Tibial cortex transverse transport facilitating healing in patients with recalcitrant non-diabetic leg ulcers

Efficacy of tibial cortex transverse transport in treating diabetic foot ulcer and its effect on serum omentin-1 and irisin levels

OBJECTIVE

Diabetic foot ulcer (DFU) is a common and debilitating complication of diabetes that is associated with an increased risk of lower-limb amputation and a reduced life expectancy. Tibial cortex transverse transport (TTT) has become a newly alternative surgical method to facilitate ulcer healing and prevent lower limb amputation. Herein, we investigated the efficacy of TTT in treating DFU and changes of serum omentin-1 and irisin levels.

METHODS

This study prospectively recruited 52 consecutive patients with DFU who were treated with TTT. The follow-up was performed weekly during the first 12 weeks postoperatively and every 3 months until 1 year after TTT. The serum levels of vascular endothelial growth factor (VEGF), omentin-1, and irisin in DFU patients undergoing TTT were determined by ELISA methods on the preoperative 1st day, postoperative 2nd week and 4th week.

RESULTS

The wound healing rate was 92.3% (48/52) at the 1-year follow-up. The visual analog scale (VAS) pain scores of patients showed a significant reduction at the 4th week after TTT (p < 0.001). The dorsal foot skin temperature, ankle brachial index, and dorsal foot blood flow of patients were significantly increased at the 4th week after TTT (p < 0.001). Results of ELISA methods showed the serum levels of VEGF, omentin-1, and irisin on the 2nd week and 4th week after TTT were notably elevated compared to the levels determined on the preoperative 1st day (p < 0.001). The serum levels of VEGF, omentin-1, and irisin on the 4th week after TTT were also significantly higher than the levels determined on the 2nd week after TTT (p < 0.001).

CONCLUSION

TTT could promote the wound healing and reduce the risk of lower limb amputation, demonstrating promising clinical benefits in the treatment of DFU. Increased expressions of serum proangiogenic factors including VEGF, omentin-1, and irisin were noted in the early stage after TTT, which may provide a new mechanism of TTT promoting wound heal.

Tibial transverse transport induces mobilization of endothelial progenitor cells to accelerate angiogenesis and ulcer wound healing through the VEGFA/CXCL12 pathway

BACKGROUND

Tibial transverse transport (TTT) can promote the healing of chronic foot ulcers, but the specific cellular and molecular mechanisms by which TTT promotes wound healing remain unclear.

METHODS

New Zealand White rabbits were selected to induce foot ulcer models. The treatment included unilateral TTT surgery and bilateral TTT surgery. Observation of tissue neovascularization structure by HE staining and CD31 immunofluorescence detection. Collagen fiber formation was detected through the Masson staining. The mobilization of endothelial progenitor cell (EPCs) were analyzed by VEGFR2 immunofluorescence detection and flow cytometry detection of the number of VEGFR2/Tie-2-positive cells in peripheral blood. ELISA and qPCR assay were performed to detect VEGFA and CXCL12 levels.

RESULTS

The complete healing time of ulcer surfaces in sham, unilateral and bilateral TTT groups was about 22 days, 17 days and 13 days, respectively. TTT treatment significantly increased the deposition of granulation tissue and epithelialization of wounds. It also led to an increase in collagen fiber content and the level of the microvascular marker CD31. Furthermore, TTT treatment upregulated the levels of VEGFA and CXCL12 in peripheral blood and wound tissues, as well as increased the expression of VEGFR2 in wound tissues and the proportion of VEGFR2/Tie-2 in peripheral blood. Moreover, these effects of TTT treatment in the bilateral group was more significant than that in the unilateral group.

CONCLUSIONS

TTT may facilitate wound fibroblasts to release VEGFA and CXCL12, causing EPC mobilization, thus promoting angiogenesis and ulcer wound healing.

