ORIGINAL RESEARCH |
https://doi.org/10.5005/jp-journals-10040-1324 |
Midfoot Charcot and Need for Arch Reconstruction and Superconstruct—“Lessons Learnt”: Multicentric Indian Experience
1Department of Arthroscopy and Foot and Ankle, Ganga Hospital, Coimbatore, Tamil Nadu, India
2Department of Orthopedics, VPS Lakeshore Hospital, Kochi, Kerala, India
3,7Department of Orthopedics, Ganga Hospital, Coimbatore, Tamil Nadu, India
4Department of Foot and Ankle Reconstruction & Sportsmedicine, Foot Ark Clinic, Mumbai, Maharashtra, India
5,6Department of Arthroscopy and Foot and Ankle, Ganga Hospital, Coimbatore, India
8Department of Plastic Surgery and Diabetic Foot Surgery, Ganga Hospital, Coimbatore, Tamil Nadu, India
Corresponding Author: Silvampatti Ramasamy Sundararajan, Department of Orthopedics, Ganga Hospital, Coimbatore, Tamil Nadu, India, e-mail: sundarbone70@hotmail.com
Received on: 06 June 2023; Accepted on: 20 September 2023; Published on: 20 October 2023
ABSTRACT
Aims and background: Charcot’s neuroarthropathy (CN) affecting the midfoot leads to fractures and dislocation of the tarsal bones and displaced predominantly to the plantar aspect of the foot. Further, loading on these bony prominences leads to midfoot ulcers. Hence, corrective fusion of the involved medial and/or lateral columns is necessary to protect the foot from ulcers and recurrent infections. Our primary objective was to assess the radiological and functional outcomes of midfoot fusion in CN. A secondary aim was to estimate the incidence of complications such as loss of fixation, implant fracture, and wound dehiscence following the procedure.
Materials and methods: This is a retrospective study of all patients operated in three different centers by four different surgeons, between 2018 and 2022. All patients who were diagnosed with Charcot’s arthropathy of the midfoot were included in the study. Patients with hindfoot Charcot’s arthropathy, arthritis due to posttraumatic, inflammatory, and infective sequelae were excluded. Data (radiological and functional) of all patients in the three orthopedic centers were collected. Functional outcomes were assessed using the midfoot—American Orthopaedic Foot and Ankle Society (AOFAS) and Foot and Ankle Outcome Score (FAOS) scoring system preoperatively and at the final follow-up. Radiological assessment was done for union and the lateral talometatarsal (TMT) (Meary’s) angle, talo-first metatarsal angle in antero-posterior (AP) view, calcaneal pitch, and cuboid height were utilized for assessing the foot reconstruction in sagittal and axial planes.
Results: We had a total of 98 patients (center-1—55), (center-2—15), and (center-3—28) with a mean follow-up ranging from 10 ± 2 to 79 ± 12 months. There was significant improvement in midfoot AOFAS scores and FAOS postoperatively across the centers; however, it was statistically significant in center-1 (p-value = 0.0005) and center-2 (p-value = 0.042). Stable union (bony/fibrous) ranged between 78.5 and 95%. Meary’s angle improved in all centers, and it was statistically significant in center-1 (p-value = 0.0005), talar-1st MT angle in AP view, and cuboid height improved significantly in center-1 and 2 (p-value = 0.0005) while calcaneal pitch showed statistically significant improvement center-1 (p-value = 0.042), and center-3 (p-value = 0.0005). The total complication rate ranged between 46% and 51% [minor (6–23%), major (25–40%)] with screw breakage at the TMT junction being the most common complication encountered. The reoperation rate ranged from 0 to 27% across the centers. Only one patient needed amputation due to recurrent infection.
Conclusion: Based on the observations in this study, we would recommend early surgical intervention in midfoot CN. Medial and lateral column fusion with intramedullary beam screws with or without superconstruct results in an acceptable bony union/fibrous union that provides a plantigrade stable foot despite complications like implant breakage, loss of fixation, and wound infections.
How to cite this article: Ramakanth R, Simon R, Sundararajan SR, et al. Midfoot Charcot and Need for Arch Reconstruction and Superconstruct—“Lessons Learnt”: Multicentric Indian Experience. J Foot Ankle Surg (Asia-Pacific) 2023;10(4):198–207.
Source of support: Nil
Conflict of interest: This Author is removed from the Editorial Board, no need to add endogeny statement. Please proceed as it is.
