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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.

 

Diagnostic Testing

(None)

Management

Pre-operative

Surgical:

 

PREOPERATIVE DIAGNOSIS (ES):

Right upper extremity laceration

POSTOPERATIVE DIAGNOSIS (ES):

Right complete proximal (proximal to elbow) ulnar nerve laceration with crush

component

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.

 

Post-operative

 

Patient Outcomes

Discussion

References