Impact of tibial transverse transport in tissue regeneration and wound healing with perspective on diabetic foot ulcers

In this editorial, we comment on an article by Liao et al published in the current issue of the World Journal of Diabetes. We focus on the clinical significance of tibial transverse transport (TTT) as an effective treatment for patients with diabetic foot ulcers (DFU). TTT has been associated with tissue regeneration, improved blood circulation, reduced amputation rates, and increased expression of early angiogenic factors. Mechanistically, TTT can influence macrophage polarization and growth factor upregulation. Despite this potential, the limitations and conflicting results of existing studies justify the need for further research into its optimal application and development. These clinical implications highlight the efficacy of TTT in recalcitrant DFU and provide lasting stimuli for tissue re-generation, and blood vessel and bone marrow improvement. Immunomodulation via systemic responses contributes to its therapeutic potential. Future studies should investigate the underlying molecular mechanisms to enhance our understanding and the efficacy of TTT. This manuscript emphasizes the potential of TTT in limb preservation and diabetic wound healing and suggests avenues for preventive measures against limb amputation in diabetes and peripheral artery disease. Here, we highlight the clinical significance of the TTT and its importance in healing DFU to promote the use of this technique in tissue regeneration.

Tibial cortex transverse transport promotes ischemic diabetic foot ulcer healing via enhanced angiogenesis and inflammation modulation in a novel rat model

BACKGROUND

Tibial Cortex Transverse Transport (TTT) represents an innovative surgical method for treating lower extremity diabetic foot ulcers (DFUs), yet its underlying mechanisms remain elusive. Establishing an animal model that closely mirrors clinical scenarios is both critical and novel for elucidating the mechanisms of TTT.

METHODS

We established a diabetic rat model with induced hindlimb ischemia to mimic the clinical manifestation of DFUs. TTT was applied using an external fixator for regulated bone movement. Treatment efficacy was evaluated through wound healing assessments, histological analyses, and immunohistochemical techniques to elucidate biological processes.

RESULTS

The TTT group demonstrated expedited wound healing, improved skin tissue regeneration, and diminished inflammation relative to controls. Marked neovascularization and upregulation of angiogenic factors were observed, with the HIF-1α/SDF-1/CXCR4 pathway and an increase in EPCs being pivotal in these processes. A transition toward anti-inflammatory M2 macrophages indicated TTT's immunomodulatory capacity.

CONCLUSION

Our innovative rat model effectively demonstrates the therapeutic potential of TTT in treating DFUs. We identified TTT's roles in promoting angiogenesis and modulating the immune system. This paves the way for further in-depth research and potential clinical applications to improve DFU management strategies.

Tibial cortex transverse transport regulates Orai1/STIM1-mediated NO release and improve the migration and proliferation of vessels via increasing osteopontin expression

Background

Diabetic foot is a major complication of diabetes. The bone transverse transport method could be applied in clinics for treatment, which could improve the metabolism of the tissues via lasting distraction forces. However, the process' specific regulating mechanism is still unknown.

Methods

Based on the notion that the healing of bones involves the recruitment of calcium ions, in this study, we established the model of tibial cortex transverse transport (TTT) on rats and then used tissue immunologic detection, such as the double fluorescent staining to explore the expression of the calcium channels' calcium release-activated calcium modulator 1 (Orai1)/stromal interaction molecule 1 (STIM1), which belong to the store-operated calcium entry (SOCE) signaling pathways on the tissues around the bone transport area. By using the laser capture microdissection (LCM) tool, we acquired samples of tissues around the bone and endeavored to identify pivotal protein molecules. Subsequently, we validated the functions of key protein molecules through in vitro and in vivo experiments.

Results

After protein profile analysis, we found the differentially expressed key protein osteopontin (OPN). The in vitro experiments verified that, being stimulated by OPN, the migration, proliferation, and angiogenesis of human umbilical vein endothelial cells (HUVEC) were observed to be enhanced. The activation of Orai1/STIM1 might increase the activity of endothelial nitric oxide synthase (eNOS) and its effect on releasing nitric oxide (NO). Subsequently, the migration and proliferation of the HUVECs are improved, which ultimately accelerates wound healing. These signaling pathway was also observed in the OPN-stimulated healing process of the skin wound surface of diabetic mice.

Conclusion

This study identifies the molecular biological mechanism of OPN-benefited the migration and proliferation of the HUVECs and provides ideas for searching for new therapeutic targets for drugs that repair diabetes-induced wounds to replace invasive treatment methods.

The translational potential of this article

The OPN is highly expressed in the tissues surrounding the TTT bone transfer area, which may possibly stimulate the activation of eNOS to increase NO release through the SOCE pathway mediated by Orai1/STIM1. This mechanism may play a significant role in the angiogenesis of diabetic foot's wounds promoted by TTT, providing new therapeutic strategies for the non-surgical treatment for this disease.

