variation in termination of ulnar nerve in … journal of advance researches in biological sciences,...

326 Journal of Advance Researches in Biological Sciences, 2013, Vol. 5 (4) 326-330

Variation of Termination of Ulnar Nerve ............

1 2 3 4Gindha G. S. , Kaushal S. , Kalyan G. S. , Sharma A.1Department of Anatomy, Gian Sagar Medical College & Hospital, Ram Nagar, Patiala2 4Department of Anatomy, Department of Surgery, Maharishi Markandeshwar University, Mullana, Ambala3Department of Anatomy, Government Medical College, Patiala

Submitted on : -14-07-2013 Resubmitted on :-30-11-2013 Accepted on:-20-12-2013

VARIATION IN TERMINATION OF ULNAR NERVE IN HAND (TRIFURCATION OF ULNER NERVE)

INTRODUCTION

Few structures of the human body are unique and hand is one of

them. For the normal functioning of hand the ulnar nerve plays a

very important role. The ulnar nerve is the continuation of the

medial cord of the brachial plexus. Its root value is C8 and T1 but

often receives fibers from ventral ramus of C7 to form the root of

the ulnar nerve. It has no branches in the upper arm. It enters the

posterior compartment of the upper arm midway down its length

by piercing the medial intermuscular septum and passes behind

the medial epicondyle of the humerus to enter the forearm. It

passes to the wrist deep to flexor carpi ulnaris, giving branches to

this muscle and to the ulnar half of flexor digitorum profundus

muscle. Just proximal to the wrist it gives off a dorsal cutaneous

branch that supplies to the skin over the dorsal aspect of the little

finger and ulnar half of the ring finger. The ulnar nerve crosses

into the palm superficial to the flexor retinaculum in Guyon's

canal. It divides into a motor branch, which supplies the

hypothenar muscles, the intrinsics (apart from the radial two

Corresponding Author:

DR. G. S. GINDHADepartment of Anatomy

Gian Sagar Medical College & Hospital

Ram Nagar, Patiala-140601, Punjab (India)

E-mail : [email protected]

lumbricals) and adductor pollicis, and cutaneous branches,

which supply the skin of the palmar aspect of little finger and 1ulnar half of ring finger.

Unusual presentations following nerve injury can often be

explained by anomalous neural intercommunications. One such

variation of the peripheral nerves of the upper limb is the Martin- 2Gruber anastomosis in the forearm. Such a communication may

represent a pathway for redirecting nerve fibres that was not 3

completely separated in the brachial plexus. Cases are reported

in which the flexor pollicis brevis muscle was innervated by ulnar

nerve only. In one of these fibers ran in the median nerve at a

higher level, but crossed to the ulnar nerve at wrist. The incidence

of superficial communications between the median and ulnar

nerves varies throughout the literature. It was found in 80% of the 450 cadaveric specimens.

The ulnar nerve entered the hand superficial to the flexor

retinaculum in Guyon's canal, undercover of volar carpal

ligament and palmaris brevis muscle. It divided just proximal to

the pisiform bone into three branches: superficial, deep and

muscular branches. The superficial passing deep to the palmaris

brevis divided into palmar digital branch proper to medial side of

the little finger, and a common palmar digital branch for the

fourth interosseous space. The deep branch crossed the

pisohamate ligament and passing deep to the fibrous arch of the

flexor digiti minimi brevis, it penetrated the opponens digiti

minimi. The muscular branch entered the hypothenar eminence

ABSTRACT

Variations in the division and supply of nerves in hand are highly significant clinically to the hand surgeons and orthopaedicians. The

trifurcation of ulnar nerve was found in 7 hands out of 50 hands. 5 hands were of male sex( 3R & 2L) and 2 hands of female sex (2L).

Usually palmar aspect of hand is supplied by ulnar nerve and median nerve. Medial one and a half fingers are supplied by ulnar nerve and

lateral three and a half fingers are supplied by the median nerve. The branches of ulnar nerve are notoriously variable morphologically and

no standard pattern can be given regarding the course of these branches. The presence of trifurcation of ulnar nerve usually does not cause

any symptoms and is of academic interest only. It can become problem for surgeons and hand surgeons when they perform surgery on

hand. If the surgeons perform surgery without keeping such variations in their mind then the complication such as neuropathy can result

after surgery. So the surgical procedures in hand should be planned carefully keeping in mind in advance such variations which can be

encountered.

Key Words : Ulnar Nerve, Trifurcation, Variations, Brachial Plexus



lateral to the pisiform bone and supplied the deep, intermediate

and superficial heads of the abductor digiti minimi. The deep

branch supplied the flexor digiti minimi brevis, opponens digiti

minimi and another branch to the superficial head of abductor 5digiti minimi.

