Cow-hitch-suture cerclage for fixation of the greater tuberosity in fracture RTSA

Florian Grubhofer, MD; Elias Bachmann, PhD; Christian Gerber, MD, FRCS; Karl Wieser, MD; Lukas Ernstbrunner, MD; Jon JP. Warner, MD; Samy Bouaicha, MD

JSES International (Mar 2021)

Cow-hitch-suture cerclage for fixation of the greater tuberosity in fracture RTSA

Florian Grubhofer, MD,
Elias Bachmann, PhD,
Christian Gerber, MD, FRCS,
Karl Wieser, MD,
Lukas Ernstbrunner, MD,
Jon JP. Warner, MD,
Samy Bouaicha, MD

Affiliations

Florian Grubhofer, MD: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland; Corresponding author: Florian Grubhofer, MD, Balgrist University Hospital, University of Zürich, 8008 Zürich, Switzerland.
Elias Bachmann, PhD: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland
Christian Gerber, MD, FRCS: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland
Karl Wieser, MD: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland
Lukas Ernstbrunner, MD: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland
Jon JP. Warner, MD: Massachusetts General Hospital, Department of Orthopedics, Harvard Medical School, Boston, MA, USA
Samy Bouaicha, MD: Balgrist University Hospital, Department of Orthopedics, University of Zürich, Zürich, Switzerland

Journal volume & issue: Vol. 5, no. 2
pp. 270 – 276

Abstract

Read online

Background: The treatment of complex proximal humerus fractures in the elderly with reverse total shoulder arthroplasty is an established treatment option. Healing of the greater tuberosity (GT) is associated with better outcomes. It was the aim of this cadaver study to compare the stability of GT refixation obtained with the so-called “cow hitch” cerclage fixation with that of the recommended standard suture cerclage technique. Methods: A 4-part proximal humerus fracture was created in 10 fresh-frozen, human cadaveric shoulders. A CT was performed preoperatively to ensure the comparability of bone density and fracture patterns. In the experimental group the GT was reattached to the stem of the reverse total shoulder arthroplasty with the “cow hitch” suture cerclage (CH) technique, the conventional (CON) technique recommended for the tested implant was used in the control group. Humeri were tested with a uniaxial material testing machine. In total, 5000 loading cycles with forces from 250 to 350N were applied while motion (in mm) of the tuberosities was recorded with a telecentric camera. Results: After 5000 loading cycles, the CH group showed a significantly smaller displacement of the bone fragment (0.74 ± 0.31 mm) than the CON group [2.29 ± 1.08 mm (P < .05)]. After the first three cycles the mean displacement was 0.14 mm (±0.12) in the CH and 1.42 mm (±0.21) in the CON (P < .0001) groups. Conclusions: GT reattachment with the “cow hitch” suture cerclage showed a significantly more stable fixation compared with the currently for the used prosthetic system recommended suture cerclage technique in an in vitro 4-part proximal humeral fracture model.

Published in JSES International

ISSN: 2666-6383 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Surgery: Orthopedic surgery; Medicine: Internal medicine: Specialties of internal medicine: Diseases of the musculoskeletal system
Website: https://www.journals.elsevier.com/jses-international

About the journal

Abstract

Keywords