Subchondral insufficiency fracture of the femoral head and medial femoral condyle

This case report documents the clinical, radiographic, and histologic findings in a 69-year-old obese man, who had subchondral insufficiency fracture both in the femoral head and medial femoral condyle. On plain radiographs, both lesions underwent subchondral collapse. Magnetic resonance images of the left hip showed a bone marrow edema pattern with associated low-intensity band on T1-weighted images, which was convex to the articular surface. The histopathologic findings in the hip and knee were characterized by the presence of a subchondral fracture with associated callus and granulation tissue along both sides of a fracture line. There was no evidence of antecedent osteonecrosis. To our knowledge, this is the first case report to describe the multiple occurrence of collapsed subchondral insufficiency fracture. Received: 22 May 1999 Revision requested: 5 August 1999 Revision received: 13 September 1999 Accepted: 15 September 1999     

Subchondral insufficiency fracture of the femoral head in younger adults

We report two cases of subchondral insufficiency fracture of the femoral head observed in younger adults without any history of overexertion. In both cases, MRI revealed an irregular, discontinuous low-intensity band on the T1-weighted images. Both patients were treated operatively, and histological examination confirmed the diagnosis of subchondral fracture. A diagnosis of subchondral insufficiency fracture needs to be put in as one of the diagnoses in younger patients with a hip pain.     

Subchondral insufficiency fracture of the femoral head in young adults

A subchondral insufficiency fracture of the femoral head (SIF) is generally observed in elderly women. In addition, SIF has been reported to occur in young military trainees, which are considered to be due to a fatigue stress fracture. This report reviewed five cases of SIF in young adults without any history of overexertion or antecedent trauma. The clinical findings, time to the initial radiograph, time to the initial magnetic resonance imaging (MRI), and follow-up period were investigated. Radiographs and MRI were obtained in both hips. Bone mineral density and bone scintigram were performed. Measurements of a bone mineral density indicated presence of osteopenia in three patients. MRI disclosed a discontinuous irregular-shaped low-intensity band surrounded by bone marrow edema in all cases. After conservative treatments, one patient's condition resolved, while four patients underwent femoral head collapse resulting in surgical treatment. In these four patients, the diagnosis of SIF was histologically confirmed. In addition, the histological findings showed thin disconnected bone trabeculae, thus indicating the presence of some degree of osteopenia. These patients were considered to demonstrate an insufficiency fracture rather than a fatigue stress fracture based on both clinical findings and histological findings. SIF needs to be considered in patients presenting with hip pain even in young cases.     

Subchondral insufficiency fracture of the femoral head after liver transplantation

A 53-year-old woman developed a subchondral insufficiency fracture of the right femoral head after undergoing a liver transplantation. Radiographs obtained at her first visit demonstrated a slight subchondral collapse in the superolateral portion of the femoral head. Magnetic resonance imaging (MRI) disclosed an irregular, discontinuous, low-intensity band on the T1-weighted image. After 7 months of conservative treatment, the hip pain and the radiograph abnormalities had both disappeared. On the follow-up T1-weighted MR image obtained 17 months after the onset, the band of low signal intensity was not obvious. A subchondral insufficiency fracture is one of the diagnoses to be considered in patients presenting with hip pain after a liver transplantation. This work was supported in part by a research grant for intractable disease from the Ministry of Health and Welfare of Japan and a research grant from the Univers Foundation.     

Subchondral insufficiency fracture of the femoral head: histopathologic correlation with MRI

Objective. To correlate the magnetic resonance imaging (MRI) features with the histopathologic findings in subchondral insufficiency fracture (SIF) of the femoral head. Design and patients. This study was based on a retrospective review of the MRI features and histopathologic findings in seven patients with SIF who had had total hip replacement. Results. In all seven cases, MRI showed a bone marrow edema pattern in the femoral head, and a focal low-intensity band beneath the articular cartilage on some slices (not all) on the T1-weighted images. The shape of the low-intensity band varied: it was irregular and serpentine in four cases, well-delineated, smooth, and a mirror image to the articular surface in two cases, and parallel to the articular surface in one case. On histologic examination, the low-intensity band on MRI corresponded to a fracture line and its associated repair tissue. In all but one case, the band was not visible on T2-weighted or fat suppression images, and the proximal subchondral portion of the lesion had a homogeneous high signal intensity. This region of high signal intensity corresponded histopathologically to viable bone and marrow tissue with associated callus, edema, and vascular granulation tissue. Conclusions. SIF of the femoral head characteristically demonstrates a low-intensity band on T1-weighted images that corresponds, histopathologically, to a linear subchondral fracture and its associated repair tissue. In most cases, the subchondral portion of the lesion appears on T2-weighted images as an area of homogeneously high signal intensity. Received: 1 June 2000 Revision requested: 17 August 2000 Revision received: 11 October 2000 Accepted: 9 January 2001     

