Angular malalignment after intramedullary nailing of femoral shaft fractures.
OBJECTIVE
To determine factors associated with angular malalignment of femoral shaft fractures treated with intramedullary nails and to determine differences in the incidence of angular malalignment based on fracture location, fracture comminution, and method of treatment (i.e., antegrade or retrograde).


METHODS
Retrospective.


METHODS
Level I trauma center.


METHODS
Three hundred sixty patients with 374 femoral shaft fractures were identified from a prospectively obtained orthopaedic trauma database. Complete sets of immediate postoperative anteroposterior and lateral radiographs were available for 355 (95 percent) of the 374 fractures.


METHODS
Patients were treated with antegrade (183 cases) or retrograde (174 cases) intramedullary femoral nailing.


METHODS
Goniometric measurements were made on all immediate postoperative radiographs to determine the coronal plane and sagittal plane angular alignments. A multiple linear regression statistical analysis was used to determine factors associated with increasing angular malalignment. The incidence of malalignment was determined using more than 5 degrees of deformity in any plane as the definition of malalignment.


RESULTS
Proximal fracture location, distal fracture location, and unstable fracture pattern were associated with increasing fracture angulation (p < 0.001). Fracture location in the middle third, stable fracture pattern, method of treatment (i.e., antegrade or retrograde), and nail diameter were not associated with increasing fracture angulation (p > 0.05). The incidence of malalignment was 9 percent for the entire group of patients, 30 percent when the fracture was of the proximal third of the femoral shaft, 2 percent when the fracture was of the middle third, and 10 percent when the fracture was of the distal third. The incidence of malreduction was 7 percent for patients with stable fracture patterns and 12 percent for those with unstable fracture patterns.


CONCLUSIONS
Patients with fractures of the proximal third of the femoral shaft treated with intramedullary nails are at highest risk for malalignment. Proximal fracture location, distal fracture location, and unstable fracture pattern are associated with increasing fracture angulation.
Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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Ricci
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Bellabarba
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R
Lewis
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Evanoff
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Herscovici
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Dipasquale
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Sanders
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D017760:Bone Malalignment / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D001858:Bone Nails; D002648:Child; D005260:Female; D005264:Femoral Fractures / Q000175:diagnosis / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution