Ischaemic Charcot Midfoot Reconstruction Combined with Lateral Tibial Cortex Transverse Transport: Case Report

Abstract

Charcot neuroarthropathy involving foot is a frequent and potentially a devastating complication of diabetes. In addition to good control of diabetes, surgical shoes and regular podiatric treatment, correction of foot deformity to prevent ulceration, deep infection and limb loss are now well established. Vascular insufficiency is common in this group of patients and traditional revascularisation procedures do not always succeed in healing ulcers and treating critical ischaemia. It compromises wound and bone healing. We report successful use of a modified technique of tibial cortex transverse transport (TTT) in a case where traditional revascularisation methods failed to correct critical ischaemia. We have achieved successful soft tissue and bone healing using this technique.

How to cite this article

Al Omar H, Lahoti O, Edmonds M, et al. Ischaemic Charcot Midfoot Reconstruction Combined with Lateral Tibial Cortex Transverse Transport: Case Report. Strategies Trauma Limb Reconstr 2025;20(1):50–55.

Introduction

Charcot neuroarthropathy of the foot is a devastating complication of diabetic peripheral neuropathy. Charcot deformity reconstruction is now frequently offered for functional limb salvage, delivered by a multi-disciplinary diabetic foot team (MDFT). The prevalence of peripheral arterial disease (PAD) in Charcot feet is high, and prior revascularisation (angioplasty or bypass procedure) in the presence of severe PAD should be performed before the deformity correction to minimise post-operative wound complications and the risk of bone non-union.^1,2 However, when the revascularisation procedures are not possible or fail, Charcot deformity reconstruction cannot be considered, and a below-knee amputation becomes inevitable.

Recently, the distraction histogenesis principle has been used to enhance the micro-vascularity of the limb for foot ulcers. This technique, tibial cortex transverse transport (TTT), involves a window of tibial cortical bone gradually pulled (transported) over three to four weeks to generate neovascularity in the entire limb segment. Tibial cortex transverse transport has been used successfully to promote ulcer healing and treat deep infections in ischaemic feet.^3–6 We report a case where we used a modified TTT technique and performed simultaneous midfoot Charcot reconstruction successfully in a critically ischaemic deformed Charcot foot that resulted in bone fusion of the osteotomies in 6 months and no further complications at the time of the last follow-up 27 months post-surgery.

Case Description

A 54-year-old gentleman with type 1 diabetes and an inactive right Charcot midfoot with a rocker-bottom deformity presented to our MDFT with recurrent plantar midfoot ulceration for over three years despite prolonged offloading measures. The background medical history included chronic kidney disease, diabetic retinopathy, peripheral neuropathy, and severe bilateral peripheral vascular disease (PVD), for which he had undergone multiple revascularisation procedures with no improvement in critical ischaemia. The patient had left trans-metatarsal amputation in the past for a diabetic foot infection compromised by vascular insufficiency.

Clinical examination revealed a plantar midfoot ulcer with an underlying palpable bone prominence along with rocker-bottom deformity and a tight Achilles tendon (Fig. 1). The midfoot medial and lateral columns joints showed excessive laxity. Anterior tibial and posterior tibial pulses were not palpable. Weight-bearing foot radiographs revealed extrusion of the cuneiforms and the cuboid, causing significant plantar bony prominence and a rocker-bottom deformity (Fig. 2). An arterial duplex scan revealed heavily calcified crural vessels, a patent peroneal artery with biphasic flow suggestive of no significant stenosis, occlusion of the posterior tibial artery from mid-calf reconstituting at the ankle with monophasic flow and a peak systolic velocity (PSV) of 0.3 m/s, lateral plantar artery occlusion, monophasic flow of the medial plantar artery with PSV of 0.2 m/s and a patent dorsalis pedis artery with monophasic flow and PSV of 0.5 m/s.

Fig. 1.

Clinical photograph of the right foot showing two plantar ulcers at the level of midfoot

Figs 2A and B.

Plain weight-bearing radiographs of the right foot (A) Lateral view showing a rocker-bottom Charcot foot deformity and disruption of tarsometatarsal and naviculo-cuneiform joints. Plantar prominence of the cuneiforms and cuboid, an increase of Meary's angle, negative cuboid height, and a decrease of the calcaneal pitch are also noted; (B) Dorsoplantar view: showing a forefoot abduction deformity

The ulcer failed to heal completely despite foot offloading in a bivalved total contact cast and custom footwear along with periods of non-weight-bearing for over three years. The vascular team of the MDFT concluded that the PVD of the right foot was non-treatable as multiple previous angioplasty procedures had failed, and they were concerned that any surgical wounds on the foot might not heal due to the degree of ischaemia (Fig. 3). After a series of MDFT discussions, the conclusion was to correct the foot deformity to provide functional limb salvage. The team agreed to combine the midfoot reconstruction procedure with TTT to improve microcirculation, thereby preventing wound and bone healing complications. An episode of superficial infection of the ulcer before the reconstruction was corrected by performing bedside ulcer debridement and administration of a course of targeted antibiotics. Once the ulcer infection cleared, we proceeded with combined TTT and open midfoot corrective surgery.

