High-resolution ultrasound tendon-to-bone distances in partial and complete finger flexor A2 pulley ruptures simulated in human cadaver dissection: toward understanding imaging of partial pulley ruptures

Xeber Iruretagoiena; Volker Schöffl; Ramón Balius; Marc Blasi; Fernando Dávila; Xavier Sala; Igor Sancho; Javier De La Fuente

doi:10.3389/fbioe.2023.1123857

High-resolution ultrasound tendon-to-bone distances in partial and complete finger flexor A2 pulley ruptures simulated in human cadaver dissection: toward understanding imaging of partial pulley ruptures

Front Bioeng Biotechnol. 2023 Jun 7:11:1123857. doi: 10.3389/fbioe.2023.1123857. eCollection 2023.

Authors

Xeber Iruretagoiena^{1

2

3}, Volker Schöffl^{4

5

6

7}, Ramón Balius^{8

9}, Marc Blasi¹⁰, Fernando Dávila¹¹, Xavier Sala^{12

13}, Igor Sancho¹, Javier De La Fuente¹⁴

Affiliations

¹ Deusto Physical TherapIker, Physical Therapy Department, Faculty of Health Sciences, University of Deusto, San Sebastián, Spain.
² Eskura Osasun Zentroa, Beasain, Spain.
³ Sputnik Investigación, Madrid, Spain.
⁴ Section Sportsorthopedics and Sportsmedicine, Department of Orthopedic and Trauma Surgery, Klinikum Bamberg, Bamberg, Germany.
⁵ Department of Trauma Surgery, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, Germany.
⁶ Section of Wilderness Medicine, Department of Emergency Medicine, University of Colorado School of Medicine, Denver, CO, United States.
⁷ School of Clinical and Applied Sciences, Leeds Becket University, Leeds, United Kingdom.
⁸ Consell Catala de l´Esport, Generalitat de Catalunya, Barcelona, Spain.
⁹ Sport Medicine and Imaging Department, Clínica Diagonal, Barcelona, Spain.
¹⁰ Department of Plastic Surgery, Hospital Germans Trias I Pujol, Barcelona, Spain.
¹¹ Orthopedics Department, Hospital Bidasoa, Irun, Spain.
¹² Anatomy and Embryology Department, School of Medicine, Universitat de Barcelona, Barcelona, Spain.
¹³ Department of Anesthesiology, Hospital Clínic de Barcelona, Barcelona, Spain.
¹⁴ Orthopedics Department, Clínica Pakea-Mutualía, San Sebastián, Spain.

Abstract

Introduction: The A2 pulley tear is the most common injury in rock climbing. Whereas complete A2 pulley ruptures have been extensively researched, studies focused on partial A2 pulley ruptures are lacking. A2 pulleys rupture distally to proximally. High-resolution ultrasound imaging is considered the gold-standard tool for diagnosis and the most relevant ultrasound measurement is the tendon-to-bone distance (TBD), which increases when the pulley ruptures. The purpose of this study was to establish tendon-to-bone distance values for different sizes of partial A2 pulley ruptures and compare these values with those of complete ruptures. Material and methods: The sample consisted of 30 in vitro fingers randomly assigned to 5 groups: G1, no simulated tear (control); G2, simulated 5 mm tear (low-grade partial rupture); G3, simulated 10 mm tear (medium-grade partial rupture); G4, simulated 15 mm tear (high-grade partial rupture); and G5, simulated 20 mm or equivalent tear (complete rupture). A highly experienced sonographer blinded to the randomization process and dissections examined all fingers. Results: The tendon-to-bone distance measurements (medians and interquartile ranges) were as follows: G1, 0.95 mm (0.77-1.33); G2, 2.11 mm (1.78-2.33); G3, 2.28 mm (1.95-2.42); G4, 3.06 mm (2.79-3.28); and G5, 3.66 mm (3.55-4.76). Significant differences were found between non-torn pulleys and simulated partial and complete pulley ruptures. Discussion: In contrast, and inconsistent with other findings, no significant differences were found among the different partial rupture groups. In conclusion, the longer the partial pulley rupture, the higher the tendon-to-bone distance value. The literature is inconsistent regarding the tendon-to-bone distance threshold to diagnose a partial A2 pulley rupture. The minimum tendon-to-bone distance value for a partial rupture was 1.6 mm, and tendon-to-bone distance values above 3 mm suggest a high-grade partial pulley rupture (15 mm incision) or a complete pulley rupture.

Keywords: A2 pulley; climbing; partial rupture; tear; tendon-bone distance; ultrasound.

Grants and funding

We acknowledge support by the Open Access Publication Fund of the University of Deusto. The funding body was independent of the design of the study and collection, analysis, and interpretation of data and of writing the manuscript.