- Email: [email protected]
Impact of local surgery on the healing of refractory diabetic foot ulcerations
Foot and Ankle Surgery 2001
7: 103±108
Impact of local surgery on the healing of refractory diabetic foot ulcerations1 È F FE R , M . W I T T E , G . D E U T S C H LE , S. COERPER, M. SCHA È C. WICKE, G. KOVEKER AND H.D. BECKER University of TuÈbingen, Department of General Surgery, TuÈbingen, Germany
Summary
We evaluated the role of local surgery on the treatment of patients with refractory diabetic ulcers referred to a specialized wound care centre. Therapy was performed according to a comprehensive wound care protocol, characterized by an interdisciplinary approach, radical local surgery, off-loading and moist wound dressings. Conservative local wound treatment obviously led to a long wound duration and a high frequency of bone involvement and so-called refractory diabetic ulcers in a patient population (n 138) that was referred to our wound care centre. Here, local surgery was performed extensively (95%). Probably as a result of radical surgery, healing rates were calculated by life-table analysis to 90% within 52 weeks, independently of ulcer depth, wound duration or wound infection. According to a multivariate analysis, only heel ulcers (P 0.03) and old age (P 0.01) were negative predictors for healing. These results con®rm the great impact of local surgery, especially in the treatment of severe diabetic ulcers. Keywords: diabetic foot syndrome; diabetic ulcer; wound debridement
Introduction Foot ulceration is a common complication in patients with diabetes mellitus. Ten percent of the diabetic population will develop foot ulcers at some stage of their disease [1]. The reasons for ulceration, such as peripheral neuropathy (PNP) and atherosclerosis, are well recognized [2±4], however, the rates of major amputations remains high [5]. Initially, ulceration may involve the super®cial tissue, but prolonged ulceration can lead to severe bone infection. Therefore, soft tissue infection and osteomyelitis are Correspondence: Stephan Coerper, MD, University of TuÈbingen, Department of General Surgery, Hoppe-Seyler Str. 3, 72076 TuÈbingen, Germany (e-mail: [email protected]). 1
This paper was presented, in part, at the 115th Annual Conference of the German Society of Surgery in Berlin on 28 April 1998. Ó 2001 Blackwell Science Ltd
major complications of diabetic ulcers and may increase the risk of amputation [6, 7]. The degree of ulceration and infection can be graded by the Wagner or Knighton et al. classi®cation [8, 9]. Nevertheless, there is little information about their therapeutic implications and impact on healing rates. In previous studies, surgical debridement was demonstrated to be essential for healing of diabetic ulceration [10, 11]. Other studies focused on risk factors for amputation such as ischaemia, age or wound infection [12, 13]. In Germany, there is no general agreement to a standardized therapy for diabetic foot ulcers. Six years ago, we established a comprehensive and interdisciplinary wound care protocol for patients with chronic wounds. Patient data was collected prospectively using a specially designed wound documentation programme [14]. The aim of this study was to analyse the role of 103
1 04
S . C O E R P ER E T A L .
standardized local surgery on refractory diabetic foot ulcers.
Methods Patients were treated in cooperation with the departments of internal medicine and radiology, and a specialized orthopaedic technician. The coordination of all diagnostic and therapeutic procedures as well as wound care was performed in the surgical wound care unit. Physical examination including measurement of PNP using mono®laments, plain ®lm radiography (PFR) and transcutaneous measurement of the pO2 (tcpO2) at the dorsum of the foot represent the basic diagnostic procedures. Angiography in ischaemic lesions and microbiological testing of infected ulcers were addi1 tional diagnostic steps. Revascularization by PTA or vascular surgery were performed if indicated, before starting local therapy according to our protocol. Offloading of forefoot and heel ulcers was achieved with a special shoe (Cabrio or Comet by Thanner, HoÈchstaÈdt, Germany). Mid-foot ulcers or Charcot feet were treated with individually modi®ed orthotic devices. Wound therapy started with a sharp radical debridement down to healthy and bleeding tissue. Callus and necrotic tissue were removed and exposed bone was resected (Figure 1). Osteolysis in the PFR or open laying bone was de®ned as bone involvement and treated with limited and soft tissue-preserving bone resection. Osteomyelitis was proved by histological examination of the removed bone. Wound dressings (saline, 0.9%) were changed twice a day, at home by the general practitioner or home care organizations. Wound data was collected weekly until the end of treatment. The end of treatment was de®ned as healing of the lesion, discontinuation of therapy and after a treatment time of a maximal 12 months. We documented general patient data (age, patient history, wound duration, wound localization), all diagnostic and therapeutic procedures, wound grading, extension of granulation tissue or necrosis and wound infection. Wound size was measured using planimetry and ulcer depth and expressed in cm3 (area ´ depth). The aim of the study was to evaluate whether radical local surgery will create a wound environment to guarantee rapid wound closure, independ-
Figure 1 Plantar deep foot ulcer with bone involvement (a). Local surgery consisted of limited bone resection by dorsal incision (b) and plantar excisional wound debridement (c). Healed ulcer 4 month later (d).
