Mature and activated osteoclasts exist in the synovium of rapidly destructive coxarthrosis

Rapidly destructive hip osteoarthritis: a diagnosis not to miss

This review illustrates the imaging features of rapidly destructive hip osteoarthritis (RDHO) across different imaging modalities. RDHO is a rare joint disease of unknown aetiology resulting in rapid deterioration of the hip joints. Patients often present with severe hip pain and can progress to complete joint destruction in 6 months to 3 years causing disability. Since its clinical and imaging features often overlap with other conditions, the diagnosis is easily missed in daily practice. The purpose of this paper is to outline the characteristic imaging features of RDHO, aiming to enhance awareness of this disease entity and promote timely treatment for patients. Sequential radiographs are particularly important in demonstrating the rapid progression of radiographic findings and with the early recognition of characteristic features, diagnosis can be made to avoid treatment delay. Although CT scan is not necessary for diagnosis, it is useful in evaluating the extent of joint destruction and guiding surgical planning. MRI can provide additional information and rule out other pathologies with similar symptoms. Overall, radiographs, CT and MRI are common modalities used in the evaluation of RDHO.

Increased bone resorption that outpaces increased bone formation: An important pathology of rapidly destructive coxarthrosis

Rapid joint destruction caused by rapidly destructive coxarthrosis (RDC) can increase surgical complexity and intraoperative blood loss. This single-center retrospective study investigates osteoporosis-related biomarkers for early RDC diagnosis and explores new treatment targets. We included 398 hip joints from patients who underwent total hip arthroplasty, examining medical records for preoperative patient demographics, bone mineral density of the hip and lumbar spine from dual-energy X-ray absorptiometry scans, and osteoporosis-related biomarkers including TRACP-5b, total P1NP, intact parathyroid hormone, and homocysteine. We compared RDC and osteoarthritis (OA) patients, and univariate analysis showed that RDC patients were older (p < 0.001) and had lower serum levels of albumin (p < 0.001) and higher serum levels of TRACP-5b, total P1NP (p < 0.001), and homocysteine (p = 0.006). Multivariable analysis showed that the ratio of serum TRACP-5b to total P1NP had a more significant difference in RDC patients than in OA patients (p = 0.04). Serum TRACP-5b levels were negatively correlated with the time between RDC onset and blood collection, and Japanese Orthopedic Association pain score. Receiver operating characteristic curve analysis revealed that the ratio of serum TRACP-5b to total P1NP had the highest area under the curve value. This study is the first to demonstrate that the ratio of serum TRACP-5b to total P1NP-increased bone resorption that outpaces increased bone formation-is significantly elevated in patients with RDC and that TRACP-5b is higher in the early stages of RDC. Inhibiting serum levels of TRACP-5b, activated osteoclasts, during early RDC may suppress disease progression.

Vitamin D Deficiency Is Frequent in Patients with Rapidly Destructive Osteoarthritis-Data from a Single-Center Analysis

BACKGROUND

Rapidly destructive osteoarthritis (RDO) of the hip joint is characterised by the rapid destruction of the femoral head with or without acetabular involvement. There has been increasing interest in this disease over the past years; however, the entity is still poorly understood, and its pathophysiology remains unknown. Yet, there is ample evidence today that increased bone metabolism might play a role in the onset and progression of the disease. Vitamin D is of utmost importance to maintain a balanced bone metabolism. However, whether vitamin D deficiency is involved in disease development remains to be elucidated. Further, the vitamin D status of patients with RDO has not yet been analysed. For this reason, the objective of this study was to assess the vitamin D status of patients with RDO. Moreover, the aim was to clarify whether there is a difference in the vitamin D status of patients with RDO compared with patients with primary osteoarthritis (OA).

METHODS

In this single-centre analysis, the 25(OH)D, PTH, and calcium levels of 29 patients who presented with RDO between 2020 and 2022 were assessed.

RESULTS

Altogether, 97% of patients (28/29) were vitamin D deficient, a further 3% (1/29) were vitamin D insufficient, and not a single patient presented with a sufficient vitamin D status. Notably, the vitamin D levels of RDO patients (mean = 11.04 ng/mL) were significantly lower than the vitamin D levels of patients with OA (mean = 22.16 ng/mL, p = 0.001).

CONCLUSION

In conclusion, we found a widespread and high rate of vitamin D deficiency in patients with RDO. Hence, we believe that 25(OH)D status should routinely be analysed in these patients.

Investigating sagittal spinopelvic alignment and equivalent stress on the femoral head in patients with rapidly destructive coxarthrosis

PURPOSE

Rapidly destructive coxarthrosis (RDC) is a rare syndrome of unknown etiology. This study evaluated sagittal spinopelvic alignment (SSPA) in patients with RDC and compared it with that in patients with hip osteoarthritis (HOA). In addition, finite element analysis (FEA) was performed to investigate the distribution of stress on the femoral head in RDC versus HOA.

METHODS

This retrospective study included patients who had undergone primary total hip arthroplasty for RDC (n = 33) and HOA (n = 99; age- and sex-matched to patients with RDC) at three hospitals from June 2014 to September 2020. Preoperative SSPA parameters and inflammatory blood markers were compared between the two groups. FEA on the computed tomography data was performed for four patients from each group with similar pelvic tilt (PT) and lateral center-edge angle (LCEA). The distribution of Drucker-Prager equivalent stress was assessed at the loaded area of the femoral head.

