25dkou432 10.3205/25dkou432 urn:nbn:de:0183-25dkou4324 Meeting Abstract El Kayali El Kayali Moses Kamal Dieter MKD

Charité Universitätsmedizin Berlin, Berlin, Deutschland

author Berndt Berndt Rosa R

Charité Universitätsmedizin Berlin, Berlin, Deutschland

author Gwinner Gwinner Clemens C author Pichler Pichler Lorenz L

Charité Universitätsmedizin Berlin, Berlin, Deutschland Medical University of Vienna, Vienna, Österreich

author German Medical Science GMS Publishing House

Düsseldorf

610 20251031 engl This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). M0634 432 Deutsche Gesellschaft für Orthopädie und Unfallchirurgie Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie Deutsche Gesellschaft für Unfallchirurgie Berufsverband für Orthopädie und Unfallchirurgie Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2025) Abstracts | Gelenkersatz – Knie Berlin 20251028 20251031 AB67-4334 TextObjectives and questions: Recommendations regarding the surgical modification of the medial posterior tibial slope (mPTS) in medial unicompartmental knee arthroplasty (UKA) vary. Most knee systems recommend a specific target mPTS. Given the high preoperative variability among patients undergoing UKA, this often results in a significant change of the patient’s mPTS. However, it remains unclear whether this change in mPTS impacts the coronal alignment, specifically the medial proximal tibial angle (MPTA).Material and methods: Pre- and postoperative radiographs of 96 patients undergoing conventional medial UKA using a knee system for which a postoperative mPTS of 7° is recommended, were analyzed. Pre- and postoperative mPTS and MPTA were measured on anterior-posterior and lateral radiographs by two observers and reported. Their difference as well as the difference between the mean postoperative mPTS and the target value of 7°, were tested for statistical significance using two-sided and one-sided Student’s t-tests. For further analyses cases were grouped regarding their pre- to postoperative mPTS change into cases with < 3° and cases with ≥ 3° mPTS change. The Pearson correlation coefficient was used to assess the correlation between changes in mPTS and changes in MPTA.Results: The mean mPTS was reported as 9.27° (SD, 3.41°) preoperatively and 7.25° (SD, 2.23°) postoperatively, with a mean change of -2.02° (SD, 3.84°; p < 0.001). Overall, 71.7% of cases had a postoperative mPTS within ± 2° of 7° without statistically significant difference between the mean postoperative mPTS and the target value of 7° (p = 0.797). With a mean preoperative MPTA of 85.39° (SD, 2.34°) and a mean postoperative MPTA of 84.12° (SD 2.55), UKA resulted in an average change in MPTA of -1.28° (SD, 2.55; p < 0.001). However, Pearson correlation coefficient revealed only a very weak correlation between the change in mPTS and the change in MPTA in all cases (r = -0.05), those with < 3° mPTS change (r = 0.13), and those with ≥ 3° mPTS change (r = -0.12).Discussion and conclusions: Targeted mPTS modification can be achieved and implies a significant change from preoperative mPTS values in patients undergoing UKA. However, the change in mPTS does not affect the change in MPTA. 0 0 0 0