Due to limited funding, the study is now being withdrawn.

Acetabular roof was a crucial structure for maintaining the stability of hip joint; however, its important role was not especially emphasized in the Letournel-Judet classification system. Acetabular roof was segmented into the roof column and roof wall in Three-column classification and fracture in this area alone was defined as A3 injury. Radiographic data and functional outcome of A3 injury patients were reviewed to explore the characteristics and surgical strategy.

Fracture data, surgical incision, operation time, blood loss, fracture healing， Reduction quality，functional outcome，and relevant complications

Inclusion Criteria:

• 18-80 years, acute (<14 days) closed roof column/wall acetabular fractures (A3.1, A3.2 or A3.3) in Three-column classification, normal activity of the affected hip before the injury, received surgical reduction and internal fixation

Exclusion Criteria:

• open fractures, pathologic fractures, limited range of motion (ROM) of the hip joint before the injury, conservative treatment, risk factors affecting bone healing (such as smoking and metabolic diseases) and noncompletion of the two-year follow-up

Patients met the inclusion criteria were collected in this study.

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.