Unusual proximal dislocation without fracture: a case report.

Carpal instability includes a broad spectrum of osseous and ligamentous injuries which have been subclassified into greater and lesser arc injuries, in addition to combinations of both (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The injuries typically occur from a fall on the outstretched hand with the wrist in ulnar deviation, hyperextension, and intercarpal supination (Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The force classically propagates from the radial to the ulnar side of the wrist resulting in a fracture (greater arc) or dislocation (lesser arc) pattern with the extent of the injury occurring in an orderly pattern depending upon the degree of hyperextension and the duration and magnitude of the force (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). Multiple variations occur, including transradial styloid fractures as well as fractures through carpal bones surrounding the lunate (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985; Kozin SH. J Am Acad Orthop Surg 6 (2): 114-20, 1998. Although carpal dislocations have been noted for many years, the mechanisms and classification have only been recently clarified. We report a case of a complex dislocation involving the entire proximal carpal row without an associated fracture. While this type of complex carpal dislocation has been previously described, to our knowledge, it has never been reported without a fracture of the forearm, wrist, or hand.

High association between accessory soleus muscle and Achilles tendonopathy.

OBJECTIVE: This study investigated the association between accessory soleus muscle and abnormalities of the Achilles tendon. MATERIALS AND METHODS: The authors reviewed 15 consecutive cases with a diagnosis of accessory soleus muscle from a computerized database of ankle magnetic resonance (MR) examinations reported between January 1998 and January 2007. On review, two cases were eliminated because of an incorrect initial diagnosis: One patient had a low lying soleus attachment to the Achilles tendon, while the other had a prominent flexor hallucis longus tendon partially obliterating Kager's fat. The remaining 13 cases with accessory soleus muscles were evaluated for Achilles tendon abnormalities. RESULTS: There were 13 cases of accessory soleus muscles in 11 patients; two patients had bilateral accessory soleus muscles (the only study patients with bilateral MR examinations in our sample). There were five male and six female patients ranging from 15 to 81 years of age (mean 48). There were nine cases (69.2%) in which Achilles tendonopathy was associated with accessory soleus muscle, including tendonopathy of each Achilles tendon in the two patients with bilateral accessory muscles. CONCLUSION: In our small patient population, there was a high association between accessory soleus muscle and Achilles tendonopathy.

Imaging features of crystal-induced arthropathy.

Crystal-induced arthropathies constitute a spectrum of inflammatory arthritides that is induced by cellular reaction to crystal deposition in and around joints. A variety of microcrystals may be deposited and can induce an inflammatory response. The three most common types of crystal-induced arthropathy are gout, calcium pyrophosphate dihydrate deposition disease, and calcium hydroxyapatite deposition disease. Each has a characteristic clinical presentation, crystal type that may be aspirated from affected tissues, and radiographic appearance. Each of these entities may occur as a primary abnormality or secondary to an underlying disorder. Sometimes these diseases may coexist in the same joint or individual. Imaging frequently plays a crucial role in the diagnosis of crystal-induced arthropathies and may help to monitor disease progression and treatment response.

Avascular necrosis and bone marrow edema syndrome.

MR imaging is the most accurate modality for the diagnosis of AVN, bone marrow edema syndrome, and femoral head insufficiency fractures. When the particular demographics of the patient are considered, the specificity of this examination is high. The reported success rates of joint-sparing operative intervention are variable. When compared with conservative management, the outcome of joint-sparing operative intervention in patients who have early (stage I, II) AVN lesions is improved. This is impetus for screening programs for patients who are known to be at high risk for AVN, such as patients who have undergone renal transplants and others who are on long-term, high-dose corticosteroid treatment. There is strong evidence that bone marrow edema syndrome (TO) is a distinct entity with demonstrable unique histopathology and well-defined demographics. Increased spatial resolution revealed typical subchondral findings of AVN in lesions that were once believed to represent irreversible TO. SIF of the femoral head is a new concept with a seemingly distinct population and with clinical presentation and imaging characteristics that should permit its differentiation from AVN.

The incidence of pathology detected by magnetic resonance imaging of the knee: differences based on the specialty of the requesting physician.

The usage patterns of magnetic resonance imaging (MRI) by orthopedic and nonorthopedic surgeons were studied. A sample consisting of the radiologist reports from all knee MRIs in a single year at our institution were reviewed. Studies to evaluate tumors or infections were excluded. Reports were classified as normal or demonstrating degenerative joint disease, meniscal tears, cruciate ligament pathology, collateral ligament pathology, focal chondral defects, chondromalacia patella, cysts, extensor mechanism dysfunction, intraosseous edema, or fractures. Six hundred eighteen reports were reviewed. The combined incidence of a normal study or one that found only degenerative joint disease was 45% for nonorthopedic surgeons and 27.6% for orthopedic surgeons (P<.00001). Given the higher incidence of normal findings in studies ordered by nonorthopedic surgeons, these physicians probably use MRI more for screening whereas orthopedic surgeons are more apt to use it for confirmation. Therefore, if clinical guidelines for using MRI are to be established, differences in use as a function of specialty must be acknowledged.

Utility of flexion and extension radiographs of the cervical spine in the acute evaluation of blunt trauma.

BACKGROUND: The purpose of this study is to investigate the usefulness of flexion and extension radiographs of the cervical spine for the acute evaluation of ligamentous injury in cases of awake blunt trauma. METHODS: A review of 106 consecutive cases of blunt trauma evaluated with flexion and extension radiographs of the cervical spine obtained in the acute setting at a Level I trauma center was performed. The data compiled included the age, sex, mechanism of injury, type of radiographic evaluations, interpretation of all radiographic studies, and clinical outcome on follow-up. RESULTS: Sixty-six of the patients (62%) were involved in motor vehicle crashes. Other injuries included 15 falls (14%), 9 blunt assaults (8.5%), and 16 other types of blunt trauma (15%). Thirteen cervical spine injuries were diagnosed in 9 of 106 patients (8.5%). Injuries included two fractures, eight acute disc herniations, two ligamentous injuries, and one cord contusion diagnosed on the basis of all radiologic evaluation and clinical follow-up. Seventy-four patients (70%) had a range of flexion and extension motion interpreted as adequate for diagnostic purposes. Five of the 74 patients (6.75%) with an adequate range of motion had cervical spine injuries. No ligamentous injuries were misdiagnosed in this group. Thirty-two of the flexion and extension examinations (30%) were interpreted as inadequate because of limited motion. Four of the 32 patients (12.5%) with inadequate flexion and extension examinations had injuries subsequently detected on cross-sectional imaging (computed tomographic scanning or magnetic resonance imaging) including severe ligamentous injury. CONCLUSION: When adequate motion was present on flexion and extension radiographs, the false-negative rate was zero in this study. However, in the acute setting, 30% of the examinations were limited by inadequate motion. A higher percentage of injury (12.5%) was detected by subsequent cross-sectional imaging in these patients. Limited flexion and extension motion on physical examination should preclude the use of flexion and extension radiographs, as they are of limited diagnostic utility. Cross-sectional imaging may be warranted in this high-risk group of patients.

Imaging of athletic injuries to the ankle and foot.

Conventional radiographs in conjunction with clinical examination remains the primary method for evaluating the acute athletic injury. In most cases, suspected acute tendon and ligament injuries are initially treated based on physical examination. Magnetic resonance (MR) imaging, with its multiplanar capability and superb soft tissue contrast, is quickly becoming the method of choice for evaluating chronic foot and ankle pain and further defining the extent of tendon and ligament injuries. This article reviews the common acute and chronic (overuse) foot and ankle athletic injuries with an emphasis on imaging characteristics.