Case 8: Six week delayed presentation of above elbow level ulnar nerve transection injury.
CHIEF complaint: Right arm laceration with loss of ulnar nerve function.
HISTORY OF PRESENT ILLNESS: This is a 61-year-old right-hand-dominant pastor who was working on repairing his 110-year-old Victorian house six weeks ago. He, unfortunately, felt the ladder collapse underneath him and fell through a glass window, sustaining lacerations to the area proximal to his elbow. He was seen at an outside hospital emergency room, washed out, and the lacerations were repaired. He states that immediately he noted loss of sensation in the small and ring finger. He also notes that he had great difficulty using the hand since then. He was subsequently evaluated by his primary care doctor as well as a hand surgeon near his home, and found to have a complete transection of the ulnar nerve at the level of the proximal laceration. He had EMGs and nerve conduction studies which corroborated that diagnosis and was subsequently referred or further management.
Of note, the patient notes that he has significant neuropathic pain which has improved somewhat over the last couple of weeks. He is compensating and has started writing again with his right hand.
He does note a history of a right ring finger injury in the past with residual PIP joint stiffness at baseline, and he is not sure if he was able to bring that finger down to the palm preinjury.
social history: The patient lives with his wife. They live approximately two and a half hours a way. He works as a pastor and restoring his 110-year-old house and obviously has a lot of hand intensive hobbies. No tobacco, alcohol or drug use.
MEDICATIONS/ALLERGIES/PAST MEDICAL And Past Surgical HISTORY/ family history/Review of systems: Significant only for the right ring finger trauma and a remote left shoulder dislocation.
PHYSICAL EXAMINATION: General: He weighs 200 lb and is 5’11” tall. He is an alert, white male in no acute distress. He did fill out the pain questionnaire. Please refer to that for details.
Pinch on the right is 8. On the left it is 24. Grip on the right is 50. On the left it is 95. Two-point discrimination on the right median nerve distribution is 4 mm. On the left it is 3 mm. Two-point discrimination in the ulnar nerve distribution on the left is 2 mm. On the right he has no sensation.
On examination of the arm, he has an oblique laceration at the arm medial aspect approximately 10 cm proximal to the elbow. He has a Tinel’s sign just proximal to this laceration site in the area of the ulnar nerve. Distally he has a jagged laceration just distal to the elbow. There are no Tinels at this site. He also has a laceration over the dorsal aspect of the forearm just distal to the elbow. There is no Tinel’s there. He has normal extension of the fingers and wrist. He has normal prono-supination with 5/5 power. He has normal biceps and triceps function. On examination of his ulnar nerve function, he has no function of the flexor carpi ulnaris, the FDP to small finger, and no function of the intrinsic musculature of his hand with no ability to cross the fingers, a positive Froment’s sign, and diminished pinch.
His passive and active range of motion of the PIP joint of the ring finger is diminished. His FDS to all of his fingers is intact and normal. He has active palmaris function. He has normal flexor carpi radialis function. He has normal filling at the palmar arch from both the ulnar artery and radial artery, indicating no distal injury of the ulnar artery. The remainder of his sensation is normal. He does have a small burn that is approximately a half of a centimeter at the distal ulnar aspect of the small finger which he sustained immediately after the injury because of loss of sensation. He has had no further injuries. It appears noninfected, and he has been treating it with the antibiotic ointment.
Assessment and plan: Unfortunately, he has a high ulnar nerve transection injury. He is approximately a month and a half out from this injury. He continues to have some moderate neuropathic pain and obviously a significant loss of function due to the sensory and motor dysfunction. We discussed treatment options at length. A number of options exist. One is direct repair of the nerve, possibly requiring grafts if there is a significant segment of damaged tissue. I also am concerned about his ability to regain function of the intrinsic musculature of the hand. I think that our best option would be to do a distal motor transfer stealing from the pronator quadratus to more rapidly reinnervate the deep motor branch of the ulnar nerve. Although this will not give him perfect function, it will hopefully prevent clawing of the hand at the very least, and I certainly do not think that he has a good chance of reinnervating his intrinsic musculature with grafting proximal to the elbow due to his age as well as the length of regeneration required.
