Advanced-stage Osteoarthritis Research Articles

Rotational Acetabular Osteotomy for Advanced Osteoarthritis Secondary to Dysplasia of the Hip

Satisfactory intermediate and long-term results of rotational acetabular osteotomy for the treatment of early osteoarthritis secondary to developmental dysplasia of the hip have been reported. The purpose of this study was to examine the results of rotational acetabular osteotomy in patients with advanced osteoarthritis secondary to developmental dysplasia of the hip. We performed a retrospective review of the results of rotational acetabular osteotomy in forty-three patients (forty-three hips). All of the patients had radiographic evidence of advanced-stage osteoarthritis, defined as narrowing of the joint space with cystic radiolucencies and small osteophytes according to the staging system of the Japanese Orthopaedic Association. Forty-one patients were female, and two were male. The mean age was 43.8 years at the time of surgery, and the mean duration of follow-up was 8.5 years. Clinical follow-up was performed with use of the system of Merle d'Aubigné and Postel. The center-edge angle, acetabular roof angle, head lateralization index, and minimum width of the joint space were measured on radiographs made preoperatively, postoperatively, and at the time of final follow-up. Postoperative joint congruency was classified into four grades. The mean preoperative Merle d'Aubigné clinical score was 13.3 points, which improved to a mean of 15.4 points at the time of the latest follow-up (p < 0.0001). The mean center-edge angle improved from 0.7 degrees preoperatively to 29 degrees at three months postoperatively (p < 0.0001), the mean acetabular roof angle improved from 30 degrees to 11 degrees (p < 0.0001), the mean head lateralization index improved from 0.69 to 0.65 (p < 0.01), and the mean minimum width of the joint space improved from 2.2 to 2.5 mm (p < 0.0003). Ten hips had radiographic evidence of progression of osteoarthritis. Kaplan-Meier survivorship analysis, with radiographic signs of progression of osteoarthritis as the end point, predicted a ten-year survival rate of 72.2%. Rotational acetabular osteotomy for advanced osteoarthritis secondary to dysplasia of the hip in properly selected patients can improve clinical scores and is associated with a lack of radiographic signs of progression of osteoarthritis in most patients. Therapeutic Level IV.

New aspects of the pathogenesis of osteoarthritis: the role of fibroblast-like chondrocytes in late stages of the disease.

It is thought that the general increase in life expectancy will make osteoarthritis the fourth leading cause of disability by the year 2020. Even though the pathogenesis of idiopathic osteoarthritis has not been fully elucidated, the main features of the disease process are the altered interactions between the chondrocytes and their surrounding extracellular matrix. In the course of these disturbances, three types of chondrocytes are typically present in the pathologically altered extracellular matrix of the articular cartilage: healthy chondrocytes which are continually undergoing degeneration, degenerated cells which are continually being degraded and finally fibroblast-like chondrocytes which seem not to be influenced by this process and, therefore, are found in ever-increasing numbers. These fibroblast-like chondrocytes take part in tissue regeneration even in advanced stages of osteoarthritis, but only in as much as they form fibrocartilaginous or scar tissue, since, as we were able to show, they mainly synthesize collagen type I and not collagen type II, typical for healthy cartilage. However, we were further able to show that fibroblast-like chondrocytes also produce increasing amounts of the proteoglycans decorin and biglycan which physiologically are involved in the formation of collagen type II, as well as perlecan. These multifunctional fibroblast-like chondrocytes could present an ideal therapeutic starting point if they could be modified to synthesize the collagen type II typical for cartilage and to, thereby, contribute to reversing the damage of the joint cartilage that has occurred by the late stages of osteoarthritis.

Ｌｉｍｂｕｓ ｓｉｇｎと股関節鏡所見

To determine the relationship between pain at maximum flexion-rotation and the status of labral tear, a physical examination we refer to as “limbus sign” and hip arthroscopy were carried out. Between February 1998 and 1999, 30 patients with dysplastic osteoarthritis (2 males and 28 females) with a mean age of 42 years (range, 18 to 64 years), underwent 30 hip arthroscopies following physical examination. All hip joints arthroscoped demonstrated incomplete or complete detaching tears of the acetabular labrum in the weight-bearing area. Ten patients experienced pain during the maximum flexion-internal rotation test, and 10 patients were positive in the maximum flexion-external rotation test. Positive maximum flexion-external rotation test results correlated with early stage osteoarthritis. Positive maximum flexion-internal rotation test results were associated with incomplete detaching tears; however, there was no statistically significant relationship between maximum flexion-rotation test and arthroscopic findings of labral tears. This test may therefore be influenced by the degeneration of joint cartilage. We conclude that the maximum flexion-rotation test may be used to assess the labral tear of the acetabulum in early stage dysplastic hips, but not in advanced stage osteoarthritis.

