Diagnostic value of open incisional biopsies in suspected, difficult-to-diagnose periprosthetic hip joint infection prior to revision surgery.

INTRODUCTION: Prior to revision of total hip arthroplasty (THA), low-grade chronic periprosthetic joint infection (PJI) is often difficult to diagnose. We aimed to determine the diagnostic accuracy of open incisional tissue biopsy for the prediction of PJI prior to THA revision in cases with culture-negative or dry tap joint aspirates. MATERIALS AND METHODS: This retrospective single-center study includes 32 consecutive THA revision cases with high clinical suspicion of low-grade chronic PJI of the hip with culture-negative or dry tap joint aspirates and without systemic signs of infection. Open incisional biopsy (OIB) was performed prior to revision surgery. Periprosthetic tissue samples were analyzed by microbiology and histopathology for PJI. During definitive revision arthroplasty, identical diagnostics were repeated. Results from both procedures were compared and sensitivity, specificity, positive and negative predictive values of OIB for the final diagnosis were calculated. RESULTS: Average age at revision was 69.3 ± 13.5 years. The sensitivity of the OIB procedure was 80% (microbiology), 69% (histology) and 82% for combined analyses (microbiology and histology). Specificity of OIB was 80% (microbiology), 94% (histology) and 60% for combined analyses. CONCLUSIONS: Open tissue biopsy performed in cases with culture-negative or inconclusive synovial fluid aspirates prior to revision of THA has limited diagnostic accuracy for the prediction of PJI. The procedure does not reliably close the diagnostic gap in a substantial number of cases. In this difficult patient population, risk of an open procedure may outweigh benefits and alternative less invasive methods should be considered for the preoperative diagnosis of PJI.

Diagnostic accuracy of alpha-defensin enzyme-linked immunosorbent assay in the clinical evaluation of painful hip and knee arthroplasty with possible prosthetic joint infection: a prospective study of 202 cases.

AIMS: The aim of this study was to evaluate the diagnostic accuracy of the synovial alpha-defensin enzyme-linked immunosorbent assay (ELISA) for the diagnosis of prosthetic joint infection (PJI) in the work-up prior to revision of total hip (THA) and knee arthroplasty (TKA). PATIENTS AND METHODS: Inclusion criteria for this prospective cohort study were acute or chronic symptoms of the index joint without specific exclusion criteria. Synovial fluid aspirates of 202 patients were analyzed and semiquantitative laboratory alpha-defensin ELISA was performed. Final diagnosis of PJI was established by examination of samples obtained during revision surgery. RESULTS: Sensitivity and specificity of the alpha-defensin ELISA for PJI were 78.2% (95% confidence interval (CI) 66.7 to 88.5) and 96.6% (95% CI 93.0 to 99.3). Positive and negative predictive values were 89.6% (95% CI 80.6 to 97.8) and 92.2% (95% CI 87.5 to 96.1). The test remained false-negative in 22% of septic revisions, most of which were due to coagulase-negative staphylococci all occurring in either late-chronic or early-postoperative PJI. CONCLUSION: The routine use of synovial fluid alpha-defensin laboratory ELISA in the preoperative evaluation of symptomatic THAs and TKAs is insufficient to accurately diagnose PJI. Particularly in cases involving low-virulence organisms, such as coagulase-negative staphylococci, there remains a need for tests with a higher sensitivity. Cite this article: Bone Joint J 2019;101-B:970-977.

MRI and sonography in Legg-Calvé-Perthes disease: clinical relevance of containment and influence on treatment.