In terms of getting him sensation to the ulnar border of his hand, one option would be a sensory nerve transfer from the third web space to the ulnar border of the hand. However, the patient is not interested in sacrificing any function, but he would like to wait for the sensation to return from the primary grafting of the ulnar nerve. I told him this will likely take at least two years. He will need to protect the hand to prevent further burns and other problems. The patient is willing to do that, and I think that is certainly reasonable. I also did discuss side-to-side tenodesis of the FDP to ring and small finger to the remaining FDPs so that he can have better grip. The other things I would recommend would be ulnar nerve transposition, as this will shorten the time required for regeneration, as it would shorten the course of the nerve. I also would recommend release of Guyon's canal to promote better regeneration of the motor branch. The patient is amenable to that plan. We discussed things at length. I showed him pictures in an anatomy book to further improve his understanding. I also recommend that he start on amitriptyline to begin some control of his neuropathic pain.
PREOPERATIVE DIAGNOSIS (ES):
Right upper extremity laceration
POSTOPERATIVE DIAGNOSIS (ES):
Right complete proximal (proximal to elbow) ulnar nerve laceration with crush
NAME OF OPERATION: Right upper extremity
1. Exploration of ulnar nerve via extended proximal cubital tunnel release
incision using the previous laceration site as well as extending the incision.
2. Excision of early neuroma with repair using 8 cables of medial antebrachial
cutaneous nerve graft (4 centimeters in length each)
3. Ulnar nerve transposition with step lengthening of the pronator flexor
origin muscle mass, release of the ulnar nerve at the wrist/Guyon's canal with
special attention towards release of the deep motor branch of the ulnar nerve.
4. Nerve transfer of the pronator quadratus branch of the anterior
interosseous nerve to the ulnar nerve deep motor branch.
5. Side to side tendon transfers of the ring and small finger flexor digitorum
profundus to the index and long finger flexor digitorum profundus.
6. Use of the operating room microscope for the nerve repair as well as the
nerve transfer procedures.
INDICATIONS FOR PROCEDURE:
This is a 61-year-old gentleman who was involved in renovating his house. He
felt the ladder slip out from under him and fell putting his right elbow
through a glass window. He sustained numerous lacerations above and below the
elbow and was subsequently diagnosed with distal loss of function of the ulnar
nerve by physical examination, symptoms and nerve conduction
studies/electromyogram. He presented to my office almost two months after injury and
we talked about treatment options at length.
At the present time the patient would like to proceed with cable graft repair
of the ulnar nerve. I told him I would use branches of the medial antebrachial
cutaneous nerve which per examination seemed to be distally injured as well.
Another option I did offer him is a distal sensory transfer to bring in
sensation more quickly to the ulnar border of the hand especially in light of
his recent burn, however, the patient declined that not wanting the additional
donor site deficit.
We did also discuss options for treatment of the motor loss of function. These
included simple watchful waiting for regeneration through the grafted ulnar
nerve, however, as I told him unfortunately the distance is quite far and I
would not expect him to gain intrinsic hand function. He may gain extrinsic
hand function that is ulnar innervated. Therefore, I recommended and he agreed
to a nerve transfer procedure to bring nerve fibers from the pronator quadratus
to the deep motor branch of ulnar nerve. This may or may not be successful,
but will hopefully at least prevent a claw hand deformity, but he may require
additional procedures. The patient understands and would like to proceed. The
other thing we also talked about is doing a side-to-side tendon transfer to
give him full grip at the ulnar border digits and he agreed to that.
All of his questions were answered. He understands the multiple risks and
gives his consent. I reiterated that again that this is an extremely severe
and devastating injury. His hand function will never be the same. This was
explained to both the wife and the patient and I will continue to reiterate
that throughout. Unfortunately, also nerve injuries take a long time to show
progress after repair due to the slow nature of nerve regeneration. The
patient and his wife understand. All of their questions were answered and they
gave consent as noted.
