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Abstracts / Bone 48 (2011) S213–S235

patients showed renal function impairment (15% in GF< 60 vs. 7% in GF> 60, p = ns), which was independent of the type of BP treatment and on the presence of associated processes. Age was correlated with serum creat values (r= 0.267, p = 0.007), with the change in creat values (r= 0.24, p = 0.016) and with GF (r = −0.59, p < 0.001). Conclusions: Nearly, 40% of patients with osteoporosis visited in a Rheumatology Department have renal insufficiency, a finding related to the age of the patient. Although a significant decrease in GF was not observed in relation to BP treatment, 10% of patients showed an impairment in renal function, recommending the need to control GF in these patients. This article is part of a Special Issue entitled ECTS 2011. Disclosure of interest: None declared.

doi:10.1016/j.bone.2011.03.523

PP394-S Clinical relevance of serum total 25-hydroxyvitamin D as measured by immunoassay and turboflow LC-MS/MS L. Couchman a, ⁎, R. Musto a, R. Vincent a, R. Clarke a, R. Langworthy a, S. Robinson b, C. Moniz a a Clinical Biochemistry, King's College Hospital, London, UK b ThermoFisher Scientific, Hemel Hempstead, UK Abstract: Hypovitaminosis D is now implicated in impaired bone health and a spectrum of other disorders. Accurate measurement of vitamin D status is important to determine status and supplementation protocols. Currently, analysis of total circulating 25-hydroxyvitamin D (25OHD) in serum is the best indicator of vitamin D status but measurement is not straightforward. A number of immunometric methods exist, which differ in antibody crossreactivity to 25OHD2 and 25OHD3, as well as other related compounds (e.g. 24,25dihydroxyvitamin D) which may be present at significant concentrations in sera. LC-MS/MS methods are today increasingly used, as they can discriminate between 25OHD2 and 25OHD3. We analysed 195 serum samples for total 25OHD from patients undergoing fracture risk assessment, using two chemiluminscent immunoassays (Diasorin Liaison and IDS iSYS) and TurboFlow LC-MS/MS (Chromsystems calibration standards). Analysis of all data (concentration range by LC-MS/MS 1.6–64.9 μg/L) showed correlation between results overall (R 2 value for LC-MS/MS vs Liaison and LC-MS/MS vs iSYS 0.769 and 0.766, respectively). However, paired t-tests (LC-MS/MS vs Liaison, LC-MS/MS vs iSYS and iSYS vs Liaison, respectively) showed significant differences (for all, P < 0.05) between the methods and poor correlation at lower concentrations (<30 μg/L). In particular, at clinically critical concentrations (10–20 μg/L, 75 samples), 32% of patients (Liaison) and 34% of patients (iSYS), would have received different treatment were their samples analysed by this LC-MS/MS method. Apart from cross-reactivity with other endogenous vitamin D metabolites, spurious results were also produced by immunoassay, underlying a need to analyse samples in duplicate, which increases costs. Physicochemical measurement of complex mixtures of vitamin D metabolites by LC-MS/MS seems preferable to immunoreactivity in overcoming some interferences that can affect whether or not to treat. The use of TurboFlow technology, deuterated internal standards and analysis of product ion ratios adds further to the specificity of the LC-MS/MS method. These data do, however, highlight the importance of assay standardisation. This article is part of a Special Issue entitled ECTS 2011. Disclosure of interest: None declared. doi:10.1016/j.bone.2011.03.524

