Journal article
The influence of over-reaming on stem stability in reverse shoulder arthroplasty
Seminars in arthroplasty, Vol.30(2), pp.123-131
07/2020
DOI: 10.1053/j.sart.2020.07.002
Abstract
Contemporary cementless reverse total shoulder arthroplasty (RSA) systems utilize a range of interference conditions based on the geometric relationships between the system instrumentation and the prosthesis design. The impact of prosthesis/bone interference, however, on the primary stability of the stemmed humeral component has not been characterized. The aim of this study was to evaluate the effect of over-reaming, standard reaming, and use of an upsized stem on stem stability in press fit reverse shoulder arthroplasty.
Three-dimensional humeral models were generated from CT data of 59 non-arthritic shoulders. Each model was prepared following the intended surgical technique, including resection of the humeral head and reaming of the humeral canal, assuming 1 mm spacing in reamer diameters. The appropriate humeral stem (2 mm increments in distal stem diameter) was then placed to represent instances of over-reaming (increased distal clearance between stem and reamed bone), standard reaming, and use of an upsized stem. Finite element analysis was performed to predict the primary stability of the humeral stem subjected to expected loads in RSA.
Over-reaming was associated with both increased stem subsidence as well as stem-bone micromotion, as compared to standard bone preparation (P < 001). No significant differences in stem translation or stem-bone micromotion were found between standard bone preparation and use of an upsized stem. Over-reaming was associated with approximately 50% increased rotation of the stem following functional loading, as compared to stems placed using standard preparation or upsized stems.
Over-reaming of the humeral canal in cementless reverse shoulder arthroplasty results in increased micromotion and decreased primary stability of the humeral stem when subjected to loading representative of daily activities. Use of an upsized stem can recover the primary stability expected for standard reaming.
Biomechanical Study
Details
- Title: Subtitle
- The influence of over-reaming on stem stability in reverse shoulder arthroplasty
- Creators
- Jeff E. Bischoff - Zimmer Biomet, Corporate Research, PO Box 708, Warsaw, IN 46581-0708, USAOlivia C. O'Reilly - University of Iowa Hospitals and ClinicsJames V. Nepola - University of IowaBrendan M. Patterson - University of Iowa Hospitals and Clinics
- Resource Type
- Journal article
- Publication Details
- Seminars in arthroplasty, Vol.30(2), pp.123-131
- Publisher
- Elsevier Inc
- DOI
- 10.1053/j.sart.2020.07.002
- ISSN
- 1045-4527
- eISSN
- 1558-4437
- Language
- English
- Date published
- 07/2020
- Academic Unit
- Orthopedics and Rehabilitation
- Record Identifier
- 9984304706402771
Metrics
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