Fig. 3.

Post-infrapopliteal angioplasty of the right lower limb showing no improvement of the flow at the level of the foot

Traditionally, a cortical window is created on the medial side of the proximal tibia and pulled medially to create transverse transport. The senior author (OL) was concerned about possible wound healing problems medially over the shin due to poor peripheral circulation and lack of subcutaneous tissue. If soft tissues fail to heal, they expose the bone window and the risk of osteomyelitis is high. So, a modified technique was used that involved creating a lateral cortical window and pushing it “outwards” (laterally), thereby preventing wound complications (Fig. 4). The window remains well covered by the anterolateral group of muscles, and wound breakdown is less likely in this area.

Fig. 4.

Lateral TTT technical steps: Step 1: Expose the lateral side of the tibia through a skin incision a finger breadth lateral to the crest of the tibia. Strip the periosteum along with anterolateral muscles to expose the lateral surface of the tibia. Step 2: Mark the unicortical segment of the lateral cortex for transverse transport: 3 cm wide × 6 cm long. Mark it with multiple drill holes and make sure it is unicortical. Complete the cut on the posterior margin of the window because getting to this area will be difficult once the olives are inserted. Step 3: Introduce 1.6 or 2 mm k wires from lateral to medial × 3 tips emerging on the medial side. Step 4: Over-drill the k wire (3.5 mm cannulated drill) up to the inner side of the lateral cortex window, but not through it. This track will allow the olive to pass up the medial side of the transport segment. Repeat this procedure for all three wires and introduce olive wires from medial to lateral, exiting the tips through the lateral muscular compartment and skin. Step 5: Set up a two-ring Ilizarov frame using two long plates. On the medial side, the wires are held in place with a wire capture bolt, but do not tighten them hard: The wires should be allowed to be pulled from the lateral side. On the lateral side, use slotted rods to capture the wire ends and set up a transverse transport mechanism to pull the wires transversely in a lateral direction. Step 6: Start transverse distraction five through seven days post-surgery. Pull the wires 1 mm a day (preferably divided into 0.5 mm twice a day) for four weeks. Then X-ray the tibia. The frame can be removed at 6 weeks post-surgery

On the day of surgery, a diabetic foot surgeon (VK) first performed a Charcot midfoot reconstruction procedure. The superficial plantar ulcer was debrided and cleaned. After re-draping the limb, medial and lateral midfoot incisions were used to access the medial, middle, and lateral columns. All midfoot joints intended for fusion were thoroughly prepared. The deformity was corrected by performing osteotomies and stabilised using the principle of durable long-segment rigid fixation with optimal bone opposition. The medial column was stabilised using a beam inserted from the head of 1st metatarsal (MT) into talus and a locking plate, the middle column with one beam inserted from the head of 3rd MT into calcaneum and the lateral column with a locking plate from the base of 5th MT to calcaneum (Fig. 5). The Achilles tendon was lengthened percutaneously by performing a triple hemi-section using Hoke's technique to achieve a plantigrade foot. The limb reconstruction surgeon (OL) then performed the TTT. A lateral cortical window measuring approximately 4 × 1.5 cm was created by approaching the lateral cortex of the tibia by subperiosteally carefully elevating the anterolateral muscles. The fascial incision extended proximally and distally under the skin to create a fasciotomy to prevent a rare risk of compartment syndrome from a corticotomy. The Ilizarov circular frame apparatus was modified to facilitate the transportation of this segment outwards (Fig. 4). The Ilizarov frame was then extended distally to protect the midfoot reconstruction without transfixing the foot with wires (Fig. 6).

Fig. 5.

Intraoperative fluoroscopy images of the right foot showing the foot realignment and fixation with beams and plates and screws

Fig. 6.

Intraoperative clinical photo showing the modified frame extended to protect the right foot reconstruction

Post-operatively, the leg was elevated, and the patient was mobilised non-weight-bearing. Bedside physiotherapy was commenced focusing on an active right hip and knee range of mobilisation exercises. Chemical thromboprophylaxis was provided for 6 weeks as per the hospital protocol. Pin site care started on the 2nd day and was continued by the patient at home.

Distraction Protocol

Gradual lateral transport was commenced on the 7th post-operative day at the rate of one millimetre per day (0.5 mm every 12 hr). Lateral transverse transport was continued for four weeks, achieving 25–30 mm transport. The Ilizarov frame was removed 12 weeks post-application. Transverse transport generated good regeneration and healed well (Fig. 7).

