Influence of glenoid component design and humeral component retroversion on internal and external rotation in reverse shoulder arthroplasty: A cadaver study
Influence of glenoid component design and humeral component retroversion on internal and external rotation in reverse shoulder arthroplasty: A cadaver study
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DOI:
10.1016/j.otsr.2013.08.008
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发表时间:
2013-12-01
影响因子:
2.3
通讯作者:
Favard, L.
中科院分区:
文献类型:
--
作者:
Berhouet, J.;Garaud, P.;Favard, L.
Background: A common disadvantage of reverse shoulder arthroplasty is limitation of the range of arm rotation. Several changes to the prosthesis design and implantation technique have been suggested to improve rotation range of motion (ROM).Hypothesis: Glenoid component design and degree of humeral component retroversion influence rotation ROM after reverse shoulder arthroplasty.Material and methods: The Aequalis Reversed (TM) shoulder prosthesis (Tornier Inc., Edina, MN, USA) was implanted into 40 cadaver shoulders. Eight glenoid component combinations were tested, five with the 36-mm sphere (centred seating, eccentric seating, inferior tilt, centred with a 5-mm thick lateralised spacer, and centred with a 7-mm thick lateralised spacer) and three with the 42-mm sphere (centred with no spacer or with a 7-mm or 10-mm spacer). Humeral component position was evaluated with 0 degrees, 10 degrees, 20 degrees, 30 degrees, and 40 degrees of retroversion. External and internal rotation ROMs to posterior and anterior impingement on the scapular neck were measured with the arm in 20 degrees of abduction.Results: The large glenosphere (42 mm) was associated with significantly (P < 0.05) greater rotation ROMs, particularly when combined with a lateralised spacer (46 degrees internal and 66 degrees external rotation). Rotation ROMs were smallest with the 36-mm sphere. Greater humeral component retroversion was associated with a decrease in internal rotation and a significant increase (P < 0.05) in external rotation. The best balance between rotation ROMs was obtained with the native retroversion, which was estimated at 17.5 degrees on average in this study.Discussion: Our anatomic study in a large number of cadavers involved a detailed and reproducible experimental protocol. However, we did not evaluate the variability in scapular anatomy. Earlier studies of the influence of technical parameters did not take humeral component retroversion into account. In addition, no previous studies assessed rotation ROMs.Conclusion: Rotation ROM should be improved by the use of a large-diameter glenosphere witha spacer to lateralise the centre of rotation of the gleno-humeral joint, as well as by positioning the humeral component at the patient's native retroversion value. (C) 2013 Elsevier Masson SAS. All rights reserved.