Keywords: Beam screws, Charcot’s arthropathy, Diabetic mellitus, Lateral column fusion, Medial column fusion, Midfoot, Superconstruct
INTRODUCTION
Charcot neuroarthropathy (CN) is a chronic, debilitating, limb-threatening disorder of the musculoskeletal system characterized by progressive joint dislocation, pathological fractures, deformities, ulcer formation, and disability or amputation. Midfoot CN results in the collapse of the arch and rocker-bottom deformity, which modifies weight distribution and causes point loading over the plantar bony prominence, resulting in ulcer formation.1 The treatment of neuroarthropathic fractures and dislocations in the foot continues to be a challenge for the treating physician. In these instances, nonoperative treatment has remained the standard of care, and it is usually adequate in the early stage.2 However, the risk of gross instability of the foot leading to recurrent ulcerations and progressing to amputation has been well documented.3,4 In order to improve one’s quality of life, surgical stabilization of the foot is warranted to salvage the foot from recurrent ulcers and amputation.
CN has shown a predilection toward the midfoot.1 Brodsky categorized the condition based on commonly affected joints in the foot; the most common site being the midfoot (around 60%). A combination of factors is considered responsible, the most important being the presence of Achilles tendon tightness that increases pressure on metatarsophalangeal joints, leading to midfoot collapse.1,5,6 For this reason, many authors recommend early surgical stabilization in Charcot’s arthropathy of the midfoot.7
For unstable midfoot CN, medial, and or lateral column fusion has been suggested as a surgical treatment. However, the procedure is especially susceptible to complications such as infection, loss of fixation, nonunion, midfoot secondary collapse, and recurrent ulcerations.8-10 Poor bone quality, neuropathy, poor vascularity, and impaired nutrition of glycosylated tissues in diabetic patients delay arthrodesis site healing, union and contribute to complications.10 Important determinants of the eventual outcome include the choice of surgical technique, the type of implant, and the disease stage at the time of surgery.
In Charcot’s disease, the objective is to achieve a plantigrade foot that is stable, suitable for footwear, and ulcer-free.11,12 For these reasons, midfoot arthrodesis (long segment fusions) is recommended for both the medial and lateral columns of the foot. Meticulous technique, arch reconstruction, and inherent strength of the final construct are crucial factors that determine the final functional and radiological outcome.
In this case series, we discuss the outcomes of midfoot CN surgery performed in three distinct centers using either 6.5 mm cannulated cancellous screws or midfoot plates with iliac crest bone grafting. Our primary objective was to assess the radiological and functional outcomes of midfoot fusion in CN. A secondary aim is to estimate the incidence of complications such as loss of fixation, implant fracture, and wound dehiscence following the procedure.
Our hypothesis was that providing both column fusions results in a stable, plantigrade foot with a reduced risk of fixation loss. Using autogenous bone grafts increased the likelihood of union, and compression across the arthrodesis site via cancellous screws or midfoot plates ensured early radiological healing and improved functional outcomes.
MATERIALS AND METHODS
This is a retrospective study of all patients operated in three different centers by four different surgeons, between 2018 and 2022. Informed, written consent was obtained from all patients.
All patients who were diagnosed with Charcot’s arthropathy of the midfoot and who needed surgical stabilization of the joints in the form of midfoot arthrodesis were included in the study. Patients with hindfoot Charcot’s arthritis due to posttraumatic, inflammatory, and infective sequelae were excluded from the study. Patients are advised for surgery based on their preoperative assessment and indication for the surgery (Fig. 1).
Fig. 1: This is a flowchart showing preoperative parameters and indications for surgical management for midfoot Charcot’s arthropathy
All patients in all three orthopedic centers underwent detailed clinical examination, relevant radiological investigations in the form of weight-bearing X-rays, and preoperative data was systematically tabulated. All patients were classified according to the site of involvement as per Brodsky13 classification and staged according to Eichenholtz14 staging for Charcot’s arthropathy of the foot.
Patients’ demographic data sex, age, side of involvement, duration of symptoms (time to surgery), random blood sugar (RBS) at admission, glycated hemoglobin (HbA1c) (glycosylated hemoglobin at admission, diabetic status, duration of diabetic mellitus, duration of preop antibiotics, preoperative erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and joints involved were documented.