Subchondral insufficiency fractures of the femoral head

The aim of this study was to increase awareness of, and to show the variable clinical and radiological features of, subchondral insufficiency fractures of the femoral head. The clinical and radiological findings in 7 patients with subchondral insufficiency fractures of the femoral head were reviewed retrospectively. The diagnosis was confirmed histologically in 4 patients. Radiographs were performed in all patients, MRI in 5 and scintigraphy in 4 patients. Radiographs showed varying degrees of femoral head collapse in 4 patients. In the remaining 3 patients radiographs showed a normal femoral head, regional osteoporosis and focal sclerosis, respectively. Magnetic resonance imaging showed a low-signal band on T1- and T2-weighted images in the subchondral bone adjacent or parallel to the articular surface associated with bone marrow oedema. Scintigraphy showed increased uptake in the femoral head. Insufficiency fractures of the femoral head are easily overlooked or confused with avascular necrosis and, when there is significant joint destruction, osteoarthritis. Unsuspected insufficiency fracture of the femoral head can lead to significant and rapid loss of bone stock in osteoporotic patients waiting for arthroplasty for osteoarthritis. Increased awareness of this condition will hopefully lead to earlier diagnosis and a successful outcome of conservative treatment.     

Subchondral insufficiency fracture of the femoral head after internal fixation for femoral neck fracture: histopathological investigation

Late segmental collapse after internal fixation for femoral neck fracture is the phenomenon observed in post-traumatic osteonecrosis of the femoral head (ON), which has generally been reported to occur over a year or more after internal fixation. Subchondral insufficiency fracture of the femoral head (SIF) has also been recognized to cause femoral head collapse, however, only two cases of SIF after internal fixation for femoral neck fracture have been reported. We report a case with femoral head collapse observed 5 months after internal fixation for femoral neck fracture, which was histopathologically diagnosed as SIF. Clinically, differentiating SIF from ON is important because some cases of SIF have been reported to heal without surgical treatments. The timing of femoral head collapse after femoral neck fracture may be different between SIF and post-traumatic ON.     

Subchondral insufficiency fracture of the femoral head: a report of two cases with a history of internal fixation of a femoral neck fracture

We report our experience in two cases of subchondral insufficiency fracture of the femoral head with a history of internal fixation of the femoral neck fracture. Both cases were young females (26 and 43 years old, respectively). Their hip pain occurred more than 2 years and 1 year after the primary surgical treatment, respectively. MRI revealed bone marrow edema pattern, as well as a low-intensity band on the T1-weighted images, which are commonly observed in osteonecrosis. However, the low-intensity bands were parallel to the subchondral bone end-plate, which are characteristic findings of subchondral insufficiency fracture. Both patients were administered anti-inflammatory drugs and/or bisphosphonate. One patient underwent a transtrochanteric curved varus osteotomy 1 year and 9 months after the onset, and the other healed without collapse of the femoral head. Our cases indicate that subchondral insufficiency fractures may need to be considered as one of the possible conditions after the internal fixation of a femoral neck fracture, in addition to posttraumatic osteonecrosis.     

Subchondral insufficiency fracture of the femoral head: magnetic resonance imaging findings correlated with micro-computed tomography and histopathology

We described magnetic resonance (MR) imaging findings of subchondral insufficiency fracture of the femoral head without collapse in which micro-computed tomography (CT) and histopathologic studies were performed. Magnetic resonance imaging showed a subchondral low-signal intensity band, which corresponded to the fracture callus. Diffuse bone marrow edema with contrast enhancement effect was seen in both the proximal and distal segments of the low-signal intensity band. These features are distinct from those of avascular necrosis.     

Prognostic factors associated with a subchondral insufficiency fracture of the femoral head

Objective

The aim of this study was to identify the risk factors associated with the prognosis of a subchondral insufficiency fracture of the femoral head (SIF).

Methods

Between June 2002 and July 2009, 25 patients diagnosed with SIF were included in this study. Sequential radiographs were evaluated for the progression of collapse. Clinical profiles, including age, body mass index, follow-up period and Singh’s index, were documented. The morphological characteristics of the low-intensity band on T₁ weighted MRI were also examined with regards to four factors: band length, band thickness, the length of the weight-bearing portion and the band length ratio (defined as the proportion of the band length to the weight-bearing portion of the femoral head in the slice through the femoral head centre).

Results

Radiographically, a progression of collapse was observed in 15 of 25 (60.0%) patients. The band length in patients with progression of collapse [22.5 mm; 95% confidence interval (CI) 17.7, 27.3] was significantly larger than in patients without a progression of collapse (13.4 mm; 95% CI 7.6, 19.3; p<0.05). The band length ratio in patients with progression of collapse (59.8%; 95% CI 50.8, 68.9) was also significantly higher than in patients without a progression of collapse (40.9%; 95% CI 29.8, 52.0; p<0.05). No significant differences were present in the other values.

