EXTERNAL FIXATION OF INJURED
NAIL BED WITH THE INRO SURGICAL
NAIL SPLINT
E. OLAYINKA OGUNRO, MD, FACS,
Dallas, Texas
From the Charlton Methodist Hospital; and the University of
Texas, Health Science Center, Dallas, Texas.
Reprinted from
THE JOURNAL OF HAND SURGERY,
St. Louis
Vol. 14A, No. 2, Pt. 1, pp. 236-241, March, 1989
(Copyright © 1989, by The C.V. Mosby Company)
(Printed in the U.S.A.)
External fixation of injured nail bed with the
INRO surgical nail splint
The use of the nail as a splint Is desirable in the management of acute nail bed Injuries. However,
when the nail plate Is destroyed and during secondary reconstruction of the nail bed, the nail
Is not available for use as a splint. Several substitutes, notably silicone sheet have been used,
but without much success. The INRO surgical nail, with qualities similar to the nail splint was
developed for use as a substitute. During the period of study from 1983 to 1985, 89% of patients
had good results. (J HAND SURG 1989;14A:236-41.)
E. Olayinka Ogunro, MD, FACS, Dallas, Texas
Publications by Zook and associates•"'
clarified the anatomy of the paronychium and stressed
the importance of anatomical reconstruction of the nail
bed. Contributions by Flatts. 6 McCash, 7 Shiller, 8 and
Asbell and colleagues, 9 directed attention to the proper
management of nail bed injuries. Edstrom 10 and
Daniller•• wrote of the continued frustration of the management of these injuries.
The INRO surgical nail splint was developed as an
alternative to the silicone sheet that has several disadvantages (Fig. 1, A and B). lt tears too readily when
From the Charlton Methodist Hospital; and the University of Texas,
Health Science Center, Dallas, Texas.
Received for publication June 9, 1986; accepted in revised form June
9, 1988.
Although none of the authors have received or will receive benefits
for personal or professional use from a commercial party related
directly or indirectly to the subject of this article, benefits have
been or will be received but are directed solely to a research fund,
foundation, educational institution or other non-profit organization
with which one or more of the authors are associated.
Reprint requests: E. Olayinka Ogunro, MD. 2727 Bolton Boone,
Suite 105, DeSoto, Texas 75115.
136
THE JOURNAL OF HAND SURGERY
sutured, it is difficult to seat finnly in the eponychial
fold because of its rubbery nature, and it does not possess the rigidity or the curves of the natural nail. Indeed
Zook 1 noted in his study that it "was difficult to maintain
in the nail fold during the healing phase, perhaps adversely affecting our results." The nail splint was therefore developed with qualities similar to the natural nail
for use when it is not available for reconstruction.
The artificial nail is made of polypropylene, which
provides the necessary rigidity. It is nontoxic, extremely
stable, nonreactive, and nonfibroblastic. The impact
strength affords considerable resistence to breakage and
protects the extremely sensitive nail bed from further
trauma during the healing phase.
When the splint is sutured in place it provides a finn
fixation for the nail bed and encourages the continuation
of Kligman's 12 vector forces distal to the eponychium
(Fig. 2, A). It molds the healing nail bed, which in
tum, acts as a template for the regenerating nail. The
newly fonned nail cells are forced to assume a more
horizontal and fiat course and adhere to the nail bed
(Fig. 2, B). The splint prevents granulation tissue ingrowth from the eponychium or the paronychium. Once
the nail has grown to approximately 4 mm or more and
Vol. 14A, No. 2, Part 1
March 1989
Surgical nail splint
23?
Fig. 1. A, Dorsal view. Drainage holes found to be necessary in prevention of hematoma formation .
B, Lateral view.
Dorsal Root-Shine
Dorsal Roof
Kligmans
Vector Force
0
Ventral Floor-Intermediate nail
Ventral Floor
Fig. 2. A, Kligman's vector force . A Kligman's vector force is the result of forces from the sulcus
and the eponychium acting on the regenerating nail to direct it distally and horizontally. Distal to
the eponychium the vector force becomes weaker because of the absence of the eponychial component. This is more evident in the presence of nail bed injury when the healing nail bed develops
its own vertical force. B, The nail splint enhances the effect of the eponychium distally and thereby
encourages the continued activation of the vector force distal to the eponychium . The splint also
exerts a direct compressive force on the healing nail bed . This force or molding factor is what
molds the injured nail bed. The combined effect of these encourage the regenerating nail to be flat
and adherent.
the nail bed has healed, normal growth appears to be
maintained when the splint is removed.
