The Charcot Foot Reflects a Response to Injury That Is Critically Distorted by Preexisting Nerve Damage: An Imperfect Storm

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.

Effect of denosumab on inflammation and bone health in active Charcot foot: A phase II randomised controlled trial

AIMS

We aimed to investigate the effect of denosumab on pedal bone health and clinical resolution in active Charcot foot (CN).

METHODS

This multicentre open-label phase 2 randomised controlled trial recruited adults with diabetes mellitus and active CN within 3 months of onset. Participants were randomised to standard care alone, or with denosumab 60 mg subcutaneously. Denosumab was administered at baseline and again at 6 months, unless foot temperature had normalised (i.e. <2 °C compared to contralateral foot). Co-primary outcomes were change in calcaneal Stiffness Index and foot temperature normalisation over 18 months.

RESULTS

Twelve participants per group were analysed; mean age 58 ± 11 years, 83 % male and 92 % had type 2 diabetes. Active CN duration was median 8 (IQR 7-12) weeks. Ninety-two percent were Eichenholtz stage 1 and 96 % involved the midfoot. After 1-month, median decline in Stiffness Index was less in the denosumab verses standard care group (0.5 [IQR -1.0 to 3.9] vs -2.8 [-8.5 to -1.0], p = 0.008). At 18-months, 92 % of the denosumab group attained foot temperature normalisation versus 67 % of the standard care group (p = 0.13).

CONCLUSIONS

Denosumab ameliorated the early decline in calcaneal Stiffness Index associated with active CN. However, no difference in normalisation of foot temperature was observed.

Charcot Foot Offloading in Stage 0 Is Associated With Shorter Total Contact Cast Treatment and Lower Risk of Recurrence and Reconstructive Surgery: A Pilot Study

OBJECTIVE

Charcot foot (CF) requires prolonged offloading of the affected foot to decrease the risk of deformity. The earliest phase in active CF (stage 0) is characterized by inflammatory signs without established fractures or skeletal deformity. We investigated whether offloading in stage 0 influences duration of total contact casting (TCC), risk of recurrence, and future need for surgery.

RESEARCH DESIGN AND METHODS

All patients treated for active CF at Skåne University Hospital (Lund, Sweden) between 2006 and 2019 were screened for participation in a retrospective cohort study. CF events of included patients were classified as stage 0 or 1 according to X-ray and MRI reports.

RESULTS

A total of 183 individuals (median age 61 [interquartile range (IQR) 52-68] years, 37% type 1 diabetes, 62% men) were followed for a median of 7.0 (IQR 3.9-11) years. In 198 analyzed CF events, 74 were treated with offloading in stage 0 and 124 in stage 1. Individuals offloading in stage 0 had significantly shorter TCC duration (median 75 [IQR 51-136] vs. 111.5 [72-158] days; P = 0.001). The difference was sustained when including only MRI-confirmed CF. The risk of developing new ipsilateral CF events >1 year after introduced definitive footwear was lower in those treated with offloading in stage 0 (2.7% vs. 9.7%; P < 0.05). No individual treated with offloading in stage 0 underwent reconstructive surgery, compared with 11 (8.9%) treated with offloading in stage 1 (P < 0.01). Amputation rates were similar.

CONCLUSIONS

Offloading in stage 0 CF was associated with shorter TCC treatment, lower risk of a new CF event, and diminished need for reconstructive surgery. Future amputation risk was not affected.

Orthopaedic Eponyms: A Tool of the Past

Eponyms are commonplace in the medical vernacular, however, their use has become increasingly controversial amongst clinicians. Whilst some view them as an honour bestowed on those whose achievements deserve recognition, others see them as thwarted with problems due to confusion, imprecision and unwittingly applauding controversial figures. Nevertheless, the history and culture retained within eponyms define modern-day medicine. To identify current trends in understanding of eponyms, we presented a questionnaire of orthopaedic eponyms and their associated imaging to unspecialised trainees, specialist orthopaedic trainees, and qualified consultants. Eponymous terms were poorly understood at all levels of experience, with- third and fourth-year Orthopaedic trainees (specialist trainee years five and six (ST5/ST6)) being outperformed (22.3%) by non-specialist postgraduate doctors with two or more years of experience (foundation year two (F2) and core surgery year two (CT2)) (29.3%). Based on these trends we present a further narrative review of the challenges eponyms present, whilst justifying their continued use to acknowledge the origins of our discipline, from the favourable to shameful.

The foot in diabetes - a reminder of an ever-present risk

The term 'diabetic foot disease' (DFD) often signifies the presence of foot ulceration and infection, but one must also be wary of the rarer occurrence of Charcot foot disease. The worldwide prevalence of DFD is 6.3% (95%CI: 5.4-7.3%). Foot complications present a major challenge to both patients and healthcare systems, with increased rates of hospitalisation and an almost trebled 5-year mortality. The Charcot foot often occurs in patients with long-standing diabetes, presenting as an inflamed or swollen foot or ankle, following unrecognised minor trauma. This review focuses on the prevention and early identification of the 'at-risk' foot. DFD is best managed by a multi-disciplinary foot clinic team consisting of podiatrists and healthcare professionals. This ensures a combination of expertise and provision of a multi-faceted evidence-based treatment plan. Current research using endothelial progenitor cells (EPC) and mesenchymal stem cells (MSC) offers a new dimension in wound management.

Controversies in the management of active Charcot neuroarthropathy

Charcot neuroarthropathy (CN) was first described over 150 years ago. Despite this there remains uncertanity around the factors that contribute to its development, and progression. This article will discuss the current controversies around the pathogenesis, epidemiology, diagnosis, assessment and management of the condition. The exact pathogenesis of CN is not fully understood, and it is likely to be multifactorial, with perhaps currently unknown mechanisms contributing to its development. Further studies are needed to examine opportunities to help screen for and diagnose CN. As a result of many of these factors, the true prevalence of CN is still largely unknown. Almost all of the recommendations for the assessment and treatment of CN are based on low-quality level III and IV evidence. Despite recommendations to offer people with CN nonremovable devices, currently only 40-50% people are treated with this type of device. Evidence is also lacking about the optimal duration of treatment; reported outcomes range from 3 months to more than a year. The reason for this variation is not entirely clear. A lack of standardised definitions for diagnosis, remission and relapse, heterogeneity of populations, different management approaches, monitoring techniques with unknown diagnostic precision and variation in follow-up times prevent meaningful comparison of outcome data. If people can be better supported to manage the emotional and physical consequences of CN, then this could improve people's quality of life and well-being. Finally, we highlight the need for an internationally coordinated approach to research in CN.