ently of ulcer depth, wound duration, infection and ulcer localization, even in refractory diabetic foot ulcers. For this evaluation, wounds were graded according to ulcer depth at baseline: super®cial ulcers involving the dermis (grade I), subcutaneous ulcers (grade II), ulcers with open laying tendon or fascia (grade III), and deep ulcers with bone involvement (grade IV). Infection was de®ned clinically by local signs such as oedema, erythema or purulent wound secretion. Wounds were de®ned as healed 4 weeks after complete epithelization, when scar was considered to be resistant to weight bearing in specially designed shoes. Ischaemia was de®ned for patients with no palpable dorsal pedis or tibialis posterior pulses. The severity of ischaemia was evaluated by tcpO2. Patients were subdivided into young (< 60 years) and old (> 60 years) patient groups. Wound duration was classi®ed as short (< 6 weeks) or long (> 6 weeks) and compliance was de®ned as bad if patients did not comply with regular wound dressings or off-loading devices. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
LOCAL SURGERY AND DIABETIC FOOT ULCERATIONS
Before therapy the prognosis for healing was estimated subjectively as favourable or poor. Statistics were calculated using the statistical program SPSS 9.0, values expressed by mean SEM and range. Differences between groups were calculated using the two-tailed t-test. The absolute healing rates were expressed as the percentage of patients during treatment time. At the ®nal day of data collection some patients were still on treatment. These patients still have a chance to heal. To calculate the overall probability for ulcer healing, we used life-table (log rank test) analysis. This statistical method calculates the overall probability for healing based on the data of completely treated patients.
Results We report about 117 patients with diabetes mellitus type II and 21 patients with diabetes mellitus type I. Patients were referred to our wound care centre by the general practitioner who de®ned ulceration as severe and resistant to previous therapy after a treatment of an average 13.5 2.3 months (1±240). There were 95 male and 43 female patients, 61.2 0.9 years (26±90) of age. According to the baseline examination, out of 138 patients 32 (23%) had no palpable pulses and were de®ned as having ischaemic feet. Most of these patients (n 24) had additional signs of polyneuropathy according to sensory measurements. There were only six patients with severe ischaemia (tcpO2 < 20 mmHg); all these patients had PTA (n 4) or vascular surgery (n 2). The average tcpO2 of all ischaemic feet was 40 2 mmHg (5±48). Ulcers were at the plantar forefoot (`Malum perforans') in 51% of patients, in 26% at the toes, in 9% at the heel and in 14% at other regions. Wounds were graded as grade II in 38% of patients, as grade III in 6% and as grade IV in 56%. No ulcer was grade I. At baseline there were several characteristics of advanced ulcerous disease: the mean wound volume was 9.3 + 2.0 cm3 (0.2±18.4), 65% of all ulcers had undermining wound edges and 59% were found to have severe callus around the ulcer. Severe wound infection at baseline led to immediate hospitalization in 9% of the cases. The overall signi®cant infection rate during follow-up in the entire study was 18%. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
10 5
Prior wound therapy was heterogeneous: only 15 patients (12%) reported surgical wound debridement. Orthopaedic shoe wear was used in 19% of patients, but complete off-loading was seen in only two patients. The 138 patients were treated for a mean of 14 1.0 weeks (1±67), 41% were treated exclusively as out-patients and hospitalization was indicated for wound infection or major surgery for a mean of 12 1.5 days (1±62). Ninety-®ve percent had local surgery; of these, 38% of patients had a second operation, 18% a third and 12% more than three operations. In total there were 228 operations in 138 patients. Major debridements were carried out in 45% of patients (n 102). Soft tissue-preserving bone resection was carried out in 36% of patients (n 83). Minor (toe, forefoot) amputations were performed in 16% of patients (n 36). Major amputations (upper and lower leg) were carried out in 3% of patients (n 7) (Figure 2). Operations were performed on out-patients in 57% of cases. Additional minor wound debridements were performed on 56% of cases. According to life-table analysis, the overall probability for ulcer healing was 0.65 within 6 months and 0.9 within 1 year (Figure 3). Ulcer localization had an impact on the probability of ulcer healing: compared with all ulcers, the healing of heel ulcers was delayed (P 0.05), but the probability for the healing of toe ulcers was increased (P 0.04). There was a trend for delayed healing of initially infected ulcers (P 0.07) and patients with poor compliance (P 0.06). Despite all information from
Figure 2 Local surgery (n 228) on 138 patients with diabetic foot ulcer.
