Polymethylmethacrylate (PMMA) Augmentation Enhances the Mechanical Characteristics of Midfoot Beam Constructs in Charcot Neuroarthropathy Cadaver Model.

BACKGROUND: Even with the best conservative care, patients with Charcot neuroarthropathy (CN) of the foot and ankle often ulcerate, increasing their risk of infection, amputation, and death. Surgical fixation has been associated with risk of recurrent ulceration, potentially due to poor bone quality prone to recurrent deformity and ulceration. We propose midfoot beam reconstruction with PMMA augmentation as a novel means of improving fixation. METHODS: A protocol was developed to create characteristic CN midfoot fragmentation both visually and fluoroscopically in each of 12 matched-pair cadaveric feet. Afterward, the pairs were divided into 2 groups: (1) midfoot beam fusion surgery alone, and (2) midfoot beam fusion surgery augmented with PMMA. A solid 7.0-mm beam was placed into the medial column and a solid 5.5-mm beam was placed across the lateral column. In the PMMA group, 8 to 10 mL of PMMA was inserted into the medial column. The hindfoot of each specimen was potted and the metatarsal heads were cyclically loaded for 1800 cycles, followed by load to failure while load and displacement were continually recorded. RESULTS: One specimen in the beam alone group failed before reaching the 1800th cycle and was not included in the failure analysis. The midfoot beam only group demonstrated greater mean displacement during cycle testing compared with the PMMA group, P < .05. The maximum force (N), stiffness (N/mm), and toughness (Nmm) were all significantly greater in the group augmented with PMMA, P < .05. CONCLUSION: In a CN cadaveric model, PMMA augmentation significantly decreased gapping during cyclic loading and nearly doubled the load to failure compared with midfoot beams alone. CLINICAL RELEVANCE: The results of this biomechanical study demonstrate that augmentation of midfoot beams with PMMA increases the strength and stiffness of the fusion construct. This increased mechanical toughness may help reduce the risk of nonunion and infection in patients with neuropathic midfoot collapse.

Infrared dermal thermometry is highly reliable in the assessment of patients with Charcot neuroarthropathy.

BACKGROUND: Charcot neuroarthropathy (Charcot foot) is a serious limb-threatening complication most commonly seen in individuals with diabetic peripheral neuropathy. Although dermal thermometry is widely used by clinicians to assist in the diagnosis, monitoring, and management of the disease, there is limited high-quality evidence to support its reliability. Therefore, this study investigated the intra-rater and inter-rater reliability of infrared dermal thermometry in patients with Charcot neuroarthropathy. METHODS: We collected clinical, demographic, health status, and foot examination information on 32 adults with Charcot neuroarthropathy from a metropolitan high-risk foot service in Melbourne, Australia. Infrared dermal thermometry assessments were conducted by two independent raters at 10 anatomical sites of the Charcot foot using both a (i) touch and (ii) non-touch technique. Intra-rater and inter-rater reliability of the two assessment techniques were evaluated using intra-class correlation coefficients (ICCs), limits of agreement, standard error of measurement, and minimal detectable change statistics. RESULTS: Mean age was 59.9 (standard deviation [SD], 10.5) years, 68.8% were male, average duration of diabetes was 20.6 (SD, 15.1) years, 71.9% had type 2 diabetes, 93.8% had peripheral neuropathy, 43.8% had peripheral arterial disease, and 50% had previous foot ulceration. Charcot foot most commonly affected the tarsometatarsal joints (38.9%), had a median duration of 2.8 (interquartile range [IQR], 1.3 to 5.9) months, and a large proportion were being treated with total contact casting (69.4%). Overall, there was good to excellent intra-rater and inter-rater relative reliability for the 'touch' technique (ICC, 0.87 to 0.99; ICC, 0.83 to 0.98, respectively), and excellent intra-rater and inter-rater relative reliability for the 'non-touch' technique (ICC, 0.93 to 0.99; ICC, 0.91 to 0.99, respectively). In addition, measurement error was found to be relatively low across the 10 anatomical sites. CONCLUSIONS: Infrared dermal thermometry can now be used with confidence in clinical and research settings to provide a reliable assessment of skin temperature in patients with Charcot neuroarthropathy, using either a touch or non-touch technique at 10 commonly used testing sites. A non-touch technique, however, was observed to have slightly higher reliability indicating it may be associated with less measurement error than the touch technique.