PURPOSE: The containment orientated treatment of Legg-Calvé-Perthes disease (LCPD) affected hip joints is broadly accepted in the literature. The prerequisite is early recognition of loss of containment. An often-used quantitative MRI containment parameter is the cartilaginous acetabulum-head-index (CAHI). Based on ultrasound (US), we analyzed the newly created 'femoral head extrusion angle' (HA) as a containment parameter in comparison with the CAHI in severe LCPD. METHODS: In a prospective study with 40 children (mean age 5.8 years sd 2.3) with unilateral LCPD classified as Catterall group III/IV, we measured the CAHI versus HA to assess the containment of the femoral head. HA in US was determined by the tangent from the bony acetabular rim to the cartilaginous cranio-lateral femoral head. RESULTS: The HA was significantly higher in LCPD-affected hip joints (25° sd 7°) than in healthy ones (13° sd 5°; p < 0.001). Correlation analysis of all hip joints revealed a significant correlation between HA and CAHI (r = -0.69; p < 0.001). Hip joints with a low CAHI indicating loss of containment showed a higher HA in sonography. CONCLUSION: The results of our study suggest that the HA in US is a reliable containment parameter in severe LCPD with a HA > 22° defining a pathologic value. In comparison with the CAHI, HA measurement in ultrasound is easier than the assessment of various parameters to calculate an index. Frequent sonographical follow-up assessment in critical joints is an alternative if MRI is not available, helping to detect an impending loss of containment early enough. LEVEL OF EVIDENCE: Level II.

Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue.

BACKGROUND: The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination. METHODS: The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles. RESULTS: All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis. CONCLUSIONS: The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

[Prevalence, comorbidity and interdisciplinary treatment of rheumatoid arthritis - Insurance data on outpatient and inpatient care in Baden-Württemberg]. / Prävalenz, Komorbidität und interdisziplinäre Versorgung der Rheumatoiden Arthritis ­ Versicherungsdaten zur ambulanten und stationären Versorgung in Baden-Württemberg.

BACKGROUND: Rheumatoid arthritis (RA) has an increased number of comorbidities compared with the general population. OBJECTIVE: Study aim was to collect epidemiological data on prevalence, incidence and comorbidities of RA as well as utilization of outpatient and inpatient care services. MATERIAL AND METHODS: In an age and gender-adjusted case control study, a total of 3.4 million patients insured by the AOK Baden-Württemberg were analysed with respect to visits to physicians, prevalence, incidence and comorbidities of RA. The study was based on out- and inpatient diagnoses from 2013. RESULTS: The RA prevalence was 0.64% (n = 26,919), the incidence was 0.04%. Patients with RA have significant more comorbidities in almost all diagnosis groups, especially in musculoskeletal and cardiovascular diseases, compared to a control group (n = 181,209). 22.8% of RA patients had not contacted an internist rheumatologist, orthopedist or orthopedic surgeon. Biological disease-modifying anti-rheumatic drugs (DMARDs) were almost exclusively prescribed by internist rheumatologists, while conventional DMARDs were equally prescribed by general practitioners and rheumatologists. Of the RA patients 32.6% were hospitalized at least once a year and were nearly twice as frequently inpatient as the control group. CONCLUSION: RA patients need more in- and outpatient healthcare services and suffer significantly more often from comorbidities. The general practitioner is the most frequently visited physician. Other consulted physicians are rheumatologists, ophthalmologists, orthopedists/orthopedic surgeons and internists not specialized in rheumatology. The study highlights the need to create consensus treatment algorithms and maintain a close interdisciplinary and intersectoral cooperation and communication.

[The rheumatic cervical spine]. / Die rheumatische Halswirbelsäule.

BACKGROUND: The cervical spine is one of the main sites of manifestation in rheumatoid arthritis outside of the extremities. It can have a decisive influence on disease course via the occurrence of mechanical instabilities as well as neurologic symptoms. Both adequate diagnosis and the corresponding surgical treatment represent a challenge for the involved physicians. MATERIALS AND METHODS: This review presents relevant diagnostic strategies and possibilities for surgical intervention which aim to avoid potentially fatal neurologic symptoms. Basic literature and expert opinions are also discussed. RESULTS AND CONCLUSION: Through target-oriented surgical management, as well as tight clinical and radiologic monitoring during conservative and surgical therapy, potentially fatal disease courses can be avoided.

15 years of the histopathological synovitis score, further development and review: A diagnostic score for rheumatology and orthopaedics.

