Autologous osteoperiosteal graft shows superior outcomes to bone graft in shelf acetabuloplasty for acetabular dysplasia : a rabbit model study.

Abstract

Aims: Endoscopic shelf acetabuloplasty (ESA) has been reported as an effective approach to prevent the progression of borderline developmental dysplasia of the hip (DDH), typically utilizing autologous iliac bone graft (BG) to address acetabular bone defects. However, BG fails to restore articular cartilage. Autologous osteoperiosteal grafting has shown promising results in repairing osteochondral defects, yet its application in DDH remains unreported. This study aimed to verify the efficacy of autologous osteoperiosteal graft (OPG) in ESA for DDH treatment in a rabbit model.

Methods: Acetabular dysplasia was induced in 30 female rabbits through six weeks of hindlimb cast immobilization. Subsequently, these animals were randomly allocated into three groups: 1) DDH group (no surgical intervention), 2) BG group (shelf acetabuloplasty with autologous bone grafting), and 3) OPG group (shelf acetabuloplasty with osteoperiosteal grafting). Another ten female normal rabbits served as controls. At four and eight weeks postoperatively, graft transformation and acetabular cartilage status were assessed via gross morphology, histology, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Acetabular coverage and subchondral bone quality of the acetabular roof was evaluated by micro-CT, while nanoindentation tests were performed to assess the biomechanical properties of regenerated tissues.

Results: Hyaline-like cartilage formation was found macroscopically and histologically in the OPG group while no cartilaginous tissue was detected in the BG group. qRT-PCR showed that the OPG group expressed more cartilage marker genes than the BG group. OPG-regenerated tissue achieved better biomechanical properties while no difference of improved acetabular coverage and subchondral bone quality was found in both graft groups. Moreover, OPG could alleviate acetabular cartilage degeneration much more significantly than BG macroscopically, histologically, and genetically.

Conclusion: Our study revealed that autologous OPG outperformed conventional BG shelf acetabuloplasty in a rabbit DDH model, suggesting its potential as a superior clinical option for DDH treatment during ESA surgery.