1 06
S . C O E R P ER E T A L .
Figure 3 Cumulative probability of ulcer healing based on the follow-up of 138 patients.
the diagnostic work-up, the initial clinical judgement alone had a high predictive value (P 0.005). Wound duration, ulcer grade or bone resection had no impact on the healing of diabetic foot ulcer according to univariate analysis. Calculating the covariates, old patients (P 0.01) and patients with heel ulcers (P 0.03) have a signi®cantly lower chance of healing and clinical judgement remains highly predictive (P 0.002) (Table 1). Other parameters such as ulcer depth, wound duration, bone surgery or wound infection did not seem to be predictive values for the healing of diabetic foot ulcers.
Discussion Foot ulceration is a burden for the diabetic population and affects the quality of life [15±17]. Despite effective health care programmes, the incidence and
Figure 4 Newly designed off-loading device for heel ulcer.
recurrent rates of diabetic foot ulceration is still high [18±22]. Patient morbidity and amputation rates, however, can be improved by interdisciplinary wound care programmes [23, 24]. Sharp excision and debridement of the callus as well as the bony prominence has been recognized and advocated in the literature [11, 25, 26]. We present the analysis of a patient population with chronic and non-healing diabetic foot ulcers that were de®ned by the general practitioner as resistant to therapy. We revealed several characteristics demonstrating the severity of diabetic foot disease on the investigated patient population: there is a long wound duration of 13.5 months and a high percentage (56%) of diabetic ulcers with bone
Covariates
Healing rates during treatment
Univariate (log rank)
Multivariate (Cox regression)
Clinical judgement of bad prognosis Heel ulcer Toe ulcer Infection Bad compliance Old age ( 60 years) Sex (male/female) Long wound duration (> 52 weeks) Ischaemia (no pulses) Forefoot ulcer Wound grade (III and IV) Bone resection
48% 33% 61% 58% 31% 59% 60%/63% 57% 51% 57% 58% 54%
0.005* 0.05* 0.04* 0.07 0.06 0.1 0.2 0.6 0.5 0.9 0.6 0.6
0.001* 0.04* 0.8 0.2 0.1 0.02* 0.2 0.3 0.2 0.4 0.5 0.4
Table 1 Univariate and multivariate (Cox regression) analysis of different parameters that might interfere with healing
Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
LOCAL SURGERY AND DIABETIC FOOT ULCERATIONS
involvement. Surprisingly, the probability of ulcer healing was high in these patients according to our protocol and was calculated by life-table analysis to 90% within 1 year of treatment. We believe that aggressive local surgery has a major part in the treatment of these patients. In this study, it improved ulcer healing and showed high healing rates independently of wound duration, ulcer depth and wound infection. As seen in the high percentage of callus and undermining wound edges found on admission, local surgery had rarely been carried out before patients were referred to our wound care centre. Although diagnostic testing for osteomyelitis remains controversial [27], it has been proved that surgical treatment with limited bone resection improves the healing rate and time to healing compared with conservative therapeutic approaches [28]. In our study, appropriate local surgery led to an inevitably high percentage of bone resection. This was performed mostly by limited bone resections (36%), preserving the plantar surface, in consideration of the high recurrent rates after excessive reduction of the weight-bearing area [22]. These extensive wound debridements, however, were not characterized by a high infection rate (18%) compared with other studies [25]. Several studies show the importance of consequent and complete off-loading [4]. In this