n Feature Article

Medial Compartment Decompression

by Fibular Osteotomy to Treat Medial
Compartment Knee Osteoarthritis:
A Pilot Study
Zong-You Yang, MD; Wei Chen, MD; Cun-Xiang Li, MD; Juan Wang, MD; De-Cheng Shao, MD;
Zhi-Yong Hou, MD; Shi-Jun Gao, MD; Fei Wang, MD; Ji-Dong Li, MD; Jian-Dong Hao, MD;
Bai-Cheng Chen, MD; Ying-Ze Zhang, MD

abstract

Compared with high tibial osteotomy and total knee arthroplasty, the authors found
a simpler surgical procedure, partial fibular osteotomy, could effectively relieve knee
pain and also correct the varus deformity for patients with medial compartment knee
osteoarthritis (OA). From January 1996 to April 2012, a total of 156 patients with
medial compartment OA were treated by proximal fibular osteotomy in the authors’
hospital. A 2-cm–long section of fibula was resected 6 to 10 cm below the fibu-
lar head. A total of 110 patients with follow-up of more than 2 years were included
in the study, including 34 males and 76 females with an average age of 59.2 years.
Anteroposterior and lateral weight-bearing radiographs, the femorotibial angle (FTA) and
lateral joint space, and the American Knee Society Score (KSS) and the visual analog
scale (VAS) score of the knee joint were evaluated preoperatively and at final follow-
up, respectively. At final follow-up, mean FTA and lateral joint space were 179.4°±1.8°
and 6.9±0.7 mm, respectively, which were significantly smaller than those measured
preoperatively (182.7°±2.0° and 12.2±1.1 mm, respectively; both P<.001). Mean KSS at
final follow-up was 92.3±31.7, significantly higher than the mean preoperative score of
45.0±21.3 (P<.001). Mean VAS score and interquartile range were 2.0 and 2.0, signifi-
cantly lower than the preoperative data (7 and 1.0, respectively; P<.001). The authors
found that proximal fibular osteotomy can significantly improve both the radiographic
appearance and function of the affected knee joint and also achieve long-term pain re-
lief. This procedure may be an alternative treatment option for medial compartment OA.
[Orthopedics. 2015; 38(12):e1110-e1114.]

The authors are from the Department of Orthopedic Surgery, Third Hospital of Hebei Medical Uni-
versity, the Orthopaedic Research Institution of Hebei Province, and Key Laboratory of Orthopedic
Biomechanics of Hebei Province, Hebei (Z-YY, WC, JW, D-CS, Z-YH, S-JG, FW, J-DH, B-CC, Y-ZZ);
the Department of Orthopedic Surgery (C-XL), the People’s Hospital of Ningjin County; and the De-
partment of Orthopedic Surgery (J-DL), the People’s Hospital of Jingxing County, People’s Republic
of China.
The authors have no relevant financial relationships to disclose.
Drs Yang and W. Chen contributed equally to this work and should be considered as equal first authors.
Correspondence should be addressed to: Ying-Ze Zhang, MD, Department of Orthopedic Surgery,
Third Hospital of Hebei Medical University, No 139 ZiQiang Rd, Shijiazhuang, Hebei 050051, People’s
Republic of China (dryzzhang@126.com).
Received: May 21, 2015; Accepted: October 16, 2015.
doi: 10.3928/01477447-20151120-08

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 n Feature Article

NOTE: Fibular osteotomy represents a

unique way to treat knee osteoarthritis
that cannot be fully explained by biome-
chanical studies to date. I have person-
ally seen this procedure, examined pa-
tients both before and after surgery, and
watched patients walk just hours after the
surgery. The short-term outcomes I wit- A B
nessed, along with the mid-term results Figure 1: Preoperative anteroposterior (A) and A B
being published from this institution, can- lateral (B) radiographs of a 64-year-old woman Figure 2: Diagrams of the femorotibial angle and
not be ignored. However, I do think this showing a severe degree of medial compartment lateral knee joint space measurement. Line OA is
osteoarthritis and knee varus deformity. the femoral shaft anatomical axis; line OB is the
necessitates additional clinical trials in
other countries to further validate the tibial shaft anatomical axis; and angle a is the fem-
orotibial angle (A). Line CD runs through the tops
results. This pilot study provides a sound can correct lower extremity alignment, of the medial and lateral condyles of the tibia; point
framework for further research.—Craig relieve pain, and improve function sig- E is the outer one-sixth point of line CE; and line
Hogan, MD, University of Colorado Hos- nificantly. However, for younger, active EF is perpendicular to line CD and stands for the
pital, reviewer patients or patients with moderate OA, it distance of the lateral knee joint space (B).
may not be the treatment of choice.8

