Aims. The management of periprosthetic joint infection (PJI) remains a major challenge in orthopaedic surgery. In this study, we aimed to characterize the local bone microstructure and metabolism in a clinical cohort of patients with chronic PJI. Methods. Periprosthetic femoral trabecular bone specimens were obtained from patients suffering from chronic PJI of the hip and knee (n = 20). Microbiological analysis was performed on preoperative joint aspirates and tissue specimens obtained during revision surgery. Microstructural and cellular bone parameters were analyzed in bone specimens by histomorphometry on undecalcified sections complemented by tartrate-resistant acid phosphatase immunohistochemistry. Data were compared with control specimens obtained during primary arthroplasty (n = 20) and aseptic revision (n = 20). Results. PJI specimens exhibited a higher bone volume, thickened trabeculae, and increased osteoid parameters compared to both control groups, suggesting an accelerated bone turnover with sclerotic microstructure. On the cellular level, osteoblast and osteoclast parameters were markedly increased in the PJI cohort. Furthermore, a positive association between serum (CRP) but not synovial (white blood cell (WBC) count) inflammatory markers and osteoclast indices could be detected. Comparison between different pathogens revealed increased osteoclastic bone resorption parameters without a concomitant increase in osteoblasts in bone specimens from patients with Staphylococcus aureus infection, compared to those with detection of Staphylococcus epidermidis and Cutibacterium spp. Conclusion. This study provides insights into the local bone metabolism in chronic PJI, demonstrating osteosclerosis with high bone turnover. The fact that Staphylococcus aureus was associated with distinctly increased osteoclast indices strongly suggests early surgical treatment to prevent periprosthetic bone alterations. Cite this article: Bone Joint Res 2023;12(10):644–653

Introduction. A staging system has been developed to revise the 1994 ARCO classification for ONFH. The final consensus resulted in the following 4-staged system: stage I—X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II—X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III—fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV—X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. Radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) scans may all be involved in diagnosing ONFH; however, the optimal diagnostic modality remains unclear. The purpose of this study was to identify: 1) how ONFH is diagnosed at a single academic medical center, and 2) if CT is a necessary modality for diagnosing/staging OFNH. Methods. The EMR was queried for the diagnosis of ONFH between 1/1/2008–12/31/2018 at a single academic medical center. CT and MRI scans were reviewed by the senior author and other contributors. The timing and staging quality of the diagnosis of ONFH were compared between MRI and CT to determine if CT was a necessary component of the ONFH work-up. Results. There were 803 patients with ONFH over the 10 years of study. 382 had CT only, 166 had MRI only, and 255 had both a CT and MRI. Of the 255 patients who had both CT and MRI, 228 actually had ONFH after inspection. A diagnosis of ONFH was made by MRI only in 57% (129/228) while another 21% (48/228) used MRI and CT simultaneously. 22% (51/228) of cases were diagnosed by CT scan first. 94% (48/51) of these cases involved a cancer (CA) diagnoses, the CT scans were used for CA staging and were not helpful with ARCO staging of ONFH. The other 3 cases identified asymptomatic ONFH. MRI scans performed after diagnosis with CT in symptomatic patients were then utilized for staging. Conclusion. Although CT scan was a useful adjunct for diagnosing ONFH during a staging workup for CA, it was not useful for ARCO staging of ONFH and treatment decisions. Based on this retrospective study, CT scan is not necessary when using the Revised ARCO Staging System

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by progressive cartilage degradation, synovial membrane inflammation, osteophyte formation, and subchondral bone sclerosis. Pathological changes in cartilage and subchondral bone are the main processes in OA. In recent decades, many studies have demonstrated that activin-like kinase 3 (ALK3), a bone morphogenetic protein receptor, is essential for cartilage formation, osteogenesis, and postnatal skeletal development. Although the role of bone morphogenetic protein (BMP) signalling in articular cartilage and bone has been extensively studied, many new discoveries have been made in recent years around ALK3 targets in articular cartilage, subchondral bone, and the interaction between the two, broadening the original knowledge of the relationship between ALK3 and OA. In this review, we focus on the roles of ALK3 in OA, including cartilage and subchondral bone and related cells. It may be helpful to seek more efficient drugs or treatments for OA based on ALK3 signalling in future.

Osteoarthritis (OA) is mainly caused by ageing, strain, trauma, and congenital joint abnormalities, resulting in articular cartilage degeneration. During the pathogenesis of OA, the changes in subchondral bone (SB) are not only secondary manifestations of OA, but also an active part of the disease, and are closely associated with the severity of OA. In different stages of OA, there were microstructural changes in SB. Osteocytes, osteoblasts, and osteoclasts in SB are important in the pathogenesis of OA. The signal transduction mechanism in SB is necessary to maintain the balance of a stable phenotype, extracellular matrix (ECM) synthesis, and bone remodelling between articular cartilage and SB. An imbalance in signal transduction can lead to reduced cartilage quality and SB thickening, which leads to the progression of OA. By understanding changes in SB in OA, researchers are exploring drugs that can regulate these changes, which will help to provide new ideas for the treatment of OA.

Cite this article: Bone Joint Res 2023;12(9):536–545.

Aims

Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism.

