Sex Difference in Contusion of the Medial Femoral Condyle Rim-Association with MRI Occult Meniscal Tears in the ACL Deficient Knee.

Background: Meniscal tears, specifically lateral meniscal tears, have a larger than expected un-derdiagnosis rate in the presence of an ACL tear. The purpose of our study was to search for an MRI bone contusion pattern associated with MRI occult meniscal tears in patients with an ACL tear, specifically a contusion of the rim of the medial femoral condyle (RMFC). Our hypothesis was that there would be a significant association between RMFC contusions and MRI occult meniscal tears in patients with an ACL tear. We also searched for a difference between sexes with respect to the presence of the RMFC contusion in the setting of an occult meniscal tear. We also categorized the type, size, and location of these occult meniscal tears in the setting of an ACL tear. Methods: This was a retrospective study that examined characteristics of occult meniscal tears and their association with a RMFC bone contusion. IRB approval was obtained. The date range of the study was June 2009 through December 2015. 6392 consecutive knee MRI reports in patients with an ACL deficient knee were reviewed. The study group included 22 patients with MRI occult meniscal tears, the control group included 110 patients. Relevant statistical values were calculated. Results: The most common type of occult meniscal tears were small radial and small longitudinal tears of the lateral meniscus. Occult meniscal tears were associated with an RMFC contusion in the study group (p=0.0457), particularly in males (p = 0.0003). In males with a torn ACL, the sensitivity of an RMFC contusion for an occult meniscal tear was 80%. Conclusion: In males with an ACL tear, there was a significant association between a contusion of the RMFC and an occult meniscal tear (commonly small radial or small peripheral partial-thickness longitudinal tears). RMFC contusions were reliably identified by radiologists in this study.Level of Evidence: II.

Trauma in CT: The Role of Severe Injury on Satisfaction of Search Revised.

PURPOSE: The satisfaction-of-search (SOS) effect occurs when an abnormality on an image is missed because another is found. The aim of this experiment was to test whether severe distracting fractures control the magnitude of SOS on other fractures when both appear in a single CT image. METHODS: The institutional review board approved this study. The experimental (SOS) condition included 35 cervical spine CT cases, all of which contained severe cervical spine injuries. For each of these cases, a similar case was found that had no injuries. Image modification software was developed to add simulated fractures to each pair of cases, with and without a major injury. Sixteen different minor fractures were added to 16 of the 35 pairs of images. The 35 cases without native injuries constituted a control (non-SOS) condition mixed in a random order. Twenty radiologists read 35 mixed cases in each of two sessions. False-positive evaluations were collected only for cases without simulated fractures. RESULTS: An SOS effect on the detection of simulated fractures was not observed. There was a nonsignificant (P = .07) finding of poorer detection in the presence of cases with severe injuries. However, the magnitude of the effect was no greater than has been observed for less severe distracting injuries. CONCLUSIONS: The outcome agrees with the results of two previous experiments that failed to yield an SOS effect associated with detecting severe injuries, suggesting that the severity of a distracting injury does not determine whether a second injury is discovered.

Hand osteolysis in patients with adult T-cell leukemia-lymphoma: radiographic characteristics.

Adult T-cell leukemia-lymphoma (ATLL) is caused by human T-cell lymphotrophic virus I (HTLV-I) infection. Among ATLL cases, 70% of patients present with leukemia and the remaining patients present with lymphoma. Hand osteolysis in the patients with ATLL is considered as paraneoplastic syndrome and caused by parathyroid hormone-related peptide (PTHrP) released from tumor cells. Radiographic features are similar to hyperparathyroidism, but the distribution of osteolysis in hands appears to be slightly different with the authors' experiences. The objective of this study was to identify radiographic characteristics of hand osteolysis associated with ATLL. We included six ATLL patients (5 men and 1 woman; age range, 45-71 years). All the patients presented with acute leukemia, and three were associated with hypercalcemia and pain in various locations including hands. Patterns of osteolysis on hand radiographs were evaluated and recorded independently by three musculoskeletal radiologists. We analyzed the distribution of the bone resorption in the ray distribution of the hand, finger predilection, and the difference between the ulnar and radial sides. The bone resorption was characterized by frequent involvement of the distal and proximal phalanges, predilection of ring fingers and prominent involvement on the ulnar side, compared with frequent involvement of proximal and middle phalanges, index and middle fingers, and on the radial side in the bone resorption of typical hyperparathyroidism. Such distribution may be a characteristic feature of hand osteolysis in patients with ATLL. The present findings are helpful for physicians to differentiate PTHrP-mediated osteolysis in ATLL from parathyroid hormone-mediated hyperparathyroidism.

