INTRODUCTION
In the past, the results of primary tendon repair
in zone II were not very promising. This pushed
surgeons to consider delayed tendon grafting of
flexor digitorum profundus as the standard treatment.
Nowadays, with the improvement of surgical
techniques, suture materials, together with the
concept of early post-operative mobilization, the
superiority of primary repair for flexor tendon
injuries was established [1].
Several attempts have been made in order to
minimize adhesions and therefore improve the
results in terms of range of movement after flexor
tendon surgery using various pharmacologic agents
such as 5-fluorouracil, indomethacin and ibuprofen
[2-4].
Ozgenel and ETÖZ adopted the technique of
multiple injections; the first dose was given at the
time of tendon repair surgery and two additional
doses were given after 1 week and 2 weeks postoperative
[5].
Generally, HA has a positive effect on tendon
healing which is based on its anti-inflammatory
action, cell proliferation enhancement, and deposition
of collagen, besides the lubricating action
on the tendon sliding.
97
There are complex biological activities of HA,
such as: (A) Inhibition of Matrix Metalloproteinases
(MMPs) and the phagocytic activity of macrophages
and leukocytes; (B) Promoting the release of
prostaglandins and enhancing the normalization
of endogenous hyaluronan synthesis; (C) Being a
free radicals scavenger and stimulating proteoglycans
synthesis [6].
Actually, HA is actively secreted by the tendon
sheath being an important component of the synovial
fluid, which allows gliding of tendon smoothly,
and provides nutrition to tendon itself. Moreover,
it is also an important component of tendon structure,
and is present massively in extracellular space
[7].
The aim of our study is assessing the effect of
hyaluronate injection intra-and post-operative
within the fibro-osseus sheath in flexor tendon
repairs to minimize post-operative adhesions and
improve tendon gliding.
PATIENTS AND METHODS
This is a prospective randomized controlled
clinical trial, conducted at Ain Shams University
Hospitals on patients presenting from January to
September 2017 at Ain Shams University Hospitals.
This study was conducted on 40 digits for
patients presenting to Ain Shams Hospitals, presenting
with isolated zone II flexor tendon injuries
Scheduled for primary repair.
Patients were randomly split into 2 groups,
Group (A) where patients were subjected to hyaluronic
acid injection within the flexor tendon
sheath intra operative and in follow-up (20 patients)
those patients were selected of those who were
admitted to the department on Saturdays, Mondays,
and Wednesdays of the weeks of the trial, while
Group (B) where patients were subjected to placebo
(Normal Saline) injection within the flexor tendon
sheath intra-operative and in follow-ups. (20 patients)
those patients were selected of those who
were admitted to the department on Sundays, Tuesdays,
and Thursdays of the weeks of the trial.
The study was double-blinded for both the
patient and the physiotherapist.
All cases were operated by the same surgeon,
same technique; cruciate repair with epitendeous
sutures and introduced to the same rehabilitation
program.
All patients signed an informed consent form
beforehand. The personal data and medical information
of all patients were reported confidentially.
Inclusion criteria:
Ages of the participants were between 12-65
years with no gender restriction with recent Zone
2 flexor tendon injuries only.
Exclusion criteria:
Devascularized or devitalized soft tissue and
associated nerve injury affecting the range of
movement with associated bony fractures and
significant proximal tendinous end retraction beyond
zone III; also injuries occurring within 24
hours prior to repair with significant contamination
as well as severe hand injuries with skin loss
requiring coverage.
All patients were subjected to clinical examination
to determine the site of wound, whether the
wound is clean or contaminated, sharp or lacerated
wound. Also careful examination of the neurovascular
status of the hand: Evaluation of the sensory
and motor functions of median, ulnar and radial
nerves to exclude associated nerve injury, and
checking vascularity by capillary refill test as well
as peripheral pulsations. Tendon function was
evaluated with voluntary active movements of the
finger. Also; bone examination to exclude crepitus,
edema and deformities.
