Periosteal transection and stripping for treatment of angular limb deformities in foals: radiographic observations.

This study explored the use of periosteal transection and periosteal stripping in the treatment of angular limb deformities in foals. The researchers assessed the radiographs of 23 foals (35 forelimbs) prior to and following surgery, and found that the majority of foals became sound with straight limbs despite the severity of deformity or changes in the shape of the carpal bones.

Overview of the Research

• The researchers carried out a thorough examination of the radiographs of 23 foals (amounting to 35 forelimbs) affected by carpal region angular limb deformities. These deformities were later corrected through a surgical process called hemicircumferential transection of the periosteum and periosteal stripping.
• The evaluation of these radiographs focused on geometric and morphologic abnormalities. Geometric measurement variables included the deviation angle (the angle of the deformity) and the deviation pivot point. Morphologic abnormalities were classified into several categories including: asymmetric width of the distal radial physis, asymmetric width of the distal radial epiphysis, carpal bone collapse or fracture, carpal bone hypoplasia (underdeveloped carpal bone), carpal bone displacement (out of position bone), and metacarpal bone displacement.

Results

• They observed that 57% of the limbs had radiographic lesions in the carpal joints while 20% had such lesions in the metacarpus (the middle section of the limb).
• Of all the limbs, 48% exhibited carpal or metacarpal bone hypoplasia, 26% had carpal or metacarpal bone displacement, and 12% bore traces of carpal bone collapse or fragmentation.
• In the long-term follow-up, which spanned from 5 months to 2 years, 83% of the foals were perfectly sound with straight limbs, irrespective of the severity of the deviation angle, the position of the deviation pivot point, or the morphologic changes of the carpal bone.
• 60% of the foals were in performance training, and about half of these had recorded carpal bone hypoplasia before deviation correction.

Conclusion

• The research concluded that a thorough geometric and morphologic radiographic interpretation should be conducted before implementing surgical correction of carpal angular limb deformities through hemicircumferential transection of the periosteum and periosteal stripping.
• However, the presence of severe deviation angle, distal location of the pivot point, or the occurrence of epiphyseal, carpal bone, or metacarpal bone changes should not deter the attempt at surgical corrections. In other words, such conditions do not necessarily affect the positive outcome of the surgery.