INTRODUCTION:
Reconstruction of soft tissue defects in ankle and foot is
challenging because of more bony prominences and easy
exposure of tendons, nerves and vessels. Use of skin graft to
cover these sites is of not ideal choice because more morbidity
results due to cover of mobile structures thereby the function
is also impaired. Hence use of fasciocutaneous flaps to cover
these sites brings in a better vascularity to the site and thereby
provides a stable cover to the vital structures.
The lateral supramalleolar flaps have been used in the
past two decades as fasciocutaneous flaps for reconstruction of
ankle and foot defects. Even though free flaps are a option for
reconstruction of such defects, the expertise and facilities for
microsurgery are not available everywhere.
Local flaps also provide better colour match.
Advantages of fasciocutaneous flaps are ease of
elevation, less bulk, high reliability, easier transfer in
comparison with muscle of musculocutaneous flaps.
Lateral Supramalleolar flaps are fasciocutaneous flaps,
alternative to free flaps for reconstruction of ankle and foot defects.
As a rotation flap it can also be used for reconstruction
for defects in medial aspect of distal third leg also Proximally
based flaps are used to reconstructive defects around ankle.
Distally based flaps are used to reconstruct whole of
dorsum of foot, medial and lateral arches of foot or the heel region.
It is also useful to cover defects of stump resulting from
transmetatarsal amputations. Donor site is covered by split skin grafts.
AIMS AND OBJECTIVES:
The aim of this study is to evaluate the usefulness of
anastomosis around the lateral malleolar region in raising a
fasciocutaneous flap for soft tissue reconstruction of ankle and
foot defects and to ascertain the dimensions in raising a flap
within the safe limits.
MATERIALS AND METHODS:
Using Lateral supramalleolar flap as a versatile reconstructive tool for defects in ankle and foot. Duration of the study: September 2006-April 2009.
Venue of the Study: Department of Plastic, Reconstructive, Maxillofacial
surgery, Madras Medical college, Government General Hospital and Department of Anatomy, Madras Medical College.
Patient Selection Criteria:
1) 20 in number, 2) Patients with defects in ankle and foot regions, 3) No exclusion criteria, 4) Pre-operative Doppler study was done with 8MHz hand held Doppler.
Method of the Study:
After measuring the exact defect size, planning of
Lateral Supramalleolar flap is done. The flap is raised from
lateral aspect of lower leg . It is based on the Peroneal artery
perforator communicating to the lateral malleolar artery
anterior branch as a proximally based flap or as a distally
based flap based on the communications of lateral tarsal artery
at the level of sinus tarsi. Based on the site and the size of
required flap it is based either proximally or distally.
Dissection is proceeded from leg to foot. The superficial
peroneal nerve along with the superficial peroneal nerve
artery which is a branch of anterior tibial artery is included in
all the flaps. This flap is a neurocutaneous flap with the
inclusion of superficial peroneal nerve. It is also a reverse flow flap.
Measurements were made with digital calipers and
scales. Patterns were cut. Planning in reverse were also done
to take required length of pedicle. Digital photography were taken.
Cadaver dissections were done in which the peroneal
artery perforators and the communications with anterior
lateral malleolar artery and communications at the level of
sinus tarsi with lateral tarsal artery were confirmed.
OBSERVATIONS AND RESULTS:
1) The flap was mainly raised within the dimensions
described, the middle of the leg, anteriorly the crest
of the tibia, posteriorly, the fibula and distally the
anastomosis with the anterior lateral malleolar
artery in proximally based flap and upto sinus tarsi
in distally based flaps.
2) There were 20 patients in the study, 13 males and 7 females.
3) The soft tissue defects were due to; a) Post traumatic, b) Post infective,
c) Post burns scar contracture, d) Neoplastic excisional defect.
4) Diabetic status of the patients were included, 6 patients were diabetic.
5) The sites of soft tissue defects included; a) Dorsum of foot, b) Malleolar region,
c) Tendo Achilles region, d) Ankle region.
6) Out of 20 cases, 2 were distally based and others were proximally based flaps.
7) The length of pedicle on an average ranged between 4-6cm for proximally based and 11-13cm for distally based flaps.
8) The standard markings for the flaps were crossed in 4 cases, that is the upper limit was extended beyond the middle of the leg for 1-3 cms.
9) The site of emergence of the Ramus Perforans ranged from 4.6-5.2 cms
10) The average size of the soft tissue defect was about 4*3cm to 7*4 cms.
11) Regarding anatomical variations encountered in the dissections, in one case Ramus Perforans was larger and there were no communication with anterior lateral malleolar artery, a proximally based flap was raised to cover a defect in the dorsum of foot.
12) Complications: a) Donor site graft loss in one case,
b) Distal necrosis in two cases (one case territory of middle of leg was crossed and other was due to pedicle kinking),
c) Venous congestion in two cases which settled in two days.
13) Necessity of second surgery in above three cases,
14) All patients had full range of movement across the ankle joint,
15) The donor site in the lower third leg graft site settled well and patients usually covered these sites with pants or saree.
CONCLUSION:
1) The Lateral Supramalleolar flap based on the
anastomosis around the ankle lateral malleolar region
is a reverse flow flap useful in the reconstructions of
the defects in ankle and foot regions.
2) Preoperative Doppler is required to confirm this
anastomotic network before planning the flap.
3) The flap is limited to the dimensions of middle of
the leg above, medially crest of tibia and laterally
fibula. It can be raised as proximally based on the
Ramus perforans or distally based on the
communications at the level of sinus tarsi.
4) It is a local flap which gives good colour match,
texture and thickness to cover the exposed tendons,
bones and vessels in the foot and ankle regions.
5) Even though donor site morbidity occurred, the
ankle joint movements were well restored
