A Post‐Traumatic Osteoarthritic Model of Hip Following Fracture of Acetabulum in Rabbit: A Preliminary Study by Macroscopic and Radiographic Assessment

Abstract

Objective To develop a post‐traumatic osteoarthritic model of hip following fracture of acetabulum in rabbit for revealing biochemical mechanism of post‐traumatic osteoarthritis. Methods A total of 36 mature male New Zealand white rabbits were equally divided into sham group (n = 12), non‐ORIF group (n = 12), and open reduction and internal fixation (ORIF) group (n = 12). Except for the sham group, rabbits had survival surgeries to create acetabular fractures of dorsal wall for simulating dashboard impaction mechanism. The ORIF group received open reduction and internal fixation, while fractures in the non‐ORIF group were left as displaced but transverse fracture and dislocation was reduced. Besides intraoperative appearance and postoperative recovery, macroscopic and radiographic characteristics of the hips were recorded and assessed by a radiographic scoring scale at 3 weeks, 6 weeks, and 6 months, respectively. Results Out of 24 modeled acetabula, 21 (87.5%) were pure dorsal wall fractures as proposed and the remaining three were associated fractures (dorsal wall plus transverse fracture) accompanied by dorsal dislocation or not. All hips were stable, and no sciatic nerve injury was observed. One rabbit in the ORIF group died of deep infection 4 days after surgery. Rabbits in the sham and ORIF groups returned to normal gait in 2 weeks, but animals in the non‐ORIF group suffered from limping and restricted movement. As the time progressed, the hips in the non‐ORIF group experienced progressive and severe degeneration which exhibited dramatically malformed and hypertrophic joints at 6 months, but the ORIF group maintained much better morphological structure. Corresponding to morphological changes, the average radiographic scores of the non‐ORIF group increased from 1.25 at 3 weeks to 2.75 at 6 months and showed statistically significant difference when compared to the sham group at all three time points (P = 0.011, 0.011, 0.015, respectively, <0.0167). Although the scores of the ORIF group showed apparent improvements (increased from 0.67 at 3 weeks to 2.00 at 6 months), there was no significant difference between the two modeled groups at all three time points. Conclusion The fracture model with high consistency and reproducibility showed progressive post‐traumatic osteoarthritic changes which could be improved by open reduction and internal fixation surgery and provided an alternative selection for investigating potential pathogenesis and pathology of post‐traumatic osteoarthritis following fracture of acetabulum.

A New Method for Creating Impact-Induced Intra-Articular Fractures in a Rabbit Model Induces Severe Post-traumatic Osteoarthritis

“…61 A recent description of an impact-induced acetabular IAF rabbit model shows great promise as a realistic research tool; however, the authors only qualitatively described the joint degeneration subsequent to the fracture injury. 65 Furthermore, a recent review article by Delco et al that summarized the differential response of ankle and knee cartilage to catabolic signals, upregulation of collagen and proteoglycan synthesis, water content, tissue composition, and mechanical behavior 66 draws into question the practice of translating findings from models of IAF in one joint to other joints. This work addresses these current shortcomings by describing a widely implementable, intermediate-sized IAF model that provides an ankle-specific, clinically realistic vehicle in which to study IAFs and identify new treatments to prevent future degeneration of fractured ankles in human patients.…”

Gliedmaßenfrakturen beim Kaninchen (Oryctolagus cuniculus f. domestica)

“…Anhand dessen wurde die Knochenintegrität, die Durchbauung des Frakturspaltes, etwaig vorhandenes Kallusgewebe sowie arthrotische Zubildungen beurteilt. Arthrotische Gelenksveränderungen wurden in Anlehnung an die Untersuchungen von Li et al [13] in 3 Stufen klassifiziert (geringgradig: vereinzelte osteophytäre Zubildungen bis hochgradig: prominente osteophytäre Zubildungen, Remodellierung der Gelenksflächen). Die Längenmessung der frakturierten Knochen sowie der Knochen der kontralateralen Gliedmaße erfolgte anhand der 3 D CT-Darstellungen in Anlehnung an die Messmethoden wie sie durch von den Driesch [14] für Säugetiere im Detail beschrieben wurden.…”

Pressure sensing mat as an objective and sensitive tool for the evaluation of lameness in rabbits

“…Therefore, different methods have been established to detect changes in gait after interventions on experimental animals, not only in orthopaedics but also in other research domains such as neurological science. Visual assessments using simple descriptions of optical observations, including locomotor rating scales as presented by Basso et al [10], play a meaningful role, as they are inexpensive, non-invasive and easy to perform by different examiners [8,11,12]. However, visual observations and assessments themselves turn out to be highly subjective and dependent on the circumstances [11,13].…”