Abstract: A tibial prosthesis includes a base support member, a bearing surface member, a stabilizer insert support, and a shoulder screw. The base member has a centrally located proximally flared protrusion or rail which extends substantially from the anterior edge of the base support member to the posterior edge of the base support member and defines a pair of substantially parallel dovetail coupling edges. An upstanding posterior stop is located on the upper surface of the rail adjacent its posterior edge and a posteriorly angled screw hole is provided in an anterior portion of the rail. The bearing member has a lower distally tapered recess or groove, dimensioned to receive the rail on the base member, and a posterior stop receiving recess for permitting the posterior stop on the base member rail to engage the insert support. A hollow upstanding stabilizer is formed on a central portion of the bearing member and a hole is provided anterior of the stabilizer.