Niitsu, Kokubo & Nojima (2010) studied the ulnar nerve in 30

cases by using ultrasound and 3T MRI. They reported that out of

30 hands, 21 (70%) revealed bifurcation and 9 (30%) had

trifurcation branching pattern of the ulnar nerve. In 16 hands

(54%), imaging demonstrated that a single nerve entered the

canal and divided into two trunks, one superficial and one deep,

then exited the canal. The bifurcation occurred predominantly

just after entering the canal inlet. The typical trifurcation pattern

indicated that a single trunk entered the canal and divided into

two, then one of the two bifurcated, producing a trifurcated

pattern with two superficial and one deep bundle. Of 15

participants, symmetrical branching of bilateral hands was

identified in 4 cases (27%), whereas 11 (73%) had asymmetrical 6branching.

Lindsey and Watumull (1996), studied 31 fresh adult upper

extremities to delineate the regional anatomy of the ulnar nerve

and artery at the wrist. Two pattern of division of the ulnar nerve

trunk were identified: A and B. Three patterns of hypothenar

muscle innervation type 1,2 and 3 and two patterns of vascular

supply to the hypothenar musculature type 1 and 2 were also

identified. Pattern A occurred in 25 of the specimens where the

ulnar nerve bifurcated into a main sensory trunk and a motor

branch. Pattern B occurred in 6 of the specimen ulnar nerve

trifurcated into two common digital sensory branches and a 7motor branch. Hughes (1995) studied 10 adult hands to re-

examine in new detail, the distribution of the deep branch of the

ulnar nerve from its origin in the ulnar tunnel to its termination in

the first dorsal interosseous muscle. The relationships of

subdividing branches to each other and to the muscle bellies

were classified. The dorsal interossei were innervated within the

proximal third of their corresponding metacarpals, and 3rd

lumbrical was innervated within the middle third, whereas the 8fourth lumbrical was innervated along its distal third.

Ghabriel & Makar (2011) described trifurcation that the ulnar

nerve just proximal to the pisiform bone. Trifurcation of the

ulnar nerve proximal to Guyon's canal was seen in left hand of a

cadaver. They reported that the nerve divided into deep and

superficial divisions and a separate muscular branch that

supplied three heads for the abductor digiti minimi. An unusual

loop of the dorsal cutaneous branch of the ulnar nerve

communicated with this muscular branch and with the digital

sensory branches of the superficial division of the ulnar nerve.

The connection to the muscular branch is novel and has not

been described previously. The abductor digiti minimi had three

overlapping heads. The median nerve above the flexor

retinaculum appeared on the ulnar side of radially positioned

5palmaris longus tendon. Denmann (1977) reported a case in

which a branch passing from the deep terminal branch of the

ulnar nerve from digital to the piso-hamate hiatus between the

flexor digiti minimi brevis and the opponens digiti minimi to the

digital branch of the superficial terminal branch of the ulnar 9nerve to the little finger.

Keiichi Murata et al (2004) showed the variations of hypothenar

muscles and the arborization pattern the ulnar nerve and the

relationship between the hypothenar muscles and the ulnar

nerve. The study was performed on 35 hands from embalmed

cadavers. After dissecting the ulnar side of the hands they

recorded the number of hypothenar muscles and their variation.

There were connections between this branch and the branches of

the superficial branch of the ulnar nerve, which innervated the

skin of the hypothenar eminence. Further another branch of the

superficial branch of the ulnar nerve passed under the fibrous

arch of the flexor digiti minimi brevis muscle origin, and the 10opponens digiti minimi muscle to reunite with its parent nerve.

McCarthy (1980) have shown variation in digital nerve sensory

pattern of ulnar nerve in which a double sensory branch in the

canal of Guyon passes around the pisiform and joins the medial 11,12palmar digital nerve to the little finger.

MATERIAL AND METHODS

The present study was conducted in the Department of Anatomy

of Govt. Medical College Patiala. Study was done on 25

embalmed human cadavers (50 hands). Both hands were

dissected carefully and traced branches of ulnar nerve in hands.

Out of these 25 cadavers 20 cadavers were of male sex and 5

cadavers were of female sex. Both right and left hands were

dissected and the variations in the ulnar nerve and its

distributions were observed and photographed and compared

this study with the previous studies.

OBSERVATIONS

Out of 50 hands dissected (40 male and 10 female). The

trifurcation of ulnar nerve was observed in 7 hands. 5 cases

were of male sex( 3R &2L) and 2 cases of female sex(2L).

Total Number

50

Male

40

Female

10

Table-1 : Showing number of hands

Total Number

50

Right Hand

25

Left Hand

25

Table-2 : Showing side of hands



Total Number

43

7

Table-3 : Manner of division of main trunk of ulnar nerve in 50 hands

Sex

Male

35

5 (3R & 2L)

Female

8

2(2L)

Right

21

3

Manner of

termination

Bifurcation (1 superficial & 1 deep)

Trifurcation

Side

Left

22

4

In four cases of trifurcation of ulnar nerve which were of male sex

three were of right side and one case was of left side.

(I) In one case of left side(unilateral) ulnar nerve gave 2

superficial branches and one deep branch. 1st superficial

branch supplied to palmaris brevis muscle, 2nd superficial

branch again divided into 2 digital branches, one branch to

PDDB and one to CPDB and also supplied to the medial one

and a half fingers.Deep branch supplied to the hypothenar

muscles i.e. medial two lumbricals, all interossei and

adductor pollicis.

