A surgical resection guide comprising: a housing (36); a stylus arm (38) extending through the housing (36) and a linear adjustment mechanism. The linear adjustment mechanism comprises: a shaft (30) at least partially received within a bore extending through the housing (36) such that the shaft (30) can slide along its longitudinal axis relative to the housing (36), the shaft (30) incorporating a shaft tooth (50); and a dial (44) rotatably coupled to the housing (36) and incorporating a helical dial groove (48) defining a longitudinal axis offset from the longitudinal axis of the shaft (30). The shaft tooth (50) engages the dial groove (48) such that rotating the dial (44) relative to the housing (36) causes the shaft tooth (50) to slide along the dial groove (48) causing the shaft (30) to slide within the bore along its longitudinal axis. The housing (36) and the stylus arm (38) can rotate about the shaft (30) without causing the shaft (30) to slide within its bore along its longitudinal axis.