CENTER-SPECIFIC PROTOCOL AND SURGICAL TECHNIQUE
Orthopedic Center-1
Surgical techniques for each patient are chosen based on their clinical presentation (Fig. 2). All patients were operated on under epidural anesthesia. The patient was placed supine on the operating Table 2 dorsal incisions were used to expose the medial column joints and lateral column joints talometatarsal (TMT). Incisions were extended to expose the naviculocuneiform (NC), talonavicular (TN), and calcaneocuboid (CC) joints, respectively. After joint surfaces were denuded till fresh bleed, in several cases, substantial bone loss was found which was filled with tricortical iliac crest bone grafts. Alignment was checked under fluoroscopy. A necessary osteotomy was performed to obtain near anatomical alignment and a plantigrade foot. For medial column fusion, all joints first, second, and third TMT, NC, and TN joints, were exposed in all the cases. For lateral column fusion, fourth, fifth TMT and CC joints were exposed and articular cartilage was denuded. The choice of implant in our institute is long beam screws 6.5 mm cannulated cancellous screws (beam screws) that were inserted in the first MT to the talus for medial column fixation and the fourth MT to the calcaneum or though lateral aspect of MT into calcaneum for lateral column fixation. Additionally, another 6.5 mm screw was inserted from the lateral aspect of the shaft of the fifth MT into the calcaneum through cuboid bone for additional stability of the lateral column. The medial column is augmented with low profile 3.5 mm plates, inserted dorsally, which provides adequate stability and called a “superconstruct.” The wound was closed meticulously (Fig. 3). In a consolidated foot with plantar bony prominences, exostectomy was performed to relieve the plantar surface pressure (Fig. 4). All patients were immobilized in below-knee POP cast for 8–10 weeks and nonweight-bearing walking (NWB) was continued till 3 months. Patients were mobilized partial weight-bearing walking (PWB) with controlled ankle motion (CAM) boot for another 1 month and advised to wear this appliance for almost 6–8 months until the sign of radiological union.
Fig. 2: This is an algorithm showing decision-making for different modes of Charcot’s presentation and treatment options
Figs 3A to D: (A) Example of the patient (center-1) showing a preoperative clinical picture of the right foot from medial, lateral, posterior, and anterior aspects with dorsal prominence in the midfoot region, healed ulcer on the medial aspect foot, flatfoot and forefoot broadened (splaying); (B) Preoperative X-rays showing TMT Charcot with collapse of the arch and widening of the forefoot; (C) This picture showing the principle of fixation in the Charcot where all medial column bones are aligned to talus and lateral column bone are aligned to calcaneum; (D) Showing comparison of preoperative and postoperative X-rays TMT angle corrected from 18.5 to 9° and Meary’s angle being corrected from 43 to 3° with no secondary varus collapse at 1.3 years of follow-up and good consolidation at the midfoot
Figs 4A to F: Example of the patient (center-1) showing (A) Preoperative X-ray of midfoot Charcot with arch collapse; (B) Immediate postoperative X-ray showing good arch reconstruction; (C) 1.6 years follow-up X-ray showing secondary arch collapse with implant breakage with consolidated medial and lateral column; (D) 2 years follow-up X-ray after implant removal presented with plantar ulcer due to plantar bony prominence; (E) Patient was taken up for lateral approach and exostectomy; (F) Shows C-arm picture after exostosis
Orthopedic Center-2
Before surgery, patients in center-2 endure a meticulous multidisciplinary evaluation. Assessing blood glucose with HbA1c, renal parameters, and vascularity with a color Doppler scan is required. Patients with monophasic flow are referred to the vascular team for angioplasty, and if underlying vascularity improves, they are scheduled for midfoot surgery.
Weight-bearing radiographs are taken whenever practicable and are extremely beneficial for evaluating the mechanical alignment of the foot. In our center, early instances are treated with a total contact cast (TCC). Only in cases involving associated foot ulcers or imminent ulcers, we do recommend early surgery. After exostectomy is performed, the wound is allowed to recuperate, and in the second stage, midfoot reconstruction is performed.
All of the aforementioned conditions must be fulfilled before midfoot surgery can be scheduled at our facility, where we select patients who comply with our recommendations. We have used plates (Fig. 5) beam screws, or a combination of both for midfoot fixation. In a few patients, subtalar joint screw fixation has also been performed, but its stability remains uncertain.
Figs 5A to F: Example of the patient showing (center-2) showing (A to C) Clinical picture of the patient with a plantar ulcer before and after debridement and preoperative X-ray of midfoot Charcot with arch collapse in lateral view; (D) Immediate postoperative X-ray showing good arch reconstruction where the medial and lateral column was stabilized with 3.5 mm locking plates; (E and F) Showing bony union with no secondary collapse at 1.4 and at 2 years follow-up with healed ulcer and good consolidation at the midfoot
All the medial column joints are prepared following a medial approach. Correct alignment is achieved using a curved osteotome. In most cases, beam screws are used for lateral fixation; however, in a few instances, plates have been employed.