RESULTS

Patients with RDC had significantly higher PT, lower sacral slope, decreased lumbar lordosis (LL), higher sagittal vertical axis, and higher pelvic incidence minus LL than patients with HOA, indicating sagittal spinal imbalance. Blood test revealed patients with RDC had higher levels of inflammation markers than patients with HOA. FEA revealed no statistically significant difference in the degree of stress concentration or the maximum equivalent stress between the two groups when PT and LCEA were comparable.

CONCLUSION

Patients with RDC tend to have sagittally imbalanced spine. Decreased acetabular coverage of the femoral head may heighten mechanical load of the hip joint in patients with RDC.

T1 pelvic angle is associated with rapid progression of hip arthrosis

PURPOSE

To evaluate the association between global spinal malalignment and rapid progression of hip arthrosis.

METHODS

This was a retrospective, case-control study including 90 patients, contributing 90 hips, who underwent hemi- or total hip arthroplasty at our institution. For analysis, hips were classified into a rapid progression group, defined as ≥ 2 mm destruction of the femoral head or loss of the hip joint space within a 12-month period (n = 30), and a non-rapid progression group, defined by no observable hip disease progression over a period more than 12 months (n = 60). Logistic regression analysis identified factors that predicted rapid progression, with a receiver operating characteristic curve analysis used to confirm factors.

RESULTS

Significant between-group differences were identified for the following parameters: pelvic tilt (P = 0.002, PT), sagittal vertical axis (P = 0.002, SVA), and T1 pelvic angle (P < 0.001, TPA). On multiple logistic regression, PT (P = 0.002), SVA (P = 0.002), and TPA (P < 0.001) were predictive of a rapid progression on hip arthrosis, with the area under the curve being greater for TPA than PT (P = 0.035).

CONCLUSION

Global spinal alignment is associated with rapid progression of hip arthrosis. TPA could assist in identifying patients at risk for rapid progression of hip arthrosis, allowing for time management.

Inflammasome Activation in the Hip Synovium of Rapidly Destructive Coxopathy Patients and Its Relationship with the Development of Synovitis and Bone Loss

Rapidly destructive coxopathy (RDC), a rare disease of unknown etiology, is characterized by the rapid destruction of the hip joint. In the current study, the potential involvement of inflammasome signaling in the progression of RDC was investigated. Histopathologic changes and the gene expression of inflammasome activation markers in hip synovial tissues collected from patients with RDC were evaluated and compared with those of osteoarthritis and osteonecrosis of the femoral head patients. The synovial tissues of patients with RDC exhibited remarkable increases in the number of infiltrated macrophages and osteoclasts, and the expression of inflammasome activation markers was also increased compared with those of osteoarthritis and osteonecrosis of the femoral head patients. To further understand the histopathologic changes in the joint, a co-culture model of macrophages and synoviocytes that mimicked the joint environment was developed. Remarkably, the gene expression levels of NLRP3, GSDMD, IL1B, TNFA, ADMTS4, ADMTS5, MMP3, MMP9, and RANKL were significantly elevated in the synoviocytes that were co-cultured with activated THP-1 macrophages, suggesting the association between synovitis and inflammasome activation. Consistent with these findings, osteoclast precursor cells that were co-cultured with stimulated synoviocytes exhibited an increased number of tartrate-resistant acid phosphatase-positive cells, compared with cells that were co-cultured with non-stimulated synoviocytes. These findings suggest that the activation of inflammasome signaling in the synovium results in an increase in local inflammation and osteoclastogenesis, thus leading to the rapid bone destruction in RDC.

Rapidly Destructive Coxopathy With Femoral Head Fracture That Is Similar to a Slipped Capital Femoral Epiphysis in an Elderly Woman: A Case Report

Slipped capital femoral epiphysis (SCFE) generally occurs in adolescents but rarely in adults. Rapidly destructive coxopathy (RDC) is characterized by rapid joint destruction, including disruption of the joint at the femoral head and acetabulum as well as reduction of the joint space, within six to 12 months. The mechanism of RDC is likely multifactorial but has not yet been identified. Moreover, there are no reports of displaced femoral head fractures similar to an SCFE associated with RDC. We report a rare case of RDC with femoral head fracture that is similar to SCFE in an 86-year-old woman. Although the exact cause of the femoral head fracture is unknown, it can develop into RDC. Awareness of orthopedic surgeons regarding this condition is crucial for appropriate treatment, by monitoring the presentation of symptoms and imaging/radiographic findings.

Destructive Arthropathy of the Femoral Head

OBJECTIVES

Destructive arthropathy of the hip refers to noninfectious arthropathy causing extensive femoral head bone destruction. It has been described in the surgical literature using a variety of diagnostic criteria, but it remains a poorly defined entity.

METHODS

Cases of destructive arthropathy diagnosed at our institution between July 1, 2015, and December 31, 2019, were identified by a free text search of the radiology database. The medical record of each case was reviewed for possible causes of femoral head destruction, clinical presentation, laboratory values, imaging studies, and pathologic diagnoses. Imaging studies and pathology specimens were retrospectively reviewed.

