股骨头缺血性坏死病程发展及治疗中的生物力学因素

在股骨头缺血性坏死病程发展及治疗中,生物力学因素起着重要的作用。通过生物力学因素的研究,可以对股骨头是否会塌陷及各种预防塌陷的治疗方法进行客观评测,从而有助于临床的治疗。     

经股骨颈股骨头成形术治疗塌陷期股骨头缺血性坏死的实验研究

[目的]本实验旨在评价经股骨颈股骨头成形术治疗塌陷期股骨头缺血性坏死的效果。[方法]取10只塌陷期股骨头缺血性坏死犬，行经股骨颈股骨头成形术，测定其生物力学性能并与健侧对比，以及测定其手术前后的X线片并进行对比。[结果]经股骨颈股骨头成形术能满意的撑起塌陷软骨和恢复股骨头生物力学性能。[结论]经股骨颈股骨头成形术可成为治疗塌陷期股骨头缺血性坏死的理想方法，但长期疗效尚待验证。     

生物力学研究在股骨头缺血性坏死显微外科治疗中的应用

股骨头缺血性坏死(INFH)过程中生物力学因素的影响已越来越引起人们的重视。1 985年Ueo等[1 ] 发现股骨头缺血性坏死区与其血流分布并不相符,即血供好的区域也可能出现坏死,所以他们推测生物力学因素可能在股骨头缺血性坏死病程中起着至关重要的作用。放射学诊断明确的INFH患者并非都发生塌陷,有些病人的囊变区会逐渐消失,而有些病人的囊变则可导致股骨头塌陷,前者囊变一般位于软骨下骨较远的区域或者范围较小,后者则多位于软骨下区或范围较大,这又从另一个侧面揭示了生物力学因素对于INFH的影响。股骨头缺血性坏死如果发生软骨面塌陷…     

生物力学研究在股骨头缺血性坏死显微外科治疗中的应用

股骨头缺血性坏死(INFH)过程中生物力学因素的影响已越来越引起人们的重视。1985年Ueo等发现股骨头缺血性坏死区与其血流分布并不相符，即血供好的区域也可能出现坏死，所以他们推测生物力学因素可能在股骨头缺血性坏死病程中起着至关重要的作用。放射学诊断明确的INFH患者并非都发生塌陷，有些病人的囊变区会逐渐消失．而有     

股骨头缺血性坏死（avascular necrosis of the femoral head，ANFH）

股骨头缺血性坏死也称股骨头无菌性坏死，是由于多种原因导致的股骨头局部血运障碍导致骨细胞、骨髓造血细胞和脂肪细胞死亡的病理过程，从而引起骨小梁断裂、股骨头塌陷的一种病变。股骨头坏死的病因复杂多样，难以全面系统地分类，大体上可分为创伤性及非创伤性两大类。导致创伤性股骨头缺血性坏死的疾病主要为股骨颈骨折、髋关节脱位、髋臼骨折等；导致非创伤性股骨头缺血坏死的疾病主要为某些血液系统疾病、脂肪代澍紊乱、酒精中毒、肾上腺皮质功能亢进或。肾上腺糖皮质激素服用或注射过量等。当然，股骨头本身解剖特点，特别是血液循环方面的特点，以及髋关节生物力学方面的特征，也是股骨头病变较易发生而引起缺血性坏死的内在因素。总的来讲，股骨头缺血性坏死的发病机制可能是血流动力学、代湔生化和生物力学等多种因素改变并彼此影响的结果。     

股骨头坏死动物模型研究进展

各种股骨头坏死治疗新方法的发展基于能够模拟人股骨头坏死自然病程的动物模型.通过外科手术或化学药物使动物股骨头坏死并不困难,但建立一种与人股骨头坏死发展相似的、能够逐步进展至晚期关节面塌陷的动物模型却十分困难.目前报道的各种四足动物模型均无法模拟人股骨头坏死逐步进展至晚期的关节面塌陷.两足大型动物鸸鹋股骨头坏死模型的成功使生物力学因素在股骨头坏死过程中的作用受到重视.该文就不同动物模型的特点、优缺点及其主要的建模方法作一综述.     