Effect of a Realigning Brace on Tibiofemoral Contact Stress.

OBJECTIVE: To determine the degree to which focally elevated tibiofemoral joint contact stress is reduced by using a frontal plane realigning brace. METHODS: Fifteen volunteers (9 women) with unicompartmental tibiofemoral osteoarthritis underwent weight-bearing radiographic imaging at 15-20° and 5-10° of knee flexion with and without an UnloaderOne knee brace. Discrete element analysis was used to estimate compartment-specific contact stress distributions. Paired t-tests were used to assess the differences in mean contact stress and contact stress distributions, comparing the braced and unbraced conditions. RESULTS: The mean ± SD age was 56.1 ± 6.4 years and body mass index was 28.4 ± 4.5 kg/m(2). Twelve of 15 participants were fit with braces set to unload the medial compartment. For the 15-20° condition, the mean contact stress in the compartment of interest did not significantly change (0.08 ± 0.35 MPa; P = 0.410). Also at 5-10° flexion, the mean contact stress in the compartment of interest did not significantly change with use of the brace (0.24 ± 0.45 MPa; P = 0.175). CONCLUSION: This is the first study of the effects of a frontal plane realignment brace on in vivo articular contact stress in native human knees. Using the off-the-shelf brace tested, there were no changes in compartmental tibiofemoral contact stress distributions at either 15-20° or 5-10° of knee flexion, revealing no redistribution of contact stress away from the compartment of interest. These findings indicate that the brace that was studied was ineffective for redistributing tibiofemoral contact stress. Further research is necessary to determine whether double-upright or customized frontal plane braces are effective in redistributing compartmental articular contact stress.

Diagnostic accuracy of 3D color volume-rendered CT images for peroneal tendon dislocation in patients with acute calcaneal fractures.

BACKGROUND: Use of three-dimensional (3D) color volume-rendered (VR) images has been reported to be more time-efficient compared to that of cross-sectional computed tomography (CT) images for the diagnosis of peroneal tendon dislocation. However, the diagnostic performance of this technique has not been studied. PURPOSE: To test diagnostic accuracy of 3D color VR CT images of ankle for peroneal tendon dislocation in patients with acute calcaneal fractures. MATERIAL AND METHODS: The study consisted of 121 ankle CT studies from 105 consecutive patients (85 men, 20 women; mean age, 42 years; age range, 16-75 years) with acute calcaneal fractures. Peroneal tendon dislocation was diagnosed on multiplanar CT images by consensus of two experienced musculoskeletal radiologists, which served as the reference standard. Three other musculoskeletal radiologists independently reviewed 3D images alone on a workstation. The readers determined whether or not there was peroneal tendon dislocation using three degrees of certainty (definite, probable, and possible). Diagnostic performance of 3D images for peroneal tendon dislocation was evaluated by calculating the sensitivities, specificities, and area under the receiver-operating characteristic (ROC) curves. RESULTS: Forty-eight (40%) out of 121 studies showed peroneal tendon dislocation based on the expert readings using multiplanar reformatted images. Sensitivities/specificities of 3D images measured 0.92/0.81, 0.88/0.90, and 0.81/0.92 for three readers, respectively. The area under the proper binormal ROC curve based on all three readers (0.93, 0.94, and 0.92) measured 0.93 with a 95% confidence interval of 0.89-0.98. CONCLUSION: Diagnostic accuracy of 3D images is comparable to, but not as good as that of MPR images for the diagnosis of peroneal tendon dislocation in patients with acute calcaneal fractures.

