Charcot joint arthropathy is a progressive degenerative condition where neuropathy causes joint destruction, deformity and instability. Although most frequent in the foot and ankle, knee involvement occurs occasionally with rapid, disabling progression. Diagnosis is often challenging due to overlap with septic and inflammatory arthritis. We report a woman in her forties with post-spinal anaesthesia neuropathy who developed progressive left knee pain, deformity and instability over 5 years. Radiographs and MRI confirmed Charcot arthropathy. She successfully underwent total knee arthroplasty (TKA) using a tibial stem and autologous bone grafting. At 2 years postoperatively, she achieved pain-free mobility, excellent function and radiographic implant stability. This case highlights diagnostic considerations and underscores TKA as a viable reconstructive option in selected patients.

Lumbar facet synovial cysts (LFSCs) are degenerative lesions associated with facet arthropathy and segmental instability, predominantly occurring at the L4-L5 level. They may cause radiculopathy and neurogenic claudication, and although conservative management may provide temporary relief, cases associated with degenerative spondylolisthesis (DS) frequently require surgical treatment. Minimally invasive spine surgery assisted by spinal navigation allows precise cyst resection and adequate stabilization. The aim of this study was to present a case series of LFSCs associated with DS treated with navigation-assisted minimally invasive transforaminal lumbar interbody fusion and to describe the surgical technique and role of spinal neuronavigation in minimally invasive decompression and instrumentation. We report a series of three patients with symptomatic LFSCs associated with DS refractory to conservative treatment. All patients were evaluated using magnetic resonance imaging and dynamic radiographs and were treated with cyst resection, neural decompression, and percutaneous instrumentation assisted by neuronavigation. All patients demonstrated significant clinical improvement following surgical treatment, with reduction of radicular pain and functional improvement during postoperative follow-up. Most cases were associated with DS and advanced facet arthropathy changes. Neuronavigation allowed precise cyst resection with adequate neural decompression and preservation of posterior bony structures, without major complications or early recurrence during follow-up. LFSCs are closely associated with lumbar degenerative instability, and navigation-assisted resection represents a safe and effective minimally invasive alternative allowing adequate decompression while preserving spinal anatomy. Modern minimally invasive techniques and interventional therapies are emerging as complementary options in selected patients.

Charcot foot (CF) is a severe, progressive neuro-osteoarthropathy predominantly affecting diabetic patients with peripheral neuropathy. Characterized by progressive bone and joint destruction, CF can lead to debilitating foot deformities, ulceration, infection, and ultimately lower extremity amputation. Despite its significant clinical impact, the global prevalence remains uncertain, with an estimated 1.6 million people affected worldwide. Early diagnosis is challenging due to the insidious onset and limited specificity of current clinical, imaging, and laboratory assessments. The role of circulating metabolites in CF pathogenesis remains poorly understood. This study aimed to investigate the causal relationship between plasma metabolites and CF risk using Mendelian randomization (MR) and to identify potential biomarkers for early detection and therapeutic intervention. We conducted a bidirectional 2-sample MR study using genome-wide association study summary data. Plasma metabolite data were obtained from a cohort of approximately 8000 individuals of European descent (genome-wide association study catalog: GCST90199621-GCST90201020), and CF summary statistics were derived from the FinnGen Study (9th version), comprising 473 cases and 271,817 controls. Genetic instrumental variables were selected through linkage disequilibrium clumping and harmonization. The inverse-variance weighted method served as the primary analysis, supplemented by MR-Egger, weighted median, and weighted mode methods. Sensitivity analyses included Cochran Q test, Egger intercept test, MR-Pleiotropy RESidual Sum and Outlier, and leave-one-out analyses. Multivariable MR and colocalization analyses were performed to validate the findings. After false discovery rate adjustment, octadecadienedioate demonstrated a significant negative association with CF risk (odds ratio = 0.644, 95% confidence interval 0.528-0.785, false discovery rate = 0.018). This protective association was consistent across all MR methods, robust in sensitivity analyses, and further supported by multivariable MR (odds ratio = 0.632, 95% confidence interval 0.479-0.834) and colocalization analysis (posterior probability 4 = 0.945). Reverse MR analysis revealed no significant causal effects from CF to metabolite levels. Our findings identify octadecadienedioate as a novel protective factor against CF, highlighting the potential of circulating metabolites in understanding CF pathogenesis. These results may inform future preventive strategies, biomarker development, and personalized diabetic foot care.

