Background: Pressure sores are still a
serious problem for paraplegic patients. For these patients,
debilitating pressure sores in the ischial region, which is the
primary weight bearing area, present a difficult problem. While
there are various wound coverage procedures available, the
chance of recurrence exists because of insensate skin and
enormous pressure. The recovery of sensibility is of great
importance, especially over the ischial area.
Methods :The aim of our study is to
provide a method to cover ischial sores with a sensate flap. A
dissection of five cadavers was undertaken to work out the
feasibility of this sensate flap. The skin component of tensor
fascia lata flap which is innervated by the lateral cutaneous
nerve of the thigh was utilized to cover the ischial sore. The
anterior cutaneous branches of intercostal nerves from T10-T12
were used as the donor nerves. The recipient nerve was the
lateral cutaneous nerve of the thigh.
Results:Our dissection revealed that
this technique of sensory reinnervation is possible. The anatomy
was found to be consistent in all dissections. The length of the
anterior cutaneous branch of intercostal nerves permitted
tension free approximation of the donor and recipient nerves in
all cadaver dissections.
Conclusions:Appropriate candidates for
this sensory flap are patients who have spinal cord damage at
the thoraco lumbar junction. Clinical application of this
sensate flap will be attempted when a suitable candidate is
available. The results need to be analyzed carefully to assess
the degree of return of sensation. It also needs to be
established whether the addition of sensory stimulation to the
flap would contribute greatly to the long term flap viability.
pressure sores; Tensor fascia lata flap; Sensory reinnervation
In normal individuals, prolonged soft tissue
compression results in discomfort and pain secondary to local
ischemia. Neural signals provided by the nociceptive afferent
nerve fibres in these areas lead to reflex or volitional
adjustment of posture. These positional changes are sufficient
to relieve the pressure and thereby reverse the ischemia and
also wash away the accumulated pain substances. Interrupted
sensory pathways in the paraplegic patients prevent these normal
adjustments. To avoid tissue necrosis and ulceration paraplegic
patients one must frequently alter their position or use
expensive floatation mattresses. The other alternative to get
back some sensations to their weight bearing areas is by some
Neurovascular flaps can be used to restore
sensation; however their application in paraplegics is extremely
complex. The recovery of sensibility is of great importance,
especially over the ischial area.
The aim of our study is to provide a method
to cover the ischial sores in paraplegic patients with a sensate
Material and Methods :
The basic concept is that an insensate flap
can be reinnervated by suturing its supplying nerve to a donor
nerve rotated down from above the level of insensitivity.
A dissection study was undertaken on five
cadavers to work out the feasibility of this sensate flap.
Appropriate candidates for this sensory pedicle flap are
patients who have spinal cord damage at thoracolumbar junction
presenting with recurrent ischial or greater trochanteric sores.
The anterior cutaneous branch of the
intercostals nerves from T10 to T12 was used as the donor nerve
(Figure 1A and Figure 1B ) which was rotated down towards the
iliac crest. The recipient nerve was the lateral cutaneous nerve
of the thigh (Figure 2A) supplying the skin component of the
tensor fascia lata flap used to cover the ischial sore.
Theoretic possibility of sensory reinnervation (Figure 2B) was
demonstrated after tension free approximation of both the donor
and recipient nerves fascicles at iliac crest level in all
The dissection and isolation of the anterior cutaneous branch of
the intercostal nerves is shown.
Figure 1B- Course of nerve
The course of the anterior cutaneous branch of the intercostals
nerve (high up) is shown.
Lat Cutaneous N
The course and dissection of the lateral cutaneous nerve of the
thigh is shown.
Figure 2B- N approximation
The approximation of the anterior cutaneous branch of the
intercostals nerve and the lateral cutaneous nerve of the thigh
Result of Cadaver Dissection
Our cadaver dissection revealed that this technique of sensory
reinnervation by rotating the donor nerve (anterior cutaneous
branch of the intercostal nerves) to the recipient nerve
(lateral cutaneous nerve of the thigh) is technically feasible
in paraplegic patients especially presenting with recurrent
ischial sores . Hypothetically, the first stage should be the
flap rotation to cover the pressure sore followed by sensory
reinnervation procedure at three weeks interval, once adequate
soft tissue haling has been achieved.
Consistence of anatomy
There was consistence of anatomy of both the donor and recipient
nerves. The length of the anterior cutaneous branch of the
intercostal nerves permitted tension free approximation in all
cases at the iliac crest level, near the anterior superior iliac
1) Patients with spinal cord damage at thoraco lumbar junction
level presenting with recurrent sores or unstable scars.
of soft tissue material due to extent of the sore.
of adequate padding due to anatomical changes.
overall incidence of pressure sores has decreased over the last
few decades due to the better understanding and availability of
preventive measures supplemented by improved nursing care.