Orthopedic Center-3
All patients were operated on under general anesthesia as we do not stop blood thinners during the perioperative period. The patient was positioned supine with a tourniquet applied at the proximal thigh level. Midfoot TMT and hindfoot intertarsal (subtalar) joints were exposed with one medial and one dorsal incision respecting the internervous planes and angiosome for posterior tibialis artery (PTA) and dorsalis pedis artery (DPA). Underlying joint deformities and exostosis were liberally resected to fresh bleeding bones and fixed with a superconstruct configuration. This included a medial long-spanning reconstruction plate spanning from the talus to the first metatarsal, a 6.5 screw to fix the subtalar joint, a dorsal reconstruction plate at the second or third TMT joint (depending on the apex of deformity in midfoot), an additional one or two screws transfixing the fourth and fifth metatarsals to the tarsals. Bone voids were filled with antibiotic-impregnated cortico-cancellous allografts. The wound was closed meticulously.
All patients were immobilized in below-knee plaster of paris (POP) cast for 8–10 weeks and NWB was continued for 3 months. Patients were mobilized PWB with CAM boot for another 1 month and advised to wear this appliance for almost 6–8 months until the sign of radiological union.
Follow-up
Patients were followed up at intervals of 6 weeks, 3, 6, 12, 18, and 24 months, and yearly after. Functional outcomes were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot rating system15 and Foot and Ankle Outcome Score (FAOS)16 preoperatively and at the final follow-up. X-rays were analyzed for union status, time to union, loss of correction (secondary collapse), and implant breakage. Radiological assessment was recorded for preoperative and postoperative measurement of Meary’s angle, (Fig. 3), antero-posterior (AP view) first TMT angle, calcaneal pitch, and cuboid height. Meary’s angle was measured as the angle formed from a axis-line bisecting the talar body and neck and a axis-line bisecting the first metatarsal and a similar angle in the AP view constituted the AP first TMT angle. The calcaneal pitch was measured as the angle between the reference line from the plantar aspect of the calcaneal tuberosity to the plantar aspect of the fifth metatarsal head and a line extending from the most plantar aspect of the calcaneal tuberosity to the most plantar aspect of the anterior process of the calcaneus. Cuboid height was measured as the perpendicular distance (mm) from the plantar aspect of the cuboid to a line drawn from the plantar aspect of the calcaneal tuberosity to the plantar aspect of the fifth metatarsal head.17
Stable union included complete bony union in both columns and fibrous union in one or both columns without clinical/symptomatic midfoot instability. Those with radiological evidence of union were considered bony union, those with radiolucency at the fusion site but clinically stable feet were considered fibrous union and those who had neither radiological evidence nor a clinically stable foot were considered nonunion. Complications in all centers were classified as minor and major complications. Those complications (Fig. 6) that required a major surgical intervention like deep infection, screw breakage that required removal under anesthesia/amputation, ulcer, or exostosis requiring exostectomy, were considered major. Those that required minor intervention such as daycare or conservative treatment were considered minor (superficial infection, minor implant failures like screw back out, stable midfoot with implant breakage that doesn’t warrant implant removal).
Figs 6A to D: Examples of complications in different patients. (A) Dorsal ulcer with cellulitis and diffuse infection; (B) Screw back out; (C) Exostosis on the plantar aspect with 6.5 mm screw breakage; (D) X-ray of patient with partial union and secondary collapse
Statistical Analysis
The collected data were analyzed with the International Business Machines (IBM) Corporation Statistical Package for the Social Sciences statistics for Windows, Version 29.0 (Armonk, New York: IBM Corp).To describe the data descriptive statistics mean and standard deviation (SD) were used. To find the significant difference between the bivariate samples in paired groups the paired sample t-test was used. In the above statistical tool, the probability value 0.5 was considered a significant level.
