Page 43 - Read Online

Page 6 of 15 Dellon. Plast Aesthet Res 2022;9:45 https://dx.doi.org/10.20517/2347-9264.2022.13

SURGICAL DECOMPRESSION
The main concept is that the stocking distribution of symptoms present in diabetic neuropathy can be
understood as compression of the peroneal and tibial nerves. The original approach I took to surgical
decompression required understanding that the tarsal tunnel is NOT the carpal tunnel anatomically
[65]
[Figure 3] , but is the forearm, with the carpal tunnel being the medial plantar tunnel, the Guyon’s canal
being the lateral plantar tunnel and the compression of the palmar cutaneous branch of the median nerve
[66]
being homologous with compression of the medial calcaneal nerve . Therefore instead of simply
decreasing the tarsal tunnel, the operative treatment must be conceived of as releasing the tarsal tunnel and
a neurolysis of the medial and lateral plantar and calcaneal nerves; four medial ankle tunnels, or
[67]
tarsal tunnel syndrome . To perform this surgery successfully, the septum between the medial and lateral
plantar tunnels must be removed [Figure 4], as has been demonstrated by measuring compartment
pressures in both cadavers and patients having this surgical decompression .
[68]
[69]
The anatomical basis of these techniques has been described for the deep peroneal over the dorsum of the
[71]
foot [Figure 5] , the common peroneal nerve at the fibular neck , and variations of the superficial
[70]
peroneal nerve in the leg [Figure 6 ] . The actual surgical techniques for the four medial ankle tunnels are
[72]
illustrated in Figure 4 and have been described in detail in the past [73-75] . Videos of the surgery can be viewed
on YouTube.com for the tarsal tunnel decompress (https://www.youtube.com/watch?v=c
oBfi9NDjUM&t=36s) and the peroneal nerve decompressions (https://www.youtube.com/watch?v=Qlt
e57IHBzE&t=37s).

When should you consider neurolysis of the superficial peroneal nerve? The superficial peroneal nerve most
always exits from the fascia of the lateral compartment about 6 to 8 cm proximal to the lateral malleolus.
Sometimes there is a small bulge marking the spot. If there is a positive Tinel sign at that site, then
neurolysis of this nerve should be added to the classic Dellon Triple. This can easily be added to the
operation without additional post-op rehabilitation or morbidity but remember to use the bipolar cautery
along the edge of the fascia before dividing the fascia to minimize post-operative bruising.

For the peroneal nerve, the multiple crush concept extends the double crush concept as follows; The first
source of reduced axoplasmic flow is diabetes itself, with compression of the common peroneal nerve being
the second crush, the superficial peroneal nerve being the third crush site, and the deep peroneal nerve
being the fourth site. The first site cannot be changed. Theoretically, the vertebral foramen and the sciatic
notch could be added, but as a matter of practicality, these sites are not easily decompressed, so they are not
included. What can be approached safely are the common, superficial, and deep peroneal nerves. Although
it is not clear experimentally that all need to be decompressed, if there has been a Tinel sign present, then
that site is included in the surgical approach. Also, remember to open the anterior compartment, as 25% of
people will have a branch of the superficial peroneal nerve located in this compartment [Figure 6] .
[76]

For the tibial nerve, a site proximal to the tarsal tunnel had not been identified until 2009 [76,77] . This clinical
problem was raised not in the setting of neuropathy but in the setting of “failed tarsal tunnel
decompression”. It is well documented in upper extremity surgery that a “failed” carpal tunnel release can
be due to proximal compression beneath the pronator teres deep head. A similar site in the lower extremity
would be the fibrous arcade of the soleal sling, which gives origin to the soleus muscle. This site is at the
soleal sling [Figure 6] and is identified clinically by two physical exam findings: weakness of the flexor
hallucis longus and tenderness in the calf about 8 cm below the knee joint, a site similar to that of the
Homan’s sign for deep vein thrombosis. Sometimes a 3T MRI will show changes in the tibial nerve at this
location, but it is unusual for the electrodiagnostic testing to be abnormal. The surgical technique has been