Magnetic resonance imaging findings in relation to the COL9A2 tryptophan allele among patients with sciatica - Karppinen, J; Pääkkö, E; Räinä, S; Tervonen, O; Kurunlahti, M; Nieminen, P; Ala-Kokko, L; Malmivaara, A; Vanharanta, H (Spine, 2002)