Extending the carpus results in internal rotation, and proximal translation of the radius relative to the ulna. Loading the carpus in extension decreases the internal and external rotation of the radius relative to the ulna. A better understanding of the interaction between the carpus and the elbow may improve our understanding of the pathogenesis of elbow dysplasia.

Objective: To describe bilateral mobilization of the superficial gluteal muscle (SGM) to treat ventral perineal hernias in dogs. Study design: Cadaveric study and short case series. Sample population: Male dog cadavers (n = 10) weighing between 5 and 42 kg and three dogs treated for ventral perineal hernia. Methods: Cadavers were positioned in right and left lateral recumbency to free the origin and insertion of the ipsilateral SGM except for muscle fibers originating on the first tail vertebra and sacrotuberous ligament. The dogs were placed in ventral recumbency to approach the perineum and rotate the muscle flaps. The insertions of the SGM were sutured together ventral to the anal sphincter muscle. The dorsal border of the overlapping tendons was sutured to the anal sphincter muscle, and the ventral border was sutured to the ischiourethralis muscle. The amount of overlap between bilateral flaps was measured. The SGM flaps were used to revise recurrent perineal hernias in three dogs. Results: Superficial gluteal muscle flaps were created without damage to the blood supply in all dogs. The overlap between the bilateral flaps ventral to the anal sphincter measured 0 to 2.4 cm. No recurrence was detected at follow-up (6-12 months) in the three dogs treated with these flaps. Conclusion: Superficial gluteal muscle flaps were mobilized without damage to the blood supply and crossed the midline ventral to the anal sphincter. Flaps were used successfully to repair ventral perineal hernias in three dogs. Clinical significance: Bilateral SGM flaps can be considered to repair ventral perineal hernias.

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Objective To evaluate the effect of the interosseous ligament and selected antebrachiocarpal ligaments on the internal rotation of the radius relative to the ulna, during carpal extension. Study Design Cadaveric study. Sample population Twenty‐four cadaveric canine forelimbs. Methods Twenty‐four forelimbs were disarticulated at the elbow joint and the antebrachia were prepared for testing. The forelimbs were divided to 6 groups, defined by the order in which ligaments were transected. All specimens were tested intact and after transecting each of the ligaments with the order defined by the group. Rotation of the radius relative to the ulna, caused by extension of the carpus, was measured using a sensor connected to the radius. Results: The mean(±sd) maximum internal rotation of the radius (5.94° ± (1.23°)) with all the ligaments intact was significantly greater (p < 0.012) than the mean(±sd) maximum internal rotation of the radius (3.13° (± 1.13°)) after transecting the interosseus ligament. Transecting the interosseous ligament subsequent to one of the other ligaments caused a decrease in internal radial rotation (p = 0.629), while, transecting the short radial collateral ligament caused an increase in radial rotation (p = 0.629). Transecting the palmar radiocarpal and ulnocarpal ligaments had no effect on radial rotation. Conclusion The interosseous ligament was stretched with internal rotation of the radius due to carpal extension. Carpal flexion resulted in external rotation of the radius. This effect was lost when the interosseus ligament was transected. Clinical Significance Rotation of the radius is associated with carpal extension, and is likely an intrinsic part of forelimb biomechanics.