Early Stage Avascular Necrosis Research Articles

A Rabbit Model of Hormone-induced Early Avascular Necrosis of the Femoral Head

Objective To establish an experimental model of early stage avascular necrosis of the femoral head (ANFH) caused by corticosteroid in adult rabbits and to observe the pathological changes with various imaging techniques. Methods ANFH was induced by a combination of hypersensitivity vasculitis caused by injection of horse serum and subsequent administration of a high dose of corticosteroid. The pathological changes were detected with digital radiography (DR), computed tomography (CT), magnetic resonance imaging (MRI), ink artery infusion angiography, hematoxylin–eosin staining, and immunohistochemistry. Results The imageological and pathological changes corresponded to the clinical characteristics of early stage ANFH. DR showed bilaterally increased bone density, an unclear epiphyseal line, and blurred texture of cancellous bone. CT showed spot-like low-density imaging of cancellous bone, thinner cortical bone, osteoporosis, and an unclear epiphyseal line. MRI showed bone marrow edema and spot-like high signals in T2-weighted imaging in cancellous bone. Ink artery infusion angiography showed fewer obstructed blood vessels in the femoral head. HE staining of pathological sections showed fewer trabeculae and thin bone, an increased proportion of empty osteocyte lacunae, decreased hematopoiesis, thrombosis, and fat cell hypertrophy. Immunohistochemistry showed attenuated expression of vascular endothelial growth factor in osteoblasts and chondrocytes, and on the inner membrane of blood vessels. Conclusion Experimental rabbit model of early stage ANFH caused by corticosteroid can be successfully established and provide the foundation for developing effective methods to treat early stage ANFH.

Course of Avascular Necrosis of Femoral Head Without Collapse of Femoral Head at First Examination: Minimum 8-Year Follow-up

Disruption of the femoral head contour by collapse of necrotic segments is considered to be an important turning point in the history of avascular necrosis of the femoral head, and in many cases, surgical treatment is required soon after the onset of symptoms. However, in a few cases, conservative treatment is sufficiently effective to avoid surgical procedures for long periods. For patients with early-stage avascular necrosis, it is important to accurately predict its natural course. This article documents the characteristics of patients who can be treated without surgery for long periods. Seventeen hips in 13 patients with avascular necrosis of the femoral head without collapse of the femoral head at first examination were followed for at least 8 years of conservative treatment. Long-term outcomes of hips with avascular necrosis were divided into 3 groups: (1) hips without collapse, (2) hips with progression but cessation of collapse, and (3) hips with progression of collapse. In groups 1 and 2, good clinical results are expected. Hips with femoral head collapse .3 mm at 3 years from the onset of hip pain progressed to osteoarthritis. Our analysis indicated that collapse of the femoral head does not necessarily indicate a poor prognosis, and even after collapse occurs, subsequent cessation of collapse can be expected in a certain percentage of hips.

Treatment of avascular necrosis of the femoral head by hepatocyte growth factor-transgenic bone marrow stromal stem cells

The treatment of hormone-induced early-stage avascular necrosis of the femoral head (ANFH) with transplantation of hepatocyte growth factor (HGF)-transgenic bone marrow stromal stem cells (BMSCs) was examined. A rabbit model of hormone-induced early ANFH was first established. BMSCs were transplanted by core decompression under the guidance of computed tomography (CT). A supportive fibrinogen drug delivery mixture (FG) was tested for mechanical enhancement of stem cell delivery. Therapeutic efficacy was evaluated by CT, magnetic resonance imaging (MRI), CT perfusion imaging, ink artery infusion angiography, hematoxylin-and-eosin staining and immunohistochemical staining for extracellular signal-regulated kinase-1/2 of pathological sections. A regular arrangement of trabeculae and obvious bone regeneration were observed in the animals receiving transplanted transgenic BMSCs with FG. Newly generated capillaries were visible on the bone plates of the trabeculae, and the bone marrow was rich in hematopoietic tissue. These results demonstrate that the combination of core decompression and transplantation of HGF transgenic autologous BMSCs enhanced blood vessel regeneration and bone reconstruction in the ANFH model. This study provides experimental data that motivate possible clinical use of this therapeutic strategy.

MRI findings in renal transplant recipients with hip and knee pain

Purpose To evaluate and demonstrate the MRI findings of renal transplant recipients with hip and knee pain and to investigate the most common etiology of pain. Materials and methods 69 hip MRIs of 57 patients with hip pain and 30 knee MRIs of 24 patients with knee pain with no history of trauma were retrospectively evaluated by two radiologists. Results In the evaluation of hip MRIs, 24 patients had avascular necrosis and effusion, 2 patients had bone marrow edema consistent with early stage of avascular necrosis. 18 patients had only intraarticular effusion, 6 patients had tendinitis, 6 patients had bursitis and 1 patient had soft tissue abscess. Five patients had muscle edema and five patients had muscle atrophy as additional findings to the primary pathologies. Among patients with knee pain, nine patients had degenerative joint disease. Seven patients had chondromalacia, five had bone marrow edema, six had meniscal tear, six had ligament rupture and two had bone infarct. Three of the patients had muscle edema accompanying to other pathologies. Conclusion The most common etiology of hip pain in renal transplant recipients is avascular necrosis as expected, intraarticular effusion is found to be the second reason for pain. However, knee pain is explained by ligament pathology, meniscal tear, chondromalacia or degenerative joint disease rather than osteonecrosis.

