The effect on the pullout strength by the timing of pedicle screw insertion after calcium phosphate cement injection

Woojin Cho, Chunhui Wu, Serkan Erkan, Matthew M. Kang, Amir A. Mehbod, Ensor E. Transfeldt

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

STUDY DESIGN: Biomechanical Cadaveric Study. OBJECTIVE: To characterize the pullout strength of calcium phosphate cement augmented screws between 0 and 6 minutes after cement injection. SUMMARY OF BACKGROUND DATA: Earlier studies with calcium phosphate cement on pedicle screws inserted into a metal mold or sawbone have shown that the augmentation strength can be affected by the time between cement injection and screw insertion. However, these studies only compared soft cement to completely hardened cement with extended waiting times. These extended waiting times are impractical in live spinal surgeries. METHODS: Twenty-four pedicle screws were inserted and pulled out axially from cadaveric bone to make revision models. The 24 screw holes were randomly divided into 4 groups, with each group having 6 holes. For each group, identical pedicle screws were inserted at 0, 2, 4, and 6 minutes after injection with bioresorbable calcium phosphate cement (CPC). After 24 hours, the augmented screws were pulled out axially and their pullout strengths were compared. RESULTS: The difference between secondary pullout strength and primary pullout strength increased up to 4 minutes after cement injection but decreased after 6 minutes but without statistical difference among the 4 time settings (P>0.3). CONCLUSIONS: The augmented screws had similar fixation strength regardless of the time between cement mixture and screw insertion as long as they are inserted within 6 minutes. Augmentation power tends to increase up to 4 minutes after cement injection but decreases after 6 minutes.

Original languageEnglish (US)
Pages (from-to)116-120
Number of pages5
JournalJournal of Spinal Disorders and Techniques
Volume24
Issue number2
DOIs
StatePublished - Apr 2011
Externally publishedYes

Fingerprint

Injections
Fungi
Metals
calcium phosphate
Pedicle Screws
Bone and Bones

Keywords

  • bioabsorbable
  • calcium phosphate cement
  • cement augmentation
  • pedicle screw
  • pullout strength

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery
  • Orthopedics and Sports Medicine

Cite this

The effect on the pullout strength by the timing of pedicle screw insertion after calcium phosphate cement injection. / Cho, Woojin; Wu, Chunhui; Erkan, Serkan; Kang, Matthew M.; Mehbod, Amir A.; Transfeldt, Ensor E.

In: Journal of Spinal Disorders and Techniques, Vol. 24, No. 2, 04.2011, p. 116-120.

Research output: Contribution to journalArticle

Cho, Woojin ; Wu, Chunhui ; Erkan, Serkan ; Kang, Matthew M. ; Mehbod, Amir A. ; Transfeldt, Ensor E. / The effect on the pullout strength by the timing of pedicle screw insertion after calcium phosphate cement injection. In: Journal of Spinal Disorders and Techniques. 2011 ; Vol. 24, No. 2. pp. 116-120.
@article{d6f8fe7b315147b0b08b7db46326b1ce,
title = "The effect on the pullout strength by the timing of pedicle screw insertion after calcium phosphate cement injection",
abstract = "STUDY DESIGN: Biomechanical Cadaveric Study. OBJECTIVE: To characterize the pullout strength of calcium phosphate cement augmented screws between 0 and 6 minutes after cement injection. SUMMARY OF BACKGROUND DATA: Earlier studies with calcium phosphate cement on pedicle screws inserted into a metal mold or sawbone have shown that the augmentation strength can be affected by the time between cement injection and screw insertion. However, these studies only compared soft cement to completely hardened cement with extended waiting times. These extended waiting times are impractical in live spinal surgeries. METHODS: Twenty-four pedicle screws were inserted and pulled out axially from cadaveric bone to make revision models. The 24 screw holes were randomly divided into 4 groups, with each group having 6 holes. For each group, identical pedicle screws were inserted at 0, 2, 4, and 6 minutes after injection with bioresorbable calcium phosphate cement (CPC). After 24 hours, the augmented screws were pulled out axially and their pullout strengths were compared. RESULTS: The difference between secondary pullout strength and primary pullout strength increased up to 4 minutes after cement injection but decreased after 6 minutes but without statistical difference among the 4 time settings (P>0.3). CONCLUSIONS: The augmented screws had similar fixation strength regardless of the time between cement mixture and screw insertion as long as they are inserted within 6 minutes. Augmentation power tends to increase up to 4 minutes after cement injection but decreases after 6 minutes.",
keywords = "bioabsorbable, calcium phosphate cement, cement augmentation, pedicle screw, pullout strength",
author = "Woojin Cho and Chunhui Wu and Serkan Erkan and Kang, {Matthew M.} and Mehbod, {Amir A.} and Transfeldt, {Ensor E.}",
year = "2011",
month = "4",
doi = "10.1097/BSD.0b013e3181dd7961",
language = "English (US)",
volume = "24",
pages = "116--120",
journal = "Journal of Spinal Disorders",
issn = "1536-0652",
publisher = "Lippincott Williams and Wilkins",
number = "2",