Clinical role of radiography for thoracic spine fractures in daily practice in the MDCT era: a retrospective review of 255 trauma patients.

PURPOSE: To retrospectively assess the diagnostic efficacy of radiography in detecting vertebral body fractures of the thoracic spine compared with MDCT, to assess the confounding factors reducing the diagnostic efficacy, and to investigate the outcomes of radiographically overlooked patients. MATERIALS AND METHODS: Two hundred fifty-five patients suspected of thoracic spine fractures were enrolled. We assessed the diagnostic efficacy of radiography for the patients sub-grouped based on five confounding factors: chest abnormalities, head injuries, cervical spine fractures, upper extremity injuries, and age of 65 years or older. We investigated the outcomes of radiographically overlooked patients. RESULTS: Three hundred fifty-one vertebral body fractures were detected. The per-fracture sensitivities and specificities were 55 % and 94 % for vertebral body fractures and 41 and 99 % for unstable fractures. In patients with upper extremity injuries or aged 65 years or older, radiography was less sensitive in detecting the unstable fractures (P < 0.05). Nineteen patients were overlooked by radiography; two had neurological deficits and needed surgical fixation; 15 with no neurological deficit were conservatively treated with uneventful outcomes. CONCLUSION: Radiography had low sensitivity but high specificity. In daily practice, primary use of MDCT is beneficial for patients with neurological deficit or upper extremity injuries or elderly patients.

Satisfaction of search for subtle skeletal fractures may not be induced by more serious skeletal injury.

PURPOSE: The aim of this experiment was to test whether radiographs of major injuries, those having serious consequences for life and limb, produce a satisfaction-of-search (SOS) effect on the detection of subtle, nondisplaced test fractures. METHODS: Institutional review board approval and informed consent from 24 participants were obtained. Seventy simulated patients with multiple trauma injuries were constructed from radiographs of 3 different anatomic areas demonstrated only skeletal injuries. Readers evaluated each patient under 2 conditions: first, in the non-SOS condition, no injuries were present in the first anatomic images, and second, in the SOS condition, the first anatomic images included major injuries requiring immediate medical intervention. The SOS effect was measured on detection accuracy using receiver operating characteristic analysis for subtle test fractures presented on examinations of the second or third anatomic areas. RESULTS: Satisfaction-of-search reduction in receiver operating characteristic experiments for detecting subtle test fractures with the addition of a major injury was not observed. CONCLUSIONS: Satisfaction of search was absent when major injuries were presented on radiographs. This finding rejects the hypothesis that SOS arises primarily from injuries requiring major intervention. Similar results have been found previously when major injuries were presented on CT but test fractures were presented on radiographs. This new finding rejects the possibility that SOS is absent because added and test fractures appear on different imaging modalities.

Effects of concurrent use of an ankle support with a laterally wedged insole for medial knee osteoarthritis.