BACKGROUND Charcot neuroarthropathy (CN) is a rare and easily misdiagnosed neuropathic arthropathy, often secondary to conditions such as syringomyelia and diabetes mellitus. Its clinical course is insidious, making early diagnosis challenging, and the presence of infection further complicates management. CASE REPORT This article reports a case of a 48-year-old male patient with elbow CN and secondary infection due to syringomyelia. The patient presented with swelling, erythema, and elevated skin temperature of the left elbow, but without significant pain. Imaging studies revealed elbow dislocation accompanied by extensive bony destruction. Laboratory test results showed a markedly elevated high-sensitivity C-reactive protein level (62.10 mg/L), and bacterial culture identified Staphylococcus aureus infection. After thorough debridement, the patient was treated with vacuum sealing drainage (VSD) combined with intravenous vancomycin for infection control. Following 2 sessions of VSD therapy, the infection was effectively controlled, with good granulation tissue formation, significant reduction in joint swelling, and negative bacterial culture results. At the 6-month follow-up, the elbow remained stable without signs of recurrent infection; the patient reported mild pain and limited range of motion, and definitive reconstructive surgery was deferred due to ongoing risk of infection and patient preference. CONCLUSIONS This case suggests that early and thorough debridement combined with VSD is an effective local treatment strategy for CN patients with infection. This approach aids in infection control and promotes wound healing, thereby creating favorable conditions for subsequent functional recovery. VSD, through continuous negative pressure drainage and irrigation, effectively removes necrotic tissue and exudate, improves local microcirculation, and demonstrates good application value in managing CN-related infections.

Spinal Charcot arthropathy (SCA) is a rare, progressive, and destructive neurogenic joint disorder that develops in the setting of impaired sensory and autonomic innervation. Although once associated primarily with tabes dorsalis, spinal cord injury (SCI) is now the leading cause. The condition arises through a combination of autonomic dysregulation, bone resorption, and loss of proprioceptive feedback, resulting in progressive joint destruction and spinal instability. Diagnosis is often delayed, as symptoms such as deformity, instability, or autonomic dysreflexia (AD) may develop insidiously over the years. We report the case of a 28-year-old female patient with paraplegia secondary to a chronic T5 SCI who presented with progressive thoracic deformity due to a severe Charcot joint at T12, associated with fracture-dislocation and a large pseudomeningocele. Despite complete thecal sac transection, her neurological function remained stable. Surgical management involved T5-pelvis posterior fusion with vertebrectomy, expandable cage placement, and a four-rod construct for maximal biomechanical stability. Intraoperative neuromonitoring was utilized throughout the procedure. The thecal sac was ligated to control cerebrospinal fluid (CSF) leakage. Postoperatively, the patient experienced transient hypotension consistent with autonomic dysfunction, but otherwise recovered well, achieving stable spinal alignment and resolution of her spinal deformity at three-month follow-up. This case highlights several critical considerations in managing SCA, including the need for long-segment fixation extending to the pelvis to reduce recurrence, the advantages of multirod constructs for enhanced mechanical durability, and the importance of addressing CSF leaks from thecal sac injury. AD and hemodynamic instability must also be anticipated in this patient population. SCA should be suspected in paraplegic patients presenting with new deformity or instability, even at a young age. Early recognition and individualized surgical planning, including long-segment fusion, anterior column support, and definitive dural management, are essential to achieve durable stabilization and prevent recurrence. This case also highlights the importance of considering SCA among the differential diagnoses for progressive deformity in chronically paraplegic patients, while also recognizing alternative etiologies such as prior destabilizing surgery. This case contributes to the limited literature on SCA in young patients and offers practical insights for complex spinal reconstruction in neurologically impaired patients.

Tabetic arthropathy is a destructive neurogenic joint disorder occurring as a late manifestation of tertiary syphilis. Although it has become exceedingly rare owing to early and appropriate treatment of syphilis, it remains relevant in developing countries and poses significant management challenges. We report three cases of tabetic arthropathy diagnosed in our department. A retrospective analysis was conducted on three cases of tabetic arthropathy diagnosed in our department between January 2022 and December 2025. Our series included three patients (n=3) with a mean age of 66 years and a male predominance (sex ratio M/F: 2/1). The main presenting complaint was chronic, painless, bilateral involvement of the knees, with a mean duration of seven months, without constitutional symptoms. The diagnosis of tabetic arthropathy was established based on painless bilateral arthropathy of the knees, characteristic radiological features combining destructive and hypertrophic osteoarticular lesions with intra-articular osteocartilaginous fragments and positive serologic tests in serum (3/3 patients), synovial fluid (3/3 patients), and cerebrospinal fluid (3/3 patients). Cardiovascular and neurological manifestations of tertiary syphilis were identified in one patient, consisting of aortic regurgitation and syphilitic cerebral arteritis. Treatment consisted of parenteral ceftriaxone due to the unavailability of penicillin G, the reference therapy. Tabetic arthropathy is a rare complication of neurosyphilis that remains relevant today in developing countries. The diagnosis should be considered in the presence of any destructive and painless joint disease. Given the difficulty in managing this articular form, prevention through early-stage treatment of syphilis is essential.

Neuropathic arthropathy (NA) is a chronic, progressive, destructive, aseptic inflammatory joint disorder resulting from sensory neurological deficit. We report a new case of NA with simultaneous involvement of the shoulder, elbow, and hands secondary to syringomyelia. Due to the rarity of this condition and its unusual location. The patient presented with painless deformation of both hands. Clinical examination revealed amyotrophy in both hands associated with hypoesthesia and bilateral areflexia of the upper limbs. The plain radiographs showed bone destruction and reconstruction in the metacarpophalangeal and interphalangeal joints, as well as obvious intra- and extra-articular bone debris in the elbows and the shoulders. Magnetic resonance imaging of the spinal cord revealed extensive syringomyelia in the cervical-thoracic region. This case demonstrates the role of imaging in the diagnosis of NA caused by syringomyelia; it is rare and poorly documented in the literature. Arthropathy of the hands is therefore extremely rare. This atypical condition should be considered particularly when it affects the upper limbs.

