Keywords
chronic limb-threatening ischemia - total contact cast - free flap - diabetic foot
ulcer
Introduction
With the increasing prevalence of diabetes worldwide, the number of patients with
chronic limb-threatening ischemia (CLTI) is increasing.[1]
[2] CLTI is considered to pose a risk of lower extremity amputation owing to ischemia,
infection, and nerve damage. Its diagnosis requires that the patient has one of the
following symptoms: (1) pain at rest confirmed by hemodynamic testing (Wound Ischemia
Foot Infection [WIfI] grade 3 ischemia); (2) a diabetic ulcer or leg ulcer that lasts
for more than 2 weeks; or (3) gangrene of the lower legs or feet.[3]
Patients with CLTI are prone to foot ulcers and face a constant risk of lower limb
amputation.[4] In cases where there is extensive bone exposure or weight-bearing areas, free flap
reconstruction is performed.[5]
[6]
[7]
[8]
[9]
[10] As this is a reconstruction of the foot, determining the optimal time to resume
walking can be challenging. Early walking training can lead to complications such
as wound dehiscence and prolonged bed rest. When wound dehiscence occurs on the sole
of the foot of a patient with CLTI, walking with full weight-bearing must be prohibited.
Patients with CLTI have poor wound healing owing to diabetes, are prone to infection,
and often require prolonged treatment. This means that the period of walking prohibition
is long, and muscle weakness may occur. These complications can be addressed using
a total contact cast (TCC), which is an effective treatment for diabetic plantar ulcers,
immobilizing the foot and redistributing weight away from the ulcer area.[11] When weight is applied using a TCC, the pressure on the sole and heel can be significantly
reduced. In addition, compared with other removable orthotics, a TCC is the most effective
in the healing of diabetic foot ulcers.[12] For this reason, TCC is positioned as the gold standard treatment for diabetic foot
ulcers.[13]
[14]
The application of a TCC may enable early initiation of full weight-bearing in cases
of CLTI reconstructed with free flaps, but the increase in complications associated
with early weight-bearing and the use of a TCC is unknown. In this study, we aimed
to investigate whether complications of the initiation of full weight-bearing were
more common with the use of a TCC than those without and whether complications occurred
owing to the fitting of a TCC.
Methods
We retrospectively investigated patients with CLTI and plantar ulcers who underwent
free flap reconstruction between 2006 and 2023. This study was approved by the Ethics
Committee of Tokushima University Hospital (approval number: 3943-2). Consent was
obtained from the participants for the publication of their case details. We analyzed
the postoperative complications and the number of days until weight-bearing in five
cases with postoperative TCC (TCC group) and seven cases without TCC (non-TCC group).
Since 2019, TCCs have been indicated for all cases of plantar ulcers reconstructed
with free flaps in our institution. In the TCC group, by wearing the TCC, the load
was distributed over the entire foot. Therefore, we thought that wound dissolution
would be less likely to occur and we started loading earlier than that in the non-TCC
group. Full weight-bearing was initiated approximately 2 weeks after surgery with
the TCC applied. To reduce the risk of developing pressure ulcers due to the TCC,
sponges were applied to bony protrusions such as the medial malleolus, lateral malleolus,
heel, and tibia, and a cotton bandage was wrapped around the foot and lower leg. The
ankle joint was fixed at approximately 90 degrees ([Fig. 1]). In the TCC group, the timing of full weight loading was determined by the surgeon
on the basis of the condition of the wound approximately 2 weeks later. The non-TCC
group was determined on the basis of the condition of the wound approximately 4 weeks
after surgery. In the non-TCC group, if no problems with the wound were detected,
loading with a gauze dressing was started 4 weeks after surgery. In the TCC group,
the TCC was removed after 1 week, and the skin flap was confirmed. Care was taken
to avoid applying excessive pressure by covering the bypass vessels and the vascular
anastomoses of the flap with a sponge. The color of the flap can be evaluated through
the opening at the toe of the TCC in many cases. In cases of a heel flap, a hole can
be made in the cast above the flap for such observation. Similarly, in the case of
bypass vessels, a hole can be made in the desired area to evaluate the blood flow.
