Background: The optimal fixation technique in periacetabular osteotomy (PAO) remains controversial. Modified fixation with Kirschner wires (K-wires) was described as a feasible and safe alternative. However, clinical follow-up of patients treated with this technique is lacking. Aims: To assess patient-reported outcomes (PROMs) in patients treated with PAO with the K-wire fixation technique and to compare it with the screw fixation technique. Methods: We conducted an analysis of 202 consecutive PAOs at a single university center between January 2015 and June 2017. A total of 120 cases with complete datasets were included in the final analysis. PAOs with K-wire fixation (n = 63) were compared with screw fixation (n = 57). Mean follow-up was 63 ± 10 months. PROMs assessed included the International Hip Outcome Tool (iHOT 12), Subjective Hip Value (SHV), and UCLA activity score (UCLA). Pain and patient satisfaction (NRS) were evaluated. Joint preservation was defined as non-conversion to total hip arthroplasty (THA). Results: Preoperative baseline PROMs in both fixation groups were similar. In both groups, PROMs (p = <0.001) and pain (p = <0.001) improved significantly. Postoperative functional outcome was similar in both groups: iHOT 12 (71.8 ± 25.1 vs. 73 ± 21.1; p = 0.789), SHV (77.9 ± 21.2 vs. 82.4 ± 13.1; p = 0.192), UCLA (6.9 ± 1.6 vs. 6.9 ± 1.9; p = 0.909), and pain (2.4 ± 2.1 vs. 2.0 ± 2.1; p = 0.302). Patient satisfaction did not differ significantly (7.6 ± 2.6 vs. 8.2 ± 2.2; p = 0.170). Conversion to THA was low in both groups (two vs. none; p = 0.497). Conclusion: Periacetabular osteotomy with K-wire fixation provided good clinical results at mid-term follow-up, comparable to those of screw fixation. The technique can therefore be considered a viable option when deciding on the fixation technique in PAO.
