Herman M Kroon

Leiden University Medical Center

Psammomatoid ossifying fibroma (PsOF), also known as juvenile PsOF, is a benign fibro-osseous neoplasm predominantly affecting the extragnathic bones, particularly the frontal and ethmoid bones, with a preference for adolescents and young adults. The clinical and morphologic features of PsOF may overlap with those of other fibro-osseous lesions, an...

Purpose Acromegalic arthropathy is a well-known phenomenon, occurring in most patients regardless of disease status. To date, solely hips, knees, hands, and spinal joints have been radiographically assessed. Therefore, this study aimed to assess the prevalence of joint symptoms and radiographic osteoarthritis (OA) of new, and established peripheral...

Purpose Pain is a common symptom of acromegaly, impairing health-related quality of life (HR-QoL) significantly despite long-term disease remission. Neuropathic-like pain (NP-like) symptoms are invalidating, with great impact on HR-QoL. Studies characterizing or investigating the etiology of pain in acromegaly are scarce. Therefore, we aimed to ass...

Purpose Acromegalic arthropathy is a well-known phenomenon, occurring in most patients regardless of disease status. To date, solely hips, knees, hands, and spinal joints have been radiographically assessed. Therefore, this study aimed to assess the prevalence of joint symptoms and radiographic osteoarthritis (OA) of new, and established peripheral...

Purpose Bone health is compromised in acromegaly resulting in vertebral fractures (VFs), regardless of biochemical remission. Sclerostin is a negative inhibitor of bone formation and is associated with increased fracture risk in the general population. Therefore, we compared sclerostin concentrations between well-controlled acromegaly patients and...

Background: With soft-tissue sarcoma of the extremity (ESTS) representing a heterogenous group of tumors, management decisions are often made in multidisciplinary team (MDT) meetings. To optimize outcome, nomograms are more commonly used to guide individualized treatment decision making. Purpose: To evaluate the influence of Personalised Sarcoma...

A simple bone cyst (SBC) is a cystic bone lesion predominantly affecting young males. The cyst is lined by a fibrous membrane and filled with serosanguinous fluid. EWSR1/FUS-NFATC2 rearrangements were recently identified in SBC. We here report exactly the same rearrangement in 3 lesions diagnosed as vascular malformations of 2 elderly patients. In...

Cementoblastomas are rare odontogenic tumors developing in close proximity to the roots of teeth. Due to their striking morphologic resemblance to osteoblastomas of the peripheral skeleton, we set out to determine whether cementoblastomas harbor the same FOS rearrangements with overexpression of c-FOS as has recently been described for osteoblastom...

Background We aimed to investigate the application of the Knee Injury and Osteoarthritis Outcome Score (KOOS) percentile curves, using pre- and postoperative data of patients with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). Methods We used Longitudinal Leiden Orthopaedics Outcomes of Osteo-Arthritis study (LOAS) data of pati...

Introduction Pathologically high growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels in patients with acromegaly are associated with arthropathy. Several studies highlight the potential role of the GH/IGF-1 axis in primary osteoarthritis (OA). We aimed to disentangle the role of IGF-1 levels in primary OA pathogenesis. Methods Pati...

Context Joint complaints in patients with acromegaly are common, although the long-term disease course is largely unknown. Objective To evaluate the long-term course of acromegalic arthropathy. Design and setting Prospective longitudinal cohort study of controlled acromegaly patients followed at a tertial referral center, with three study visits:...

Objective Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) excess results in both reversible and irreversible musculoskeletal damage, including increased vertebral fracture (VF) risk. The prevalence of VFs is approximately 60% in controlled acromegaly patients, and these VFs can progress in time. We aimed to identify the course of VFs i...

Objective To investigate the two‐year course of pain and osteoarthritic magnetic resonance imaging (MRI) features in the thumb base. Methods Patients of the Hand OSTeoArthritis in Secondary care (HOSTAS) cohort who underwent hand radiography, MRI and clinical examination of the right thumb base at baseline and two‐year follow‐up were studied. Pain...

Osteoid osteoma and osteoblastoma are bone-forming tumors shown to harbor FOS (87%) and FOSB (3%) rearrangements. The aim was to evaluate the immunohistochemical expression of FOS and FOSB in these tumors in comparison to other bone tumors, to evaluate the influence of decalcification, and to correlate immunohistochemical findings with the underlyi...