The TCC was replaced once a week and applied continuously until approximately 1 month
postoperatively. To closely examine osteomyelitis, an MRI examination was performed
preoperatively. Contrast-enhanced computed tomography and ultrasound examinations
were performed preoperatively in all cases. In addition, preoperative angiography
was performed for cases in which revascularization was performed. We also compared
flap size, hemodialysis, skin perfusion pressure (SPP), incidence of flap necrosis,
incidence of wound dissection, and presence of ulcers at discharge between the two
groups. Small ulcers that healed conservatively were not considered ulcers. We also
investigated the presence of diabetes, WIfI stage,[15] Global Anatomic Staging System stage,[4] and the location of foot ulcers.
Fig. 1 (A) A case in which an anterolateral thigh flap was transplanted to the base of the
big toe. (B) A cylindrical bandage was applied and the malleolus and midline were protected with
a sponge. (C) Wrapping in a patting bandage. (D) Fixation using cast bandage.
Statistical analysis was performed using Excel-based statistics, Mann–Whitney tests,
and chi-square tests. Statistical significance was set at p < 0.05.
Results
In the non-TCC group, the preoperative site of the foot ulcer was the plantar side
in two cases, the forefoot in three cases, the heel in one case, and the lateral side
of the foot in one case. In the TCC group, one ulcer involved the plantar side, three
in the forefoot area, and one in the medial foot area. Transplanted flaps were present
in the loading areas in all patients. All ulcers were stage 4 according to the WIfI
classification ([Table 1]), and all patients with CLTI had diabetes mellitus. The mean glycohemoglobin level
was 7.58 ± 2.02% in the non-TCC group and 9.13 ± 3.39% in the TCC group (p = 0.195). Four (57.1%) patients in the non-TCC group and two (40%) in the TCC group
had hypertension. Additionally, three (42.9%) patients in the non-TCC group and two
(40%) in the TCC group underwent hemodialysis (p = 0.921). Four (57.1%) patients in the non-TCC group and four (80%) in the TCC group
had a history of smoking. The average body mass index was 22.84 ± 7.32 kg/m2 in the non-TCC group and 25.25 ± 1.58 kg/m2 in the TCC group (p = 0.315). The mean SPP was 50.6 ± 15.3 mm Hg in the TCC group and 67.8 ± 15.6 mm
Hg in the non-TCC group (p = 0.082). In the non-TCC group, foot ulcers occurred on the forefoot in two cases,
midfoot in three cases, and heel in two cases. In the TCC group, foot ulcers occurred
in the forefoot section of the foot in four cases, midfoot in one case, and heel in
zero cases (p = 0.175). In the non-TCC group, the Global Limb Anatomic Staging System stage was
not applicable in one case, I in three cases, II in one case, and III in two cases
(p = 0.318; [Table 2]).
Table 1
Wound Ischemia Foot Infection grade
|
WIfI grade
|
Total
n = 12
|
TCC group
n = 5
|
non-TCC group
n = 7
|
|
Wound 0
1
2
3
|
0
0
0
12
|
0
0
0
5
|
0
0
0
7
|
|
Ischemia 0
1
2
3
|
7
4
0
1
|
3
2
0
0
|
4
2
0
1
|
|
Foot infection 0
1
2
3
|
0
1
6
5
|
0
0
3
2
|
0
1
3
3
|
Abbreviations: TCC, total contact cast; WIfI, Wound Ischemia Foot Infection.
Table 2
Clinical characteristics of patients with chronic limb-threatening ischemia
|
Parameter
|
Total
(n = 12)
|
Non-TCC group
(n = 7)
|
TCC group
(n = 5)
|
p-value
|
|
Mean age ± SD, years(range)
|
58.3 ± 6.9
(49–69)
|
59.9 ± 6.9
(52–69)
|
56.2 ± 7.2
(49–67)
|
0.565
|
|
Sex, N
|
|
0.217
|
|
Men
Women
|
11
1
|
7
0
|
4
1
|
|
Diabetes, N (%)
Mean HbA1c ± SD, %(range)
|
12 (100)
|
7 (100)
7.58 ± 2.02
(5.6–11.1)
|
5 (100)
9.13 ± 3.39
(5.7–13.1)
|
0.195
|
|
Hypertension, N (%)
|
6 (50)
|
4 (57.1)
|
2 (40)
|
0.558
|
|
Hemodialysis, N (%)
|
5 (41.7)
|
3 (42.9)
|
2 (40)
|
0.921
|
|
Smoking, N (%)
|
8 (66.7)
|
4 (57.1)
|
4 (80)
|
0.408
|
|
Mean body mass index ± SD, kg/m2 (range)
|
23.72 ± 5.87 (15.9–36.2)
|
22.84 ± 7.32
(15.9–36.2)
|
25.25 ± 1.58
(23.2–27.0)
|
0.315
|
|
Skin perfusion pressure ± SD, mm Hg (range)
|
57.75 ± 17.18 (29–81)
|
50.57 ± 15.30
(29–75)
|
67.80 ± 15.64
(29–81)
|
0.082
|
|
Site of foot ulcer
|
|
0.175
|
|
Foremost part
Middle foot
Heel
|
6
4
2
|
2
3
2
|
4
1
0
|
|
GLASS stage NA
|
4
|
1
|
3
|
0.318
|
|
I
II
III
|
4
2
2
|
3
1
2
|
1
1
0
|
Abbreviations: GLASS, Global Limb Anatomic Staging System; HbA1c, glycohemoglobin;
NA, not applicable; SD, standard deviation; TCC, total contact cast.
