Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment
ABSTRACT: Background: The incidence of correctional surgery for adult spinal deformity (ASD) has increased significantly over the past 2 decades. Pelvic incidence, an angular measurement, is the gold standard pelvic parameter and is used to classify spinal shapes into Roussouly types. Current liter...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-12-01
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| Series: | North American Spine Society Journal |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666548423000768 |
| _version_ | 1797390368889634816 |
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| author | Justice U. Achonu, MD Kenny Ling, BS Rohit Bhan, MS Alexander Garcia, BS David E. Komatsu, PhD Nicholas A. Pallotta, MD, MS |
| author_facet | Justice U. Achonu, MD Kenny Ling, BS Rohit Bhan, MS Alexander Garcia, BS David E. Komatsu, PhD Nicholas A. Pallotta, MD, MS |
| author_sort | Justice U. Achonu, MD |
| collection | DOAJ |
| description | ABSTRACT: Background: The incidence of correctional surgery for adult spinal deformity (ASD) has increased significantly over the past 2 decades. Pelvic incidence, an angular measurement, is the gold standard pelvic parameter and is used to classify spinal shapes into Roussouly types. Current literature states that restoration of the spine to its original Roussouly classification optimizes outcomes. We propose a new pelvic parameter, pelvic index, as a length measurement to complement pelvic incidence in more accurately characterizing Roussouly types. Methods: This study is a retrospective evaluation of sagittal spinal radiographs of 208 patients who were assessed by a single fellowship trained orthopedic spine surgeon between January and December 2020. Measurements included pelvic incidence, sacroacetabular distance, and L5 vertebral height. Pelvic index was calculated as the ratio of sacroacetabular distance to L5 height. Each spine was also classified into one of the Roussouly types: 1, 2, 3 anteverted pelvis (AP), 3, or 4. The 2 pelvic parameters were compared between groups to assess their ability to differentiate between Roussouly types. Results: Of the 208 patients included, 103 (49.5%) were female and 105 (50.5%) were male. The mean pelvic incidence was 54.9 ± 12.3° and the mean pelvic index was 3.99 ± 0.38. The difference in mean pelvic index was statistically significant between types 1 and 2 (0.15; p=.046) and between types 1 and 3 AP (0.19; p=.029). It was not statistically significant between types 3 and 4 (0.05; p=.251). However, in terms of pelvic incidence, the mean difference was statistically significant only between types 3 and 4 (10.4; p<.001). Conclusions: Pelvic index is the ratio of the sacroacetabular distance to the height of the L5 vertebra. In conjunction with pelvic incidence, pelvic index can help to distinguish between Roussouly types 1 and 2 and between types 1 and 3 AP, the low-pelvic incidence types. |
| first_indexed | 2024-03-08T23:10:43Z |
| format | Article |
| id | doaj.art-b6bcf2dd41384562bb7c2c315fbddf53 |
| institution | Directory Open Access Journal |
| issn | 2666-5484 |
| language | English |
| last_indexed | 2024-03-08T23:10:43Z |
| publishDate | 2023-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | North American Spine Society Journal |
| spelling | doaj.art-b6bcf2dd41384562bb7c2c315fbddf532023-12-15T07:26:28ZengElsevierNorth American Spine Society Journal2666-54842023-12-0116100274Pelvic index: A new pelvic parameter for assessing sagittal spinal alignmentJustice U. Achonu, MD0Kenny Ling, BS1Rohit Bhan, MS2Alexander Garcia, BS3David E. Komatsu, PhD4Nicholas A. Pallotta, MD, MS5Department of Orthopaedics and Rehabilitation, Stony Brook University, HSC-T18, Room 085, Stony Brook, NY 11794-8181, United States; Corresponding author. Department of Orthopaedics and Rehabilitation, Stony Brook University, HSC T-18 – 089, NY 11794, USA. Tel.: (631) 444-7222.Department of Orthopaedics and Rehabilitation, Stony Brook University, HSC-T18, Room 085, Stony Brook, NY 11794-8181, United StatesDepartment of Orthopaedics and Rehabilitation, Stony Brook University, HSC-T18, Room 085, Stony Brook, NY 11794-8181, United StatesDepartment of Orthopaedics and Rehabilitation, Stony Brook University, HSC-T18, Room 085, Stony Brook, NY 11794-8181, United StatesDepartment of Orthopaedics and Rehabilitation, Stony Brook University, HSC-T18, Room 085, Stony Brook, NY 11794-8181, United StatesDepartment of Orthopedic Surgery, Washington University School of Medicine, Campus Box 8233660, South Euclid Avenue, Saint Louis, MO 63110, United StatesABSTRACT: Background: The incidence of correctional surgery for adult spinal deformity (ASD) has increased significantly over the past 2 decades. Pelvic incidence, an angular measurement, is the gold standard pelvic parameter and is used to classify spinal shapes into Roussouly types. Current literature states that restoration of the spine to its original Roussouly classification optimizes outcomes. We propose a new pelvic parameter, pelvic index, as a length measurement to complement pelvic incidence in more accurately characterizing Roussouly types. Methods: This study is a retrospective evaluation of sagittal spinal radiographs of 208 patients who were assessed by a single fellowship trained orthopedic spine surgeon between January and December 2020. Measurements included pelvic incidence, sacroacetabular distance, and L5 vertebral height. Pelvic index was calculated as the ratio of sacroacetabular distance to L5 height. Each spine was also classified into one of the Roussouly types: 1, 2, 3 anteverted pelvis (AP), 3, or 4. The 2 pelvic parameters were compared between groups to assess their ability to differentiate between Roussouly types. Results: Of the 208 patients included, 103 (49.5%) were female and 105 (50.5%) were male. The mean pelvic incidence was 54.9 ± 12.3° and the mean pelvic index was 3.99 ± 0.38. The difference in mean pelvic index was statistically significant between types 1 and 2 (0.15; p=.046) and between types 1 and 3 AP (0.19; p=.029). It was not statistically significant between types 3 and 4 (0.05; p=.251). However, in terms of pelvic incidence, the mean difference was statistically significant only between types 3 and 4 (10.4; p<.001). Conclusions: Pelvic index is the ratio of the sacroacetabular distance to the height of the L5 vertebra. In conjunction with pelvic incidence, pelvic index can help to distinguish between Roussouly types 1 and 2 and between types 1 and 3 AP, the low-pelvic incidence types.http://www.sciencedirect.com/science/article/pii/S2666548423000768Pelvic incidenceAdult spinal deformityRoussoulyPelvic parameterPelvic indexScoliosis |
| spellingShingle | Justice U. Achonu, MD Kenny Ling, BS Rohit Bhan, MS Alexander Garcia, BS David E. Komatsu, PhD Nicholas A. Pallotta, MD, MS Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment North American Spine Society Journal Pelvic incidence Adult spinal deformity Roussouly Pelvic parameter Pelvic index Scoliosis |
| title | Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment |
| title_full | Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment |
| title_fullStr | Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment |
| title_full_unstemmed | Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment |
| title_short | Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment |
| title_sort | pelvic index a new pelvic parameter for assessing sagittal spinal alignment |
| topic | Pelvic incidence Adult spinal deformity Roussouly Pelvic parameter Pelvic index Scoliosis |
| url | http://www.sciencedirect.com/science/article/pii/S2666548423000768 |
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