A novel stacked double-plate fixation with quadrilateral surface buttress screws for osteoporotic acetabular fractures in elderly patients: a prospective pilot case series study evaluating clinical and radiological outcomes

Acetabular fractures in the elderly present unique challenges due to osteoporotic bone, comminution, and frequent involvement of the quadrilateral surface (QLS) and anterior column. Conventional fixation often fails in this population, leading to hardware complications and secondary displacement. This prospective pilot study evaluates the clinical and radiological outcomes of a novel stacked double-plate technique combined with QLS buttress screws in geriatric patients. Twelve consecutive patients aged ≥ 70 years with displaced acetabular fractures involving the anterior column and QLS were treated between 2018 and 2022. All patients underwent the stacked double-plate technique with QLS buttress screws via a Modified Stoppa approach. Operative time, blood loss, complications, radiological reduction (Matta criteria), fracture union, and postoperative functional outcomes were prospectively recorded. The cohort included 12 patients (mean age 74 ± 5 years; range 70–85). Fracture patterns were anterior column with quadrilateral plate ( n = 6), associated both-column fractures ( n = 4), and transverse fractures ( n = 2). Mean operative time was 145 ± 18 min, and mean blood loss was 280 ± 65 mL. At a mean follow-up of 14 months (range 6–30), all fractures achieved union. Reduction quality was anatomical in 10 patients and satisfactory in 2. Final functional outcomes were favorable, with a mean HHS of 88 ± 5 (95% CI: 83–93) and mean total WOMAC of 12 ± 4 (95% CI: 8–16). No complications or hardware failures were observed. In this prospective pilot case series, the stacked double-plate technique with QLS buttress screws was feasible, provided stable fixation, and was associated with stable fixation and satisfactory functional outcomes in elderly patients with osteoporotic acetabular fractures. These preliminary findings should be interpreted cautiously due to the limited sample size, absence of a control group, and relatively short follow-up. Further studies with larger cohorts, comparative designs, and biomechanical validation are warranted.