The Impact of Eccentric Diaphyseal Plate and Screw Placement on the Risk of Peri-Implant Fracture

Joshua D. Namm, Randal P. Morris, Fred L. Speck, Ronald Lindsey

Research output: Contribution to journalArticle

Abstract

CONCLUSIONS: Eccentrically placed plating of humeral shaft fractures significantly increases the risk of peri-implant fracture compared with a centrally placed plate. Directing the proximal-end screw centrally in an eccentrically placed plate may help to mitigate this risk at the proximal end.

CLINICAL RELEVANCE: When possible, care should be taken to place the plate centrally on the bone to avoid increased risk of peri-implant fracture at the proximal plate-bone interface.

METHODS: Twenty osteoporotic fourth-generation composite left humeri were divided into 4 groups and plated with stainless-steel 6-hole locking plates and 4.5-mm screws. Group 1 (control group) consisted of a centrally positioned plate with a centrally placed non-locking end screw at the sixth, most-proximal hole. Group 2 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed through the center of the bone. Group 3 consisted of an eccentrically positioned plate with a locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Group 4 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Each group was tested with a single load to failure in torsion at a rate of 1°/second.

RESULTS: The control group (Group 1) failed at significantly higher peak torque values (51.62 ± 7.35 Nm) than Group 2 (38.98 ± 6.78 Nm; p = 0.006), Group 3 (34.75 ± 1.81 Nm; p < 0.001), and Group 4 (31.55 ± 1.23 Nm; p < 0.001). Failure energy absorbed in Group 1 (2,591.49 ± 819.63 Nm/degree) was significantly higher than Group 3 (1,430.51 ± 449.99 Nm/degree; p = 0.04) and Group 4 (952.49 ± 123.52 Nm/degree; p = 0.004), but not significantly higher than Group 2 (1,847.73 ± 827.35 Nm/degree; p = 0.27).

BACKGROUND: The objective of this study was to determine the impact of the type and orientation of peripheral screw placement in an eccentrically positioned locking plate on the structural integrity of the plate-diaphyseal bone interface. We hypothesized that central placement of the screw at the end of the plate in this setting is more important than screw type (locking versus nonlocking) to limiting the risk of subsequent fracture.

Original languageEnglish (US)
Pages (from-to)1765-1770
Number of pages6
JournalThe Journal of bone and joint surgery. American volume
Volume100
Issue number20
DOIs
StatePublished - Oct 17 2018

Fingerprint

Periprosthetic Fractures
Bone Plates
Humeral Fractures
Bone and Bones
Control Groups
Stainless Steel
Humerus
Torque

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

Cite this

The Impact of Eccentric Diaphyseal Plate and Screw Placement on the Risk of Peri-Implant Fracture. / Namm, Joshua D.; Morris, Randal P.; Speck, Fred L.; Lindsey, Ronald.

In: The Journal of bone and joint surgery. American volume, Vol. 100, No. 20, 17.10.2018, p. 1765-1770.

Research output: Contribution to journalArticle

@article{5aadc6fc216e4c7190216d4b3a83e5ca,
title = "The Impact of Eccentric Diaphyseal Plate and Screw Placement on the Risk of Peri-Implant Fracture",
abstract = "CONCLUSIONS: Eccentrically placed plating of humeral shaft fractures significantly increases the risk of peri-implant fracture compared with a centrally placed plate. Directing the proximal-end screw centrally in an eccentrically placed plate may help to mitigate this risk at the proximal end.CLINICAL RELEVANCE: When possible, care should be taken to place the plate centrally on the bone to avoid increased risk of peri-implant fracture at the proximal plate-bone interface.METHODS: Twenty osteoporotic fourth-generation composite left humeri were divided into 4 groups and plated with stainless-steel 6-hole locking plates and 4.5-mm screws. Group 1 (control group) consisted of a centrally positioned plate with a centrally placed non-locking end screw at the sixth, most-proximal hole. Group 2 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed through the center of the bone. Group 3 consisted of an eccentrically positioned plate with a locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Group 4 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Each group was tested with a single load to failure in torsion at a rate of 1°/second.RESULTS: The control group (Group 1) failed at significantly higher peak torque values (51.62 ± 7.35 Nm) than Group 2 (38.98 ± 6.78 Nm; p = 0.006), Group 3 (34.75 ± 1.81 Nm; p < 0.001), and Group 4 (31.55 ± 1.23 Nm; p < 0.001). Failure energy absorbed in Group 1 (2,591.49 ± 819.63 Nm/degree) was significantly higher than Group 3 (1,430.51 ± 449.99 Nm/degree; p = 0.04) and Group 4 (952.49 ± 123.52 Nm/degree; p = 0.004), but not significantly higher than Group 2 (1,847.73 ± 827.35 Nm/degree; p = 0.27).BACKGROUND: The objective of this study was to determine the impact of the type and orientation of peripheral screw placement in an eccentrically positioned locking plate on the structural integrity of the plate-diaphyseal bone interface. We hypothesized that central placement of the screw at the end of the plate in this setting is more important than screw type (locking versus nonlocking) to limiting the risk of subsequent fracture.",
author = "Namm, {Joshua D.} and Morris, {Randal P.} and Speck, {Fred L.} and Ronald Lindsey",
year = "2018",
month = "10",
day = "17",
doi = "10.2106/JBJS.18.00024",
language = "English (US)",
volume = "100",
pages = "1765--1770",
journal = "Journal of Bone and Joint Surgery - American Volume",
issn = "0021-9355",
publisher = "Journal of Bone and Joint Surgery Inc.",
number = "20",

}

TY - JOUR

T1 - The Impact of Eccentric Diaphyseal Plate and Screw Placement on the Risk of Peri-Implant Fracture

AU - Namm, Joshua D.