According to the WHO, mesenchymal tumours of the maxillofacial bones are subdivided in benign and malignant maxillofacial bone and cartilage tumours, fibro-osseous and osteochondromatous lesions as well as giant cell lesions and bone cysts. The histology always needs to be evaluated considering also the clinical and radiological context which remai...

Background and purpose: Patients with advanced cancer may develop painful bone metastases, potentially resulting in pathological fractures. Adequate fracture risk assessment is of key importance to prevent fracturing and maintain mobility. This study aims to validate the clinical reliability of axial cortical involvement with a 30 mm threshold on...

Context The X-linked immunoglobulin superfamily, member 1 (IGSF1) gene is highly expressed in the hypothalamus and in pituitary cells of the POU1F1 lineage. Human loss-of-function mutations in IGSF1 cause central hypothyroidism, hypoprolactinemia, and macroorchidism. Additionally, most affected adults exhibit higher than average IGF-1 levels and an...

Purpose: To determine whether patient-specific finite element (FE) computer models are better at assessing fracture risk for femoral bone metastases compared to clinical assessments based on axial cortical involvement on conventional radiographs, as described in current clinical guidelines. Methods: Forty-five patients with 50 femoral bone metas...

Rhabdomyosarcomas with TFCP2 fusions represent an emerging subtype of tumors, initially discovered by RNA-sequencing. We report herein the clinicopathological, transcriptional, and genomic features of a series of 14 cases. Cases were retrospectively and prospectively recruited and studied by immunohistochemistry (MYF4, MYOD1, S100, AE1/E3, ALK), fl...

Radiomics can differentiate an enchondroma (a “don't touch” lesion) from an atypical cartilaginous tumor (which justifies watchful waiting) and a high‐grade chondrosarcoma (which necessitates resection with negative margins), and it will aid in individualized medicine for cartilaginous lesions of the appendicular skeleton.

Background: Hand osteoarthritis (OA) typically affects the interphalangeal (IP) joints and the thumb base (TB), including the first carpometacarpal (CMC-1) and scaphotrapeziotrapezoid (STT) joints. Based on previous studies, TB OA can be considered a distinct hand OA subset with a high burden of disease. In a cross-sectional study it was shown tha...

Editor's Note.- RadioGraphics continues to publish radiologic-pathologic case material selected from the "best case" presentations of the American Institute for Radiologic Pathology (AIRP), a program of the American College of Radiology. The AIRP conducts a 4-week Radiologic Pathology Correlation Course, which is offered five times per year. On the...

Background: Osteoarthritis (OA) severity as demonstrated by preoperative radiographs and preoperative pain play an important role in the indication for total knee arthroplasty (TKA). We investigated whether preoperative radiographic evidence of OA severity modified the effect of preoperative self-reported pain on postoperative pain and function 1...

Objective Aneurysmal bone cysts (ABC) rarely present in soft tissue locations (STABC). The 30 cases of STABC reported in the English literature were reviewed. Six new cases retrieved from the files of the Netherlands Committee on Bone Tumors were compared to the six cases described in the radiological literature. Materials and methods Imaging stud...

Objective: To investigate the construct validity of the new thumb base OA magnetic resonance imaging (MRI) scoring system (TOMS) by comparing TOMS scores with radiographic scores in patients with primary hand OA. Design: In 200 patients (83.5% women, mean (SD) age 61.0 (8.4) years), postero-anterior radiographs and MR scans (1.5 T) of the right...

Background Radiographic osteoarthritis (OA) severity and pain play an important role in the indication for total knee arthroplasty (TKA). It is however unkonw whether preoperative self-reported clinical pain modifies the effect of radiographic OA severity on postoperative pain and function in OA patients after TKA. Objectives To investigate whethe...

Information on the association of self‐reported knee instability with clinical outcomes after Total Knee Arthroplasty (TKA) and 1 year follow‐up is scarce. The aims were to determine (i) the course and prevalence of self‐reported knee instability before and 1 year after TKA and (ii) the associations of preoperative, postoperative, and retained self...

Introduction: Vertebral fractures are traditionally diagnosed using conventional radiographs of the spine. Vertebral fracture assessment (VFA) has been advocated as an alternative tool in the diagnosis of these fractures. Methods: We conducted a retrospective study as well as a systematic review and a meta-analysis to evaluate the performance of...

