Extension malunion of the femoral component after retrograde nailing: no sequelae at 6 years.
OBJECTIVE
Supracondylar femoral fracture is a complex complication after total knee arthroplasty (TKA). One potential complication of retrograde locked nailing is malunion in extension of the femoral prosthetic component--produced by an overly posterior nail entry point in the intercondylar notch. The aim of this study was to determine the repercussion of this deformity on the midterm radiological and functional outcomes of TKA.


METHODS
Retrospective review.


METHODS
From 2001 to 2006, 30 patients were treated for supracondylar femoral fracture above TKA with a retrograde locked nail. In 7 patients (6 women and 1 man) with a mean age of 78.8 years (range, 74-84 years), more than 10 degrees of hyperextension (mean of 18.5 degrees) of the femoral component on the sagittal plane was observed without any significant misalignment on the coronal plane. Functional outcomes were assessed using the Knee Society Score.


RESULTS
After a mean follow-up of 68.5 months (range, 48-111 months), all patients' fractures with a hyperextension of the femoral component had consolidated with no clinical or radiological signs of TKA loosening. These patients presented "good" functional outcomes at final follow-up.


CONCLUSIONS
These results should be interpreted with caution. However, isolated hyperextension of the femoral component of a TKA after placing a retrograde nail for a periprosthetic fracture does not seem to significantly affect the functional or radiological outcomes at ∼6-years follow-up.


METHODS
Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Orthopaedic Department, Parc de Salut Mar, Passeig Marítim 25-29, 08003, Universitat Autònoma Barcelona, Barcelona-Spain.
Xavier
X
Pelfort
Raúl
R
Torres-Claramunt
Pedro
P
Hinarejos
Joan
J
Leal
Sergi
S
Gil-González
Lluís
L
Puig
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D005264:Femoral Fractures / Q000209:etiology / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary; D017759:Fractures, Malunited / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008297:Male; D057068:Periprosthetic Fractures / Q000209:etiology / Q000601:surgery*; D012189:Retrospective Studies