The average flap size was 149 ± 69.1 cm2 in the non-TCC group and 95.6 ± 73.1 cm2 in the TCC group (p = 0.268). Regarding flaps, in the non-TCC group, six cases were reconstructed with
the latissimus dorsi (LD) and one case with the anterolateral thigh (ALT). In the
TCC group, the flaps used for reconstruction were the LD in two cases, ALT in two
cases, and the scapula in one case. Regarding recipient vessels, the anterior tibial
artery was selected in 11 cases, the posterior tibial artery in 1 case, and bypass
grafting in 1 case ([Table 3]). Partial flap necrosis was detected in three (42.9%) patients in the non-TCC group;
however, it was not found in any patients in the TCC group (p = 0.091). The postoperative wound dehiscence rate was 42.9% (3/7) and 20% (1/5) in
the non-TCC and TCC groups, respectively (p = 0.408). At the time of discharge, ulcers were detected in 28.6% (2/7) and 20% (1/5)
of the patients in the non-TCC and TCC groups, respectively (p = 0.735; [Table 4]). The postoperative time to the initiation of full weight-bearing on the affected
limb was 52.3 ± 33.2 days in the non-TCC group and 19.8 ± 3.56 in the TCC group (p = 0.105; [Table 5]). After discharge, the mean follow-up period was 78.1 months for the non-TCC group
and 15 months for the TCC group. In the non-TCC group, four patients had ulcer recurrence
in the follow-up period, and three underwent additional surgery. In the TCC group,
one patient had a recurrence, and none of the patients underwent additional surgery.
Table 3
Surgical technique
|
Parameter
|
Total
(n = 12)
|
Non-TCC group
(n = 7)
|
TCC group
(n = 5)
|
p-value
|
|
Mean flap size ± SD, cm2 (range)
|
126.8 ± 72.8
(28–270)
|
149 ± 69.1
(66–270)
|
95.6 ± 73.1
(28–216)
|
0.268
|
|
Type of flap
|
|
0.085
|
|
LD
ALT
Scapula
|
8
3
1
|
6
1
|
2
2
1
|
|
Recipient vessel
|
|
0.206
|
|
ATA
PTA
Bypass graft
|
11
1
1
|
7
1
0
|
4
0
1
|
Abbreviation: ALT, anterolateral thigh; ATA, anterior tibial artery; LD, latissimus
dorsi; NA, not applicable; PTA, posterior tibial artery.
Table 4
Incidence of postoperative complications
|
Complications
|
Non-TCC group (%)
|
TCC group (%)
|
p-value
|
|
Flap partial necrosis
|
3/7 (42.9)
|
0/5 (0)
|
0.091
|
|
Wound dehiscence
|
3/7 (42.9)
|
1/5 (20%)
|
0.408
|
|
Ulcer remains at discharge
|
2/7 (28.6)
|
1/5 (20)
|
0.735
|
Abbreviation: TCC, total contact cast.