Routine pre-operative investigations were requested
for all patients, including complete blood
picture, coagulation profile, liver and kidney function
tests, fasting blood sugar, and ECG for those
above forty years old. X-ray hand antero-posterior
98 Vol. 44, No. 1 / The Use of Hyaluronate in Flexor Tendon Surgery in the Hand
and oblique views were done to exclude associated
bone fractures.
Operative technique:
Surgical repair was done either under general
or regional anesthesia (supra clavicular block).
Pneumatic tourniquet was used in all cases to
provide an avascular field during surgery.
The wound is thoroughly cleaned and irrigated
with saline solution. Pre-operative antibiotic prophylaxes
were administered to all cases.
All patient were operated upon in supine position
using hand surgery extension table with shoulder
abduction. Prophylactic antibiotics were administered
on induction in all cases based on our
hospital protocols. Then the hand and forearm were
draped and prepared for surgery.
The wound is examined, and then incisions are
planned that would allow access to proximal and
distal tendon ends.
The skin and subcutaneous fat are raised off of
the tendon sheath as a single thick layer.
The distal tendon end may often be delivered
by passive flexion of the DIP and PIP joints. The
proximal tendon end may be visible within the
fibro-osseous sheath. Retrieval of the proximal
end may be done using many techniques; we usually
give just one attempt to grasp the edge of the
tendon using a mosquito forceps, if grasped we
pull it distally and secure it in place with a fine
needle going transversely through the tendon and
adjacent soft tissue Fig. (1). If not accessible,
particularly if injury happened during hand flexion,
retrieval of the proximal end was aided by milking
of the forearm and hand across the course of the
tendon. If the tendon end is still not visible, the
wound is extended, and retrieval is achieved
through proximal palm incision, after which the
tendon is delivered to the trauma site again by the
aid of infantile nasogastric tube or a small Nelaton
catheter.
Neurovascular structures are identified and
checked for injuries and managed if found.
Surgical repair was performed using 4-stranded
cruciate repair using Prolene 4/0 because it is a
stronger tensile strength that resists rupture, and
repair site gapping, and allows early active mobilization
protocol Fig. (2).
To smooth and strengthen the site of tendon
repair, epitendinous sutures were taken by Prolene
6/0 sutures. Therefore epitendinous Sutures conEgypt,
J. Plast. Reconstr. Surg., January 2020 99
sidered an important adjunct to core tendon suture
[8] Fig. (3).
To adjust the tension after the repair, the hand
is left to show the normal cascade, we test the
gliding after the repair by flexing the repaired
tendon several times.
Hyaluronic acid injection at the repair site
intra-operative:
After the completion of the repair, a 18 Gauge
cannula is introduced into the digital sheath in both
proximal and distal ends of the repaired tendon
through which 2mls of Hyaluronic Acid (Hyalgan)
are injected after the release of tourniquet and
hemostasis and before skin closure Fig. (4).
Hyalgan is a viscous solution with a high molecular
weight (500,000-730,000) daltons. Fraction
of purified natural sodium hyaluronate in buffered
physiological sodium chloride, having a pH of 6.8-
7.5.
Post-operative follow-up and injection of hyaluronic
acid:
We started physiotherapy in all patients on the
3rd day after surgery-in case of injury to neurovascular
bundle, rehabilitation was started on the 10th
post-operative day. Post-operative antibiotics,
analgesics and anti-edematous measures are prescribed
for all cases.
Weekly visits are scheduled for the patients,
2mls of Hyaluronic acid are injected after one
week post-operative and another 2mls are injected
after two weeks post-operative.
The injection site is prepared with Alcohol
swab, then the tip of the 27 Gauge Needle is inserted
proximally and distally at the site of the
injury in the finger and angled approximately 45º
both proximally and distally.
The tip is advanced blindly through skin, fibroosseus
sheath till it hits the tendon, then the tip is
slowly withdrawn 1-2mm indicating that the needle
is within the flexor tendon sheath. This injection
should not require any force in a similar technique
like injecting steroids in the flexor sheath as in
cases of trigger finger treatment [9].
