Keywords
osteoarthrosis - osteotomy - sports - tibia
Introduction
The number of young adults with knee osteoarthritis (OA) has been increasing; however,
their age and functional activity are incompatible with a total knee arthroplasty
(TKA).[1]
[2]
[3]
[4] Over 25% of people < 70 years old have knee OA, and this figure is expected to exponentially
increase in the future. Sports and recreational activities are very important for
these subjects and OA limits such practice.[5]
Unicompartmental OA (UCOA) mainly involves the medial femorotibial compartment in
varying degrees, according to the radiographic criteria defined by Ahlback. Predominant
symptoms are pain that worsens under load and a progressive angular deformity.
The different therapeutic methods for UCOA include high tibial osteotomy (HTO), which
is indicated for physiologically young patients (< 60 years old) with isolated medial
OA, preserved range of motion (ROM), no ligament instability, minimum patellofemoral
symptoms, and failed conservative treatment. Relative contraindications for HTO include
age > 65 years old, advanced OA, three-compartment OA, inflammatory arthritis, decreased
ROM (< 120°), smoking, obesity (body mass index [BMI] > 30), and contracture in flexion > 5°.[5]
There are three main types of HTO: with an opening wedge, with a subtraction wedge
and the cupuliform procedure. The opening wedge technique has several advantages over
the closing wedge method, such as greater precision and ease of correction in both
the coronal and sagittal planes; in addition, it does not require a fibular osteotomy
or an approach to the proximal tibiofibular joint (which protects the fibular nerve),
sparing the bone stock and facilitating a conversion to TKA. The disadvantages of
the opening wedge technique include the creation of a bone defect (which, depending
on its size, may need a bone graft), risk of pseudarthrosis, potential loss of correction
due to synthetic collapse, and a longer period of time in which load is not allowed;
moreover, this procedure requires greater attention to the tibial slope.[3]
[4]
[6]
[7]
[8]
The technique was introduced by Jackson et al.[9] in 1961, but it only became popular in 1965, when Coventry[10] promoted it for treating medial OA with varus deformity. Since then, there have
been countless advances in the technique, fixation, and selection of patients, leading
to reduced complications and better outcomes.[3]
[4]
[6]
[7]
[8]
High tibial osteotomy aims to decrease the load in the involved compartment and transfer
it to the healthy compartment, correcting the angular deformity and promoting symptomatic
improvement of the affected knee.[1]
[2]
[3]
[7]
[8]
Because of the excellent HTO survival rates[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19] and the potential TKA risks, such as loosening, material wear or periprosthetic
fractures in subjects practicing high impact activities,[20] HTO is recommended for young adults. Johnstone suggested that young patients submitted
to osteotomy may resume their work and sports activities. On the other hand, the rate
of return to sports in patients undergoing TKA is of only 20%.[5]
Even though the HTO technique is well-described, few studies analyze the level of
return to sports and the clinical outcome after the opening wedge procedure in young
adults with UCOA.[2]
[3]
[22]
The present study aims to evaluate the resuming of physical activities by young, active
patients who practiced some sport modality and underwent an HTO procedure using the
opening wedge technique. Subjects were assessed using the Lysholm and International
Knee Documentation Committee (IKDC) scores, visual analog scale for pain (VAS) and
a comparison between pre- and postoperative sports performance level.
Material and Methods
The present study was performed at the Sports Traumatology Center from July 2017 to
January 2018, under the approval of the institutional Research Ethics Committee
Sample Description
A total of 12 patients were assessed, including 2 women and 10 men, with a mean age
of 34.3 years old (range, 30 to 44 years old) and an average BMI of 28.8 kg/m2 (range, 24.4 to 33.7 kg/m2). Preoperative ROM ranged from 90° to 132° (mean value, 108.3°) and the mechanical
axis of the affected lower limb ranged from 6.4° in varus to 2° in valgus, with an
average value of 3.4 ± 2.2° in varus.