Arthroplasty of the shoulder

Although the first shoulder arthroplasty was implanted in 1893 by the French surgeon Jules-Emile Pean,[1][1] the development of the procedure came in the 1950s when Neer[2][2] described the results using a vitallium prosthesis to treat comminuted fractures of the head of the humerus. About 20

Arthroscopically assisted core decompression of the proximal humerus for avascular necrosis

Abstract Core decompression has been described as an effective treatment for early stage avascular necrosis of the humeral head. This article describes the technique for arthroscopically assisted core decompression of the humeral head using a transtibial anterior cruciate ligament guide. This technique provides an advantage over the open procedure by avoiding soft-tissue stripping or damaging the biceps tendon or ascending branch of the anterior humeral circumflex artery, as well as providing accurate and safe placement of the core biopsy tract and the ability to address other intra-articular pathology.

Magnetic resonance imaging criteria of successful core decompression in avascular necrosis of the hip.

To identify imaging criteria that determine the outcome of core decompression (CD) in femoral-head avascular necrosis (AVN). Radiographs and magnetic resonance imaging (MRI) of 65 hips with early stage AVN treated by core decompression between January 1990 and December 2000 for AVN were reviewed. All hips were categorized into two groups according to the result of CD using total hip arthroplasty (THA) as an end point. Hips that had no THA at follow-up were allocated to group I; those treated with a THA were allocated to group II. CD results were calculated for each group using THA as an end point. The parameters analyzed were the presence or absence of edema associated with the double-line sign on the preoperative MRI, the type of epiphyseal scar (ES) according to Jing, and the type of necrosis according to Mitchell. On follow-up, 45 hips had no THA (group I); 20 patients had a THA (group II). Patients with a radiographic crescent sign and those with edema associated with the double-line sign progressed to THA significantly more frequently. The extent of the necrosis had less discriminatory effect between the two groups. ES and necrotic tissue types had no prognostic value. In regard to the success of CD, it is important to differentiate on MRI between a double line sign plus bone marrow edema and a double-line sign only.

Cost-Effectivess of Core Decompression for the Treatment of Early Stage Avascular Necrosis of the Femoral Head

Cost-Effectivess of Core Decompression for the Treatment of Early Stage Avascular Necrosis of the Femoral Head

Prognosis of Early Stage Avascular Necrosis of the Femoral Head

Seventy-two femoral heads in 63 patients in whom avascular necrosis of the femoral head was in the early stage were followed up prospectively for a mean period of 6 years 1 month. All of the necrotic lesions were confirmed by magnetic resonance imaging. At the time of final outcome, 46 (64%) of the 72 hips were symptomatic. Necrotic lesions greater than 2/3 of the weightbearing portion on T1 weighted central coronal images indicated a high risk of clinical deterioration. Fifty-nine of the 72 hips initially had necrotic lesions greater than 2/3 of the weightbearing portion, and 44 (75%) of these 59 hips were symptomatic at the final outcome. However, in the radiographic assessment of 15 (25%) asymptomatic hips, even when the necrotic lesions were greater than 2/3 of the weightbearing portion as shown by magnetic resonance imaging, the continuous absence of any radiographic abnormality indicated the possibility of a continuous asymptomatic stage for at least several years.

Early-stage avascular necrosis of the femoral head: MR imaging for prognosis in 31 cases with at least 2 years of follow-up.

Thirty-one cases of stage 1 or 2 osteonecrosis (ON) of the hip in 27 patients were studied with T1-weighted coronal magnetic resonance (MR) imaging. Three quantitative parameters were measured on the contiguous MR sections, corresponding to the 2-cm-wide median portion of the femoral head: the angle filled by ON (alpha), the percentage of weight-bearing femoral cortex involved with ON (WB), and the percentage of femoral head surface involved with ON. The clinical and radiologic courses were assessed after at least 2 years of follow-up (mean, 46 months). Core decompression was performed in 12 cases of ON. Values were strikingly lower in the group with good clinical or radiologic outcome versus poor outcome, with very little overlapping. WB was the more reliable parameter. Outcome of hips treated with versus without core decompression appeared closely related with these MR parameters and not with the treatment procedure. Thus, a quantitative approach to determination of extent and location of the lesion on the initial MR image appears accurate for use in the prediction of long-term outcome of ON. Effectiveness of core decompression should be reevaluated on this basis.

Bone marrow edema of the hip: MR findings after core decompression.

Magnetic resonance imaging is an extremely sensitive technique for evaluation of bone marrow changes at an early stage of avascular necrosis (AVN) of the hip. We therefore examined 11 painful hips whose clinical symptoms led us to suspect idiopathic AVN. The radiographs of all of these either were normal or demonstrated a minimal decrease in radiodensity. Magnetic resonance demonstrated diffuse signal loss of the bone marrow at short TR/TE images of the femoral head in all hips, with various extensions in the head, neck, and intertrochanteric area. These regions turned iso- to hyperintense on long TR/TE images compatible with bone marrow edema (BME). Focal abnormalities characteristic for AVN were not seen in any of the cases. Radionuclide studies performed in six cases were positive. All patients underwent core decompression treatment. Hydrostatic bone marrow pressure measurement and intraosseous venography were positive in five cases when measured. Histology available in eight cases confirmed the presence of BME. Furthermore, the bone changes corresponded to those of early AVN. Follow-up examinations after core decompression with MR showed normal signal intensity in all cases. Magnetic resonance represents a viable diagnostic tool for BME and can monitor the therapeutic success of core decompression. Whether BME of the femoral head constitutes a distinct transient syndrome or represents an early form of AVN is controversial at present. Our findings support those who believe that BME may represent an initial stage of idiopathic AVN.