Then 2mls of Hyaluronic Acid are injected into
the flexor tendon sheath, 1ml proximal and 1ml
distal to the repair site.
In the control group, the same procedure was
performed using physiological saline.
Assessment: After 12 weeks, we used a goniometer
to assess the range of motion of MCP, PIP
and DIP joints of each finger Fig. (5).
The passive and active range of motion values
for the three joints in each finger were summed
up as the total range of passive motion (TPM) and
the total range of active motion (TAM).
The long-term follow-up for the final active
motion of each operated finger was done using the
modified strickland grading system. The active
motion value was calculated by subtracting the
extension deficit of the involved joints from the
maximal possible flexion. Results were classified
as; excellent if >131º, good if 88-131º, fair if 44-
87º and poor if <44º.
Rehabilitation and post-operative care;
Program of early active mobilization (active
place and hold), this program was divided into
four phases as follows [10]:
In the post-operative phase I which takes from
1-4 weeks starting from 1 day post-operatively and
continuing to 4 weeks where active place-hold (we
passively place the digits into flexion and then
instruct the patient to actively maintain the position
with gentle muscle contraction). Where composite
and straight fist exercises are performed Fig. (7).
Tenodesis exercises involved active digital
extension with the wrist flexed. FDS and FDP
blocking exercises are performed for uninvolved
digits. Passive flexion and active extension to
Proximal Inter Phalangeal (PIP) and Distal Inter
Phalangeal (DIP) joints till the limit of the splint.
Phase II from 4-6 weeks where we continue
with dorsal blocking splint and continue passive
flexion active extension to PIP and DIP joints in
addition to beginning place and hold active hook
fist exercises as well as active tenodesis exercises,
with composite, straight, hook, and tabletop fists.
Then phase III from 6-8 weeks where the dorsal
blocking splint is removed and active tenodesis
exercises are continued in addition to active tendon
glide exercises with gentle blocking exercises to
FDS and FDP to start at 6 weeks for the involved
digit Fig. (8). Also isometric pinch and grip exercises
are performed.
Finally phase IV in 8-12 weeks where active
and resistive exercises are continued (hand grip
and pinch against resistance) [11].
Fig. (6): TPM in both Groups A & B.
257.0
256.5
256.0
255.5
255.0
254.5
254.0
253.5
253.0
Group A Group B
257.00
254.50
TPM
100 Vol. 44, No. 1 / The Use of Hyaluronate in Flexor Tendon Surgery in the Hand
Fig. (5): Measurement of the range of motion using goniomete.
Fig. (1): Maintaining the tendon position after retrieval of
proximal and distal ends.
Fig. (3): Epitendineous sutures using Prolene 6-0.
Fig. (4): Injection of hyaluronic acid at the repair site.
(A)
(B)
Fig. (2): The cruciate technique of tendon repair.
Cruciate
Egypt, J. Plast. Reconstr. Surg., January 2020 101
RESULTS
The socio-demographic data of Group A & B
show that there was no statistically significant
difference found between Group A and Group B
regarding sex, age causative instrument and hand
while there was statistically significant difference
found between them regarding finger. As shown
in (Table 2).
There is an increase in the Total Passive Movement
(TPM) in the study group which was treated
by hyaluronic acid injection. Fig. (6) and (Table 3).
As shown in (Table 4) and with clinical observation,
the range of motion is better in the study
Group (A) after treatment with HA injection. Figs.
(7,8).
The statistical analysis of the range of motion
over the 3 joints MCP, PIP and DIP reveals significant
improvement in the active PIP and DIP in
the study Group (A) which was treated with the
injection of HA. While there was a decline in the
active MCP in the same group compared to the
control group Figs. (9,10) (Table 5).
Fig. (7): Stages of the study. (A) Represents the injury during
pre-operative examination, (B) Shows the surgical
technique of repair, intraoperative, while (C) Shows
the motion of the treated finger after 4 weeks of
operation.
Fig. (8): Another case treated with HA injection. (A) Shows
the tendon injury with obvious hematoma at the site
of injury, (B) Shows results after 5 weeks postoperative,
(C) Shows the result after 3 months.