Mid-term walking ability after Charcot foot reconstruction using the Ilizarov ring fixator.

BACKGROUND: Failed conservative treatment and complications are indications for foot reconstruction in Charcot arthropathy. External fixation using the Ilizarov principles offers a one-stage procedure for deformity correction and resection of osteomyelitic bone. The aim of this study was to determine whether external fixation with an Ilizarov ring fixator leads reliably to walking ability. MATERIALS AND METHODS: 29 patients treated with an Ilizarov ring fixator for Charcot arthropathy were retrospectively analyzed. Radiologic fusion at final follow up was assessed separately on conventional X-rays by two authors. The association between walking ability and the presence of osteomyelitis at the time of reconstruction, and the presence of fusion at final follow up was investigated using Fisher's exact test. RESULTS: Mean follow up was 35 months (range 5.3-107) months; mean time of external fixation was 113 days. Ten patients (34.5%) reached fusion, but 19 did not (65.5%). Two patients needed below knee amputation. 26 of the remaining 27 patients maintained walking ability, 23 of those without assistive devices. Walking ability was independent from the presence of osteomyelitis at the time of reconstruction and from the presence of fusion. CONCLUSION: Foot reconstruction with an Ilizarov ring fixator led to limb salvage in 93%. The vast majority (96.3%) of patients with successful limb salvage was ambulatory, independent from radiologic fusion, and presence of osteomyelitis at the time of reconstruction. These findings encourage limb salvage and deformity correction in this difficult-to-treat disease, even with underlying osteomyelitis.

Heterotopic ossifications and Charcot joints: Congenital insensitivity to pain with anhidrosis (CIPA) and a novel NTRK1 gene mutation.

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV (HSAN-IV), is a rare and severe autosomal recessive disorder. We report on an adult female patient whose clinical findings during childhood were not recognized as CIPA. There was neither complete anhidrosis nor a recognizable sensitivity to heat. Tumorlike swellings of many joints and skeletal signs of Charcot neuropathy developed in adolescence which, together with a history of self-mutilation, led to a clinical suspicion of CIPA confirmed by identification of a novel homozygous variant c.1795G > T in the NTRK1 gene in blood lymphocytes. Both parents were heterozygous for the mutation. The variant predicts a premature stop codon (p.Gly599Ter) and thus represents a pathogenic variant; the first reported in the Southeastern European population.

Results of Simple Conservative Treatment of Midfoot Charcot Arthropathy.

BACKGROUND: Traditionally, conservative management with an offloading orthosis, such as total contact cast (TCC), has been the standard of care for midfoot Charcot arthropathy. Considering complications of TCC and surgery, we treated midfoot Charcot arthropathy without TCC in our patients. The purpose of this study was to report clinical and radiological outcomes of conservative management of midfoot Charcot arthropathy. METHODS: A total of 34 patients (38 feet) who were diagnosed as having midfoot Charcot arthropathy between 2006 and 2014 were included. Patients started full weight bearing ambulation in a hard-soled shoe immediately after diagnosis. Outcomes such as progression of arch collapse, bony prominence, ulcer occurrence, limb amputation, and changes in Charcot stage were evaluated. RESULTS: Of 38 feet, arch collapse was observed in four while progression of bottom bump of the midfoot was observed in five feet. Foot ulcers related to bony bumps were found in two feet. CONCLUSIONS: Conservative treatment without restriction of ambulation is recommended for midfoot Charcot arthropathy because it is rarely progressive, unlike hindfoot-ankle arthropathy. In some cases, simple bumpectomy can be required to prevent catastrophic infection.