RESULTS

Twenty femoral heads were identified in which there was 25% or greater destruction of the femoral head in the absence of infections, congenital disease, or inflammatory arthritis. Destructive arthropathy was characterized pathologically by fibromyxoid change of the marrow, aggregates of necrotic bone fragments, increased numbers of osteoclasts, increased trabecular destruction, and granuloma-like aggregates.

CONCLUSIONS

The histologic findings were distinctive. We postulate that a variety of preexisting conditions set in motion a cascade of tissue factors that led to bone destruction.

Association between sagittal spinopelvic alignment and femoral head destruction in the early stage of rapidly destructive coxopathy

Aims

This study aimed to evaluate sagittal spinopelvic alignment (SSPA) in the early stage of rapidly destructive coxopathy (RDC) compared with hip osteoarthritis (HOA), and to identify risk factors of SSPA for destruction of the femoral head within 12 months after the disease onset.

Methods

This study enrolled 34 RDC patients with joint space narrowing > 2 mm within 12 months after the onset of hip pain and 25 HOA patients showing femoral head destruction. Sharp angle was measured for acetabular coverage evaluation. Femoral head collapse ratio was calculated for assessment of the extent of femoral head collapse by RDC. The following parameters of SSPA were evaluated using the whole spinopelvic radiograph: pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), sagittal vertical axis (SVA), thoracic kyphosis angle (TK), lumbar lordosis angle (LL), and PI-LL.

Results

The HOA group showed higher Sharp angles compared with the RDC group. PT and PI-LL were higher in the RDC group than the HOA group. SS and LL were lower in the RDC group than the HOA group. No difference was found in PI, SVA, or TK between the groups. Femoral head collapse ratio was associated with PT, SS, SVA, LL, and PI-LL. A PI-LL > 20° and a PT > 30° correlated with greater extent of femoral head destruction by RDC. From regression analysis, SS and SVA were significantly associated with the femoral head collapse ratio within 12 months after disease onset.

Conclusion

Compared with HOA, RDC in the early stage correlated with sagittal spinopelvic malalignment. SS and SVA may partially contribute to the extent of femoral head destruction by RDC within 12 months after the onset of hip pain. The present study indicates a potential role of SSPA assessment in identification of RDC patients at risk for subsequent bone destruction. Cite this article: Bone Jt Open 2022;3(1):77–84.

Rapidly progressive idiopathic arthritis of the hip: incidence and risk factors in a controlled cohort study of 1471 patients after intra-articular corticosteroid injection

OBJECTIVE

Rapidly progressive idiopathic arthritis of the hip (RPIA) is defined by progressive joint space narrowing of > 2 mm or > 50% within 1 year. Our aims were to assess (a) the occurrence of RPIA after intra-articular steroid injection, and (b) possible risk factors for RPIA including: patient age, BMI, joint space narrowing, anesthetic and steroid selections, bone mineral density, and pain reduction after injection.

MATERIALS AND METHODS

A retrospective search of our imaging database identified 1471 patients who had undergone fluoroscopically guided hip injection of triamcinolone acetonide (Kenalog) and anesthetic within a 10-year period. Patient data, including hip DXA results and patient-reported pain scores, were recorded. Pre-injection and follow-up radiographs were assessed for joint space narrowing, femoral head deformity, and markers of osteoarthritis. Osteoarthritis was graded by Croft score. Associations between patient characteristics and outcome variables were analyzed.

RESULTS

One hundred six of 1471 injected subjects (7.2%) met the criteria for RPIA. A control group of 161 subjects was randomly selected from subjects who underwent hip injections without developing RPIA. Compared to controls, patients with RPIA were older, had narrower hip joint spaces, and higher Croft scores before injection (p < 0.05). Patients who developed RPIA did not differ from controls in sex, BMI, hip DXA T-score, anesthetic and steroid injectates, or pain improvement after injection.

CONCLUSION

We found that approximately 7% of patients undergoing steroid hip injection developed RPIA. More advanced patient age, greater joint space narrowing, and more severe osteoarthritis are risk factors for the development of RPIA after intra-articular steroid injection.

Defining the rate of, and factors influencing, radiographic progression of osteoarthritis of the canine hip joint

BACKGROUND

This study aimed to define the rate of progression of radiographic osteoarthritis (OA) of the canine hip joint and to describe factors affecting this progression.

METHODS

Dogs that underwent unilateral total hip replacement (THR) were reviewed for the evaluation of radiographic appearance of the non-operated hip joint over time. Standard extended ventrodorsal hip radiographs were taken preoperatively and postoperatively. All images were anonymized, randomized and scored using three different methods. The mean daily change between evaluations was calculated in each individual dog, and the effect of sex, age, body weight, open/closed status of the proximal femoral physis, preoperative severity of OA, time after surgery and their interactions, were investigated as potential influencing factors.

RESULTS

After reviewing the medical records, 163 dogs (468 images) met the inclusion criteria. Consistent across the three scoring systems, radiographic progression of OA was greater in younger (open physis) and spayed female dogs. A subset of seven patients (4.3%) had a faster progression of OA and was considered outliers. No dog was rated as outlier by all three scoring systems.