study, off-loading was achieved with individually designed devices. Interestingly, heel ulcers were characterized by a signi®cantly lower healing rate than other localizations. This may be explained by incomplete off-loading of the ulcerated heel by the prescribed off-loading device (Thanner, HoÈchstaÈdt, Germany). These results forced us to modify this shoe with a special back bow, preventing pressure from the bottom and the back to improve further healing in patients with heel ulcers (Figure 4). According to the literature, one might expect a higher number of patients with severely ischaemic feet. In this study, only six patients had severe ischaemia with tcpO2 values lower than 20 mmHg and all six received revascularization. We cannot therefore verify the outcome of local surgery on patients with ischaemia owing to the small number of patients or evaluate the role of tcpO2 as a predictive indicator. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
10 7
Conclusions Patients with severe diabetic ulcers were treated without operation before being referred to our wound care centre. A radical surgical approach improved healing. Local surgery should be performed during the early stages of ulcerous disease to limit further destruction of the foot integrity. We conclude that, in Germany, a standardized wound care protocol for diabetic ulcers is still not well accepted and treatment regiments depend on the individual decisions of the various departments. We need to create a standardized and interdisciplinary wound care programme that will improve healing rates and decrease amputation rates, according to the declaration of Saint Vincent [29].
References 1 Zlatkin MB, Pathria M, Sartoris DJ et al. The diabetic foot. Radiol Clin North Am 1987; 25: 1095±1105. 2 Apelqvist J, Larsson J, Agardh CD. Medical risk factors in diabetic patients with foot ulcers and severe peripheral vascular disease and their in¯uence on outcome. J Diabet Comp 1992; 6: 167±174. 3 Boulton AJM. End-stage complications of diabetic neuropathy: foot ulceration. Can J Neurol Sci 1994; 21: 18±22. 4 Katoulis EC, Boulton AJM, Raptis SA. The role of diabetic neuropathy and high plantar pressures in the pathogenesis of foot ulceration. Horm Metab Res 1996; 28: 159±164. 5 Standl E, Mendler G, Zimmermann R et al. On the prevalence of lower limb amputations in diabetic patients in Germany: results of a survey in two counties. Diab Stoffw 1996; 5: 29±32. 6 Bridges RM, Deitch EA. Diabetic foot infections. Pathophysiol Treatment Surg Clin North Am 1994; 74: 537±555. 7 Bamberger DM, Daus GP, Gerding DN. Osteomyelitis in the feet of diabetic patients. Long-term results, prognostic factors and the role of antimicrobial and surgical therapy. Am J Med 1987; 83: 653±660. 8 Wagner FW. Treatment of the diabetic foot. Compr Ther 1984; 10: 29±38. 9 Knighton DR, Ciresi KF, Vance D et al. Classi®cation and treatment of chronic non healing wounds. Successful treatment with autologous platelet derived wound healing factors (PDWHF). Ann Surg 1986; 204: 322±330. 10 Steed DL, Donohoe D, Webster MW et al. Effect of extensive debridement and treatment on the healing of diabetic foot ulcers. J Am Coll Surg 1996; 183: 61±64. 11 Piaggesi A, Schipani E, Campi F et al. Conservative surgical approach versus non-surgical management for diabetic neuropathic ulcers: a randomized trial. Diabet Med 1998; 15: 412±417. 12 Apelqvist J, Castenfors J, Larsson J et al. Wound classi®cation is more important than site of ulceration in the outcome of diabetic foot ulcers. Diabetic Med 1989; 6: 526±530. 13 Bennett PJ, Stocks AE, Whittam DJ. Analysis of risk factors for neuropathic foot ulceration in diabetes mellitus. J Am Podiatr Med. Assoc 1996; 86: 112±116.