The histopathological synovitis score evaluates the immunological and inflammatory changes of synovitis in a graduated manner generally customary for diagnostic histopathological scores. The score results from semiquantitative evaluation of the width of the synovial surface cell layer, the cell density of the stroma and the density of the inflammatory infiltration into 4 semiquantitative levels (normal 0, mild 1, moderate 2, severe 3). The addition of these values results in a final score of 0-9 out of 9. On the basis of this summation the condition is divided into low-grade synovitis and high-grade synovitis: A synovitis score of 1 to≤4 is called low-grade synovitis (arthrosis-associated/OA synovitis, posttraumatic synovitis, meniscopathy-associated synovitis and synovitis with haemochromatosis). A synovitis score of≥5 to 9 is called high-grade synovitis (rheumatoid arthritis, psoriatic arthritis, Lyme arthritis, postinfection/reactive arthritis and peripheral arthritis with Bechterew's disease). By means of the synovitis score it is therefore possible to distinguish between degenerative/posttraumatic diseases (low-grade synovitis) and inflammatory rheumatic diseases (high-grade synovitis) with a sensitivity of 61.7% and a specificity of 96.1%. The diagnostic accuracy according to ROC analysis (AUC: 0.8-0.9) is good. Since the first publication (2002) and an associated subsequent publication (2006), the synovitis score has nationally and internationally been accepted for histopathological assessment of the synovitis. In a PubMed data analysis (status: 14.02.2017), the following citation rates according to Cited by PubMed Central articles resulted for the two synovitis score publications: For DOI: 10.1078/0344-0338-5710261 there were 29 Cited by PubMed Central articles and for the second extended publication DOI:10.1111/j.1365-2559.2006.02508 there were 44 Cited by PubMed Central articles. Therefore a total of 73 PubMed citations are observed over a period of 15 years, which demonstrates an international acceptance of the score. This synovitis score provides for the first time a diagnostic, standardised and reproducible histopathological evaluation method enabling a contribution to the differential diagnosis of chronic inflammatory general joint diseases. This is particularly the case by incorporation into the joint pathology algorithm. To specify the synovitis score an immunohistochemical determination of various inflammation-relevant CD antigens is proposed to enable a risk stratification of high-grade synovitis (e.g.: progression risk and sensitivity for biologicals).

[Fifteen years of the histopathological synovitis score : Review and further developments of a diagnostic score]. / 15 Jahre histopathologischer Synovialitis-Score : Rückblick und Weiterentwicklung eines diagnostischen Scores.

The histopathological synovitis score evaluates in a graded approach, as is largely usual for diagnostic histopathological scores, the immunological and inflammatory changes caused by synovitis. A synovitis score of between 1 and ≤ 4 is classified as low-grade (osteoarthritis-related synovitis, post-traumatic synovitis, meniscopathy-related synovitis and synovitis in hemochromatosis). Synovitis scores of between ≥ 5 and 9 are classified as high-grade synovitis (rheumatoid arthritis, psoriatic arthritis, Lyme's arthritis, post-infection/reactive arthritis and peripheral arthritis in Bechterew disease); sensitivity is 61.7% and sensitivity 96.1%. According to receiver operating characteristic (ROC) analysis (AUC: 0.8-0.9), diagnostic value is good. National and international acceptance of the synovitis score has grown since the first publication in 2002 and a related follow-up publication in 2006. PubMed data analysis (as of 11.01.2017) yielded the following citation values according to "cited by PubMed Central articles" for two publications relating to the synovitis score: there were 29 cited-by-PubMed articles for DOI: 10.1078/0344-0338-5710261 , and 44 cited-in-PubMed articles for the second publication, DOI: 10.1111/j.1365-2559.2006.02508 . This makes a total of 73 PubMed citations over a period of 15 years, thereby evidencing the score's international acceptance. Immunohistochemical determination of a number of CD antigens relevant to inflammation has been proposed to further specify the synovitis score for the purposes of risk stratification of high-grade synovitis (e.g., risk of progression and sensitivity to biological agents).

Clinical, radiographic and biochemical characteristics of adult hypophosphatasia.