CONCLUSION

The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

Rapidly destructive coxopathy due to dialysis amyloidosis: a case report

Rapidly destructive coxopathy (RDC) is a disease that is sometimes seen in geriatric patients. A total hip arthroplasty (THA) is mostly chosen to treat the RDC, but few cases are known that received THAs due to RDC associated with dialysis amyloidosis. We report a case of RDC due to dialysis amyloidosis with special references to its pathophysiology. The case involved a 61-year-old male who had been on dialysis for seven years due to diabetic nephropathy. At his first visit, the radiographs showed collapse and flattening of the femoral head, which progressed within a month. Magnetic resonance imaging for the hip disclosed bone marrow edoema of the acetabulum and sclerosis of the subchondral bone of the femoral head. Biochemical analyses for the blood revealed high inflammatory reactions with elevated C-reactive protein and white blood cell count, but the joint fluid cultures were negative for general bacteria, tubercle bacillus, and nontuberculous mycobacteria. As he did not have gastrointestinal disorders or inflammatory arthritis other than the left hip and no disease that caused elevated inflammatory reactions was observed, we diagnosed the patient with RDC due to dialysis amyloidosis, and a THA was performed. Pathological findings for the synovium collected during surgery showed infiltration of the inflammatory mononuclear cells and vascular hyperplasia. The synovial tissues were extensively stained with an antibody to β2-microglobulin. Many tartrate-resistant acid phosphatase-positive multinucleated cells were also observed in the synovium. One year after surgery, his left hip pain disappeared and he returned to work.

Bone turnover markers in the early stage of rapidly progressive osteoarthritis of the hip

OBJECTIVE

Previous reports have demonstrated that patients with end-stage rapidly progressive osteoarthritis of the hip (RPOH) show significantly higher serum levels of bone turnover markers than those with osteoarthritis (OA). However, the characteristics of bone turnover markers in the early stage of RPOH remain unclear. This study aimed to elucidate the association of bone turnover markers with disease progression in the early stage of RPOH.

METHODS

This study included 29 postmenopausal female patients with joint space narrowing >2 mm demonstrated on a series of radiographs and computed tomography within 1 year following the onset of hip pain. The study also included 9 postmenopausal female patients with hip OA secondary to developmental dysplasia showing femoral head destruction. Cortical thickness index (CTI) associated with bone mineral density of the hip was analyzed. Serum concentrations of tartrate-resistant acid phosphatase-5b (TRACP-5b) and bone alkaline phosphatase (BAP) were evaluated.

RESULTS

RPOH was classified into two types on the basis of the absence (type 1, n=13) or presence (type 2, n=16) of subsequent destruction of the femoral head within 1 year following disease onset. TRACP-5b and BAP significantly increased in RPOH type 2 compared with type 1 and OA. Receiver operating characteristic curve analyses indicated that TRACP-5b and BAP could differentiate RPOH type 2 from type 1 within 1 year following the onset. CTI showed no difference among the RPOH types 1 and 2 and OA.

CONCLUSION

High serum levels of bone turnover markers may be associated with destruction of the femoral head in the early stage of RPOH.

Characterization of rapidly progressive osteoarthritis of the hip in its early stage

OBJECTIVE

This study aimed to characterize the process of disease progression in the early stage of rapidly progressive osteoarthritis of the hip (RPOH) and clarify its association with potential pathological factors of RPOH.

METHODS

This monocentric retrospective study included 41 female patients who met the criteria for RPOH, chondrolysis >2 mm during 12 months from the onset of hip pain based on a series of radiographs and computed tomography. This study also included 9 female patients with osteoarthritis secondary to developmental dysplasia of the hip (DDH) who demonstrated chondrolysis >2 mm during 12 months from the onset of hip pain. Cortical thickness index (CTI) correlated with bone mineral density of the hip, pelvic tilt, and serum concentrations of matrix metalloproteinase (MMP)-3 were analyzed.

RESULTS

RPOH was classified into two types based on the absence (type 1, n=17) and presence (type 2, n=24) of subsequent femoral head destruction within 12 months after the onset of hip pain. MMP-3 significantly increased in RPOH type 2 compared with type 1 and DDH. Increased posterior pelvic tilt was found in RPOH type 2 compared with DDH. Logistic regression and receiver operating characteristic curve analyses indicated that MMP-3 may be associated with differentiation between RPOH types 1 and 2. No difference was found in the CTI between the RPOH types and DDH.

CONCLUSION

Disease progression of RPOH during 12 months after the onset of hip pain could be classified into two distinct types based on the absence (type 1) and presence (type 2) of femoral head destruction in association with MMP-3 and pelvic tilt as biological and mechanical factors, respectively. MMP-3 may be helpful to differentiate these two types in the early stage of RPOH.

