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Humeral retroversion and shoulder muscle changes in infants with internal rotation contractures following brachial

Fabian van de Bunt1, Michael L Pearl2, Tom van Essen3

  • 1Department of Orthopedics, Amsterdam UMC, VU University Medical Center, Amsterdam 1081 HV, Netherlands. fabianvdbunt@gmail.com.

World Journal of Orthopedics
|January 2, 2019
PubMed

Insights

Infants with brachial plexus birth palsy (BPBI) and internal rotation contracture show decreased humeral retroversion. This bony change, linked to infraspinatus and subscapularis muscle alterations, requires attention in pediatric treatment.

Area of Science:

  • Pediatric Orthopedics
  • Developmental Anatomy
  • Biomechanical Analysis

Background:

  • Brachial plexus birth palsy (BPBI) can lead to internal rotation contractures in infants.
  • Altered bone morphology, specifically humeral retroversion, is a potential consequence of BPBI and muscle imbalances.

Purpose of the Study:

  • To quantify humeral retroversion in infants diagnosed with BPBI and internal rotation contracture.
  • To investigate the relationship between infraspinatus (IS) and subscapularis (SSc) muscle size and humeral retroversion in affected infants.

Main Methods:

  • Retrospective analysis of 35 infants with BPBI using bilateral MRI scans.
  • Measurement of humeral retroversion using proximal and distal axes.
  • Quantification of IS and SSc muscle cross-sectional areas and correlation with retroversion and passive external rotation.

Main Results:

  • Significantly decreased humeral retroversion was observed on the involved side compared to the uninvolved side (P < 0.01).
  • Reduced cross-sectional areas of both IS and SSc muscles were found in infants with BPBI (P < 0.05).
  • A smaller SSc/IS muscle size ratio was noted on the involved side (P = 0.007).

Conclusions:

  • Decreased humeral retroversion is a common finding in infants with BPBI, even at a young age.
  • Altered humeral retroversion represents a significant structural change that should be considered during the evaluation and treatment of internal rotation contractures in children.
Abstract

Keywords:
Brachial plexusBrachial plexus neuropathiesHumeral retroversionHumerusInfantsShoulder

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