Recovery potential after postnatal shoulder paralysis

An animal model of neonatal brachial plexus palsy

Hyun-Min Mike Kim, Leesa M. Galatz, Nikunj Patel, Rosalina Das, Stavros Thomopoulos

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Background: Injury to the brachial plexus during birth results in paralysis of the upper extremity in as many as one in 250 births and can lead to substantial functional deficits in the shoulder. The goal of this study was to characterize the development of bone and joint deformities in paralyzed neonatal shoulders and to assess the improvement of these deformities after muscle function recovery with use of an animal model. Methods: Intramuscular injections of botulinum toxin were used to paralyze the supraspinatus, infraspinatus, and posterior deltoid of the left shoulders of mice at birth. Seventy mice were divided into three groups: Botox, recovery, and normal. The twenty-five mice in the Botox group received botulinumtoxin injections until they were killed. The twenty mice in the recovery group received botulinumtoxin injections for different durations and then were allowed injection-free recovery periods until they were killed. The twenty-five mice in the normal group received saline solution injections until they were killed. Radiographs were used to measure shoulder and elbow contractures. Microcomputed tomography was used to examine anatomical parameters of the supraspinatus muscle, humerus, and scapula. Results: The Botox group showed bone and joint deformities including delayed mineralization and flattening of the humeral head, hypoplasia, and introversion (i.e., anteversion) of the humerus, contractures of the shoulder and elbow, hypoplasia of shoulder muscles, hypoplasia of the scapula, and hypoplasia and retroversion of the glenoid. In the recovery group, a significant trend toward normal properties was observed with longer recovery periods (p < 0.05). However, only soft-tissue contractures of the shoulder and elbow were resolved completely with the longest recovery period. Conclusions: This mouse model successfully simulates human neonatal brachial plexus palsy, reproducing most of the bone and joint deformities found in the human condition. The deformities started to develop early in the postnatal period in the paralyzed shoulders and progressed with longer durations of paralysis. Early restoration of muscle function completely resolved the soft-tissue contractures of the shoulder and elbow. However, osseous deformities of the humerus and scapula were never resolved completely. These findings demonstrate the time-dependence of reversibility of musculoskeletal deformities in developing shoulders with neurological deficits. Clinical Relevance: The information in this study provides the basis for further study of the mechanisms and factors influencing upper-extremity musculoskeletal development.

Original languageEnglish (US)
Pages (from-to)879-891
Number of pages13
JournalJournal of Bone and Joint Surgery - Series A
Volume91
Issue number4
DOIs
StatePublished - Apr 1 2009

Fingerprint

Brachial Plexus
Paralysis
Animal Models
Contracture
Elbow
Scapula
Rotator Cuff
Humerus
Muscles
Injections
Joints
Parturition
Upper Extremity
Musculoskeletal Development
Humeral Head
Bone and Bones
X-Ray Microtomography
Botulinum Toxins
Bone Development
Intramuscular Injections