Pressure distribution under the contralateral limb in Charcot arthropathy with different walking speeds.

BACKGROUND: The total contact cast has been recognized as the "gold standard" for treatment of Charcot neuro-osteoarthropathy (CN). However, removable cast walkers (RCWs) became an alternative option especially after resolution of the acute stage. RCWs with an elevated sole construction often induce leg length discrepancy (LLD) that could significantly affects plantar pressure (PP) distribution in diabetic patients with neuropathy. AIM: To study the additional effect of walking speed on PP abnormalities induced by LLD. METHOD: The study included 16 patients with diabetes (59±8.8years; 8 men and 8 women), with unilateral CN offloaded by RCW. In-shoe PP distribution was measured using F-scan (Tekscan Inc.), whilst patients walked at their normal speed (53±4 steps/min), versus short slow steps (24±3/min) under the two walking conditions: (1) neglected LLD, and (2) corrected LLD. RESULTS: The greatest reduction in PP was seen during reduction of walking speed, with corrected LLD, followed by corrected LLD with normal walking speed, followed by neglected LLD with slowing of walking speed. The highest PP was found when the patient remain on their normal walking speed and LLD was neglected. CONCLUSION: The contralateral foot of CN offloaded with RCW, is subjected to high pressure loads beneath the hallux, 1st, 2nd, 3rd, and 5th metatarsal heads. As such, care should be taken not only to avoid minor LLD, but to also advise the patient to practice short slow steps while walking, so that pressure overload on contralateral limb and its possible contribution to the development of bilateral Charcot, could be minimized.

Deformity and Clinical Outcomes Following Operative Correction of Charcot Ankle.

BACKGROUND:: Deformity associated with Charcot foot arthropathy leads to a poor quality of life in affected individuals. Deformity in the midfoot appears to be predictive of clinical outcomes following operative correction. The goal of this retrospective study was to determine if that same methodology could be applied to patients treated for Charcot foot arthropathy involving the ankle joint. METHODS:: Fifty-six consecutive patients underwent operative reconstruction of Charcot foot deformity involving the ankle joint by a single surgeon over a 14-year period. Preoperative patient characteristics and tibiotalar alignment, were recorded. Surgical treatment included single-stage debridement of active infection and ankle arthrodesis with application of a circular external fixator when infection was present (39 of 56, 69.6%) or retrograde locked intramedullary nailing in the absence of infection (17 of 56, 30.3%). Clinical outcomes were graded based on limb salvage, resolution of infection and chronic wounds, and the ability to ambulate with therapeutic footwear or accommodative orthoses. The average follow-up was 7.5 (range 1.1-14.0) years. RESULTS:: One patient died at 134.3 weeks following surgery of unrelated causes and 8 underwent amputation. Twenty-eight of 56 patients (50.0%) achieved a favorable (excellent or good) clinical outcome. There was no significant association between pre- or postoperative alignment and clinical outcomes. Insulin-dependent diabetics were approximately 3 times more likely to have a poor clinical outcome. CONCLUSIONS:: Operative correction of Charcot deformity involving the ankle joint was associated with a high complication rate and risk for failure. The lessons learned from this highly comorbid patient population with complex deformities can be used as a benchmark for applying modern surgical techniques. LEVEL OF EVIDENCE:: Level IV, case series.

Defect Reconstruction of an Infected Diabetic Foot Using Split- and Full-thickness Skin Grafts With Adjuvant Negative Pressure Wound Therapy: A Case Report and Review of the Literature.

INTRODUCTION: Any alteration or impairment to normal wound healing can result in the development of chronic wounds, which may lead to serious complications such as infection and loss of body fluid and proteins. Primary closure alone may not be sufficient to fulfill the criteria of successful defect reconstruction. Therefore, additional procedures such as skin grafting must be considered as an option. CASE REPORT: The case of a 43-year-old woman with diabetes who was admitted to the University Hospital Rebro (Zagreb, Croatia) due to an infected, nonhealing wound on her left foot. Skin grafts combined with negative pressure wound therapy (NPWT) before and after graft application improved wound healing in this patient. CONCLUSIONS: In this patient, the combination of skin grafts with NPWT before and after graft application reduced the comorbidities and complications often seen in the diabetic patient population. Herein, the authors utilized a quicker, cost-efficient, and safer technique of wound closure compared with traditional nonsurgical methods.

