Abstract
Purpose
Many TKA instruments were developed in these days. Distal femoral cutting guide using intra-medullary system were divided into two methods, from anterior or medial. Many companies employed anterior cutting guide, however these guides have a disadvantage of wide skin and quadriceps incision. Only Zimmer provided medial cut guide which performed short skin and quadriceps incision. However, reference point (medial femoral condyle) will be a risk of imprecise cutting for a medial condyle defect cases. We tried L-shaped new distal femoral cutting guide, reference point will be both femoral condyle and cutting from antero-medial side. The purpose of this study was to prove usefulness of the new guide.
Materials and Methods
Twenty-nine knees were employed in this study. All knees were treated with Optetrak knee system (Exactec). Surgical methods were as follows, mid line skin incision, short para-patellar deep incision, no patellar resurfacing, PS type implant and cement fixation were employed. 13 knees were used original anterior cutting guide (O group) and 16 knees were used new antero-medial cut guide (N group). Study items were length of skin incision, length of Quadriceps incision, surgical time, JOA score, and component tilting angles (implant position were compared to femoral axis with AP and lateral view of roentgenograms).
Results
Average skin incision was 11.7cm in O group and 10.6cm in N group. Average Quadriceps incision was 4.1cm in O group and 2.9cm in N group. There were significant difference in length of skin incision and length of Quadriceps incision. Average surgical time was 155min in O group and 147min in N group. Average component angles of AP view were 84 deg. in O group and 83 deg. in N group. Average component angles of lateral view were 99 deg. in O group and 99 deg. in N group. There were no significant differences between O group and N group in surgical time, component angles, amount of bleeding, and post surgical JOA scores.
Conclusions
New distal femoral cutting guide demonstrated same precise cutting compared to original guide. New distal femoral cutting guide achieved small skin incision and small quadriceps incision which is useful for MIS-TKA.