A stapling device includes a shell assembly, an anvil retainer assembly, an anvil assembly, and a strain gauge. The shell assembly includes a housing including an inner housing portion that defines a through bore and supports at least one detection member or leg. The anvil assembly includes an anvil head and an anvil center rod having a boss. The at least one detection leg is positioned to engage the boss of the center rod to obstruct movement of the anvil assembly in relation to the shell assembly between an open position and a clamped position. The strain gauge is positioned to identify increased strain in the stapling device when the at least one detection leg engages the boss. This allows a clinician to confirm that an anvil assembly is properly attached to the stapling device prior to firing of the stapling device.
