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.


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.
Grissom
Leslie E
LE
Department of Medical Imaging, Alfred I. duPont Hospital for Children, Nemours Children's Clinic, P.O. Box 269, Wilmington, DE 19899, USA. lgrissom@nemours.org
Kecskemethy
Heidi H
HH
Bachrach
Steven J
SJ
McKay
Charles
C
Harcke
H Theodore
HT
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D002547:Cerebral Palsy / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D004164:Diphosphonates / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005269:Femur / Q000187:drug effects; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000517:prevention & control; D006132:Growth Plate / Q000187:drug effects; D006801:Humans; D007223:Infant; D007262:Infusions, Intravenous; D008159:Lumbar Vertebrae / Q000187:drug effects; D008297:Male; D010013:Osteogenesis Imperfecta / Q000188:drug therapy*; D010014:Osteolysis / Q000517:prevention & control; D000077268:Pamidronate; D012189:Retrospective Studies
D004164:Diphosphonates; D000077268:Pamidronate