Figs 7A to C.

Plain radiograph of the right tibia: (A) Anteroposterior (AP) at application; (B) AP end of distraction and (C) AP and lateral post-removal

Follow-up

The TTT procedure and foot surgery wounds healed completely within 3 weeks. The foot was protected in a non-weight-bearing total contact cast for three months after the removal of the frame. The post-operative foot radiographs taken at 6 months revealed good bone healing across both medial and lateral column osteotomies (Fig. 8). The patient progressed to full weight-bearing in custom shoes and insoles. At the time of the last follow-up, at 27 months post-surgery, the patient remained ambulatory in shoes, the foot remained stable, and the ulcer had not recurred (Fig. 9). Weight-bearing foot radiographs taken at 24 months revealed complete consolidation of the midfoot osteotomy, with a small plantar bone overgrowth and no metal work failure (Fig. 10).

Fig. 8.

Seated weight-bearing plain radiographs taken at 6 months post-operative showing solid union of the right foot osteotomies

Fig. 9.

Clinical photographs of the right leg and foot showing all wounds healed

Fig. 10.

Standing weight-bearing plain radiographs at 24 months post-operative showing complete consolidation at osteotomy sites with plantar bone overgrowth

Discussion

A deformed Charcot midfoot often results in ulceration despite offloading measures. Midfoot Charcot deformities follow predictable patterns and require specific techniques for surgical reconstruction.⁷ Reconstruction of a deformed Charcot foot results in predictable ulcer healing and prevention of ulcer recurrence.⁸ In the presence of ischaemia, prior revascularisation is needed before proceeding with the reconstruction procedure. However, if ischaemia cannot be rectified by angioplasty or arterial bypass procedure, reconstruction of the deformity is not possible, and a major amputation becomes inevitable.

Many studies, predominantly from China, have been published over the past few years on the effectiveness of the TTT technique in treating recalcitrant diabetic foot ulcers. Meta-analysis and multi-centre prospective studies have proven their efficacy in promoting ulcer healing and reducing ulcer recurrence and amputation rates.^3–6

The TTT principle is based on Ilizarov's law of tension stress, where gradual, slow traction of tissues in a stable environment causes them to become metabolically activated, increasing the proliferative and biosynthetic functions.^9–11 This restores the blood flow to the limb by building a rich microcirculation network in the distal part of the limb. Recent studies have suggested that TTT promotes wound healing by controlling the local wound inflammation and systemically via stem cell mobilisation and regulation.^12–15 Tibial cortex transverse transport has other corollary benefits. Studies have shown a significant improvement in neuritic pain and an increase in skin temperature post-TTT.⁴ Other studies compared pre- and post-operative CT angiogram examinations, which had shown a significant improvement in limb perfusion.¹⁶

The TTT technique has evolved from using an Ilizarov circular fixator to a dedicated unilateral external fixator system to simplify whole procedure. It has also enabled the use of serial distraction and compression manoeuvres, the so-called “accordion” technique to further enhance the effect of tension stress.

Tibia cortex transverse transport has been used in combination with other modalities of treatment such as negative pressure wound therapy and autologous platelet-rich plasma to shorten the healing period and minimise complications.¹⁷ It has also been used in combination with antibiotic-embedded bone cement to control the infection and increase the local blood supply.¹⁸ However, no published report combines TTT with the Charcot foot reconstruction procedure for the correction of ischaemic Charcot midfoot deformity. In this case, we have harnessed the benefits of TTT to achieve both soft tissue and bone healing.

We performed TTT during ischaemic Charcot midfoot reconstruction to improve the foot microcirculation post-operatively so that wound and bone healing complications could be avoided. We identified good wound healing response at 3 weeks post-operatively and excellent healing of bone osteotomies at 6 months. Transporting the lateral tibial cortex laterally resulted in no wound healing complications while providing optimal improvement in the microcirculation of the limb distally. In addition, a distal extension of the Ilizarov frame gave us the benefit of providing offloading of the operated foot, as applying a total contact cast while the leg frame was on would not be possible. The extended circular frame also protected against tibial fracture.

Conclusion

Simultaneous lateral cortex TTT and Charcot midfoot reconstruction resulted in good soft tissue and bone healing and an excellent functional outcome in a patient with concomitant non-correctable critical ischaemia due to PAD. This method can be further evaluated for the surgical management of ischaemic Charcot foot deformities to achieve functional limb salvage.

Orcid

Hussain Al Omar https://orcid.org/0000-0002-9680-4470

Michael Edmonds https://orcid.org/0000-0002-8931-0069

Venu Kavarthapu https://orcid.org/0000-0002-7184-4433