(A)
(B)
(C)
(A)
(B)
(C)
The statistical analysis show there is an increase
of the total active motion of the study
Group (A) compared to the control Group (B)
Fig. (11), (Table 6).
The analysis of the rate and type of complications
reveals that the rate of injection is higher
(10%) in the study Group (A), for (5%) in the
control Group (B). However, no cases were complicated
by stiffness in the study Group (A),
compared to 20% in control Group (B) Fig. (12),
(Table 7).
The data representation show an increase in the
adjust strickland score in Group A, than in Group
B; which significance that there is an improvement
with the treatment of flexor tendons with hypo
acid, represented by better adjusted strickland
scores and grades Figs. (13,14), (Table 8).
102 Vol. 44, No. 1 / The Use of Hyaluronate in Flexor Tendon Surgery in the Hand
Fig. (9): Active range of motion at MCP of both Groups A & B.
85
84
83
82
81
80
Group A Group B
81.50
84.50
Active MCP
74
72
70
68
66
64
62
Group A Group B
72.25
66.00
Active DIP
Fig. (10): Active range of motion at DIP in both groups.
Fig. (11): TAM comparison between Group A & B.
228
226
224
222
220
218
216
214
212
Group A Group B
227.50
218.25
TAM
Fig. (13): Adjusted strickland score for both Groups A & B.
84
82
80
78
76
74
72
Group A Group B
82.75
76.00
Modified strickland
Fig. (14): A.S grade for both or A & B.
90
80
70
60
50
40
30
20
10
0
Excellent Good
%
Modified strickland grade
85
65
15
35
Group A Group B
Table (1): Strickland's evaluation systems.
Score
Excellent
Good
Fair
Poor
Original Strickland
%
85-100
70-84
50-69
<50
75-100
50-74
24-49
0-24
Adjusted Strickland
%
90
80
70
60
50
40
30
20
10
0
%
No
complications
Stiffness
90
75
10
5
0
20
Infection
Group A Group B
Fig. (12): Complications in both Groups A & B.
Complications
Egypt, J. Plast. Reconstr. Surg., January 2020 103
Table (2): Comparison between Group A and Group B regarding
socio-demographic data.
Socio-demographic
data
Sex:
Females
Males
Age:
Mean ± SD
Range
Causative
instrument:
Electric saw
Glass
Knife
Metal coil
Hand:
Left
Right
Finger:
Index
Little
Middle
Ring
Group A
No.=20
3 (15.0%)
17 (85.0%)
28.95±10.85
17-44
2 (10.0%)
9 (45.0%)
6 (30.0%)
3 (15.0%)
8 (40.0%)
12 (60.0%)
0 (0.0%)
6 (30.0%)
3 (15.0%)
11 (55.0%)
Group B
No.=20
7 (35.0%)
13 (65.0%)
27.95±10.93
15-41
0 (0.0%)
10 (50.0%)
10 (50.0%)
0 (0.0%)
13 (65.0%)
7 (35.0%)
3 (15.0%)
0 (0.0%)
6 (30.0%)
11 (55.0%)
Test
value
2.133*
–0.290•
6.053*
2.506*
10.000*
pvalue
0.144
0.773
0.109
0.113
0.019
Sig.
NS
NS
NS
NS
S
•
*
HS
: Independent t-test.
: Chi-square test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
Table (3): Comparison between TPM of the injured hand in
both Groups A & B.
TPM normal
Mean ± SD
Range
Group A
No.=20
257.00±15.59
230-270
Group B
No.=20
254.50±23.28
210-270
Test
value•
–0.399
pvalue
0.692
Sig.
NS
•
HS
: Independent t-test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
Table (4): Comparison between range of movement in both
Groups A & B.
Injured hand
Active MCP:
Mean ± SD
Range
Active PIP:
Mean ± SD
Range
Active DIP:
Mean ± SD
Range
Group A
No.=20
81.50±3.66
80-90
73.75±15.03
40-85
72.25±6.78
60-80
Group B
No.=20
84.50±5.10
80-90
67.75±15.34
40-80
66.00±9.54
50-75
Test
value•
2.135
–1.249
–2.388
•
HS
: Independent t-test.
