Summary AETOS Shoulder System is a metaphyseal, in-lay humeral platform that recenters on the anatomic neck cut, uses concentric humeral heads, and is delivered with a streamlined tray workflow for efficient anatomic and reverse shoulder arthroplasty. It is used for anatomic TSA with an anatomic 4-peg glenoid and for reverse RSA via the Meta Stem. Indications Indications primary anatomic total shoulder arthroplasty using AETOS anatomic glenoid with Meta Stem or Stemless humeral components reverse shoulder arthroplasty using AETOS reverse baseplate/glenosphere constructs with the AETOS Meta Stem stemless humeral prosthesis indicated for anatomic TSA only and not approved for reverse Contraindications active infection insufficient bone stock neuromuscular disorders Anatomy Osteology anatomic neck reference for head resection and in-lay collar seating set inclination and version on this plane greater and lesser tuberosities guide subscapularis approach (LTO/peel/tenotomy) and broach alignment protect GT during compaction and seating glenoid vault and inferior rim landmarks for pin placement angulator reaming trajectory Muscles subscapularis management LTO bony healing surface and robust repair adds steps for osteotomy and fixation peel preserves tendon footprint straightforward repair watch for tendon quality tenotomy quick exposure tendon-to-tendon repair consider length and tissue caliber Ligaments emphasizes coracohumeral ligament and anterior/inferior capsule partial preservation of posterior capsule can help centralize the humeral head during trialing Nerves axillary nerve at risk with inferior capsular work use blunt, low-profile retraction hugging the humeral neck musculocutaneous nerve avoid deep retraction medial to the conjoint tendon when releasing clavipectoral fascia and subcoracoid tissues Blood supply anterior humeral circumflex vessels encountered at the inferior subscapularis border encountered at the inferior subscapularis border coagulate or ligate early to reduce bleeding during inferior capsule release Approach Standard deltopectoral incision centered on the coracoid/anterior shoulder axis Technical Specifications Humeral Meta Stem four sizes (1–4) with an in-lay collar geometry for flush seating on the resection cruciate fins in A/P and M/L planes for metaphyseal stability Humeral heads AETOS Humeral Head Offerings Size Width Height Spherical ø 38-14 38mm 14mm 41mm 41-15 41mm 15mm 44.25mm 44-16 44mm 16mm 47.50mm 44-18 44mm 18mm 45.56mm 47-16 47mm 16mm 52.16mm 47-18 47mm 18mm 49.64mm 50-18 50mm 18mm 50mm 50-21 50mm 21mm 51.31mm 53-19 53mm 19mm 57.25mm 53-22 53mm 22mm 54.51mm Anatomic glenoid XS/S/M/L sizes standard and 5°/10° full-wedge posterior augments four pegs nine longitudinal flutes designed for cement interdigitation Posterior Augment Poly Thickness Specifications Glenoid base size 5° correction 10° correction XS 4.4mm 6.2mm S 4.8mm 6.4mm M 5.2mm 6.5mm L 5.6mm 6.8mm Baseplates centered, eccentric, and 10°/15° full-wedge shapes porous-coated fixation surfaces central post approximately 9 × 15 mm optional post extensions 10 or 15 mm (about 8.25-mm diameter) post extension options 8.25mm diameter available in 10mm & 15mm length Glenospheres 34/38/42-mm diameters in concentric or eccentric variants lateralization options +0/+3 mm 34-mm sphere also available with +1-mm lateralization Reverse liners and spacers standard or retentive liners in +0/+3/+6 mm +9mm spacer enables +9/+12/+15mm buildup anti-rotation tabs and positive stem lock-in features Screws Central screw 4.5mm diameter, available in 7 lengths Peripheral screw options 4.5mm screws in 8 lengths