Efficacy and safety of unilateral tibial cortex transverse transport on bilateral diabetic foot ulcers: A propensity score matching study

Background

Tibial Cortex Transverse Transport (TTT) has been demonstrated to be an effective treatment for unilateral diabetic foot ulcers (UDFUs). However, this retrospective study was designed to compare the efficacy and safety of unilateral TTT on bilateral diabetic foot ulcers (BDFUs).

Methods

This retrospective study included a review of patients with TTT treated from January 2017 to August 2019, Propensity Score Matching (PSM) was performed to compare patients with BDFUs to those with UDFUs. Ulcer healing, recurrence, and major amputation rates were evaluated at 1-year follow-up. Changes in foot vessels were assessed in the BDFUs group using computed tomography angiography (CTA).

Results

A total of 140 patients with DFUs (106 UDFUs and 34 BDFUs) were included in the study. UDFUs and BDFUs were matched in a 1:1 ratio (34 in each group) using PSM. No significant difference was observed at 1-year-follow-up [91.2% (31/34) vs. 76.5% (26/34), OR 0.315 (95% CI 0.08 to 1.31), P ​= ​0.10] and 6-month-follow-up [70.6% (24/34) vs. 50.0% (17/34), OR 0.85 (95% CI 0.15 to 1.13), P ​= ​0.08] in two groups. Significant differences in rates of major amputation and recurrence between the groups (P ​> ​0.05) were not observed. The BDFUs group appeared more angiogenesis of the foot by CTA after 8 weeks of operation.

Conclusion

Results of this study suggest that severe BDFUs can be effectively treated by unilateral TTT. TTT is easy to operate and effective, which may be a good alternative for treating severe BDFUs.

The translational potential of this article

In previous retrospective clinical studies, TTT has demonstrated promising clinical outcomes in the management of diabetic foot ulcers. In this current study, we aim to investigate the potential use of TTT in treating distant tissue defects by evaluating the limited availability and safety of TTT for the management of bilateral diabetic foot. While additional basic and clinical research is necessary to fully elucidate the underlying mechanisms, our study offers insight into the potential therapeutic use of TTT for this condition.

Anterior superior iliac spine distraction for severe and recalcitrant diabetic foot ulcers

PURPOSE

The study aimed to introduce anterior superior iliac spine distraction to treat severe and recalcitrant diabetic foot ulcers. For comparison, we also included another group of diabetic foot ulcers treated with proximal tibial cortex transverse distraction.

METHODS

From February 1998 to February 2020, 87 patients (87 feet) with severe and recalcitrant diabetic foot ulcers were treated. The mean age of patients at surgery was 64 years (range, 47 to 87 years). The severity of the narrowed artery was assessed using the ankle-brachial index test. For comparison, another group of 91 patients (91 diabetic foot ulcers) treated with proximal tibial cortex transverse distraction was included.

RESULTS

The mean preoperative ankle-brachial indexes of the two groups were 0.41±0.07 and 0.39±0.05 (OR 0.65 [95% CI -0.77 to 1.58]; P=0.62), respectively. The mean preoperative limb pain was 3.42±2.84 cm and 3.52±3.11 cm (OR 1.54 [95% CI -077 to 1.35]; P=0.083), respectively. At the 2-year follow-up visit, ulcers healed in 72 (83%) and 74 (81%) patients, respectively (P=0.188). The mean postoperative limb pain was 0.52±0.23 cm and 0.49±0.41 cm (OR 2.32 [95% CI -0.27 to 1.66]; P=0.078), respectively. Pin-site infection occurred in 2 patients and 8 patients (P=0.09), respectively. Ulcer recurrence occurred in 13 (15%) patients and 15 (16%) patients (P=0.205), respectively.

CONCLUSIONS

Anterior superior iliac spine transverse distraction may be an effective alternative treatment for severe and recalcitrant diabetic foot ulcers. It may be associated with fewer distraction-site complications than proximal tibial cortex transverse distraction.

LEVEL OF EVIDENCE

Therapeutic study, Level IIa.

Outcomes of integrated surgical wound treatment mode based on tibial transverse transport for diabetic foot wound

Background

Diabetic foot ulcer (DFU) is frequently difficult to heal and finally leads to amputation, resulting in high mortality rate in diabetic patients. To date, effective and optimal therapies are still lacking. This study aims to investigate the efficacy of integrated surgical wound treatment (ISWT) mode on diabetic foot wound.

