108 / 242
N. Jan, P. Chambat, J.-M. Fayard
108
In 2 patients, joint line obliquity of more than
10° was recorded. One patient had clinical
improvement (function score +10; knee score
+29) at 3.6 years follow-up. No tibiofemoral
instability was recorded. The second patient
presented recurrent pain with tibiofemoral
instabilty one year after the index procedure.
He underwent knee replacement at 4.4 years
follow-up.
Prognostic factors
Using independent T test, the mean time
between lateral meniscectomy and the
osteotomy seemed to be significantly different
(p<0,001) between the failure group (8.5 years)
and success group (24.9 years) as defined in the
worst case scenario.
No significant difference was found between
the failure group and success group for MPTA
and mLDFA. But 2 early failures occurred in
patient with a femur valga and there was a
greater proportion of femur valga (mLDFA
< 85°) than tibia valga (MPTA>90°) in the
failure group.
Discussion
There is low evidence in literature about varus
osteotomies for valgus arthritic knees and most
of the studies concern distal femoral varus
osteotomies (DFVO) [15]. Allthough these
series were heterogeneous in term of surgical
technique, clinical assessment and follow-up,
all of them reported good results with significant
improvement of the clinical and functional
scores. But functional outcomes and survival
rate tend to decrease after ten years follow-up.
Our long term study showed a significant
improvement of IKS knee and function scores
but also of the UCLA activity score at a mean
10 years follow-up after closing wedge
HTVO.
Concerning survivorship of DFVO, revision
rate by knee arthroplasty ranged between 10
and 37% at 10 years follow-up [16, 17]. In the
present study of HTVO, we reported a revision
rate of 13% at 10 years follow-up.
If lateral unicondylar arthroplasty seems to be a
possible option with good long-term functional
outcomes, younger patients are more exposed
to early failure. A recent study of the National
Joint Registry reported 5% revision rate at five
years follow-up. This revision rate increased
over 10% for patients under 50 years old [18].
By sparing bone stock and allowing good long-
term functional results, osteotomy is a suitable
option for young and/or active patient suffering
from lateral knee osteoarthritis.
However, several authors reported a high rate
of complications and subsequent surgeries after
antivalgus osteotomies. In the earliest reports
of closing wedge HTVO, instability, loss of
correction, early degeneration of the medial
compartment and poor results were reported.
Table 3 : Radiographic assessment of osteoarthritis
Preoperative
Final follow-up
Sign test
Median
Range
Median
Range
p
Ahlbäck classification
Lateral tibiofemoral
2
1-3
3
2-4
0,387
Medial tibiofemoral
0
0-1
0
0-2
0,63
Iwano Cassification
Femoropatellar
1
0-3
1
0-3
0,113