Sarah Ettinger1, Michael Schwarze2, Daiwei Yao1, Max Ettinger1, Leif Claassen1, Christina Stukenborg-Colsman1, Hajo Thermann3, Christian Plaass4. 1. Department of Foot and Ankle Surgery, Orthopaedic Clinic at DIAKOVERE Annastift, Hannover Medical School, Anna-von-Borries-Straße 1-7, 30625, Hannover, Germany. 2. Biomechanical Laboratory, Orthopaedic Clinic, Hannover Medical School, Hannover, Germany. 3. ATOS Clinic, Heidelberg, Germany. 4. Department of Foot and Ankle Surgery, Orthopaedic Clinic at DIAKOVERE Annastift, Hannover Medical School, Anna-von-Borries-Straße 1-7, 30625, Hannover, Germany. Christian@plaass.de.
Abstract
BACKGROUND: With ankle arthritis often affecting young patients, joint-sparing treatments instead of total joint replacement should be considered. Only a few implants were specially developed for supramalleolar osteotomies (SMOT). This study was performed to analyse the stability of different implants and their appropriateness for SMOT. METHODS: Twenty-five bone models (Sawbone Europe, Malmö, Sweden) were used for biomechanical testing. SMOT were performed as a uniplanar osteotomy, leaving 5 mm of lateral bone intact with a standardized gap of 8 mm. Five different plates commonly used for SMOT were assessed. For axial stability, the constructs were tested during 100 cycles for each load (150N and 800N) at a rate of 0.5 Hz. For rotational stability, each construct was subject to 100 cycles of 5 Nm torque at a rate of 0.25 Hz, performing three runs with an axial preload of 0N, 150N, or 800N. Ultimate axial load was performed for one-half and ultimate rotational load was performed for the other half of the constructs. In addition, the stiffness of the different constructs after failure was tested. RESULTS: All constructs showed high stability and could be tested until maximum cyclic load. There was no significant difference between the five plates, neither for stiffness (axial or rotational) nor for failure load (axial or rotational). One plate indicated superiority in axial failure testing without any significant difference. CONCLUSION: All implants could be tested until maximum load. The intact hinge apparently provides enough support to compensate for lower moment of inertia of some plates. LEVEL OF EVIDENCE: Not applicable.
BACKGROUND: With ankle arthritis often affecting young patients, joint-sparing treatments instead of total joint replacement should be considered. Only a few implants were specially developed for supramalleolar osteotomies (SMOT). This study was performed to analyse the stability of different implants and their appropriateness for SMOT. METHODS: Twenty-five bone models (Sawbone Europe, Malmö, Sweden) were used for biomechanical testing. SMOT were performed as a uniplanar osteotomy, leaving 5 mm of lateral bone intact with a standardized gap of 8 mm. Five different plates commonly used for SMOT were assessed. For axial stability, the constructs were tested during 100 cycles for each load (150N and 800N) at a rate of 0.5 Hz. For rotational stability, each construct was subject to 100 cycles of 5 Nm torque at a rate of 0.25 Hz, performing three runs with an axial preload of 0N, 150N, or 800N. Ultimate axial load was performed for one-half and ultimate rotational load was performed for the other half of the constructs. In addition, the stiffness of the different constructs after failure was tested. RESULTS: All constructs showed high stability and could be tested until maximum cyclic load. There was no significant difference between the five plates, neither for stiffness (axial or rotational) nor for failure load (axial or rotational). One plate indicated superiority in axial failure testing without any significant difference. CONCLUSION: All implants could be tested until maximum load. The intact hinge apparently provides enough support to compensate for lower moment of inertia of some plates. LEVEL OF EVIDENCE: Not applicable.
Authors: Filippo Migliorini; Alice Baroncini; Yasser El Mansy; Valentin Quack; Andreas Prescher; Max Mischer; Johannes Greven; Markus Tingart; Jörg Eschweiler Journal: BMC Musculoskelet Disord Date: 2021-03-06 Impact factor: 2.362
Authors: Julia Greenfield; Philipp Appelmann; Yoann Lafon; Karine Bruyère-Garnier; Pol Maria Rommens; Sebastian Kuhn Journal: Sci Rep Date: 2021-09-22 Impact factor: 4.379