RESULTS
The preoperative demographic and biochemical data are summarized in Table 1. The results are summarized based on the data available. The final outcome was significantly better compared to their preoperatives values in all three centers, which are tabulated in Table 2. The union rate and final radiological outcomes were significantly better than the preoperative values in all three centers (Tables 2 and 3).
| Data | Orthopedic center-1 | Orthopedic center-2 | Orthopedic center-3 | ||
|---|---|---|---|---|---|
| Number of patients* (n) | 55 | 15 | 28 | ||
| Age (years)† | 64.5 ± 9.3 | 54.4 ± 8.8 | 59.2 ± 6.4 | ||
| Average follow-up (months)† | 22 ± 3.8 | 79.06 ± 12.19 | 10.2 ± 1.9 | ||
| Duration of symptoms (months) † | 11.4 ± 6.5 | 15.4 ± 17.8 | 34.2 ± 12.44 | ||
| Side | Left | 31 (56.4%) | 7 (46.6%) | 10 (35.7%) | |
| Right | 24 (43.6%) | 8 (53.4%) | 18 (64.3%) | ||
| Sex | Male | 40 (72.7%) | 9 (60%) | 25 (89.2%) | |
| Female | 15 (27.3%) | 6 (40%) | 3 (10.8%) | ||
| Duration of diabetes (years)† | 15.5 ± 6.5 | – | 14.5 ± 4.2 | ||
| Duration of preoperative antibiotics (weeks)† | 4 ± 0.7 | – | – | ||
| RBS (mg/dL)† | 227.4 ± 82.3 | 227.2 ± 64.7 | 189.2 ± 45.9 | ||
| HbA1c† | 7.95 ± 1.7 | 8.6 ± 2.3 | 7.87 ± 0.6 | ||
| Diabetic status (no. of patients) | Controlled | 19 (34.5%) | 4 (26.6%) | 11 (39.3%) | |
| Uncontrolled | 17 (31%) | 7 (46.6%) | 2 (7.1%) | ||
| Irregular | 16 (29%) | 3 (20%) | 15 (53.6%) | ||
| Nondiabetics | 3 (5.4%) | 1 (6.6%) | 0 | ||
| Eichenholtz stage (no. of patients) | Stage 1 | 7 (12.7%) | 0 | 1 (3.6%) | |
| Stage 2 | 30 (54.5%) | 4 (26.6%) | 22 (78.6%) | ||
| Stage 3 | 18 (32.7%) | 11 (73.3%) | 5 (17.9%) | ||
| Brodsky | Type 1 | 14 (25.4%) | 2 (13.3%) | 25 (89.3%) | |
| Type 2 | 21 (38.1%) | 0 | 0 | ||
| Type 1 + type 2 | 20 (36.3%) | 13 (86.6%) | 3 (10.7%) | ||
| ESR (mm/hour)† | 32.5 ± 33.9 | 44.7 ± 26.3 | – | ||
| CRP (mg/dL) † | 34.3 ± 25.2 | 53 ± 46.7 | – | ||
| Urea (mg/dL) † | 33 ± 17.4 | 35 ± 16.7 | – | ||
| Creatinine (mg%)† | 1.2 ± 0.5 | 1.3 ± 0.7 | – | ||
CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HbA1c, glycated hemoglobin; RBS, random blood sugar. Values are presented as † (mean ± SD), or number as % or *number of patients
| Outcomes | Orthopedic center-1 | Orthopedic center-2 | Orthopedic center-3 | |
|---|---|---|---|---|
| AOFAS scores† | Preoperative | 23 ± 2.77 | 64 ± 5.43 | 56.8 ± 5 |
| Final follow-up | 74.5 ± 13.5 | 69.5 ± 4.6 | 57.5 ± 4.8 | |
| p-value | 0.0005 (s) | 0.042 (s) | 0.18 (ns) | |
| FAOS scores† | Preoperative | 28 ± 3.8 | 62.9 ± 2.2 | – |
| Final follow-up | 83 ± 13.7 | 77.9 ± 4.9 | – | |
| p-value | 0.0005 (s) | 0.004 (s) | ||
| Union rates | Bony union in both columns | 21 (38.2%) | 7 (46.7%) | 22 (78.6%) |
| Fibrous union in both columns | 16 (29.1%) | 6 (40%) | – | |
| Stable union (bony + fibrous) | 15 (27.3%) (medial: 9, lateral: 6) | – | – | |
| Nonunion | 3 (5.4%) | 2 (13.3%) | 6 (21.4%) | |
| Meary’s angle† | Preoperative | 28.8 ± 8° | 16 ± 16° | 15 ± 4.5° |
| Final follow-up | 12.6 ± 7.8° | 10.5 ± 2.7° | 4.5 ± 2° | |
| p-value | 0.0005 (s) | >0.05 (ns) | >0.05 (ns) | |
| Meary’s angle† (Secondary collapse) | Immediate postoperative | 6.5 ± 2.7° | 7.8 ± 3.8° | – |
| Final follow-up | 12.6 ± 7.8° | 10.5 ± 2.7° | – | |
| p-value | 0.08 (ns) | 0.274 (ns) | – | |
| Talo-first metatarsal angle† (AP) | Preoperative | 16 ± 9° | 16 ± 12.6° | 6.8 ± 2.6° |
| Final follow-up | 8 ± 5.5° | 8.6 ± 8° | 3.9 ± 1.5° | |
