Varus Ankle Correction Article

FOOT & ANKLE INTERNATIONAL
Copyright ? 2009 by the American Orthopaedic Foot & Ankle Society
DOI: 10.3113/FAI.2009.05

 

Oblique Supramalleolar Opening Wedge Osteotomy Without Fibular Osteotomy
for Varus Deformity of the Ankle

Keun-Bae Lee, MD, PhD and Yong-Jin Cho, MD
Gwangju, South Korea
Level of Evidence: V, Expert Opinion

 

INTRODUCTION
Varus deformities of the ankle which occur intrinsically
or secondary to a malunited fracture of the distal tibial
epiphysis or of the distal third of the tibial shaft can cause
pain and decreased range of motion. They eventually result
in osteoarthrosis of the ankle and functional disability.5,6
To prevent progression to osteoarthrosis in varus deformed
ankle joints, supramalleolar opening wedge osteotomy of the
distal tibia with concurrent fibular osteotomy has often been
utilized because of the straightforward approach, it simplifies
bone cuts and deformity correction, and causes no resultant
leg length discrepancy.3,5,6
The authors developed a new oblique supramalleolar
opening wedge osteotomy without fibular osteotomy. The
osteotomy apex is placed in the distal tibiofibular joint to
minimize the adverse effects of mortise distortion and lateral
ankle joint impingement, and to enhance the stability of the
osteotomy site due to the presence of an intact fibula (Figure
1). This new osteotomy is easily performed, fast, stable,
reproducible, and safe for correcting varus deformed ankle
joints.
TECHNIQUE
The patient is placed in the supine position on the operating
table under general anesthesia. A thigh tourniquet is
No benefits in any form have been received or will be received from a commercial
party related directly or indirectly to the subject of this article.
Corresponding Author:
Keun-Bae Lee, MD, PhD
Department of Orthopedic Surgery
Chonnam National University Medical School and Hospital
8 Hakdong, Donggu
Gwangju, 501-757
South Korea
E-mail: kbleeos@chonnam.ac.kr
For information on pricings and availability of reprints, call 410-494-4994, x232.
then applied. After determining the level of the osteotomy
using an image intensifier, a skin incision is made on the
medial side of the distal tibia centered over the osteotomy
site. Minimal periosteal stripping is performed, only to an
extent required to complete the osteotomy. To guide the
osteotomy plane, a Kirschner wire is placed approximately
4 to 5 cm proximal to the tip of the medial malleolus and
inserted obliquely toward the distal tibiofibular joint. The
apex of the oblique supramalleolar osteotomy is placed in
the syndesmosis. The osteotomy is made using a broad oscillating
saw, to preserve the opposite cortex to act as a fulcrum
for the opening wedge and to enhance stability. The fibula
is left intact. Careful correction of the deformity is achieved
by the stepwise insertion of 2 or 3 osteotomes to avoid far
cortex fractures. Alignment is assessed using an image intensifier.
When the preoperatively planned correction has been
achieved, the length of the opening wedge base is measured
using a gap indicator, and the osteotomy is stabilized using a
single opening wedge plate (B. Braun Aesculap, Tuttlingen,
Germany). The osteotomy gap is filled with cancellous bone
allograft (Figure 2).
Postoperatively, patients are immobilized in a posterior
splint. After 1 week, sutures are removed and a nonweightbearing
short leg cast is applied for 4 weeks. The cast is then
changed to a removable boot and touch-down weightbearing
allowed. However, full weightbearing is not allowed until
there was evidence of radiographic healing.
DISCUSSION
In cases of torsional deformity in childhood, there is some
debate as to whether concurrent fibular osteotomy should
be performed during supramalleolar osteotomy. Bennett
et al.2 recommended concurrent fibular osteotomy to attain
full derotation and to avoid changing the mechanics of
the ankle joint when rotational osteotomy of the distal
tibia is performed. Furthermore, they demonstrated that
the medial malleolus would be rotated against a fixed
lateral malleolus if fibular transection is not performed.
565
566 LEE AND CHO Foot & Ankle International/Vol. 30, No. 6/June 2009
A B
Fig. 1: Preoperative (A) anteroposterior radiograph of a severe varus malunion of a distal tibial fracture, showing the center of rotation and angulation (CORA)
and the tibial-ankle surface (TAS) angle. After a medial opening wedge osteotomy, the TAS substantially improved (B).
A B C
D E
F
Fig. 2: Fluoroscopy was used to confirm the level of the osteotomy (A), and an oblique osteotomy was made using a broad oscillating saw (B). Planned
correction was achieved by carefully widening with two osteotomes under image intensification (C). The gap was measured using a gap indicator (D). The
osteotomy was fixed using an opening wedge plate (E) and the space was filled with a cancellous allograft (F).
Foot & Ankle International/Vol. 30, No. 6/June 2009 OBLIQUE SUPRAMALLEOLAR OSTEOTOMY FOR VARUS ANKLE 567
Conversely, Banks et al.1 and Ryan et al.4 described a
technique that achieved full derotation without concurrent
fibular osteotomy. In addition, they found that an intact
fibula provides additional support for the osteotomized tibia,
and in particular, protects it from sagittal plane angulation.
Our osteotomy plane, which was placed at the apex of
the syndesmosis, minimized the adverse effect of mortise
distortion and enhanced osteotomy site stability due to the
presence of an intact fibula. In addition, the use of an opening
wedge plate obviates the need for structural, ie. tricortical
iliac autograft, because it is stabilized by the shape and
size of the plate wedge block and by the cancellous bone
allograft. Furthermore, soft tissue coverage can be achieved
easily with a low profile plate, which contains the screw
head. No complications have been attributed to the described
technique to date.
REFERENCES
1. Banks, SW; Evans, EA: Simple transverse osteotomy and threaded-pin
fixation for controlled correction of torsion deformities of the tibia. J.
Bone Joint Surg. 37-A:193 – 195, 1955.
2. Bennett, JT; Bunnell, WP; MacEwen, GD: Rotational osteotomy of
the distal tibia and fibula. J. Pediatr Orthop. 5:294 – 298, 1985.
3. Giannini, S; Buda, R; Faldini, C; et al.: The treatment of severe
posttraumatic arthritis of the ankle joint. J. Bone Joint Surg. 89-A Supp.
3:15 – 28, 2007. http://dx.doi.org/10.2106/JBJS.G.00544
4. Ryan, DD; Rethlefsen, SA; Skaggs, DL; Kay, RM: Results of
tibial rotational osteotomy without concomitant fibular osteotomy in
children with cerebral palsy. J. Pediatr Orthop. 25:84 – 88, 2005.
http://dx.doi.org/10.1097/00004694-200501000-00019
5. Stamatis, ED; Cooper, PS; Myerson, MS: Supramalleolar osteotomy
for the treatment of distal tibial angular deformities and arthritis of the
ankle joint. Foot Ankle Int. 24:754 – 764, 2003.
6. Takakura, Y; Takaoka, T; Tanaka, Y; Yajima, H; Tamai, S: Results
of opening-wedge osteotomy for the treatment of a post-traumatic varus
deformity of the ankle. J. Bone Joint Surg. 80-A:213 – 218, 1998