OBJECTIVE: To determine the biomechanical and symptomatic effects of concurrent use of an ankle support and a laterally wedged insole on adults with symptomatic medial compartment knee osteoarthritis. DESIGN: Randomized, crossover clinical trial. SETTING: Outpatient gait analysis laboratory. PARTICIPANTS: Fourteen adults, mean age 51.9 +/- 8.3 years, with symptomatic medial compartment knee osteoarthritis and no previous lower-limb surgeries or history of wedged insole use were recruited through a radiology database and phone screen. INTERVENTIONS: Subjects were randomized to use a laterally wedged insole before (n = 8) or after (n = 6) use of the insole with an ankle support for 2 weeks. MAIN OUTCOME MEASURES: Lower-limb alignment by radiographic hip-knee-ankle angle, talocalcaneal, and talar tilt angles; medial compartment loading by the external knee adduction moment; and pain by visual analog scale and the Knee Osteoarthritis Outcome Score pain subscale. RESULTS: There were no differences between groups for age, gender, body mass index, baseline knee pain, or alignment. Augmentation of the wedged insole with the ankle supporter did not result in any significant changes in lower-limb alignment or external knee adduction moment. Intergroup crossover comparisons demonstrated a 10.5-point greater average improvement in Knee Osteoarthritis Outcome Score pain subscale (P < .011) and a trend towards a 10.2-point improvement in the Activities of Daily Living subscale (P < .055) with the wedged insole alone in comparison with concurrent use of the ankle support with the wedged insole. CONCLUSION: Concurrent use of an ankle support did not appear to improve the effects of a laterally wedged insole on lower-limb mechanical alignment or medial compartment loading. Improved pain and activities of daily living with use of the wedged insole alone suggests that use of an ankle support may attenuate clinical benefit.

Musculoskeletal CT: recent advances and current clinical applications.

This article discusses the indications for CT in the management of acute fractures and postoperative complications related to orthopedic procedures. The current clinical use of CT in spine injuries, pelvic/acetabular fractures, and major fractures in the extremities is discussed. Multidetector CT techniques to minimize metal artifacts and common hardware complications are reviewed.

Satisfaction of search in multitrauma patients: severity of detected fractures.

RATIONALE AND OBJECTIVES: Satisfaction of search (SOS) occurs when an abnormality is missed because another abnormality has been detected. This research studied whether the severity of a detected fracture determines whether subsequent fractures are overlooked. MATERIALS AND METHODS: Each of 70 simulated multitrauma patients presented examinations of three anatomic areas. Readers evaluated each patient under two experimental conditions: when the images of the first anatomic area included a fracture (the SOS condition), and when it did not (the control condition). The SOS effect was measured on detection accuracy for subtle test fractures presented on examinations of the second and third anatomic areas. In an experiment with 12 radiology readers, the initial SOS radiographs showed nondisplaced fractures of extremities, fractures associated with low morbidity. In another experiment with 12 different radiology readers, the initial examination, usually a computed tomography scan, showed cervical and pelvic fractures of the type associated with high morbidity. Because of their more direct role in patient care, the experiment using high morbidity SOS fractures was repeated with 17 orthopedic readers. RESULTS: Detection of subtle test fractures was substantially reduced when fractures of low morbidity were added (P < .01). No similar SOS effect was observed in either experiment in which added fractures were associated with high morbidity. CONCLUSIONS: The satisfaction of search effect in skeletal radiology was replicated, essentially doubling the evidence for SOS in musculoskeletal radiology, and providing an essential contrast to the absence of SOS from high-morbidity fractures.

A single fracture in the ring of vertebrae below the atlas: report of four cases.

A single fracture of the ring of a vertebra is a rare injury of the spine. In this report, we present five single fractures of the posterior ring of the cervical spine below the atlas from four patients after motor vehicle accidents. Initial radiographs failed to show any of these fractures; all were detected by computed tomography. Single ring fractures are stable and none of our patients presented with a neurological deficit. Patients were treated conservatively with a cervical collar or a cervicothoracic brace. They all recovered without any neurological abnormalities.

A single fracture in the atlas ring: report of two cases and a review of the literature.

Atlas fractures commonly present more than two breaks in its ring structure because of the unique anatomy and the mechanism of injury. The incidence of a single break in the atlas ring is exceedingly rare. However, we encountered two cases of a single fracture of the atlas. One patient was struck by a falling tree on the right side of the head and the other was involved in a motor vehicle accident. Radiographs of the cervical spine failed to show a single fracture or other abnormalities. Computed tomography demonstrated the single fracture. The patients were treated conservatively with a cervical collar, and they both recovered completely. In this article, we present two cases of a single fracture of the atlas with a review of the literature.

