 months of therapy: nine on oral alendronate and nine on intravenous pamidronate. Primary outcome efficacy was increase in BMD. Secondary outcomes included changes in bone turnover biomarkers, fracture incidence, and growth. RESULTS: Total body and lumbar spine BMD increased, turnover markers decreased, and linear growth increased equivalently with oral and intravenous therapy. Fracture incidence showed a trend to decrease in both groups, with a significant decrease in fracture rates when the oral and intravenous groups were pooled. There were greater responses in BMD and growth in children with milder OI (type I) than those with more severe disease (types III and IV), but there were no significant effects of age or pubertal stage. CONCLUSIONS: Oral and intravenous bisphosphonate therapies are equally effective in children with OI and are particularly effective in milder forms. The oral route is highly acceptable in children and has practical advantages over the intravenous route.     

Zoledronic acid in children with osteogenesis imperfecta and Bruck syndrome: a 2-year prospective observational study

Summary

Treatment with zoledronic acid (ZA) over 2 years, among 33 children with osteogenesis imperfecta (OI) and five Bruck syndrome cases, showed reduction in fracture rates, pain, and improvement in bone mineral density (BMD) and motor milestones of development. This is the first study reporting the use of bisphosphonates in patients with Bruck syndrome (BS).

Introduction

OI and BS are genetic disorders that result in bone fragility and reduced BMD. There is little literature describing the efficacy and safety of ZA in this population. In this study, we assess the response to treatment with ZA at six monthly intervals in Egyptian children with OI and BS for a period of 2 years.

Methods

Thirty-three patients with OI and five patients with BS were treated with 0.1 mg/kg ZA intravenously every 6 months for 2 years during which they were followed up using different parameters. A clinical severity score (CSS) was applied to the patients before and 2 years after the start of therapy. Comparison of disease severity and response to ZA treatment between autosomal-dominant (AD) and autosomal-recessive (AR) OI patients was also done.

Results

After 6 months of treatment, OI and BS patients showed a significant increase in BMD Z-scores (P?<?0.003 in the spine and P?<?0.004 in the hip), together with a significant drop in fracture rate (P?<?0.001), relief of pain (P?<?0.001), and improvement in ambulation (P?<?0.001). CSS was significantly reduced after 2 years of treatment in both OI and BS patients. AR-OI patients were more severely affected than AD-OI patients and showed more significant improvement.

Conclusion

Zoledronic acid proved to be safe and effective in the treatment of OI and BS. The biannual infusion protocol was convenient to patients. There was a positive correlation between disease severity and benefits of the treatment. The use of the CSS proved to be of value in the assessment of the degree of severity in OI, and with some modifications, it was a valuable tool for the assessment of response to treatment.

     

Treatment of children with osteogenesis imperfecta

Children with moderate to severe forms of osteogenesis imperfecta (OI) require adequate physiotherapy, rehabilitation and orthopedic surgery. Supportive treatment with bisphosphonates can improve the effects of these nonmedicinal treatment modalities. Benefits of bisphosphonate treatment include decreased pain, lower fracture incidence, and better mobility. Among the various bisphosphonates, intravenous pamidronate has been studied in most detail. However, the optimal treatment regimen and the long-term consequences of pamidronate treatment in children are currently unknown. Given these uncertainties, treatment with bisphosphonates during growth should be reserved for patients who have significant clinical problems, such as vertebral compression fractures or long-bone deformities. Medical therapies other than bisphosphonates play a minor role at present. Gene-based therapy currently remains in the realm of preclinical research.     

Surgery versus surgery plus pamidronate in the management of osteogenesis imperfecta patients: a comparative study

The aim of this study was to evaluate the efficacy of pamidronate in the management of osteogenesis imperfecta patients. This study was carried out in two groups. The first was treated only surgically whereas the second was treated by a combined approach, medical and surgical. Forty patients, divided into two groups, were surgically treated in order to correct bony deformities secondary to osteogenesis imperfecta. Group 1: twenty patients were operated at an average age of 6.5 years. Nine were type I, five type III and six type IV. Group 2: this group consisted of 20 patients to whom intermittent intravenous pamidronate were given at regular intervals for an average of 2 years postoperatively. The average age at surgery was 8.5 years. Four patients were type I, six type III, eight type IV, one type V and the remaining one type VII. The results were assessed according to a scoring system suggested and used by the authors since 1999. Group 1: we had three good, nine fair and eight poor results. Group 2: we had 11 excellent, four good and five fair results. The Bone mineral dens (BMD) increased by an average of 35.2% (22.7-112%), and the rate of refracture decreased. Best results in the management of patients can be obtained through the combined approach (surgical and medical treatment). We now advise preoperative and postoperative pamidronate for these patients.     