Operative procedure
Fractures of the distal phalanx are reduced. The nail
bed and matrix are repaired anatomically with No .
6-0 vicryl. The proximal sutures are applied as shown
in Fig. 2, B. using the horizontal drainage holes of the
splint, care being taken to avoid suturing the germinal
matrix. Traction on the suture will seat the splint firmly
in the sulcus (Fig. 2, B), distal sutures are then applied.
A dressing is applied for a week. The finger is evaluated
238
The Journal of
HAND SURGERY
Ogunro
!
/
~
I
·"i
.I
Fig. 3. (Case 12) A, Multiple avulsion injuries of nail bed and germinal matrix, with comminuted
fracture of the distal phalanx . B, At 9 months good result obtained (arrow).
Table I
Sire of injury
Case
2
3
4
5
6
7
Patie/11
Age
Sex
Digit
J. F.
18
M
Rtll
Rtlll
Rt IV
Rtll
Rt I
Lilli
Rt Ill
Rtl
RtV
Rt III
Lt I
Lt 111
Rtl
Ltl
Ltl
Rt Ill
Ltlll
Rt IV
Lt Ill
Rt I
C. W.
K. T.
K. H.
0. 0.
8
S. B.
A . D.
D. F.
9
10
C. H.
J. P.
II
]. s.
12
13
14
15
16
17
T. R.
J. S.
E. I.
Y. I.
J. G.
R. W.
M. C.
18
27
22
20
27
17
34
19
16
21
41
43
19
12
21
23
26
35
M
M
M
M
M
M
F
M
M
M
M
M
F
M
M
M
M
Palmar
fold
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
I
Dorsal
fold
Yes
Yes
No
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
No
I
Proximal
113
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
I
Middle
113
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
I
Distal
113
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
No
Yes
Yes
Yes
No
No
No
Yes
Yes
Yes
Yes
Vol. 14A, No. 2, Part I
March 1989
Surgical nail splint
weekly and use of the splint is stopped when the nail
bed has healed.
Material
There were 18 patients with 20 nail bed injuries; 16
males, with 18 fingernails, and 2 females, with 2 fingernails. The age range was 12 to 43 years, with a mean
of 24 years.
The injuries were categorized as in ZooJ(4 (Table I).
Patients seen initially with an intact nail plate were
excluded. In more than 90% of the cases injuries were
caused by industrial accidents.
Case no. 2 required a large bone graft to reconstruct
the distal and middle phalanx, which were completely
destroyed . In cases No . 3, 13, and 17, the nail splint
served additionally as a means of attachment for the
flap.
Results
Very strict criteria were used for grading the results .
The three grades wen~: good, fair, and poor. A nail
graded good must look like the corresponding uninjured
nail on the contralateral hand (Fig . 3, A and 8 ; Fig.
4, A through C). It must have regained its size, shape,
and smoothness and growth . Fair results were characterized by a nail that did not regain its original size,
shape, or smoothness; however, growth was normal.
~
~
Type of
injury
Associated
injuries
Date of
injury
Date of
surgery
Avulsion
Laceration
Laceration
Avulsion
Crush
Avulsion
Laceration
Avulsion
Stellate
Avulsion
Avulsion
Avulsion
Avulsion
Stellate
Avulsion
Avulsion
Stellate
Laceration
Avulsion
Avulsion
Fracture
Distal
Phalanges
Distal phalanx
Pulp loss
Distal phalanx
Distal phalanx
No
No
Distal phalanx
Distal phalanx
Distal phalanx
No
Distal phalanx
Pulp loss
Distal phalanx
Tuft fracture
Mallet finger
Distal phalanx
Distal phalanx
11/16/83
11/16/83
2 / 3/84
2 / 14/84
3/5/84
3 / 26 / 84
4 / l / 84
4 / 27 / 84
2 / 3 / 84
2/14/84
3/ 12 /84
3/ 26/84
4 / 3/84
4 / 30/84
514 184
514184
6/8/84
6/23/84
5114/84
11 / 17/84
3/2/85
6/27/84
6/23/84
5/14/84
11 / 17 / 84
3/ 2/85
3/ 22 / 85
3/21/85
3116185
3/18 185
416/85
8/9/85
4/16/85
4!6185
8/9/85
4/ 22/85
239
Nails that did not regenerate were placed in the poor
category.
