Patient specific instrumentation allow precise derotational correction of femoral and tibial torsional deformities

Background: Rotational malalignment deformities of the lower limb in adults mostly arise from excessive femoral anteversion and/or excessive external tibial torsion. The aim of this study was to assess the correction accuracy of a patient specific cutting guides (PSCG) used in tibial and femoral correction for lower-limb torsional deformities.Methods: Forty knees (32 patients) were included prospectively. All patients had patellofe-moral pain or instability with torsional malalignment for which a proximal tibial (HTO) or distal femoral (DFO) or a double-level osteotomy (DLO) had been performed. Accuracy of the correction between the planned and the postoperative angular values including femoral anteversion, tibial torsion, coronal and sagittal alignment were assessed after tibial and/or femoral osteotomy.Results: Forty knees were included in this study. In cases of HTO, the correction accuracy obtained with PSCG was 1.3 +/- 1.1 degrees for tibial torsion (axial plane), 0.8 +/- 0.7 degrees for MPTA (coro-nal plane) and 0.8 +/- 0.6 degrees for PPTA (sagittal plane). In cases of DFO, the correction accuracy obtained with PSCG was 1.5 +/- 1.4 degrees for femoral anteversion (axial plane), 0.9 +/- 0.9 degrees for LDFA (coronal plane) and 0.9 +/- 0.9 degrees for PDFA (sagittal plane). The IKSG was improved from 58.0 +/- 13.2 degrees to 71.4 +/- 10.9 (p = 0.04) and the IKSF from 50.2 +/- 14.3 to 87.0 +/- 6.9 (p < 0.001).Conclusions: Using the PSCG for derotational osteotomy allows excellent correction accu-racy in all the three planes for femoral and tibial torsional deformities associated with patellofemoral instability.Level of clinical evidence II, prospective cohort study.(c) 2022 Elsevier B.V. All rights reserved.