Osteonecrosis of the femoral head extending into the femoral neck

Osteonecrosis of the femoral head (ONFH) is an ischemic disorder that can lead to femoral head collapse and secondary osteoarthritis. Although the condition is usually limited to the femoral head, we report a rare case of biopsy-proven ONFH extending into the femoral neck, which required hip replacement surgery. We emphasize the imaging features of this condition and briefly discuss its potential relevance.     

股骨重建钉治疗股骨干合并同侧股骨颈骨折

目的评价股骨重建钉治疗股骨干合并同侧股骨颈骨折的效果,并探讨相关注意事项。方法应用该方法治疗股骨干合并同侧股骨颈骨折15例。结果 15例患者平均随访16个月,术后切口均Ⅰ期愈合,骨折平均愈合时间:股骨颈骨折5个月,股骨干骨折6个月。无髓内钉及锁钉断裂、股骨头坏死、感染及脂肪栓塞,关节功能活动正常。结论采用闭合复位或有限切开复位、股骨重建钉固定治疗股骨干合并同侧股骨颈骨折,可减少对骨折端血运的破坏,减少出血,减少对患者的损伤,有利于骨折的愈合,有临床应用价值。     

Evaluation of the hemodynamics of the femoral head compared with the ilium, femoral neck and femoral intertrochanteric region in healthy adults: Measurement with positron emission tomography (PET)

OBJECTIVE: Non-traumatic osteonecrosis of the femoral head (ONF) is considered to be a disease that occurs primarily due to ischemia of the femoral head, while its etiology and pathology are not fully understood. It is therefore necessary to identify the characteristics of the hemodynamics of the femoral head. In this study, the hemodynamics in the ilium and proximal regions of the femur, including the femoral head, was investigated using positron emission tomography (PET). METHODS: The subjects of this study consisted of 8 hip joints of four healthy male adults and 3 hip joints on the contralateral side of a femoral neck fracture, avulsion fracture of the greater trochanter and coxarthrosis (1 case each, all females) for a total of 11 hip joints of 7 subjects. The ages of the subjects ranged from 25 to 87 years (average age: 54 years). Blood flow was measured by means of the H215O dynamic study method and blood volume was measured by means of the 15O-labeled carbon monoxide bolus inhalation method. RESULTS: Blood flow was determined to be 9.1 +/- 4.8 ml/min/100 g in the ilium and among proximal regions of the femur (femoral head, neck and intertrochanteric region), 1.8 +/- 0.7 ml/min/100 g in the femoral head, 2.1 +/- 0.6 ml/min/100 g in the femoral neck, and 2.6 +/- 0.7 ml/min/100 g in the intertrochanteric region. In addition, blood volume was 4.7 +/- 1.3 ml/100 g in the ilium, and among proximal regions of the femur, 1.1 +/- 0.5 ml/100 g in the femoral head, 2.1 +/- 0.7 ml/100 g in the femoral neck, and 2.6 +/- 0.9 ml/100 g in the intertrochanteric region. The results showed that both blood flow and volume were lowest in the femoral head. Blood flow and volume were significantly lower in the proximal regions of the femur (femoral head, neck and intertrochanteric region) than in the ilium (p < 0.01). CONCLUSION: The present study demonstrated that the femoral head is in a hypoemic state as compared with other osseous tissue, indicating that even the slightest exacerbation of hemodynamics in the femoral head can trigger an ischemic condition culminating in ONF.     

股骨转子重建、人工股骨头置换治疗高龄患者非稳定性股骨转子间骨折

目的 探讨采用股骨转子重建、人工股骨头置换治疗高龄患者非稳定性股骨转子间骨折的疗效.方法 本组106例,其中男45例,女61例;年龄80～105岁,平均88岁.大部分为滑倒跌伤.骨折按Evans分型:ⅢA型31例,ⅢB型45例,Ⅳ型30例.均采用股骨转子重建、骨水泥型普通双极人工股骨头置换术.采用4种方法对股骨转子间骨折进行了重建:(1)股骨大转子复位后采用"∞"字钢丝张力带固定;(2)股骨小转子复位后用钢丝绕股骨近端骨皮质环扎固定;(3)股骨距部位的骨缺损用骨水泥充填、重塑;(4)部分股骨颈基底较完整者,在股骨颈截骨变转子间骨折为股骨颈骨折,保留的股骨距用插入的人工股骨柄固定.结果 全部患者均顺利通过手术,手术时间45～70 min,平均55 min.79例获随访,时间6～48个月,平均16个月.无晚期关节松动、脱位或感染,优良率达87.3%.结论 采用股骨转子重建、人工股骨头置换治疗高龄患者非稳定性股骨转子间骨折可恢复股骨近端解剖,稳定髋关节,使患者术后早期下床,改善高龄患者的生活质量,降低病死率.     

