Spontaneous osteonecrosis of the knee associated with tibial plateau and femoral condyle insufficiency stress fracture

The purpose of this article is to describe the association between spontaneous osteonecrosis and insufficiency stress fractures of the knee. To determine whether insufficiency stress fracture is associated with spontaneous osteonecrosis of the knee, we retrospectively reviewed the medical charts and imaging studies of all patients with spontaneous osteonecrosis of the knee, studied by MR imaging, seen in a tertiary hospital over an 8-year period. Four women (age range 66–84 years) presented spontaneous osteonecrosis of the knee associated with insufficiency stress fracture of the medial tibial plateau. One of these patients also presented a concomitant insufficiency stress fracture of the medial femoral condyle. Radiographs were diagnostic of spontaneous osteonecrosis of the medial femoral condyle in three cases, and insufficiency stress fracture of the medial tibial plateau was detected in one case. Magnetic resonance imaging allows the diagnosis of both conditions in all four cases. Spontaneous osteonecrosis of the knee may be associated with insufficiency stress fracture of the medial femoral condyle and the medial tibial plateau. This association provides additional arguments in favor of the traumatic etiology of spontaneous osteonecrosis of knee.     

Intramedullary Nailing of Tibial Stress Fractures

Intramedullary nailing of tibial stress fractures is a viable option in a very limited subset of patients that fail nonoperative management. It may be more likely to be required in those patients with the more difficult anterior stress fracture variant. The primary limitation of the technique, however, is the potential for the development of anterior knee pain that may itself be disabling in the athlete. There is at least some risk that anterior knee pain, if it develops, may persist following nail removal. A peritendinous incision is still recommended although strict literature support is lacking, and burying the nail in the bone as evidenced on the lateral radiograph remains a good practice. Although it may be debated whether or not medial tibial stress syndrome represents a precursor lesion to tibial stress fracture, distinguishing between the 2 entities is important when posteromedial tibial pain persists. The former may be treated with a release of the soleus bridge, whereas intramedullary nailing (with its attendant risks) is the preferred choice for a persistent stress fracture.     

Occult intraosseous fracture: magnetic resonance appearance versus age of injury

Twenty-two cases of occult intraosseous fracture in the region of the knee are presented. Occult intraosseous fractures have been incidentally detected in the magnetic resonance (MR) evaluation of the knee in the setting of a recent physical injury and normal radiographic studies. There is no unique mechanism of injury, but occult intraosseous fracture presumably results from direct impaction or axial overloading. MR shows speckled or band-like areas of low signal in the intramedullary space of the epiphyses, and occasionally, the adjacent metaphyses. In most cases, T2-weighted images show high signal in corresponding regions of variable size. The relative extent of high signal findings is shown to vary significantly with the age of injury. Individual variability within groups, however, precludes the actual prediction of lesion age on the basis of the MR appearance. Our observations provide indirect evidence that the findings on T2-weighted images resolve earlier than the corresponding findings on T1-weighted proton density images. The primary differential diagnosis in cases of occult intraosseous fracture is stress fracture. The diagnosis of occult intraosseous fracture may be important in explaining persistent pain after injury in otherwise normal knees.     

Fabella fracture with CT imaging: a case report

Fracture of the fabella is rare, may be easily overlooked, and can be a clinically important cause of posterolateral knee pain following traumatic injury or total knee arthroplasty. To date, nine case reports of fabella fracture with radiographic documentation have been reported in the literature. This report documents a 55-year-old male pedestrian who was struck by an automobile and presented with radiographs demonstrating depressed lateral tibial plateau and proximal fibula fractures. Computed tomography (CT) was performed for surgical planning and demonstrated the additional finding of a radiographically occult nondisplaced fabella fracture. To the best of our knowledge, this is the first case in which CT documentation of a fabella fracture is reported. Fracture of the fabella is a rare but important clinical entity which may be overlooked clinically and radiographically. Clinical information can provide a high index of suspicion, and when coupled with radiographic and CT findings, may lead to the correct diagnosis. CT imaging of the knee may confirm a suspected fabella fracture or may help detect a radiographically occult fracture.     

