Derotational distal femoral osteotomy for patients with recurrent patellar instability and increased femoral antetorsion improves knee function and adequately treats both torsional and valgus malalignment

• DOI: 10.1007/s00167-022-07150-9
• Publication Date: 2022-09-16T03:41:20Z
• Authors: Maximilian Hinz; Matthias Cotic; Theresa Diermeier; Florian B. Imhoff; Georg C. Feuerriegel; Klaus Woertler; Alexander Themessl; Andreas B. Imhoff; Andrea Achtnich
• Keywords: Genu Valgum

The aim of the study was to evaluate functional and radiological outcome following derotational distal femoral osteotomy (D-DFO) in patients with high-grade patellofemoral instability (PFI) an associated increased antetorsion (FA). It hypothesized that D-DFO would lead a good outcome, both torsional coronal malalignment could be normalized.Patients underwent between 06/2011 12/2018 for PFI FA (> 20°) were included. Patient-reported measures (Visual Analog Scale [VAS] pain, Kujala score, Lysholm International Knee Documentation Committee subjective knee form [IKDC], Tegner Activity [TAS]) evaluated pre- minimum 24 months postoperatively. Magnetic resonance imaging lower extremity weight-bearing whole-leg anteroposterior radiographs conducted change FA, limb alignment, PROMs tested statistical significance.In total, 27 (30 knees) aimed only correct (Group 1) or additionally perform varization 2) 14 cases each. In remaining two cases, double-level osteotomies performed additional tibial deformities. 25 (83.3%), concomitant procedures also addressing performed. At follow-up (38.0 [25-75% interquartile range 31.8-52.5 months]), significant reduction pain (VAS pain: 2.0 [1.0-5.0] vs. 0 [0-1.0], p < 0.05), improvement function (Kujala Score: 55.6 ± SD 13.6 80.3 16.7, 0.05; 58.6 17.4 79.5 16.6, IKDC: 54.6 18.7 74.1 15.0, increase sporting activity (TAS: 3.0 [3.0-4.0] 4.0 [3.0-5.0], = n.s.) reported. Femoral significantly reduced (28.2 6.4° 5.2°, 0.05). A observed Group 2 (2.4 1.2° valgus 0.3 2.4° valgus; one case, patellar redislocation occurred 70 postoperatively.In achieved function, as well adequate correction alignment.Retrospective case series, Level IV.