TY - JOUR
T1 - Optimizing reverse shoulder arthroplasty component position in the setting of advanced arthritis with posterior glenoid erosion
T2 - a computer-enhanced range of motion analysis
AU - Keener, Jay D.
AU - Patterson, Brendan M.
AU - Orvets, Nathan
AU - Aleem, Alexander W.
AU - Chamberlain, Aaron M.
N1 - Publisher Copyright:
© 2017 Journal of Shoulder and Elbow Surgery Board of Trustees
PY - 2018/2
Y1 - 2018/2
N2 - Background Our study purpose was to determine the optimal glenoid and humeral reverse shoulder arthroplasty (RSA) component design and position in osteoarthritic shoulders with severe glenoid retroversion deformities. Methods Computed tomography scans from 10 subjects were analyzed with advanced software including RSA range of motion (ROM) analysis. Variables included glenoid component retroversion of 0°, 5°, 10°, 15°, and 20° and baseplate lateralization of 0, 5, and 10 mm. Humeral variables included 135°, 145°, and 155° angle of inclination (AOI) combined with variable humeral offset. Results Glenoid component lateralization had the greatest influence on ROM. In comparing each ROM direction among all lateralization options independently, there were significantly greater adduction, abduction, external rotation, extension, and flexion motions with progressively greater lateralization. Internal rotation motion was greater at 10 mm only. In analyzing the effects of glenoid version independently, no differences in adduction or abduction ROM were seen. With greater retroversion, decreased external rotation and extension motion was noted; however, greater internal rotation and flexion motion was seen with the exception of flexion at 10 mm of lateralization. For adduction, external rotation, and extension, a more valgus AOI resulted in less ROM at each progressively greater AOI independent of humeral lateralization. Internal rotation and flexion motions were greater with a more varus AOI but not significant between each inclination angle. Abduction ROM was maximized with a more valgus AOI. Humeral lateralization had no effect on ROM. Conclusions In the setting of RSA for advanced glenoid osteoarthritic deformities, optimal ROM is achieved with 10-mm baseplate lateralization and neutral to 5° of retroversion mated to a humeral implant with a varus (135°) inclination angle.
AB - Background Our study purpose was to determine the optimal glenoid and humeral reverse shoulder arthroplasty (RSA) component design and position in osteoarthritic shoulders with severe glenoid retroversion deformities. Methods Computed tomography scans from 10 subjects were analyzed with advanced software including RSA range of motion (ROM) analysis. Variables included glenoid component retroversion of 0°, 5°, 10°, 15°, and 20° and baseplate lateralization of 0, 5, and 10 mm. Humeral variables included 135°, 145°, and 155° angle of inclination (AOI) combined with variable humeral offset. Results Glenoid component lateralization had the greatest influence on ROM. In comparing each ROM direction among all lateralization options independently, there were significantly greater adduction, abduction, external rotation, extension, and flexion motions with progressively greater lateralization. Internal rotation motion was greater at 10 mm only. In analyzing the effects of glenoid version independently, no differences in adduction or abduction ROM were seen. With greater retroversion, decreased external rotation and extension motion was noted; however, greater internal rotation and flexion motion was seen with the exception of flexion at 10 mm of lateralization. For adduction, external rotation, and extension, a more valgus AOI resulted in less ROM at each progressively greater AOI independent of humeral lateralization. Internal rotation and flexion motions were greater with a more varus AOI but not significant between each inclination angle. Abduction ROM was maximized with a more valgus AOI. Humeral lateralization had no effect on ROM. Conclusions In the setting of RSA for advanced glenoid osteoarthritic deformities, optimal ROM is achieved with 10-mm baseplate lateralization and neutral to 5° of retroversion mated to a humeral implant with a varus (135°) inclination angle.
KW - B2 glenoid
KW - Reverse shoulder arthroplasty
KW - glenohumeral arthritis
KW - glenoid deformity
KW - lateralized glenoid
KW - range of motion
UR - http://www.scopus.com/inward/record.url?scp=85040457104&partnerID=8YFLogxK
U2 - 10.1016/j.jse.2017.09.011
DO - 10.1016/j.jse.2017.09.011
M3 - Article
C2 - 29332666
AN - SCOPUS:85040457104
SN - 1058-2746
VL - 27
SP - 339
EP - 349
JO - Journal of Shoulder and Elbow Surgery
JF - Journal of Shoulder and Elbow Surgery
IS - 2
ER -