Islandic horse Male castrated 8 years of age presented with a history of suspicious of P3 front left fracture 2 months ago. The diagnosis could not be confirmed, the horse was rested and treated with antiinflammatory drugs. No improvement in multiple subsequent re-examinations.The lameness was localised on the distal front left limb, radiographs of the region were taken. Radiographic examination Lateromedial (left), dorsal 65° proximal-palmarodistal oblique (right) and dorsopalmar (not shown) radiographic projections of the distal phalanx front left limb were taken. Radiographic findings
- There is a severe heterogenous opacity of the most distal part of the hoof horn with a radiolucent line at the level of the distodorsal region of the hoof horn (arrow).
- The solar margin of P3 is very irregular with asymmetrical and generalised peripheral widening of the vascular channels, asymmetrical crena and multiple identations (arrowheads). All in all the radioopacity of P3 is subjectively reduced.
- There is an additional irregularity of the solar marginin the lateral aspect of P3, with a thin lucent line and a separate fragment of bone opacity (empty arrow).
Close up of the two projections of P3 front left Radiographic diagnosis The radiographic diagnosis is:
- Bad quality of the hoof horn with horn defect
- Moderate to severe generalised pedal osteitis front left.
- Pathologic fracture fragment (fracture type 6) of the lateral P3.
For a better evaluation of the fracture fragments, 2 additional oblique views of P3 were taken. Dorsal 65°proximal 45° medial-palmarodistolateral (left) and dorsal 65° proximal 45° lateral-palmarodistomedial (right) view of P3. There is a better visualisation of the irregularity of the solar margin and a better delineation of the separated fragment laterally. Comments
- Pedal osteitis is defined as an inflammatory disorder of the distal phalanx .
- The disorder is a result of peristent inflammation of the foot.
- Since the third phalanx does not have a medulla, the bone inflammatory processes is labeled osteitis as opposed to osteomyelitis.
- The disorder is more commonly seen in front limbs since 60% of the horse‘s weight is distributed there.
- Involvement can be unilateral or bilateral, depending on the cause.
- There are two types of pedal osteitis, nonseptic and septic.
- Primar nonseptic pedal ostitis typically results from chronic sole bruising sustained from repeated concussion during excercise on hard surface. Secondary nonseptic pedal osteitis can be result of conformation faults or improper farrier work that have cause an uneven weight bearing on the sole.
- Typical radiographic findings are focal or generalized demineralization of the solar margin of the distal phalanx and widening of the vascular channels resulting in radiographic loss of the normally smooth border of the solar margin.
- Typically, bone demineralization will occur around the toe margin and irregular bone formation may be seen along the solar margin or the dorsal surface of P3.
- Severe cases of demineralization can weaken the bone margins and cause fractures of the distal phalanx.
- Gas may be present in the soft tissue adjacent to the surface of P3.
- The progression of healing of a P3 fracture is difficult to determine radiographically because of the minimal amount of external osseous callus produced by this bone.
- Solar margin fractures have a good prognosis if not associated with laminitis or severe pedal osteitis.
