ORIGINAL ARTICLE

Total Management of Diabetic Foot Ulcerations – KobeClassification as a New Classification of Diabetic Foot Wounds
Hiroto Terashi,1 Ikuro Kitano2 and Yoriko Tsuji2

Department of Plastic Surgery, Graduate School of Medicine, Kobe University, Kobe, Japan
2
Wound Healing Center, Shin-Suma General Hospital, Kobe, Japan

1(Received for publication on September 13, 2010)(Revised for publication on October 27, 2010)(Accepted for publication on November 25, 2010)

Treatment must be conducted after proper assessment of diabetic foot wounds. This implies
appropriate foot care and the use of proper footwear from the perspectives of prophylaxis andwalking. Diabetic foot wounds have some wound impairment factors, including peripheral neuropathy (PN), peripheral arterial disease (PAD), and infection; such wounds comprise combinations of these lesions. An additional goal besides wound healing is gait salvage. Here, we
propose a simple new four-level classification of diabetic foot ulcerations, which we havetermed the Kobe classification, in order to assess the wounds more easily and treat them systematically; the classification is as follows: Type I, mainly PN; Type II, mainly PAD; Type III,mainly infection; Type IV, PN+PAD+infection. (Keio J Med 60 (1) : 17－21, March 2011)

Keywords: diabetic foot, peripheral neuropathy, peripheral arterial disease, infection
Introduction

grade the wound appropriately. The University of Texas
wound classification system assesses ulcer depth, thepresence of wound infection, and the presence of clinicalsigns of lower extremity ischemia. This system uses amatrix with grade on the horizontal axis and stage on thevertical axis. It is more descriptive and shows a greater
association with increased risk of amputation and prediction of ulcer healing than the Wagner system does; 5however, in the University of Texas system, wounds areclassified into 16 categories, and it is difficult to understand them and to deal them with.
Type 2 diabetes is a growing epidemic in Asia, characterized by rapid rates of increase over a short period andonset at a relatively young age and low body mass index. 6 Kadowaki, et al. reported that early insulin response was an independent predictor for diabetes. 7 In
Japanese men with normal glucose tolerance, even asmall increase in BMI produced a decrease in beta cellfunction disproportionate to that in insulin sensitivity, 8
indicating that there are inherent differences between
Asian and Caucasian populations. Furthermore, Asia

The incidence of diabetic foot disease is on the risethroughout the world.1 Improving the management of diabetic foot disease is a mission for the plastic surgeon in
Japan and other Asian countries because there are nospecialist podiatrists in these countries. To promote thetotal management and proper treatment of this condition,a classification system for wounds of the diabetic foot isneeded. Currently, there are three main classificationsystems worldwide. The first is the Wagner classification
system, which is the most widely accepted and universally used grading system.2 The second is the depth-ischemia classification,3 a modification of the Wagner system. The third is the University of Texas wound classification system.4 Because the Wagner classification system is basically anatomical, with gradations of superficial ulcer, deep ulcer, abscess osteitis, gangrene of thefoot, and gangrene of the entire foot, it is not always
suitable for assessing wound therapy. The depth-ischemia classification is complicated and it is difficult toPresented at the 1774th Meeting of The Keio Medical Society in Tokyo, July 10, 2010.
Reprint requests to: Hiroto Terashi, MD, PhD, Department of Plastic Surgery, Graduate School of Medicine, Kobe University, Kusunoki-cho 7-5-2, Chuo-ku,
Kobe 650-0017, Japan, E-mail: terashi@med.kobe-u.ac.jp
Copyright © 2011 by The Keio Journal of Medicine
17Terashi H, et al: Total Management of Diabetic Foot Wounds in Asia

