The role of hip arthroscopy in the evaluation of avascular necrosis

This prospective study evaluated the correlation between plain radiographs, magnetic resonance imaging (MRI), and diagnostic arthroscopy in the staging of avascular necrosis of the femoral head. Fifty-two hips in 46 patients were prospectively staged using radiographic and MRI staging systems. Patients subsequently underwent hip arthroscopy to visualize the articular surface prior to considering salvage of the femoral head and debride delaminated osteochondral fragments. Weighted Kappa analysis revealed only moderate correlation between MRI and plain radiographs (K=.11), MRI and arthroscopy (K=.21), and plain radiographs and arthroscopy (K=.19). Six (46%) of 13 patients with a radiographically apparent subchondral fracture demonstrated collapse of the articular surface at arthroscopy. Four (24%) of 17 hips with >2 mm of collapse of the femoral head on plain radiographs demonstrated fragmentation of the osteochondral surface of the femoral head at arthroscopy. In 5 patients with flattening of the femoral head, 3 patients had delamination of both the femoral and acetabular surfaces. In regard to labral pathology, 5 of 22 post-collapse hips also had large bucket handle tears of the labrum. Arthroscopy of the hip revealed osteochondral degeneration that was not detected by plain radiographs or MRI in 36% of post-collapse femoral heads.     

The fate of nontraumatic avascular necrosis of the femoral head. A radiologic classification to formulate prognosis.

One hundred fifteen hips in 87 patients with non-traumatic avascular necrosis of the femoral head (ANFH) (men, 54; women, 33) (steroid induced, 49; alcoholic, 21; idiopathic, 17) were radiologically classified into six distinct types (Types 1A, 1B, 1C, 2, 3A, and 3B) based on the following: (1) the size and location of the necrotic area in relation to the weight-bearing surface of the acetabulum as seen on anteroposterior views in the standing position and (2) initial roentgenographic abnormalities. The natural course of the disorder in each group were observed for more than two years (range, two to 18 years; mean, five years). Of the 79 hips without collapse of the femoral heads (Stage II) at the beginning of follow-up evaluation, 42 femoral heads subsequently collapsed. These collapses took place predominantly in cases involving Types 1C, 2, and 3B. Conversely, the incidence of collapse was significantly low in the other groups (Types 1A, 1B, and 3A). Collapse of the femoral head occurred in 78 femoral heads of 115. The incidences of collapse by group was 0% for Type 1A, 19% for Type 1B, 94% for Type 1C, 100% for Type 2, 12% for Type 3A, and 100% for Type 3B. These data indicate that this radiologic classification of necrosed femoral heads is useful for evaluation of the risk of collapse or for prognosis of the affected hip joints as well as for choosing an appropriate treatment modality, either conservative or surgical, during the early stages of ANFH.     

Articular collapse and surgical frequency in corticosteroid-associated osteonecrosis of the femoral head and the knee: an MRI-based prospective study

Background

The purpose of this magnetic resonance imaging (MRI)-based prospective study was to clarify the frequency of articular collapse in, and to define the frequency with which surgical interventions are performed for, osteonecrosis of the femoral head and the knee.

Methods

MRI screening for osteonecrosis of the femoral head and the knee was prospectively performed within 1 year after corticosteroid administration. Those patients with osteonecrosis were conservatively followed with MRI to detect articular collapse by bone marrow edema. Several surgical interventions were considered after articular collapse. The frequencies of collapse and of surgical intervention were compared using the Kaplan–Meier method and the log-rank test.

Results

Of 1,239 joints (623 hips and 616 knees) surveyed in the study, osteonecrosis was identified in 370 (191 hips and 179 knees) by MRI. Thus, the incidence of osteonecrosis was 30 % (31 % in hip and 29 % in knee). Of 155 hips and 154 knees followed for more than 2 years, the frequency of articular collapse was significantly higher in osteonecrosis of the femoral head than in osteonecrosis of the knee (p?<?0.05, 38 % [59 hips] versus 5 % [7 knees]). After articular collapse, surgery was performed significantly more often for osteonecrosis of the femoral head than for osteonecrosis of the knee (p?=?0.024, 63 % [37 femoral heads] versus 29 % [2 knees]).

Conclusions

Osteonecrosis of the femoral head can result in clinically more severe sequelae than osteonecrosis of the knee, and surgery is more often performed for osteonecrosis of the femoral head.     