Rara fractura de estrés: fractura longitudinal del fémur

42-year-old man with pain in the posterolateral region of the right knee that began while he was running. Initially, it was diagnosed by magnetic resonance (MR) as a possible aggressive process (osteosarcoma or Ewing's sarcoma) but with computed tomography it was noted a cortical hypodense linear longitudinal image with a continuous, homogeneous and solid periosteal reaction without clear soft tissue mass that in this patient suggest a longitudinal distal femoral fatigue stress fracture. This type of fracture at this location is very rare. Stress fractures are entities that can be confused with an agressive process. MR iscurrently the most sensitive and specific imaging method for its diagnosis.     

The reverse Segond fracture: not associated with knee dislocation and rarely with posterior cruciate ligament tear

The aims of this study were to assess the incidence of reverse Segond fracture, to examine the associated ligamentous injuries, and to examine how often reverse Segond fracture coexists with a knee dislocation. At a level 1 trauma center, an 11-year period of emergency department multidetector-row computed tomography (MDCT) examinations for knee trauma was evaluated for reverse Segond and Segond fractures. Surgical findings served as the reference standard for intra-articular injuries. The hospital discharge register was searched for the diagnosis of knee dislocation from August 2000 through the end of August 2011. A total of 1,553 knee MDCT examinations were evaluated. Ten patients with a reverse Segond fracture were found, comprising 0.64 % of emergency room acute knee trauma MDCT examinations. Seven patients who had a reverse Segond fracture were operated: Three had an avulsion fracture of the anterior cruciate ligament, one had an avulsion fracture of posterior cruciate ligament, two had a lateral meniscal tear, and two had a medial collateral ligament tear. The ratio of reverse Segond fractures to Segond fractures was 1:4. None of the 71 knee dislocation patients had a reverse Segond fracture. Reverse Segond fracture is a rare finding even in a level 1 trauma center. Cruciate ligament injuries appear to be associated with avulsion fracture, but every patient does not have PCL injury, as previously reported. Our results do not support the association of knee dislocation with reverse Segond fracture.     

Chronic anterior midtibial stress fractures in athletes treated with reamed intramedullary nailing

BACKGROUND: A chronic anterior midtibial stress fracture is a serious, difficult-to-treat injury that can adversely affect an athlete's career. HYPOTHESIS: The use of a reamed intramedullary nail for a chronic anterior tibial stress fracture is a safe and effective treatment for an athlete. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Seven collegiate-level athletes with 11 chronic anterior midtibial stress fractures were treated with reamed intramedullary nailing between 1997 and 2000. These patients were followed for a mean duration of 17 months. RESULTS: The mean age of the patients at the time of stress fracture diagnosis was 17 years. Seven of the fractures occurred in male athletes, whereas 4 occurred in female athletes. All patients had failed nonoperative treatment, including rest, activity modification, use of an orthosis, and low-intensity ultrasound stimulation, for a minimum of 4 months. Patients had experienced symptoms for a mean duration of 12 months. Clinical and radiological union occurred at a mean of 2.7 and 3 months, respectively. The mean duration for return to sports after surgery was 4 months. At last follow-up, all patients had full range of motion at the knee and ankle joints and were satisfied with the results. One patient developed bursitis at the tibial nail insertion site that was resolved with a steroid injection. Another patient sustained a traumatic fracture of the distal tibia 1 year after intramedullary nailing of the tibial stress fracture. This fracture healed with nonoperative treatment. No other complications were observed. CONCLUSION: Intramedullary nailing of the tibia for chronic stress fracture has a high union rate, allows for a low complication rate, and allows for an early return to competitive sports. This procedure is an excellent alternative treatment for those fractures that have failed nonsurgical treatment.     

Osteopathia striata and focal dermal hypoplasia

A 43-year old female, presenting with pain in the left knee, attributed to a stress fracture of the tibia, was found to have osteopathia striata and numerous other congenital anomalies, not only of the skeleton, but also of other tissue systems. Of the latter the most important was the presence of focal dermal hypoplasia, a disorder of the skin. Review of the radiological and dermatological literature has shown this to be the fourteenth case in which these excessively rare entities have been associated. Such an association is considered to be more than a coincidence. A radiological diagnosis of osteopathia striata, therefore, should be followed by a careful dematological examination for focal dermal hypoplasia. Conversely, diagnosis of this rare dermatological disease should indicate the necessity for radiological survey of the skeleton.     

