Background: The results of hemiepiphysiodesis for the treatment of
late-onset tibia vara have been reported to be favorable, but the technique
requires careful timing and an accurate estimation of skeletal age.
Hemiepiphyseal stapling does not require a careful estimation of skeletal age,
and it has been reported to yield good results with low morbidity. However, we
are not aware of any study evaluating the intermediate-term radiographic
results or complications of this procedure.
Methods: Twenty-six patients with thirty-three extremities with
late-onset tibia vara were treated with proximal tibial hemiepiphyseal
stapling. Fourteen extremities had substantial concomitant distal femoral
varus and also had hemiepiphyseal stapling of the distal part of the femur.
Eighteen patients (twenty-three involved extremities) had juvenileonset tibia
vara and eight patients (ten involved extremities) had adolescent-onset tibia
vara. The mean age at the time of stapling was 11.8 years. The mean duration
of follow-up was 3.8 years. We reviewed standardized standing radiographs to
determine the mechanical axis deviation, the medial proximal tibial angle, the
lateral distal femoral angle, and the zone of the knee through which the
mechanical axis passed.
Results: The mean mechanical axis deviation improved from 58 mm
(range, 27 to 157 mm) preoperatively to 22 mm (range, -33 to 117 mm) at the
time of the last follow-up, and the mean medial proximal tibial angle improved
from 77° (range, 50° to 85°) to 85° (range, 48° to
95°). In the fourteen lower extremities in which distal femoral
hemiepiphyseal stapling was performed, the mean lateral distal femoral angle
improved from 96° (range, 92° to 100°) to 86° (range, 79°
to 97°). At the time of the final follow-up, seven extremities were
considered to be in moderate varus; four, in mild varus; twenty, in normal
alignment; and two, in valgus. No differences in radiographic outcome were
noted between the juvenile and adolescent forms of tibia vara. Only one of the
four extremities with severe preoperative varus was corrected to normal
alignment; the remaining three were left with moderate varus.
Conclusions: Hemiepiphyseal stapling of the lateral aspect of the
proximal tibial physis and, as needed, the lateral aspect of the distal
femoral physis is safe and effective in children with late-onset tibia vara if
the physes are sufficiently open and the varus deformity is mild to moderate.
Hemiepiphyseal stapling is particularly effective in patients who are ten
years of age or younger.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.