Markers of Local Inflammation and Bone Resorption in the Acute Diabetic Charcot Foot.

OBJECTIVE: Due to the localized nature of Charcot foot, systemically altered levels of inflammation markers can be difficult to measure. The aim of this study was to investigate whether it is possible to detect an arteriovenous (A-V) flux in any locally produced inflammatory biomarkers from an acute Charcot foot by comparing local and systemic measurements. METHODS: We included patients with acute diabetic Charcot foot. Blood was sampled from the vena saphena magna on the distal part of the crus bilaterally as well as from the arteria radialis. To minimize the A-V shunting effect, the feet were externally cooled with ice water prior to resampling. RESULTS: Both before and after cooling, the A-V flux of interleukin-6 (IL-6) between the Charcot feet and the arterial level was significantly higher than the flux between the healthy feet and the arterial level (Δvaluebefore: 7.25 versus 0.41 pg/mL, resp., p = 0.008; Δvalueafter: 10.04 versus 1.68 pg/mL, resp., p = 0.032). There were no differences in the fluxes for other markers of inflammation. CONCLUSION: We have found an increased A-V flux of IL-6 in the acute diabetic Charcot foot compared to the healthy foot in the same patients.

Neuropathic Arthropathy of the Glenohumeral Joint A Review of the Literature.

Neuropathic arthropathy, also known as Charcot arthropathy, is a degenerative disorder most commonly characterized by rapid destruction of the joint with extensive involvement of the bone and soft tissue. The underlying pathophysiology is thought to be due to loss of nociception (pain sensation), most frequently caused by diabetes mellitus, syphilitic myelopathy, or syringomyelia. A neuropathic shoulder is rare, with historic case series forming the bulk of the literature. The purpose of this review is to better understand the pathogenesis, clinical presentation, and management of neuropathic arthropathy of the glenohumeral joint. It should be stressed that the identification and management of the underlying etiology is paramount if the disease process is to be positively impacted. Although the mainstay of orthopedic management is non-surgical, little evidence exists to support the use of any specific therapeutic intervention. Recent literature suggests surgical reconstruction may be considered in very select patients.

Charcot Foot: Clinical Clues, Diagnostic Strategies, and Treatment Principles.

Acute Charcot neuroarthropathy of the foot and ankle is often difficult to diagnose because of limited findings in the patient history, physical examination, imaging, and laboratory studies. Delay in treatment results in the development of rigid foot and ankle deformities, increasing the risk of ulceration, infection, and major lower extremity amputation. Acute Charcot neuroarthropathy should be suspected in any patient 40 years or older with obesity and peripheral neuropathy who presents with an acutely swollen foot following minimal or no recalled trauma and who reports minimal to no pain, particularly if radiography and laboratory markers of infection are normal. Magnetic resonance imaging or computed tomography should be performed in these cases. If changes consistent with acute Charcot neuroarthropathy are observed, prompt immobilization and/or referral to a foot and ankle subspecialist is needed to minimize sequelae. Immobilization should continue until lower extremity edema and warmth resolve, and serial radiography shows evidence of osseous consolidation. Intranasal calcitonin salmon may have a role as adjunctive therapy. Although controversial, surgery may be indicated if there is severe dislocation or instability, concern for skin breakdown, or failure of conservative treatment to obtain a stable, plantigrade foot.

Improvement in Quality of Life Following Operative Correction of Midtarsal Charcot Foot Deformity.