Intravenous neridronate in children with osteogenesis imperfecta: a randomized controlled study.

In a randomized controlled study, we investigated the effect of treatment with intravenous neridronate in prepubertal children with OI. Our study suggests that quarterly intravenous infusions of the bisphosphonate significantly raise the rate of increase in BMD at both the spine and hip, the projected area of the lumbar vertebrae, and height. These results are associated with a significant decrease in the risk of clinical fractures. INTRODUCTION: Osteogenesis imperfecta (OI) is a heritable disease of connective tissue, characterized by increased bone fragility. Bisphosphonates currently seem to be the most promising therapy, but randomized, controlled studies are scarce and have never been carried out in prepubertal children. MATERIALS AND METHODS: This was a randomized, controlled 3-year clinical trial. The Italian Patients' Society of OI (AsItOI) sent their members affected by any type of OI to two centers at the University of Verona (Italy) to participate in the study. Sixty-four children, 6-11 years of age for boys and 6-9 years of age for girls, with no signs of puberty and who were never treated with bisphosphonates, were randomized to either intravenous neridronate (2 mg/kg infused IV in 30 minutes every 3 months) or no treatment, with a ratio of 2:1. Control patients were given the same bisphosphonate therapy at the end of the first year. BMD and projected bone areas, as measured by DXA, at spine and hip, height, and peripheral fracture incidence, both prospective and retrospective (2 years preceding randomization), were the main outcomes of the study. RESULTS: At the end of the first year, spine and hip BMD rose by 3.5-5.7% in control patients and by 18-25% (p < 0.001 versus controls) in the active group, respectively. During the following 2 years, the treatment in all patients was associated with BMD increases of 10-25% per year. Height and the DXA-derived projected area of lumbar spine rose during the first year of observation significantly more in the active group than in the control group (<0.01 and <0.05, respectively). Both height and spine projected area continued to rise in the treated patients toward levels found in healthy individuals. During the first year of treatment, 45% of the control patients and 27% of the active group had a nonvertebral fracture, but this difference was not statistically significant (p = 0.2). The total number of fractures was 18 in the 22 control patients and 13 in the active group (relative risk, 0.36; 95% CI, 0.15-0.87; p < 0.05). CONCLUSION: Intravenous neridronate infusions, administered quarterly, significantly increase BMD and lower the risk of clinical fracture in prepubertal children with OI.     

Effects of intravenous pamidronate treatment in infants with osteogenesis imperfecta: clinical and histomorphometric outcome.

Clinical and histomorphometric outcome was compared between children with OI who had received pamidronate since infancy and age-matched patients who had never received pamidronate. Pamidronate was associated with improved vertebral shape and mass, higher cortical width, increased cancellous bone volume, and suppressed bone turnover. INTRODUCTION: Observations in small patient series indicate that infants with severe osteogenesis imperfecta (OI) benefit from treatment with cyclical intravenous pamidronate. However, detailed analyses of outcome are lacking for this age group. MATERIALS AND METHODS: Clinical outcome was evaluated in 29 children with OI types I (n = 3), III (n = 14), or IV (n = 12) who started pamidronate therapy before 2 years of age (age at treatment onset: median, 6 months; range, 2 weeks to 23 months) and who had completed 3 years of treatment (total annual pamidronate dose, 9 mg/kg). They were compared with a historical control group of 29 untreated children with severe OI who were matched for OI type and age at the 3-year treatment time-point. In addition, iliac bone histomorphometry was compared between 24 pamidronate-treated patients and 24 age-matched OI patients who had not received pamidronate. RESULTS: Morphometric evaluation of lumbar vertebrae (L(1)-L(4)) showed that the shape of vertebral bodies was better preserved in pamidronate-treated patients. This was accompanied by significantly higher lumbar spine areal and volumetric BMD (+110 and +96%, respectively) and a larger vertebral bone volume (+26%) on densitometry. Regarding mobility function, the Pediatric Evaluation of Disability Inventory gross motor score was 50% greater in the pamidronate group (p < 0.001). Iliac bone histomorphometry showed 61% higher cortical width and 89% higher cancellous bone volume in pamidronate-treated patients. Bone formation rate per bone surface in the pamidronate group was only 17% that of untreated patients. CONCLUSIONS: In conclusion, this study suggests that cyclical pamidronate treatment started in infancy leads to improved bone strength and better gross motor function but also suppresses bone turnover markedly. It is therefore prudent to reserve pamidronate treatment to infant OI patients who present with a moderate to severe phenotype.     

Bone mass, size, and density in children and adolescents with osteogenesis imperfecta: effect of intravenous pamidronate therapy.

