Journalartikel

Jahr der Veröffentlichung: 2021

Zeitschrift: Clinical Biomechanics

Bandnummer: 82

ISSN: 0268-0033

eISSN: 1879-1271

DOI Link: https://doi.org/10.1016/j.clinbiomech.2021.105283

Verlag: Elsevier

Abstract: 

Background: Revision reverse shoulder arthroplasty (RSA) poses considerable surgical challenges. We hypothesized that a newly developed press-fit stem, which is modeled on the medullary canal of the supracondylar region of the distal humerus by a slight distal bend, achieve both correct fit and sufficient primary stability and that additional distal fixation by interlocking screws is favorable in case of advanced humeral bone loss.

Methods: A modular tapered press-fit stem was implanted in 16 Sawbone humeri in three consecutively created defect situations (200 mm (experimental group type 31, 160 mm (type 4 degrees) and 120 mm (type 5 degrees) bone length above the epicondylar line. In experimental groups type 4 degrees and 5 degrees, additional distal interlocking screw fixation with one to three screws was tested. Primary stability was investigated by measuring micromotions with a high-precision rotational setup.

Findings: Highest relative micromotions were noted at the proximal end in experimental groups type 3 degrees and type 4 degrees, whereas in type 5 degrees highest micromotions could be seen at the distal end. Overall micmmotions were significantly lower in type 3 degrees and increased with extended defect size. In experimental group type 5 degrees, micro-motions increased with reduced additional distal screw fixation.

Interpretation: The examined press-fit stem did not provide sufficient primary rotational stability in all constructs without additional support. Advanced distal humeral bone loss had a strong impact on primary fixation. In experimental group type 5 degrees with 120 mm bone remaining, it might be beneficial to use three distal interlocking screws in the supracondylar region in order to neutralize torque and to avoid early loosening.

Harvard-Zitierstil: Jahnke, A., Mueller, F., Ulloa, C., Rickert, M., Werner, B. and Gohlke, F. (2021) Press-fit reverse shoulder arthroplasty in case of advanced humeral bone loss - Is additional distal fixation necessary for primary stability?, Clinical Biomechanics, 82, Article 105283. https://doi.org/10.1016/j.clinbiomech.2021.105283

APA-Zitierstil: Jahnke, A., Mueller, F., Ulloa, C., Rickert, M., Werner, B., & Gohlke, F. (2021). Press-fit reverse shoulder arthroplasty in case of advanced humeral bone loss - Is additional distal fixation necessary for primary stability?. Clinical Biomechanics. 82, Article 105283. https://doi.org/10.1016/j.clinbiomech.2021.105283