}

TY - JOUR

T1 - The effect on the pullout strength by the timing of pedicle screw insertion after calcium phosphate cement injection

AU - Cho, Woojin

AU - Wu, Chunhui

AU - Erkan, Serkan

AU - Kang, Matthew M.

AU - Mehbod, Amir A.

AU - Transfeldt, Ensor E.

PY - 2011/4

Y1 - 2011/4

N2 - STUDY DESIGN: Biomechanical Cadaveric Study. OBJECTIVE: To characterize the pullout strength of calcium phosphate cement augmented screws between 0 and 6 minutes after cement injection. SUMMARY OF BACKGROUND DATA: Earlier studies with calcium phosphate cement on pedicle screws inserted into a metal mold or sawbone have shown that the augmentation strength can be affected by the time between cement injection and screw insertion. However, these studies only compared soft cement to completely hardened cement with extended waiting times. These extended waiting times are impractical in live spinal surgeries. METHODS: Twenty-four pedicle screws were inserted and pulled out axially from cadaveric bone to make revision models. The 24 screw holes were randomly divided into 4 groups, with each group having 6 holes. For each group, identical pedicle screws were inserted at 0, 2, 4, and 6 minutes after injection with bioresorbable calcium phosphate cement (CPC). After 24 hours, the augmented screws were pulled out axially and their pullout strengths were compared. RESULTS: The difference between secondary pullout strength and primary pullout strength increased up to 4 minutes after cement injection but decreased after 6 minutes but without statistical difference among the 4 time settings (P>0.3). CONCLUSIONS: The augmented screws had similar fixation strength regardless of the time between cement mixture and screw insertion as long as they are inserted within 6 minutes. Augmentation power tends to increase up to 4 minutes after cement injection but decreases after 6 minutes.

AB - STUDY DESIGN: Biomechanical Cadaveric Study. OBJECTIVE: To characterize the pullout strength of calcium phosphate cement augmented screws between 0 and 6 minutes after cement injection. SUMMARY OF BACKGROUND DATA: Earlier studies with calcium phosphate cement on pedicle screws inserted into a metal mold or sawbone have shown that the augmentation strength can be affected by the time between cement injection and screw insertion. However, these studies only compared soft cement to completely hardened cement with extended waiting times. These extended waiting times are impractical in live spinal surgeries. METHODS: Twenty-four pedicle screws were inserted and pulled out axially from cadaveric bone to make revision models. The 24 screw holes were randomly divided into 4 groups, with each group having 6 holes. For each group, identical pedicle screws were inserted at 0, 2, 4, and 6 minutes after injection with bioresorbable calcium phosphate cement (CPC). After 24 hours, the augmented screws were pulled out axially and their pullout strengths were compared. RESULTS: The difference between secondary pullout strength and primary pullout strength increased up to 4 minutes after cement injection but decreased after 6 minutes but without statistical difference among the 4 time settings (P>0.3). CONCLUSIONS: The augmented screws had similar fixation strength regardless of the time between cement mixture and screw insertion as long as they are inserted within 6 minutes. Augmentation power tends to increase up to 4 minutes after cement injection but decreases after 6 minutes.

KW - bioabsorbable

KW - calcium phosphate cement

KW - cement augmentation

KW - pedicle screw

KW - pullout strength

UR - http://www.scopus.com/inward/record.url?scp=79954613322&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79954613322&partnerID=8YFLogxK

U2 - 10.1097/BSD.0b013e3181dd7961

DO - 10.1097/BSD.0b013e3181dd7961

M3 - Article

C2 - 21445025

AN - SCOPUS:79954613322

VL - 24

SP - 116

EP - 120

JO - Journal of Spinal Disorders

JF - Journal of Spinal Disorders

SN - 1536-0652

IS - 2

ER -