| p-value | 0.0005 (s) | 0.3 (ns) | 0.0005 (s) | |
| Calcaneal pitch† | Preoperative | −2.8 ± 3.6° | 2.4 ± 4° | −1.46 ± 5.2° |
| Final follow-up | 6.2 ± 7.6° | 4.2 ± 3° | 14 ± 4.5° | |
| p-value | 0.042 (s) | 0.062 (ns) | 0.0005 (s) | |
| Cuboid height† (mm) | Preoperative | −5.1 ± 8.4 | −5.4 ± 0.6 | 0.03 ± 3.8 |
| Final follow-up | 4.8 ± 8.3 | 0.2 ± 0.4 | 6.8 ± 1.5 | |
| p-value | 0.0005 (s) | 0.053 (ns) | 0.0005 (s) | |
ns, not significant; s, significant. Values are presented as † mean ± SD or number as %
| Orthopedic center-1 | Orthopedic center-2 | Orthopedic center-3 | ||
|---|---|---|---|---|
| Overall complication | Minor complications# | 13 (23.6%) | 1 (6.6%) | 6 (21.4%) |
| Major complications## | 15 (27.2%) | 6 (40%) | 7 (25%) | |
| Total | 28 (50.9%) | 7 (46.7%) | 13 (46.4%) | |
| Infection | Superficial | 4 (7.2%) | 1 (6.6%) | 6 (21.4%) |
| Deep | 2 (3.6%) | 0 | 0 | |
| Implant failure | Major | 9 (16.3%) | 1 (6.6%) | 6 (21.4%) |
| Minor | 6 (10.9%) | 2 (13.3%) | 0 | |
| Ulcer | 3 (5.4%) | 0 | 0 | |
| Exostosis | 5 (9%) | 3 (20%) | 1 (3.5%) | |
| Amputation | 1 (1.8%) | 0 | 0 | |
Values are presented as numbers as %. #, minor complication (superficial infection, minor implant failures like screw back out, stable midfoot with implant breakage); ##, major complication (deep infection, major implant failure that required screw removal/amputation, ulcer, exostosis requiring exostectomy)
Orthopedic Center-1
A total of 21 out of 55 had a bony union in both columns, 31 out of 55 had fibrous union and the three of 55 remained ununited at a mean follow-up of 22 ± 3.8 months. Two out of the three nonunions required implant removal and exostectomy following implant failure (screw breakage and collapse). One patient had a persistent infection which remained uncontrolled with multiple debridement and required below-knee amputation.
The complication rate was 50.9% (28/55) including both minor (23.6%) (Fig. 6) and major (27.2%) complications. Five (9%) patients developed exostosis on the plantar aspect causing callosities. All five patients were offered exostectomy. Two out of three patients who had associated postoperative plantar ulcers were treated conservatively with vacuum-assisted closure (VAC) dressings and one patient required a fasciocutaneous flap for recalcitrant ulcer. Six (10.9%) patients had wound complications of which four were treated with IV antibiotics, and two patients who had deeper infections underwent debridement and implant removal. All four patients who were treated conservatively had clinically stable foot and uneventful follow-ups.
The most common implant failure encountered was beam screw breakage. Six patients who had fibrous union with screw breakage were managed conservatively. Three patients had associated infections where implant removal was warranted. We encountered six screw backouts after the collapse, which were removed under local anesthesia.
Orthopedic Center-2
Seven out of 15 had a bony union in both columns (Fig. 5), six out of 15 had a fibrous union, and two out of 15 remained ununited at a mean follow-up of 79.06 ± 12.19 months. In our series, the most frequent complications were delayed wound healing, scar dehiscence, nonunion, pseudoarthrosis, and implant failures. One of our patients had a loosening of the beam screw after reactivation of CN’s second attack, which affected the hindfoot. This was treated with TCC, and once the disease reached the consolidation stage, weight-bearing was initiated.