Peroneal tendon subluxation and dislocation: detection on volume-rendered images--initial experience.

Institutional review board approval was received and informed consent was not required for this Health Insurance Portability and Accountability Act-compliant study. The purpose of this study was to retrospectively assess the time efficiency of three-dimensional volume-rendered images obtained from multi-detector row computed tomographic data for the diagnosis of peroneal tendon subluxation or dislocation by using the consensus interpretation of multiplanar reformatted (MPR) images as the reference standard. The reference standard was provided by two musculoskeletal radiologists, and two less experienced readers evaluated 37 images in 32 patients (24 men, eight women; mean age, 41 years; age range, 18-75 years) with acute calcaneal fractures. An analysis of variance was used to compare interpretation time, and the Wilcoxon signed rank test was used to analyze diagnostic difficulty. The average time required for diagnosis was significantly shorter with volume-rendered images than with MPR images (reader 1: 42 vs 78 seconds, P<.001; reader 2: 50 vs 69 seconds, P<.01).

Interobserver agreement for Letournel acetabular fracture classification with multidetector CT: are standard Judet radiographs necessary?

PURPOSE: To retrospectively evaluate interobserver agreement for Letournel acetabular fracture classification with radiography alone and multidetector computed tomography (CT) alone and to retrospectively assess whether standard Judet views lead to a change in the classification. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study, which included 101 imaging studies performed in 99 patients (78 male, 21 female; mean age, 43 years; age range, 15-86 years) with acetabular fractures. Two musculoskeletal radiologists independently classified the fractures with radiography alone and multidetector CT alone. Multiplanar reformatted and three-dimensional (3D) CT images were reviewed at a computer workstation. Readers were shown radiographs at the end of multidetector CT image reading to see if this would change the multidetector CT-based classification. kappa Values were calculated to assess interobserver agreement. For surgically treated patients, the McNemar test was used to compare the accuracy of readers' classifications. The reference standard was a combination of preoperative radiographic and multidetector CT image findings and intraoperative findings. RESULTS: Interobserver agreement was moderate (kappa = 0.42) with radiography and substantial (kappa = 0.70) with multidetector CT. Multidetector CT classification was changed in two cases (one case for each reader) after standard Judet views were added. In 73 surgically treated patients, agreement with the surgeons' classification was higher with multidetector CT than with radiography (P < .01 for one reader, P = .06 for the other reader). CONCLUSION: There is substantial interobserver agreement for Letournel acetabular fracture classification with multiplanar reformatted and 3D multidetector CT images. Standard Judet pelvic radiographs add little information for changing the multidetector CT classification.

Orthopedic hardware complications diagnosed with multi-detector row CT.

PURPOSE: To retrospectively evaluate multi-detector row computed tomography (CT) for the depiction of orthopedic hardware complications in the spine and appendicular skeleton. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval; patient informed consent was not required. Results of 114 multi-detector row CT studies performed because of possible hardware complications in 109 patients (57 men, 52 women; mean age, 44 years; age range, 12-82 years) were available for analysis. The CT studies were retrospectively reviewed and compared with clinical or surgical outcomes, which were used as the reference standard. In another experiment, detection of hardware complications on radiographs and multi-detector row CT images was compared between two readers for selected cases (18 positive and 26 negative) by using receiver operating characteristic (ROC) methods. RESULTS: For 91 (80%) of 114 multi-detector row CT studies, the complication status could be determined on the basis of clinical or surgical outcomes. Twenty-three multi-detector row CT studies were confirmed to be positive (revealing 10 cases of nonunion, five cases of hardware malplacement, three cases of hardware loosening, three perihardware fractures, and two chronic infections), and 57 were confirmed to be negative. There were three false-positive and eight false-negative multi-detector row CT studies. With clinical or surgical outcomes as the reference standard, the sensitivity, specificity, and positive and negative predictive values of multi-detector row CT were 74% (23 of 31 studies), 95% (57 of 60 studies), 88% (23 of 26 studies), and 88% (57 of 65 studies), respectively. Results of ROC analysis indicated that detection of hardware complications was much lower with radiography than with multi-detector row CT (area under ROC curve, 0.84 vs 1.00; F = 4.69, df = 1, 43; P < .05). CONCLUSION: Multi-detector row CT is an effective tool for depicting orthopedic hardware complications.

