Does measuring the medial gap before bone resection in total knee arthroplasty provide optimum gap adjustment and prevent bone recutting?

Abstract

This study aimed to demonstrate that measuring the medial gap before bone resection during total knee arthroplasty (TKA) provides an optimum gap adjustment in varus knees. In this study, patients were separated into two groups. Group 1 included patients whose medial joint gap was measured before bone resection and Group 2 included patients who underwent conventional technique without measuring. The medial joint gap was measured with a custom-made gap measuring device up to the point that the knee was corrected and aligned along its mechanical axis. Medial joint gap distances, distal medial femoral bone cut thicknesses, amounts of tibial resection calculated; gap internal distances measured after cutting and the thicknesses of the trial inserts were recorded. A comparison was made between the groups concerning the number of patients requiring an additional tibial bone cut and the distribution of insert thicknesses. Extra tibial bone resections were performed in two (5.7%) patients in Group 1 and 10 (28.6%) patients in Group 2. In Group 1, where the medial joint gap was measured, the need for an additional bone resection was statistically less (p=0.018). In comparing the distribution of insert size by group, the number of patients on whom an 8 mm insert had been used was significantly greater in Group 1 (p=0.024). The findings obtained in this study suggest that measuring the medial joint gap before bone resection in total knee arthroplasty may prevent repeated bone recutting and additional bone resections.