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Surgery was performed in supine position
under general anesthesia and fluoroscopic
control with the knee flexed at 90°. Arthroscopy
was systematically performed at the beginning
of the procedure to assess of cartilage status of
the three compartments but also to treat a
possible meniscal flap.
The approach was classically anteromedial,
starting at the apex of the patella. Hamstring
tendons were realeased from their tibial
insertion and retractor was placed behind the
posterior aspect of the tibia to protect the
neurovascular structures. Two parallel K-Wires
were introduced from the medial aspect of the
tibia to the upper part of the proximal
tibiofibular joint (fig. 1A). The superficial layer
of the medial collateral ligament was cut and
the osteotomy was performed just below the
K-Wire (fig. 1B). A second cut was driven few
millimeters over the first one (fig. 1C). A lateral
hinge should be preserved. Then the K-Wires
were removed and a triangular bone wedge was
resected (fig. 1D). Primary resection should be
as economic as possible to avoid overcorrection.
Applying a varus stress on the tibia, the
osteotomy was closed. The osteotomy was
temporary fixed with a staple (fig. 1E) and the
correction was analyzed under fluoroscopy
with a rod joining the center of the hip to the
center of the ankle (fig. 1F). A normal
mechanical axis was aimed. At this step, no
varus stress should be applied to avoid lateral
collateral ligament tensioning and pseudo-
overcorrection (fig. 1G). If the correction was
insufficient, an additional bone wedge was
removed. When the final correction was
reached, the staple was removed and the
osteotomy was fixed with a four-hole C-plate
or T-plate (fig. 1H).
Postoperatively, the lower limb was
immobilized in a functional brace and early
rehabilitation was allowed. Patients were non-
weight bearing for 45 days then progressive
weight bearing during the next two weeks.
Outcome measures
Themain purpose of this studywas survivorship
analysis. In a best case scenario, the end-point
was the failure of the osteotomy leading to total
knee arthroplasty. In a worst case scenario, the
end-point was the date of the knee replacement
procedure, or the last review for the unsatisfied
patients or the ones lost to follow-up.
Clinical outcomeswere analyzedpreoperatively
and at final follow-up using the Knee Society
Score [9]. Activity level using the UCLA score
[10] was recorded 3 times: before the symptoms,
before the osteotomy, and at the final follow-
up. Knee injury and Osteoarthritis Outcome
Score (KOOS) was used only for final self-
assessment [11]. Complications and subsequent
knee surgeries were also recorded since the
index procedure.
Radiographic analysis included measurement
of the mechanical Medial Proximal Tibial
Angle (MPTA), the mechanical Lateral Distal
Femoral Angle (mLDFA), the Joint Line
Convergent Angle (JLCA), using Paley’s
method, and the Hip-Knee-Ankle angle (HKA:
mechanical tibiofemoral angle) on standardized
long-leg standing weight-bearing view [12].
Tibial slope and Caton-Deschamps index were
measured on lateral view [13]. Tibiofemoral
andpatellofemoral osteoarthritiswere evaluated
according to Ahlbäck and Iwano classifications
preoperatively and at final follow-up [8, 14].
Statistical analysis
Statistical significance was set at p<0.05.
Cumulative survival rate was estimated by
Kaplan-Meier analysis. Normally from non-
normally distributed data were distinguished
by Shapiro-Wilk test. In the first case, after
variance equality test, paired Student’s
t
-test
was used to find a statistical significant change