膝部急性隐匿性骨损伤的MRI评价

目的:评价MRI对膝部急性隐匿性骨损伤的诊断价值.方法:回顾性分析113例符合纳入条件的急性膝部创伤患者的MRI图像,采用Mink膝部隐匿性骨损伤分类方法进行观察.结果:骨挫伤71例,骨软骨损伤25例,隐匿骨折15例,应力骨折2例.这些损伤的MRI表现形态各异,信号特点较为一致,以T1WI和STIR显示较好.结论:MR...     

Segond tibial condyle fracture: lateral capsular ligament avulsion

Avulsion fractures in the appendicular skeleton are a result of stress on a specific structure that is firmly attached to bone. A small avulsion fracture from the directly lateral surface of the lateral tibial condyle results from excessive tension on the lateral capsular ligament of the knee joint. Recognition of this fracture on an anteroposterior radiograph of a traumatized knee represents substantial evidence of major injury to the lateral joint capsule. This fracture also has a strong association with rupture of the anterior cruciate ligament. The avulsed tibial fragment is remarkably constant in site and appearance. The typical fragment is isolated by a longitudinal fracture line separating a small piece of bone from the lateral tibia. It is elliptical in outline (10 X 3 mm), with its proximal border lying 4 mm distal to the subarticular cortex of the lateral tibial condyle. A hemarthrosis of the knee joint is consistently visible.     

Neuroarthropathy of the extremities: magnetic resonance imaging features

The objective of this article was to review the magnetic resonance imaging (MRI) findings of four different neuroarthropathic extremities, and discuss the role of MRI in establishing a correct diagnosis. The shoulder, ankle, and knee had predominantly atrophic neuroarthropathic changes, whereas both atrophic and productive changes could be seen in the elbow. Bone marrow edema, suggesting a recent stress fracture, was detected in the elbow and knee. Osteochondral defects, or “detritic” synovitis with effusion, were extensive in all joints but exceptionally profound in the shoulder with amputation-like osteolysis and a total loss of the humeral head. Radiologists may encounter the joint manifestations of neuropathy, which may be confused with various pathologies, including tumor and septic arthritis, before the neurological diagnosis is established. MRI is helpful in detecting the extension of the disease as well as to differentiate chronic Charcot's arthropathy from septic arthritis before radiographic findings suggest the diagnosis.     

Imaging of lower extremity stress fracture injuries

Stress reactions and stress fractures in the lower extremities occur frequently in military and athletic populations. As the clinical symptoms of stress fracture may mimic other less severe musculoskeletal injuries, the diagnosis of stress fracture can often be delayed. The following article reviews the characteristics, advantages and disadvantages of the various imaging tools available to detect stress fracture of the lower limbs in order to clarify their utility when diagnosing this condition. Plain radiography, the primary imaging tool for diagnosing suspected stress injuries, may not detect stress fracture injury until fracture healing is well underway. In some cases of suspected stress fracture, this delay in diagnosis can lead to catastrophic fracture and surgical intervention. Bone scintigraphy has long been recommended for the diagnosis of stress fracture, claiming that skeletal scintigraphy is 100% sensitive for the detection of stress fracture. However, there is a potential for a false negative examination and findings might be nonspecific as tumours or infections may mimic stress injury. In addition, bone scintigraphy involves ionizing radiation and it should not be used whenever there is an alternative. Computed tomography (CT) provides exquisitely fine osseous detail, but should be reserved only for specific indications because it also involves ionizing radiation. Magnetic resonance (MR) imaging, which is noninvasive, has no ionizing radiation, is more rapidly performed than bone scintigraphy, and should be the method of choice for stress fracture diagnosis whenever it is available. However, using MR imaging demands an experienced diagnostician in order to decrease reported false-positive injuries. The ultrasonography technique, which is being used increasingly in the evaluation of the musculoskeletal system has recently been shown to have some potential in the diagnosis of stress fracture; however, currently the imaging modalities are insufficient. The peripheral quantitative CT (pQCT) device, which has been developed to specifically assess skeletal status of the extremities, provides data on bone geometry, strength and density. However, the pQCT needs further evaluation prior to being considered for use in diagnosis stress changes in bone. This article reviews the utility of each of the imaging modalities currently available to detect stress fracture injuries of the lower extremities, as well as other utilization factors, which include exposure to ionizing radiation, the ability to detect early- and late-stage reactions in the bone and surrounding soft tissues, and the ability to differentiate between different types of bone lesions.     