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14 Deutschle G, Coerper S, Merkh M et al. Quality assessment by standardised wound documentation ± A report of 6 years experience. Wound Rep Reg 1998; 6: A465. 15 Carrington AL, Mawdsley SK, Morley M et al. Psychological status of diabetic people with or without lower limb disability. Diabetes Res Clin Pract 1996; 32: 19±25. 16 Reiber GE. The epidemiology of diabetic foot problems. Diabet Med 1996; 13: S6±S11. 17 Reiber GE, Lipsky BA, Gibbons GW. The burden of diabetic foot ulcers. Am J Surg 1998; 176: 5S±10S. 18 Abbott CA, Vileikyte L, Williamson S et al. Multicenter study of the incidence and predictive risk factors for diabetic neuropathic foot ulceration. Diabetes Care 1998; 21: 1071±1075. 19 Boulton AJM. Guidelines for diagnosis and outpatient management for diabetic peripheral neuropathy. European association for the study of diabetes, neurodiabetes. Diabetes Metab 1998; 24: 55±65. 20 Boulton AJM. Lowering the risk of neuropathy, foot ulcers and amputations. Diabet Med 1998; 15: 57±59. 21 Boulton AJM, Meneses P, Ennis WJ. Diabetic foot ulcers: a framework for prevention and care. Wound Rep Reg 1999; 7: 7±16. 22 Mantey I, Foster AV, Spencer S et al. Why do ulcers recur in diabetic patients? Diabet Med 1999; 16: 245±249.
23 Armstrong DG, Harkless LB. Outcomes of preventive care in a Diabetic foot speciality clinic. J Foot Ankle Surg 1998; 37: 460±466. 24 Holstein PE, Sorensen S. Limb salvage experience in a multidisciplinary diabetic foot unit. Diabetes Care 1999; 22: B97±B103. 25 Wheat LJ, Allen SD, Henry M et al. Diabetic foot infections. Arch Intern Med 1986; 146: 1935±1940. 26 HaVan G, Siney H, Danan JP et al. Treatment of osteomyelitis in the diabetic foot. Contribution of conservative surgery. Diabetes Care 1996; 19: 1257±1260. 27 Enderle M, Coerper S, Schweizer HP et al. Correlation of imaging techniques to histopathology in patients with diabetic foot syndrome and clinical suspicion of chronic osteomyelitis. The role of high-resolution ultrasound. Diabetes Care 1999; 22: 294±299. 28 Coerper S, Flesch I, Gottwald T et al. The resection of the metatarsal head: a surgical approach to the `Mal perforant du pied' of diabetic patients. Diab Stoffw 1996; 380: 102±107. 29 World Health Organisation and International Diabetes Federation. Diabetes care and research in Europe: The St. Vincent declaration. Diabet Med 1990; 7: 360±362.
Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
7: 103±108
Impact of local surgery on the healing of refractory diabetic foot ulcerations1 È F FE R , M . W I T T E , G . D E U T S C H LE , S. COERPER, M. SCHA È C. WICKE, G. KOVEKER AND H.D. BECKER University of TuÈbingen, Department of General Surgery, TuÈbingen, Germany
Summary
We evaluated the role of local surgery on the treatment of patients with refractory diabetic ulcers referred to a specialized wound care centre. Therapy was performed according to a comprehensive wound care protocol, characterized by an interdisciplinary approach, radical local surgery, off-loading and moist wound dressings. Conservative local wound treatment obviously led to a long wound duration and a high frequency of bone involvement and so-called refractory diabetic ulcers in a patient population (n 138) that was referred to our wound care centre. Here, local surgery was performed extensively (95%). Probably as a result of radical surgery, healing rates were calculated by life-table analysis to 90% within 52 weeks, independently of ulcer depth, wound duration or wound infection. According to a multivariate analysis, only heel ulcers (P 0.03) and old age (P 0.01) were negative predictors for healing. These results con®rm the great impact of local surgery, especially in the treatment of severe diabetic ulcers. Keywords: diabetic foot syndrome; diabetic ulcer; wound debridement
Introduction Foot ulceration is a common complication in patients with diabetes mellitus. Ten percent of the diabetic population will develop foot ulcers at some stage of their disease [1]. The reasons for ulceration, such as peripheral neuropathy (PNP) and atherosclerosis, are well recognized [2±4], however, the rates of major amputations remains high [5]. Initially, ulceration may involve the super®cial tissue, but prolonged ulceration can lead to severe bone infection. Therefore, soft tissue infection and osteomyelitis are Correspondence: Stephan Coerper, MD, University of TuÈbingen, Department of General Surgery, Hoppe-Seyler Str. 3, 72076 TuÈbingen, Germany (e-mail: [email protected]). 1
This paper was presented, in part, at the 115th Annual Conference of the German Society of Surgery in Berlin on 28 April 1998. Ó 2001 Blackwell Science Ltd
