Surgical instrument and end effector assembly thereof

An end effector assembly of a surgical instrument, comprising:

• a proximal body portion defining a longitudinal axis and comprising an articulating member and a firing member;
• a distal execution portion comprising a staple cartridge assembly and a staple anvil assembly, wherein opposing surfaces of the staple cartridge assembly and the staple anvil assembly form clamping faces for clamping tissue, and the distal execution portion is pivotally engaged to the proximal body portion through an articulation joint assembly, wherein the articulation joint assembly comprises:
• a proximal connecting member fixed to a distal end of the proximal body portion;
• a distal connecting member fixed to a proximal end of the distal execution portion, wherein the distal connecting member is engaged with the proximal connecting member, and the distal connecting member is provided with at least one articulation driving portion that is actuated by the articulating member to move so as to articulate the distal execution portion relative to the proximal body portion;
• and
• a retainer pivotally connected to the proximal connecting member and the distal connecting member, wherein the retainer is provided with a retaining channel for receiving the firing member.