We retrospectively reviewed patients with hip posterior fracture-dislocation from the trauma registration of a level 1 trauma center from 2009 to 2019 to identify factors that might affect the success rate of CR in the ED. We included adult patients presenting with hip posterior fracture-dislocation who underwent the first CR attempt in the ED. Patients less than 18 years old or with a dislocated hip that had already been reduced before arrival at our ED were excluded from the study. The review process was approved by our institutional review board (no: 202101823B0), and the requirement for informed consent was waived owing to the retrospective nature of this study. The study was performed in accordance with the Declaration of Helsinki.

All patients followed the treatment protocol for hip fracture dislocation in our hospital. Initial resuscitation and primary survey were initiated upon arrival at our ED. For those who were unconscious and in a state of shock, complained of hip pain, and presented abnormal hip rotation and shortening of the lower extremities, a standard pelvic radiographic evaluation in the anteroposterior (AP) view was done. Once the hip joint dislocation was confirmed, the reduction was promptly performed.

For patients who had life-threatening conditions (head, chest, or abdominal injury) or other orthopedic emergencies (Gustilo type III open fracture, compartment syndrome, or active bleeding) that needed an immediate operation, the patient was sent to the OT directly for simultaneous operation and CR of the hip joint under general anesthesia.

However, if the patient had a stable hemodynamic status, CR was performed by an orthopedic surgeon at the bedside in the ED. Procedure sedation and analgesia with two medications, thiamylal sodium 300 mg (Citosol, Shinlin Sinseng Pharmaceutical Co. Ltd., Taoyuan City, Taiwan) and morphine HCl 10 mg (Bureau of Controlled Drugs, Taiwan Food and Drug Administration), were achieved intravenously. With adequate sedation and analgesia, reduction using different techniques was attempted. The reduction maneuver used was based on the preference of the in-charge orthopedic surgeon (senior orthopedic resident), mostly with a combination of the Allis, Lefkowitz, and Captain Morgan maneuvers [17]. Once the reduction was achieved, post-reduction pelvic radiography in the AP view of the pelvis was performed for confirmation. A three-dimensional reconstructed computed tomography scan of the hip was subsequently performed to better evaluate the presence of intra-articular osteochondral fragments, marginal impaction, and associated femoral head fracture for subsequent surgical planning.

If CR could not be achieved at the bedside within the therapeutic time of the sedation and analgesia, the patient was sent to the OT for reduction under general anesthesia, with endotracheal intubation and proper muscle relaxation. Fluoroscopy was also used sometimes to assist CR in the OT. If CR failed, OR was performed to reduce the dislocated hip. The Kocher–Lagenbeck approach was preferred to reduce the dislocated hip, and osteosynthesis was performed simultaneously. Occasionally, a greater trochanteric osteotomy was used to address the femoral head lesion.

We collected data including age, sex, body mass index (BMI), injury severity score (ISS), new ISS (NISS), time from injury to first reduction attempt (TIR), presence of associated femoral head fracture, posterior wall marginal impaction, and posterior wall fragment size (calculated with Moed’s method) [18]. Data were analyzed using SPSS software (version 26.0; SPSS Inc., Chicago, IL, USA). Continuous variables were compared using Student’s t-test, and categorical variables were compared using the chi-squared test and Fisher’s exact test. Statistical significance was set at a p value of < 0.05.