K
nee osteoarthritis (OA) is a Based on previous image and clinical had an indication for a surgical proce-
chronic, progressive degen- studies, the authors believe that the lateral dure, and who were able to give informed
erative disease with accom- support provided to the osteoporotic tibia consent for the surgery (Figure 1). Ex-
panying joint pain, stiffness, and de- by the fibula–soft tissue complex may lead clusion criteria included patients with
formity.1 Knee OA is a common joint to the nonuniform settlement and degener- posttraumatic knee OA or inflammatory
disease, with an incidence of 30% of ation of the plateau bilaterally.9,10 This may joint disease and patients with a history
the population older than 60 years.2 result in the load from the normal distribu- of previous operations or fractures. Pa-
The initiation and progression of knee tion shifting farther medially to the medial tients in whom conservative management
OA involves mechanical, structural, ge- plateau and consequently lead to knee var- has failed and who have radiographic
netic, and environmental factors.3 Knee us, aggravating the progression of medial evidence of significant varus are good
varus deformities, characterized by a compartment OA of the knee joint. Using candidates for partial fibular osteotomy.11
mechanical femorotibial axis of less this logic, the authors have performed a Between January 1996 and April 2012,
than 180° on full-leg standing antero- proximal fibular osteotomy to relieve the a total of 156 patients with medial com-
posterior (AP) radiographs and narrowed increased loading force on the medial com- partment OA were candidates to receive
medial joint space, are common in pa- partment for treatment of medial compart- fibular osteotomy. Forty-six patients were
tients with knee OA and affect 74% of ment OA of the knee joint. The goal of excluded for the following reasons: lost
patients with idiopathic OA.4 Although this retrospective study was to evaluate the to follow-up (n=21), fear of adverse ef-
it has been reported that even in healthy radiographic and clinical outcomes of pa- fects from the procedure (n=10), and
knees the medial compartment bears tients with medial compartment OA treated nonprocedure-related reasons (n=15).
60% to 80% of the load,5 no one has by partial fibular osteotomy with a mean
precisely documented what contributes follow-up of 49.1 months. Outcome Measures
to this uneven load distribution. The cur- The primary outcome measure was the
rent belief is that the load is distributed Materials and Methods difference in femorotibial angle pre- vs
along the mechanical axis, which is gen- Institutional review board approval postoperatively, with a minimum 2-year
erally medial to the center of the knee. was obtained for this study (No. Ke2014- follow-up. The degree of correction was
High tibial osteotomy and total knee 004-1). All patients agreed to participate an important factor in patient outcome
arthroplasty are the 2 methods used for in this study and gave informed consent. and gave an objective measurement. The
treating knee OA. High tibial osteotomy method of measurement was that of Wang
can be a technically demanding procedure Study Population et al12 (Figure 2), in which the angle a
and may result in complications, including Inclusion criteria included patients stood for the femorotibial angle (FTA)
neurovascular injury, iatrogenic fracture, with moderate to severe symptomatic me- and the line EF stood for the lateral joint
and nonunion.6,7 Total knee arthroplasty dial compartment OA of the knee, who space of the knee joint.

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n Feature Article

sealed with bone wax. The muscles, fas- ported limited range of knee motion, varus
cia, and skin were sutured separately after deformity, and severe knee pain, especially
the incision had been irrigated with a large after increased weight bearing or athletic
volume of normal saline. Postoperatively, activities. Preoperative AP radiographs of
the patients were ambulated as soon as the affected knees revealed narrow joint
pain could be tolerated. space in the medial compartments and
sclerosis around the femorotibial joints
A B Follow-up (Figure 1). The patients had experienced
Figure 3: Anteroposterior (A) and lateral (B) ra- Patients were followed up by 3 of the OA for a range of 19 to 82 months. After
diographs obtained immediately postoperatively authors (C.-X.L., B.-C.C., Y.-Z.Z.) at 1, partial fibular osteotomy was performed, 4
showing the recovered medial joint space and a 3, 6, and 12 months postoperatively and patients reported numbness in the ipsilater-
fibular defect. then annually thereafter. Weight-bearing al lower leg, including 2 common peroneal
AP and lateral radiographs of the affected nerve palsies and 2 superficial peroneal
The secondary outcome measure was knee were taken at each follow-up (Fig- nerve injuries, all of which resolved within
pain measured by the visual analog scale ure 3). 3 to 10 months. The fibular osteotomy was
(VAS).13 Data regarding age, sex, later- performed at the level of the femoral neck
ality, severity of OA, radiographic FTA Statistical Analyses in 3 of these patients and 6 to 10 cm be-
and lateral joint space, and preoperative Statistical analyses were performed us- low the fibular head in 1 patient. Sixteen
American Knee Society Score (KSS)14 ing SPSS version 19.0 statistical software patients reported weakness in the lower
were recorded for all patients at baseline for Windows (IBM, Armonk, New York). legs, and all returned to normal strength by
and at each follow-up visit. Continuous variables were expressed as 4 weeks. There were no superficial or deep
mean±SD and dichotomous variables infections. Four patients subsequently un-
Surgical Technique were expressed as percentages. Two-tailed derwent total knee arthroplasty at a mean
Under epidural anesthesia, the patients t test was applied to analyze the FTA and of 12.4 months (range, 7-17 months) after
were placed in the supine position with lateral joint space data. The nonparamet- the osteotomy due to residual pain and un-
the lower limb tourniquet inflated. First, ric test (Wilcoxon’s signed rank test) was satisfactory knee function.
the fibular head was marked. To avoid in- applied to analyze the VAS and KSS data. At final follow-up, 110 patients with
jury to the common fibular nerve and tibi- A P value less than .05 was considered to an average age of 63.5 years (range, 50-
al attachments of the soft tissue structures be significant. 73 years) were evaluated clinically and
crossing the knee joint, a lateral incision radiographically. On postoperative AP
of 3 to 5 cm was made at the proximal Results radiographs, bone defects of the proximal
third of the fibula. The fascia was then A total of 110 patients, including 34 fibula were observed in all patients. Ra-
incised in line with the septum between males and 76 females (62 right knees and diographic measurements obtained preop-
the peroneus and soleus, the muscles were 48 left knees), were available for a mean eratively and at final follow-up are listed
separated, and the fibula was exposed. A follow-up of 49.1 months (range, 24-189 in Table 1. At final follow-up, mean FTA
2-cm section of the fibula was removed months) and were included in this study. and lateral joint space were 179.4°±1.8°
6 to 10 cm below the fibular head with These patients had an average age of 59.2 and 6.9±0.7 mm, respectively, which were
the use of an oscillating saw or fret saw. years (range, 47-69 years) at the time of significantly lower than the data measured
Following resection, the fibula ends were surgery. Preoperatively, all patients re- preoperatively (P<.001). The lateral joint
space was narrower and the medial joint
space was wider than demonstrated on
preoperative radiographs. Mean KSS at
Table 1
final follow-up was 92.3±31.7, which
Preoperative and Final Follow-up Radiological Measurement was significantly larger than the preopera-
Values tive score (45.0±21.3; P<.001; Figure 4).
Mean±SD Mean VAS score and interquartile range at
Measurement Preoperative Final Follow-up t P final follow-up were 2.0 and 2.0, respec-
Femorotibial angle 182.7°±2.0° 179.4°±1.8° 12.863 <.001 tively, which were significantly lower than
Lateral joint space, mm 12.2±1.1 6.9±0.7 42.633 <.001 the preoperative data (7 and 1.0, respec-
tively; P<.001; Table 2).