Conclusion

These results indicate that the band length and the band length ratio might be predictive for the progression of collapse in SIF.Subchondral insufficiency fractures of the femoral head (SIF) often occur in osteoporotic elderly patients [1-9]. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen primarily in the superolateral portion of the femoral head [4,5,10]. T₁ weighted MRI reveal a very low-intensity band in the subchondral area of the femoral head, which tends to be irregular, disconnected and convex to the articular surface [2,4,5,7,9,11]. This low-intensity band in SIF was histologically proven to correspond with the fracture line and associated repair tissue [5,9]. Some cases of SIF resolve after conservative treatment [5,11-14]; other cases progress until collapse, thereby requiring surgical treatment [4-10,15]. The prognosis of SIF patients remains unclear.The current study investigated the risk factors that influence the prognosis of SIF based on the progression to collapse.     

Subchondral bone density distribution in the human femoral head

Objective

This study aims to quantitatively characterize the distribution of subchondral bone density across the human femoral head using a computed tomography derived measurement of bone density and a common reference coordinate system.

Materials and methods

Femoral head surfaces were created bilaterally for 30 patients (14 males, 16 females, mean age 67.2?years) through semi-automatic segmentation of reconstructed CT data and used to map bone density, by shrinking them into the subchondral bone and averaging the greyscale values (linearly related to bone density) within 5?mm of the articular surface. Density maps were then oriented with the center of the head at the origin, the femoral mechanical axis (FMA) aligned with the vertical, and the posterior condylar axis (PCA) aligned with the horizontal. Twelve regions were created by dividing the density maps into three concentric rings at increments of 30° from the horizontal, then splitting into four quadrants along the anterior-posterior and medial-lateral axes. Mean values for each region were compared using repeated measures ANOVA and a Bonferroni post hoc test, and side-to-side correlations were analyzed using a Pearson’s correlation.

Results

The regions representing the medial side of the femoral head’s superior portion were found to have significantly higher densities compared to other regions (p?r ²?=?0.81 to r ²?=?0.16), with strong correlations for the highest density regions. Side-to-side differences in measured bone density were seen for two regions in the anterio-lateral portion of the femoral head (p?Conclusions The high correlation found between the left and right sides indicates that this tool may be useful for understanding ‘normal’ density patterns in hips affected by unilateral pathologies such as avascular necrosis, fracture, developmental dysplasia of the hip, Perthes disease, and slipped capital femoral head epiphysis.     

股骨头骨折的治疗

目的 探计股骨头骨折的治疗方法．方法 对57例股骨头骨折进行随访．分析各种不同治疗方法的治疗效果．进行对比研究．结果 股骨头骨折的治疗效果与Pipkin分型、手术入路．固定方式和术后治疗都有关系。结论 股骨头骨折应根据其分型选择治疗方法,手术应尽量在6小时内进行,手术人路应综合多方面因素进行选择．内固定方式以可吸收钉棒为佳．术后应早活动、晚负重。     

双极人工股骨头置换治疗高龄股骨颈骨折的疗效分析

目的探讨高龄股骨颈骨折应用双极人工股骨头置换的临床疗效。方法对63例高龄股骨颈骨折患者行骨水泥固定的国产双极人工股骨头置换,术后根据Harris评分法和X线资料评定其疗效。结果本组63例均成功完成手术,术中无血管神经损伤。术后无切口感染和关节脱位,无围术期死亡。术后随访10～42(15.3±2.1)个月。术后合并肺部感染6例,泌尿系感染5例,下肢深静脉血栓形成3例,中枢神经系统功能障碍2例,脑梗死1例。X线片检查显示髋关节间隙变窄11例,假体轻度内翻5例,出现假体下沉3例,骨水泥周围<2 mm的透亮带2例。根据Harris评分法评定,优22例,良26例,中12例,差3例,优良率76.19%。结论应用骨水泥固定的双极股骨头置换治疗高龄股骨颈骨折疗效满意。     

A histopathological evaluation of a concave-shaped low-intensity band on T1-weighted MR images in a subchondral insufficiency fracture of the femoral head

A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped low-intensity area just beneath the articular cartilage as well as a low-intensity band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-intensity band observed on the T1-weighted image.     

老年人工股骨头置换术后假体周围骨折的处理

10例人工股骨头置换术后股骨假体周围骨折根据Vancouver方法分型,不同类型骨折选择合理的个性化的治疗。随访8.3～20.2个月,骨折均愈合,愈合时间4.4～9.6个月;9例患肢功能基本恢复正常,1例患肢行走明显跛行。     

创伤性髋关节后脱位伴股骨头骨折的治疗

通过对14例创伤性髋关节后脱位伴股骨头骨折的治疗,分析总结手术方法、手术入路及内固定物选择对治疗效果的影响。