Modeling the benefits of pamidronate in children with osteogenesis imperfecta

The influence of ibandronate treatment on bone density and biochemical bone markers in patients with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is characterized by different signs including increased bone fragility, short stature, blue sclera, abnormal tooth growth and often secondary immobility. No curative therapy has been found for this rare disease up to now, and different pharmacological substances have been tried as treatment for severe forms of OI. Promising results were seen with intravenous bisphosphonates in the treatment of patients with OI. The aim of present study was to show the effect of intravenous ibandronate therapy on bone density and bone metabolism markers. We analyzed the data of 27 patients with the diagnosis of OI who were treated off-label with intravenous ibandronate. Ibandronate was administered by intravenous infusion every three months at a dosage of 0.3-2 mg. Bone turnover markers and bone density were measured before starting therapy and every three months during treatment. Bone density was measured by using an ultrasound imaging system providing an accurate image of the calcaneus and by evaluating broadband ultrasound attenuation (BUA). Twenty-seven patients were treated with intravenous ibandronate during the observation period. 18 were female. The mean age of all patients was 23.9 years ± 19.6 (range 4-63). Seventeen patients were categorized to have OI Type I, 5 patients to have OI Type III and 5 patients to have OI Type IV. There was a statistically significant decrease in total alkaline phosphatase (P<0.0001). We detected also a statistically significant decrease in the ratio urinary deoxypyridinoline/urinary creatinine (P=0.0048) and the ratio urinary pyridinoline/urinary creatinine (P<0.0001) respectively. There was also a statistically significant increase in serum magnesium (P=0.034) and BUA (P=0.0071). No statistically significant changes were seen for total serum calcium (P=0.16), the ratio of urine calcium/urine creatinine (P=0.29), alkaline phosphatase (isoform bone) (P=0.3), procollagen-I-peptide (P=0.5), osteocalcin (P=0.9), serum phosphatase (P=0.71), parathormone (P=0.11) and the ratio urine phosphatase/urine creatinine (P=0.58) Therapy with ibandronate in patients with OI leads to a normalisation of bone turnover markers and increasing bone density. Therefore serum alkaline phosphatase and bone density are possible parameters to monitor bisphosphonate treatment in patients with OI.

Conservative versus surgical treatment of osteogenesis imperfecta: a retrospective analysis of 29 patients

The aim of our study was to compare the surgical and conservative treatment of patients affected by fragility fractures and deformities of long bones in osteogenesis imperfecta (OI).Our series consisted of 29 consecutive OI patients treated at our Institute. The series comprised 14 females and 15 males of different ages. The mean age at the time of the first treatment was 8 years (median 6 years; SD ± 15; range 1 to 75). The mean follow-up was 88 months. The Sillence classification was used to classify OI. Fifteen patients were classified as Type I; five as Type III and nine as Type IV.A total number of 245 procedures were recorded. Of these, 147 were surgical (pinning; intramedullary nailing and plating) while 98 were conservative (cast, braces and bandages). Bisphosphonate use was a major variable in the study. Clinical charts and radiographic films were analyzed for complications (delayed union, nonunion, malunion, hardware loosening). We recorded 58 complications: 13 in Type I; 28 in Type III and 17 in Type IV OI. The rate of each complication was: 15/245 nonunions (6.1%), 14/245 delayed unions (5.7%), 14/245 malunions (5.7%) and 15/245 hardware loosenings (6.1%).We found no statistically significant differences between surgical and conservative treatments. Type III OI, which is a very crippling form of the disease, was associated with radiographically poorer results than the other types. In our analysis, the two groups were unbalanced and only five patients were treated with bisphosphonates. Nevertheless, bisphosphonate use can be considered a good adjuvant to both the conservative and surgical treatment of OI in order to reduce the rate of complications.

Is bisphosphonate therapy for benign bone disease associated with impaired dental healing? A case-controlled study

Background

Bisphosphonates are common first line medications used for the management of benign bone disease. One of the most devastating complications associated with bisphosphonate use is osteonecrosis of the jaws which may be related to duration of exposure and hence cumulative dose, dental interventions, medical co-morbidities or in some circumstances with no identifiable aggravating factor. While jaw osteonecrosis is a devastating outcome which is currently difficult to manage, various forms of delayed dental healing may be a less dramatic and, therefore, poorly-recognised complications of bisphosphonate use for the treatment of osteoporosis. It is hypothesised that long-term (more than 1 year's duration) bisphosphonate use for the treatment of post-menopausal osteoporosis or other benign bone disease is associated with impaired dental healing.

