The relationship between dual energy X-ray absorptiometry (DXA) and DXA with laser (DXL) measurements in children.

The present study was designed to examine the relationship between bone mineral density (BMD) measurements performed using conventional dual energy X-ray absorptiometry (DXA) in total body (TB), spine, and hip and the more recent technique of DXA with laser (DXL) in the calcaneus in a young population and to explore the diagnostic capacity of the heel DXL. One hundred and twelve persons, 2.2-20.6yr of age, were studied using the 2 techniques. Significant correlations were observed between the heel BMD and BMD values in TB (r=0.73, p<0.001), TB(head excluded(HE)) (r=0.83, p<0.001), spine (r=0.72, p<0.001), and hip (r=0.90, p<0.001). The relationships between DXA and DXL measurements with 95% tolerance intervals are presented. Using heel DXL measurements to predict the lowest DXA quartiles at all the other measured sites revealed sensitivity levels of 0.9 (TB, spine, hip) and 1.0 (TB(HE)) and specificity levels of 0.86 (TB), 0.94 (TB(HE)), 0.92 (spine), and 0.95 (hip). We conclude that BMD values obtained with DXA and DXL correlate well and that the DXA and DXL techniques effectively identify the same individuals with low BMD. The DXL, which is portable, easy to use and gives a low radiation dose, can be useful for assessing bone mass in a young population.

Comprehensive osteoporosis management with easy access to bone mineral density measurements.

BACKGROUND: The majority of people with osteoporosis are never evaluated even though effective treatments are available. The County Council of Värmland in Sweden has implemented an osteoporosis management model that has been shown to be effective in promoting awareness and providing care for osteoporosis patients. Discussions among a prevention group on osteoporosis in the county council were opened in 1997. The county of Värmland covers a large area, and the distances from the peripheral parts to the main city are approximately 300 km and cumbersome for the inhabitants. The importance of having an osteoporosis service that could reach the county inhabitants in a convenient way was therefore recognized. METHODS: Three thousand four hundred patients were evaluated between March 2001 and December 2003. Guidelines for patient selection for bone density testing and treatment guidelines were formulated. Promoting awareness was an important prerequisite for the model to function. This was accomplished by having the measurement devices where the patients showed up and by regular education of the primary care doctors. RESULTS AND CONCLUSIONS: A multidisciplinary team was established and consisted of primary care doctors, orthopaedic surgeons, internists, physiotherapists, a patient organization member, a county health care representative and nurses. Team members met every third month and agreed upon clinical guidelines for implementing the system. The presented osteoporosis management system is not a screening approach as all patients had risk factors for osteoporosis before they were suggested for bone density testing. This study shows that providing a comprehensive package of measures makes it possible to establish an effective osteoporosis management system with limited economical resources.

The effect of anterior cruciate ligament surgery on bone mineral in the calcaneus: a prospective study with a 2-year follow-up evaluation.

PURPOSE: The goal of this study was to evaluate the effect of anterior cruciate ligament (ACL) reconstruction on the bone mineral area mass (BMA) in the calcaneus on the injured and noninjured sides. TYPE OF STUDY: A prospective cohort study with sequential assessments of bone mineral in the calcaneus before and after ACL reconstruction. METHODS: Thirty-four consecutive patients with a unilateral ACL rupture underwent arthroscopic reconstruction using patellar tendon autografts. The BMA was assessed bilaterally in the calcaneus using a gamma camera according to the dual-energy photon absorptiometry technique, before surgery and after 6 and 26 months. RESULTS: Thirty-one of 34 patients (20 men and 11 women) underwent all BMA measurements. The median age at index surgery was 27 (16 to 50) years, and the reconstruction was performed 12 (2 to 192) months after the injury. The median preoperative Tegner activity level increased from 3 (2 to 8) to 7 (2 to 9) at 26 months (P <.0001). The BMA in the calcaneus on both the injured and noninjured side decreased by 16% and 17% respectively from the preoperative measurement to the 26-month control (P =.0014; P =.0006). On all occasions, the BMA was lower on the injured side than on the noninjured side (P =.012). CONCLUSIONS: Patients with a unilateral ACL rupture had a lower BMA in the calcaneus on the injured side compared with the noninjured side. Although patients increased activity levels after reconstruction, the BMA in the calcaneus decreased on both the injured and the noninjured side up to 2 years after surgery. LEVEL OF EVIDENCE: Level II-1, prospective cohort study.

Reference database for dual X-ray and laser Calscan bone densitometer.

The new dual X-ray and laser technology (DXL) gives a more accurate determination of bone mineral density (BMD) than ordinary dual X-ray absorptiometry (DXA) technology because of the ability to eliminate fat tissue both inside and outside the measured bone. In this study the reference database for BMD measured at the calcaneus by the DXL Calscan device is reported. The database was obtained from 993 healthy women and 459 healthy men in a population from southern Sweden. Inclusion criteria were: healthy Swedish Caucasians, 15-85 yr of age for women and 19-85 yr of age for men, no history of osteoporosis treatment, no use of corticosteroids for more than 3 mo, and no extended bed rest. The young adult reference mean BMD for women was found to be 0.483 +/- 0.062 g/cm2 and for men 0.556 +/- 0.074 g/cm2. The age-adjusted odds ratio was 3.7 for a history of fracture among women aged 50 yr and over, comparing subjects with a 1-SD reduction in bone density to subjects with a bone density above this value. The DXL Calscan device used for the study was calibrated weekly against a heel bone phantom. The precision of these measurements was 0.5%. The in vivo precision was 1.2%, as assessed by duplicate measurements on 35 healthy individuals (mean age 52 yr, range 25-72 yr).