Evaluation of Mg-3Zn biodegradable intramedullary pins in dogs with long bone fractures

The study was conducted on 10 dogs with long bone fractures, irrespective of age, sex and breed. All the cases were treated by internal fixation with Mg-based (Mg-3Zn) biodegradable pins and were evaluated for up to 60 days post-treatment. The physiological, haematogical and biochemical parameters were recorded and radiographic evaluation was made before surgery, immediately after surgery, and on 15^th, 30^th and 60^th day postoperatively to assess the effect of implantation of Mg-3Zn pins and bone healing. Physiological parameters were within the normal range for the entire period except for a significant decrease in the respiratory rate just after surgery. Mean values of Hb, TEC, DLC, PCV and platelets were within the normal range, but a significant decrease in the TLC was observed on 30^th and 60^th day after surgery. Mean values of serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase, urea nitrogen, creatinine, total proteins, albumin, globulin and albumin/globulin ratio, calcium, phosphorus, potassium, sodium, chloride and magnesium did not show any significant variations. Radiographically no severe adverse effect of Mg-based biodegradable pins was observed, except for production of gas and periosteal reaction at the fracture site, which subsided gradually with time. To conclude, Mg-3Zn intramedullary pins had no major adverse effect on physiological, haematological and biochemical parameters in dogs with satisfactory clinical outcome, but it needs improvement in alloying process to provide more strength to pins to avoid pin breakage and to reduce gas production.