RT Journal A1 Grimshaw, Charles S. A1 Moed, Berton R. T1 Outcomes of Posterior Wall Fractures of the Acetabulum Treated Nonoperatively After Diagnostic Screening with Dynamic Stress Examination Under Anesthesia JF The Journal of Bone & Joint Surgery JO The Journal of Bone & Joint Surgery YR 2010 FD December 1 VO 92 IS 17 SP 2792 OP 2800 DO 10.2106/JBJS.J.00112 UL http://dx.doi.org/10.2106/JBJS.J.00112 AB Update  This article was updated on December 23, 2010, because of a previous error. The sentence: "The widening of the joint space evident on this image was secondary to distraction by traction applied to the lower extremity during the examination", which incorrectly appeared in the legend to Fig. 1-D, now appears in the legend to Fig. 1-C.Background:  Dynamic stress fluoroscopy with the patient under general anesthesia has been advocated as a clinical measure of hip stability and congruity in patients with a posterior wall acetabular fracture. The purpose of this study was to establish the predictive value of the dynamic stress fluoroscopic examination for these fractures by evaluating clinical and radiographic outcomes after nonoperative treatment of fractures found to be stable with this examination.Methods:  Twenty-one consecutive patients with an acute posterior wall fracture of the acetabulum who were shown to have a stable hip joint by dynamic stress fluoroscopy while they were under general anesthesia were treated nonoperatively. At the time of follow-up, the patients underwent clinical and/or radiographic evaluation.Results:  Clinical follow-up was performed for eighteen patients at a minimum of two years after injury, at which time the average modified Merle d'Aubigné score was very good, with no one having less than a good clinical outcome. Fifteen of these eighteen patients had radiographic evaluation at a minimum of two years, and all were found to have a congruent joint with a normal joint space and no evidence of posttraumatic arthritis.Conclusions:  Hip joint stability determined with dynamic stress fluoroscopy with the patient under general anesthesia after a posterior wall acetabular fracture is predictive of hip joint congruity, an excellent radiographic outcome, and a good-to-excellent early clinical outcome after nonoperative treatment.Level of Evidence:  Prognostic Level IV. See Instructions to Authors for a complete description of levels of evidence.