Efi Kazum1, Ofir Chechik1, Tamir Pritsch1, Gavriel Mozes1, Guy Morag1, Oleg Dolkart2, Eran Maman1. 1. Division of Orthopaedic Surgery, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Weizman Street, 6423906, Tel Aviv, Israel. 2. Division of Orthopaedic Surgery, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Weizman Street, 6423906, Tel Aviv, Israel. dolkarto@gmail.com.
Abstract
INTRODUCTION: A commonly used method of fixation of the transferred coracoid in the traditional Latarjet-Bristow procedure (open or arthroscopic) is by two bicortical screws. Although mechanically effective, screw fixation is also a major source of hardware and neurologic complications. This study aimed to compare the biomechanical performances of traditional metal screws and endobuttons as fixators of the Latarjet-Bristow procedure. MATERIALS AND METHODS: Nine fresh-frozen cadaveric human scapulae with the conjoined tendon attached to the coracoid process were used for the Latarjet-Bristow procedure. The specimens were randomly assigned one of two groups: fixation using two 4.5-mm cannulated partially threaded Latarjet-Bristow experience screws or fixation using a suture-button construct. Specimens were secured in a material testing machine and cyclically preconditioned from 2 to 10 N at 0.1 Hz for ten cycles. They were then pulled to failure at a normalized displacement rate of 400% of the measured gauge length per minute. The maximal load-to-failure, stiffness and stress were calculated using a custom script. The failure mechanism and site were recorded for each specimen. RESULTS: There were no significant differences in the maximal load-to-failure or other biomechanical properties of the two fixation techniques, but the failure mechanisms were unique to each one. Four specimens fixated with screws underwent graft failures (fracture) through the proximal or distal drill hole. Five specimens fixated with endobuttons underwent failure due to glenoid bone fractures. CONCLUSIONS: A single endobutton fixation appears to be biomechanically comparable to screw fixation in the Latarjet-Bristow procedure and provides a lower risk for graft fracture. Further studies with more numerous specimens are warranted to conclusively validate these findings.
INTRODUCTION: A commonly used method of fixation of the transferred coracoid in the traditional Latarjet-Bristow procedure (open or arthroscopic) is by two bicortical screws. Although mechanically effective, screw fixation is also a major source of hardware and neurologic complications. This study aimed to compare the biomechanical performances of traditional metal screws and endobuttons as fixators of the Latarjet-Bristow procedure. MATERIALS AND METHODS: Nine fresh-frozen cadaveric human scapulae with the conjoined tendon attached to the coracoid process were used for the Latarjet-Bristow procedure. The specimens were randomly assigned one of two groups: fixation using two 4.5-mm cannulated partially threaded Latarjet-Bristow experience screws or fixation using a suture-button construct. Specimens were secured in a material testing machine and cyclically preconditioned from 2 to 10 N at 0.1 Hz for ten cycles. They were then pulled to failure at a normalized displacement rate of 400% of the measured gauge length per minute. The maximal load-to-failure, stiffness and stress were calculated using a custom script. The failure mechanism and site were recorded for each specimen. RESULTS: There were no significant differences in the maximal load-to-failure or other biomechanical properties of the two fixation techniques, but the failure mechanisms were unique to each one. Four specimens fixated with screws underwent graft failures (fracture) through the proximal or distal drill hole. Five specimens fixated with endobuttons underwent failure due to glenoid bone fractures. CONCLUSIONS: A single endobutton fixation appears to be biomechanically comparable to screw fixation in the Latarjet-Bristow procedure and provides a lower risk for graft fracture. Further studies with more numerous specimens are warranted to conclusively validate these findings.
Entities:
Keywords:
Anterior shoulder instability; Endobutton; Glenoid bone loss; Latarjet–bristow; Shoulder
Authors: Guilherme Augusto Stirma; Leandro Massini Ribeiro; Evandro Dias Gaio; Paulo Santoro Belangero; Eduardo Antonio de Figueiredo; Alberto de Castro Pochini; Carlos Vicente Andreoli; Benno Ejnisman Journal: JSES Int Date: 2022-06-11