major complications of diabetic ulcers and may increase the risk of amputation [6, 7]. The degree of ulceration and infection can be graded by the Wagner or Knighton et al. classi®cation [8, 9]. Nevertheless, there is little information about their therapeutic implications and impact on healing rates. In previous studies, surgical debridement was demonstrated to be essential for healing of diabetic ulceration [10, 11]. Other studies focused on risk factors for amputation such as ischaemia, age or wound infection [12, 13]. In Germany, there is no general agreement to a standardized therapy for diabetic foot ulcers. Six years ago, we established a comprehensive and interdisciplinary wound care protocol for patients with chronic wounds. Patient data was collected prospectively using a specially designed wound documentation programme [14]. The aim of this study was to analyse the role of 103
1 04
S . C O E R P ER E T A L .
standardized local surgery on refractory diabetic foot ulcers.
Methods Patients were treated in cooperation with the departments of internal medicine and radiology, and a specialized orthopaedic technician. The coordination of all diagnostic and therapeutic procedures as well as wound care was performed in the surgical wound care unit. Physical examination including measurement of PNP using mono®laments, plain ®lm radiography (PFR) and transcutaneous measurement of the pO2 (tcpO2) at the dorsum of the foot represent the basic diagnostic procedures. Angiography in ischaemic lesions and microbiological testing of infected ulcers were addi1 tional diagnostic steps. Revascularization by PTA or vascular surgery were performed if indicated, before starting local therapy according to our protocol. Offloading of forefoot and heel ulcers was achieved with a special shoe (Cabrio or Comet by Thanner, HoÈchstaÈdt, Germany). Mid-foot ulcers or Charcot feet were treated with individually modi®ed orthotic devices. Wound therapy started with a sharp radical debridement down to healthy and bleeding tissue. Callus and necrotic tissue were removed and exposed bone was resected (Figure 1). Osteolysis in the PFR or open laying bone was de®ned as bone involvement and treated with limited and soft tissue-preserving bone resection. Osteomyelitis was proved by histological examination of the removed bone. Wound dressings (saline, 0.9%) were changed twice a day, at home by the general practitioner or home care organizations. Wound data was collected weekly until the end of treatment. The end of treatment was de®ned as healing of the lesion, discontinuation of therapy and after a treatment time of a maximal 12 months. We documented general patient data (age, patient history, wound duration, wound localization), all diagnostic and therapeutic procedures, wound grading, extension of granulation tissue or necrosis and wound infection. Wound size was measured using planimetry and ulcer depth and expressed in cm3 (area ´ depth). The aim of the study was to evaluate whether radical local surgery will create a wound environment to guarantee rapid wound closure, independ-
Figure 1 Plantar deep foot ulcer with bone involvement (a). Local surgery consisted of limited bone resection by dorsal incision (b) and plantar excisional wound debridement (c). Healed ulcer 4 month later (d).
ently of ulcer depth, wound duration, infection and ulcer localization, even in refractory diabetic foot ulcers. For this evaluation, wounds were graded according to ulcer depth at baseline: super®cial ulcers involving the dermis (grade I), subcutaneous ulcers (grade II), ulcers with open laying tendon or fascia (grade III), and deep ulcers with bone involvement (grade IV). Infection was de®ned clinically by local signs such as oedema, erythema or purulent wound secretion. Wounds were de®ned as healed 4 weeks after complete epithelization, when scar was considered to be resistant to weight bearing in specially designed shoes. Ischaemia was de®ned for patients with no palpable dorsal pedis or tibialis posterior pulses. The severity of ischaemia was evaluated by tcpO2. Patients were subdivided into young (< 60 years) and old (> 60 years) patient groups. Wound duration was classi®ed as short (< 6 weeks) or long (> 6 weeks) and compliance was de®ned as bad if patients did not comply with regular wound dressings or off-loading devices. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
LOCAL SURGERY AND DIABETIC FOOT ULCERATIONS
Before therapy the prognosis for healing was estimated subjectively as favourable or poor. Statistics were calculated using the statistical program SPSS 9.0, values expressed by mean SEM and range. Differences between groups were calculated using the two-tailed t-test. The absolute healing rates were expressed as the percentage of patients during treatment time. At the ®nal day of data collection some patients were still on treatment. These patients still have a chance to heal. To calculate the overall probability for ulcer healing, we used life-table (log rank test) analysis. This statistical method calculates the overall probability for healing based on the data of completely treated patients.