: Highly Significant.
pvalue
0.039
0.219
0.022
Sig.
S
NS
S
S
NS
: Significant.
: Non Significant.
Table (5): Comparison between TAM of both Groups A & B.
TAM
injured hand
Mean ± SD
Range
Group A
No.=20
227.50±21.12
180-245
Group B
No.=20
218.25±27.21
170-245
Test
value•
–1.201
pvalue
0.237
Sig.
NS
•
HS
: Independent t-test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
Table (6): Comparison between the rates of complication in
both Groups A & B.
Complications
No complications
Infection
Stiffness
No.
18
2
0
%
90.0
10.0
0.0
Sig.
NS
*
HS
Group A
75.0
5.0
20.0
%
Group B
No.
15
1
4
Test
value*
4.606
pvalue
0.099
: Chi-square test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
Table (7): Comparison between the adjusted Strickland score
for Groups A & B.
Modified
Strickland
Mean ± SD
Range
Group A
No.=20
82.75±11.85
57-94
Group B
No.=20
76.00±14.04
51-88
Test
value•
–1.643
pvalue
0.109
Sig.
NS
•
HS
: Independent t-test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
Table (8): Comparison between A.S grade for both Groups A
& B.
Modified
Strickland
Grade
Excellent
Good
No.
17
3
%
85.0
15.0
Sig.
NS
*
HS
Group A
65.0
35.0
%
Group B
No.
13
7
Test
value*
2.133
pvalue
0.144
: Chi-square test.
: Highly Significant.
S
NS
: Significant.
: Non Significant.
DISCUSSION
The aim of this study is to compare the effects
of repeated injections of hyalorinate versus placebo
injection (normal saline) on the functional outcome
following the primary repair of zone II flexor
tendon injury.
The first study aimed to assess the effect of
HA injection on prevention of adhesions in flexor
tendon surgery was performed by Lars Hagberg in
which he demonstrated no significant benefit of
hyalorinate injection in single-dose intraoperatively
during the flexor tendon repair, as it is rapidly
eliminated from the tendon sheath [12].
Güzin Ozgenel and Abdullah ETÖZ adopted
the technique of multiple injections; the first dose
was given at the time of tendon repair during
surgery and two additional doses were given at
one-week intervals. In our study we decided to
inject HA repetitively to provide maintenance of
sufficient doses to reduce post-operative adhesions
and increase the range of motion [5].
Ozgenel and ETÖZ also introduced a 23G catheter
with its tip placed near the FDP repair site and
threaded subcutaneously, to exit the skin at A1
pulley level, the catheter was then fixed to the skin
at the exit site [5].
We believe that this technique could be unsafe
and impractical, for fear of compromising the repair
due to the high possibility of infection; even with
the use of antibiotics. In our study we injected the
intra-operative dose using a syringe not a preinserted
cannula 1ml proximal and 1ml distal to
the repair site, then we closed the skin, the later
injections were performed by the same technique
used to inject corticosteroids in trigger finger;
which we thought is safer for the patients by protecting
the repair site.
In their study; Güzin Ozgenel and Abdullah
ETÖZ adopted the modified Kessler technique
using Prolene 4/0 sutures followed by epitendinous
running suture using Prolene 6/0. We preferred the
cruciate repair since we started using it in our
department in 2013 as it provided stronger tenorraphy
with less gaping and more ability to withstand
early active mobilization with massive reduction
of the rupture rate [5].
In Conclusion: The study we have performed
revealed that the repeated injection of hyaluronic
acid as an adjunct treatment in the flexor tendon
repair surgeries was indeed successful in reducing
the post-operative adhesions, improving tendon
gliding and tendon healing which is based on
properties of HA as its anti-inflammatory action,
cell proliferation enhancement, and increase collagen
deposition, besides the lubricating action on
the sliding surface of the tendon.
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