(ii) In 3 hands , 1(unilateral) and 1pair(bilateral) ulnar nerve

again divided into 2 superficial and 1 deep branches. Out of

which one superficial branch supplied to palmaris brevis

muscle and PPDB for ulnar side of little finger. Second

superficial branch supplied to CPDB, cleft between little and

ring finger. The deep branch supplied to the hypothenar

muscles, medial two lumbricals, all interossei and adductor

pollicis.

In 3 hands 1 M(unilateral R ) and 2F (unilateral L) ulnar nerve

divided in 1 superficial and 2 deep branches.

1st deep branch in right hand supplied to ADMD and PB muscles

2nd deep branch supplied to hypothenar muscles, medial two

lumbricals, all interossei and adductor pollicis muscles.

One superficial branch supplied to 2 digits i.e. to the medial one

and a half fingers.

One case of left hand ulnar nerve divided into 2 deep branches

and one superficial branch. ADMB, FDMB and PB supplied by 1st

deep branch and 2nd deep branch supplied to hypothenar

muscles, medial two lumbricals and all interossei. The superficial

branch supplied to PB and medial one and a half digits.

In 3rd case of left hand the ulnar nerve gave rise 2 deep and one

superficial branch. The 1st deep branch supplied to ADMB,

FDMB and PB muscles. Whereas 2nd deep branch supplied to

hypothenar muscles, medial two lumbricals, all interossei and

adductor pollicis muscles. The superficial branch supplied to PB

muscle and medial one and a half digits.

Number of

Hands

4

3

Table-4 : Division of ulnar nerve in 7 cases of trifurcation

Sex

Male

4

1

Female

0

2

Right

2

1 (unilateral)

M

1

1 (unilateral)

M

Branches

2- superficial, 1-deep

2-superficial, 1-deep

2-deep, 1-superficial

Side

Left

2

1 (unilateral)

M

2

2 (unilateral)

F

Bilateral

M

DISTRIBUTION OF ULNAR NERVE IN 7 CASES OF TRIFURCATION.



DISCUSSION

Lindsey and Watumull (1996) observed two patterns of division

of ulnar nerve in hand i.e. A & B. Pattern A occurred in 25 out of

31 (80.6%) specimens, where the ulnar nerve bifurcated into a

main sensory trunk and a motor branch. Pattern B occurred in 6

(19.4%) specimens in which ulnar nerve trifurcated into two 7common digital sensory branches and a motor branch.

Keiichi Murata et al (2004) identified 4 branching pattern of the

motor branch. ADM coming from the deep branch of ulnar nerve

in 35 cases in cases type 3 in 8 hands the ulnar nerve trifurcated

into a superficial trunk, a deep branch and a motor branch to 10ADM in Guyon's canal. Bonnel and Vila (1985) reported

trifurcation of ulnar nerve just proximal to the pisiform bone.

Trifurcation was reported previously in 11 (22%) out of 50 cases 13 and in 4 of these trifurcation occurred in Guyon's canal.

In presence study 7 (14%) cases out of 50 cases of trifurcation of

ulnar nerve were found. The ulnar nerve trifurcated to supply to

the ring finger by common digital branch, the ulnar proper digital

nerve to the little finger and a deep branch just digital to the

digital edge of pisiform bone. Trifurcation was found bilaterally in

one case only whereas in 5hands it was a unilateral anomaly.

SUMMARY AND CONCLUSION

The presence of trifurcation of ulnar nerve anomalous variation,

usually it doesn't cause any symptoms of academic interest only.

It becomes a surgical problem when anomalous variation

produces symptoms and causes neuropathy. Morphological

understanding about the neural branching pattern can be

informative in presurgical planning and also in diagnosis for hand

surgeons and orthopaedicians. Hence the surgical procedure in

this important region i.e. hand should be planned carefully in

advance keeping in mind all the variations which can be

encountered.

NPB coming from SB, along with Trifucation pattern with two

deep & one Superficial branch & nerve to ADM coming from

MTUN

MTUN-Main trunk of Ulnar Nerve

SB- Superficial branch of Ulnar Nerve

DB1 (N. ADM)- First deep branch of Ulnar Nerve going to ADM

DB2- 2nd deep branch of Ulnar Nerve

NPB- Nerve to Palmaris brevis

Photograph-1 Figure-1



Nerve to Palmaris Brevis coming from Deep branch of Ulnar

Nerve along with Trifucation pattern with two Superficial & one

Deep branch

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2. Tubbs RS et al: A case report, retained hand function

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hand Journal hand surgery (Br) 1985; 10:165-168.

MTUN-Main trunk of Ulnar Nerve

DB- deep branch of Ulnar Nerve

NPB- Nerve to Palmaris brevis

SB1- First Superficial branch of Ulnar Nerve

Sb2- Second Superficial branch of Ulnar Nerve

Photograph-2

Figure-2

variation in termination of ulnar nerve in … journal of advance researches in biological sciences,...

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