Patellar fractures after total knee replacement.

OBJECTIVE: The objective of our study was to describe the patterns of patellar fracture after total knee replacement and assess their clinical significance. MATERIALS AND METHODS: A retrospective review of patellar fractures after total knee replacement was performed. Seventeen cases were identified over a 10-year period. Radiographs, radiology reports, medical records, and operative notes were reviewed and analyzed. The clinical analysis included the time to fracture, the patient's symptoms and signs, whether the extensor mechanism was disrupted, and the treatment administered for the fracture. The radiographic analysis included fracture pattern, displacement, patellar position, presence of patellar osteonecrosis, and presence of soft-tissue abnormality. RESULTS: The incidence of patellar fractures after total knee replacement was 1.14%. The mean time from total knee replacement to patellar fracture was 17.5 months. Nine fractures were asymptomatic and identified on routine follow-up radiographs. The patterns of fracture were diverse: Transverse (n = 6), comminuted (n = 2), vertical (n = 5), and avulsion (n =4) fractures were seen. Thirteen fractures were displaced. Patellar osteonecrosis was suspected in four fractures, and three fractures were associated with disruption of the quadriceps tendons. Thirteen fractures were treated nonoperatively, and four were treated surgically. CONCLUSION: Patellar fractures are an uncommon, but important, complication after total knee replacement. Radiologists should be familiar with the imaging features of these fractures and their clinical significance.

Acute traumatic spinal epidural hematoma: imaging and neurologic outcome.

The purpose of this study was to present MRI characteristics of traumatic spinal epidural hematomas (TSEHs) and to evaluate their effect on neurologic outcome. A retrospective analysis was performed of all 74 cases in which patients underwent emergent spinal MRI in the setting of acute trauma at our institution's Emergency Department between June 2002 and January 2003. MRI studies were evaluated for the presence of a TSEH. CT studies were evaluated for the presence of osseous trauma. Patient data were collected from medical records on the initial neurologic status at admission and at 6 months after injury. Twenty-seven of 74 patients had a spinal fracture and a TSEH. Twenty-five of 74 patients had a spinal fracture with no TSEH. Twenty-two of 74 patients had normal imaging studies. Six-month follow-up of neurologic status demonstrated no statistically significant difference in neurologic outcome between patients with spinal fractures and TSEH and those with spinal fractures but no TSEH. If a spinal fracture and abnormal neurologic exam are present, the neurologic outcome at 6 months is not worsened by the presence of a TSEH.

Ball-thrower's fracture of the humerus.

A relatively rare case of ball-thrower's fracture of the humerus is presented. Severe muscular action is an uncommon cause of humeral fractures but has been well documented in the orthopedic literature. To our knowledge, this fracture has not been described in the radiology literature, and awareness of this entity could preclude further unnecessary workup. The mechanism of injury and its typical radiographic appearance is described.

Spondyloarthropathies: ankylosing spondylitis and psoriatic arthritis.

As advances in the treatment of ankylosing spondylitis continue, TNF-alpha blocking agents may eventually be used as a first-line treatment. MR imaging could then be used to aid in the early diagnosis of ankylosing spondylitis by identifying early sacroiliitis, followed by immediate initiation of treatment to prevent the progression of the disease with its accompanying morbidities. Currently, radiographic identification of sacroiliitis remains the mainstay in diagnosing ankylosing spondylitis. In ankylosing spondylitis and psoriasis, MR imaging can demonstrate areas that are undergoing active inflammatory changes and enthesitis, aiding in the diagnosis of a spondyloarthropathy.