早期无症状股骨头坏死是否应该外科干预治疗

目前对于塌陷前股骨头缺血性坏死的治疗尚无统一的治疗方法,特别是无症状股骨头坏死。但普遍认为如果临床确诊股骨头缺血性坏死而不采取治疗,有70%~80%的病例病情将进展出现头塌陷。但是对于早期无症状股骨头坏死是否采取手术早期干预治疗仍有争议。目前随着MRI的普及以及MRI对     

早期年轻股骨头坏死保髋治疗常用方法及效果

正股骨头坏死(osteonecrosis of the femoral head,ONFH)又称缺血性坏死(avascular necrosis,AVN),是造成青壮年髋关节残疾的最常见原因之一。病因并不明。由于生物力学作用可能引起股骨头塌陷,因而难以治疗。在股骨头塌陷的前期采用非关节置换手术治疗,对于保护关节及延缓病理进程非常重要[1-2]。寻找安全、有效、微创的方法一直是骨科研究的重要课题。保髋治疗的目的是缓解疼痛、重建髋关节功能,避免或     

带蒂大网膜移植术治疗成人股骨头缺血性坏死的疗效观察

目的探讨一种治疗成人股骨头缺血性坏死的新方法。方法于股骨颈前上方开槽进入股骨头病灶处,彻底清除死骨及硬化囊壁,将大网膜植入治疗股骨头坏死53例。结果50例疼痛消失,3例明显减轻。X线片示股骨头塌陷停止发展。按新的疗效评价标准,优42例,良6例,可3例,差2例,优良率为90．6%。结论本术式能够重建股骨头的血液循环,恢复其活力,降低股骨头内压,从而防止后期股骨头负重区塌陷。该方法适用于中青年股骨头缺血性坏死Ⅱ_b、Ⅲ、Ⅳ早期患者,是一种较理想的治疗方法。     

非创伤性成人股骨头缺血性坏死股骨头塌陷的预测

股骨头缺血性坏死特别是非创伤性股骨头缺血性坏死高发于中青年[1] ,发病机理尚不十分清楚 ,尽管导致股骨头缺血性坏死的原因不同 ,但却有相似的病理过程和结果 ,多数患者在出现症状后如不经治疗 ,将不可避免地出现股骨头塌陷[1] 。股骨头塌陷是导致髋关节骨性关节炎和关节功能受损的重要原因。患者因此常需接受全髋关节置换治疗。由于多数患者年青且累及双侧髋关节等因素 ,人工关节置换术后远期疗效较其他疾病差[1] 。本病具有很高的塌陷率 ,但目前对股骨头缺血性坏死自然病程尚不十分清楚[1,2 ] 。通常所认为的股骨头塌陷的发生率为 6 8%…     

The natural history of asymptomatic osteonecrosis of the femoral head in adults with sickle cell disease

BACKGROUND: Osteonecrosis of the femoral head is a frequent complication in adult patients with sickle cell disease. However, little is known about the natural history of asymptomatic lesions. METHODS: One hundred and twenty-one patients (121 hips) with sickle cell disease and asymptomatic osteonecrosis of the femoral head that was contralateral to a hip with symptomatic osteonecrosis were identified with magnetic resonance imaging between 1985 and 1995. The lesions were graded with use of the Steinberg classification system. The patients were followed with annual plain radiographs. The mean duration of follow-up was fourteen years. RESULTS: At the time of the initial evaluation, fifty-six hips were classified as Steinberg stage 0, forty-two hips were classified as Steinberg stage I, and twenty-three hips were classified as Steinberg stage II. At the time of the most recent follow-up, pain had developed in 110 previously asymptomatic hips (91%) and collapse had occurred in ninety-three hips (77%). Symptoms always preceded collapse. Of the fifty-six hips that were classified as Steinberg stage 0 at the time of the initial evaluation, forty-seven (84%) had symptomatic osteonecrosis and thirty-four (61%) had collapse at the time of the most recent follow-up. Of the forty-two asymptomatic stage-I hips, forty (95%) became symptomatic within three years and thirty-six (86%) had collapse of the femoral head. Of the twenty-three asymptomatic stage-II hips, all became symptomatic within two years and all collapsed; the mean interval between the onset of pain and collapse was eleven months. At the time of the final follow-up, ninety-one hips (75%) had intractable pain and required surgery. CONCLUSIONS: Untreated asymptomatic osteonecrosis of the femoral head in patients with sickle cell disease has a high likelihood of progression to pain and collapse. Because of the high prevalence of complications after total hip arthroplasty in patients with this disease, consideration should be given to early surgical intervention with other procedures in an attempt to retard progression of the disease.     