Six subjects were street runners (lengths ranging from 5 to 21 kilometers), four were
field soccer players, one was a handball player and one practiced mixed martial arts
(MMA).
Adult patients aged 20 to 55 years old, with OA grade II to III according to the Ahlback
criteria, BMI < 35, ROM > 90° and who were not practicing sports for at least 3 months
were included in the study.
The following patients were excluded: those with a history of surgery on the affected
knee; subjects with bicompartmental or tricompartmental arthrosis, varus deformity > 15°,
symptomatic ligament instability, diabetes, inflammatory arthritis, and smokers.
Description of the Procedures
All patients underwent a previous clinical treatment for at least 6 months before
surgery. All of them underwent an HTO procedure according to the wedge opening technique,
using a wedge plate Puddu,[23] and they were submitted to the same rehabilitation protocol.
Preoperative planning employed long panoramic radiographs, analyzing mechanical and
anatomical axes to calculate the size of the required wedge according to the noyes
and Dugdale method.[24]
[25]
High tibial osteotomy was performed following the concept, in which the load axis
of the lower limb is kept in a neutral position and an hypercorrection of ∼ 2° to
5° in valgus is performed; as such, the mechanical axis passes laterally to the center
of the knee joint, ideally between the middle and lateral portion of the lateral condyle
(62%), and slightly lateral to the lateral intercondylar eminence.[3]
[24]
Opening wedges of up to 15 mm were made. Up to 10 mm, a plate spacer was used alone;
between 10 and 15 mm, an autologous tricortical graft from the ipsilateral iliac crest
was added.
Load bearing was allowed only after radiographic consolidation of the fracture. All
subjects answered questionnaires before surgery and at 6 weeks, 3 months, 6 months,
and 12 months postoperatively. The IKDC and Lysholm scores assessed the return to
sports, daily activities, clinical parameters, and personal satisfaction from each
patient. In addition, VAS was analyzed before surgery and 6 months after the procedure.
Using long panoramic anteroposterior radiographs, the anatomical axis (femorotibial
axis) and the mechanical axis of the lower limb were recorded pre- and postoperatively,
as well as the arthrosis degree according to the Ahlback criteria.
Patients were asked about their performance level when resuming sports, with the following
answers: they did not return to sports; they returned at a significant lower level
in comparison with the preoperative period; they returned at a slightly lower level
compared with the preoperative period; they returned at the same level compared with
the preoperative period; and they returned at a higher level in comparison with the
preoperative period.
Statistical analysis used the Spearman correlation coefficient to measure the degree
of relationship between all quantitative variables at all times: ROM, anatomical axis,
VAS, healing time, Lysholm score, IKDC score and BMI.
The Mann-Whitney test compared the degree of arthrosis for some quantitative variables:
preoperative anatomical axis, VAS gain, Lysholm score, IKDC score, and healing time.
Results were expressed as mean and standard deviation (SD).
Results
Radiographic healing time ranged from 7 to 11 weeks (mean, 9.16 weeks). This value
was correlated with the symptoms of the patients and the time in which partial progressive
load bearing was allowed.
The mean Lysholm score was 83.8 ± 8.2 points, ranging from 70 to 94 points (p < 0.05). In this evaluation, 7 patients (58.33%) had good results and 5 subjects
(41.66%) presented regular results.
After standardization in percentage, the average IKDC questionnaire score was 75.8 ± 9.8,
with values ranging from 62 to 84% (p < 0.05).
One patient presented delayed healing, requiring a new procedure to place an autologous
graft 6 months after the index surgery. This patient progressed satisfactorily 1 year
after the first procedure.
One patient resumed sporting activities at a performance level significantly lower
compared with the preoperative level, while eight patients returned at a slightly
below level, two returned at the same level and one patient returned at a higher level
in comparison with the preoperative period.
Both ROM and VAS presented significant statistical differences between pre- and postoperative
values. The mean VAS decreased from 6.83 to 3.53, whereas the mean ROM increased from
108.33° to 123.92° (p < 0.001) ([Table 1]).