The complication rate was 46.6% (seven out of 15) including both minor and major complications. Three (20%) patients developed exostosis on the plantar aspect causing callosities. All three patients were given Charcot restraint orthotic walker (CROW) which was managed conservatively. One (6.6%) patient had a superficial wound infection and was treated with intravenous (IV) antibiotics. In a few cases, persistent oozing from sutured wounds was a common observation in these surgeries. This oozing persisted for >1 week. We began using vacuum-assisted dressings in cases where wound bleeding persisted for longer than 4–5 days. It was observed that complications such as delayed wound healing, scar dehiscence, and infections significantly decreased. A total of 17 out of 20 had VAC dressings.
The most common implant failure encountered was beam screw breakage at the TMT junction. Two patients who had fibrous union with screw breakage were managed conservatively. One patient had an associated infection where implant removal was warranted.
Orthopedic Center-3
The average follow-up at center-3 was 10.28 ± 1.90 months. The average duration of symptoms was 34.25 ± 12.44 months. There was no major difference considering the AOFAS scores, the mean final follow-up AOFAS score was 57.53 ± 4.86 compared to the mean preoperative score of 56.89 ± 5.01.
Around 22 out of 28 patients had a bony union in both columns and six out of 28 remained ununited at a mean follow-up of 22 ± 3.6 months.
The complication rate was 46.4% (13/28) including both minor (21.4%) and major (25%) complications. One (3.5%) patient who developed exostosis on the plantar aspect causing callosities, was managed with CROW conservatively. Six (21.4%) patients had superficial wound infection, which was managed with IV antibiotics.
The most common implant failure encountered was beam screw breakage. Six patients who had nonunion had screw breakage.
DISCUSSION
The goal of surgical management in CN is to provide an ulcer-free, infection-free, plantigrade osseous stable foot that can accommodate depth inlay therapeutic footwear and provide independent walking.18 Surgical management guidelines are lacking due to insufficient evidence and lack of prospective randomized control studies. However, surgical arthrodesis of the midfoot using plates, standard screws compression osteosynthesis, or intramedullary screws are the most commonly used techniques. The contemporary fixation device widely used in midfoot Charcot reconstruction is an intramedullary beam. In the presence of weak bones, the choice of the ideal technique and ideal implant becomes imperative. In our multicenter study, stable bony union was seen in 21 out of 55 (38%), seven out of 15 (46%), and 22 out of 28 (78.5%) patients in center-1, -2, and 3, respectively. Very few studies in the literature report union rates in terms of the fusion of single or both columns. Previously reported studies cite a relatively higher union rate of 84% after internal fixation with intramedullary beaming.10,19 Though the solid bony union was lower and varied across different centers, stable plantigrade ulcer-free foot complete bony union, stiff fibrous union and (bony + fibrous union) was seen in the majority of the patients and ranged between 78.5 and 95% (Table 2). This difference could have been due to the variation in the choice of the implant as well as the duration of final follow-up across the centers. There are no studies which report differential union of bony vs fibrous vs combined fibrous and bony union, and this is the first study to have looked into these important components of results after surgical stabilization of midfoot CN. Further, no additional fixation was needed in terms of the external fixation device due to the inherent strength of the fixation.
The improvement in midfoot AOFAS scores was evident across the centers, however, it was statistically significant in center-1 and -2 (p-value < 0.05). This finding corroborates with the results of Pakarinen et al., who reported a mean outcome of 80.7 in their cross-sectional long-term follow-up of 41 patients over 8 years.20 Eschler et al., reported a mean midfoot AOFAS score of 60 (SD ± 2.5) at an average follow-up of 4 years after medial and lateral column fusion.21 The FAOS scores reported in center-1 (p-value = 0.0005) and center-2 (p-value = 0.004) also showed significant improvement. However, Ford et al. in their analysis of 25 patients after intramedullary beam screw fixation highlighted that though functional scores improve as far as activities of daily living are concerned their physical ability to participate in recreational activities remains largely limited as reflected in the sports subscale of the functional scores.22
