Surgical Approaches to the Canine Radius

Kenneth A. Johnson, MVSc, PhD, FACVSc, DACVS, DECVS

Following surgical exposure and open reduction, antebrachial fracture stabilization is frequently achieved by the application of a bone plate on the cranial surface of the radius. To accomplish this fracture repair, the surgeon has a choice between two different surgical approaches: the craniolateral approach and the craniomedial approach. Both approaches are intended to provide exposure of most of the cranial surface of the radius, although a quantitative comparison has hitherto been lacking. The study by Lin and colleagues published in this issue of the Journal found that the craniolateral approach exposed a greater total area of cranial cortex of the radius than did the craniomedial approach.[1] Furthermore, a greater width of the bone could be exposed proximally with the craniolateral approach. The authors considered that the muscle belly of extensor carpi radialis could be more easily retracted medially with the craniolateral approach. However, they did acknowledge that the efficacy of muscle retraction, and the tissue trauma caused by such retraction, were impossible to quantify in this cadaveric study.

Although there are often two or more surgical approaches described for open reduction of fractures of most of the bones in the dog, most of these approaches are intended to expose different regions of the bone. Therefore, they are not readily comparable in the same way as the two cranial approaches to the radius.

Surgeons know that when performing a surgical approach to an intact or fractured bone, it is critical to minimize surgical trauma to the soft tissue attachments and blood supply to the bone, so that healing is not impaired. Normally the blood supply to the diaphysis of the radius is derived from the medullary arteries providing centrifugal blood flow from the endosteum to the periosteum.[2] In addition, numerous smaller blood vessels supply the cortex in regions of muscular attachment, and in the metaphyseal region. Loosely attached periosteum, such as those which exist on the cranial cortex of the radius, does not convey afferent blood vessels into mature cortical bone. Thanks to the research of Dr Fredric W. Rhinelander, an American orthopaedic surgeon, we know that disruption of the medullary blood supply by a diaphyseal fracture causes a transiently increased reliance on the vasculature in the muscular attachments to cortical bone.[2] The muscular insertions of the abductor pollicis longus and supinator and pronator muscles on the cranial cortex of the radius are relatively minor. The predominant blood supply to the fractured radius is derived from afferent blood vessels in the interosseus muscle and ligament. Care must be taken to preserve these caudal soft tissue attachments during fracture reduction and internal fixation. Rhinelander and colleagues showed that the medullary blood supply to the fractured canine radius was re-established within weeks, as healing occurred with bone plate stabilization.[2]

Since the pioneering research of Rhinelander, there have been great advances in the internal fixation of fractures, for example, locking plate stabilization of fractures. It is theorized, but not confirmed, that locking plates have less impact on periosteal blood supply to bone, but there is still much to learn about these new devices and their application.

Publikationsverlauf

Artikel online veröffentlicht:
13. Mai 2025

• References

• 1 Lin K-T, Degner DA, DeCamp CE. Does the craniolateral approach provide better exposure to the radius than the craniomedial approach for internal fracture fixation in dogs?. Vet Comp Orthop Traumatol 2025; 38 (01) 97-102
• 2 Rhinelander FW, Wilson JW. Blood supply to developing, mature, and healing bone. In: Sumner-Smith G. ed. Bone in Clinical Orthopaedics: A Study in Comparative Osteology. Philadelphia: WB Saunders Company; 1982: 81-158