[Development and clinical application of an intramedullary controlled dynamic nailing]

To describe the design and application of a new intramedullary controlled dynamic nailing (ICDN).

The new ICDN was made of a stainless-steel alloy, consists of a nail shaft, inner rod, tensile screw, end cape and two interlocked screws. From December 2005 to February 2007, 48 cases of femoral shaft fractures were treated with ICDN. There were 16 females and 32 males with a mean age of 36. 6 years (range, 16-48 years). Injury was caused by traffic accident in 26 cases, falling from a height in 14, sports-related in 7 and crush injury in 1 case. According to Winquist classification, Thirty-seven cases were classified as type I (13 cases of type I-1, 23 cases of I-2 and 1 case of I-3), eleven as type I fracture ( 2 cases of type II-1, 8 cases of II-2 and 1 case of II-3). The time from injury to admission was an hour to a week. Emergency operation was performed in 19 cases and the other 29 patients were given operation within 3 days.

All cases were followed up for an average of 5 months (3-12 months). Among them, the average healing period was 21 weeks (8-26 weeks) and no nonunion, delayed union and breakage of nailings occurred. The complications included 2 infections, 5 pains, and 4 deformities. Based on Johner and Wrubs standard, the results were excellent in 39 cases, good in 7 cases and fair in 2 cases, The excellent and good rate was 95.8%.

ICDN has excellent biomechanical characteristics which can provide a flexible fixation in treating femoral shaft fractures. The operation is simple and is one of the good techniques in treating femoral shaft fractures.