### Abstract

Study Design: Retrospective. Objective: To investigate the relationship between the amount of correction achieved (K°) and extent of vertebral column shortening (mm) with posterior vertebral column resection (PVCR). Summary of background data: There is no scientific reference to the correlation between K° and column shortening (mm) with PVCR. Methods: Based on simple geometry, we tested the hypothesis that we could predict the amount of actual kyphosis correction (K°) by calculation on 26 kyphotic PVCR patients. Using multiple linear measurements (mm), two angular approximations (°) were calculated: the geometric approximation (G°) using the geometric calculation (G-cal), and the rough approximation (R°) by more simplistic calculation (Rcal). Both G° and R° were compared against K° as measured on the pre- and postoperative radiographs. If calculated G° and R° is close to measured K°, we can use the calculations (G-cal and R-cal) in the clinical situation. Results: The mean correction of K° was 38°. K°°G° and K°°R° were not significantly greater than 3° and 6°, respectively. As K° was very close to G° and R°,K° can replace G° and R°. Therefore, we can use G-cal and R-cal in the clinical setting and we can determine how much posterior shortening and what cage size is required to obtain a certain amount of K°. Conclusions: With two calculations (G-cal & R-cal), we can determine how much vertebral column shortening (mm) we need during PVCR to obtain the amount of kyphosis correction desired (K°). In order to obtain K°, using the formula deduced from G-cal and R-cal, we can determine the shortening between the upper and lower pedicle screws and cage size.

Original language | English (US) |
---|---|

Pages (from-to) | 65-72 |

Number of pages | 8 |

Journal | Spine Deformity |

Volume | 3 |

Issue number | 1 |

DOIs | |

State | Published - 2015 |

### Fingerprint

### Keywords

- Correlation formula
- Kyphosis correction
- Posterior vertebral column resection
- Vertebral column shortening

### ASJC Scopus subject areas

- Orthopedics and Sports Medicine

### Cite this

*Spine Deformity*,

*3*(1), 65-72. https://doi.org/10.1016/j.jspd.2014.06.006

**Predicting Kyphosis Correction during Posterior-Only Vertebral Column Resection by the Amount of Spinal Column Shortening.** / Cho, Woojin; Lenke, Lawrence G.; Blanke, Kathy M.; O'Shaughnessy, Brian A.; Dorward, Ian G.; Koester, Linda A.; Sides, Brenda A.; Baldus, Christine R.

Research output: Contribution to journal › Article

*Spine Deformity*, vol. 3, no. 1, pp. 65-72. https://doi.org/10.1016/j.jspd.2014.06.006

}

TY - JOUR

T1 - Predicting Kyphosis Correction during Posterior-Only Vertebral Column Resection by the Amount of Spinal Column Shortening

AU - Cho, Woojin

AU - Lenke, Lawrence G.

AU - Blanke, Kathy M.

AU - O'Shaughnessy, Brian A.

AU - Dorward, Ian G.

AU - Koester, Linda A.

AU - Sides, Brenda A.

AU - Baldus, Christine R.

PY - 2015

Y1 - 2015

N2 - Study Design: Retrospective. Objective: To investigate the relationship between the amount of correction achieved (K°) and extent of vertebral column shortening (mm) with posterior vertebral column resection (PVCR). Summary of background data: There is no scientific reference to the correlation between K° and column shortening (mm) with PVCR. Methods: Based on simple geometry, we tested the hypothesis that we could predict the amount of actual kyphosis correction (K°) by calculation on 26 kyphotic PVCR patients. Using multiple linear measurements (mm), two angular approximations (°) were calculated: the geometric approximation (G°) using the geometric calculation (G-cal), and the rough approximation (R°) by more simplistic calculation (Rcal). Both G° and R° were compared against K° as measured on the pre- and postoperative radiographs. If calculated G° and R° is close to measured K°, we can use the calculations (G-cal and R-cal) in the clinical situation. Results: The mean correction of K° was 38°. K°°G° and K°°R° were not significantly greater than 3° and 6°, respectively. As K° was very close to G° and R°,K° can replace G° and R°. Therefore, we can use G-cal and R-cal in the clinical setting and we can determine how much posterior shortening and what cage size is required to obtain a certain amount of K°. Conclusions: With two calculations (G-cal & R-cal), we can determine how much vertebral column shortening (mm) we need during PVCR to obtain the amount of kyphosis correction desired (K°). In order to obtain K°, using the formula deduced from G-cal and R-cal, we can determine the shortening between the upper and lower pedicle screws and cage size.

AB - Study Design: Retrospective. Objective: To investigate the relationship between the amount of correction achieved (K°) and extent of vertebral column shortening (mm) with posterior vertebral column resection (PVCR). Summary of background data: There is no scientific reference to the correlation between K° and column shortening (mm) with PVCR. Methods: Based on simple geometry, we tested the hypothesis that we could predict the amount of actual kyphosis correction (K°) by calculation on 26 kyphotic PVCR patients. Using multiple linear measurements (mm), two angular approximations (°) were calculated: the geometric approximation (G°) using the geometric calculation (G-cal), and the rough approximation (R°) by more simplistic calculation (Rcal). Both G° and R° were compared against K° as measured on the pre- and postoperative radiographs. If calculated G° and R° is close to measured K°, we can use the calculations (G-cal and R-cal) in the clinical situation. Results: The mean correction of K° was 38°. K°°G° and K°°R° were not significantly greater than 3° and 6°, respectively. As K° was very close to G° and R°,K° can replace G° and R°. Therefore, we can use G-cal and R-cal in the clinical setting and we can determine how much posterior shortening and what cage size is required to obtain a certain amount of K°. Conclusions: With two calculations (G-cal & R-cal), we can determine how much vertebral column shortening (mm) we need during PVCR to obtain the amount of kyphosis correction desired (K°). In order to obtain K°, using the formula deduced from G-cal and R-cal, we can determine the shortening between the upper and lower pedicle screws and cage size.

KW - Correlation formula

KW - Kyphosis correction

KW - Posterior vertebral column resection

KW - Vertebral column shortening

UR - http://www.scopus.com/inward/record.url?scp=84927700824&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84927700824&partnerID=8YFLogxK

U2 - 10.1016/j.jspd.2014.06.006

DO - 10.1016/j.jspd.2014.06.006

M3 - Article

VL - 3

SP - 65

EP - 72

JO - Spine Deformity

JF - Spine Deformity

SN - 2212-134X

IS - 1

ER -