Difference in Spinal Sagittal Alignment and Health-Related Quality of Life between Males and Females with Cervical Deformity

STUDY DESIGN: Large cohort study. PURPOSE: To clarify spinal sagittal alignment and health-related quality of life (HRQOL) according to sex in volunteers aged >50 years with cervical deformity (CD). OVERVIEW OF LITERATURE: Adult spinal deformities, especially those associated with lumbosacral lesions, are more frequent in females; however, CD is observed to a greater extent in males. METHODS: We divided 656 volunteers (263 males, 393 females; age, 50–89 years [mean, 73 years]) as follows: males with CD (CDM; 82 patients); males without CD (NCDM, 181); females with CD (CDF, 36); and females without CD (NCDF, 357). CD was defined as C2–7 sagittal vertical axis (SVA) ≥40 mm. We measured pelvic tilt (PT), pelvic incidence minus lumbar lordosis (PI−LL), thoracic kyphosis, T1 slope, cervical lordosis, C7 SVA, and C2–7 SVA. HRQOL was evaluated using EuroQOL five dimensions questionnaire (EQ-5D). RESULTS: In CDM, NCDM, CDF, and NCDF groups, the respective parameters were as follows: PT: 15°, 14°, 26°, and 21°; PI−LL: 7°, 5°, 16°, and 10°; C2–7 SVA: 49, 24, 46, and 20 mm; C7 SVA: 61, 40, 75, and 47 mm; and EQ-5D: 0.82, 0.88, 0.78, and 0.81. PT and PI−LL were significantly greater in the CDF group than in the NCDF group (p<0.05) but were not significantly different between CDM and NCDM groups. The CDF group already showed deterioration of spinopelvic alignment, although it was maintained in the CDM group. EQ-5D in showed significantly greater deterioration the CDM group than in the NCDM group; deterioration of lumbopelvic parameters had less influence in males (p<0.05). CONCLUSIONS: Sagittal spinal deformity may have different mechanisms in males and females. The deterioration of spinal sagittal alignment in males may originate from the cervical spine, and CD may be associated with HRQOL.