Magnetic resonance imaging in the early diagnosis of ischemic necrosis of the femoral head. Preliminary results

Magnetic resonance imaging (MRI) was performed on the hips of 25 patients with suspected ischemic necrosis of the femoral head. Twenty-six femoral heads manifested MRI changes of ischemic necrosis: diminished bone marrow signal in a ringlike, focal, or diffuse pattern. Plain radiographs were normal in 13 of 26 MRI-positive hips; six were asymptomatic. MRI was more effective in detecting early cases than conventional 99mTc-diphosphonate or 99mTc-sulfur colloid (SC) bone scanning. There were no false-negative MRI examinations, but diphosphonate scans were negative in nine hips with normal radiography and abnormal MRI. Sulfur colloid scans were normal in only two hips with positive MRI, but SC scan results were often equivocal because isotope deficits were bilaterally symmetric. The results of this preliminary investigation imply that MRI has extraordinary sensitivity for the detection of early ischemic necrosis. Unlike radionuclide scanning, MRI shows the exact location and extent of femoral head necrosis. Because MRI is expensive, it should be used in a cost-effective manner. Therefore, MRI is best suited for the diagnosis of early cases where less expensive tests are negative or equivocal and as a precursor to more costly interventional procedures, such as core biopsy study or decompression.     

The use of alendronate to prevent early collapse of the femoral head in patients with nontraumatic osteonecrosis. A randomized clinical study

BACKGROUND: Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis. METHODS: Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained. RESULTS: During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001). CONCLUSIONS: Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse. LEVEL OF EVIDENCE: Therapeutic Level I.     

Significance of lesion size and location in the prediction of collapse of osteonecrosis of the femoral head: a new three-dimensional quantification using magnetic resonance imaging.

Size and location of a necrotic lesion are considered important factors predicting collapse of the femoral head in the early stages of osteonecrosis. However, few analytical studies have performed a three-dimensional quantification of lesions to clarify how these two morphological factors are related to the occurrence of collapse. We evaluated the relevance of lesion size and location for prediction of collapse quantitatively using new three-dimensional indexes. Magnetic resonance (MR) imaging was performed in 65 hips in a consecutive series of 47 patients with osteonecrosis without radiological evidence of collapse. Lesion volume as well as latitude and longitude of the center of gravity of the lesion within the femoral head were calculated. Thirty-three hips developed radiological collapse, while in the remaining 32 hips collapse did not occur over 2 years. Multiple logistic regression analysis showed a significant relationship between lesion volume and radiological collapse. In 35 hips in which the lesion volume was less than 30% of the femoral head, only 9 collapsed. In comparison with non-collapsed hips, collapsed hips had a significantly higher combined value for latitude and longitude of the lesion, corresponding to the anterosuperior portion of the femoral head. Quantitative analysis of lesion morphology demonstrated that lesion volume is strongly correlated with risk of collapse, and that lesion location is an important prognostic indicator of collapse in small necrotic lesions.     

股骨头缺血坏死MRI表现分析

目的观察系列MRI上股骨头坏死的坏死信号和面积比例变化。方法根据股骨头坏死的诊断标准,对10例(20髋)具有2次及以上MRI成像的股骨头坏死患者进行研究,其中男8例,女2例;年龄24~58岁,平均40岁。两次MRI成像平均相差18.1个月,观察其坏死信号和面积比例变化。结果第1次MRI检查时的平均坏死面积比例为52.62%±17.90%,第2次MRI检查时的平均坏死面积比例52.24%±19.39%,两者差异无显著性(P=0.687)。两次MRI检查时,均有180个层面,共有38个层面出现信号改变。在无外科治疗及塌陷出现的8髋65个层面中,2个层面发生信号改变;在塌陷加重而无外科治疗的3髋37个层面中,3个层面发生信号改变;在出现塌陷或有外科治疗的9髋78个层面中,33个层面发生信号改变,(P=0)。结论股骨头坏死的坏死面积比例不随病程的延长及临床分期的进展而改变。如无外科干预或软骨下骨折出现,股骨头坏死的信号强度也无明显变化。     

Natural history of avascular necrosis of the femoral head in systemic lupus erythematosus