Table 5
Comparison of this study with previous reports
|
Study
|
Days until postoperative full weight-bearing
(range)
|
Mean size of flap, cm2 (range)
|
Site of ulcer
|
Postoperative complications
|
Pathology
|
|
TCC group (our study)
N = 5
|
19.8 days
(17–25)
|
95.6 (28–216)
|
Heel: 0
Middle foot: 1
Foremost part: 4
|
Partial necrosis: 0
Wound dehiscence: 1
|
CLTI: 5
|
|
Non-TCC group (our study)
N = 8
|
52.3 days
(24–109)
|
149 (66–270)
|
Heel: 2
Middle foot: 3
Foremost part: 2
|
Partial necrosis: 3
Wound dehiscence: 1
|
CLTI: 5
|
|
Santanelli et al[6]
N = 14
|
1 month: 7
2 months: 1(excluding fracture cases)
|
73.5 (28–192)
|
Heel: 11
Middle foot: 3
|
No data
|
Trauma: 7
Tumor: 7
|
|
Han et al[7]
N = 26
|
6 weeks
|
133.2 (22–486)
|
Heel: 11
Middle foot: 6
Foremost part: 6
Whole plantar: 3
|
Partial necrosis and delayed healing: 4
|
Trauma: 25
Other: 1
|
|
Abdelfattah et al[8]
N = 18
|
4 weeks
(excluding fracture cases)
|
115.5 (28–240)
|
Heel: 11
Middle foot: 5
Foremost part: 2
|
Partial necrosis: 1
Wound dehiscence: 1
|
CLTI: 4
Trauma: 10
Tumor: 3
Scar: 1
|
|
Lee et al[9]
N = 33
|
No data
|
No data
|
Heel: 14
Middle foot: 13
Foremost part: 5
Ankle: 6
|
Partial necrosis: 4
Total necrosis: 3
Wound dehiscence: 6
|
CLTI: 33
|
Abbreviations: CLTI, chronic limb-threatening ischemia; TCC, total contact cast.
Discussion
Patients with CLTI often have many complications and are unable to walk for an extended
time because of plantar scars, even before surgery. Therefore, extended bed rest following
surgery can lead to a decline in muscle strength, which may affect walking ability.
Thus, walking should be resumed as soon as possible. In this study, the group that
used TCC postoperatively had a shorter weighted onset period than the group that did
not. These findings suggest that TCC is effective in preventing muscle weakness in
patients who have undergone free flap foot surgery. Several reports of cases in which
the sole was reconstructed using a free flap have noted that full weight-bearing occurred
1 month after the surgery ([Table 5]).[6]
[7]
[8]
[9]
A concern regarding the use of TCC in patients with CLTI is the increased complications
of pressure ulcers and infection.[16] In-line with this, an erosion of approximately 1 cm was observed in one patient;
however, it resolved conservatively, and there were no major complications.
Tickner et al recommended not using a TCC unless the systolic ankle pressure was ≥80 mm
Hg.[13] In the current study, we used the SPP test and found that SPP and ankle pressure
were similar. However, SPP fluctuates during dialysis, and the value may not be reliable
in hemodialysis patients.[17] Although some of our patients had an SPP of 29 mm Hg, no complications occurred.
Therefore, sponges to prevent pressure ulcers may be effective. In addition, replacing
the TCC and checking the wound after 1 week was effective in preventing major complications.
A limitation of this study was the small number of patients, which may explain why
no significant differences were observed. However, there were almost no TCC-related
complications in the TCC group, and the results of this study showed that when using
a TCC, the wound area was protected, and no problems arose when the full weight was
applied 2 weeks after free flap reconstruction surgery. The inclusion of more patients
in the study is unlikely to alter the present finding of fewer complications in the
TCC group. Even without TCCs, complications may not increase if weight-bearing is
started early, approximately 2 weeks after surgery. In this study, we could not deny
this possibility. Another limitation of this study is that Asians tend to have smaller
body frames and less load pressure compared with Westerners; thus, these results may
not be generalizable to patients with large weight-bearing. We also believe that it
is important to analyze each part of the foot in foot reconstruction, but the number
of cases in this study was small and it was not possible to separate the results by
part. We consider this study to be an exploratory study, and additional research is
necessary in the future.
Patients with CLTI have a longer non-loading period, which increases patient stress.
This problem can be alleviated by using a TCC postoperatively. Postoperative use of
a TCC after free flap foot reconstruction may lead to an earlier hospital discharge
and allow for early weight-bearing of the affected limb after surgery. In the future,
randomized studies comparing the TCC and non-TCC groups should be conducted.
Conclusion
TCCs were indicated in cases where plantar ulcers were reconstructed using free flaps
and were useful in shortening the non-loading period without increasing the risk of
postoperative complications. Further research is needed to confirm this conclusion.
