[1] Univ Gothenburg, Sahlgrenska Acad, Sahlgrenska Univ Hosp Ostra, Inst Clin Sci,Dept Orthopaed, SE-41685 Gothenburg, Sweden
[2] Fac Hlth Sci, Dept Biomed & Surg, Div Clin Chem, Bone & Mineral Metab Unit, Linkoping, Sweden
[3] Univ Gothenburg, Sahlgrenska Acad, Queen Silvia Children Hosp, Dept Paediat,Inst Clin Sci, SE-41685 Gothenburg, Sweden