DISTAL FEMUR FRACTURES TREATED WITH RETROGRADE FEMORAL NAIL

Objective: The aim of this study was to retrospectively review and evaluate the results of retrograde femoral nail for distal femur fractures with respect to range of knee flexion, early ambulation, and long term rehabilitation outcome including daily activities. Materials and Methods: We reviewed 44 fractures of distal femur (AO classification type 33) in 43 patients treated by retrograde femoral nail at our Trauma Hospital between 2011 and 2017. Fractures consisted of type A1 (n=20), type A3 (n=17), type C1 (n=5), and type C2 (n=2). There were 37 closed (84%), seven open (16%), and four pathologic (9.1%) fractures. Mean age of patients was 43.8years (range 16 to 83 year).The mechanism of injury was motor vehicle accident in 22 patients (51.2%),fall down in 12 patients (27.9%), and firearm injuries in 9 patients (20.9%). Associated fractures were seen in 14 patients (32.6%). Mean time to surgery was 7 days (range 2 to 15 days).Percutaneous technique was used in 39 (88.6%), and open technique used in 5 (11.4%) fractures. Functional outcome was assessed using the modified Hospital for Special Surgery knee scale. Relationship between clinical results and fracture type, surgical approach, and patient age were retrospectively reviewed. Results: Thirty eight patients were followed (38/43 with 39fractures) for a mean period of 24.8months (range 16 to 58 months). Average operating time was 115min?40 min. Four patients developed superficial infection, and one had deep infection, and 3 developed deep vein thrombosis. The mean time to union was 23 weeks (range 16 to 40 weeks). Delayed union was seen in four fractures (10.3%, more than 42 weeks). Five fractures (12.8%) required second surgery. The range of knee motion was normal in ten fractures (25.6%), 90?- 110? in 21 fractures (538%), 85? in five fractures (12.8%), and <85? in three fractures (7.7%). Using modified hospital for special surgery scale the results were excellent in11(28.2%), good in 14(35.9%), moderate in 10(25.6%), and poor in 4(10.3%) fractures.There were five fractures with varus deformity ( 12.8%, 10?), two with posterior angulation( 5.1%, 10?-15?), and two with loosening of distal and proximal locking screws, but no breakage of screws or nail failure. Conclusion: Retrograde femoral nail is good surgical option for distal femur fractures of type A and type C1, 2 AO classification.