Introduction. Various methods to manage medial tibial defects in primary total knee arthroplasty (TKA) have been described. According to Vail TP, metal augmentation is usually indicated for defect depth of >10 mm of the medial tibial plateau. The outcomes of metal augmentation have been described as excellent. Nevertheless, we believe that it is mandatory to preserve as much of the bone as possible for future revision surgeries. Therefore, we performed autologous impaction bone grafting even for large bone defects (defect depth of ≥10 mm) in primary TKA. The objectives of this study are to describe our bone grafting technique in detail and to assess the radiological outcomes of the grafted bone. Methods. Between 2003 and 2011, 26 TKAs with autologous impaction bone grafting for ≥10 mm medial tibial defects were performed. The preoperative diagnoses were osteoarthritis in 17 knees, rheumatoid arthritis in 2 knees, osteonecrosis of the medial tibial condyle in 6 knees, and Charcot's joint in 1 knee. The average mediolateral width and depth of the medial tibial defects, measured after the horizontal osteotomy of the tibial articular surface, were 17.8 mm (range, 10–25 mm) and 12.0 mm (range, 10–23 mm), respectively. The average patient age at surgery was 73.2 years (range, 56–85 years). The patients were followed up for an average of 55 months (range 27–109 months). Bone grafting technique: Multiple drill holes (white arrow) were made on the floor of the defect (A) and a morselized cancellous bone was impacted using the grip end of a metal hammer (white asterisk) and firm manual pressure to fill the defect. Thus, the firm impaction prevented bone cement from entering the space between the graft and the tibial host bed. An assistant's index finger (black asterisk) was used as a bank (B). The tibial component was fixed on the grafted bone (white asterisk) with bone cement (C). Internal fixation devices were not required, and stem extension was used in only Charcot's joint (defect depth=23 mm). Aftertreatment was the same as that for the usual TKAs without bone defects. Results. In terms of clinical outcomes, no patient showed disturbances in walking ability at final follow-up. The average knee flexion angle was 114° (range, 95°–130°). The grafted bone was kept at the grafted area on the radiograms throughout the follow-up period. No absorption or collapse of the grafted bone was observed on the radiograms at the final follow-up. Usually, the grafted bone showed osteosclerotic changes around 2–3 months after TKA. Then, the osteosclerosis became weakened and the bony trabeculae could be detected in the grafted area. Finally, the grafted bone completely incorporated into the host bone in all knees with evidence of bony trabeculae crossing the interface by up to 1 year after surgery. The margin of the grafted area resembled bony cortex in 19 TKAs (73.1%). Conclusions. Our technique is easy, economic, and reproducible. It is an acceptable alternative to metal augmentation for large medial tibial defects in primary TKA

Radiological evaluation is crucial for interpretation of experimental osteomyelitis studies. Current scoring systems for radiologic evaluation of experimental osteomyelitis have limitations to demonstrate differences among treatment groups. Response of bone tissue to infection is a dynamic process; each radiological sign of osteomyelitis becomes prominent at different time points of disease. Analysing radiological criteria separately at different stages of the disease may provide better quantification of the response to treatment in experimental osteomyelitis rather than summation of these grades together. Osteomyelitis was induced with S.aureus in left tibias of 72 adult, wistar albino rats. Rats were assigned into six different treatment groups. Their radiograms were graded according to previously defined scoring systems, and each radiological criterion separately, at the third week of induction, and at the third and sixth week after treatment. Although periosteal reaction and diaphyseal widening demonstrate significant differences with three weeks of treatment, previously defined scoring systems could not find significant differences. At the sixth week of treatment, only one of the previously defined grading scales was able to differentiate significance among the treatment groups. Individual values of diaphyseal widening, osteolysis, BMC values were pointed out differences among the groups in the presence of osteomyelitis, confirmed by osteomyelitis. Formulation of radiological grading scales requires evaluation of periosteal elevation, diaphyseal widening, bone deformation, osteolysis, and osteosclerosis, individually. However, evaluation of these scores separately will multiply interpretations of future studies, and will make them more meaningful

Aims

The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs.

Paediatric acute leukemia may present with various clinical mifestations that mimic different orthopaedic conditions and can produce diagnostic confusion. In a retrospective study we reviewed the cases of 129 children (average age 6.2 years) affected by acute leukemia who had been seen between 1984 and 1999 at the Paediatric Haemato-Oncology Department of the University of Padova and had complete clinical and radiographic data. Almost all the patients (93.7%) had a variety of general signs and symptoms at presentation: weakness (44.3%); anorexia (32.7%); lethargy (7.8%); fever (64.2%); pallor (79.6%); bleeding (25.3%); lymphoadenopathy (58.8%); hepatosplenomeg-aly (75.6%). Thirty-seven patients (28.6%) had complaints related to the muscoloskeletal system when they were first seen including: pain (92.7%), swelling (29,7%), joint limitation (47.8%), limping (18.8%). Skeletal surveys were made for ninety-two (71.3%) of the patients when the diagnosis of leukemia was made, while the other thirty-seven (28.6%) had radiograms of the symptomatic areas. Seventy-five patients (58.1%) presented normal radiograms and fifty-four (41.9%) showed one or more abnormalities. Osteopenia was diagnosed in eight patients; lytic lesions were see in fourteen; metaphyseal bands in ten; periosteal reactions in four; osteosclerosis in two; mixed osteoscle-rosis and osteolysis in two; permetive pattern in eight; vertebral collapse in three children. During the course of the disease two patients developed avascular necrosis of the femoral head; one reported a pathologic femoral neck fracture; three presented collapse of one or more vertebral bodies. All these findings are not pathognomonic but the clinician should always include acute leukemia in the differential diagnosis of any child with unexplained radio-grafic changes and/or persistent skeletal pain

Aims

To evaluate inducing osteoarthritis (OA) by surgical destabilization of the medial meniscus (DMM) in mice with and without a stereomicroscope.

Aims

MicroRNA-183 (miR-183) is known to play important roles in osteoarthritis (OA) pain. The aims of this study were to explore the specific functions of miR-183 in OA pain and to investigate the underlying mechanisms.