PP395-M Adherence to osteoporosis treatment in real life setting with long follow-up L. Pietrogrande a, ⁎,1, C.E. Zaolino a, G. Radaelli b, E. Raimondo a a UO Ortopedia e Traumatologia AO San Paolo, Milano, Italy b Unit of Medical Statistics, San Paolo Hospital, Università Degli Studi di Milano, Milano, Italy Abstract: Introduction: Differences of the adherence in the treatment of osteoporosis between RCTs and real life have been reported, but few data are available on real life patients with a long follow-up (FU). The aim of this study conducted on an outpatient cohort in Italy is to quantify the adherence to the osteoporosis treatment in real practice setting, to identify the factors that may affect it, and to evaluate the consequence of a sub-optimal adherence. Materials and methods: A consecutive series of 121 women (mean age 65.7 y; SD 8.9; range 44–86) who started treatment for osteoporosis with bisphosphonates after diagnosis of osteoporosis or low bone mass between January 1998 and December 2000 was examined. A total of 590 visits were performed. Mean (SD) FU was 4.1 (4.4) y. Women with FU≥ 3 y (n= 57) were considered to

1

On behalf of GISMO Lombardia.

assess the potential determinants of adherence (mean FU 8.2 y). Adherence was quantified using the Medication Possession Ratio (MPR) per year and the MPR per visit for each patient. Adherence to treatment was defined as having MPR ≥ 85%. Results: The overall therapy drop-out rates at 1, 3, 5 and 10 y of FU were 36.4%, 52.8%, 61.2%, and 72.8%, respectively. In the whole sample mean MPR was 60.6% (41.4%). Among the motivations of therapy drop-out co-morbidities, selfmade decision, and death were the most frequent (no statistical significance). Among women with FU≥ 3 y mean (SD) MPR was 85.2% (12.2%); problems incompliance were reported in 181 visits (37.8%) on 50 patients (87.7%). In 44% of these visits side effects were reported affecting the compliance, with prevalence of GI intolerance (51.3%). The mean MPR per year adherence was associated with age <65 y (p = 0.040), absence of co-morbidities (p = 0.023), positive history of fracture (p 0.044); having the same physician in FU (p 0.025). The mean MPR per visit adherence was associated with weekly bisphosphonates therapy (p= 0.035). Non-adherent patients had higher risk of fracture (adjusted Odds Ratio = 3.4, 95% CI 1.1 to 10.5, p = 0.032). Conclusions: Main determinants of low adherence described in clinical trials and relationship of adherence with fracture risk are confirmed in this real life study, and it emerges the importance of the relationship between physician and patient in improving the adherence. An adherence rate increase is also detected with fractures history (more motivations).

This article is part of a Special Issue entitled ECTS 2011. Disclosure of interest: None declared.

doi:10.1016/j.bone.2011.03.525

PP396-T Treatment with teriparatide of a sub-prosthetic fracture of the femoral shaft after prolonged alendronate therapy L. Pietrogrande ⁎, C.E. Zaolino, E. Raimondo, A. Fossali UO Ortopedia e Traumatologia AO San Paolo, Università Degli Studi di Milano, Milano, Italy

Abstract: Background: Many recent reports describe cases of atypical femoral fractures of the proximal femur without efficient trauma associated with long-term therapy with alendronate, well known for its anti-fracturative action in osteoporotic patients due to an anti-resorptive action. It is not yet clear the dimension of the problem and the pathophysiological bases, nor the way of treatment of these fractures. Case description: We report a case of a 68-year-old woman that after 12 years of therapy with alendronate, for a low energy impact hip fracture treated with total hip arthroplasty (THA), incurred in a transverse fracture of the femoral diaphysis just below the tip of the stem. The minimal energy that caused the fracture and its radiographic appearance suggest that it is similar to low-bone turnover atypical sub-trochanteric femoral fracture. The fracture was correctly treated with plating, but 6 months after surgical treatment there was the rupture of the plate for non-union. The fracture was fixed again with an LCP plate and a strut bone-graft with cerclages in December 2008. In March 2009 there still was pain in the fracture site during weight-bearing and the radiographic appearance showed an atrophic non-united fracture. The bone turnover markers show a very low remodelling rate. A treatment with teriparatide (1–34 PTH) was started and after 18 months the fracture was healed at the clinical and radiographic evaluation. Discussion: Fractures in bones with a severe suppression of the turnover are an emerging challenge to the orthopaedic surgeons, only the association of an anabolic therapy with a correct surgical treatment of these