Planning and repair of acetabular defects in revision total hip arthroplasty: Simple solutions for complex problems

Background: The increasing frequency of primary total hip arthroplasty (THA) has led to a rising incidence of complex revision hip arthroplasty (RHA). These procedures are frequently complicated by acetabular bone loss resulting from polyethylene wear-induced osteolysis or periprosthetic joint infection, which compromises primary implant stability and the restoration of physiological joint geometry. While various classification systems exist, there remains a clinical need for a reproducible, therapy-oriented framework to guide preoperative planning and intraoperative management.

Objective: This article describes the clinical application of the Acetabular Defect Classification (ADC) and its associated mobile web application to standardize the diagnostic and therapeutic approach to acetabular bone defects during revision surgery.

Key Points: The ADC categorizes defects into four main grades based on the integrity of the acetabular rim and load-bearing pelvic structures, with sub-classifications (A–C) denoting lesion location. Type 1 involves an intact rim, while Types 2 and 3 describe rim compromises of less than or greater than 10 mm, respectively. Type 4 represents pelvic discontinuity. A case report of a 67-year-old female demonstrates the longitudinal progression from a Type 1C defect, managed with impaction bone grafting and a Burch-Schneider cage, to a subsequent Type 3C defect. The latter required a modular support cup with macroporous titanium augmentation and an anatomical ileum tension band to bridge the structural rim defect.

Conclusion: The ADC system provides a standardized, algorithmic approach to RHA. By integrating radiographic assessment with a digital tool, surgeons can systematically identify defect severity and select appropriate biological or metallic augmentation strategies to restore hip biomechanics.