In this study, we report on clinical, radiographic and biochemical characteristics of 38 patients with adult hypophosphatasia. High-resolution peripheral quantitative computed tomography showed alterations of bone microstructure in a subgroup of 14 patients. Pyridoxal-5-phosphate levels correlated with the occurrence of fractures and the number of symptoms. INTRODUCTION: Hypophosphatasia (HPP) is a rare disorder with a wide range of clinical manifestations. A reduced enzymatic activity of alkaline phosphatase (ALP) is the key marker of the disease, causing an accumulation of ALP substrates such as pyridoxal-5-phosphate (PLP). The purpose of this retrospective study was to further characterize adult onset HPP. METHODS: We assessed clinical, radiographic and laboratory characteristics of 38 adult patients with HPP. Diagnosis of HPP was established by the combination of low-serum ALP, raised PLP levels and typical symptoms and was genetically confirmed in 32 patients. Dual-energy X-ray absorptiometry (DXA) and laboratory data were available in most patients. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed in 14 patients. RESULTS: Clinical characteristics included a wide spectrum of symptoms. A history of fracture was present in 15 patients (39%). Twenty-one patients (55%) complained about recurring headaches, 23 patients (61%) had recurring muscle pain, 4 patients (11%) suffered from severe muscle weakness and 18 patients (47%) showed dental abnormalities. Z-scores assessed by DXA were only slightly reduced in most adult HPP patients. HR-pQCT of 14 patients showed microstructural changes of trabecular and cortical bone compared to reference values of healthy subjects. The occurrence of fractures and multiple symptoms (>2 typical HPP symptoms) were associated with significantly elevated levels of PLP. CONCLUSION: Adult HPP presents with a wide range of clinical symptoms and is not associated with low bone mass in general. PLP seems to be a good marker for disease severity in adult patients as its level is correlated with the occurrence of fractures and number of symptoms.

Articular cartilage calcification of the hip and knee is highly prevalent, independent of age but associated with histological osteoarthritis: evidence for a systemic disorder.

OBJECTIVES: Based on the concept of a systemic predisposition for articular cartilage calcification (CC), the aim of this study was to determine the prevalence and amount of bilateral CC of hip and knee joints in an unselected sample cohort by high-resolution digital contact radiography (DCR) and to analyze the association of CC with histological OA. METHODS: Both hip and knee joints of 87 donors (48 m and 39 f; mean age 62) were analyzed by DCR in this post-mortem study of an unselected cohort of donors. Histological OA (OARSI) of the main load bearing area of femoral heads and medial femoral condyles was determined. RESULTS: The prevalence of CC of the femoral head was 96.6%, of the knee 94.3%. Bilateral calcification was detected in 79.3% of hips and 86.2% of knees. Concomitant CC of all four joints was detected in 69.0% of donors. There was no difference between the amount of CC of hips and knees (P = 0.47). The amount of CC of any given hip or knee correlated with that of the contralateral hip (rs = 0.54, P < 0.001) or knee (rs = 0.50, P < 0.001). There was a correlation between the amount of CC and histological OA (hips rs = 0.48, P < 0.001, knees rs = 0.30, P = 0.004), but not between CC and age (hips rs = -0.09, P = 0.42; knees rs = 0.10, P = 0.34). CONCLUSIONS: These data support the concept that articular CC occurs as the result of a systemic disorder. CC appears to be an early element of hip and knee OA pathogenesis independent of age.

[Standards of care for people with rheumatoid arthritis in Europe : Translation and comments of the eumusc.net recommendations supported by EULAR performed by a national task force of the professional organisations DGRh and VRA supported by "Deutsche Rheumaliga"]. / Europäische Versorgungsstandards für Menschen mit rheumatoider Arthritis : Übersetzung und Kommentierung der von der EULAR unterstützten Vorschläge des eumusc.net durch eine Task Force von DGRh und VRA mit Unterstützung der Deutschen Rheuma-Liga.

In a joint initiative by the boards of the German Society for Rheumatology (DGRh) and the Association of Rheumatology Clinics (VRA) the European "standards of care" for rheumatoid arthritis, recently suggested by the European Musculoskeletal Conditions Surveillance and Information Network (eumusc.net) and supported by the European League Against Rheumatism (EULAR), were translated and annotated. The recommendations include aspects of the management of the disease, actual medical care, and access to information - this includes all types of support people with RA need, and, last but not least communication of the necessary knowledge. Furthermore, health care structures such as the availability of medical staff with relevant expertise are also important.

[Indications and contraindications for radiosynoviorthesis]. / Indikationen und Kontraindikationen zur Radiosynoviorthese.