Table 1
|
Finding
|
Mean
|
Median
|
Standard Deviation
|
Q1
|
Q3
|
n
|
CI
|
p value
|
|
Range of motion
|
Pre-
|
108.33
|
105.0
|
12.64
|
101.5
|
115.0
|
12
|
7.15
|
<0.001
|
|
Post-
|
123.92
|
124.0
|
7.49
|
119.5
|
130.0
|
12
|
4.24
|
|
Anatomical axis
|
Pre-
|
−3.32
|
−3.9
|
2.75
|
−5.4
|
−2.0
|
12
|
1.56
|
<0.001
|
|
Post-
|
6.38
|
6.5
|
1.89
|
4.8
|
8.0
|
12
|
1.07
|
|
Visual analog scale for pain
|
Pre-
|
6.83
|
6.4
|
1.12
|
6.0
|
7.9
|
12
|
0.64
|
<0.001
|
|
Post-
|
3.53
|
3.4
|
0.77
|
3.1
|
4.1
|
12
|
0.44
|
The Spearman correlation assessed the degree of relationship between all quantitative
variables at all times. A correlation test validated these findings, which were expressed
as a percentage. In this scale, values between 0 and 20% indicate a bad correlation;
from 20 to 40%, a very bad correlation; from 40 to 60%, a regular correlation; from
60 to 80%, a good correlation; and from 80 to 100%, an excellent correlation.
This analysis ([Table 2]) showed some statistically significant correlations: between the preoperative anatomical
axis and the Lysholm score of + 65.4%, indicating that the greater the preoperative
deformity, the better the subjective Lysholm score; between the preoperative anatomical
axis and a VAS score gain of + 48.5%; between the preoperative anatomical axis and
an IKDC score of + 48.5%. In addition, there was an inversely proportional correlation
between the preoperative anatomical axis and ROM gain value of 42.4%, indicating that
the greater the preoperative deformity, the lower the ROM gain (p < 0.001).
Table 2
|
|
Range of Motion
|
Anatomical Axis
|
Analog Visual Scale for Pain
|
Healing time
|
Lysholm Score
|
IKDC Score
|
|
|
Pre-
|
Post-
|
Gain
|
Pre-
|
Post-
|
Gain
|
Pre-
|
Post-
|
Gain
|
|
Range of motion
|
Post-
|
Corr
|
76.50%
|
|
|
p-value
|
0.004
|
|
|
Gain
|
Corr
|
−67.00%
|
−19.70%
|
|
|
p-value
|
0.017
|
0.539
|
|
|
Pre-
|
Corr
|
57.90%
|
58.00%
|
−42.40%
|
|
|
p-value
|
0.049
|
0.048
|
0.169
|
|
|
Anatomical axis
|
Post-
|
Corr
|
21.40%
|
11.30%
|
−8.70%
|
35%
|
|
|
p-value
|
0.503
|
0.727
|
0.789
|
0.264
|
|
|
Gain
|
Corr
|
−56.10%
|
−74.50%
|
32.70%
|
−87.90%
|
−4.60%
|
|
|
p-value
|
0.058
|
0.005
|
0.299
|
<0.001
|
0.888
|
|
|
Pre-
|
Corr
|
7.80%
|
−3.40%
|
−19.80%
|
−32.50%
|
4.40%
|
21.20%
|
|
|
p
|
0.810
|
0.917
|
0.538
|
0.303
|
0.892
|
0.506
|
|
|
Visual analog scale for pain
|
Post-
|
Corr
|
7.20%
|
−7.80%
|
−20.90%
|
3.20%
|
−43.80%
|
−1.20%
|
17.20%
|
|
|
p-value
|
0.824
|
0.811
|
0.514
|
0.922
|
