Influence of humeral position of the Affinis short® stemless shoulder arthroplasty system on long-term survival and clinical outcome

Agnieszka Halm-Pozniak; Christian Riediger; Elisabeth Kopsch; Friedemann Awiszus; Christoph H Lohmann; Alexander Berth

doi:10.1016/j.jse.2024.01.051

Influence of humeral position of the Affinis short® stemless shoulder arthroplasty system on long-term survival and clinical outcome

J Shoulder Elbow Surg. 2024 Mar 19:S1058-2746(24)00191-5. doi: 10.1016/j.jse.2024.01.051. Online ahead of print.

Authors

Agnieszka Halm-Pozniak¹, Christian Riediger², Elisabeth Kopsch², Friedemann Awiszus², Christoph H Lohmann², Alexander Berth²

Affiliations

¹ Department of Orthopaedic Surgery, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany. Electronic address: agnieszka.halm-pozniak@med.ovgu.de.
² Department of Orthopaedic Surgery, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany.

PMID: 38514008
DOI: 10.1016/j.jse.2024.01.051

Abstract

Background: The purpose of this study was to evaluate the influence of humeral position of Affinis short implant in stemless anatomic total shoulder arthroplasties (STSA) on clinical and radiological results and mid- to long-term survival in the treatment of primary osteoarthritis (OA) of the shoulder.

Methods: 80 patients treated with a stemless shoulder arthroplasty for OA of the shoulder were evaluated with a mean follow-up (FU) of 92 ± 14 months (range 69 to 116 months) by Constant (CS)-Score, Disability of Shoulder, Arm and Hand (DASH)-Score and active range of motion (ROM). Radiographic assessment for bone adaptations and humeral implant position was performed by plain X-rays. Determination of pre- and postoperative center of rotation (COR) was used to assess the restoration of the geometry of the humeral head. The appraisal of proper humeral component positioning was correlated with the functional outcomes. A Kaplan-Meier analysis was calculated, investigating the influence of humeral implant position compared to survival time. Complications were noted.

Results: The ROM (p < 0.001), CS-Score (p < 0.001) and DASH-Score (p < 0.001) showed significant improvements after surgery for the entire series. The COR restoration was anatomical in 75 % (n = 60) of all implants and in 25 % (n = 20) non-anatomical (pre- and postoperative COR deviation of 2.7 ± 1.8 mm vs. 5.1 ± 3.2 mm, p = 0.0380). The humeral component position did not affect the functional outcome whereas the ten-year unadjusted cumulative survival rate for the anatomic group was significant higher in comparison with the non-anatomical group (96.7 % vs. 75 %, p = 0.002). The radiological evaluation revealed minor periprosthetic bone adaptions in various forms without clinical significance or further intervention. No revision was necessary due to a failed fixation of the stemless humeral component.

Conclusions: Regarding primary OA of the shoulder, STSA derives excellent long-term survival and clinical outcome. These types of implants are able to restore the geometry of the humeral head. Non-anatomical reconstruction may influence the survival over a long-term period on different pathways. Further studies are necessary to elucidate the effect of humeral component position in STSA on functionality, pain and implant survival rate.

Keywords: Osteoarthritis; Outcome; Shoulder; anatomical position; center of rotation; stemless shoulder arthroplasty; survival.