Insertional anatomy of the triceps brachii tendon

Hypothesis: Triceps tendon anatomy is important for surgical approaches to the elbow and tendon repair. The purpose of this study is to describe both the qualitative and quantitative anatomy of the triceps brachii tendon insertion. Materials and methods: Thirty-six elbows were dissected from twenty-three cadavers. Dimensions of the triceps tendon proper, lateral triceps expansion, and tendon insertion were measured. The central triceps tendon morphology was described. Results: All specimens showed a distinct lateral tendon expansion continuous with the anconeus fascia (mean width, 16.8 mm). The mean width of the proper triceps tendon was 23.7 mm. The mean maximum olecranon width was 26.9 mm. The ratio of the triceps tendon width to the olecranon width averaged 0.88. The mean thickness of the central tendon insertion was 6.8 mm. The medial triceps tendon showed a distinct, rolled medial edge and an insertion consistently confluent with the central tendon. The triceps footprint insertion was dome shaped. The mean insertional width and length of the tendon proper were 20.9 mm and 13.4 mm, respectively. The mean distance from the olecranon tip to the tendon was 14.8 mm. The tendon width, thickness, and insertional dimensions correlated with the olecranon width. Conclusions: The lateral triceps expansion is a consistent anatomic finding with a width that is approximately 70% of the width of the central tendon. The triceps insertion has a broad width and narrow thickness that expands distally and correlates with the size of the olecranon. Knowledge of this anatomy will help the surgeon optimize surgical approaches and triceps repair techniques.