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Footprint mismatch of cervical disc prostheses with Chinese cervical anatomic dimensions.

Dong L, Tan MS, Yan QH, Yi P, Yang F, Tang XS, Hao QY - Chin. Med. J. (2015)

Bottom Line: The average disc sagittal angles (DSAs) of C4-C7 junctions were 5.04°, 5.15°, and 4.13° respectively.Only the Discover brand had a built-in 7° lordotic angle, roughly matching with the DSA.In recent years, possible complications of TDR related with mismatch sizes are increasing, such as subsidence, displacement, and heterotopic ossification.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedics Surgery, China Japan Friendship Hospital, Beijing 100029; Graduate School of Peking Union Medical College, Beijing 100730, China.

ABSTRACT

Background: The footprint of most prostheses is designed according to Caucasian data. Total disc replacement (TDR) has been performed widely for cervical degenerative diseases in China. It is essential to analyze the match sizes of prostheses footprints and Chinese cervical anatomic dimensions in our study.

Methods: The anatomic dimensions of the C4-C7 segments of 138 patients (age range 16-77 years) in a Chinese population were measured by computed tomography scans. We compared the footprints of the most commonly used cervical disc prostheses (Bryan: Medtronic, Minneapolis, MN, USA; Prestige LP: Medtronic, Fridley, Minnesota, USA; Discover: DePuy, Raynham, MA, USA; Prodisc-C: Synthes, West Chester, PA, USA) in China with Chinese cervical anatomic dimensions and assessed the match of their size.

Results: The mismatch of available dimensions of prostheses and anatomic data of cervical endplates ranged from 17.03% (C4/C5, Prestige LP, Prodisc-C) to 57.61% (C6/C7, Discover) in the anterior-posterior (AP) diameter, and 35.51% (C4/C5, Prodisc-C, Prestige LP) to 94.93% (C6/C7, Bryan) in the center mediolateral (CML) diameter. About 21.01% of endplates were larger than the largest prostheses in the AP diameter and 57.25% in the CML diameter. All available footprints of prostheses expect the Bryan with an unfixed height, can accommodate the disc height (DH), however, 36.23% of the middle DH was less than the smallest height of the prostheses. The average disc sagittal angles (DSAs) of C4-C7 junctions were 5.04°, 5.15°, and 4.13° respectively. Only the Discover brand had a built-in 7° lordotic angle, roughly matching with the DSA.

Conclusions: There is a large discrepancy between footprints of prostheses and Chinese cervical anatomic data. In recent years, possible complications of TDR related with mismatch sizes are increasing, such as subsidence, displacement, and heterotopic ossification. Manufacturers of prostheses should introduce or produce additional footprints of prostheses for Chinese TDR.

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Related in: MedlinePlus

The center mediolateral diameter of the superior and inferior vertebral endplates was measured in the coronal computed tomography (CT) scans (a); the anterior-posterior diameter, disc sagittal angle (DSA) and anterior/middle/posterior disc height (A, M, P) were measured in the sagittal CT scans (b).
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Figure 1: The center mediolateral diameter of the superior and inferior vertebral endplates was measured in the coronal computed tomography (CT) scans (a); the anterior-posterior diameter, disc sagittal angle (DSA) and anterior/middle/posterior disc height (A, M, P) were measured in the sagittal CT scans (b).

Mentions: A total of 414 segments at the C4–C7 levels of 138 patients were measured with Picture Archiving and Communication Systems (PACS, Version 11.0, Carestream Health, Toronto, Canada). The following parameters were measured on CT scans [Figure 1]: (1) The anterior-posterior (AP) diameter of the superior and inferior endplates of C4–C7 in the sagittal CT scans. (2) The center mediolateral (CML) diameter of the superior and inferior endplates of C4–C7 in the coronal CT scans. (3) Disc height (DH) includes the height of anterior/middle/posterior disc space. (4) Disc sagittal angle (DSA) between the inferior endplate of the upper vertebra and the superior endplate of the lower vertebra.