All Science Journal Classification (ASJC) codes

  • Surgery
  • Orthopedics and Sports Medicine

Cite this

Kim, Hyun-Min Mike ; Galatz, Leesa M. ; Patel, Nikunj ; Das, Rosalina ; Thomopoulos, Stavros. / Recovery potential after postnatal shoulder paralysis : An animal model of neonatal brachial plexus palsy. In: Journal of Bone and Joint Surgery - Series A. 2009 ; Vol. 91, No. 4. pp. 879-891.
@article{3093d5b18cc847d8ba8930974748b4f1,
title = "Recovery potential after postnatal shoulder paralysis: An animal model of neonatal brachial plexus palsy",
abstract = "Background: Injury to the brachial plexus during birth results in paralysis of the upper extremity in as many as one in 250 births and can lead to substantial functional deficits in the shoulder. The goal of this study was to characterize the development of bone and joint deformities in paralyzed neonatal shoulders and to assess the improvement of these deformities after muscle function recovery with use of an animal model. Methods: Intramuscular injections of botulinum toxin were used to paralyze the supraspinatus, infraspinatus, and posterior deltoid of the left shoulders of mice at birth. Seventy mice were divided into three groups: Botox, recovery, and normal. The twenty-five mice in the Botox group received botulinumtoxin injections until they were killed. The twenty mice in the recovery group received botulinumtoxin injections for different durations and then were allowed injection-free recovery periods until they were killed. The twenty-five mice in the normal group received saline solution injections until they were killed. Radiographs were used to measure shoulder and elbow contractures. Microcomputed tomography was used to examine anatomical parameters of the supraspinatus muscle, humerus, and scapula. Results: The Botox group showed bone and joint deformities including delayed mineralization and flattening of the humeral head, hypoplasia, and introversion (i.e., anteversion) of the humerus, contractures of the shoulder and elbow, hypoplasia of shoulder muscles, hypoplasia of the scapula, and hypoplasia and retroversion of the glenoid. In the recovery group, a significant trend toward normal properties was observed with longer recovery periods (p < 0.05). However, only soft-tissue contractures of the shoulder and elbow were resolved completely with the longest recovery period. Conclusions: This mouse model successfully simulates human neonatal brachial plexus palsy, reproducing most of the bone and joint deformities found in the human condition. The deformities started to develop early in the postnatal period in the paralyzed shoulders and progressed with longer durations of paralysis. Early restoration of muscle function completely resolved the soft-tissue contractures of the shoulder and elbow. However, osseous deformities of the humerus and scapula were never resolved completely. These findings demonstrate the time-dependence of reversibility of musculoskeletal deformities in developing shoulders with neurological deficits. Clinical Relevance: The information in this study provides the basis for further study of the mechanisms and factors influencing upper-extremity musculoskeletal development.",
author = "Kim, {Hyun-Min Mike} and Galatz, {Leesa M.} and Nikunj Patel and Rosalina Das and Stavros Thomopoulos",
year = "2009",
month = "4",
day = "1",
doi = "10.2106/JBJS.H.00088",
language = "English (US)",
volume = "91",
pages = "879--891",
journal = "Journal of Bone and Joint Surgery - Series A",
issn = "0021-9355",
publisher = "Journal of Bone and Joint Surgery Inc.",
number = "4",

}

Recovery potential after postnatal shoulder paralysis : An animal model of neonatal brachial plexus palsy. / Kim, Hyun-Min Mike; Galatz, Leesa M.; Patel, Nikunj; Das, Rosalina; Thomopoulos, Stavros.

In: Journal of Bone and Joint Surgery - Series A, Vol. 91, No. 4, 01.04.2009, p. 879-891.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Recovery potential after postnatal shoulder paralysis

T2 - An animal model of neonatal brachial plexus palsy

AU - Kim, Hyun-Min Mike

AU - Galatz, Leesa M.