Cyclical intravenous therapy with pamidronate improves the clinical course in children and adolescents with osteogenesis imperfecta (OI). In this study, we evaluated the effect of this therapy on lumbar spine bone mass (bone mineral content [BMC]), size (bone volume [BV]), and density (volumetric bone mineral density [vBMD]). Results from 56 patients (age, 0.2-15.9 years; 25 girls) on long-term pamidronate treatment were compared with those of 167 patients who had not received pamidronate before densitometry. In all patients who received pamidronate, BMC, BV, and vBMD increased above levels expected for untreated patients (p < 0.001 in each case). After 4 years of treatment, BMC, BV, and vBMD were 154%, 44%, and 65% higher, respectively, in treated than in untreated patients who were matched for age and OI type. A multiple regression model showed that baseline BMC was negatively associated with the increase in BMC. In conclusion, the bone mass increase in pediatric OI patients receiving pamidronate is caused by increases in both bone size and density. Patients with larger deficits in bone mass at baseline have a more marked bone mass gain during therapy.     

Modern approach to children with osteogenesis imperfecta

Osteogenesis Imperfecta (OI) is characterized by bone fragility. At least seven discrete types have been described ranging from mild disease to a lethal form. In a large number of cases, mutations in one of the two genes encoding type I collagen have been found. In forms recently described (types V, VI, VII), such mutations have been excluded. In two other forms, (Bruck, and osteoporosis - pseudoglioma syndromes) defects in other proteins have been characterized. In OI, bone fragility stems from: decreased bone mass, disturbed organization of bone tissue, and altered bone geometry (size and shape). Histologic studies have shown that increased bone turnover is the rule in OI bone. This justifies using bisphosphonates in order to reduce osteoclast mediated bone resorption. Initial results are encouraging. Cyclical intravenous pamidronate administration reduces bone pain and fracture incidence, and increases bone density and level of ambulation, with minimal side effects. Effects on bone include increase in size of vertebral bodies and thickening of cortical bone. These results allow for more efficacious corrective surgery using intramedullary rodding of the long bones and paravertegral instrumentation. Specific occupational and physiotherapy programs are integral parts of the treatment protocol. This multidisciplinary approach will prevail until strategies aiming at the correction of the basic defect(s) will have come to fruition.     

Limb lengthening in children with osteogenesis imperfecta]

The authors operated on 7 children (5 girls, 2 boys) suffering from osteogenesis imperfecta (oi) type I according to Sillence classification, with lower limbs discrepancy. We elongated 10 segments (7 femurs and 3 tibias). Mean age at operation time was 14.7 years (13-17 years). The mean leg length discrepancy was 9.3 cm (4-18 cm), and shortening of one bone was 6.5 cm (4-9 cm). We used Ilizarov technique twice in tibial lengthening. We used Wagner technique in one tibial elongation and in 7 femur elongation. Except for one tibia, in the remaining cases there was Rush rod inserted intramedullary in the bone being elongated. During tibial elongation we fixed lateral malleous by screw. The osteotomy was performed in proximal metaphysis of the 5 femurs and 3 tibias, and in distal femurs in two cases. The elongation was 1 mm for day, with frequency 4 x 1/4 mm. The mean bone lengthening achieved was 5.5 cm (2-9 cm); the mean lengthening of the limb was 7.9 cm (2-18 cm). The mean time of elongation was 2.8 months (2-5 months). Elongation index was 26 days for 1 cm of lengthening. The mean time of fixator removal was 9.2 months (4-13 months). Healing index was 58 day/1 cm (overall number of days for 1 cm lengthening). The complications occurred in all the patients. Although the risk of numerous complication is high, lower limbs lengthening in children with type I osteogeneis imperfecta is possible to perform and allows equalizing discrepant limbs or, at least reducing the difference.     

Cyclical intravenous pamidronate treatment affects metaphyseal modeling in growing patients with osteogenesis imperfecta.

This analysis of 50 growing patients with osteogenesis imperfecta revealed that 2-4 years of pamidronate treatment lead to abnormalities in the shape of the distal femoral metaphyses. INTRODUCTION: Cyclical intravenous pamidronate therapy is of clinical benefit in children and adolescents with moderate to severe osteogenesis imperfecta (OI) but might interfere with the shaping of long bone metaphyses during growth. MATERIALS AND METHODS: We evaluated the distal femur in 50 growing children with moderate to severe OI (mean age, 6.7 +/- 3.4 years; 26 girls) who had received 2-4 years of pamidronate therapy (annual dose, 9 mg/kg body weight). The mediolateral width of the distal femoral growth plate and of the metaphysis, as well as the ratio between these two measures (called metaphyseal index), were determined on lower limb radiographs. RESULTS: Compared with untreated OI patients who were matched for OI type and age, pamidronate-treated patients had similar growth plate width but wider metaphyses, resulting in a 26% higher metaphyseal index (p < 0.001). Apart from the effect on bone shape, each pamidronate cycle induces a transverse line in metaphyses that are adjacent to active growth plates. Analyses of these transverse lines revealed that they persist for an average time of approximately 4 years, with a range from 2 to 8 years. CONCLUSIONS: Pamidronate interferes with the process of periosteal resorption that is normally responsible for shaping the distal femoral metaphysis. Pamidronate-induced transverse lines disappear with time, supporting the view that these lines represent horizontal trabeculae that undergo remodeling. There is no evidence at present that these treatment induced morphological changes have any clinical implications.     

