title: Reply to letter concerning "Segmental Pelvic Correlation (SPeC): a novel approach to understanding sagittal plane spinal alignment".
authors.affiliation: Spinal Deformity Unit, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Butler
authors.affiliation: Spinal Deformity Unit, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: Hanny A
authors.initials: HA
authors.lastname: Anwar
authors.affiliation: Spinal Deformity Unit, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Molloy
mesh_terms: D006801:Humans; D008141:Lordosis; D010388:Pelvis; D011859:Radiography; D013131:Spine