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 in hip joint fluid in SIF with progressive collapse in comparison to 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 ≥2mm 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. Numbers of multinuclear giant cells at the subchondral region were assessed histopathologically using mid-coronal slices of each femoral head specimen. Median levels of all markers and median numbers 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 correlated positively with the level of TRACP-5b in joint fluid. This study suggests an association of increased osteoclast activity with the existing condition of progressive collapse in SIF, which was quite similar to the findings in RDA. Therefore, high activation of osteoclast cell may reflect the condition of progressive collapse in SIF as well as RDA.
Osteophytes are products of active endochondral and intramembranous ossification, and therefore could theoretically provide significant efficacy as bone grafts. In this study, we compared the bone mineralisation effectiveness of osteophytes and cancellous bone, including their effects on secretion of growth factors and anabolic effects on osteoblasts. Osteophytes and cancellous bone obtained from human patients were transplanted onto the calvaria of severe combined immunodeficient mice, with Calcein administered intra-peritoneally for fluorescent labelling of bone mineralisation. Conditioned media were prepared using osteophytes and cancellous bone, and growth factor concentration and effects of each graft on proliferation, differentiation and migration of osteoblastic cells were assessed using enzyme-linked immunosorbent assays, MTS ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)) assays, quantitative real-time polymerase chain reaction, and migration assays.Objectives
Methods
Transtrochanteric curved varus osteotomy is one of the effective joint-preserving operations for osteonecrosis (ON) of the femoral head. We correlated various factors with the radiological outcome of this procedure. We reviewed 74 hips in 63 patients who had a minimum follow-up of 5 years after transtrochanteric curved varus osteotomy for the treatment of ON. There were 28 men and 35 women who had a mean age of 33 years (range, 15 to 68 years) at the time of surgery. Clinical assessment was made based on the Harris hip score (HHS). Radiographically, we investigated various factors; affected lesion, stage and type (localization of the necrotic lesion) of ON, varus degree, post-operative intact ratio, progression of collapse, and joint-space narrowing. On the basis of postoperative radiographs, the hips were divided into 2 groups (Group I: either the progression of collapse or joint-space narrowing, Group II: neither progression of collapse or joint-space narrowing). The related factors with radiological outcome were analyzed by using multivariate analysis (Stepwise discriminant analysis).Introduction
Methods
The objective of this study was to verify the long-term outcome of transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH) in young patients with systemic lupus erythematosus (SLE). Consecutive series of 21 symptomatic ONFH patients with SLE (33 hips), aged 20 to 40 years, underwent ARO between 1980 and 1988. We reviewed the cases of 16 patients (25 hips), which represents a 76% rate of follow-up. Patients included 4 men and 12 women who had a mean age of 29 years at the time of surgery. A Kaplan-Meier curve was used for the survivorship analysis of ARO. Patients with surviving hips were evaluated by the modified Oxford hip score and the Medical Outcomes Study Short Form 36 (SF-36).Introduction
Methods
Subchondral insufficiency fracture of the femoral head (SIF) is a recently proposed concept. It is generally seen in elderly people, however, some young adults have also been reported to suffer from this fracture. The purpose of this study was to investigate the clinical results of a transtrochanteric anterior rotational osteotomy (ARO) performed in young adults with SIF. This study focused on young SIF cases (age range from 10 to 29 years). Five patients were diagnosed to have SIF at our institution and conservative treatment was initially performed. The symptoms resolved in 1 case while the other 4 cases showed progression of a collapse. In these 4 cases, ARO was performed, since the fractured area was located in the anterosuperior portion of the femoral head. The average age of the patients was 22 years (range, 16 to 29 years) at the time of surgery, consisting of 2 men and 2 women.Introduction
Methods
Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-intensity band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-intensity band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low intensity band on the T1-weighted magnetic resonance images were also examined, with regard to the band length, band thickness and band length ratio; which is defined as a proportion of the band length to the weight-bearing portion of the femoral head.Introduction
Methods
Subchondral insufficiency fracture (SIF) needs to be differentiated from osteonecrosis. The purpose of this study was to evaluate the imaging and histopathological findings of patients 60 years or older with radiological evidence of subchondral collapse of the femoral head. We reviewed 77 consecutive hips in 56 patients aged 60 years or older, which showed subchondral collapse on radiographs. According to the shapes of low-intensity bands on T1-weighted images of magnetic resonance imaging (MRI), the patients were divided into 2 groups. Group A showed a concavity of the articular surface: characteristic appearances of osteonecrosis, and Group B showed an irregular convexity of the articular surface: characteristic appearances of SIF.Introduction
Methods
In Japan, idiopathic osteonecrosis of the femoral head (ONFH) is designated as a specified rare and intractable disease in patients for whom medical care is subsidized through the Specified Disease Treatment Research Program. Each patient is approved for the subsidy based upon a prefectural governmental review after filing an application together with a clinical research form documenting the patient's medical history, laboratory/clinical findings, and treatment. The purpose of this study was to conduct a fact-finding study of ONFH patients in the Fukuoka Prefecture based on clinical research forms of the Specified Disease Treatment Research Program. The distribution by gender and age of ONFH patients who filed an application for subsidy under this program between 1999 and 2008 was investigated on the basis of clinical research forms in the Fukuoka Prefecture. For comparative purposes, we also investigated the distribution by gender and age of ONFH patients who had a final diagnosis of ONFH at our institution during the past three years.Background
Methods
We have studied the effect of hydroxyapatite (HA) coating in 15 ovariectomised and 15 normal rats which had had a sham procedure. Twenty-four weeks after operation, HA-coated implants were inserted into the intramedullary canal of the right femur and uncoated implants into the left femur. The prostheses were removed four weeks after implantation. Twelve specimens in each group had mechanical push-out tests. Sagittal sections of the other three were evaluated by SEM. The bone mineral density (BMD) of the dissected left tibia was measured by dual-energy x-ray absorptiometry. The difference in BMD between the control and ovariectomised tibiae was 35.01 mg/cm2 (95% CI, 26.60 to 43.42). The push-out strength of the HA-coated implants was higher than that of the uncoated implants in both groups (p <
0.0001), but the HA-coated implants of the ovariectomised group had a reduction in push-out strength of 40.3% compared with the control group (p <
0.0001). Our findings suggest that HA-coated implants may improve the fixation of a cementless total hip prosthesis but that the presence of osteoporosis may limit the magnitude of this benefit.
Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1α), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1α expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1α in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1α were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1α inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.
We exposed human macrophages isolated from the peripheral blood of healthy donors to metal and bone-cement particles from 0.2 to 10 μm in size. Zymography showed that macrophages exposed to titanium alloy and polymethylmethacrylate (PMMA) particles released a 92- and 72-kDa gelatinase in a dose- and time-dependent manner. Western immunoblotting confirmed that the 92- and 72-kDa gelatinolytic activities corresponded to matrix metalloproteinase-9 and matrix metalloproteinase-2 (MMP-9, MMP-2), respectively. Western immunoblotting also indicated that titanium alloy and PMMA particles increased the release of MMP-1. Northern blotting showed elevated mRNA signal levels for MMP-1, MMP-2, and MMP-9 after exposure to both types of particle. Collagenolytic activity also increased in the macrophage culture medium in response to both types of particle. Our findings support the hypothesis that macrophages release MMPs in proportion to the amount of particulate debris within periprosthetic tissues.