BACKGROUND: Osteomyelitis is usually caused by an infection. A non-infectious cause should be considered if antibiotic treatment is insufficiently effective and disease is recurrent, multifocal or migrating. CASE DESCRIPTION: A 14-year-old girl, an active volleyball player, developed episodes of fever and pain in her right lower leg. MRI showed ost...

In clinical practice, conventional radiograph is still the radiologic method for the diagnosis of rheumatoid arthritis (RA). Moreover, it provides a quick overview of the symptomatic joints, to narrow the differential diagnosis, and to evaluate progression. RA is a polyarticular disease with bilateral and symmetric involvement of the peripheral joi...

Background: Childhood obesity is associated with advanced bone age (BA). Previous studies suggest that androgens, oestrogens, sex hormone-binding globulin, and insulin are responsible for this phenomenon, but results are contradictory and might be biased by confounders. We aim to elucidate this matter by applying a multivariate approach. Method:...

Background: Arthropathy is a prevalent and invalidating complication of acromegaly with a characteristic radiographic phenotype. We aimed to further characterize cartilage and bone abnormalities associated with acromegalic arthropathy using magnetic resonance imaging (MRI). Methods: Twenty-six patients (23% women, mean age 56.8 ± 13.4 years), wi...

Objective: Acromegaly is a rare disease caused by excess growth hormone (GH) production by a pituitary adenoma. The skeletal complications of GH and IGF-1 excess include increased bone turnover, increased cortical bone mass and deteriorated microarchitecture of trabecular bone, associated with a high risk of vertebral fractures in the presence of...

Background: Osteomyelitis is usually caused by an infection. A non-infectious cause should be considered if antibiotic treatment is insufficiently effective and disease is recurrent, multifocal or migrating. Case description: A 14-year-old girl, an active volleyball player, developed episodes of fever and pain in her right lower leg. MRI showed...

Fibrous dysplasia is a rare genetic bone disorder with a wide variation in clinical expression, ranging from asymptomatic patients to severely affected patients with extensive bone disease, pain, repetitive fractures and deformities and serious endocrinological symptoms (McCune-Albright syndrome). Here, we report on three different cases of fibrous...

Objective: To investigate the course of synovitis on contrast-enhanced MRI in osteoarthritic knees over 2 years, and its association with pain and cartilage deterioration. Design: Consecutive patients (n=39, mean age 61 years, 79% woman, median (range) BMI 29 (24-48) kg/mm(2)) with clinical OA were included. Baseline and follow-up contrast-enhan...

Background Self-reported knee instability has been reported in 60–80% of all patients suffering from mild to moderate knee osteoarthritis (OA) [1], but the prevalence of self-reported knee joint instability in patients with end-stage OA is unknown. So far, a clear cause for this sense of instability has not been elucidated. Two opposing hypotheses...

Objective: To get a better understanding of inflammatory pathways active in the osteoarthritic (OA) joint, we characterized and compared inflammatory cells in the synovium and the infrapatellar fat pad (IFP) of patients with knee OA. Methods: Infiltrating immune cells were characterized by flow cytometry in 76 patients with knee OA (mean age 63....

Purpose: Clinicians do not currently have a simple means of identifying patients at risk for developing incident and persisting knee symptoms in osteoarthritis (OA). We examined whether a clinically detected knee effusion predicts this. Methods: Data were extracted from the Osteoarthritis Initiative. All participants (n ¼ 4646) and the subgroup wit...

Primary bone tumors of the spine are less common than metastases or multiple myeloma. Based on the patient's age and the radiologic pattern and topography of the tumor, a very approximate differential diagnosis can be established for an osseous vertebral lesion. This article shows the radiologic manifestations of the principal primary bone tumors o...

Objective: To investigate the presence of mast cells in the osteoarthritic (OA) synovium and their association with clinical parameters in comparison with rheumatoid arthritis (RA) samples. Method: Synovial tissues of 56 symptomatic OA and 49 RA patients were obtained. Two to three paraffin slides were used to quantify inflammation using haemato...

