Examining the Dimensions of the Bicipital Groove: A Human Cadaveric Study

Introduction Understanding the mechanisms and risk factors associated with bicipital groove (BG) morphology is essential for optimizing patient outcomes. Despite interest in the topic of BG morphology, there remains a lack of clarity and consensus on the parameters of BG morphology due to significant methodological limitations in the existing research. The purpose of this study is to explore the dimensions of BG morphology with a methodology rooted in recent research findings to better understand the human anatomy, potentially underpinning various shoulder pathologies.  Methods The right shoulders of seventeen cadavers (nine male and eight female; median age of death: 88.0 years; age of death range: 66.0 - 97.0 years) were included in this cadaveric study. Dissection was done by removing the deltoid musculature and reflecting the long head of the biceps tendon to expose the BG. Measurements for BG morphology included BG width (millimeters, mm), depth (mm), and length (mm). Statistical comparisons were done between male and female measurements using the independent-samples Mann-Whitney U test due to the small sample size.  Results The median width of the BG at the narrowest point was 4.3 mm (mean: 4.7 ± 1.4 mm; range: 3.0 - 7.7 mm) with male cadavers having a significantly wider BG as compared to female cadavers (median: 5.0 mm versus 3.7 mm; p=0.006). The median depth of the BG was 5.1 mm (mean: 5.0 ± 0.7 mm; range: 3.8 - 6.3 mm) with no statistically significant difference between male and female cadavers (median: 4.8 mm versus 5.3 mm; p=0.370). The median length of the BG was 25.1 mm (mean: 25.1 ± 3.3 mm; range: 18.1 - 31.3 mm) with no statistically significant difference between male and female cadavers (median: 25.4 mm versus 23.9 mm; p=0.673). Conclusion The width of the BG at the narrowest point was significantly larger in male cadavers as compared to female cadavers in this study. However, there was no difference between male and female cadavers in terms of depth and length of the BG. This study contributes to the understanding of BG morphology by exploring the dimensions for width, depth, and length of the BG, which may contribute to biceps tendon pathology in clinical practice. Future research should focus on reducing measurement variability and exploring the possible relationship between BG morphology and biceps tendon conditions to further enhance the understanding of this complex relationship.