Comparison of arthroscopy- and fluoroscopy-assisted minimally invasive approaches for acetabular fracture repair in dogs: An ex vivo study.

Objective: To describe and compare arthroscopy-assisted (AA) with fluoroscopy-assisted (FA) minimally invasive plate osteosynthesis (MIPO) for simple transverse acetabular fractures.

Study design: Ex vivo cadaveric study.

Sample population: A total of 10 canine cadavers (>20 kg) without coxofemoral joint disease.

Methods: Pelvic computed tomography (CT) images were mirrored and three-dimensional (3D) printed to create models for precontouring 2.7-mm locking compression plates (LCP). Acetabula were randomly assigned to AA or FA MIPO groups and pelvis were prepared for stabilization by standardized osteotomies of the pubic, ischial and acetabular bones. In the AA group, fracture reduction was arthroscopically confirmed, and precontoured plates were applied via small approaches to the ilium and ischium. In the FA group, reduction was guided fluoroscopically. Surgical time, incision length, procedural complications, and feasibility were recorded. Postprocedural CT scans measured fracture gap, step formation, medio-lateral displacement and pelvic angulation. Necropsy assessed iatrogenic injuries.

Results: MIPO was successful for all 20 acetabula. Mean procedure time and incision length were not significantly different between groups. Mean fracture gaps and step defects were <1 mm in both groups. Medio-lateral displacement exceeded 1 mm in the FA group (median 1.08 mm) compared to 0.74 mm in the AA group. Low coronal angles (<5°) were consistent across procedures. Sciatic nerve injury occurred in one case per group. Minor superficial cartilage damage was common.

Conclusion: Arthroscopy-assisted MIPO was feasible for simple acetabular fractures, resulting in anatomic (6/10) or near-anatomic (4/10) reductions.

Clinical significance: Further studies and clinical experience are necessary before recommending AA as an alternative for open approaches.