DESCRIPTION OF PROCEDURE:
The patient was brought to the operating room and placed in the supine position
on the operating room table. Sequential compression devices were placed for
deep venous thrombosis prophylaxis and will be continued until the patient is
fully ambulatory. He was administered Ancef preoperatively and will be
continued on antibiotics perioperatively only.
First, we began by standard sterile prep and drape of the entire hand and arm.
Incisions were marked for access to the ulnar nerve at the elbow. We did have
to contour our incisions to continue the previously noted scars from his
initial injury and laceration. This, however, was relatively easy to do and
those lines were drawn for release of the ulnar nerve at the elbow. I next
made a longitudinal incision at the forearm level for access to the pronator
quadratus and proximal ulnar nerve as well as a continuation across the wrist
in a zigzag fashion to gain access to the ulnar nerve at the wrist for release
of it at Guyon's canal. Next, a sterile tourniquet was placed over the arm
after padding it with Webril. The arm was exsanguinated and the tourniquet
elevated to 250 mm/Hg. I first turned my attention towards isolating the nerve
proximally and a longitudinal incision was made and the skin and subcutaneous
tissue was elevated up off the area of the ulnar nerve dissecting through
significant scar tissue with some scarring within the lateral muscle belly and
within this we found the thickened end of the ulnar nerve with early neuroma
formation and a gap filled by scar tissue and then the distal ulnar nerve end
where it had been lacerated at the base of the proximal laceration scar.
Knowing this I then turned my attention towards doing the distal exposure as
quickly as possible. The contents of the carpal tunnel were retracted radially
giving access to the distal continuation of the anterior interosseous nerve
into the pronator quadratus. This was stimulated using the nerve stimulator
and noted to have excellent contracture of the pronator quadratus. I then
stimulated the ulnar nerve and as expected showed absolutely no contracture.
This was done within less than 1/2 an hour of elevating the tourniquet and in
fact the total tourniquet time was 37 minutes.
After we had isolated the pronator quadratus branch and the ulnar nerve at the
forearm I then proceeded to release the ulnar nerve at the wrist. A separate
incision was made initially leaving a skin bridge and dissecting down carefully
protecting the ulnar artery. The deep branch of ulnar nerve as it dove
underneath the hypothenar musculature was released by gently snipping the
leading edge of the fascia of the hypothenar musculature. Once this was
completely freed I then visually followed the ulnar nerve deep motor branch
proximally and ended up making the skin incision to completely isolate it and
allow clear visualization proximally all the way to the forearm level. I did
neurolyse some physically as well to clarify to myself that this was indeed the
deep branch of motor nerve. Then this recipient nerve was marked and I turned
my attention towards neurolysing the pronator quadratus branch both proximally
and distally into the muscle where it started to trifurcate. I cut the
pronator quadratus branch distally and then assessed the length of ulnar branch
motor nerve I needed. This was then cut proximally and the two ends were
brought together. Unfortunately, the deep motor branch had two rather large
fascicles in comparison to a single fascicle that was quite diminutive for the
pronator quadratus branch, however,I did feel that the best option at this
point would be to go ahead and do this nerve transfer as planned. Obviously
there are secondary procedures that could be done in case of development of a
claw hand and he may certainly require these, however, with 53 centimeters from
the level of the repair above the elbow to the intrinsic musculature I am
certain he will not gain any meaningful motor repair from that direct repair
proximally, thus the distal nerve transfer is quite justified and I think a
better option overall.
The proximal end of the deep motor branch was then sewn end-to-side into the
side of the remaining ulnar nerve to prevent regenerating sensory fascicles
from escaping and causing a painful neuroma.