Methods

From January 2021 to December 2021, 13 diabetic foot patients with Wagner grade 3 to 4 were treated with ISWT mode, which combined TTT technique with debridement, induced membrane technique, vacuum sealing drainage (VSD) technique and skin grafting technique. The time of wound healing, the skin temperature at midpoint of dorsum of affected foot (T), visual analogue scale (VAS) score and ankle-brachial index (ABI) was measured before and after surgery. CTA examination of the lower extremity arteries was performed at the end of the cortex transport to evaluate the small arteriolar formation of the lower extremity. The complications occurred in each patient were recorded.

Results

13 patients with age ranging from 45 to 66 years were followed up for 3 to 13 months. All patients healed completely without amputation being performed, no serious complications were found except for one case of nail channel infection. The mean healing time was 25.8 ± 7.8 days, with a range of 17 to 39 days. The mean time of carrying external fixation scaffolds and resuming walking was 71.8 ± 10.0 and 30.8 ± 9.1 days, with a range of 56 to 91 days and 18 to 45 days, respectively. The skin temperature at midpoint of dorsum of affected foot (T), VAS and ABI was all improved significantly at 3 months after surgery. Furthermore, CTA examination showed an increase in the number of lower extremity arteries and a thickening in the size of small arteriolar compared with those of pre-operative, and the collateral circulation of lower extremity was established and interweaved into a network.

Conclusion

Integrated surgical treatment of diabetic foot wound can achieve satisfactory clinical results.

Effectiveness of transverse tibial bone transport in treatment of diabetic foot ulcer: A systematic review and meta-analysis

Background

Diabetic foot ulcerations (DFUs) are a common but highly morbid complication of long-standing diabetes, carrying high rates of associated major amputation and mortality. Transverse tibial bone transport (TTT) has recently been applied for treatment of DFUs with the aim of accelerating wound healing. This study was performed to evaluate the effectiveness and safety of TTT in patients with DFUs.

Methods

Two authors independently retrieved the platforms of PubMed, Embase and CENTRAL, to identify studies associated with treatment of DFUs with TTT. Quantitative meta-analyses were performed to pool all available outcomes about the effectiveness and complications of TTT operation, with fixed- (I2<50%) or random-effect (I2>50%) model according to I2.

Results

A total of 7 studies, involving 818 participants, were included, with 661 participants treated with TTT operation. The pooled healing rate and limb salvage rate were 0.96 (95%CI: 0.93~0.98) and 0.98 (95%CI: 0.95~1.00) respectively after treatment with TTT. The pooled mean healing time was 15.03 (95%CI: 9.05~21.00) months. When compared with the pre-operative baseline values, the ankle-brachial index (ABI, MD: 0.23; 95%CI: 0.03~0.44; p<0.001), skin temperature (MD: 1.56; 95%CI: 0.30~2.81; p<0.001), and visual analogue scale (VAS, MD: 3.70; 95%CI: 1.97~5.44; p<0.001) were significantly improved at the final follow-up. When compared with non-TTT group, the TTT group was associated with higher healing rate (OR: 10.43; 95%CI: 3.96~27.43; p<0.001) and limb salvage rate (OR: 9.65; 95%CI: 3.30~28.20; p<0.001). Concerning the complications of the TTT process, the pooled risks of fracture at transportation site and pin-site infection were 0.02 (95%CI: 0.00~0.04) and 0.08 (95%CI: 0.00~0.22), respectively; and the DFU recurrence rate in TTT group was significantly lowered comparing to that of the non-TTT group (RR: 0.18; 95%CI: 0.06~0.49; p=0.001).

Conclusions

TTT operation was associated with high healing rate and limb salvage rate, and could significantly improve the ABI, skin temperature, and VAS after operation. When compared with the control group, TTT group provided significantly higher healing rate and limb salvage rate. However, TTT operation should be conducted with caution concerning the incidences of fracture at tibia, infection at pin channels and necrosis of skin overlying the anterior tibia.

Triplanar osteotomy combined with proximal tibial transverse transport to accelerate healing of recalcitrant diabetic foot ulcers

BACKGROUND

Management of recalcitrant diabetic foot ulcers remains challenging. Tibial transverse transport (TTT) is an effective method for enhancing the healing of foot ulcers. This retrospective study reports a novel triplanar osteotomy in the tibia and assesses the clinical outcomes of TTT for diabetic foot ulcers.