Despite these advances, pressure sores are still a serious
problem for paraplegic patients, who are confined to a wheel
chair. It has been widely acknowledged that the results of
various available treatment procedures, in general have been
less then satisfactory.
factor of rehabilitation of paraplegic patients is the
prevention of pressure sores , by education of the medical
and nursing staff, the patient and patient’s family and by
recognition and identification of high risk patients.
includes patients with reduced mobility, reduced or absent
sensation, loss or decrease in vasomotor control and alteration
Reconstructive surgery  must be considered in patients not
responding to the conservative treatment:
problem of pressure sores  suffered by wheel chair bound
patients can not be approached simply with the objective of
closing ischial decubitus ulcers or by ischialectomies. The
tissue in that area must be able to stand up to the rigors of
life in a wheel chair, and if an ulcer is treated with a simple
wound closure, the problem is likely to recur.
there are various wound coverage procedures available , the
chance of recurrence exists because of insensate skin and
enormous pressure and a different approach to the problem is
required, one which confronts the underlying cause. The aim is
to restore sensation to the critical area with a sensate flap.
techniques cited in the history to treat the pressure sores are:
(Guttmann) - Excision of the lesion, resection of bony
prominences by following his pseudo tumour technique and
coverage of the defect with a large transposition rotation skin
and Medgyesi) – Padding the sore cavity by using muscle flap
underneath the skin flap, but without neurovascular bundle
et al) – Musculocutaneous flaps
flap for coverage of lumbosacral region is not a straight
forward procedure mainly because of lack of the recipient
vessels. In addition the surrounding unhealthy tissue and poor
general condition of the patients makes it even more complicated
and often with not much reward.
amount of training can replace the timely and highly motivating
sensory experience called pain. Placement of sensory flap at the
site of pressure intimately links cause and effect. It also
provides the direct reminder of pain stimulus to the brain,
which appears to be the basis for the success of a sensory skin
upper quadrant flap  is a useful alternative in the repair of
pressure sore defects of the sacral region and also the donor
site is not disabling [5, 6]. Use of a long island flap to bring
sensation to the sacral area in young paraplegics is very
promising but the nerve bundles of T-10 and T-11 are not long
enough to reach down to the dangerous pressure areas over the
ischial tuberosities or the sacrococcygeal prominence and also a
very large decubitus ulcer could not be closed by the island
flap itself. In patients with injury level below L3-L4, a tensor
fascia lata musculocutaneous flap based on lateral cutaneous
nerve of thigh (L1, L2, and L3) can be used to provide
sensations to the defected area but not in patients with lesion
above this level.
our cadaver dissection raises a hope for a kind of sensory
reinnervation in paraplegics with lesion at the thoracolumbar
junction, in which the sensory component of the intercostals
nerves can be utilized to provide the sensation to the skin flap
covering the ischial weight bearing sores.
precautions need to be taken before one embarks on the tensor
fascia lata- intercostals flap.
Sensory innervated tensor fascia lata flaps should be performed
only in recurrent sores when conservative treatment has failed.
should be intelligent enough so as to be able to ‘relearn’ the
Rehabilitation must have reached an adequate level, and the
patient must be cooperative.
neurological status of the patient has to be stable.
need the whole length of the flap to reach the ischial region
the length of the leg has to be considered.
Postoperatively the patient has to be kept on special pillows to
keep the ischial region free of pressure; otherwise the nerves
may get damaged.
procedure can be very rewarding for the patient as the formerly
anaesthetic region is converted into a sensitive area, thereby
helping the patient to sit and thereby increase sitting control
in a wheel chair .
Reinnervation of the flap is a much more complicated problem.
First the surgeon must identify the one fascicle that can
reinnervate the flap (out of the 5-7 which comprise the
intercostal nerve). Then it has to be rotated down without
damage to be the donor nerve. A tension free approximation must
be performed between the donor and recipient lateral cutaneous
nerve of the thigh. For success of the reinnervated flap the
patient must be educated to use the available sensation. The
stimulus may be referred to the wrong site (donor site) -
because the cortical representation of the flap has not changed
from the intercostal area of somatosensory cortex. This appears
as a minor problem of readjustment. Once the sensory stimulus of
pain is felt by the patient, he will learn how to relieve the
discomfort felt on his thorax and make the proper postural
readjustments automatically. We would emphasize the value of
electrophysiological study for solving these problems.
ideal candidate for this flap is a patient with paralysis at the
thoracolumbar junction level, presenting with recurrent pressure
sores due to insensitivity. Clinical application of this sensate
flap will be attempted when a suitable candidate is available,
as a large population of presenting patients have higher spinal
cord lesions. The results will be analyzed carefully to assess
the degree of return of sensation. It will also be determined
whether the addition of sensory stimulation to the flap would
contribute greatly to the long term flap viability.
List of Abbreviations
Lat: lateral, N: nerve
The authors declare that they have no competing interests.
RG did manuscript writing and literature search, TA
performed cadaver dissection and concept design, SKA performed
manuscript writing and critical revision, BKKF performed cadaver
dissection and concept design, WYI performed cadaver dissection,
SPC performed concept design and final approval of the
We acknowledge the help of Department of Anatomy, The University
of Hong Kong for providing the cadaver for dissection and the
necessary logistic support.
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