Co-culture of osteochondral explants and synovial membrane as in vitro model for osteoarthritis

The purpose of the current study was to establish an in vitro model for osteoarthritis (OA) by co-culture of osteochondral and synovial membrane explants. Osteochondral explants were cultured alone (control-1) or in co-culture with synovial membrane explants (control-2) in standard culture medium or with interleukin-1β (IL1β) and tumor necrosis factor (TNFα) added to the culture medium (OA-model-1 = osteochondral explant; OA-model-2 = osteochondroal-synovial explant). In addition, in OA-model groups a 2-mm partial-thickness defect was created in the centre of the cartilage explant. Changes in the expression of extracellular matrix (ECM) genes (collagen type-1 (Col1), Col2, Col10 and aggrecan) as well as presence and quantity of inflammatory marker genes (IL6, matrix metalloproteinase-1 (MMP1), MMP3, MMP13, a disintegrin and metalloproteinase with-thrombospondin-motif-5 (ADAMTS5) were analysed by immunohistochemistry, qPCR and ELISA. To monitor the activity of classically-activated pro-inflammatory (M1) versus alternatively-activated anti-inflammatory/repair (M2) synovial macrophages, the nitric oxide/urea ratio in the supernatant of osteochondral-synovial explant co-cultures was determined. In both OA-model groups immunohistochemistry and qPCR showed a significantly increased expression of MMPs and IL6 compared to their respective control group. ELISA results confirmed a statistically significant increase in MMP1and MMP3 production over the culturing period. In the osteochondral-synovial explant co-culture OA-model the nitric oxide/urea ratio was increased compared to the control group, indicating a shift toward M1 synovial macrophages. In summary, chemical damage (TNFα, IL1β) in combination with a partial-thickness cartilage defect elicits an inflammatory response similar to naturally occurring OA in osteochondral explants with and without osteochondral-synovial explant co-cultures and OA-model-2 showing a closer approximation of OA due to the additional shift of synovial macrophages toward the pro-inflammatory M1 phenotype.

Osteoclast-related markers in the hip joint fluid with subchondral insufficiency fracture of the femoral head

Similar to the radiological findings in rapidly destructive arthrosis of the hip joint (RDA), subchondral insufficiency fracture of the femoral head (SIF) can result in progressive femoral head collapse of unknown etiology. We thus examined the osteoclast activity of hip joint fluid in SIF with progressive collapse in comparison with that in RDA. Twenty-nine hip joint fluid samples were obtained intraoperatively with whole femoral heads from 12 SIF patients and 17 RDA patients. SIF cases were classified into subgroups based on the presence of ≥2 mm collapse on preoperative radiographs: SIF with progressive collapse (n = 5) and SIF without progressive collapse (n = 7). The levels of tartrate-resistant acid phosphatase (TRACP)-5b, interleukin-8, vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 were measured. The number of multinuclear giant cells at the subchondral region was histopathologically assessed using mid-coronal slice of each femoral head specimen. The median levels of all markers and the median number of multinuclear giant cells in SIF with progressive collapse were significantly higher than those in SIF without progressive collapse, while there were no significant differences in SIF with progressive collapse versus RDA. Regression analysis showed that the number of multinuclear giant cells was positively correlated with the level of TRACP-5b in joint fluid. The present study demonstrated the possible association of increased osteoclast activity with the existing condition of progressive collapse in SIF, which was quite similar to the findings in RDA, indicating that increased osteoclast activity may reflect the condition of progressive collapse in SIF as well as RDA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2987-2995, 2018.

What drives osteoarthritis?-synovial versus subchondral bone pathology

Subchondral bone and the synovium play an important role in the initiation and progression of OA. MRI often permits an early detection of synovial hypertrophy and bone marrow lesions, both of which can precede cartilage damage. Newer imaging modalities including CT osteoabsorptiometry and hybrid SPECT-CT have underlined the importance of bone in OA pathogenesis. The subchondral bone in OA undergoes an uncoupled remodelling process, which is notably characterized by macrophage infiltration and osteoclast formation. Concomitant increased osteoblast activity leads to spatial remineralization and osteosclerosis in end-stage disease. A plethora of metabolic and mechanical factors can lead to synovitis in OA. Synovial tissue is highly vascularized and thus exposed to systemic influences such as hypercholesterolaemia or low grade inflammation. This review aims to describe the current understanding of synovitis and subchondral bone pathology and their connection in OA.

A case of rapidly destructive osteoarthritis of the hip with onset of less than six weeks

INTRODUCTION

Rapidly destructive osteoarthritis is characterized by a severe destruction of the hip joint developing over short periods of time. However, to date, there is no agreement on the biological process that triggers this condition. The aim of this report is to present a case of rapidly destructive osteoarthritis.

CASE REPORT

We report a case of a 76 year-old female who presented with hip pain of sudden onset and normal X-rays. Six weeks later she presented with increased pain intensity, functional limitation and evidence of a collapse of the femoral head in the X-rays.

DISCUSSION

Rapidly destructive osteoarthritis of the hip is a complex entity that might be more frequent than previously described and which clinical course could vary between few weeks and several months. In order to make an accurate diagnosis, other causes of massive destruction of the joint should be excluded.

