Cristina R Prall1, Lyna Azzouz2, Christopher Connolly2, Marc Gutierrez2, Natalie Moreno2, Oluyemi Olumolade2, B Kathleen Alsup1, Glenn M Fox3. 1. Division of Anatomical Sciences, Department of Surgery, University of Michigan Medical School, 1137 Catherine St., Ann Arbor, MI, 48109, USA. 2. University of Michigan Medical School, 1137 Catherine St., Ann Arbor, MI, 48109, USA. 3. Division of Anatomical Sciences, Department of Surgery, University of Michigan Medical School, 1137 Catherine St., Ann Arbor, MI, 48109, USA. foxg@med.umich.edu.
Abstract
PURPOSE: With emphasis on the clinical setting, knowledge of anatomical variation decreases misdiagnoses and surgical complications. We report a previously undocumented variant of sternalis muscle and recommend an augmented classification scheme. METHODS: Dissection of the anterior thoracic wall on an 83-year-old female cadaver revealed bilateral sternalis muscles. The Snosek et al. classification system was referenced to describe the variant types. RESULTS: The right sternalis muscle has a single belly and can be classified using the Snosek et al. classification system as a simple type, right single. The left sternalis muscle presented with three muscle bellies, each having a unique pattern of superior attachments (heads). This variation is previously undocumented and requires a more detailed classification. CONCLUSIONS: We propose the addition of a new subtype of sternalis classification, as well as a modification to the Snosek et al. (Clin Anat 27:866-884, 2014) classification scheme, to include classification of different muscle bellies when multiple are present.
PURPOSE: With emphasis on the clinical setting, knowledge of anatomical variation decreases misdiagnoses and surgical complications. We report a previously undocumented variant of sternalis muscle and recommend an augmented classification scheme. METHODS: Dissection of the anterior thoracic wall on an 83-year-old female cadaver revealed bilateral sternalis muscles. The Snosek et al. classification system was referenced to describe the variant types. RESULTS: The right sternalis muscle has a single belly and can be classified using the Snosek et al. classification system as a simple type, right single. The left sternalis muscle presented with three muscle bellies, each having a unique pattern of superior attachments (heads). This variation is previously undocumented and requires a more detailed classification. CONCLUSIONS: We propose the addition of a new subtype of sternalis classification, as well as a modification to the Snosek et al. (Clin Anat 27:866-884, 2014) classification scheme, to include classification of different muscle bellies when multiple are present.