Evaluation of End-threaded Positive & Negative Profile Intramedullary Pins for Management of Long Bone Fractures in Dogs

Abstract

The present study was planned to evaluate the efficacy of positive and

negative profile end threaded intramedullary pins in the management of long bone fractures in dogs and to compare the positive profile and negative profile end threaded intramedullary pins for management of long bone fractures in dogs. Eleven clients owned dog suffering from fracture of long bones were randomly divided in to two groups. Animals of group I (n=5) & group II (n=6) were treated with end threaded positive & negative profile intra medullary pin, respectively. Various pre-operative, intraoperative & postoperative observations were recorded and the data generated was analyzed using standard statistical procedure. History was taken & clinical examination along with the radiographic examination was done to record various parameters like age, sex, breed, time since fracture, cause of fracture, type & location of fracture, bone involved. The intramedullary pinning was done using 3 to 5.5 mm diameter pins under general anesthesia using end threaded intra medullary pin (positive & negative profile). The time taken for surgery, size of end threaded intramedullary pin used was noted down. Radiographs were taken preoperatively, immediately after fixation and then at regular intervals till signs of radiographic healing were evident. Dogs of different breed German shepherd (n=4), Non-descript (n=4), Labrador (n=1), Boxer (n=2) were reported with Mean ± S.E. age of 13.73 ± 4.80 months and Mean ± S.E. weight as 17.26± 1.77 Kg; out of which six were male & five were female dogs and road traffic accident (RTA) being the most common etiology for fracture. Femur (n=6), tibia (n=3), humerus (n=1) & radius (n=1) were affected; with majority being simple/closed (n=10) fractures. Of all the fractures

recorded, 5 fractures were mid diaphyseal transverse fracture, 2 were distal 1/3rd diaphyseal transverse fracture, 3 were proximal 1/3rd diaphyseal slight oblique fracture and 1 was mid diaphyseal oblique fracture There was no significant difference between the two groups in terms of time taken for fixation/surgery and in healing time. There was a gradual improvement in weight bearing postoperatively in both the groups. An animal in group I showed signs of non-union due to late presentation (due to COVID-19 outbreak) and another case of lameness showed improvement after the intramedullary pin was removed from the tibia post healing. There was mild periosteal callus formation in all the cases when observed radiographically and the pins were removed after radiographic healing was evident in an anticlockwise manner using Jacob’s chuck & key, under mild sedation. There was no complication like implant failure or pin tract sepsis or pin migration in any of the cases of two groups. The end threaded intra medullary pin (both positive and negative profile) may well be replaced in place of simple steinmann intra medullary pin as these have better biomechanical stability, are easily available, economical with minimal complications and can be very useful especially in the field conditions; provided a proper diameter pin is used