Immunohistochemical Analysis of Type X-Collagen Expression in Osteoarthritis of the Hip Joint

Conflicting data have been reported on the spatial distribution of type X-collagen expression in osteoarthritis, and no concise data exist on a possible correlation between type X-collagen expression and clinical and radiological alterations. Well defined clinical and radiological data were compared with histopathological and immunohistochemical findings to investigate the expression of type-X collagen in osteoarthritis of the hip joint. Femoral heads were obtained in toto from 11 patients undergoing routine hip arthroplasty for femoral neck fractures (n = 3) or osteoarthritis (n = 8) and from 13 patients (age: 12 days to 69 years) without any evidence of hip-joint pathology. Whole coronal sections from the femoral head were decalcified for routine histology and immunohistochemical analysis with use of type-specific monoclonal antibodies to type-X collagen. Our results demonstrate that type-X collagen is consistently found in osteoarthritic cartilage and is absent from normal adult cartilage (including the region of calcified cartilage). Except for the occurrence of type-X collagen in the middle zone of articular cartilage in advanced stages of osteoarthritis, there is no specific change in the staining pattern or intensity for the collagen during osteoarthritis, particularly when the staining is related to clinical and radiological parameters. Hardly more than 20% of the extracellular matrix stained for type-X collagen; therefore, we suggest that, in most cases, this type of collagen may not play a direct biomechanical role in the weakening of osteoarthritic cartilage but rather may contribute indirectly to a disturbance of the disc biomechanics by altering matrix-molecule interaction. However, expression of type-X collagen may indicate a change in chondrocyte phenotype that consistently coincides with the formation of chondrocyte clusters, one of the first alterations in osteoarthritis visible on histologic examination.

Immunohistochemical analysis of type-X-collagen expression in osteoarthritis of the hip joint.

Conflicting data have been reported on the spatial distribution of type X-collagen expression in osteoarthritis, and no concise data exist on a possible correlation between type X-collagen expression and clinical and radiological alterations. Well defined clinical and radiological data were compared with histopathological and immunohistochemical findings to investigate the expression of type-X collagen in osteoarthritis of the hip joint. Femoral heads were obtained in toto from 11 patients undergoing routine hip arthroplasty for femoral neck fractures (n = 3) or osteoarthritis (n = 8) and from 13 patients (age: 12 days to 69 years) without any evidence of hip-joint pathology. Whole coronal sections from the femoral head were decalcified for routine histology and immunohistochemical analysis with use of type-specific monoclonal antibodies to type-X collagen. Our results demonstrate that type-X collagen is consistently found in osteoarthritic cartilage and is absent from normal adult cartilage (including the region of calcified cartilage). Except for the occurrence of type-X collagen in the middle zone of articular cartilage in advanced stages of osteoarthritis, there is no specific change in the staining pattern or intensity for the collagen during osteoarthritis, particularly when the staining is related to clinical and radiological parameters. Hardly more than 20% of the extracellular matrix stained for type-X collagen; therefore, we suggest that, in most cases, this type of collagen may not play a direct biomechanical role in the weakening of osteoarthritic cartilage but rather may contribute indirectly to a disturbance of the disc biomechanics by altering matrix-molecule interaction. However, expression of type-X collagen may indicate a change in chondrocyte phenotype that consistently coincides with the formation of chondrocyte clusters, one of the first alterations in osteoarthritis visible on histologic examination.

Human Cartilage from Late Stage Familial Osteoarthritis Transcribes Type II Collagen mRNA Encoding a Cysteine in Position 519

A single base change resulting in the substitution of Cys for Arg at position 519 of the type II collagen triple helix is a predisposing factor in the pathogenesis of a precocious-onset form of familial osteoarthritis associated with a mild chondrodysplasia. Cartilage obtained at the time of total knee replacement in a patient with the Arg-Cys 519 mutation was used to investigate the expression of Col2A1 alleles. Using PCR assisted amplification of mRNA with specific amplification of a region of Col2A1 message encompassing exons 31-34, followed by single strand conformation polymorphism and sequence analyses, we have found transcription products of both mutant and normal type II collagen alleles. Further analysis of the sequence of these exons provides evidence that the Arg-Cys 519 mutation arose independently in at least two of the three known affected families. The presence of both mutant and normal alleles of Col2A1 in cDNA derived from cartilage obtained from this patient suggests that Cys 519-containing type II collagen may continue to be produced even in advanced stages of osteoarthritis.

Chiari Pelvic Osteotomy for Advanced Stage Osteoarthritis of the Hip Joint

Chiari Pelvic Osteotomy for Advanced Stage Osteoarthritis of the Hip Joint

The natural course of osteoarthritis of the hip due to subluxation or acetabular dysplasia.

In 59 patients, 86 hips with subluxation or hip dysplasia were examined to determine the natural course of the condition and select suitable treatment. Thirty-three percent of the joints (13/39 hips) developed early osteoarthritis from pre-osteoarthritis within an average term of 9.2 years, while the remaining, sixty-six percent (31/47 hips) developed advanced-stage osteoarthritis from early osteoarthritis within an average term of 7.8 years. Patients were classified into advanced and non-advanced groups according to radiographic analysis of the advanced groups according to radiographic analysis of the advance of the disease and statistical analysis was performed. In pre-osteoarthritis, centre-edge angle, slope of the acetabular roof, acetabular head index, acetabular depth ratio and Japanese Orthopaedic Association (JOA) hip score were significant predictors, while in early osteoarthritis, a broken Shenton's line, cranial joint space and JOA score were significant. On the basis of multiple parameters, formulas for predicting development in patients with pre-osteoarthritis, those with early osteoarthritis, and all patients together were established, with an accuracy of 87%, 71%, and 68%, respectively.