Background: Stemless humeral prostheses have been recently introduced. We measured for the first time their in vitro primary stability and analyzed the influence of three clinically important parameters (bone quality, implant size and post-operative loading) on micromotion. We also assessed if displacement sensors are appropriate to measure implant micromotion.
Methods: A stemless humeral implant (Sidus® Stem-Free Shoulder, Zimmer GmbH, Winterthur, Switzerland) was implanted in 18 cadaveric humeri. Three-dimensional motion of the implant was measured under dynamic loading at three load magnitudes with displacement sensors. Additionally, the relative motion at the bone-implant interface was measured with an optical system in four specimens.
Results: Micromotion values derived from the displacement sensors were significantly higher than those measured by the optical system (P<0.005). Analysis of variance (ANOVA) indicated that bone density (P<0.0005) and load (P<0.0001) had a significant effect on implant micromotion, however the effect of implant size was not statistically significant (P=0.123).
Interpretation: Micromotion of this stemless design was shown to be significantly dependent on cancellous bone density. Patients must therefore have adequate bone quality for this procedure. The influence of load magnitude on micromotion emphasizes the need for controlled post-operative rehabilitation. Measurements with displacement sensors overestimate true interface micromotion by up to 50% and correction by an optical system is strongly recommended.
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http://dx.doi.org/10.1016/j.clinbiomech.2015.12.004 | DOI Listing |
Shoulder Elbow
December 2024
Specialty Orthopaedic Upper Limbs Surgery Research Foundation, Bella Vista, NSW, Australia.
Background: This study aimed to determine the revision outcome between a centrally fixed stemless anatomic design and other total anatomic shoulder replacements using data from a large national arthroplasty registry.
Methods: The study period was from December 2011 to December 2022 and included three cohorts; primary Affinis stemless anatomic (AFS), all other primary total stemless anatomic (sTSA) and primary total stemmed anatomic shoulder arthroplasty (aTSA). The endpoint was all-cause revision using cumulative percent revision (CPR).
Curr Rev Musculoskelet Med
December 2024
Department of Orthopaedic Surgery, University of California San Francisco, 500 Parnassus Ave MU-320W, San Francisco, CA, 94143, USA.
Purpose Of The Review: There have been tremendous modifications to the humeral component since Paul Grammont first introduced the reverse total shoulder arthroplasty in 1985. The purpose of this article is to review historical design features and their drawbacks and to summarize the clinical outcomes of modern designs.
Recent Findings: Decreasing the neck-shaft angle and increasing humeral lateralization have helped address problems of scapular notching and limited internal and external rotation that were common with traditional designs.
Bone Joint J
November 2024
Division of Shoulder and Elbow Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Periprosthetic joint infection represents a devastating complication after total elbow arthroplasty. Several measures can be implemented before, during, and after surgery to decrease infection rates, which exceed 5%. Debridement with antibiotics and implant retention has been reported to be successful in less than one-third of acute infections, but still plays a role.
View Article and Find Full Text PDFShoulder Elbow
October 2024
Department of Trauma and Orthopaedics, Aberdeen Upper Limb Unit, Woodend Hospital, Aberdeen, UK.
J Shoulder Elbow Surg
October 2024
Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), Adelaide, SA, Australia; Department of Orthopaedics, University Hospital Geelong, Barwon Health, Geelong, VIC, Australia; Barwon Centre for Orthopaedic Research and Education (B-CORE), St John of God Hospital and Deakin University, Geelong, VIC, Australia.
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