Clinical outcomes of intramedullary tibial guides in total knee arthroplasty: experience from a single-centre cohort.

BACKGROUND: The use of an intramedullary (IM) or extramedullary (EM) tibial cutting guide in total knee arthroplasty (TKA) is debated. This study critically analyses our experience using the IM tibial cutting guide for TKA. METHODS: This single-centre retrospective study included 369 patients who underwent TKA between January 1, 2023, and December 31, 2023. The data in the literature were analysed to evaluate the advantages and disadvantages of each of the two systems. The sample was radiographically assessed postoperatively to measure the medial proximal tibial angle (MPTA) and postoperative tibial slope (TS). RESULTS: The mean MPTA was 91.6°, with 24% of patients achieving an alignment within an acceptable margin of error of ± 1°. The mean TS was 4.3°, with 45% of patients exhibiting a TS between 4° and 5°. The mean tourniquet time was 25 min, and 4 of 369 patients (1.08%) required blood unit transfusions. No tibial fractures or fat embolism were reported. CONCLUSION: Our study demonstrates satisfactory outcomes using the IM tibial cutting guide for TKA, with excellent alignment in both coronal and sagittal planes, short operative times, and low transfusion rates. The lack of consensus in the literature highlights the need for further research to draw definitive conclusions on the optimal tibial cutting guide technique for TKA. LEVEL OF EVIDENCE: III.