Knee arthrography. Evolution and current status.

This article explores arthrography of the knee beginning with a brief historical perspective of conventional knee arthrography and culminating in direct and indirect MR arthrography of the knee. This article discusses the advantages of MR arthrography in the radiologic assessment of the postoperative meniscus, abnormalities of articular cartilage, and synovial-based processes.

Fixation with bioabsorbable pins in chevron bunionectomy.

Fixation with bioabsorbable pins in distal chevron bunionectomy reduces the inconvenience and the risk of infection associated with fixation with stainless-steel Kirschner wires, which leaves a portion of the wires protruding from the skin. However, use of bioabsorbable implants has been reported to be associated with osteolysis and formation of a sinus with a sterile discharge. We studied the outcome and complications seen with use of poly-p-dioxanone pins and those seen with use of stainless-steel Kirschner wires after chevron bunionectomy in 114 patients (144 feet). We found no difference between the treatment groups with regard to the prevalence of complications or the stability of fixation. Notably, the prevalence of osteolysis was quite similar between the treatment groups; none of the feet that had had fixation with bioabsorbable pins had formation of a sinus with a sterile discharge. We believe that bioabsorbable pins can be used reliably to fix the site of the osteotomy for a distal chevron bunionectomy without undue risk of osteolysis or other complications.

Role of magnetic resonance imaging in assessing factors affecting healing in scaphoid nonunions.

This study evaluates the role of magnetic resonance imaging in assessing the factors affecting the rate and healing time in scaphoid nonunions after surgery. Nineteen patients were assessed before surgery by radiographs, tomography, and magnetic resonance imaging. Fifteen had viable bone marrow and 4 patients had nonviable bone marrow on magnetic resonance imaging. All patients with normal preoperative magnetic resonance imaging healed in an average time of 4.7 months. Of the 4 patients with abnormal magnetic resonance imaging, but normal plain radiographs, 2 went on to heal in 10.5 months. The remaining 2 patients with abnormal magnetic resonance imaging and abnormal plain radiographs did not heal by 24 months. This study suggests 3 groups of scaphoid nonunions. Group 1 has normal trabecular bone radiographically and vascular bone marrow on magnetic resonance imaging and should be expected to heal after surgery. Group 2 has normal trabecular bone radiographically but avascular marrow on magnetic resonance imaging and may be expected to eventually heal after surgery. Group 3 has abnormal radiographs suggestive of fibrous replacement of the scaphoid proximal pole by the presence of cystic changes and the loss of trabecular bone, and avascular bone, as shown on magnetic resonance imaging. This study failed to show healing in this group of patients. Magnetic resonance imaging may be of benefit in predicting the healing potential in patients presenting with scaphoid nonunion.

Intermediate-term experience of Pipkin fracture-dislocations of the hip.

The purpose of this study was to review our intermediate-term experience with posterior fracture-dislocations of the hip. We evaluated the accuracy of the Pipkin and Brumback classification schemes as predictors of outcome, assessed the importance of certain treatment variables, and determined the complication rates of this injury in a group of 33 patients followed for an average of 49 months. The overall results were 67% good, 18% fair, and 15% poor, with no excellent results. The Pipkin classification scheme was a useful predictor of outcome because patients with less severe Pipkin 1 or 2 injuries had statistically significant better outcomes than did those who sustained Pipkin 3 or 4 injuries (p < 0.02). Due to a large number of subgroups, we could not demonstrate the usefulness of the Brumback classification system as a predictor of outcome. There were no statistically significant differences in outcome or complication rates when comparing time with hip reduction, definitive operative intervention, or anatomic operative approach to injury. Our study represents the second largest report on posterior dislocation of the hip associated with femoral head fracture. Although outcome of the patients in our series is not outstanding, the 67% good results represent a significant improvement over all previous reports with large numbers of patients. We demonstrate significant improvement in prognosis when treatment goals for these injuries include anatomic reduction, restoration of hip joint stability, and removal of all interposed bone fragments.

Lumbar epidural varix as a cause of radiculopathy.

STUDY DESIGN: Venous outflow obstruction or congestion has been implicated in the etiology of some lumbar radicular syndromes. Ten cases of epidural varices or variants manifesting themselves as masses within the lumbar spinal canal or adjacent foramina have been seen. OBJECTIVES: Diagnosis was made by multiplanar cross-sectional magnetic resonance and computed tomography imaging and confirmed in five patients by operative findings. These venous abnormalities differ from cases of arteriovenous malformations described in the literature. METHOD: Surgical treatment consisting of coagulative oblation and/or excision of the lesion was consistently successful in the five patients who underwent operations for recalcitrant symptoms. The other five patients experienced spontaneous resolution of symptoms. Three distinctly different types of these abnormalities have been identified. RESULTS: The described entity may account for some previously unexplained or spontaneously resolving cases of lumbar radiculitis. CONCLUSIONS: Knowledge of the existence of this condition, its possible etiologies, and its imaging characteristics may assist in its recognition and improved management of patients with it.

CT and MR evaluation of the labral capsular ligamentous complex of the shoulder.

Stability of the glenohumeral articulation is dependent on the integrity of the rotator cuff, labrum, glenohumeral ligaments, capsular elements, and bony glenoid. The importance of the soft-tissue elements in maintaining stability has been well documented in the surgical literature but has only recently been introduced into the radiologic literature. The purpose of this essay is to illustrate the normal labrum, capsular complex, and glenohumeral ligaments, including common congenital variations as depicted by CT arthrography and MR imaging, and to describe the pathologic findings leading to shoulder instability.

Magnetic resonance imaging of acute symptomatic Schmorl's node formation.

The intraspongious herniation of intervertebral disk material into the endplate of a vertebral body was first described by Schmorl in 1927. Any process which weakens the cartilaginous endplate or the subchondral cancellous bone may predispose to the development of Schmorl's nodes. These include Scheuermann's disease, infection, metabolic disorders, neoplastic disorders, and degenerative disease. In the young individual, however, trauma may precipitate an acute focal and symptomatic endplate herniation by the well-hydrated and delineated nucleus pulposus. Magnetic resonance imaging (MRI) is the most sensitive imaging method for the detection of intervertebral disk disease and, thus, has facilitated the diagnosis of traumatic Schmorl's nodes. MRI was very helpful in diagnosing an acute, traumatic, symptomatic Schmorl's node when plain film radiographs and nuclear medicine bone scan were unremarkable.

Hemothorax--an unusual presentation of spinal fracture in ankylosing spondylitis.

Patients with ankylosing spondylitis are susceptible to spinal fractures. In many cases there is no history of associated trauma or only minor trauma. The instability of such fractures and complicating neurologic sequelae are well documented. We describe an unusual complication of ankylosing spondylitis, hemothorax secondary to spinal fracture, that to our knowledge has not been previously reported. Further, we reemphasize that the instability of such fractures may lead to significant paravertebral soft tissue and vascular injuries.

Fracture of the occipital condyle: case report and review of the literature.

Fracture of the occipital condyle is a rare injury. We report a patient with an occipital condyle fracture who presented with negative plain films and a cranial nerve palsy. Diagnosis was established with high-resolution computed tomography. This fracture should be considered in a trauma patient with neck pain, negative plain cervical spine radiographs, and a cranial nerve palsy.