[1] Sahlgrens Univ Hosp, Dept Orthopaed, S-41345 Gothenburg, Sweden
[2] Karolinska Inst, Dept Women & Child Hlth, Stockholm, Sweden
[3] Kennedy Krieger Inst, Baltimore, MD USA
[4] Walter Reed Army Med Ctr, Dept Orthopaed, Washington, DC 20307 USA
[5] Johns Hopkins Univ Hosp, Dept Orthopaed, Baltimore, MD 21287 USA
[6] Karolinska Inst, Dept Mol Med & Surg, Stockholm, Sweden