AO股骨近端髓内钉在股骨转子间骨折治疗中的应用

目的 讨论应用国际内固定研究学会(AO)股骨近端髓内钉(PFN)治疗股骨转子间骨折的临床疗效.方法 应用AO产 PFN 治疗股骨转子间骨折35例,并随访疗效.结果 34例获得随访,时间6～24个月,平均14个月,骨折全部愈合,髋关节功能优良31例(91.2%).结论 AO股骨近端髓内钉治疗股骨转子间骨折具有手术创伤小、微创、固定牢靠、病人可早期进行功能活动,并发症少等优点,是目前治疗股骨转子间骨折较理想的内固定物.     

Influence of femoral rotation on femoral offset determined from radiographs

To study how the size of femoral offset, judged from radiographs, depends on the femur's degree of internal–external rotation during radiography, this report studied 108 hips (55 right, 53 left; 60 male, 48 female).For each hip, the femoral offset was determined from radiographs taken with the femur in 15 degrees of internal rotation (standardised femoral offset), and also from radiographs taken when no special attempt was made to have the femur in this position (control femoral offset – corrected for magnification).Control femoral offset (corrected) was less than the standardised femoral offset in 102 of 108 hips. On average, for the 108 hips as a group, control femoral offset (corrected for magnification) was 7.7 (CI 8.7, 6.6) mm smaller than standardised offset, a significant difference (p < 0.0001, t-test, two-tailed). For individual hips, the difference was as great as 25 mm.Depending on the femoral rotation during radiography, calculating femoral offset from x-rays may underestimate the femoral offsets sufficiently to compromise hip joint replacement in clinical orthopaedic practice.     

Ultrasound-guided antegrade femoral access: comparison between the common femoral artery and the superficial femoral artery

Purpose  

The aim of this study was to compare ultrasound-guided access of the superficial femoral artery and the common femoral artery.     

老年人股骨颈骨折股骨头置换术中短柄假体的有限元分析

目的针对老年人股骨颈骨折后假体置换术,使用有限元分析的方法对股骨短柄假体与常规股骨假体的生物力学特性进行对比。方法利用薄层CT资料建立股骨三维有限元模型,利用我院股骨中空多孔股骨假体相关参数建立两种髋关节股骨假体三维有限元模型;应用Ansys 5.7有限元分析软件考察两种假体植入后的应力分布,并进行比较。结果短柄假体所受最大mises应力较常规股骨假体明显减小;力学传导模式仍为远端应力集中,最大mises应力仍出现在张力侧。结论老年人股骨颈骨折关节置换术中短柄假体力学特性优越。     

人工关节置换治疗晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形

目的 探讨晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者采用普通假体髋关节置换的手术方法及临床疗效.方法 本组男9例,女6例;年龄30～42岁,平均37岁.前倾角40°～50°,术前Harris评分(59±8)分,术中通过将股骨假体缩小前倾角20°～30°,同时将髋臼杯前倾角增大10°～15°,使其基本恢复正常对合关系,防止关节前脱位.术后定期影像学检查和临床疗效Harris髋评分.结果 术后15例患者均获得随访2.5～3.7年(平均2.9年),关节假体稳定性良好,关节活动度基本正常.术后2年Harris评分为(88±6)分,与术前相比,疗效显著(P<0.01).结论 晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者手术中通过对普通的股骨假体及髋臼杯安放的角度的联合调整,使关节置换术后人工假体与髋臼的对合基本恢复正常,疗效显著,同时避免了使用小柄股骨假体、转子下截骨或使用特殊前倾角股骨假体等治疗方法.     

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.     

Native femoral sulcus as a guide for the position of the femoral component in primary total knee arthroplasty

A prospective randomized study was conducted to evaluate the effects of using the native femoral sulcus as a guide for the positioning of the femoral component in primary total knee arthroplasty (TKA), especially for patellar tracking. Between 2000 and 2002, 420 cases of primary TKA were collected. All the TKAs were performed with the same approach. The cases were randomly separated into two groups. In group 1 (consisting of 202 knees), the femoral insertion of the posterior cruciate ligament and the midline of the lateral–medial femoral condyles were used as a guide for the midline position of the femoral component; while in group 2 (consisting of 218 knees), the native femoral sulcus was used as the guide for the femoral component. Intraoperatively, no thumb technique was used to check the patellar tracking. In group 1, 16 knees (7.9%) received lateral retinacular releases, while none received lateral retinacular release in group 2 (P<0.0001). The average (range) follow-up period was 40 (30–56) months. In postoperative radiographic evaluation, two knees (1%) of lateral tilting of the patella were noted in group 1; while two knees (0.91%) of lateral tilting of the patella were noted in group 2 (P=0.751). In conclusion, native femoral sulcus could be a very effective and simple guide for the medial-lateral position of the femoral component, especially for patellar tracking.The prostheses used in this series were all Nexgen LPS-FLEX PCL Substituting (Zimmer, Warsaw) prostheses.     

