New Concepts in the Management of Charcot Neuroarthropathy in Diabetes

Assessment of bone marrow edema on dual-energy CT scans in people with diabetes mellitus and suspected Charcot neuro-osteoarthropathy

OBJECTIVE

This study aimed to quantitatively assess the diagnostic value of bone marrow edema (BME) detection on virtual non-calcium (VNCa) images calculated from dual-energy CT (DECT) in people with diabetes mellitus and suspected Charcot neuro-osteoarthropathy (CN).

MATERIALS AND METHODS

People with diabetes mellitus and suspected CN who underwent DECT of the feet (80kVp/Sn150kVp) were included retrospectively. Two blinded observers independently measured CT values on VNCa images using circular regions of interest in five locations in the midfoot (cuneiforms, cuboid and navicular) and the calcaneus of the contralateral or (if one foot was available) the ipsilateral foot. Two clinical groups were formed, one with active CN and one without active CN (no-CN), based on the clinical diagnosis.

RESULTS

Thirty-two people with diabetes mellitus and suspected CN were included. Eleven had clinically active CN. The mean CT value in the midfoot was significantly higher in the CN group (-55.6 ± 18.7 HU) compared to the no-CN group (-94.4 ± 23.5 HU; p < 0.001). In the CN group, the difference in CT value between the midfoot and calcaneus was statistically significant (p = 0.003); this was not the case in the no-CN group (p = 0.357). The overall observer agreement was good for the midfoot (ICC = 0.804) and moderate for the calcaneus (ICC = 0.712). Sensitivity was 100.0% and specificity was 71.4% using a cutoff value of -87.6 HU.

CONCLUSION

The detection of BME on VNCa images has a potential value in people with diabetes mellitus and suspected active CN.

Surgical management of Charcot foot - The advancements over the past decade

Charcot neuroarthropathy is a progressive, destructive condition leading to deformity, dysfunction and, in some cases, amputation. Much evolution has occurred over the last couple of decades in the management of Charcot foot with a focus on developing limb salvage and reconstructive techniques. The aim has been to achieve a stable plantigrade foot that remains pain and ulcer-free whilst reducing amputation rates. Soft tissue and bony reconstructions have been explored, and various modalities of fixation, including internal, external, and combined techniques, have been described and their outcomes published. Currently, no strong evidence exists which supports a particular modality of treatment, nor have there been any randomised studies to this effect, but the results are nevertheless promising. Recent studies have reported on minimally invasive techniques, the use of super construct fixation, computer-navigated deformity correction, the efficacy of techniques such as subtalar arthrodesis or tendon balancing procedures and staged deformity corrections. There is a need for more controlled and comparative studies with consistent reporting of intended outcomes to create a stronger portfolio of evidence on the surgical management of Charcot foot.

Cartilage Damage Pathological Characteristics of Diabetic Neuropathic Osteoarthropathy

Background

Diabetic neuropathic osteoarthropathy (DNOAP) is a rare and easily missed complication for diabetes that leads to increased morbidity and mortality. DNOAP is characterized by progressive destruction of bone and joint, but its pathogenesis remains elusive. We herein aimed to investigate the pathological features and pathogenesis of the cartilages damage in DNOAP patients.

Methods

The articular cartilages of eight patients with DNOAP and eight normal controls were included. Masson staining and safranine O/fixed green staining (S-O) were used to observe the histopathological characteristics of cartilage. The ultrastructure and morphology of chondrocytes were detected by electron microscopy and toluidine blue staining. Chondrocytes were isolated from DNOAP group and control group. The expression of receptor activator of nuclear factor kappaB ligand (RANKL), osteoprotegerin (OPG), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and Aggrecan protein was evaluated by western blot. Reactive oxygen species (ROS) levels were measured using a 2',7'-dichlorofluorescin diacetate (DCFH-DA) probe. The percentage of apoptotic cells was determined by flow cytometry (FCM). The chondrocytes were cultured with different glucose concentrations to observe the expression of RANKL and OPG.