Clinical and radiographic studies were performed on 228 hips of 145 patients with avascular necrosis of the femoral head (ANFH). The patients were divided into three groups: group A consisted of 33 patients with systemic lupus erythematosus (SLE) who had been treated with systemic corticosteroids (59 hips); group B consisted of 41 patients with a history of corticosteroid treatment, excluding patients with SLE (69 hips); and group C consisted of 71 patients with no history of corticosteroid use (100 hips). Of the 228 hips, 80 hips at an early stage of the necrosis, but not showing collapse, were selected and classified by the criteria of the Japanese Investigation Committee (JIC) to define the natural history of the disease. In the SLE patients (group A), there was a predisposition to bilateral involvement and multiple sites of bone necrosis. Eighty percent of the femoral heads followed at an early stage had collapsed at the end of the follow-up, the incidence of collapse in group A being higher than that in the other groups. The collapses in group A were predominantly types 1C, 2, and 3B according to the JIC criteria. The incidence of collapse was significantly lower in type 1A and type 3A than in the other types. The classification proposed by the JIC, in terms of types with regard to size and location of the necrotic area on antero-posterior radiographs, was very useful for evaluation of the risk of collapse as well as for selecting appropriate treatment modalities, either conservative or surgical, during the early stages of ANFH.     

Osteonecrosis of the femoral head associated with pregnancy

A 31-year-old pregnant woman suddenly complained of bilateral hip pain 2 weeks before delivery. She was delivered of triplets by Caesarean section. She had been treated with human menopausal gonadotropin and human chorionic gonadotropin (hMG-hCG) before pregnancy. Radiograms of the hip joint showed collapse of the femoral heads bilaterally. Magnetic resonance imaging revealed a band pattern of low signal intensity for both hips on T1- and T2-weighted images. She had no history of steroid therapy or alcohol abuse. Osteonecrosis of the femoral heads bilaterally associated with pregnancy was confirmed. Pathology of the femoral head showed typical empty lacunae and necrosis of the trabecula. Received: 8 July 1997     

股骨头坏死表面积测量及在股骨头塌陷预测中的应用

目的探讨采用磁共振扫描(magneticresonanceimaging,MRI)的图像,计算股骨头坏死(osteonecrosisofthefemoralhead,ONFH)表面积及坏死面积占整个股骨头表面积的百分比(简称坏死表面积比),检验其准确性,并应用于临床预测股骨头塌陷。方法2001年6月~2003年6月,对8例13髋拟行关节置换的ONFH患者术前作标准的MRI扫描,依T1连续图像计算,得出坏死表面积及坏死表面积比。将手术标本锯成与MRI扫描相同的层厚和层数,应用坐标纸粘贴,图像分析仪测出数据,并作统计学分析。另对16例25髋、期非手术治疗的ONFH患者,用MRI扫描图像法测定其股骨头坏死表面积及坏死表面积比,临床随访至股骨头出现塌陷,未塌陷者至少随访24个月,比较两者差异。结果MRI图像法与标本测量的数据差异无统计学意义(P>0.05)。随访的16例25髋中,17髋发生股骨头塌陷,坏死表面积为31.06±8.10cm2(95%CI26.58~35.55),坏死表面积比为58.91%±15.11%(95%CI51.14~66.68),未塌陷的8髋坏死表面积为14.16±9.32cm2(95%CI6.37~21.95),坏死表面积比为29.48%±19.76%(95%CI12.97~45.99)。未塌陷组中仅4髋坏死表面积比>33%,塌陷组均>33%。结论MRI图像法能较准确计算股骨头坏死表面积及坏死表面积比,可用于预测股骨头塌陷,坏死表面积比>33%为股骨头塌陷的临界值。此计算法仍较复杂,宜进一步简化,以利临床应用。     

激素治疗SARS患者中期随访的髋部MRI表现

目的 对应用激素治疗的严重急性呼吸综合征(severe acute respiratory syndrome,SARS)患者进行中期髋部MRI随访,探讨早期股骨头坏死和未发生股骨头坏死即正常股骨头的MRI特征.方法 2003年6月至2004年1月对539例(1078髋)应用激素治疗的SARS患者行MR及X线榆查,诊断股骨头坏死210髋,无股骨头坏死868髋.2007年2至11月对510例(1020髋)SARS患者再行MR及X线复查.观察早期股骨头坏死和未发生股骨头坏死股骨头的MRI表现及其变化.结果 末次随访时无新发股骨头坏死病例,应用激素冲击治疗的SARS患者MRI影像上的股骨头坏死均出现在激素治疗后的6个月内.股骨头塌陷或手术后,股骨头坏死的信号类型发生改变,表现为T1加权像低信号,对应STIR序列上高信号.3髋出现坏死范围减小.正常股骨头在T1加权像上有四种MRI影像类型.24髋初次诊断无股骨头坏死者T1加权像出现异常表现,但STIR序列均无异常高信号.这些信号类型在随访的MRI上发生了改变.结论 应用激素冲击治疗的SARS患者,MRI影像上出现股骨头坏死均发生在激素治疗后的6个月内,少数早期坏死股骨头的坏死范围会减小.正常股骨头的MRI影像存在变异.T1加权像上低信号带、对应STIR序列上高信号可作为股骨头坏死的诊断标准.     