Once this had been set up I then turned my attention back proximally and
proceeded to harvest the medial antebrachial cutaneous nerve which, actually,
had infract been been lacerated distally. This was followed back proximally
well up towards the axilla and in fact we had to remove the non sterile
tourniquet to get good proximal length to allow repair of the now significant
gap even with transposition of the ulnar nerve which I performed by freeing it
up circumferentially distally and completely bringing it up anterior out the
antecubital fossa. I also had to neurolyse several branches to the flexor
carpi ulnaris to allow successful transposition. I did use the flexor pronator
origin musculature fascia in a step lengthened fashion to create a sling to
later tie to allow the ulnar nerve to be tethered in place. I also did release
some of the vertical septations in the flexor/pronator muscle massand remove
these and create a nice bed for which the ulnar nerve to lay on. This in
effect step lengthened the pronator flexor origin.
However, as noted this did not create enough length for a tension free repair
of the lacerated ulnar nerve, therefore, I did go and harvest those medial
antebrachial cutaneous branches marking the proximal end to allow reversing to
prevent any branches of regenerating neurons from escaping out. We then brought
the reversed medial antebrachial cutaneous branches up and noted approximately
a total of 8 fascicles which were then proceeded to sew it together using the
operating room microscope. These were sewn side-to-side using 9-0 nylon sutures
to create a flap graft-like structure which I then rolled up and again sewed
the ends of the cylinder together using 9-0 nylon suture and then brought this
construct over to the proximal end of the ulnar nerve in the reversed fashion.
I then repaired these numerous small fascicles to the proximal end again using
9-0 nylon suture. I then attempted to keep the same orientation of these cable
grafts in their course distally and repair them to the distal end of the ulnar
nerve. Of note, I had previously bread loafed back with the patient with very
light anesthetic, however, his heart rate remained in the 70's throughout and
we based our cutting back on the presence of healthy appearing bulging
fascicles. Of note there was a significant scar and a likely component of
crush type injury at the site of laceration. After the cable graft had been
sewn in and the arm was noted to move easily through flexion and extension with
no tension on the graft I then proceeded to maintain the ulnar nerve transposed
anteriorly in place at the elbow by tethering it using a sling made of the
flexor pronator muscle fascia. This was very loosely repaired over the nerve
using 2-0 Ethibond horizontal mattress sutures. I also stuck a finger both
proximally and distally and noted the nerve to be completely released at the
elbow throughout. We then proceeded distally and with retraction we were able
to gain access to the pronator quadratus and deep motor branch nerve, which we
had previously tested noting no function in the ulnar nerve and normal function
in the branch to pronator nerve. These were then repaired using 9-0 nylon as
well. These were also under no tension and with flexion and extension of the
wrist there was no disruption of the repair. The wounds were all irrigated
copiously with normal saline prior to doing the nerve repairs and then
hemostasis was achieved using bipolar cautery.
We then went and performed the flexor digitorum profundus tenodesis or side to
side tendon transfers. This was done in a side to side fashion. First we set
the tension at the index and long finger using 2-0 Ethibond sutures. I then
set the tension for the ring and small fingers to each other again using 2-0
Ethibond sutures. I then set the tension to the index, long and small fingers
again using 2-0 Ethibond sutures with the small and ring finger slightly at
tighter tension than the index and long finger. After that was completed an on
Q pain ball catheter was placed. Also some 1/2% Marcaine was injected into the
wound. A 10 Blake drain was also inserted coming out proximally. It was sewn
in place with 3-0 nylon suture. The patient had his incision closed with
interrupted 3-0 Monocryl sutures, a running 4-0 subcuticular suture and at the
hand 4-0 nylon interrupted mattress sutures. A sterile Adaptic, 4 x 4's and
Webril dressing were placed. The patient was placed in a protective dorsal
blocking splint with the wrist flexed at about 10-20 degrees, the
metacarpophalangeal joints flexed at 90 and the interphalangeal joints at 100.
The thumb was left free. The patient was extubated and taken to the recovery
room in satisfactory condition.