A humeral trial and implant assembly for total shoulder arthroplasty comprising: a humeral fixation component including a primary bore, wherein the humeral fixation component is configured for fixation to a humerus; an adapter assembly including an adapter, the adapter including an adapter flange and a body portion extending from the adapter flange, wherein the body portion is received in the primary bore of the humeral fixation component; a humeral trial presenting a medial humeral trial face that has a bulbus shape and a lateral humeral trial face that defines a humeral trial cavity, wherein the humeral trial is coupled to the adapter assembly when the humeral trial and implant assembly is in a trialing configuration; a humeral implant presenting a medial humeral implant face that has a bulbus shape and a lateral humeral implant face that defines a humeral implant cavity, wherein the bulbus shape of the medial humeral implant face matches the bulbus shape of the medial humeral trial face, and wherein the humeral implant is coupled to the adapter assembly when the humeral trial and implant assembly is in an installed configuration; the adapter assembly including an adapter plate and an adapter fastener, the adapter plate coupled to the adapter, wherein the adapter plate and the adapter are discrete components, wherein the adapter plate is received in the humeral trial cavity when the humeral trial and implant assembly is in the trialing configuration, and wherein the adapter plate is received in the humeral implant cavity when the humeral trial and implant assembly is in the installed configuration, the adapter fastener coupling the adapter plate to the adapter, the adapter fastener including an adapter fastener head that is entirely covered by the humeral trial when the humeral trial and implant assembly is in the trialing configuration; a temporary connection releasably coupling the humeral trial to the adapter assembly that provides separation of the humeral trial and the adapter assembly without requiring disassembly of the adapter assembly; and a permanent connection fixedly coupling the humeral implant to the adapter assembly, characterised in that the adapter plate abuts the adapter flange, wherein the adapter fastener head tightens against the adapter plate. a humeral fixation component including a primary bore, wherein the humeral fixation component is configured for fixation to a humerus; an adapter assembly including an adapter, the adapter including an adapter flange and a body portion extending from the adapter flange, wherein the body portion is received in the primary bore of the humeral fixation component; a humeral trial presenting a medial humeral trial face that has a bulbus shape and a lateral humeral trial face that defines a humeral trial cavity, wherein the humeral trial is coupled to the adapter assembly when the humeral trial and implant assembly is in a trialing configuration; a humeral implant presenting a medial humeral implant face that has a bulbus shape and a lateral humeral implant face that defines a humeral implant cavity, wherein the bulbus shape of the medial humeral implant face matches the bulbus shape of the medial humeral trial face, and wherein the humeral implant is coupled to the adapter assembly when the humeral trial and implant assembly is in an installed configuration; the adapter assembly including an adapter plate and an adapter fastener, the adapter plate coupled to the adapter, wherein the adapter plate and the adapter are discrete components, wherein the adapter plate is received in the humeral trial cavity when the humeral trial and implant assembly is in the trialing configuration, and wherein the adapter plate is received in the humeral implant cavity when the humeral trial and implant assembly is in the installed configuration, the adapter fastener coupling the adapter plate to the adapter, the adapter fastener including an adapter fastener head that is entirely covered by the humeral trial when the humeral trial and implant assembly is in the trialing configuration; a temporary connection releasably coupling the humeral trial to the adapter assembly that provides separation of the humeral trial and the adapter assembly without requiring disassembly of the adapter assembly; and a permanent connection fixedly coupling the humeral implant to the adapter assembly, characterised in that the adapter plate abuts the adapter flange, wherein the adapter fastener head tightens against the adapter plate.