Screw fixation after tripe pelvic osteotomy is reliable: changes of acetabular correction are rare and do not correlate with risk factors

PURPOSE: The aim of this examination was to assess whether there is a change of acetabular correction after triple pelvic osteotomy (TPO) and if so, whether there is a correlation with patient-specific risk factors or with certain periods in the postoperative course. METHODS: A consecutive series of 241 TPO was reviewed retrospectively. The close-meshed radiographic follow-up of the first 12 weeks comprised pelvic radiographs performed immediately after the procedure, 5 days, 6 and 12 weeks after TPO. Three observers measured the lateral center edge angle, acetabular index and the craniocaudal offset of the pubic osteotomy. Patient-specific risk factors (e. g. age, gender, body mass index, nicotine abuse) and certain periods in the postoperative course were correlated with a change of acetabular correction. RESULTS: After application of the exclusion criteria, 225 hips were available for further examination. Intraclass correlation coefficient resulted in predominantly excellent agreement between the measurements of the three observers (0.74–0.91). In 27 cases (12%), the three observers agreed on a change of acetabular correction. In 18 cases (8%), there was a slight change, in 9 cases (4%), a relevant change. The latter entailed consequences in the postoperative aftercare. General equation estimation did not show any correlation between a change of acetabular correction and patient-specific risk factors or certain periods in the postoperative course (p = 0.79–0.99). CONCLUSION: Every once treated hip should be followed-up with the same attention, irrespective of the apparent risk profile. There is no rationale to skip a radiographic follow-up in the first 12 weeks after TPO.