膝关节隐性骨折的磁共振诊断价值探讨

目的 探讨膝关节隐性骨折的磁共振诊断及临床应用价值.方法 对40例膝关节外伤后X线片显示阴性患者行磁共振成像(MRI)检查,8例同时行CT检查.磁共振检查序列包括T1WI、T2WI、STIR.结果 共发现27例45处隐性骨折病灶,其中T1WI序列显示42处,T2WI序列显示39处,STIR序列全部显示隐性骨折病灶.结论 MRI是诊断膝关节隐性骨折的最佳影像学检查方法,能清晰显示隐性骨折的的水肿和骨折线.     

Insufficiency fractures of the tibial plateau

An insufficiency fracture of the tibial plateau may be the cause of knee pain in patients with osteoporosis. The diagnosis is usually not suspected until a bone scan is done, as initial radiographs are often negative or inconclusive and clinical findings are nonspecific and may simulate osteoarthritis or spontaneous. In five of 165 patients referred for bone scans due to nontraumatic knee pain, a characteristic pattern of intense augmented uptake of radionuclide confined to the tibial plateau led to a presumptive diagnosis of insufficiency fracture, later confirmed on radiographs.     

膝关节外伤性骨软骨骨折的X线和MRI表现

目的 探讨膝关节骨软骨骨折的X线和MRI表现.方法 12例膝关节外伤患者分别行X线平片及MR检查，回顾分析其表现并与关节镜及手术对照.结果 12例患者MRI诊断13处膝关节骨软骨骨折，7处位于股骨外髁，6处位于髌骨，同时可见9块游离骨折片，MRI能清楚地显示骨软骨骨折的确切部位、大小、程度，而且能分辨出骨折块的软骨成分及软骨下骨质成分，T2WI、短时反转恢复(STIR)、快速梯度回波(FFE)T2WI序列三者结合显示骨软骨骨折最为清楚。X线检查可见5例关节内游离骨块，不能明确来源。结论 MRI能准确显示并诊断膝关节外伤后骨软骨骨折，提高临床诊断并指导关节镜及手术治疗。X线为膝关节骨软骨骨折的最基本手段，明确诊断应结合MR检查。     

Avulsion fracture of the tibial eminence associated with severe medial ligamentous injury in an adolescent. A case report and literature review

In the presence of open physes, tibial eminence fractures are usually isolated injuries. However, adults sustaining a fracture of the tibial eminence are more likely to have other associated injuries, most commonly a tear of the medial collateral ligament. A case of an adolescent with a tibial eminence fracture and a complete tear of the medial collateral ligament is reported. Review of the literature revealed two similar cases in adolescents. If medial instability is demonstrated on valgus stress of the knee in an adolescent with tibial eminence fracture, we believe stress roentgenograms of the knee should be obtained to distinguish between physeal injury and collateral ligament tear.     

手术治疗胫骨平台骨折的方法策略和进展研究

随着高能量损伤的增加,胫骨平台骨折(tibial plateau fracture,TPF)发病率呈逐渐上升的趋势,处置不当会导致膝关节疼痛和功能障碍的发生,给患者的生活造成严重的影响,因此临床中对疾病的诊断和治疗显得尤为重要.手术治疗作为胫骨平台骨折最主要的治疗方式,明确胫骨平台骨折的类型,选择个体化治疗方案,追求胫骨平台骨折的最佳治疗效果是我们努力的目标.     

Postpartum osteoporosis associated with proximal tibial stress fracture

A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture.     

DR数字成像在膝关节摄影中的应用价值

目的：探讨DR（digital Radiography,DR）数字成像在膝关节摄影中的的临床应用价值。方法：回顾分析400例DR数字成像膝关节摄影的X线照片质量,并加以总结。结果：400例膝关节DR照片中,甲级片378例,占94．50％,乙级片22例,占5．50％。膝关节退行性改变48例,占12．00％,髌骨骨折65例,占16．25％,股骨下段骨折32例,占8．00％,胫腓骨上段骨折37例,占9．25％,胫骨上段骨折35例,占8．75％,腓骨上段骨折22例,占5．50％,其余病例正常。结论：DR系统在骨与关节、软组织的X线诊断中已广泛应用,检查简便、经济,是有效影像学检查方法之一。