To investigate the clinical value of trabecular metal augments in revision surgery for Paprosky typeⅢcomplicated acetabular bone defects, and evaluate the effectiveness in intraoperative stability, the acetabular rotation center reconstruction, and hip function improvement.

A retrospective analysis was conducted on patients with Paprosky typeⅢacetabular bone defects who underwent revision surgery at Zhejiang Provincial Hospital of Traditional Chinese Medicine between January 2016 and December 2022. Inclusion criteria: age≥18 years; total hip arthroplasty history requiring acetabular revision due to prosthetic loosening or osteolysis; radiographic confirmation of Paprosky typeⅢacetabular bone defects; complete follow-up data with a follow-up duration of at least 12 months. Exclusion criteria: active infection or unresolved previous periprosthetic joint infection; severe comorbidities precluding surgical tolerance; pathological fractures or tumor-related bone defects; incomplete clinical or radiographic data. A total of six patients were enrolled. Among them, three patients with typeⅢA defects underwent reconstruction using trabecular metal augments combined with a porous tantalum metal cup, while three patients with typeⅢB defects were treated with a cage combined with an augment. The vertical and horizontal offsets of the hip center relative to the anatomical hip center were measured, and implant stability was evaluated based on radiographic findings. Intraoperative blood loss, operative time, perioperative complications, and domain-specific Harris hip scores before surgery and at the final follow-up were recorded to assess clinical efficacy and safety. Statistical analysis was performed using paired t tests or the Wilcoxon signed-rank test as appropriate. Difference was considered statistically significant if P<0.05.

All the patients completed the follow-up. At the final follow-up, implant position remained stable, with no evidence of dislocation, screw breakage, or obvious migration, and radiographic findings indicated satisfactory osseointegration. The total Harris score increased from the (54.2±4.2) before operation to (86.9±3.0) at the final follow-up (t=12.18, P<0.01). Pain scores improved from (15.5±5.7) to (40.0±3.2) (t=9.36, P<0.01), and function scores improved from (31.8±5.3) to (39.0±4.5) (t=3.74, P<0.05). The vertical offset of the hip center decreased from (20.1±3.7) mm before operation to (6.9±2.5) mm at the final follow-up (t=8.47, P<0.01), while the horizontal offset decreased from (10.8±2.9) mm to (4.7±2.0) mm (t=6.92, P<0.01).

Augment provides effective mechanical support and favorable osseointegration in revision surgery for Paprosky typeⅢ complex acetabular defects, enabling subtype-specific reconstruction strategies across different Paprosky Ⅲ subtypes. Short- to mid-term follow-up outcomes were satisfactory.