BACKGROUND: Patients with Charcot foot arthropathy report a poor quality of life following the development of deformity. Their quality of life is often not improved with "successful" historic accommodative treatment. There is increased current interest in operative correction of the acquired deformity with the stated goals of achieving both the traditional goals of resolution of infection and limb salvage as well as the desire to improve quality of life. The Short Musculoskeletal Functional Assessment (SMFA) outcomes instrument appears to be a valid tool for evaluating this complex patient population. METHODS: Twenty-five consecutive patients undergoing operative reconstruction for nonplantigrade midtarsal Charcot foot arthropathy completed the SMFA patient-reported outcomes instrument prior to surgery, with 24 completing it at 1 year following the surgery. One patient died during the year following surgery from unrelated causes. RESULTS: There was an 11.5-point (95% confidence interval [CI]: -19.7 to -3.2) decrease in the standardized functional index ( P = .01). Similarly, there was a 12.4-point (95% CI: -22.5 to -2.3) decrease in the standardized bother index ( P = .02). The standardized daily activity index demonstrated a 19.6-point decrease (95% CI: -30.5 to -8.6, P = .002), and there was a 14.7-point (95% CI: -24.1 to -5.3) decrease in the standardized emotion index ( P = .004). There was no meaningful change in the standardized arm/hand index ( P = .81). CONCLUSION: The results of this investigation demonstrate that successful operative reconstruction of midtarsal Charcot foot arthropathy improved quality of life. This supports the modern paradigm shift from immobilization during the active phase of the disease process followed by simple accommodation of the acquired deformity to the modern interest in operative correction to allow the use of commercially available therapeutic footwear. LEVEL OF EVIDENCE: Level IV, case series.

Treating Charcot Arthropathy Is a Challenge: Explaining Why My Treatment Algorithm Has Changed.

Charcot deformity is a challenge that foot and ankle surgeons struggle to manage successfully. Despite the advances in knowledge, technology, and treatment modalities, limb loss is still greater than 10%. This article discusses the efficacy of conservative measures and traditional surgical approaches. It proposes a multidisciplinary team approach, medical optimization, and lifestyle modification to put the patient in the best position to heal. Also discussed is the authors' staged surgical treatment protocol to enhance outcomes and decrease the rate of limb loss.

Osteomyelitis of the lower extremity: pathophysiology, imaging, and classification, with an emphasis on diabetic foot infection.

Osteomyelitis is inflammation of the bone caused by an infectious organism, and is a difficult clinical problem. The pathophysiology, imaging, and classification of osteomyelitis are challenging, varying with the age of the patient (child versus adult), the chronicity of the infection (acute versus chronic), and the route of spread (hematogenous versus contiguous focus), as well as the immune and vascular status of the patient and affected region. The two most common classification schemes are those of Lew and Waldvogel, and Cierny and Mader. Brodie's abscess is seen in subacute osteomyelitis, while sequestrum, involucrum, and cloaca are inter-related entities of chronic osteomyelitis. Imaging workup of suspected osteomyelitis should begin with radiographs, although MRI is the most accurate imaging test. Three patterns of T1 signal change have been described in the setting of suspected osteomyelitis including confluent intramedullary, hazy reticular, and subcortical. The confluent intramedullary pattern is most associated with osteomyelitis, while hazy reticular is rarely associated with hematogenous osteomyelitis, and subcortical is not associated with osteomyelitis. It can be challenging to differentiate neuropathic arthropathy from osteomyelitis. Osteomyelitis tends to involve a single bone subjacent to an ulcer or sinus tract. In contrast, neuropathic arthropathy tends to involve multiple bones of the midfoot. Subchondral cystic change, thin rim enhancement of a joint effusion, and the presence of intra-articular bodies are more indicative of a neuropathic joint without infection. Biopsy can play an important role in diagnosis and treatment of osteomyelitis.

Bone mineral density and markers of bone turnover and inflammation in diabetes patients with or without a Charcot foot: An 8.5-year prospective case-control study.