One patient was lost to follow-up (Table 1) . Fifteen
out of 17 patients, or 17 out of 19 fingers demonstrated
good results. One patient with a fair result removed his
splint at 14 days. One patient with a poor result was
operated on 19 days after injury.
In one patient (case 2) an infected hematoma developed below the splint. This was treated by irrigation
with peroxide using a 22-gauge needle inserted beneath
the splint. Subsequent splints were modified with four
perforations to allow adequate drainage. There were no
allergic reactions, personal intolerance, or fracture of
a splint.
Discussion
Eighteen cases of severe nail bed injuries were studied using the splint as a nail substitute. None of these
patients were seen initially with their original nail or
portions thereof that could have been used as a splint.
It was noted that the splint functioned like the natural
nail and protected the highly tender and sensitive nail
bed from painful stimuli . It eliminated adherence of the
nail bed to the dressing, thus making a dressing change
more tolerable. It helped to reduce pain after avulsion
injuries of the nail plate and nail bed and prevented
bifid nail formation by the elimination of collagen tissue
Surgery
Repair/splint
Repair/ splint
Repair I splint
Repair I splint
Repair I splint
Repair/ splint
Repair/ splint
Repair/ splint
Repair / splint
Repair I splint
Repair I splint
Repair/ splint
Repair I splint
Repair I splint
Repair I splint
Repair I splint
Repair I splint
Repair/ splint
Repair I splint
Repair I splint
Associated
surgery
Follow-up
in momhs
9
9
9
ORIF / bone graft
Pedicle flap
ORIF I phalanx
18
II
9
7
16
8
2 lost
14
9
9
9
Pedicle flap
V-Y flap
5
8
8
4
6
12
Results
Good
Good
Good
Good
Good
Good
Good
Good
Good
Unknown
Poor
Fair
Good
Good
Good
Good
Good
Good
Good
Good
240
The Journal of
HAND SURGERY
Ogunro
y
Fig. 4. (Case 18) A, Extent of injury to the matrix and nail bed after removal of the coagulated
blood and granulation tissue at I week after injury. B, The medial portion of the matrix that was
too fragmented to repair was simply reduced and splinted. C, Final result obtained after complete
healing (arrow).
ingrowth from the nail fold into the nail bed or germinal
matrix . It helped to maintain the contour of nail bed
while it was healing and eliminated adhesion of eponychial fold to the nail bed thus encouraging the regeneration of germinal matrix . The regenerated nail was
not cornified. Cornification occurred I to 2 weeks after
exposure. The regenerated nail was thin, the cells migrated distally and horizontally from the vector force
created by the nail fold and the splint.
In acute nail bed injuries with associated fractures of
the nail plate that rendered it unsuitable for reconstruction, the FDA-approved splint was found to function
like the natural nail and served as a suitable substitute.
REFERENCES
I. Zook EG, Guy RJ, Russell RC. A study of nail bed
injuries : causes, treatment and prognosis. J HAND SuRa
1984;9A:247-52.
Vol. 14A, No . 2. Part I
March 1989
2. Zook EG, Van Beck AL, Russell RC, et al. Anatomy and physiology of the perionychium: a review of
the literature and anatomical study . J HAND SuRG 1980;
6:528-36.
3. Zook EG . The perionychium: anatomy, physiology, and
care of injuries. Clin Plast Surg 1981;8:21-31.
4 . Zook EG . Injuries of the fingernail. In: Green DP, ed .
Operative hand surgery. New York: Churchill Livingstone, 1982.
5. Flatt AE. Nailbed injuries . Br 1 Plast Surg 1955;8:3843 .
6. Flatt AE. Minor hand injuries. 1 Bone Joint Surg 1955;
378:117-25 .
Surgical nail splint
7. McCash CR . Full nail grafting . Br 1 Plast Surg 1956;
8:19-33 .
8. Shiller C . Nail replacement in fingertip injuries. Plast
Reconstr Surg 1957;19:521 -30.
9. Asbell TS, Kleinert HK, Putcha S, et al. The deformed
fingernail, a frequent result of failure to repair nail bed
injuries . 1 Trauma 1967;7:177-90.
10. Edstrom E. Correspondence News Letter. American Society of Surgery of the Hand . 1985-5 .
II . Dan iller Avron . Correspondence News Letter 1984-88 .
12. Kligman AM. Why do nails grow out instead of up?
Arch Dermatol 1961;84:313-5 .