Iatrogenic femoral arteriovenous fistula

Twelve iatrogenic femoral arteriovenous fistulas are reported, 11 of which arose from the superficial or deep femoral arteries. All but two occurred in association with cardiac angiographic procedures. It appears that the femoral crease was used as a landmark to establish the cutaneous entry point for vascular puncture and resulted in an excessively distal puncture site. The femoral crease is an unreliable landmark in many patients. This complication may be minimized by using physical examination to identify the level of the inguinal ligament or fluoroscopy to localize the distal half of the femoral head.     

Large osteochondral defects of the femoral condyle: press-fit transplantation of the posterior femoral condyle (MEGA-OATS)

BACKGROUND AND AIMS: Large osteochondral defects in the weight-bearing zone of the knee remain a challenging therapeutic problem. Surgical options include drilling, microfracturing, and transplantation of osteochondral plugs but are often insufficient for the treatment of large defects of the femoral condyle. PATIENTS AND METHODS: Large osteochondral defects of the femoral condyle (mean defect size 7.2 cm(2) range 3-20) were treated by transplantation of the autologous posterior femoral condyle. Between 1984 and 2000, 29 patients were operated on: in 22 the medial, in 6 the lateral femoral condyle, and in one the trochlear groove was grafted. Thirteen patients underwent simultaneous high tibial valgus osteotomy. In the first series (1984-1999) the graft was temporarily fixed with a screw ( n=12), but from 1999 we used a newly developed press-fit technique ( n=17) avoiding screw fixation of the graft. The operative technique comprising graft harvest, defect preparation, transplantation, and fixation is described. Patients were clinically evaluated using the Lysholm score, and magnetic resonance imaging with intravenous contrast was performed 6 and 12 weeks after surgery (mean follow-up 17.7 months (range 3-46). RESULTS: Pain and swelling were reduced in 26 patients. Three patients of the first series reported persistent problems and were subjectively not satisfied. The mean Lysholm score rose from preoperatively 52 to 77 points after 3 months, 74 after 6, 88 after 12, and 95 after 18. Magnetic resonance imaging showed good graft viability in all cases. We saw one arthrofibrosis after 6 months but noted no problems related to the loss of the missing posterior condyle. CONCLUSION: Large osteochondral defects of the femoral condyle can be treated by transplantation of the autologous posterior femoral condyle. The use of only one osteochondral piece renders better approximation of the femoral cartilage curvature and thus joint congruence than in mosaic plasty. However, whether loss of the posterior condyle has a long-term negative impact on the knee joint remains to be elucidated.     

Influence of the femoral tunnel location and angle on the contact pressure in the femoral tunnel in anterior cruciate ligament reconstruction

BACKGROUND: The causes of bone tunnel enlargement after anterior cruciate ligament reconstruction have not been thoroughly investigated. HYPOTHESIS: A malpositioned femoral tunnel and an acute femoral tunnel angle may increase the mechanical stress in the femoral tunnel. STUDY DESIGN: Controlled laboratory study. METHODS: Three femoral tunnels (normal, anterior, and acute) and the tibial tunnel were made in four fresh-frozen cadaveric knees. Aluminum cylinders containing pressure-sensitive conductive rubber sensors at the joint entrance were inserted into the femoral tunnels. Dynamic changes in the contact pressure of the graft in the femoral tunnel were measured. RESULTS: Peak contact pressures and dynamic changes in contact pressure for the normal and anterior femoral tunnels demonstrated no differences. Maximum contact pressure of the graft was observed at the anterior portion with the knee in full extension and at the posterior portion with deep knee flexion. Consistent contact pressure occurred at the anterior aspect of the acute femoral tunnel throughout the range of motion. Mean contact pressure at the anterior region of the acute femoral tunnel was significantly higher than that of the normal femoral tunnel at 60 degrees, 90 degrees, and 120 degrees of knee flexion. CONCLUSIONS: The consistent contact pressure in the anterior aspect of the acute femoral tunnel may erode the anterior portion of the femoral tunnel, resulting in bone tunnel enlargement. Clinical Relevance: The femoral tunnel direction in anterior cruciate ligament reconstruction is an important factor in reducing femoral tunnel enlargement.     