Influence of acetabular coverage on hip survival after free vascularized fibular grafting for femoral head osteonecrosis

BACKGROUND: Osteonecrosis of the femoral head frequently results in collapse of the head and subsequent arthrosis of the joint. Surgical treatment has been based entirely on the evaluation of the femoral side of the hip joint, with little consideration given to the possible influence on outcome of the orientation of the acetabulum. METHODS: We retrospectively reviewed a consecutive series of 200 hips in 160 patients with osteonecrosis of the femoral head who had undergone free vascularized fibular grafting between 1997 and 1998. The mean duration of clinical follow-up was 7.5 years. Ninety-one hips in seventy-one patients were evaluated radiographically for evidence of progression of femoral head collapse at a minimum of two years, and a mean of three years, postoperatively. We defined conversion to a total hip arthroplasty and progression of femoral head collapse as the failure end points, and we analyzed the association of the acetabular center-edge angle of Wiberg, the area and laterality of the lesion, the amount of preoperative collapse of the femoral head, and the etiology of the osteonecrosis with the likelihood of failure. RESULTS: Forty-eight (24%) of the 200 hips had undergone conversion to a total hip arthroplasty at the time of the final clinical follow-up. In addition, 15% (fourteen) of the ninety-one hips with sufficient radiographic follow-up demonstrated progression of femoral head collapse at the time of the final radiographic examination. Of the hips with a center-edge angle of 30 degrees , 10% had progressive collapse (p = 0.002) and 6% were converted to a total hip arthroplasty (p < 0.001). Neither the etiology nor the size of the lesion was significantly correlated with progression of collapse or conversion to a total hip arthroplasty. CONCLUSIONS: Patients with osteonecrosis of the femoral head and a suboptimal center-edge angle of the hip are at substantial risk for progression of femoral head collapse and conversion to a total hip arthroplasty following free vascularized fibular grafting. An estimation of the degree of hip dysplasia should be included in the preoperative assessment of patients with osteonecrosis of the femoral head for prognostic and possibly surgical planning purposes.     

Bone remodeling of a femoral head after transtrochanteric rotational osteotomy for osteonecrosis associated with slipped capital femoral epiphysis: a case report

A rare case of a 12-year-old boy on whom a joint-preserving operation for osteonecrosis after slipped capital femoral epiphysis (SCFE) was performed, is described. Firstly, in situ pinning was performed for acute-on-chronic SCFE. However, osteonecrosis and collapse of the femoral head occurred at 7 months after surgery. Secondly, transtrochanteric rotational osteotomy (TRO) was performed against progression of the collapse of the femoral head. Eight years of X-ray observation revealed bone remodeling at the osteonecrotic region. No documentation has been reported about the potential of bone remodeling of a femoral head with osteonecrosis after SCFE. This case indicates that a joint-preserving operation such as TRO is capable of promoting bone remodeling in such circumstances.     

Articular cartilage degeneration in post-collapse osteonecrosis of the femoral head. Radiographic staging, macroscopic grading, and histologic changes

BACKGROUND: Osteonecrosis of the femoral head is a debilitating condition characterized by progressive degeneration of bone that eventually leads to collapse of the femoral head in the majority of patients. Femoral head-sparing procedures have been more successful in pre-collapse stages of osteonecrosis than in post-collapse stages, although some patients with early post-collapse disease have had no additional progression of the disorder. Nevertheless, the effects of collapse on the articular cartilage are not well understood, and radiographic staging of femoral head collapse does not address the condition of the articular cartilage. METHODS: In the current study, we investigated the relationship between the mechanical properties of post-collapse articular cartilage and the histologic findings and macroscopic grades of the articular cartilage from hips with stage-IV osteonecrosis, those with stage-V osteonecrosis, and those without osteonecrosis. RESULTS: The cartilage from both stage-IV and stage-V hips showed significant degeneration compared with the normal control cartilage, but there was no significant difference between the two stages. There was significant variability in the histologic and mechanical properties of these samples that correlated strongly with the gross appearance of the cartilage surface but not with the lesion size. CONCLUSIONS: These results suggest that articular cartilage that appears macroscopically normal may remain mechanically functional even in patients with large osteonecrotic lesions or a late radiographic stage of the disease.     

Current management options for osteonecrosis of the femoral head: part II, operative management

Osteonecrosis of the femoral head is a multifactorial disease that can result in significant clinical morbidity and affects patients of any age, including young and active patients. Late sequelae of femoral head osteonecrosis include femoral head collapse and subsequent degeneration of the hip joint. A high index of suspicion and improved radiographic evaluation allow orthopedic surgeons to identify this disease at an earlier stage. Current management options for hip osteonecrosis have results that vary according to patient population and disease stage. Modifications of older techniques, as well as emerging technologies, have led to the development of management strategies that may be able to alter the course of femoral head osteonecrosis.     

Current management options for osteonecrosis of the femoral head: part 1, diagnosis and nonoperative management

Osteonecrosis of the femoral head is a multifactorial disease that can result in significant clinical morbidity and affects patients of any age, including young and active patients. Late sequelae of femoral head osteonecrosis include femoral head collapse and subsequent degeneration of the hip joint. A high index of suspicion and improved radiographic evaluation allow orthopedic surgeons to identify this disease at an earlier stage. Current management options for hip osteonecrosis have results that vary according to patient population and disease stage. Modifications of older techniques, as well as emerging technologies, have led to the development of management strategies that may be able to alter the course of femoral head osteonecrosis.     