Correlation between the findings of magnetic resonance imaging and prognosis of patients with predisposing factors of aseptic necrosis of the femoral head

Eighteen patients with the predisposing factors for aseptic necrosis of the femoral head were followed up for more than two years after the initial magnetic resonance (MR) imaging. At the time of the initial examination, 24 femoral heads showed abnormal low-intensity areas on MR images without abnormal findings on plain radiographs. Among them, six femoral heads collapsed in the follow-up period. The initial mid-coronal T1-weighted MR images of these femoral heads had shown characteristic findings, that is, band-shaped low-intensity areas with the lateral end not covered by the acetabulum. Subchondral fracture of the femoral head occurred in the vicinity of the lateral end of the band. The findings of initial MR imaging seem to predict subsequent collapse of the femoral head.     

美多巴治疗早期非创伤性股骨头坏死的近期疗效观察

目的 探讨美多巴治疗早期非创伤性股骨头坏死的近期疗效.方法 2002年10月至2008年11月,31例(48髋)早期股骨头坏死患者接受口服美多巴治疗,男24例(36髋),女7例(12髋);年龄24～70岁,平均40.5岁.16例(27髋)有激素应用史,10例(13髋)有长期饮用白酒史,2例(4髋)兼有激素及长期饮用白酒史,3例(4髋)原因不明,均无明确创伤史.按Ficat方法进行分期:Ⅰ期4髋,Ⅱa期40髋,Ⅱb期4髋.患者均表现为髋关节疼痛及活动受限.美多巴治疗的初次剂量为0.25g/d,如无不良反应,则逐渐缓慢增加至每次0.25 g,每天3次或每次0.5 g,每天2次.所有患者均摄双髋前后位X线片及行MR检查.采用Charnley改良Merle d'Aubigne临床综合评分方法评估疗效.结果 所有患者均获得随访,随访时间12～84个月,平均27.8个月.18例患者已连续服药10～28个月,平均22.21个月,已完成服药疗程;另13例患者仍在服药期间.患者临床症状均改善,X线片显示股骨头骨密度增高,68.75%(33/48)的股骨头维持原有形状,MRI坏死指数降低,临床满意率91.67%(44/48),治疗成功率72.92%(35/48),股骨头塌陷率27.08%(13/48).结论 近期临床疗效表明美多巴可以阻止或推迟早期坏死的股骨头发生塌陷.     

Vascularized pedicle bone-grafting for nontraumatic avascular necrosis of the femoral head A 5- to 11-year follow-up

We investigated the results of 31 hips in 26 patients with nontraumtic (n = 20) and steroid-induced (n = 6) avascular necrosis of the femoral head (ANFH) treated with vascularized iliac pedicle bone graft (PBG). The average age at operation was 38.3 years. Three were women and 23 men. The average follow-up was 8.0 years. The Harris hip score prior to operation and at latest follow-up improved from 62 to 83; one hip collapsed and was revised with a bipolar endoprosthesis. At the final follow-up, 19 hips (63%) were clinically rated as good to excellent, 4 fair, and 7 poor. At the final follow-up, 15 of 27 hips (56%) of stage II before operation showed progressive collapse after bone grafting. In steroid-induced ANFH, in three women, 2 of 4 hips showed poor results. These results are only slightly better than those of core decompression and no better than those obtained after decompression and simple nonvascularized grafts to provide support for the subchondral bone. We concluded that vascularized PBG is sometimes indicated for ANFH in an early stage before collapse of the femoral head.     

