[1] Turku Univ Hosp, Turku, Finland
[2] Univ Turku, Dept Anaesthesia & Intens Care, Turku, Finland
[3] Univ Turku, Dept Paediat Orthopaed Surg, Turku, Finland
[4] Turku Univ Hosp, Dept Anaesthesia & Intens Care, Turku, Finland
[5] Turku Univ Hosp, Dept Paediat Orthopaed Surg, Turku, Finland
[6] Karolinska Inst, Dept Clin Sci Intervent & Technol CLINTEC, Stockholm, Sweden
[7] Karolinska Univ Hosp, Dept Reconstruct Orthopaed, Stockholm, Sweden
[8] Sundsvall & Harnosand Cty Hosp, Dept Orthopaed, Sundsvall, Sweden
[9] Univ Turku, Dept Biostat, Turku, Finland