BACKGROUND: Radiosynoviorthesis (RSO) provides a simple method for the treatment of patients with chronic synovitis and has only few side effects. OBJECTIVES: Evidence-based indications and contraindications for performing RSO based on the current literature are presented. MATERIAL AND METHODS: Published information on the indications and contraindications for performing RSO in chronic synovitis were analyzed and summarized. RESULTS: According to the guideline recommendations of the German Society of Rheumatology indications for RSO are given in patients with rheumatoid arthritis, seronegative spondyloarthropathy, crystal arthropathy, villonodular synovitis and hemophilia with recurrent joint bleeding. Osteoarthritis with documented reactive synovitis is also regarded as an indication in the guidelines of the nuclear medicine societies. The European League Against Rheumatism (EULAR) and the German Society of Rheumatology (DGRh) have given no recommendations for using RSO in osteoarthritis. Given the correct indications RSO shows high success rates. CONCLUSION: The effects of RSO with the named secondary side effects last on average for 5 years. Crucial for the success of RSO are the correct indications, the correct timing and combination with other therapeutic procedures, such as surgical synovectomy.

Revised histopathological consensus classification of joint implant related pathology.

This extended classification of joint implant related pathology is a practical histopathologic classification based on defined morphological criteria covering the complete spectrum of pathohistologic changes in periprosthetic tissues. These changes may occur as a consequence of endoprosthetic replacement of large joints and may lead to a reduction in the prosthesis survival rate. We describe the established consensus classification of the periprosthetic membrane, in which aseptic and septic prosthetic loosening can be subdivided into four histological types, as well as histopathological criteria for additional significant pathologies including endoprosthetic-associated arthrofibrosis, particle-induced immunological, inflammatory and toxic mechanisms (adverse reactions), and bone tissue pathologies. These characteristic tissue alterations and their relationships are summarized in the extended classification. Since particle heterogeneity in periprosthetic tissue is high and particle identification is a necessary part of diagnosis, the identification of different types of particles is described in the histopathological particle algorithm. The morphological qualities of prosthetic material particles and the demarcation between abrasion and non-abrasion endogenous particles are also summarized. This feasible classification which is based on low cost standard tissue processing and examination and on well-defined diagnostic criteria is a solid platform for the histological diagnosis of implant associated pathologies providing a stable and reproducible tool for the surgical pathologist. Since this classification is suitable for standardized histopathological diagnostics, it might also provide a useful data set for joint arthroplasty registers, particularly for registers based on so-called routine data.

[Histopathological particle algorithm. Particle identification in the synovia and the SLIM]. / Histopathologischer Partikelalgorithmus. Partikelidentifikation in der Synovialis und in der SLIM.

BACKGROUND: In the histopathological diagnostics of synovitis and the synovium-like interface membrane (SLIM) the identification of crystals and crystal-like deposits and the associated inflammatory reactions play an important role. The multitude of endogenous crystals, the range of implant materials and material combinations, and the variability in the formation process of different particles explain the high morphological particle heterogeneity which complicates the diagnostic identification of diagnostic particles. STUDY DESIGN AND METHODS: A simple histopathological particle algorithm has been designed which allows methodological particle identification based on (1) conventional transmitted light microscopy with a guide to particle size, shape and color, (2) optical polarization criteria and (3) enzyme histochemical properties (oil red staining and Prussian blue reaction). These methods, the importance for particle identification and the differential diagnostics from non-prosthetic materials are summarized in the so-called histopathological particle algorithm. RESULTS: A total of 35 cases of synovitis and SLIM were analyzed and validated according to these criteria. Based on these criteria and a dichotomous differentiation the complete spectrum of particles in the SLIM and synovia can be defined histopathologically. CONCLUSION: For histopathological diagnosis a particle score for synovitis and SLIM is recommended to evaluate (1) the predominant type of prothetic wear debris with differentiation between microparticles, and macroparticles, (2) the presence of non-prosthesis material particles and (3) the quantification of particle-association necrosis and lymphocytosis. An open, continuously updated web-based particle algorithm would be helpful to address the issue of particle heterogeneity and include all new particle materials generated in a rapidly changing field.

High fluoride and low calcium levels in drinking water is associated with low bone mass, reduced bone quality and fragility fractures in sheep.

