[Experiences with a helical femoral nail (LFN®). A multicenter study].
BACKGROUND
Antegrade intramedullary nailing is the method of choice in most femoral shaft fractures. The trochanteric entry portal of classic femoral nails is in close proximity to the piriformis tendon, the gluteus minimus tendon, the obturator tendons, and the medial femoral circumflex artery. Nail insertion lateral to the tip of the greater trochanter may be more favorable but needs the use of a helical implant.


METHODS
Measurement of the reamer pathway through an entry point lateral to the superior trochanteric border was performed with a three-dimensional motion tracking sensor in human cadaveric femurs. These results provided a scientific rationale for the design of a helical femoral nail (LFN®). In a prospective multicenter study a total of 227 femoral shaft fractures were treated by nailing with the LFN. Patients were followed at 3 months (n=193) and 12 months (n=167).


RESULTS
The ease of defining the entry point and inserting the nail was rated as"very good and good" by 90% of the surgeons. Intraoperative technical complications included incomplete reduction (14%), additional iatrogenic fractures (6%), and difficulties in interlocking (3.5%). At the 1-year follow-up, delayed unions were seen in 10%, secondary loss of reduction in 3%, and deep infection in 1.8% of the patients. Angular malalignment of more than 5° was seen in 5%, mostly in valgus. A normal walking capacity was seen in 68% and normal active hip flexion in 45%.


CONCLUSIONS
The results obtained in this study during 1 year do not provide evidence for an advantage of the LFN over conventional antegrade femoral nails.
Sektion für Traumatologie, Berufsgenossenschaftliche Unfallklinik, Schnarrenbergstraße 95, 72076, Tübingen, Deutschland. jrether@bgu-tuebingen.de
J R
JR
Rether
J M
JM
Muñoz Vives
H J
HJ
Bail
M H
MH
Verhofstad
M
M
Blauth
J
J
Ljungqvist
D
D
Höntzsch
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails / Q000706:statistics & numerical data*; D002102:Cadaver; D019544:Equipment Failure Analysis; D005260:Female; D005264:Femoral Fractures / Q000453:epidemiology* / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation* / Q000706:statistics & numerical data*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control; D015995:Prevalence; D011474:Prosthesis Design; D020127:Recovery of Function; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult