Designing and clinical application of caps for intramedullary pinning to manage long bone fracture in dogs

Study was carried out to design and evaluate clinical application of caps for intramedullary pinning to mange long bone fractures in dogs. Cannulated cancellous caps made of 316 L stainless steel with dimensions of 10 mm x 25 mm (length) cap for 4 mm, 4.5 mm and 5 mm steinmann pin and 8 mm x 25 mm (length) cap for 2.5 mm and 3 mm steinmann pin were designed. A total of 14 cases of dogs presented with simple transverse, short oblique fractures of long bones were equally divided into groups A and B having 7 animals in each. Simple intramedullary pinning was done in group A, whereas, in group B designed caps were fixed at entry point at trochanteric fossa after intramedullary pinning to prevent proximal migration of pins. Posture, gait, perception of pain and lameness scores were assessed during 15, 30 and 60 day, postoperatively. Caps offered rigid fixation along with intramedullary pin resulting in mild or moderate callus formation. Excellent postoperative functional recovery without any pin migration, seroma formation and valgus limb deformity were observed in group B. Results of present preliminary study suggested that designed capped intramedullary pinning offers stable internal fixation and prevented pin migration, sciatic injury and seroma formation.