Ultrasonographic and radiographic assessment of uncomplicated secondary fracture healing of long bones in dogs and cats.

OBJECTIVES

To evaluate the use of ultrasonography (US) to detect bone healing in uncomplicated diaphyseal fractures of dogs and cats, and to compare these observations with detection of healing by radiography (RG).

STUDY DESIGN

Clinical study.

ANIMALS

Dogs (33) and cats (11).

METHODS

RG and brightness mode US were used to follow uncomplicated secondary fracture healing. Fractures were examined at admission and then every 2-4 weeks until healed or implant removal. Temporal differences in definitive detection of healed fracture by imaging technique were examined by species, patient age, bone, and fracture type.

RESULTS

US images obtained during uncomplicated secondary fracture healing were consistent with images of fracture healing described in humans. Mean time to US diagnosis of a healed fracture (mean 46 days) was significantly shorter than by RG (mean 66 days). Mean time until diagnosis of a healed fracture (US and RG) did not differ significantly between open and closed treatment. Patients </=7 months (n=9) healed significantly faster (P<.05) than animals aged 7-36 months (n=24) and animals >36 months (n=11), but there was no significant difference between the latter 2 groups. Diagnosis of a healed simple fracture by US was significantly quicker than for a comminuted fracture (P<.05), but no difference was noted when using RG.

CONCLUSIONS

US can be used to evaluate secondary fracture healing in biologically treated fractures in dogs and cats. US permits detection of a healed fracture earlier than RG.

CLINICAL RELEVANCE

Earlier diagnosis of a healed fracture by US can prevent unnecessarily long limb immobilization and allow earlier dynamization.