Interfragmentary Stability Influences Healing of Intra-articular Fractures. A Radiographic Study of Canine Femoral Condyle Fractures Repaired with Lag Screws

D. J. Francis; K. A. Johnson

doi:10.1055/s-0038-1633231

Veterinary and Comparative Orthopaedics and Traumatology, Table of Contents

Vet Comp Orthop Traumatol 1990; 03(02): 71-77
DOI: 10.1055/s-0038-1633231

Original Research

Schattauer GmbH

Interfragmentary Stability Influences Healing of Intra-articular Fractures. A Radiographic Study of Canine Femoral Condyle Fractures Repaired with Lag Screws

D. J. Francis

^*From the Orthopaedic Research Laboratory, Department of Veterinary Clinical Sciences, University of Sydney, Sydney 2006, Australia

^**From the Department of Rheumatology, Royal North Shore Hospital, St. Leonards 2065, Australia

,

K. A. Johnson

^*From the Orthopaedic Research Laboratory, Department of Veterinary Clinical Sciences, University of Sydney, Sydney 2006, Australia

^***From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, 80523 USA

› Author Affiliations

Abstract

Summary

The influence of fracture stability on the healing of intra-articular fractures of canine medial femoral condyles repaired with lag screws was evaluated radiographically and at necropsy. In 14 dogs, one condylar fracture was repaired with stable interfragmentary compression using two 4.0 mm cancellous lag screws. In the contralateral stifle, the condylar fracture was apposed with a single 4.0 mm cancellous lag screw so that the bone fragments were unstable and had interfragmentary motion. In a control group (n = 4), an arthrotomy was performed and a lag screw inserted without creating a fracture in one stifle. In the contralateral stifle, a condylar fracture was created and not repaired.

Radiographically stable fracture gaps were slightly wider at one month than immediately post repair, but at two and three months were healed completely. Unstable fractures remained incompletely healed at one, two and three months. Osteophytes were detectable radiographically at three months. Unrepaired fractures remained completely unhealed and these joints had severe osteophyte formation at one month. At necropsy, all joints with intra-articular fractures had some osteophytes and erosion of the medial tibial plateau articular cartilage. It was concluded that interfragmentary compression was a critical factor in fracture healing and that lack of stability caused delayed union, osteophyte development and cartilage erosion.

A model was developed to permit the study of the healing of both stable and unstable condyle repair.

Key words

Intra-articular fracture - Lag screw fixation - Interfragmentary stability - Fracture healing - Radiology - Articular cartilage

Full Text

References

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