Active Charcot neuroarthropathy (CN) remains difficult to predict. This hypothesis-generating article proposes a deliberately restricted, testable model in which a clinically meaningful fall in HbA1c may temporally coincide with active CN in a subset of people with diabetes, established neuropathy, and a vulnerable foot. The signal is based on a sequence of observations-an initial case report, a 44-case retrospective series, and the EPiChar study-and therefore is supportive of association and biological plausibility, but not causation. Within this framework, osteocalcin should presently be regarded mainly as a candidate biomarker of a transient skeletal activation state rather than a proven pathogenic mediator. This article should therefore be read as a suggestion for prospective testing and not as confirmation of an osteocalcin-mediated pathway. We propose that this systemic signal may intersect with established local drivers-neuropathy, repetitive microtrauma, inflammation, and RANKL/OPG imbalance-and can be tested prospectively with serial bone turnover markers, neuropathy phenotyping, kidney function, and modifiable exposure data during treatment intensification.

Ankle and hindfoot Charcot neuroarthropathy is a complex problem and should be carefully assessed and managed to prevent morbidity and limb loss. Circular frames offer a range of options to address a wide variety of clinical situations and also complement internal fixation techniques. Multidisciplinary care and specialist skills to provide frame treatment are essential for a successful outcome.

The midfoot is the most frequent location of foot involvement in Charcot neuroarthropathy (CNA), and there is heterogeneity in clinical presentations depending on the joints involved and degree of bone destruction The present review encompasses the current indications and an algorithm for the management of minimally invasive correction of CNA midfoot deformities in both active and inactive settings using multiplanar circular external fixation. The latter is part of a 2-step procedure, including arthrodesis with intramedullary beaming, to maintain the achieved 3-dimensional correction.

Juvenile idiopathic arthritis (JIA) represents the most common cause of chronic arthritis in childhood; however, not all early-onset arthropathies are inflammatory in origin. We report the case of a 4-year-old girl initially diagnosed with oligoarticular JIA and treated with methotrexate followed by a tumor necrosis factor inhibitor, without significant clinical improvement and despite persistently normal inflammatory markers. Clinical reassessment raised suspicion of a non-inflammatory arthropathy, supported by characteristic radiographic findings including metaphyseal flaring of the distal femora and proximal tibiae. Genetic analysis identified compound heterozygous pathogenic variants in the PRG4 gene, confirming the diagnosis of camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome (OMIM #208250). PRG4 encodes lubricin, a mucin-like glycoprotein essential for boundary lubrication of articular cartilage and maintenance of synovial joint homeostasis. Loss-of-function variants disrupt joint lubrication, leading to mechanical synovial hyperplasia and chronic non-inflammatory joint effusion. This case highlights common diagnostic pitfalls in pediatric rheumatology and underscores the importance of considering genetic causes of chronic arthropathy when clinical and laboratory features are atypical for inflammatory disease. Early molecular diagnosis prevents unnecessary immunosuppressive therapy and enables appropriate multidisciplinary management.

Tabetic arthropathy is a destructive neurogenic joint disease that has become rare due to the early treatment of syphilis with penicillin G. It results from neurosyphilis caused by Treponema pallidum. The diagnosis is suspected in patients presenting with severe joint destruction disproportionate to the absence or minimal intensity of pain and is confirmed by positive syphilitic serological tests. We report the case of a 62-year-old patient with a history of high-risk sexual behavior and a remote episode of cervical lymphadenopathy treated 40 years ago. He presented with chronic painless monoarthritis of the right knee, without fever, associated with elevated inflammatory markers. Knee radiography revealed destruction of the medial tibial condyle, while magnetic resonance imaging (MRI) demonstrated osteolytic lesions of the medial tibial plateau with bone fragment detachment. The diagnosis of tabetic arthropathy was confirmed by positive syphilis serology. The clinical course was favorable following appropriate treatment, with marked clinical and biological improvement. Although exceptional, tabetic arthropathy should be considered in cases of painless destructive arthropathy. Treatment is primarily based on intravenous penicillin G, with third-generation cephalosporins as an alternative when penicillin is unavailable.

Charcot neuroarthropathy and diabetic bone disease share a unifying pathophysiology characterized by inflammatory osteolysis, vascular rarefaction, neurotrophic failure, and progenitor exhaustion. Once viewed as a localized mechanical process in an insensate foot, Charcot is now understood as a systemic marrow niche collapse driven by chronic inflammation and metabolic stress. This article outlines the molecular, cellular, and structural mechanisms underlying this process and explores emerging diagnostic and therapeutic approaches designed to restore osteoimmunologic balance and bone integrity in the diabetic host.