Characteristics of bone turnover markers in rapidly destructive coxopathy

The purpose of this study was to clarify bone turnover marker levels in rapidly destructive coxopathy (RDC). Twenty patients with RDC (mean age, 72 ± 11 years; 3 men, 17 postmenopausal women), 111 with osteoarthritis (OA) (age, 60 ± 10 years; 15 men, 13 premenopausal women, 83 postmenopausal women), and 18 with osteonecrosis of femoral head (ON) (55 ± 14 years; 11 men, 3 premenopausal women, 4 postmenopausal women), and 100 patients with femoral neck fracture (FNF) (81 ± 10 years; 27 men, 73 postmenopausal women) were included. Serum tartrate-resistant acid phosphatase 5b (TRACP-5b), bone alkaline phosphatase (BAP), matrix metalloproteinase-3 (MMP-3) levels, and bone mineral density (BMD) of proximal femur and lumbar spine were investigated. TRACP-5b levels were significantly higher in RDC than in OA and ON, whereas BAP levels were higher in RDC than in OA (P < 0.05). MMP-3 levels were higher in RDC and ON than in OA (P < 0.05). TRACP-5b were higher in RDC than OA (P < 0.05) and FNF (P < 0.05) in performing propensity score matching; there were no differences in BMD between RDC and OA. TRACP-5b showed the largest area under the curve (AUC, 0.82) according to receiver operating characteristic (ROC) curve analysis for diagnosing RDC against OA and ON. AUCs of BAP and MMP-3 were 0.78 and 0.74. The respective sensitivities and specificities were 70.0 % and 85.3 % for TRACP-5b (cutoff, 623 mU/dl), 95.0 % and 57.1 % for BAP (13.8 U/l), and 70.0 % and 76.4 % for MMP-3 (52.7 ng/ml). The lack of differences in BMD suggested that high bone turnover marker levels may reflect osteoclast cell activation in RDC hips. Serum TRACP-5b and BAP could be RDC markers.

Unexplained "massive osteolysis of femoral head" (MOFH) after acetabular fracture: occurrence and suggested patho-etiology

Background We observed cases of extensive osteolysis of the femoral head following acetabular fractures even though the original fracture did not involve the femoral head or neck. This observation has been called massive osteolysis of the femoral head (MOFH). Purpose To evaluate the clinical and imaging features of MOFH to gain a better understanding of its patho-etiology. Material and Methods We retrospectively collected cases of acetabular fractures seen over a period of 10 years and evaluated the clinical features and imaging characteristics. The findings were compared with the features of other complications such as osteonecrosis, rapidly progressive osteoarthritis, or post-traumatic osteolysis. Results Fifteen patients (M:F ratio 9:6; mean age, 61.6 years) out of 244 had MOFH (prevalence: 6.1%). Motor vehicle collision and falls were the most common mechanisms of injury. The time interval for developing MOFH was in the range of 1-18 months after the initial injury. Patterns of femoral head osteolysis varied from eccentric (12 cases) to transcervical (3 cases). Four cases of eccentric osteolysis developed high-degree of osteolysis. MOFH was observed near the surgical hardware in 6/15 cases. One biopsy specimen did not reveal typical features of osteoarthritis or avascular necrosis. Conclusion MOFH appears to be a distinct entity from avascular necrosis or rapidly progressive osteoarthritis. It is suggested that MOFH is a variant of post-traumatic osteolysis that is evident in a subset of patients.

Comparison of Perioperative Blood Loss in Primary Non-cemented Total Hip Arthroplasty for Rapidly Destructive Coxarthrosis and Osteonecrosis of the Femoral Head

Purpose

The purpose of this study is to compare the perioperative blood loss in primary non-cemented total hip arthroplasty (THA) performed for rapidly destructive coxarthrosis (RDC) with the perioperative blood loss in primary non-cemented THA for typical osteonecrosis of the femoral head (ONFH).

Materials and Methods

From January 2000 to December 2013, 19 patients were diagnosed with RDC (group 1) and 40 patients were diagnosed typical Ficat stage IV ONFH (group 2), comparison of perioperative blood loss between group 1 and group 2 in primary noncemented THA was done. Patients with preoperative usage of steroid or anticoagulants medication and with hemodynamic abnormal blood test results were excluded. The blood loss was measured up to the fifth post operation day and calculated with formula proposed by Mercuriali, Inghilleri and Nadler.

Results

Non-compensated blood loss calculated in milliliters of red blood cells was 362 mL (standard deviation [SD], 187; range, 77-675) in group 1 and 180 mL (SD, 145; range, 53-519) in group 2. Compensated blood loss was 630 mL (SD, 180; range, 380-760) in group 1 and 503 mL (SD, 260; range, 190-1, 505) in group 2. The total blood loss after primary non-cemented THA is greater when surgery is performed for RDC than for ONFH, with the volume of 992 mL (SD, 300; range, 457-1, 434) in group 1 and 683 mL (SD, 360; range, 226-1, 975) in group 2 respectively.

Conclusion

Total perioperative blood loss was significantly greater in RDC than in ONFH in primary non-cemented THA.

Characterization of multinucleated giant cells in synovium and subchondral bone in knee osteoarthritis and rheumatoid arthritis

Background

Multinucleated giant cells have been noticed in diverse arthritic conditions since their first description in rheumatoid synovium. However, their role in the pathogenesis of osteoarthritis (OA) or rheumatoid arthritis (RA) still remains broadly unknown. We aimed to study the presence and characteristics of multinucleated giant cells (MGC) both in synovium and in subchondral bone tissues of patients with OA or RA.

Methods

Knee synovial and subchondral bone samples were from age-matched patients undergoing total joint replacement for OA or RA, or non-arthritic post mortem (PM) controls. OA synovium was stratified by histological inflammation grade using index tissue sections. Synovitis was assessed by Krenn score. Histological studies employed specific antibodies against macrophage markers or cathepsin K, or TRAP enzymatic assay.

