Impact of posterior wall involvement and fixation on clinical and radiographic outcomes of associated both-column acetabular fractures: a systematic review and meta-analysis

Background: Posterior wall (PW) fractures are frequently associated with both-column (ABC) acetabular fractures. However, whether the presence of a PW fragment or the need for internal fixation affects prognosis remains a topic of debate. This study compared postoperative outcomes, including reduction quality and clinical results, according to the presence of an associated PW fracture and whether PW fixation was performed.Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. MEDLINE, Embase, and the Cochrane Library were searched for articles published up to December 10, 2025. Comparative studies of ABC fractures were included if they evaluated the presence or absence of PW involvement or compared internal fixation with nonfixation of the PW component. Clinical and radiographic outcome data were extracted.Results: Seven retrospective studies including 434 analyzable patients were included. No clear differences were found in the odds of poor reduction (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.43–1.94; P=0.80), osteoarthritis (OR, 1.04; 95% CI, 0.37–2.92; P=0.94), or conversion to total hip arthroplasty (OR, 0.63; 95% CI, 0.23–1.71; P=0.36) according to the presence of a PW fragment in ABC fractures. Among ABC fractures with PW involvement, nonfixation was associated with numerically higher odds of poor reduction than fixation, although the difference was not statistically significant (OR, 1.47; 95% CI, 0.46–4.76; P=0.52). In unadjusted comparisons of non-randomized cohorts, PW fixation was associated with significantly longer operative time (mean difference [MD], 70.38 min; 95% CI, 24.46–116.29; P=0.003) and greater intraoperative blood loss (MD, 351.36 mL; 95% CI, 244.97–457.74; P<0.00001). The final modified Merle d'Aubigné-Postel score did not differ significantly between the fixation and nonfixation groups (MD, 0.58 points; 95% CI, −0.57 to 1.74; P=0.32).Conclusions: Current evidence does not clearly support routine fixation of all PW fragments. In unadjusted comparisons of non-randomized cohorts, patients who underwent PW fixation had longer operative time and greater blood loss. These differences cannot be attributed to fixation itself because of confounding by indication and the frequent use of an additional posterior approach. Selective fixation based on residual displacement, joint congruency, and hip stability appears reasonable, although the certainty of evidence remains limited.Level of evidence: Not applicable.