BACKGROUND AND AIMS: Charcot foot is a rare but severe complication to diabetes and peripheral neuropathy. It is still unclear if an acute Charcot foot has long-term effects on the bone metabolism. To investigate this, we conducted a follow-up study to examine if a previously acute Charcot foot has any long-term effects on bone mineral density (BMD) or local or systemic bone metabolism. METHODS: An 8.5-year follow-up case-control study of 44 individuals with diabetes mellitus, 24 of whom also had acute or chronic Charcot foot at the baseline visit in 2005-2007, who were followed up in 2015 with DXA scans and blood samples. RESULTS: 21 of the 44 baseline participants participated in the follow-up. There were no difference in the change in total hip BMD from baseline to follow-up in either the Charcot or the control group (p = 0.402 and 0.517), and no increased risk of osteoporosis in the previous Charcot feet either. From baseline to follow-up, there was a significant difference in the change in levels of fsRANK-L in the Charcot group, but not in the control group (p = 0.002 and 0.232, respectively). At follow-up, there were no differences in fsRANK-L between the groups. The fsRANK-L/OPG ratio also significantly decreased from baseline to follow-up in the Charcot group (3.4 versus 0.5) (p = 0.009), but not in the control group (1.3 versus 1.1) (p = 0.302). CONCLUSION: We found that diabetes patients with an acute Charcot foot have an elevated fsRANK-L/OPG ratio, and that the level decreased from baseline to follow-up to be comparable to the level in diabetes patients without previous or current Charcot foot. We found no permanent effect of an acute Charcot foot on hip or foot BMD.

A retrospective audit of the characteristics and treatment outcomes in patients with diabetes-related charcot neuropathic osteoarthropathy.

AIMS: To review the characteristics, management and outcomes one year after diagnosis in patients with diabetes related charcot neuropathic osteoarthropathy (CN) treated at the Diabetes Podiatry service, Waitemata District Health Board (WDHB) between 2000-2014. METHODS: Patients with diabetes and recorded diagnosis of CN were identified from the podiatry service records. Clinical details were retrospectively obtained from WDHB databases and patient medical records. RESULTS: Forty-one patients were included, 31 had type 2 diabetes, 10 had type 1 diabetes. At presentation, the median duration of all-type diabetes was 15 years. The median time from symptom onset to diagnosis was 17 weeks. Symptoms at presentation were: oedema (49%), warmth (73%), erythema (17%), swelling (90%) and pain (60%). Concomitant ulcers were present in 32%, deformities 83%, osteomyelitis 2% and septic arthritis 2%. Mean time to ambulation in modified shoes was 21.3 weeks (±11.5). Complication rates one year from diagnosis for ulcers, osteomyelitis, amputations and all-cause mortality were 34%, 2%, 2% and 5% respectively. CONCLUSION: Time to diagnosis of CN was shorter than previously reported, though the high rate of deformities still suggests a significant delay in diagnosis. Increased education of healthcare professionals and people with diabetes-related neuropathy is important to ensure early diagnosis and appropriate management to reduce deformities and complications.

Pathogenesis and potential relative risk factors of diabetic neuropathic osteoarthropathy.

Diabetic neuropathic osteoarthropathy (DNOAP) is an uncommon, but with considerable morbidity and mortality rates, complication of diabetes. The real pathogenesis is still unclear. The two popular theories are the neuro-vascular theory and neuro-traumatic theory. Most theories and pathways focused on the uncontrolled inflammations that resulted in the final common pathway, receptor activator of nuclear factor κß ligand (RANKL)/osteoprotegerin (OPG) axis, for the decreased bone density in DNOAP with an osteoclast and osteoblast imbalance. However, the RANKL/OPG pathway does not explain all the changes, other pathways and factors also play roles. A lot of DNOAP potential relative risk factors were evaluated and reported in the literature, including age, gender, weight, duration and type of diabetes, bone mineral density, peripheral neuropathy and arterial disease, trauma history, and some others. However, most of them are still in debates. Future studies focus on the pathogenesis of DNOAP are still needed, especially for the genetic factors. And, the relationship between DNOAP and those potential relative risk factors are still need to further clarify.