Results

Inflamed OA and RA synovia displayed more multinucleated giant cells than did non-inflamed OA and PM synovia. There was a significant association between MGC numbers and synovitis severity. A TRAP negative/cathepsin K negative Langhans-like subtype was predominant in OA, whereas both Langhans-like and TRAP-positive/cathepsin K-negative foreign-body-like subtypes were most commonly detected in RA. Plasma-like and foam-like subtypes also were observed in OA and RA synovia, and the latter was found surrounding adipocytes. TRAP positive/cathepsin K positive osteoclasts were only identified adjacent to subchondral bone surfaces. TRAP positive osteoclasts were significantly increased in subchondral bone in OA and RA compared to PM controls.

Conclusions

Multinucleated giant cells are associated with synovitis severity, and subchondral osteoclast numbers are increased in OA, as well as in RA. Further research targeting multinucleated giant cells is warranted to elucidate their contributions to the symptoms and joint damage associated with arthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0664-5) contains supplementary material, which is available to authorized users.

Total Hip Arthroplasty for Rapidly Destructive Coxarthrosis in a Patient with Severe Platelet Deficiency due to Liver Cirrhosis and Immune Thrombocytopenic Purpura

Rapidly destructive coxarthrosis (RDC) causes rapid and extreme destruction of the hip joint, which was reported by Postel and Kerboull. RDC is commonly unilateral and occurs mostly in elderly women. Immune thrombocytopenic purpura (ITP) is characterized by a low platelet count that is the result of both immune-mediated platelet destruction and suppression of platelet production. In patients with ITP undergoing surgery, bleeding associated with a low preoperative platelet count can lead to unsuccessful outcomes. To the best of our knowledge, there has been only one report describing total hip arthroplasty (THA) for patients with ITP and there have been no reports of THA for RDC with a very low platelet count due to liver cirrhosis (LC) and ITP. We report the case of a patient who had right RDC and a very low platelet count due to LC and ITP in whom THA was successfully performed. Furthermore, this case was also unique in that her platelet count increased after THA. THA for right RDC might resolve ITP by relieving inflammation of the right hip since her platelet count recovered after THA.

Early MRI and intraoperative findings in rapidly destructive osteoarthritis of the hip: A case report

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Magnetic resonance imaging of our rapidly destructive hip osteoarthritis case showed a bone-marrow edema pattern not only in the femoral head but also in the acetabulum.

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The concentration of stress on the subchondral bone due to inversion of the acetabular labrum may lead to fracture of the femoral head and acetabulum beneath the cartilage.

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Inversion of the acetabular labrum may be a mechanism of rapidly destructive hip OA.

Introduction

The pathophysiology of rapidly destructive hip osteoarthritis (OA) of the hip is still unclear. Also, there have been only few reports on the initial stage of the disease. We report a case of an initial-stage rapidly destructive hip OA, documented by magnetic resonance imaging and intraoperative findings.

Presentation of case

A 77-year-old woman reported left hip pain without any antecedent trauma. Initial radiographs showed no obvious abnormality. After 4 months of conservative therapy, radiographs showed progressive joint-space narrowing and T₁-weighted magnetic resonance images revealed a bone-marrow edema pattern not only on the femoral head but also on the lateral side of the acetabulum. Then during total hip arthroplasty, we found extensive inversion of the anterosuperior portion of the acetabular labrum, and the location was mostly consistent with the bone-marrow edema lesions in the femoral head and acetabulum.

Discussion

Several theories for the etiology of rapidly destructive hip OA have been proposed, including idiopathic chondrolysis, abnormal immunoreaction, intra-articular deposition of hydroxyapatite crystals, and subchondral insufficiency fracture. One of the reasons rapidly destructive hip OA is still considered idiopathic is the lack of reports regarding the initial stage of the disease. Our report is the first to demonstrate magnetic resonance imaging for initial-stage disease with intraoperative findings before collapse of the femoral head.

Conclusion

Inversion of the acetabular labrum may be a mechanism of rapidly destructive hip OA.

Rapid hip osteoarthritis development in a patient with anterior acetabular cyst with sagittal alignment change

Rapidly destructive coxarthrosis (RDC) is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA) development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.

[Detritic synovitis and rare skeletal diseases]

Detritic synovitis represents a common finding in routine orthopedic pathology. Microscopically, the synovium displays cartilaginous and bony fragments in the synoviocyte layer or within the subsynovial soft tissues associated with resorptive changes. In the vast majority of cases, detritic synovitis is associated with conditions leading to the destruction of articular cartilage and subchondral bone, such as severe osteoarthritis, collapsed avascular necrosis, diabetes mellitus, Charcot arthropathy or non-union fractures. The objective of this article is to review the literature regarding the microscopic findings in ochronosis, rapidly destructive hip disease and apatite crystal depositions that can enable a confident diagnosis or a limited differential diagnosis of detritic synovitis.