Results

Compared with the control group, the DNOAP group showed fewer chondrocytes, subchondral bone hyperplasia, and structural disorder, and a large number of osteoclasts formed in the subchondral bone area. Moreover, mitochondrial and endoplasmic reticulum swellings were observed in the DNOAP chondrocytes. The chromatin was partially broken and concentrated at the edge of nuclear membrane. The ROS fluorescence intensity of chondrocyte in DNOAP group was higher than that in normal control group (28.1 ± 2.3 vs. 11.9 ± 0.7; P < 0.05). The expression of RANKL, TNF-α, IL-1β, and IL-6 protein in DNOAP group was higher than that in normal control group, whereas OPG and Aggrecan protein were lower than that in normal control group (both P < 0.05). FCM showed that the apoptotic rate of chondrocyte in DNOAP group was higher than that in normal control group (P < 0.05). The RANKL/OPG ratio showed significant upward trend when the concentration of glucose was over than 15 mM.

Conclusions

DNOAP patients tend to have severe destruction of articular cartilage and collapse of organelle structure including mitochondrion and endoplasm reticulum. Indicators of bone metabolism (RANKL and OPG) and inflammatory cytokines (IL-1β, IL-6, and TNF-α) play an important role in promoting the pathogenesis of DNOAP. The glucose concentration higher than 15 mM made the RANKL/OPG ratio change rapidly.

Diabetes Mellitus: An Overview in Relationship to Charcot Neuroarthropathy

Diabetes mellitus with the lack of glycemic control increases risks for developing comorbidities affecting organ systems responsible for critical function. The development of diabetic neuropathy predisposes patients to the onset of Charcot neuroarthropathy (CN). There is significant complexity with treatment of diabetic-induced CN, which can have an often delayed or missed diagnosis. Supervision and treatment from trained specialists are required to provide care for this multifaceted disease process. It is essential for patients to partner with glucose control, comorbidity prevention and care, as well as lower extremity management. Ultimately, CN can result in significant lower extremity deformity placing patients at risk of limb and life.

Nonoperative Treatment of Charcot Neuro-osteoarthropathy

Conservative treatment of Charcot neuro-osteoarthropathy (CN) aims to retain a stable, plantigrade, and ulcer-free foot, or to prevent progression of an already existing deformity. CN is treated with offloading in a total contact cast as long as CN activity is present. Transition to inactive CN is monitored by the resolution of clinical activity signs and by resolution of bony edema in MRI. Fitting of orthopedic depth insoles, orthopedic shoes, or ankle-foot orthosis should follow immediately after offloading has ended to prevent CN reactivation or ulcer development.

Foot ulcer recurrence, plantar pressure and footwear adherence in people with diabetes and Charcot midfoot deformity: A cohort analysis

AIMS

To investigate people with Charcot midfoot deformity with regard to plantar pressure, footwear adherence and plantar foot ulcer recurrence.

METHODS

Twenty people with diabetes, Charcot midfoot deformity, plantar foot ulcer history and custom-made footwear were assessed with regard to barefoot and in-shoe plantar pressures during walking, footwear adherence (% of daily steps over 7-day period) and plantar foot ulcer recurrence over 18 months. In a cohort design, they were compared to 118 people without Charcot foot (non-Charcot foot group) with custom-made footwear and similar ulcer risk factors.

RESULTS

Median (interquartile range) barefoot midfoot peak pressures were significantly higher in the Charcot foot group than in the non-Charcot foot group [756 (260-1267) vs 146 (100-208) kPa; P<0.001]. In-shoe midfoot peak pressures were not significantly higher in the Charcot foot group [median (interquartile range) 152 (104-201) vs 119 (94-160) kPa] and significantly lower for all other foot regions. Participants in the Charcot foot group were significantly more adherent, especially at home, than participants in the non-Charcot foot group [median (interquartile range) 94.4 (85.4-95.0)% vs. 64.3 (25.4-85.7)%; P=0.001]. Ulcers recurred in 40% of the Charcot foot group and in 47% of the non-Charcot foot group (P=0.63); midfoot ulcers recurred significantly more in the Charcot foot group (4/8) than in the non-Charcot foot group (1/55; P=0.001).

CONCLUSIONS

Effective offloading and very high footwear adherence were found in people with diabetes and Charcot midfoot deformity. While this may help protect against plantar foot ulcer recurrence, a large proportion of such people still experience ulcer recurrence. Further improvements in adherence and custom-made footwear design may be required to improve clinical outcome.