METHODS

Fifty-nine patients with recalcitrant diabetic foot ulcers were divided into the TTT (32 patients) and control (27 patients) groups. In the TTT group, the patients underwent triplanar osteotomy of the proximal tibia, followed by 2 weeks of medial distraction and 2 weeks of lateral distraction. In the control group, the patients received conventional management, including debridement, revascularization, and reconstruction. Ulcer healing and healing time, amputation, recurrence, and complications were assessed at an 18-month follow-up visit. Computed tomography angiography (CTA) was used to evaluate vessel changes in the lower limbs of patients in the TTT group.

RESULTS

The TTT group was superior to the control group in the healing rate (90.6% [29/32] vs. 66.7% [18/27]) and the healing time (4.6 ± 1.7 months vs. 7.4 ± 2.5 months), respectively. The proportions of amputation and recurrence in the TTT group were lower than that in the control group, without statistical difference. After triplanar osteotomy and transverse distraction, CTA demonstrated an increase in small vessels in the wound and ipsilateral limb. All patients achieved satisfactory union of the osteotomized bone fragment after removal of the external fixator.

CONCLUSIONS

Triplanar osteotomy combined with proximal tibial transverse distraction accelerates wound healing and limb salvage caused by severe and recalcitrant diabetic foot ulcers. Triplanar osteotomy not only increases the bone contact area, which is beneficial for rapid bone reconstruction, but also preserves the vascularization of the bone fragment and substantially facilitates capillary angiogenesis during distraction. These results suggest that triplanar osteotomy followed by tibial transverse distraction is an effective method for treating diabetic foot ulcers.

Twenty Years Development of Tibial Cortex Transverse Transport Surgery in PR China

Tibial cortex transverse transport (TTT) surgery is an extension of the Ilizarov technique. Based on the law of tension‐stress, its primary function is to rebuild microcirculation which can relieve ischemic symptoms and promote wound healing. It has received more and more scholars' attention and has experienced a series of changes for 20 years since it entered PR China. The mechanisms involved have gradually become clear, such as the reconstruction of the polarization balance of macrophages, the promotion of vascular tissue regeneration, and the mobilization and regulation of bone marrow‐derived stem cells. TTT technique is mainly used in the treatment of chronic ischemic diseases of the lower extremities. It has recently been successfully used in the treatment of primary lymphedema of the lower extremities. A series of improvements have been made in the external fixator's style, the size of skin incision and osteotomy, and distraction method. For example, the annular external fixator has been redesigned as a unilateral external fixator, and accordion technology has been introduced. For distraction methods after surgery, there was no uniform standard in the past. The technique can also be used in combination with other treatments to achieve better effects, such as interventional therapy, negative pressure sealed drainage, 3D printing technology, traditional Chinese medicine. Nevertheless, the surgery may bring some complications, such as secondary fracture, nail infection, skin necrosis at the surgical site, etc. Reports of complications and doubts about the technique have made the TTT technique controversial. In 2020, the relevant expert consensus was published with treatment and management principles, which might guide the better application and development of this technique.

[Transverse distraction osteogenesis : New chances for limb salvage?]

Distraction osteogenesis (DO) is a technique that can be successfully used to treat leg length discrepancies and to reconstruct long defects of bone. By gradual distraction of the bone fragments by approximately 1 mm per day, hypervascularization and an increased bone healing potential (growth stimulus) occur. So far, DO has almost exclusively been used longitudinally to generate new biologically active bone. Chronic wounds, ulcers and osteitis, especially in the region of the foot, are always a challenge for the treating surgeon, since treatment is tedious, the outcome uncertain and associated with possible loss of the extremity. Transverse distraction osteogenesis (tDO) now uses the growth stimulus of the DO translationally to treat distally located, chronic wounds and thus leads to accelerated wound healing. At the end of the 5‑week treatment, the transversely distracted fragment, located far proximal to the chronic wound, is back in its original location. The biological stimulus has a long-lasting effect, longer than the tDO itself. Further investigations into the mechanisms of action and treatment outcomes of tDO are required. If the previous results are confirmed, tDO may become a game changer and enable the limb salvage for a large proportion of findings that previously required amputation.

Tibial Cortex Transverse Distraction Followed by Open Correction with Internal Fixation for Management of Foot and Ankle Deformity with Ulcers

OBJECTIVE

To assess the feasibility and results of tibial cortex transverse distraction (TCTD) followed by open correction with internal fixation (OCIF) for foot and ankle deformity with concurrent ulcers.