The typical deformity in CN is flatfoot with its apex at the midfoot (i.e., dorsal displacement of the forefoot with respect to the hindfoot) which corresponds to negative lateral TMT (Meary’s) angles. Various midfoot Charcot deformity patterns have been described and the proposed reconstructive techniques have been described in the past. The common pattern is the “rocker bottom and forefoot abduction” type. The patterns are dorsal “subluxation” and “forefoot adduction.”23 Among all radiological parameters Bevan and Tomlinson suggested that the lateral TMT (Meary’s) is the most important angle predictive of ulcer formation.24 The preoperative lateral TMT improved in all centers and it was statistically significant in center-1 (p-value = 0.0005) (Table 3). Calcaneal pitch also improved following arch restoration and was maintained till the final follow-up with values reaching statistical significance in both center-1 (p-value = 0.042) and center-3 (p-value = 0.0005). Regauer et al. in their study of 83 patients showed significant improvement in the lateral TMT and the calcaneal pitch postresection arthrodesis for midfoot CN.25 TMT angle in AP view is a marker for forefoot abduction and was significantly reduced in our series across all centers with statistically significant improvement in center-1 and -3 (p-value = 0.0005). Wukich et al. suggested that among the two columns, loss of lateral column integrity is more significantly associated with poor prognosis than the medial column.17 The cuboid height is an indirect measure of lateral column height that was improved in center-1 and -3 and was statistically significant (p-value = 0.005). Thus there was no significant incidence of loss of reduction in our study as suggested by the improved radiological parameters which contradicts the established literature where loss of reduction is a significant problem.26
Medial and lateral column fusion is a salvage procedure and is known to be associated with a high complication rate of up to 89% with a revision surgery rate of 46%.25 This was considerably lower in our study with a total complication rate varying between 46 and 51% across the three centers. The commonest wound complications were delayed wound healing and oozing from the wound. Center-2 have managed all 17 out of 20 patients with VAC dressing who had persistent serous discharge from the wound. This brought down the postoperative wound complication. There are very few studies on the role of VAC dressing in Charcot’s foot reconstruction postoperatively. VAC dressings can be included in postoperative Charcot’s foot management guidelines a good multicentric study. The most common complication encountered was screw breakage at the TMT junction. The reoperation rate was also considerably lower amounting to 27% (13 out of 55) in center-1, 7% (one out of 15) in center-2, and no reoperations in center-3. Only one patient (1.8%) in center-1 required amputation for recurrent infection despite multiple debridement which is contrary to established literature that reports higher rates (4%) of amputation.18,19,27
There is very little consensus in the literature regarding the optimal management of midfoot Charcot’s arthropathy. Based on our experience in managing midfoot CN, we divide the entire spectrum of presentation with midfoot CN as follows (Fig. 1). Firstly, midfoot Charcot presenting with a bony prominence and an ulcer requires a multidisciplinary approach with debridement and skin grafting/flap surgeries at the first stage followed by medial and lateral column fusion in the second stage. The second subset of patients presenting with midfoot CN with unstable medial and lateral columns require long stabilization with intramedullary beam screw fixation with an additional “superconstruct” to prevent midfoot collapse and skin ulceration. The concept of the superconstruct was first coined by Sammarco et al.10 and is based on four principles—(1) fusion is extended beyond the zone of bone destruction, bridging the destructed joints, (2) bone resection is necessary to shorten the column, to avoid overstretching of soft tissue and wound necrosis, (3) use of the strongest possible device that bones and soft tissue can tolerate, and (4) implant positioning that maximizes the mechanical function.10 Careful preoperative evaluation with an antibiotic cover and glycemic cover can further decrease the chances of postoperative infection and morbidity (Fig. 2). Also, it is imperative to delay surgery until the acute symptoms of CN resolve during which the foot can be immobilized using a TCC. The third subset of patients presenting with a stable medial and lateral column with a bony prominence (consolidated midfoot) require only exostectomy with or without tendo-Achilles lengthening.28 Primary amputation can be considered in midfoot CN with gross destruction of bones or with coexisting infection/osteomyelitis that constitutes the fourth subset of patients.27
Limitations of Study
There are a few shortcomings in this study, a relatively low case sample size, a missing control group, and a short follow-up time. However, Charcot’s neuropathy is not a common disorder, and hence, pooled data from multiple centers was utilized for the study. Varied presentation in midfoot CN leads to nonuniform treatment in the form of variable implants and techniques. The main limitation of this study is the wide variation in the treatment protocol, patient selection, surgical technique, and postoperative management between three different groups of patients included in this study. This may have contributed to the variation in the outcomes. The shorter follow-up in some centers reflects the patient group with poor compliance. However, for analysis of radiological and functional outcomes, a 2-year follow-up period seems sufficient.
CONCLUSION
Based on the observations in this study, early surgical intervention in midfoot Charcot’s arthropathy is recommended. Midfoot fusion with intramedullary beam screws with or without superconstruct results in acceptable bony union/fibrous union that provides a plantigrade stable foot despite complications like implant breakage, loss of fixation, and wound infections.
ORCID
Rajagopalakrishnan Ramakanth https://orcid.org/0000-0001-8288-9330
Abhishek Kini https://orcid.org/0000-0003-1511-1216
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