Footprint mismatch of cervical disc prostheses with Chinese cervical anatomic dimensions.

Dong L, Tan MS, Yan QH, Yi P, Yang F, Tang XS, Hao QY - Chin. Med. J. (2015)

The center mediolateral diameter of the superior and inferior vertebral endplates was measured in the coronal computed tomography (CT) scans (a); the anterior-posterior diameter, disc sagittal angle (DSA) and anterior/middle/posterior disc height (A, M, P) were measured in the sagittal CT scans (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837838&req=5

Figure 1: The center mediolateral diameter of the superior and inferior vertebral endplates was measured in the coronal computed tomography (CT) scans (a); the anterior-posterior diameter, disc sagittal angle (DSA) and anterior/middle/posterior disc height (A, M, P) were measured in the sagittal CT scans (b).
Mentions: A total of 414 segments at the C4–C7 levels of 138 patients were measured with Picture Archiving and Communication Systems (PACS, Version 11.0, Carestream Health, Toronto, Canada). The following parameters were measured on CT scans [Figure 1]: (1) The anterior-posterior (AP) diameter of the superior and inferior endplates of C4–C7 in the sagittal CT scans. (2) The center mediolateral (CML) diameter of the superior and inferior endplates of C4–C7 in the coronal CT scans. (3) Disc height (DH) includes the height of anterior/middle/posterior disc space. (4) Disc sagittal angle (DSA) between the inferior endplate of the upper vertebra and the superior endplate of the lower vertebra.

Bottom Line: The average disc sagittal angles (DSAs) of C4-C7 junctions were 5.04°, 5.15°, and 4.13° respectively.Only the Discover brand had a built-in 7° lordotic angle, roughly matching with the DSA.In recent years, possible complications of TDR related with mismatch sizes are increasing, such as subsidence, displacement, and heterotopic ossification.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedics Surgery, China Japan Friendship Hospital, Beijing 100029; Graduate School of Peking Union Medical College, Beijing 100730, China.

ABSTRACT

Background: The footprint of most prostheses is designed according to Caucasian data. Total disc replacement (TDR) has been performed widely for cervical degenerative diseases in China. It is essential to analyze the match sizes of prostheses footprints and Chinese cervical anatomic dimensions in our study.

Methods: The anatomic dimensions of the C4-C7 segments of 138 patients (age range 16-77 years) in a Chinese population were measured by computed tomography scans. We compared the footprints of the most commonly used cervical disc prostheses (Bryan: Medtronic, Minneapolis, MN, USA; Prestige LP: Medtronic, Fridley, Minnesota, USA; Discover: DePuy, Raynham, MA, USA; Prodisc-C: Synthes, West Chester, PA, USA) in China with Chinese cervical anatomic dimensions and assessed the match of their size.

Results: The mismatch of available dimensions of prostheses and anatomic data of cervical endplates ranged from 17.03% (C4/C5, Prestige LP, Prodisc-C) to 57.61% (C6/C7, Discover) in the anterior-posterior (AP) diameter, and 35.51% (C4/C5, Prodisc-C, Prestige LP) to 94.93% (C6/C7, Bryan) in the center mediolateral (CML) diameter. About 21.01% of endplates were larger than the largest prostheses in the AP diameter and 57.25% in the CML diameter. All available footprints of prostheses expect the Bryan with an unfixed height, can accommodate the disc height (DH), however, 36.23% of the middle DH was less than the smallest height of the prostheses. The average disc sagittal angles (DSAs) of C4-C7 junctions were 5.04°, 5.15°, and 4.13° respectively. Only the Discover brand had a built-in 7° lordotic angle, roughly matching with the DSA.

Conclusions: There is a large discrepancy between footprints of prostheses and Chinese cervical anatomic data. In recent years, possible complications of TDR related with mismatch sizes are increasing, such as subsidence, displacement, and heterotopic ossification. Manufacturers of prostheses should introduce or produce additional footprints of prostheses for Chinese TDR.

Show MeSH
Related in: MedlinePlus