Archives of Current Research International

The present study was undertaken to compare the clinical and radiographic outcomes of diaphyseal long bone fractures in dogs stabilized using positive profile end-threaded intramedullary (IM) pins and interlocking intramedullary nails (ILN). Twelve dogs presented with non–weight-bearing lameness due to diaphyseal fractures of the femur or tibia were randomly divided into two equal groups. Group I fractures were managed by open reduction and retrograde fixation with positive profile end-threaded IM pins, whereas Group II fractures were stabilized by open reduction and normograde application of interlocking intramedullary nails. Postoperative limb function was evaluated on days 7, 15, 30, and 60 using a standardized lameness scoring system, and fracture healing was assessed radiographically at corresponding intervals. Earlier toe-touching and initiation of weight-bearing were observed in Group II as early as the seventh postoperative day. Mean lameness scores were significantly lower (P < 0.05) in the ILN group compared to Group I at all postoperative intervals. By day 60, dogs in Group II showed complete functional recovery with no observable lameness, whereas mild residual stiffness persisted in a few animals of Group I. Radiographic evaluation revealed faster progression of fracture healing in Group II, with earlier periosteal proliferation and complete union characterized by absence of a radiolucent fracture line by day 60. Although Group I also achieved satisfactory union, comparatively greater periosteal callus formation and mild fragment compression were noted. No major complications such as implant failure or non-union were encountered. The findings indicate that interlocking intramedullary nailing provides superior stability and improved functional recovery compared to positive profile end-threaded IM pin fixation in canine diaphyseal fractures.