Emergency Clinical Hospital of Constanta, Romania Mechanical failure of femoral intramedullary nail with proximal junction breakage: a series of 5 cases and review of literature Obadă B., Șerban Al. O., Costea D., Grasa C., Zekra M., Alecu Silvana-Crina Emergency Clinical Hospital of Constanta, Romania P242 Introduction Proximal femoral fractures are a common fragility injury in the elderly osteoporotic population. Surgical treatment is mandated as it fastens recovery and ambulation, and it reduces mortality. Intramedullary nails (IMN) are increasing in popularity in unstable intertrochanteric fractures due to their safety profiles, low complication rate and short surgical time. However rare, nail breakage is a described complication and its incidence ranges from 0,2% to 5,7%. Objective We present a case-series of mechanical failure and proximal breakage of these nails and review their operative condition, associated risk factors, presentation, treatment and surgical outcome. Methods Between June 2013 and June 2015, 590 patients underwent closed reduction and internal fixation with IMN in our hospital for proximal femur fractures. During this time period we revised three cases for IMN breakage. Two additional cases were referred from outside institutions. Preoperative assessment included clinical, laboratory and imaging findings. Out of the five patients, four were females (mean age 78,6 years). Four had an intertrochanteric fracture (Kyle III and Kyle IV); two with a short nail. A fifth patient had a subtrochanteric fracture that was also fixated using a long IMN (Table 1). An adequate fracture reduction was obtained in all but one patient prior to breakage. All has associated morbidities like osteoporosis or diabetes. They all reported feeling a sudden thigh pain with no preceding fall or trauma. Results Breakage occurred at the nail junction with the lag screw in all cases. One patient had also broken the proximal screw and two patients also had a broken distal screw. Time breakage ranged from 3 month to 1 year after primary implantation. In our series the most common cause of nail breakage was metal fatigue secondary to union delay or nonunion. Three patients were rescued using a new IMN, and two with total hip arthroplasty. Broken IMN were removed using a smooth guidewires and cultures obtained during the revision surgery were all negative. After an average of 12-month follow-up, all patients had resumed ambulation with no major complication reported. Conclusions IMN breakage, although rare, is being increasingly reported in the literature. Main reported risk factors are those that increase mechanical fatigue and delay bone union, such as improper fracture reduction, poor surgical technique or increasing patient`s comorbidities. IMN design and material used may also favor failure. Knowledge of these factors can help surgeon prevent the occurrence of this rare complication and assist in the improvement in nail design.