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 n Feature Article

Discussion
High tibial osteotomy is a commonly Table 2
used method to treat knee varus defor-
Preoperative and Final
mities due to OA. It aims to improve the
Follow-up Visual Analog
mechanical axis passing from the center
of the hip, through the knee joint, to the Scale Scores
center of the tibiotalar joint in the coronal No. of Patients
plane.15,16 Osteotomies performed proxi- Final
VAS Score Preoperative Follow-up
mal to the tibial tubercle may interfere
0 0 16
with function of the patellar tendon.17-21
This patellofemoral disturbance is com- Figure 4: Pre- and postoperative American Knee 1 0 31
mon in patients who have previously un- Society (AKS) scores. The asterisk indicates a sig- 2 0 28
nificant difference between the 2 groups.
dergone proximal tibial osteotomies. In 3 0 35
the authors’ experience, a simple fibular 4 0 0
osteotomy can relieve knee pain and cor- Proximal osteotomy of the fibula weakens 5 0 0
rect varus deformity as effectively as high the lateral fibular support and leads to a 6 0 0
tibial osteotomy. correction of the varus deformity, which
7 62 0
Bone mass decreases as part of the can subsequently shift the loading force
8 31 0
normal aging process.22 Varying degrees from the medial compartment more lat-
9 17 0
of settlement of bone mass exist in the erally, leading to decreased pain and a
load-bearing joints, such as the knees, satisfactory functional recovery. Mean 10 0 0
hips, ankles, and spine. In the proximal KSS increased by 47.3 points in the final Z=-9.337
tibia, the lateral support of the fibula to analysis. According to VAS scores, pain P<.001
the lateral tibial plateau routinely leads levels decreased significantly from severe Abbreviation: VAS, visual analog scale.
to nonuniform settlement, which is more to mild.
severe in the medial plateau than in the Although proximal fibular osteotomy
lateral plateau. The slope of the tibial pla- is a simple procedure, care should be tak- ery of the knee joint. It may delay or even
teau arising from nonuniform settlement en to avoid potential peroneal nerve inju- negate the need for total knee arthroplasty.
results in a transverse shearing force, with ry. In this study, 4 (3.6%) patients reported It is a safe, simple, and effective proce-
the femoral condyle shifting medially numbness in the ipsilateral lower leg due dure that is an alternative to total knee ar-
during walking and sports.9 Furthermore, to common peroneal nerve palsy (n=2) throplasty for medial compartment OA of
side-slip aggravates the nonuniform set- and superficial peroneal nerve injury the knee joint. Care must be taken to avoid
tlement of the tibial plateau, especially in (n=2). Based on this anatomical study and potential nerve injuries.
the medial plateau. Accordingly, a cycle their own clinical experience, the authors
of increasing the load distribution in the recommend a posterolateral approach via References
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