Background: The goal of treatment of a valgus
deformity of the knee that is secondary to osteoarthritis of the
lateral compartment is to obtain axial correction of the malalignment
of the extremity. Osteosynthesis of the osteotomized femur with
use of internal fixation and a stiff implant has not been as successful as
expected. We evaluated the accuracy and maintenance of correction
and the stability of fixation with a malleable plate after a supracondylar
osteotomy of the distal aspect of the femur that was performed to
correct a valgus deformity of the knee.
Methods: We performed an incomplete oblique
osteotomy of the distal aspect of the femur in nineteen patients
(twenty-one knees) and stabilized the osteotomy site with a malleable
semitubular plate, which was bent to form an angled plate, and lag-screws. Postoperatively,
the patients were immediately encouraged to walk, with partial weight-bearing
on the affected extremity. The mean age of the patients was fifty-seven
years (range, thirty-nine to seventy-one years), and the mean duration
of follow-up was five years (range, two to twelve years).
Results: In seventeen knees, the osteosynthesis
withstood the mechanical loading that occurred during the postoperative
functional rehabilitation program. Prolonged use of crutches or
immobilization, or both, was necessary after the operation in three knees.
The osteosynthesis failed in one knee. The loss of correction in
eighteen knees, after bone-healing, averaged 1.7 degrees (range,
0 to 4 degrees).
Conclusions: Our method of achieving osteosynthesis
is based on the concept that inherent endogenous stability mechanisms
can be mobilized by circumferentially compressing the two cortical
tubes with the cut ends congruently apposed to each other. We believe
that our technique provides an alternative to osteosynthesis with
use of a stiff implant such as a fixed-angle blade-plate device.