UNLABELLED: Chronic environmental fluoride exposure under calcium stress causes fragility fractures due to osteoporosis and bone quality deterioration, at least in sheep. Proof of skeletal fluorosis, presenting without increased bone density, calls for a review of fracture incidence in areas with fluoridated groundwater, including an analysis of patients with low bone mass. INTRODUCTION: Understanding the skeletal effects of environmental fluoride exposure especially under calcium stress remains an unmet need of critical importance. Therefore, we studied the skeletal phenotype of sheep chronically exposed to highly fluoridated water in the Kalahari Desert, where livestock is known to present with fragility fractures. METHODS: Dorper ewes from two flocks in Namibia were studied. Chemical analyses of water, blood and urine were executed for both cohorts. Skeletal phenotyping comprised micro-computer tomography (µCT), histological, histomorphometric, biomechanical, quantitative backscattered electron imaging (qBEI) and energy-dispersive X-ray (EDX) analysis. Analysis was performed in direct comparison with undecalcified human iliac crest bone biopsies of patients with fluoride-induced osteopathy. RESULTS: The fluoride content of water, blood and urine was significantly elevated in the Kalahari group compared to the control. Surprisingly, a significant decrease in both cortical and trabecular bones was found in sheep chronically exposed to fluoride. Furthermore, osteoid parameters and the degree and heterogeneity of mineralization were increased. The latter findings are reminiscent of those found in osteoporotic patients with treatment-induced fluorosis. Mechanical testing revealed a significant decrease in the bending strength, concurrent with the clinical observation of fragility fractures in sheep within an area of environmental fluoride exposure. CONCLUSIONS: Our data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone mass and (ii) can cause fragility fractures and (iii) that the prevalence of skeletal fluorosis especially due to groundwater exposure should be reviewed in many areas of the world as low bone mass alone does not exclude fluorosis.

The influence of femoral offset on health-related quality of life after total hip replacement.

Several factors have been implicated in unsatisfactory results after total hip replacement (THR). We examined whether femoral offset, as measured on digitised post-operative radiographs, was associated with pain after THR. The routine post-operative radiographs of 362 patients (230 women and 132 men, mean age 70.0 years (35.2 to 90.5)) who received primary unilateral THRs of varying designs were measured after calibration. The femoral offset was calculated using the known dimensions of the implants to control for femoral rotation. Femoral offset was categorised into three groups: normal offset (within 5 mm of the height-adjusted femoral offset), low offset and high offset. We determined the associations to the absolute final score and the improvement in the mean Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain subscale scores at three, six, 12 and 24 months, adjusting for confounding variables. The amount of femoral offset was associated with the mean WOMAC pain subscale score at all points of follow-up, with the low-offset group reporting less WOMAC pain than the normal or high-offset groups (six months: 7.01 (sd 11.69) vs 12.26 (sd 15.10) vs 13.10 (sd 16.20), p = 0.006; 12 months: 6.55 (sd 11.09) vs 9.73 (sd 13.76) vs 13.46 (sd 18.39), p = 0.010; 24 months: 5.84 (sd 10.23) vs 9.60 (sd 14.43) vs 13.12 (sd 17.43), p = 0.004). When adjusting for confounding variables, including age and gender, the greatest improvement was seen in the low-offset group, with the normal-offset group demonstrating more improvement than the high-offset group.

[Dupuytren's contracture associated with silicone wear reaction in late failure of lunate bone spacer prosthesis]. / Silikonabriebassoziierte Dupuytren-Kontraktur bei Spätversagen einer Lunatumspacerprothese.

The pathophysiological mechanisms of palmar fibromatosis (Dupuytren's contracture) are still not yet fully understood. In the vast majority of cases, however, reactive changes and reparative processes of tendon tissue can easily be ruled out by clinical and histopathological investigations. This article presents the case of a 62-year-old male patient suffering from palmar fibromatosis associated with a failed silicon spacer of the lunate bone 30 years after index surgery. Although silicon wear particles were observed in distal locations, proximal tendon tissues showed changes consistent with a degenerative palmar fibromatosis in the absence of a pathological wear reaction. The findings are discussed in the light of the current literature on Dupuytren's contracture.