18

Table 1 Kobe classification and treatment for each type of woundType

Pathophysiology

Main treatment

I

Mainly PN

Pressure reliefII

Mainly PAD

Revascularization

III

Mainly infection

Early debridement

PN+PAD+infection

Revascularization and debridement on a case-by-case basis

IVdoes not have the distinct discipline of podiatric medicine, such as exists in Europe and America. The podiatrist is a special medical doctor who serves the most important role for mechanical and metabolic conditions affecting the foot. Therefore, we need to establish a newclassification system, such as the Kobe classification, fordiabetic foot wounds that is more appropriate for Asianpeople because of the differences between Asian andCaucasian populations.
Materials, Methods, and Results
Three etiologies of diabetic foot wounds are considered: peripheral neuropathy (PN), peripheral arterial disease (PAD), and infection. The pathophysiological combination of this triad leads to many wounds.9
We treated and followed up 266 limbs with diabetic ulcers at Shin-Suma general hospital from November 2002
to August 2008. We propose a new simple classificationof diabetic foot ulcerations, the Kobe classification, inorder to assess wounds more easily and treat them systematically. The system classifies wounds into fourtypes:
Type I, mainly composed of PN, 49 limbs
Type II, mainly composed of PAD, 180 limbs
Type III, mainly composed of infection, 16 limbs
Type IV, all three combined (PN+PAD+infection), 21limbs.
Table 1 shows the new classification and the main
treatment for each wound type.
Type I
Type 1 wounds mainly result from PN. There are three
type of PN, i.e., autonomic neuropathy, motor neuropathy, and sensory neuropathy.1 0 Autonomic neuropathy
can result in the opening of arteriovenous shunts on theplantar surface of the foot. The shunts result in a redirection of blood flow away from the nutrient capillaries andthe skin and can also cause the loss of sweating. Poor
sweating can cause the foot to become dry and cracked.
Recently, it was established that the sweat from eccrine
glands in the undiseased state contains much epidermal
growth factor (EGF) and that the epithelium of the eccrine ducts contains epidermal growth factor receptors

Fig. 1 The patient is a 45-year-old woman who had had diabetes
mellitus for 5 years.
(A) Ulceration beneath callus on the right sole due to Charcot foot.
(B) Lateral view.
(C) Footwear for pressure relief.

(EGFR). 11 The reduced proliferation of keratinocytes
from the eccrine ducts can result in downregulation of
the re-epithelialization process in wound healing of partial-thickness ulcerations. Although the condition known
as Charcot foot is poorly understood, one of the main
steps in its pathogenesis is autonomic neuropathy withincreased blood flow to the bone. 1 2 Motor neuropathy
can lead to foot deformities from intrinsic muscle atrophy and imbalance of the muscles.1 0, 1 3 A common suchdeformity is the claw or hammer toe deformity. As thisoccurs, the fat pad is pulled off the metatarsal heads.
This may lead to high pressure points under the metatarsal heads on walking. Furthermore, sensory neuropathy
can disturb wound healing. Consequently, the mainstayof treatment for Type I wounds is pressure relief.
In a representative case, a 45-year-old woman who had
had diabetes mellitus for five years was worried about
ulceration beneath callus on her right sole due to Charcot
foot (Fig. 1). The wound gradually healed over 2 months
as a result of footwear prepared to achieve pressure relief, and the patient now wears her own prophylactic
shoes with no recurrence (Fig. 2).
Type II
Type II wounds mainly result from PAD. Fontaine IIIand IV scores for chronic ischemia represent criticallimb ischemia (CLI). Type II lesions are equivalent toFontaine IV. The most important consideration for thistype of lesion is to gain adequate blood flow to thewound with revascularization therapy. There are manyassessment tools for circulation. Among them, we believe that the skin perfusion pressure (SPP) around theKeio J Med 2011; 60 (1): 17－2119Fig. 2 Same patient as in Fig. 1; Two months after the therapy.
(A) The wound had healed.
(B) Lateral view.
(C) The patient’s own prophylactic insole.

wound is the most important.1 4 Especially in hemodialysis patients, SPP is the most useful tool for detecting
PAD, and has superior sensitivity and specificity to others, including the ankle-brachial index (ABI), the toebrachial index (TBI), and the transcutaneous oxygen
measurement (TcPO2).1 5 We define the dynamic SPP-1
measure as the SPP when the anterior tibial artery (ATA)
is occluded manually, and the dynamic SPP-2 measure
as the SPP when the posterior tibial artery (PTA) is occluded manually.16
For good wound healing, we have to recognize theoriginal angiosomes of the foot and find an alternative tothe ischemic angiosome through arterial-arterial connection using the angiogram view and dynamic SPP data.
Up to 15% of ischemic wounds cannot successfully heal
despite revascularization. 1 7 This failure is considered
due to inadequate revascularization of the wound and/or
inadequate wound care. Revascularization of the directly
supplying ischemic angiosome is more successful thanrevascularization of indirectly supplying angiosomes.1 8
In the vascularly compromised foot, collateral flow may
be keeping the ischemic angiosome vascularized to someextent, with the original vasculature changed. Therefore,
the plastic surgeon must plan to debride the necrotic tissue and gangrene and to cover the defects with the main
arterial flow kept intact and the collateral flow undisturbed. Understanding the vascular network facilitates
the design of incisions that sustain blood flow for thesurgical wound to heal well.19
A representative case is that of a 70-year-old man who
had dry necrosis on his right dorsum foot for 2 months.
He had diabetes mellitus and had undergone hemodialysis for 5 years. His anterior tibialis artery (ATA) and pos-Fig. 3 The patient is a 70-year-old man who had had diabetes
mellitus and had undergone hemodialysis for 5 years.
(A) Dry necrosis was present on the right dorsum foot for 2months.
(B) Debridement after revascularization.
(C) Wound bed preparation after negative pressure wound therapy.
(D) Six months after split-thickness skin grafting.