AU - Patel, Nikunj

AU - Das, Rosalina

AU - Thomopoulos, Stavros

PY - 2009/4/1

Y1 - 2009/4/1

N2 - Background: Injury to the brachial plexus during birth results in paralysis of the upper extremity in as many as one in 250 births and can lead to substantial functional deficits in the shoulder. The goal of this study was to characterize the development of bone and joint deformities in paralyzed neonatal shoulders and to assess the improvement of these deformities after muscle function recovery with use of an animal model. Methods: Intramuscular injections of botulinum toxin were used to paralyze the supraspinatus, infraspinatus, and posterior deltoid of the left shoulders of mice at birth. Seventy mice were divided into three groups: Botox, recovery, and normal. The twenty-five mice in the Botox group received botulinumtoxin injections until they were killed. The twenty mice in the recovery group received botulinumtoxin injections for different durations and then were allowed injection-free recovery periods until they were killed. The twenty-five mice in the normal group received saline solution injections until they were killed. Radiographs were used to measure shoulder and elbow contractures. Microcomputed tomography was used to examine anatomical parameters of the supraspinatus muscle, humerus, and scapula. Results: The Botox group showed bone and joint deformities including delayed mineralization and flattening of the humeral head, hypoplasia, and introversion (i.e., anteversion) of the humerus, contractures of the shoulder and elbow, hypoplasia of shoulder muscles, hypoplasia of the scapula, and hypoplasia and retroversion of the glenoid. In the recovery group, a significant trend toward normal properties was observed with longer recovery periods (p < 0.05). However, only soft-tissue contractures of the shoulder and elbow were resolved completely with the longest recovery period. Conclusions: This mouse model successfully simulates human neonatal brachial plexus palsy, reproducing most of the bone and joint deformities found in the human condition. The deformities started to develop early in the postnatal period in the paralyzed shoulders and progressed with longer durations of paralysis. Early restoration of muscle function completely resolved the soft-tissue contractures of the shoulder and elbow. However, osseous deformities of the humerus and scapula were never resolved completely. These findings demonstrate the time-dependence of reversibility of musculoskeletal deformities in developing shoulders with neurological deficits. Clinical Relevance: The information in this study provides the basis for further study of the mechanisms and factors influencing upper-extremity musculoskeletal development.

AB - Background: Injury to the brachial plexus during birth results in paralysis of the upper extremity in as many as one in 250 births and can lead to substantial functional deficits in the shoulder. The goal of this study was to characterize the development of bone and joint deformities in paralyzed neonatal shoulders and to assess the improvement of these deformities after muscle function recovery with use of an animal model. Methods: Intramuscular injections of botulinum toxin were used to paralyze the supraspinatus, infraspinatus, and posterior deltoid of the left shoulders of mice at birth. Seventy mice were divided into three groups: Botox, recovery, and normal. The twenty-five mice in the Botox group received botulinumtoxin injections until they were killed. The twenty mice in the recovery group received botulinumtoxin injections for different durations and then were allowed injection-free recovery periods until they were killed. The twenty-five mice in the normal group received saline solution injections until they were killed. Radiographs were used to measure shoulder and elbow contractures. Microcomputed tomography was used to examine anatomical parameters of the supraspinatus muscle, humerus, and scapula. Results: The Botox group showed bone and joint deformities including delayed mineralization and flattening of the humeral head, hypoplasia, and introversion (i.e., anteversion) of the humerus, contractures of the shoulder and elbow, hypoplasia of shoulder muscles, hypoplasia of the scapula, and hypoplasia and retroversion of the glenoid. In the recovery group, a significant trend toward normal properties was observed with longer recovery periods (p < 0.05). However, only soft-tissue contractures of the shoulder and elbow were resolved completely with the longest recovery period. Conclusions: This mouse model successfully simulates human neonatal brachial plexus palsy, reproducing most of the bone and joint deformities found in the human condition. The deformities started to develop early in the postnatal period in the paralyzed shoulders and progressed with longer durations of paralysis. Early restoration of muscle function completely resolved the soft-tissue contractures of the shoulder and elbow. However, osseous deformities of the humerus and scapula were never resolved completely. These findings demonstrate the time-dependence of reversibility of musculoskeletal deformities in developing shoulders with neurological deficits. Clinical Relevance: The information in this study provides the basis for further study of the mechanisms and factors influencing upper-extremity musculoskeletal development.

UR - http://www.scopus.com/inward/record.url?scp=65349178900&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=65349178900&partnerID=8YFLogxK

U2 - 10.2106/JBJS.H.00088

DO - 10.2106/JBJS.H.00088

M3 - Article

VL - 91

SP - 879

EP - 891

JO - Journal of Bone and Joint Surgery - Series A

JF - Journal of Bone and Joint Surgery - Series A

SN - 0021-9355

IS - 4

ER -