[The comparisive study of the clinical effect of rotary self-locking intramedullary nail and intramedullary interlocking nail for the treatment of femur fracture].

Objective: To compare the clinical effect of rotary self-locking intramedullary nail (RSIN) and intramedullary interlocking nail (IIN) for the treatment of fresh femoral shaft fracture.

Methods: The radiological records of 60 fresh femoral shaft fractures (41 stable fractures and 19 unstable fractures) were retrospectively analyzed. Among them, 49 were male and 11 were female. The average age was 33.5 years old (range from 12 to 68 years old). All cases were fresh fracture with no important blood vessel or nerve injury, which were taken operation with RSIN on IIN respectively in 2 h-7 d after injury. The patients in IIN group began functional movements at postoperative 4 to 5 days and could bear the weight of 10-15 kg. The patients in RSIN group could began functional exercises after the wound healed and bear partly weight after 6 weeks. Both groups were contrasted on the biomechanics, operation procedure, fracture healing time, functional recovery and operative indication.

Results: Both groups were followed-up for average 13 months. IIN group: the average healing time of closed femur fracture was 16 weeks while that of open fracture was 20 weeks. The healing rate was 100% and the malunion rate was 7.9%. The excellent and good rate of functional recovery was 93.3% including excellent in 27 cases, good in 1, fair in 1 and bad in 1. RSIN group: the average healing time of closed femur fracture was 16 weeks while open fracture was 23 weeks. The healing rate was 87% and the malunion rate was 18.2%. The excellent and good rate of functional recovery was 83.3% including excellent in 23 cases, good in 2, fair in 3 and bad in 2. No implant break and nonunion happened. The differences between two groups in healing time, deformity-union rate and the rate of the twice operation were statistically significant.

Conclusion: IIN provides a reliable and practical alternative method for the treatment of all kinds of femoral shaft fracture and its important complication is fewer than RSIN group. RSIN also has a good curative effect in its own indication.