terior tibialis artery (PTA) were not palpable and the SPP
value on the dorsum of the foot was 30mmHg. We diagnosed his right leg as having CLI. After revascularization with distal femoral-PTA bypass surgery, debridement and negative pressure wound therapy were carriedout. Then, we grafted a split-thickness skin graft on thewound after wound bed preparation (Fig. 3).
Type III
Type III lesions are mainly caused by infection. Infections of various types are common and are often severein patients with diabetes mellitus. They indicate a serious acute problem requiring immediate surgical attention. Such wounds may be associated with long-term
morbidity, including soft tissue infection, osteomyelitis,
and the need for surgical resection. Consequently, it isimportant to assess the infectious wound accurately andto debride the necrotic devitalized soft tissues properly
in good time for acute phase infectious wounds. These

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Terashi H, et al: Total Management of Diabetic Foot Wounds in Asia

Fig. 5 A 65-year-old woman had gangrene of her right third toe
after an infection on the dorsum foot.
(A) Critical colonization into her central plantar space wasevident.
(B) Wound bed preparation after endovascular therapy andimmediate debridement.

Fig. 4 The patient is a 60-year-old woman who had sudden-onsetulceration.
(A) The wound generated much foul-smelling exudate.
(B) Five years after an immediate debridement without anyrecurrence.

infections can easily spread to the proximal side along
the tendons and fascia tissues. Early debridement anddrainage is the most important consideration for thewounds of Type III.
A representative case involved a 60-year-old woman
who had sudden onset ulceration with much foul-smelling exudate. The ATA and PTA were palpable. Laboratory data showed that CRP was 19.0mg/dl. Immediate debridement including resection of the fifth toe was carriedout and conservative therapy was then followed. The
wound had healed 1 month after the operation (Fig. 4).
Type IV
Type IV lesions are those caused by a combination of
all three factors (PN+PAD+infection). There were originally three basic anatomic types of major foot infection
in diabetes mellitus.2 0, 2 1 The first is infection from anulcerated bunion/bunionette that may enter the medial/
lateral plantar space. The second is from mal perforans
ulcers after callus formation. The third is abscess occur-ring chiefly in the central plantar spaces of the foot.
Most of the third type are secondary infections of theearly web space of the foot with patchy segmental arteriosclerotic occlusion of digital and metatarsal vessels on
tinea pedis, followed by thrombosis of arteries adjacently.2 1 Gangrene of the second, third, and/or fourth toes results. The mechanism is CLI from web space infection
as a result of an occult PAD. It is very difficult to manage Type IV wounds properly. If SPP is low, early debridement could result in worsened necrosis. If the infection is out of sight or critical colonization exists, the revascularization procedure could make the wounds more
infectious. When both procedures are needed, it is themost important which takes precedence and good timing
is important. The decision must be made on a case-bycase basis.
A representative case is that of a 65-year-old woman
who had gangrene of her third right toe after an infection
on the dorsum foot. The infection subsided and criticalcolonization occurred in the central plantar space (Fig.
5). SPP data were 20mmHg on the dorsum and 25mmHg
on the sole. First, revascularization therapy with an endovascular technique was done, followed by an immediate debridement before the expected infection could become established. After wound bed preparation with daily conservative therapy, SPP values of 60mmHg on thedorsum and 35mmHg on the sole were measured. A
modified transmetatarsal amputation was done. 1 9 The
patient has had no recurrence of ulceration and can walkeasily with her custom-made footwear (Fig. 6).
Discussion
Treatment must be conducted after proper assessment

Keio J Med 2011; 60 (1): 17－21

Fig. 6 Same patient as in Fig. 5; a modified transmetatarsal
amputation was done.
(A) During the operation.
(B) Just after the operation.
(C) One year after the operation.
(D) No recurrence of ulceration with custom-made footwear.

of diabetic foot wounds. This implies appropriate footcare and the use of proper footwear from the perspectives of prophylaxis and walking. Diabetic foot wounds
have some wound impairment factors, including PN,
PAD, and infection. These factors often occur in combination in such lesions. An additional goal besides woundhealing is gait salvage.
The newly proposed Kobe classification system issimple and easy to understand. First, we will try to apply
it in clinical practice and will modify it in the future if
necessary. The Kobe classification system will hopefully
provide a useful frame of reference when tackling difficult problems with respect to the assessment and thetreatment of a wide variety of troublesome wounds on
Asian diabetic feet.
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