Massive accumulation of osteoclastic giant cells in rapid destructive hip disease

The term rapid destructive hip disease (RDHD) designates a rare coxarthropathy characterized by a rapid destruction of the femoral head within a few weeks to several months. The etiology and pathogenesis of RDHD are not understood. The goal of this study was to define the histological and histomorphometric hallmarks of RDHD to provide a basis for a deeper understanding of the underlying mechanisms. Fifteen consecutive RDHD patients (mean age 78.9 ± 6.4 years, 14 females) demonstrated the characteristic radiographic appearance of vanishing femoral head bone stock without signs of reactive anabolic changes. Histologic and histomorphometric analyses revealed severe bone resorption with significantly increased numbers of morphologically altered giant osteoclasts, the formation of giant cell granulomas both in bone marrow and the synovium and significantly increased osteoblast numbers and osteoid as compared to controls with primary osteoarthritis (OA). These results suggest that in RDHD, an unknown stimulus leads to a massive activation of osteoclasts and this in turn provokes a reactive increase in osteoblast activity that is too weak to counteract the rapid destruction of the hip, thus providing a rationale for a prospective systematic search for the stimuli upstream of the massively increased osteoclast activation in RDHD.

Importance of synovitis in osteoarthritis: evidence for the use of glycosaminoglycans against synovial inflammation

OBJECTIVES

After detailing the different aspects of synovial inflammation (i.e., cellular, biochemical, and vascular) and based on the current knowledge, the aim of this review was to collect the available in vitro and in vivo data regarding the potency of some glycosaminoglycan (GAG) compounds to target synovial inflammation, an important aspect of osteoarthritis.

METHODS

The first part of the review corresponds to a qualitative review of the inflammatory status of OA synovial membrane. The second part corresponds to a systematic review of the literature regarding the potential effects of some GAGs on the previously described phenomenon.

RESULTS

The synovial aspect of the inflammatory status of OA has been detailed. Chondroitin sulfate has demonstrated to control the three aspects of synovial membrane inflammation: cell infiltration and activity, biochemical mediators release, and angiogenesis. Glucosamine is also active on both cellular and molecular aspects of the inflammatory reaction. Hyaluronic acid seems to be anti-inflammatory in its native form, while products of degradation are reported to be pro-angiogenic.

CONCLUSION

Much evidence suggests that some of the studied GAG compounds could target different aspects of synovitis. Some of them could be considered in combination therapy since they exhibit complementary properties. Most of the studies have concentrated on articular cartilage and chondrocytes. In order to achieve a structure modification, one may now consider all joint tissues and investigate the drug potency on all of them. Potent treatment should trigger the most important features of OA: cartilage degradation, subchondral bone sclerosis, and all aspects of synovial inflammation.

Synovial joint fluid cytokine levels in hip disease

OBJECTIVE

The purpose of this study was to evaluate cytokine level characteristics in the hip joint fluid, including rapidly destructive coxopathy (RDC), OA, osteonecrosis (ON) of the femoral head and RA.

METHODS

Thirty-three hips with RDC, 57 with OA, 36 with ON and 10 with RA were included in the study. OA hips were divided into two groups: 20 hips with early OA without joint space narrowing and 37 hips with terminal OA. ON hips were divided into three groups: 13 hips with <3 mm collapse, 14 hips with >3 mm collapse and 9 hips with terminal ON. Joint fluid was collected during surgery. Cytokine levels including IL-1β, IL-6, IL-8 and TNF-α were measured using homogeneous time-resolved fluorescence.

RESULTS

All measured cytokine levels in RDC were significantly higher than those in OA (P < 0.05). Terminal OA showed higher cytokine levels than those in early OA (P < 0.05). IL-6 and TNF-α levels in the ON group with >3 mm collapse were higher than those found in the ON group with <3 mm collapse. In comparing cytokine levels between RDC, terminal OA, RA and terminal ON, RDC showed significantly higher IL-8 levels than terminal OA and RA (P < 0.05).

CONCLUSION

IL-8 levels in RDC were higher than in the other hip diseases. The IL-8 level may reflect the aggressiveness of joint destruction in RDC, and IL-6 and TNF-α levels may also reflect ongoing destruction in OA and ON.

The role of synovitis in pathophysiology and clinical symptoms of osteoarthritis

Osteoarthritis (OA), one of the most common rheumatic disorders, is characterized by cartilage breakdown and by synovial inflammation that is directly linked to clinical symptoms such as joint swelling, synovitis and inflammatory pain. The gold-standard method for detecting synovitis is histological analysis of samples obtained by biopsy, but the noninvasive imaging techniques MRI and ultrasonography might also perform well. The inflammation of the synovial membrane that occurs in both the early and late phases of OA is associated with alterations in the adjacent cartilage that are similar to those seen in rheumatoid arthritis. Catabolic and proinflammatory mediators such as cytokines, nitric oxide, prostaglandin E(2) and neuropeptides are produced by the inflamed synovium and alter the balance of cartilage matrix degradation and repair, leading to excess production of the proteolytic enzymes responsible for cartilage breakdown. Cartilage alteration in turn amplifies synovial inflammation, creating a vicious circle. As synovitis is associated with clinical symptoms and also reflects joint degradation in OA, synovium-targeted therapy could help alleviate the symptoms of the disease and perhaps also prevent structural progression.

Bilateral chondrolysis of the hip following liver transplantation

A 32-year-old woman with bilateral hip chondrolysis diagnosed 2 years following allogeneic liver transplantation is described. Severe osteoarthritis was demonstrated on physical examination, serial radiographs and magnetic resonance imaging. Only four cases of chondrolysis in solid organ recipients have been described in the literature.