METHODS

A retrospective analysis was conducted. Between 2010 and 2019, a two-stage management of TCTD followed by OCIF was performed in 13 patients (13 feet). There were five males and eight females with a mean age of 33.8 ± 14.6 years. Ten patients had a right-side lesion, and three patients had a left-side lesion. The etiology of deformity included seven cases of congenital neurological disease, one case of Charcot-Marie-Tooth disease, one case of trauma sequelae, and three cases of myelomeningocele. Duration of disease, size of ulcers, surgical procedures, healing time, external fixation time, and complications of these patients were recorded. The Texas wound classification and National Pressure Ulcer Advisory Panel (NPUAP) classification were used for assessing the ulcers. The modified Dimeglio score of deformity and American Orthopeadic Foot and Ankle Society (AOFAS) ankle-hindfoot score were applied to evaluate the status before treatment and the results at final follow-up.

RESULTS

The TCTD and wound debridement were performed in all patients, and an additional Ilizarov correction technique was added in two patients. All ulcers were healed in 3 months after first-stage treatment. The median patient self-report time of ulcer healing was 2.0 weeks (IQR, 1.8-3.3). The median external fixation time was 138.0 days (IQR, 134.5-141.5) days. After second-stage operative correction, the patients were followed-up for an average of 28.0 ± 2.9 months. At the final follow-up, the modified Dimeglio score of deformity was decreased from 6.7 ± 2.1 to 1 (IQR, 0.0-1.0), and the mean AOFAS score was improved from 42.9 ± 19.1 to 82.6 ± 7.7. Before the treatment, there were eight patients with severe deformity, four patients with moderate deformity, and one patient with mild deformity. Postoperatively, seven patients were classified as mild deformity and six patients had a postural foot. The results of AOFAS ankle-hindfoot score were defined as excellent in three patients, as good in five, and as fair in five. Complications include one case of mild displacement of the osteotomized cortex and one case of pin-tract infection. No delayed union, nonunion, relapse of ulcers, or deformity were observed.

CONCLUSIONS

The two-stage management of TCTD followed by OCIF could be considered as an alternative treatment for foot and ankle deformities combined with chronic ulcers.

[Treatment of severe diabetic foot ulcer using tibia transverse transport combined with nose ring drain]

Objective

To investigate the effectiveness of tibial transverse transport (TTT) combined with nose ring drain (NRD) in the treatment of severe diabetic foot ulcer.

Methods

The clinical data of 60 patients with severe diabetic foot (Wagner grade 3 or 4) ulcer who were admitted between April 2017 and August 2020 and met the selection criteria were retrospectively analyzed. Among them, 30 cases were treated with TTT combined with NRD (TTT+NRD group), and 30 cases were treated with TTT (TTT group). There was no significant difference in gender, age, diabetes duration, preoperative glycated hemoglobin, comorbidities, wound area, and duration, side, and grade of diabetic foot ( P>0.05). The wound healing time, wound healing rate, amputation rate, recurrence rate, duration of antibiotic therapy, hospital stay, number of hospitalizations, and number of operations were recoreded and compared between the two groups.

Results

No obvious surgical complications occurred in the two groups. Patients in both groups were followed up 3-13 months, with an average of 5.7 months. The duration of antibiotic therapy and hospital stay in the TTT+NRD group were significantly shorter than those in the TTT group ( P<0.05). There was no significant difference in wound healing time, wound healing rate, number of hospitalizations, and number of operations between the two groups ( P>0.05). During follow-up, there was no recurrence of ulcer in the TTT+NRD group while 2 recurrent cases (6.7%) in the TTT group. The difference in recurrence rate was not significant ( P=0.492). One case (3.3%) in the TTT+NRD group underwent amputation due to acute lower extremity vascular embolism, and 1 case (3.3%) in the TTT group underwent amputation due to secondary necrosis. The difference in amputation rate was not significant between the two groups ( P=1.000).

Conclusion

TTT combined with NRD is an effective method for the treatment of severe diabetic foot ulcers with deep infections or relatively closed cavities or sinuses. It can shorten the time of antibiotic use and the length of hospitalization; and the NRD has a good drainage effect without obvious comorbidities, procedure and the postoperative care are simple and easy to obtain materials.