0.155
|
0.97
|
0.594
|
|
|
Gain
|
Corr
|
0.90%
|
−6.10%
|
−5.30%
|
48.50%
|
−3.90%
|
−27.50%
|
−87.90%
|
15.70%
|
|
|
p-value
|
0.978
|
0.874
|
0.869
|
0.110
|
0.905
|
0.388
|
< 0.001
|
0.626
|
|
|
Healing time
|
Corr
|
50.80%
|
61.20%
|
−37.60%
|
34.40%
|
−47.50%
|
−58.30%
|
−19.90%
|
24.60%
|
19.60%
|
|
|
p-value
|
0.092
|
0.035
|
0.228
|
0.274
|
0.119
|
0.047
|
0.536
|
0.441
|
0.541
|
|
|
Lysholm score
|
Corr
|
64.60%
|
52.80%
|
−52.90%
|
65.40%
|
11.10%
|
−67.40%
|
9.80%
|
33.70%
|
9.00%
|
30.80%
|
|
|
p-value
|
0.023
|
0.077
|
0.021
|
0.731
|
0.016
|
0.763
|
0.284
|
0.781
|
0.331
|
|
|
IKDC score
|
Corr
|
60.80%
|
53.40%
|
−23.80%
|
43.90%
|
45.60%
|
−36.40%
|
44.90%
|
−3.70%
|
−32.00%
|
−6.50%
|
54.90%
|
|
|
p-value
|
0.036
|
0.074
|
0.456
|
0.153
|
0.136
|
0.244
|
0.144
|
0.909
|
0.311
|
0.842
|
0.064
|
|
|
Body mass index
|
Corr
|
−39.20%
|
−45.20%
|
−12.00%
|
−52.20%
|
−51.90%
|
34.60%
|
7.10%
|
14.20%
|
−5.10%
|
12.70%
|
−12.00%
|
−68.80%
|
|
p-value
|
0.208
|
0.140
|
0.709
|
0.082
|
0.084
|
0.271
|
0.827
|
0.659
|
0.875
|
0.693
|
0.711
|
0.044
|
Other correlations that deserve being highlighted were between BMI and an IKDC score
of - 58.8% and between preoperative ROM and an IKDC score of + 60.8.
The Mann-Whitney test concluded that there was no statistically significant difference
between the degrees of arthrosis for the variables analyzed: preoperative anatomical
axis, VAS gain, Lysholm score, IKDC score and healing time ([Table 3]).
Table 3
|
Arthrosis Grade (Ahlback)
|
Mean
|
Median
|
Standard Deviation
|
Q1
|
Q3
|
n
|
CI
|
p-value
|
|
Preoperative anatomical axis
|
Grade II
|
−2.80
|
−2.2
|
3.55
|
−6.2
|
−1.2
|
5
|
3.11
|
0.808
|
|
Grade III
|
−3.69
|
−4.2
|
2.25
|
−4.8
|
−3.5
|
7
|
1.67
|
|
Pain gain
|
Grade II
|
−3.48
|
−4.0
|
0.98
|
−4.0
|
−3.0
|
5
|
0.86
|
0.935
|
|
Grade III
|
−3.17
|
−3.2
|
1.34
|
−4.2
|
−2.5
|
7
|
0.99
|
|
Lysholm score
|
Grade II
|
82.00
|
82.0
|
9.27
|
76.0
|
90.0
|
5
|
8.13
|
0.624
|
|
Grade III
|
85.14
|
88.0
|
8.07
|
80.0
|
90.0
|
7
|
5.98
|
|
IKDC score
|
Grade II
|
78.40
|
80.0
|
5.18
|
74.0
|
82.0
|
5
|
4.54
|
0.414
|
|
Grade III
|
74.00
|
76.0
|
8.16
|
69.0
|
79.0
|
7
|
6.05
|
|
Healing time
|
Grade II
|
9.40
|
10.0
|
1.34
|
8.0
|
10.0
|
5
|
1.18
|
0.618
|
|
Grade III
|
9.00
|
9.0
|
1.29
|
8.5
|
9.5
|
7
|
0.96
|
Discussion
There are several questions about outcomes and the effective ability of patients undergoing
HTO to resume sporting, daily living and recreational activities with no limitations
or pain.