AU - Morris, Randal P.

AU - Speck, Fred L.

AU - Lindsey, Ronald

PY - 2018/10/17

Y1 - 2018/10/17

N2 - CONCLUSIONS: Eccentrically placed plating of humeral shaft fractures significantly increases the risk of peri-implant fracture compared with a centrally placed plate. Directing the proximal-end screw centrally in an eccentrically placed plate may help to mitigate this risk at the proximal end.CLINICAL RELEVANCE: When possible, care should be taken to place the plate centrally on the bone to avoid increased risk of peri-implant fracture at the proximal plate-bone interface.METHODS: Twenty osteoporotic fourth-generation composite left humeri were divided into 4 groups and plated with stainless-steel 6-hole locking plates and 4.5-mm screws. Group 1 (control group) consisted of a centrally positioned plate with a centrally placed non-locking end screw at the sixth, most-proximal hole. Group 2 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed through the center of the bone. Group 3 consisted of an eccentrically positioned plate with a locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Group 4 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Each group was tested with a single load to failure in torsion at a rate of 1°/second.RESULTS: The control group (Group 1) failed at significantly higher peak torque values (51.62 ± 7.35 Nm) than Group 2 (38.98 ± 6.78 Nm; p = 0.006), Group 3 (34.75 ± 1.81 Nm; p < 0.001), and Group 4 (31.55 ± 1.23 Nm; p < 0.001). Failure energy absorbed in Group 1 (2,591.49 ± 819.63 Nm/degree) was significantly higher than Group 3 (1,430.51 ± 449.99 Nm/degree; p = 0.04) and Group 4 (952.49 ± 123.52 Nm/degree; p = 0.004), but not significantly higher than Group 2 (1,847.73 ± 827.35 Nm/degree; p = 0.27).BACKGROUND: The objective of this study was to determine the impact of the type and orientation of peripheral screw placement in an eccentrically positioned locking plate on the structural integrity of the plate-diaphyseal bone interface. We hypothesized that central placement of the screw at the end of the plate in this setting is more important than screw type (locking versus nonlocking) to limiting the risk of subsequent fracture.

AB - CONCLUSIONS: Eccentrically placed plating of humeral shaft fractures significantly increases the risk of peri-implant fracture compared with a centrally placed plate. Directing the proximal-end screw centrally in an eccentrically placed plate may help to mitigate this risk at the proximal end.CLINICAL RELEVANCE: When possible, care should be taken to place the plate centrally on the bone to avoid increased risk of peri-implant fracture at the proximal plate-bone interface.METHODS: Twenty osteoporotic fourth-generation composite left humeri were divided into 4 groups and plated with stainless-steel 6-hole locking plates and 4.5-mm screws. Group 1 (control group) consisted of a centrally positioned plate with a centrally placed non-locking end screw at the sixth, most-proximal hole. Group 2 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed through the center of the bone. Group 3 consisted of an eccentrically positioned plate with a locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Group 4 consisted of an eccentrically positioned plate with a non-locking proximal end screw placed perpendicular to the plate and eccentrically across the cortex. Each group was tested with a single load to failure in torsion at a rate of 1°/second.RESULTS: The control group (Group 1) failed at significantly higher peak torque values (51.62 ± 7.35 Nm) than Group 2 (38.98 ± 6.78 Nm; p = 0.006), Group 3 (34.75 ± 1.81 Nm; p < 0.001), and Group 4 (31.55 ± 1.23 Nm; p < 0.001). Failure energy absorbed in Group 1 (2,591.49 ± 819.63 Nm/degree) was significantly higher than Group 3 (1,430.51 ± 449.99 Nm/degree; p = 0.04) and Group 4 (952.49 ± 123.52 Nm/degree; p = 0.004), but not significantly higher than Group 2 (1,847.73 ± 827.35 Nm/degree; p = 0.27).BACKGROUND: The objective of this study was to determine the impact of the type and orientation of peripheral screw placement in an eccentrically positioned locking plate on the structural integrity of the plate-diaphyseal bone interface. We hypothesized that central placement of the screw at the end of the plate in this setting is more important than screw type (locking versus nonlocking) to limiting the risk of subsequent fracture.

UR - http://www.scopus.com/inward/record.url?scp=85055081187&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85055081187&partnerID=8YFLogxK

U2 - 10.2106/JBJS.18.00024

DO - 10.2106/JBJS.18.00024

M3 - Article

C2 - 30334887

AN - SCOPUS:85055081187

VL - 100

SP - 1765

EP - 1770

JO - Journal of Bone and Joint Surgery - American Volume

JF - Journal of Bone and Joint Surgery - American Volume

SN - 0021-9355

IS - 20

ER -