Methods/Design

A case-control study has been chosen to test the hypothesis as the outcome event rate is likely to be very low. A total of 54 cases will be recruited into the study following review of all dental files from oral and maxillofacial surgeons and special needs dentists in Victoria where potential cases of delayed dental healing will be identified. Potential cases will be presented to an independent case adjudication panel to determine if they are definitive delayed dental healing cases. Two hundred and fifteen controls (1:4 cases:controls), matched for age and visit window period, will be selected from those who have attended local community based referring dental practices. The primary outcome will be the incidence of delayed dental healing that occurs either spontaneously or following dental treatment such as extractions, implant placement, or denture use.

Discussion

This study is the largest case-controlled study assessing the link between bisphosphonate use and delayed dental healing in Australia. It will provide invaluable data on the potential link between bisphosphonate use and osteonecrosis of the jaws.

Decrease in outpatient department visits and operative interventions due to bisphosphonates in children with osteogenesis imperfecta

INTRODUCTION

Bisphosphonates are currently the medical treatment most often used in children with osteogenesis imperfecta (OI). The purpose of this retrospective pre-post study was to evaluate the efficacy of treatment with bisphosphonates. We measured the effect by evaluating the number of outpatient department consultations and operative interventions before and after treatment with bisphosphonates in children with OI.

METHODS AND MATERIALS

Outpatient department consultation and operative intervention frequencies before and after treatment with bisphosphonates were registered. Children who had at least 2 years of medical records before treatment and at least 2 years after treatment were used in this study.

RESULTS

Of 118 children who were treated with bisphosphonates, 51 (23 boys and 28 girls) fulfilled the inclusion criteria. Statistical analysis revealed a significant decrease in outpatient department consultations (P < 0.000) and operative intervention (P < 0.003) before and after bisphosphonate treatment.

CONCLUSION

The pre-post design of our study shows a significant reduction of the number of outpatient department consultations and operative interventions in patients with OI after treatment with bisphosphonates.

Bisphosphonate treatment in the oim mouse model alters bone modeling during growth

Osteogenesis imperfecta (OI) is a heritable disease, which results from an abnormal amount or structure of Type I collagen. Bisphosphonates, a class of synthetic antiresorptive drugs, used in osteoporosis management, are also used to decrease fracture incidence and improve quality of life in children with OI. In this study, we used the oim mouse to test the hypotheses that pamidronate treatment during active growth (1) produces larger, stronger, stiffer long bone diaphyses without altering bone material properties, and (2) negatively impacts longitudinal bone growth. Our results indicate that femoral cross-sectional moment of inertia in the distal metaphysis tended to increase with pamidronate treatment and that the treated bones are thicker and structurally stiffer, but shorter than their control-dose counterparts.

Short-term efficacy of monthly pamidronate infusion in patients with osteogenesis imperfecta

We evaluated the efficacy of a monthly infusion of pamidronate on the frequency of fractures, biochemical effects, and bone mineral density in children with osteogenesis imperfecta. Eleven patients from 0.9 to 13.8 yr of age were included in this study. The patients were administered pamidronate intravenously (30 mg/m(2)) over a 4-hr period monthly for a period ranging from 6 to 37 months. Height and weight Z-scores did not change significantly. The frequency of fractures was decreased from 2.3+/-1.01 times per year before treatment to 0.6+/-0.69 times per year during treatment. There were no long-term changes in biochemical markers during pamidronate therapy. The mean bone mineral density of the spine and femur increased significantly. Monthly intravenous pamidronate therapy decreased frequencies of fracture and increased bone mineral density without significant adverse events in Korean 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.

Vitamin D intoxication and hypercalcaemia in an infant treated with pamidronate infusions

Bisphosphonates are used for the treatment of childhood hypercalcaemia, especially that due to malignancies. Here we report the use of intravenous pamidronate for the treatment of hypercalcaemia due to vitamin D intoxication in a 3-month-old infant. Serum calcium levels were normalised without complications.

CONCLUSION

pamidronate may be used in hypercalcaemia due to vitamin D intoxication in paediatric cases resistant to hydration, diuretics or corticosteroids.