Results We report about 117 patients with diabetes mellitus type II and 21 patients with diabetes mellitus type I. Patients were referred to our wound care centre by the general practitioner who de®ned ulceration as severe and resistant to previous therapy after a treatment of an average 13.5 2.3 months (1±240). There were 95 male and 43 female patients, 61.2 0.9 years (26±90) of age. According to the baseline examination, out of 138 patients 32 (23%) had no palpable pulses and were de®ned as having ischaemic feet. Most of these patients (n 24) had additional signs of polyneuropathy according to sensory measurements. There were only six patients with severe ischaemia (tcpO2 < 20 mmHg); all these patients had PTA (n 4) or vascular surgery (n 2). The average tcpO2 of all ischaemic feet was 40 2 mmHg (5±48). Ulcers were at the plantar forefoot (`Malum perforans') in 51% of patients, in 26% at the toes, in 9% at the heel and in 14% at other regions. Wounds were graded as grade II in 38% of patients, as grade III in 6% and as grade IV in 56%. No ulcer was grade I. At baseline there were several characteristics of advanced ulcerous disease: the mean wound volume was 9.3 + 2.0 cm3 (0.2±18.4), 65% of all ulcers had undermining wound edges and 59% were found to have severe callus around the ulcer. Severe wound infection at baseline led to immediate hospitalization in 9% of the cases. The overall signi®cant infection rate during follow-up in the entire study was 18%. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
10 5
Prior wound therapy was heterogeneous: only 15 patients (12%) reported surgical wound debridement. Orthopaedic shoe wear was used in 19% of patients, but complete off-loading was seen in only two patients. The 138 patients were treated for a mean of 14 1.0 weeks (1±67), 41% were treated exclusively as out-patients and hospitalization was indicated for wound infection or major surgery for a mean of 12 1.5 days (1±62). Ninety-®ve percent had local surgery; of these, 38% of patients had a second operation, 18% a third and 12% more than three operations. In total there were 228 operations in 138 patients. Major debridements were carried out in 45% of patients (n 102). Soft tissue-preserving bone resection was carried out in 36% of patients (n 83). Minor (toe, forefoot) amputations were performed in 16% of patients (n 36). Major amputations (upper and lower leg) were carried out in 3% of patients (n 7) (Figure 2). Operations were performed on out-patients in 57% of cases. Additional minor wound debridements were performed on 56% of cases. According to life-table analysis, the overall probability for ulcer healing was 0.65 within 6 months and 0.9 within 1 year (Figure 3). Ulcer localization had an impact on the probability of ulcer healing: compared with all ulcers, the healing of heel ulcers was delayed (P 0.05), but the probability for the healing of toe ulcers was increased (P 0.04). There was a trend for delayed healing of initially infected ulcers (P 0.07) and patients with poor compliance (P 0.06). Despite all information from
Figure 2 Local surgery (n 228) on 138 patients with diabetic foot ulcer.
1 06
S . C O E R P ER E T A L .
Figure 3 Cumulative probability of ulcer healing based on the follow-up of 138 patients.
the diagnostic work-up, the initial clinical judgement alone had a high predictive value (P 0.005). Wound duration, ulcer grade or bone resection had no impact on the healing of diabetic foot ulcer according to univariate analysis. Calculating the covariates, old patients (P 0.01) and patients with heel ulcers (P 0.03) have a signi®cantly lower chance of healing and clinical judgement remains highly predictive (P 0.002) (Table 1). Other parameters such as ulcer depth, wound duration, bone surgery or wound infection did not seem to be predictive values for the healing of diabetic foot ulcers.
