William H Cook1, Joseph F Baker2,3. 1. Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Grafton, Auckland 1023, New Zealand williamhcook@gmail.com. 2. Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Grafton, Auckland 1023, New Zealand. 3. Department of Orthopaedic Surgery, Waikato Hospital, Hamilton 3204, New Zealand.
Abstract
BACKGROUND: Most existing studies of lumbar anatomy do not consider ethnic influence and recruit mostly white participants. Recent studies have considered other populations; however, none have assessed Māori, the indigenous people of New Zealand (NZ). A computed tomography study of vertebral body (VB) and canal dimensions was performed for lumbar vertebrae of Māori and NZ European patients to evaluate for ethnic variation. METHODS: Lumbar vertebrae from 196 patients were measured using computed tomography. After interrater and intrarater reliability analyses, a single trained examiner measured VB heights, VB lengths, segmental angle, pedicle height and width, and vertebral canal length (VCL) and vertebral canal width for each level. Canal:body ratio was calculated. Demographic data recorded included age, sex, and ethnicity. RESULTS: VCL remained relatively constant through the lumbar spine; canal width increased to a maximum of 28.2 mm at L5. Canal:body ratios and pedicle height decreased while pedicle width increased to a maximum of 16.1 mm at L5. There were few differences between Māori and NZ Europeans except at the L5 level, where VCL and canal:body ratio were larger in NZ Europeans (P < 0.05), and pedicle height, width, and VB pediculolaminar length were larger in Māori (P < 0.05). Females had generally smaller measurements and age was a positive predictor of measured values (P < 0.05). CONCLUSIONS: This study is the first to characterize lumbar anatomy in a Māori cohort. Adequately powered results demonstrated few differences between Māori and NZ Europeans. Isolated differences observed at L5 may be due to sacropelvic differences, which represent an area for further investigation. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Diagnosis, surgical planning, ethnic differences. This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery.
BACKGROUND: Most existing studies of lumbar anatomy do not consider ethnic influence and recruit mostly white participants. Recent studies have considered other populations; however, none have assessed Māori, the indigenous people of New Zealand (NZ). A computed tomography study of vertebral body (VB) and canal dimensions was performed for lumbar vertebrae of Māori and NZ European patients to evaluate for ethnic variation. METHODS: Lumbar vertebrae from 196 patients were measured using computed tomography. After interrater and intrarater reliability analyses, a single trained examiner measured VB heights, VB lengths, segmental angle, pedicle height and width, and vertebral canal length (VCL) and vertebral canal width for each level. Canal:body ratio was calculated. Demographic data recorded included age, sex, and ethnicity. RESULTS: VCL remained relatively constant through the lumbar spine; canal width increased to a maximum of 28.2 mm at L5. Canal:body ratios and pedicle height decreased while pedicle width increased to a maximum of 16.1 mm at L5. There were few differences between Māori and NZ Europeans except at the L5 level, where VCL and canal:body ratio were larger in NZ Europeans (P < 0.05), and pedicle height, width, and VB pediculolaminar length were larger in Māori (P < 0.05). Females had generally smaller measurements and age was a positive predictor of measured values (P < 0.05). CONCLUSIONS: This study is the first to characterize lumbar anatomy in a Māori cohort. Adequately powered results demonstrated few differences between Māori and NZ Europeans. Isolated differences observed at L5 may be due to sacropelvic differences, which represent an area for further investigation. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Diagnosis, surgical planning, ethnic differences. This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery.
Authors: M R Zindrick; L L Wiltse; E H Widell; J C Thomas; W R Holland; B T Field; C W Spencer Journal: Clin Orthop Relat Res Date: 1986-02 Impact factor: 4.176