Computer navigated articulated cement spacers (IGS Prostalac) for infected total knee replacement

Abstract

INTRODUCTION: Two-stage revision total knee replacement with an interim articulated cement spacer is now the standard treatment for infected total knee replacement. However, this is a technically demanding operation because of potential significant issues with bone defects, lack of instruments for aligning the prosthesis and the limited range of sizes in the prostheses available. METHODS: We describe a technique for performing articulated functional spacer insertion under computer navigation by a modification of the workflow of a commercially available navigation system. Two cases are presented to illustrate the principle of the technique. The alignment of the implanted PROSTALACs in the postoperative long film of the lower limb was reported. RESULT: The application of computer navigation technique in PROSTALAC Total Knee Replacement significantly reduced the technical difficulty in correct implantation of the cement spacers. The alignment of the implanted articulated spacers were considered to be satisfactory as no outlier of more than 3 degrees were observed. CONCLUSION: A computer navigation technique which can be employed in performing implantation of an articulated cement spacer is described. The aims are to facilitate optimal implantation of the tibial functional spacer and to achieve the appropriate balance between the flexion and extension gap.