[Interlocking nailing of the femur--analysis of problems and errors based on 80 fractures].

A series of 79 patients with 80 femoral fractures stabilized by the Grosse-Kempf interlocking femoral nail system (Howmedica) were critically evaluated for the frequency of problems and technical mistakes during surgery. Problems with patient positioning were negligible. In patients with fractures at a suitable site, the Wittmoser table proved useful. Closed reduction should not be attempted at all costs: in borderline cases, open reduction should be given preference to prevent complications. Radiologically relevant problems included: twisted nails, 27.5% of all cases; broken nails, 2.5%; bent nails, 1.2%. Proximal screws were too long in 18.7%, too short in 1.5%, placed too far cranially in 29.6%, shifted (with damage to the thread) in 3.1%. Distal screws were too short in 11.7%, too long in 16.1%, protruding laterally in 2.9%, malpositioned in 1.4%; affected by ectopic calcifications in 4.4%, by cortical fragmentation in 8.8%, and loosing in 10.2%; both screws broke in one case. Technical mistakes during surgery were faulty assessment of the fracture pattern in 7.5%, a wrong impaction site in 23.7%, and bursting of the proximal fragment in 11.2%. Leg shortening was observed in 8% (16 mm, on average) and lengthening in 11.2% (6.2 mm, on average). Rotational malalignment was seen in 23 of 35 patients followed up clinically: inappropriate external rotation (12.5 degrees, on average) in 12 patients and inappropriate internal rotation (10 degrees, on average) in 11. Implant damage was seen in 8.7%. A breakdown of the complications by the operating surgeons involved clearly shows where the problems lies: 80 fractures were treated by 25 surgeons.(ABSTRACT TRUNCATED AT 250 WORDS)