TY - JOUR
T1 - Bilateral symmetrical supernumerary heads of biceps brachii with rare pectoralis major insertion
AU - Fraser, Patrick Richard
AU - Howard, Levi William
AU - Rosales, Armando Aviles
AU - Guttmann, Geoffrey David
PY - 2015/1/1
Y1 - 2015/1/1
N2 - During a routine dissection of a 51-year-old Caucasian male cadaver, bilateral symmetrical supernumerary heads (SH) of the biceps brachii muscles with insertion into the pectoralis major (PM) muscles were discovered. Multiple case reports have documented supernumerary heads for the biceps brachii; however, none have shown bilateral insertion into the pectoralis major. This study describes a previously undocumented variation of the SH that has potential for clinical impact. Healthcare providers could be confounded by patients presenting with shoulder pain or muscle tears as a result of the anomaly. Furthermore, MRI studies on patients with possible shoulder muscle tears could reveal unexpected results. Such cases would warrant consideration of SH anomaly and treatment should be adjusted accordingly. The significant bulk and angle of the SH insertion on the PM we observed changes force vectors which would have an unknown effect in performance, surgical interventions and pain syndromes. A second biceps brachii anomaly was observed on the left brachium in addition to the bilateral SH. We postulate that these variants provide the potential for clinical complications regarding muscular injury to these aforementioned muscle groups.
AB - During a routine dissection of a 51-year-old Caucasian male cadaver, bilateral symmetrical supernumerary heads (SH) of the biceps brachii muscles with insertion into the pectoralis major (PM) muscles were discovered. Multiple case reports have documented supernumerary heads for the biceps brachii; however, none have shown bilateral insertion into the pectoralis major. This study describes a previously undocumented variation of the SH that has potential for clinical impact. Healthcare providers could be confounded by patients presenting with shoulder pain or muscle tears as a result of the anomaly. Furthermore, MRI studies on patients with possible shoulder muscle tears could reveal unexpected results. Such cases would warrant consideration of SH anomaly and treatment should be adjusted accordingly. The significant bulk and angle of the SH insertion on the PM we observed changes force vectors which would have an unknown effect in performance, surgical interventions and pain syndromes. A second biceps brachii anomaly was observed on the left brachium in addition to the bilateral SH. We postulate that these variants provide the potential for clinical complications regarding muscular injury to these aforementioned muscle groups.
KW - Biceps brachii
KW - Bilateral
KW - Pectoralis major
KW - Supernumerary head
KW - Variation
UR - http://www.scopus.com/inward/record.url?scp=84939884928&partnerID=8YFLogxK
U2 - 10.1007/s00276-014-1307-5
DO - 10.1007/s00276-014-1307-5
M3 - Article
C2 - 24817560
AN - SCOPUS:84939884928
SN - 0930-1038
VL - 37
SP - 299
EP - 302
JO - Surgical and Radiologic Anatomy
JF - Surgical and Radiologic Anatomy
IS - 3
ER -