Discussion Foot ulceration is a burden for the diabetic population and affects the quality of life [15±17]. Despite effective health care programmes, the incidence and
Figure 4 Newly designed off-loading device for heel ulcer.
recurrent rates of diabetic foot ulceration is still high [18±22]. Patient morbidity and amputation rates, however, can be improved by interdisciplinary wound care programmes [23, 24]. Sharp excision and debridement of the callus as well as the bony prominence has been recognized and advocated in the literature [11, 25, 26]. We present the analysis of a patient population with chronic and non-healing diabetic foot ulcers that were de®ned by the general practitioner as resistant to therapy. We revealed several characteristics demonstrating the severity of diabetic foot disease on the investigated patient population: there is a long wound duration of 13.5 months and a high percentage (56%) of diabetic ulcers with bone
Covariates
Healing rates during treatment
Univariate (log rank)
Multivariate (Cox regression)
Clinical judgement of bad prognosis Heel ulcer Toe ulcer Infection Bad compliance Old age ( 60 years) Sex (male/female) Long wound duration (> 52 weeks) Ischaemia (no pulses) Forefoot ulcer Wound grade (III and IV) Bone resection
48% 33% 61% 58% 31% 59% 60%/63% 57% 51% 57% 58% 54%
0.005* 0.05* 0.04* 0.07 0.06 0.1 0.2 0.6 0.5 0.9 0.6 0.6
0.001* 0.04* 0.8 0.2 0.1 0.02* 0.2 0.3 0.2 0.4 0.5 0.4
Table 1 Univariate and multivariate (Cox regression) analysis of different parameters that might interfere with healing
Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
LOCAL SURGERY AND DIABETIC FOOT ULCERATIONS
involvement. Surprisingly, the probability of ulcer healing was high in these patients according to our protocol and was calculated by life-table analysis to 90% within 1 year of treatment. We believe that aggressive local surgery has a major part in the treatment of these patients. In this study, it improved ulcer healing and showed high healing rates independently of wound duration, ulcer depth and wound infection. As seen in the high percentage of callus and undermining wound edges found on admission, local surgery had rarely been carried out before patients were referred to our wound care centre. Although diagnostic testing for osteomyelitis remains controversial [27], it has been proved that surgical treatment with limited bone resection improves the healing rate and time to healing compared with conservative therapeutic approaches [28]. In our study, appropriate local surgery led to an inevitably high percentage of bone resection. This was performed mostly by limited bone resections (36%), preserving the plantar surface, in consideration of the high recurrent rates after excessive reduction of the weight-bearing area [22]. These extensive wound debridements, however, were not characterized by a high infection rate (18%) compared with other studies [25]. Several studies show the importance of consequent and complete off-loading [4]. In this study, off-loading was achieved with individually designed devices. Interestingly, heel ulcers were characterized by a signi®cantly lower healing rate than other localizations. This may be explained by incomplete off-loading of the ulcerated heel by the prescribed off-loading device (Thanner, HoÈchstaÈdt, Germany). These results forced us to modify this shoe with a special back bow, preventing pressure from the bottom and the back to improve further healing in patients with heel ulcers (Figure 4). According to the literature, one might expect a higher number of patients with severely ischaemic feet. In this study, only six patients had severe ischaemia with tcpO2 values lower than 20 mmHg and all six received revascularization. We cannot therefore verify the outcome of local surgery on patients with ischaemia owing to the small number of patients or evaluate the role of tcpO2 as a predictive indicator. Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108
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Conclusions Patients with severe diabetic ulcers were treated without operation before being referred to our wound care centre. A radical surgical approach improved healing. Local surgery should be performed during the early stages of ulcerous disease to limit further destruction of the foot integrity. We conclude that, in Germany, a standardized wound care protocol for diabetic ulcers is still not well accepted and treatment regiments depend on the individual decisions of the various departments. We need to create a standardized and interdisciplinary wound care programme that will improve healing rates and decrease amputation rates, according to the declaration of Saint Vincent [29].
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Ó 2001 Blackwell Science Ltd, Foot and Ankle Surgery 2001, 7, 103±108