Asymptomatic osteonecrosis: should it be treated?

Currently, there is no consensus regarding the treatment of precollapse osteonecrosis, particularly for asymptomatic osteonecrosis. With approximately 10,000 to 20,000 new cases of osteonecrosis a year, no single surgeon or center has the kind of experience that is able to address the most important questions concerning this disease. The literature strongly documents that symptoms of osteonecrosis will progress. Although the literature also supports the progression of asymptomatic osteonecrosis to symptomatic osteonecrosis on to collapse, that support is less convincing. Progression is proportional to lesion size, with small lesions (< 15% of femoral head involvement by volume) unlikely to progress. Although the results of core decompression have been somewhat controversial, the weight of the literature supports both the efficacy and safety of the procedure. The decision to treat osteonecrosis with core decompression is primarily based upon lesion size and stage of disease and does not necessarily depend on whether the patient is symptomatic. As large lesions (> 30% of the femoral head) are less likely to be successfully treated by core decompression and small lesions (< 15% of the femoral head) are less likely to progress, asymptomatic lesions within these ranges can be observed. The literature supports the position that moderately sized lesions (15-30% of the femoral head) should be treated by core decompression (with or without bone grafting).     

Multimodal imaging quantitation of the lesion size in osteonecrosis of the femoral head

Early diagnosis of osteonecrosis of the femoral head is important for initiating early treatment, which is associated with a more favorable outcome for patients. Confusion in evaluating the severity of the disease, and the clinical outcome after treatment partially is attributed to the use of various staging systems that are based on qualitative rather than quantitative criteria. At the authors' institution, 45 patients (77 hips) with osteonecrosis of the femoral head were evaluated using a multimodal imaging approach that included conventional radiography, bone scintigraphy, and magnetic resonance imaging. A computerized image analysis program that allowed quantification of the lesion size on radiographs and magnetic resonance images was used. Measurements of the extent of involvement on radiographs and selected serial magnetic resonance images were compared in 33 hips (42.9%) before collapse versus 44 hips (57.1%) after collapse. The size of the necrotic lesion varied significantly according to the specific stage of disease. Quantification of the lesion during the course of the disease provided a record of the progression of osteonecrosis, despite a spurious stability in staging. In general, conventional radiography closely approximated measurements of the lesion size obtained by magnetic resonance imaging. Bone scintigraphy and magnetic resonance imaging were well suited for detection of osteonecrosis at an early stage. Finally, precise quantification of the lesion size was an optimal preoperative means for evaluating the extent of involvement of the femoral head in the early and advanced stages of osteonecrosis.     

Treatment of osteonecrosis of the femoral head with implantation of autologous bone-marrow cells. A pilot study

BACKGROUND: Aseptic nontraumatic osteonecrosis of the femoral head is a disorder that can lead to femoral head collapse and the need for total hip replacement. Since osteonecrosis may be a disease of mesenchymal cells or bone cells, the possibility has been raised that bone marrow containing osteogenic precursors implanted into a necrotic lesion of the femoral head may be of benefit in the treatment of this condition. For this reason, we studied the implantation of autologous bone-marrow mononuclear cells in a necrotic lesion of the femoral head to determine the effect on the clinical symptoms and the stage and volume of osteonecrosis. METHODS: We studied thirteen patients (eighteen hips) with stage-I or II osteonecrosis of the femoral head, according to the system of the Association Research Circulation Osseous. The hips were allocated to a program of either core decompression (the control group) or core decompression and implantation of autologous bone-marrow mononuclear cells (the bone-marrow-graft group). Both patients and assessors were blind with respect to treatment-group assignment. The primary outcomes studied were safety, clinical symptoms, and disease progression. RESULTS: After twenty-four months, there was a significant reduction in pain (p = 0.021) and in joint symptoms measured with the Lequesne index (p = 0.001) and the WOMAC index (p = 0.013) within the bone-marrow-graft group. At twenty-four months, five of the eight hips in the control group had deteriorated to stage III, whereas only one of the ten hips in the bone-marrow-graft group had progressed to this stage. Survival analysis showed a significant difference in the time to collapse between the two groups (p = 0.016). Implantation of bone-marrow mononuclear cells was associated with only minor side effects. CONCLUSIONS: Implantation of autologous bone-marrow mononuclear cells appears to be a safe and effective treatment for early stages of osteonecrosis of the femoral head. Although the findings of this study are promising, their interpretation is limited because of the small number of patients and the short duration of follow-up. Further study is needed to confirm the results.