The literature reports excellent to good outcomes from HTO with an opening wedge for
UCOA and poor alignment treatment: Hernigou et al.[13] described 81% of excellent or good results after 10 years of follow-up with 53 patients.
Aglietti et al.[26] performed a clinical follow-up of 61 patients for up to 21 years after HTO and observed
that 79% of them had no pain or presented mild pain in the operated knee.
Regarding post-HTO sports practice, some previous studies have shown good outcomes
and high rates of return. Salzmann et al.[22] noted that 90.9% of patients were participating in sports and recreational activities,
compared with 87.9% before surgery. The Lysholm score and VAS increased significantly,
from 42.4 to 69.6 and from 6.9 to 2.9, respectively (p < 0.01).
Faschingbauer et al.[21] analyzed the rate of return to work and sports in 51 patients submitted to HTO.
According to these authors, 92.3% of the patients returned to sports in similar performance
levels compared with the preoperative period; in addition, they observed a shift from
high impact to low impact activities, and they noticed a decrease in the duration
and amount of sports activity.
Hoorntje et al.[27] conducted a systematic review on this subject, which revealed an 82% rate of return
to sport in studies with sound methodology and low risk of bias (totaling 11 studies).
They also reported a survival rate of 87 to 99% at 5 years and of 66 to 84% at 10
years after HTO. The studies differed considerably in terms of sports activity assessment
(level of practice).
In another systematic review, Ekhtiari et al.[28] analyze the return to work and sports activities after HTO. This review included
11 studies, totaling 250 patients with a mean age of 46.2 years old. The opening wedge
was the most used technique. After the procedure, 87.2% of the patients returned to
sports, with 78.6% resuming their activities in equal or higher levels. Among competitive
athletes, 54% returned to competitions. Approximately 90% of the patients who returned
to work and sports activities did so within 1 year. In addition, 7% underwent TKA
after an average period of 6.7 years. Several methods were used to measure the level
of physical activity.
Bastard et al.[29] retrospectively analyzed 30 patients for a mean follow-up period of 1.3 years and
observed that all subjects returned to sports within 1 year, including 73.3% at the
same preoperative performance level and 23.3% at higher levels.
W-Dahl et al.[30] followed-up 79 HTO patients for 10 years. After this period, 25 subjects underwent
TKA. These authors concluded that HTO is an excellent solution for young patients
with OA who present moderate degeneration over time, providing the possibility of
physical activity and quality of life. Two years after HTO, patients increased their
physical activity, and more than half of them participated in sports such as golf,
dance, walking and water aerobics. After 10 years, almost half were still involved
in the same activities.
Our study corroborates these findings and demonstrates that opening wedge HTO has
good functional outcomes. The anatomical axis was satisfactorily corrected from 3.31 ± 1.2°
in varus for an average value of 6.38 ± 1.8 degrees in valgus. One patient did not
present overcorrection, with an alignment to 3.6 degrees in valgus. This patient had
the worst functional outcomes, with a Lysholm score of 70 and an IKDC score of 62%.
The importance of proper preoperative planning, anatomical and mechanical axis calculation
and wedge size determination must be highlighted, since these factors will have a
direct impact on the outcome.
In a specific analysis, the Lysholm and IKDC scores were significant, with 7 patients
(58.33%) presenting a good Lysholm score and a mean percentual IKDC 75.8 ± 9.8 (p < 0.05) at an 84% index.
There was a significant improvement in ROM gain and VAS. The present study reinforces
the use of HTO with an opening wedge with good outcomes and potentially resuming activities
in levels which are close to the preoperative ones.
The present study has some limitations: small sample; lack of control group; short
follow-up time, possibly interfering with the level of return to sports; and lack
of training periodicity, intensity, and volume assessment. These are preliminary findings
and we plan to add more patients to our research for further evaluation to achieve
more significant statistical results.
Conclusion
Open wedge HTO as treatment for isolated medial osteoarthrosis demonstrates favorable
clinical and functional outcomes, allowing the patient to resume sports activities.