Intravenous pamidronate therapy in osteogenesis imperfecta: response to treatment and factors influencing outcome

Pamidronate treatment has been shown to improve outcome in osteogenesis imperfecta (OI); however, factors influencing outcome are unclear. The present study was conducted to evaluate the response to pamidronate therapy with special emphasis on factors influencing outcome. Twenty children with OI treated with pamidronate were evaluated in a prospective, open clinical trial. Pamidronate (9 mg x kg(-1) x yr) was administered intravenously at the age of 4.5 +/- 4.2 years for 2.9 +/- 0.7 years (range, 2-3.8 years). Treatment led to increase in bone mineral density (BMD) Z score by 0.7 +/- 0.3 every year resulting in significant improvement in BMD Z score (from -4.6 +/- 1.1 to -2.5 +/- 1.1, P<0.001). BMD Z score was within the reference range (>-2) in 9 subjects (45%) at the last follow-up as against none at initiation of treatment (P<0.001). Fracture rate decreased significantly during treatment (3.3 +/- 1.4 to 0.8 +/- 0.9, P<0.001) with 8 subjects (40%) having no fracture during the treatment period. Significantly greater proportion (88.2%) of children were able to walk at last follow-up compared with those at initiation of treatment (45.4%). Increase in BMD Z score and final BMD Z score was not influenced by age at initiation of treatment, duration of treatment, or initial BMD Z score. Treatment before infancy (n=7) was associated with higher final subjective score (6.3 +/- 0.5 vs 4.9 +/- 1.5, P=0.03). Our study reiterates the efficacy of pamidronate in OI. The poorer response of our subjects may be related to compromised calcium and vitamin D status.     

Efficacy of oral alendronate in children with osteogenesis imperfecta

The purpose of this study was to investigate the efficacy of oral alendronate for children with osteogenesis imperfecta. Nine boys and seven girls of average age 9.5 years were given oral alendronate for an average of 4 years. Fracture frequency decreased, and in more than half of the patients the ambulatory/mobility status improved. Bone mineral density improved significantly, and restoration of collapsed vertebral bodies was observed. Urinary excretion of calcium and a bone resorption marker decreased significantly. Iliac crest physis biopsy showed an expanded primary spongiosa area with numerous multinucleated cells. This study reveals that oral alendronate caused biochemical, radiologic, and histologic changes along with clinical improvement. Oral alendronate treatment, which is convenient for the school-age group, was found to be a tolerable and efficacious treatment for children with moderate or severe osteogenesis imperfecta.     

Effect of alendronate therapy in children with osteogenesis imperfecta

OBJECTIVE: To evaluate the effect of orally administered alendronate in children with osteogenesis imperfecta. METHODS: Thirty children (16 girls and 14 boys; mean age at baseline 10.7 +/- 6.0 years; range 4-16 years) with osteogenesis imperfecta type I (n = 22), III (n = 2), or IV (n = 6) were treated with alendronate (5 mg/day in patients aged 4-10 years and 10 mg/day in children >10 years of age) for 3 years. RESULTS: After 1 year of alendronate therapy we observed a significant increase in areal and volumetric bone mineral density Z-scores (from -2.03 +/- 1.51 to -1.04 +/- 1.20, and from -1.91 +/- 1.38 to -1.33 +/- 1.30, respectively, P < 0.001), together with a significant drop in fracture rate (from 3.77 +/- 1.57 to 0.13 +/- 0.57, P < 0.000001), relief of chronic pain (from 3.83 +/- 1.44 days of pain/week to 0.73 +/- 0.77, P < 0.000001) and improvement in ambulation/mobility (P < 0.00002). After additional 2 years of therapy there were no further significant changes in these parameters, however the improvement was still remarkable in comparison to the pretreatment values (P < 0.003, P < 0.004, P < 0.000001, P < 0.000001 and P < 0.00001, respectively). A significant drop in markers of bone turnover (urinary deoxypyridinoline and serum osteocalcin) occurred after 3 years of therapy (P < 0.003 and 0.004, respectively). No adverse reactions were observed throughout the treatment. CONCLUSIONS: Alendronate has positively influenced quality of life in paediatric patients with osteogenesis imperfecta. Bisphosphonate therapy should be used only in the context of a well-defined protocol.