3D MRI quantification of femoral head deformity in Legg–Calvé–Perthes disease

The purpose of this study was to quantify femoral head deformity in patients with Legg–Calvé–Perthes disease (LCPD) using a novel three dimensional (3D) magnetic resonance imaging (MRI) reconstruction and volume based analysis. Bilateral femoral heads of 17 patients (mean age 9.9 ± 2.0 years; 12 boys, 5 girls) with LCPD were scanned 1–2 times (n = 33 LCPD heads, 20 normal heads) using a 1.5T MRI scanner. Fourteen patients had unilateral and three had bilateral LCPD with five hips in the Waldenström initial stage, 9 in the fragmentation stage, 14 in the reossification stage, and 5 in the healed stage. 3D digital reconstructions of femoral heads were created using MIMICS software. Deformity was quantified using a 3D volume ratio method based on reference hemisphere volume as well as two surface geometry methods. Intra‐observer analysis showed that 97% of the LCPD femoral heads were within 10% of the original value and test shapes had 99.6% accuracy. For normal femoral heads, the volume ratios of all except one were between 95 and 98% (n = 20) of a perfect hemisphere volume. For femoral heads affected with LCPD, the volume ratios ranged from 43% to 96% of a perfect hemisphere (n = 33). The volume ratio method and the two surface geometry comparison methods had high correlation (r = 0.89 and 0.96). In summary, the 3D MRI volume ratio method allowed accurate quantification and demonstrated small changes (<10%) of the femoral head deformity in LCPD. This method may serve as a useful tool to evaluate the effects of treatment on femoral head shape. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2051–2058, 2017.

     

Femoral head osteonecrosis. Detection by magnetic resonance imaging versus single-photon emission computed tomography

Magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) examinations were compared for detection of femoral head osteonecrosis. Of 29 hips with clinical and roentgenographic evidence of osteonecrosis (18 histologically confirmed), 15 were Stage II, three transitional, six Stage III, and five Stage IV. MRI identified osteonecrosis in all 29 cases (100% sensitivity), and there were no false-positives (100% specificity). Of 24 osteonecrotic hips with technically adequate examinations, SPECT identified 14 (sensitivity 58%), and there were four false-positives (78% specificity). If Stages III and IV were eliminated, SPECT correctly identified ten of 15 (67% sensitivity).     

Resurfacing of the femoral head with fresh osteochondral allografts. Long-term results

Twenty-five fresh osteochondral allografts were transplanted in 21 patients. All except one were for avascular necrosis with segmental collapse of the femoral head. One transplant was in a hip with a Pipkin II fracture-dislocation. Most of the failures were in hips of patients receiving systemic steroid therapy. There was an 80% rate of success in non-steroid-treated patients. The allograft resurfacing procedure seems to be a successful intermediate alternative operation in young patients with avascular necrosis and segmental collapse of the head of the femur.     

Correlation of the findings of magnetic resonance imaging with those of bone biopsy in patients who have stage-I or II ischemic necrosis of the femoral head

A prospective study was undertaken to determine the diagnostic accuracy of magnetic resonance imaging in the evaluation of a symptomatic hip for which a diagnosis of early ischemic necrosis of the femoral head was suspected. Fifteen patients (sixteen symptomatic hips), for whom the findings of magnetic resonance imaging were consistent with a diagnosis of osteonecrosis of the femoral head, had a core decompression and a biopsy of the contents of the core. Preoperative magnetic-resonance imaging was useful for planning which segment of the femoral head should be biopsied. Plain radiographs and tomograms of the hips were also made. On the basis of the plain radiographs, ten hips were determined to have Stage-I findings and six hips, Stage-II ischemic necrosis, according to the system of Ficat and of Arlet and Ficat. Histological study revealed evidence of necrosis in all of the biopsy specimens of bone. We concluded that findings of magnetic resonance imaging that are characteristic of osteonecrosis correlate well with the results of biopsies of bone in patients who have an early stage of ischemic necrosis. Magnetic resonance imaging is a highly sensitive and specific method for both the diagnosis and the location of Stage-I and Stage-II osteonecrosis.     

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.     

Natural history of nontraumatic avascular necrosis of the femoral head

We studied the natural history of nontraumatic avascular necrosis of the femoral head (ANFH) in 115 hips in 87 patients, 69 steroid-induced, 21 related to misuse of alcohol and 25 idiopathic. The average length of follow-up was over five years. Collapse occurred most often when the focus of bone necrosis occupied the weight-bearing surface of the femoral head. Flatness of the head due to subchondral fracture was an early manifestation of collapse. Classification into six types based upon the radiographic findings provided an accurate prognosis for individual cases of ANFH which is useful in planning treatment and in assessing its outcome.