Background: Chondrosarcoma of the rib is a rare disease. Although surgery is the only curative treatment option, rib resection with an adequate margin can be challenging and local recurrence is a frequent problem. In this study, the prognosis of primary and recurrent chondrosarcoma of the rib is reported. Methods: Retrospective analysis was perf...

Background and purpose There is no consensus on the impact of radiographic severity of hip and knee osteoarthritis (OA) on the clinical outcome of total hip arthroplasty (THA) and total knee arthroplasty (TKA). We assessed whether preoperative radiographic severity of OA is related to improvements in functioning, pain, and health-related quality of...

Objective: To investigate patterns of MRI abnormalities in the patellofemoral (PFJ) and tibiofemoral joint (TFJ) and their association with radiographic progression, using hypothesis free analyses. Design: 205 patients from the GARP study with symptomatic OA at multiple sites (mean age 60 years, 80% woman, median BMI 26 kg/m(2)), underwent knee...

The aim of this study was to measure return to work and duration until return to work in patients undergoing total hip or knee arthroplasty (THA or TKA). This prospective study included patients under 65 years of age, undergoing THA or TKA, who provided information on their work status preoperatively (paid work yes/no and working hours) and 1 year...

Introduction: Osteoporosis and fractures are common in liver disease and fracture incidence increases after orthotopic liver transplantation (OLT). The value of bone turnover markers (BMTs) in the prediction of bone loss and fracture risk pre- and post-OLT is not known. Study design: The BMTs P1NP, osteocalcin, BALP and CTX were measured initially...

Periosteal chondrosarcoma is a rare, malignant cartilage-forming neoplasm originating from the periosteal surface of bone. We collected 38 cases from the archives of the Netherlands Committee on Bone Tumors and studied histological features and evaluated the involvement of IDH, EXT, Wnt/β-catenin, pRB- (CDK4 and p16), and TP53-pathway (p53 and MDM2...

Functional imaging, in particular dynamic contrast-enhanced MRI (DCE-MRI), has a role in differentiating benign from malignant cartilaginous tumors. Chondrosarcoma grade I or atypical cartilaginous tumor enhances within 10 s. of arterial enhancement. Enchondroma enhances after 10 s. or not at all. FDG-PET has the same uptake patterns in both enchon...

Objective: To determine patterns of synovitis on contrast-enhanced magnetic resonance images and its relation to pain and severity of radiographic OA. Methods: 86 patients (mean age 62 years, 66% woman, median BMI 29 kg/mm(2) and Kellgren-Lawrence score 3 ) with symptomatic knee OA were included. T1-weighted Gd-chelate-enhanced MRI with fat-suppres...

Objectives: To investigate whether all-cause mortality and deaths due to cardiovascular disease are increased in patients who have consulted primary or secondary health care with symptoms and signs of osteoarthritis (OA). Method: This study included 383 patients with symptomatic OA at multiple sites from the Genetics ARthrosis and Progression (G...

Purpose: Syndromes with focal overgrowth are rare and diagnosis is difficult because manifestations are highly variable and symptoms overlap between syndromes. Diagnosis depends on clinical history, physical examination, and radiologic and histologic findings. This report describes a case of focal overgrowth of the left seventh rib and half of the...

Osteoporosis is prevalent in end-stage liver disease, but data on long-term changes in bone mineral density (BMD) and related fracture incidence are scarce after orthotopic liver transplantation (OLT). We evaluated BMD changes up to 5 years in consecutive recipients of a successful OLT at the Leiden University Medical Centre between 2000 and 2011,...

Context: Osteoporosis and fractures are prevalent after orthotopic liver transplantation (OLT), but data on these skeletal complications are scarce in patients with end-stage liver disease awaiting liver transplantation. Objective: To evaluate the prevalence of vertebral fractures (VFs) in OLT recipients at the time of screening for transplantat...

Background Mast cells could be important in osteoarthritis (OA), as it is the only type of immune cell whose numbers were shown to be as high or sometimes higher compared to rheumatoid arthritis (RA). To assess their role in OA, we investigated whether the number and activation status of mast cells varies with the disease stage in OA. Objectives To...

In this case study, we describe the clinical presentation and treatment of 36 patients with periosteal chondrosarcoma collected over a 59-year period by the archive of the Netherlands Committee on Bone Tumours. The demographics, clinical presentation, radiological features, treatment and follow-up are presented with the size, location, the histolog...