Radiographic changes of the revascularized femoral head

Twenty-two necrotic femoral heads in young adults were radiologically followed-up after grafting with vascularized bone by comparing the preoperative and the postoperative state of the hip joint. Three parameters were observed and followed; the flattening of the femoral head; the degree of osteoarthrosis of the joint; and the degree of incorporation of the graft into the recipient bone. The results, expressed by index figures, showed that the femoral head flattened during the first two years postoperatively; that the maximal incorporation occurred during the same period of time; and that the appearance of postoperative osteoarthrosis was slow during the first year and increased subsequently. This numerical characterization of radiological findings allows systematic individual analysis after revascularization of the femoral head with bone grafts. It is also suited for comparisons between patients, between series of patients and of various treatment techniques. Furthermore, this quantification provides a numerical index that seems to correlate with the outcome of the treated hip joint.     

Antegrade puncture of the femoral artery: morphologic study

To determine the optimal site for antegrade puncture of the femoral artery, the authors evaluated three cadaver specimens and computed tomographic (CT) scans of 50 patients. The relationships among the common femoral artery, the femoral artery bifurcation, the center of the femoral head, and the inguinal ligament were evaluated. CT showed that the center of the femoral head was always located caudal to the level of the inguinal ligament but cranial to the bifurcation of the common femoral artery. Therefore, the femoral head seems to provide a reliable landmark for entering the common femoral artery.     

Correlation between baseline femoral neck marrow status and the development of femoral head osteonecrosis in corticosteroid-treated patients: a longitudinal study by MR imaging

OBJECTIVE: To test the hypothesis that the development of corticosteroid (CS)-associated femoral head osteonecrosis (ON) is influenced by baseline femoral neck marrow status. PATIENTS AND METHODS: The population consisted of 20 untreated patients with a newly diagnosed rheumatic disease in whom a standardized CS regimen was planned. Before CS treatment, baseline femoral neck marrow status was determined by magnetic resonance (MR) imaging on T1-weighted images (proportion of surface area of femoral neck and intertrochanteric area occupied by fatty marrow; index of marrow conversion [IMC]) and on a quantitative MR sequence (bulk T1 values of femoral head and neck). The presence of ON was assessed by coronal T1-weighted MR images of the hips at 6 and 12 months. RESULTS: None of the patients suffered from ON at baseline. Four patients (20%) developed bilateral femoral head ON at 6 months. The mean percentage of fat marrow in the femoral neck before treatment was significantly higher in ON-positive than in ON-negative patients (p=0.0025). The mean baseline femoral neck IMC value, which parallels the degree of red to yellow marrow conversion, was higher in ON-positive than in ON-negative patients (p=0.089). The mean baseline bulk T1 value of the femoral neck (but not of the femoral head), which inversely correlates with the amount of fat marrow, was significantly shorter in ON-positive than in ON-negative patients (p=0.0298). CONCLUSION: The development of CS-associated femoral head ON is correlated with a high fat content in the proximal femur before CS therapy.     

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     

To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures

Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union.Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties.Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity after femoral neck fracture are 87%, 88% and 87%, respectively. Type A or Type B curve pattern is a positive factor to successful osteosynthesis with p value <0.0001 (Chi-square test). This is a statistically significant value. From this finding it can be suggested that the reliability of dynamic curves A and B in predicting maintained vascularity of femoral head is high. This investigation can be used to predict the vascularity of femoral head after intracapsular femoral neck fractures.There was a good correlation between the outcomes of fractures and dynamic MRI curves done within 48 h of injury. This signifies the role of dynamic MRI in predicting the vascularity of femoral head as early as 48 h.A treatment algorithm can be suggested on the basis of dynamic MRI curves. The fractures with Type C dynamic curve should be considered as fractures with poor vascularity of femoral head and measures to enhance the vascularity of femoral head along with rigid internal fixation should be undertaken to promote revascularization process and better healing of fractures. Patients with these fractures should be on longer non-weight bearing ambulation than other patients.To conclude, the dynamic MRI seems to be reliable, non-invasive, sensitive, specific and accurate method of assessing the femoral head vascularity after intracapsular femoral neck fractures as early as 48 h of injury and to predict the outcome of fractures and may be used as a guideline for management of intracapsular femoral neck fractures.