Radiographic changes of implant failure after plating for pubic symphysis diastasis: an underappreciated reality?

Abstract

Implant failure after symphyseal disruption and plating reportedly occurs in 0% to 21% of patients but the actual occurrence may be much more frequent and the characteristics of this failure have not been well described. We therefore determined the incidence and characterized radiographic implant failures in patients undergoing symphyseal plating after disruption of the pubic symphysis. We retrospectively reviewed 165 adult patients with Orthopaedic Trauma Association (OTA) 61-B (Tile B) or OTA 61-C (Tile C) pelvic injuries treated with symphyseal plating at two regional Level I and one Level II trauma centers. Immediate postoperative and latest followup anteroposterior radiographs were reviewed for implant loosening or breakage and for recurrent diastasis of the pubic symphysis. The minimum followup was 6 months (average, 12.2 months; range, 6-65 months). Failure of fixation, including screw loosening or breakage of the symphyseal fixation, occurred in 95 of the 127 patients (75%), which resulted in widening of the pubic symphyseal space in 84 of those cases (88%) when compared with the immediate postoperative radiograph. The mean width of the pubic space measured 4.9 mm (range, 2-10 mm) on immediate postoperative radiographs; however, on the last radiographs, the mean was 8.4 mm (range, 3-21 mm), representing a 71% increase. In seven patients (6%), the symphysis widened 10 mm or more; however, only one of these patients required revision surgery. Failure of fixation with recurrent widening of the pubic space can be expected after plating of the pubic symphysis for traumatic diastasis. Although widening may represent a benign condition as motion is restored to the pubic symphysis, patients should be counseled regarding a high risk of radiographic failure but a small likelihood of revision surgery. Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.