Bone bruise vs. non-displaced fracture on MRI: a novel grading system for predicting return-to-play.

OBJECTIVE: To devise an MRI grading scheme for osseous contusion patterns in elite hockey players for predicting return-to-play (RTP). METHODS: A retrospective review was performed to identify traumatic lower extremity osseous injuries in professional hockey players. A total of 28 injuries (17 players) were identified over a 10-year period. All had MRIs acquired at ≥ 1.5 T within a mean interval of 2 days from initial injury. MRIs were retrospectively reviewed by 3 musculoskeletal radiologists for osseous contusion pattern, classified as grade 1 (mild), 2 (moderate), or 3 (severe). Grade 3 contusions were further subdivided by the presence or absence of fracture, defined as discrete cortical disruption on MRI or follow-up CT. RTP was calculated from date of injury to next game played based on game log data. Statistical analysis was performed using ANOVA and post hoc unpaired t test. RESULTS: Mean RTP for grade 1, 2, and 3 injuries was 2.8, 4.5, and 20.3 days, respectively. Grade 3 injuries without and with cortical fractures had mean RTP of 18.3 and 21.4 days, respectively. ANOVA analysis between groups achieved statistical significance (p < 0.001). Post hoc t test demonstrated statistically significant differences between grade 3 and grades 1 (p < 0.001) and 2 (p < 0.001) injuries. There was no statistical difference in RTP between grade 3 subgroups without and with fracture (p = 0.327). CONCLUSION: We propose a novel MRI grading system for assessing severity of osseous contusions and predicting RTP. Clinically, there was no statistically significant difference in RTP between severe osseous contusions and nondisplaced fractures in elite hockey players.

Extensor carpi ulnaris tendon pathology and ulnar styloid bone marrow edema as diagnostic markers of peripheral triangular fibrocartilage complex tears on wrist MRI: a case-control study.

OBJECTIVES: To evaluate extensor carpi ulnaris (ECU) tendon pathology and ulnar styloid process bone marrow edema (BME) as diagnostic MRI markers for peripheral triangular fibrocartilage complex (TFCC) tears. METHODS: One hundred thirty-three patients (age range 21-75, 68 females) with wrist 1.5-T MRI and arthroscopy were included in this retrospective case-control study. The presence of TFCC tears (no tear, central perforation, or peripheral tear), ECU pathology (tenosynovitis, tendinosis, tear or subluxation), and BME at the ulnar styloid process were determined on MRI and correlated with arthroscopy. Cross-tabulation with chi-square tests, binary logistic regression with odds ratios (OR), and sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were used to describe diagnostic efficacy. RESULTS: On arthroscopy, 46 cases with no TFCC tear, 34 cases with central perforations, and 53 cases with peripheral TFCC tears were identified. ECU pathology was seen in 19.6% (9/46) of patients with no TFCC tears, in 11.8% (4/34) with central perforations and in 84.9% (45/53) with peripheral TFCC tears (p < 0.001); the respective numbers for BME were 21.7% (10/46), 23.5% (8/34), and 88.7% (47/53) (p < 0.001). Binary regression analysis showed additional value from ECU pathology and BME in predicting peripheral TFCC tears. The combined approach with direct MRI evaluation and both ECU pathology and BME yielded a 100% positive predictive value for peripheral TFCC tear as compared to 89% with direct evaluation alone. CONCLUSIONS: ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to diagnose tears. KEY POINTS: • ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to confirm the presence of TFCC tears. • If there is a peripheral TFCC tear on direct MRI evaluation and in addition both ECU pathology and BME on MRI, the positive predictive value is 100% that there will be a tear on arthroscopy compared to 89% with direct evaluation alone. • If there is no peripheral TFCC tear on direct evaluation and neither ECU pathology nor BME on MRI, the negative predictive value is 98% that there will be no tear on arthroscopy compared to 94% with direct evaluation alone.

Presurgical Perspectives and Post-treatment Evaluation of Achilles Tendon Injuries.

The Achilles is a commonly injured tendon, prone to degeneration and tear. Achilles tendon treatment ranges from conservative management to injections, tenotomy, open versus percutaneous tendon repair, graft reconstruction, and flexor hallucis longus transfer. Interpreting postoperative imaging of the Achilles tendon is a difficult task for many providers. This article clarifies these issues by presenting the imaging findings following standard treatments and depicts expected appearance versus recurrent tear and other complications.

Imaging the Postoperative Elbow.

Evaluation of postoperative images of any joint can be a daunting task, and the elbow is no exception. Patients may be imaged with a complication of the repair, or the postoperative changes may be incidentally observed as the patient is imaged for other reasons. We divide the postoperative elbow into soft tissue procedures (covering ligament and tendon repairs, as well as compartmental release and nerve transposition), joint-related procedures (osteochondral lesion treatment, ostectomy, and joint replacement), and bone procedures (fracture fixation). We summarize the procedures and their indications, show normal imaging appearances, and finally cover common complications.

Shear wave elastography assessment and comparison study of the Achilles tendons in optimally conditioned asymptomatic young collegiate athletes.

OBJECTIVE: To assess the functional parameters of the Achilles tendons among asymptomatic college level athletes using shear wave elastography (SWE) and to describe the relationship to athlete demographics and anthropometric lower extremity measurements. MATERIAL AND METHODS: Sixty-five athletes were included in this IRB-approved study. SWE measurements were made on two tendon positions (neutral state and active maximum dorsiflexion) with two different probe orientations (longitudinal and transverse). Associations were assessed with BMI, tibial/foot length, type of sports, and resting/maximal dorsiflexion-plantar flexion angles. RESULTS: Thirty-five (53.8%) males and 30 (46.2%) females with an overall mean age of 20.9 years (± 2.8), mean height of 176 cm (± 0.11), and mean weight of 74.1 kg (± 12) were studied. In the neutral state, the mean wave velocity of 7.5 m sec-1 and the mean elastic modulus of 176.8 kPa were recorded. In active maximum dorsiflexion, the mean velocity was 8.3 m sec-1 and mean elastic modulus was 199 kPa. On the transverse view, the mean velocity and elastic measurements were significantly lower (p = 0.0001). No significant differences in SWE parameters were seen between male and female athletes regardless of probe orientation (p < 0.05) with SWE values being higher in the running group vs non-running group (p < 0.05). In neutral state, longitudinal SWE measurements correlated with the tibia-foot length whereas transverse measurements correlated with the tendon diameter and ankle resting angle (ARA) (p < 0.005). CONCLUSION: SWE can distinguish functional differences in Achilles tendon stiffness between athletes engaged in running-intensive sports compared with other athletes.

MRI nomenclature for musculoskeletal infection.

The Society of Skeletal Radiology (SSR) Practice Guidelines and Technical Standards Committee identified musculoskeletal infection as a White Paper topic, and selected a Committee, tasked with developing a consensus on nomenclature for MRI of musculoskeletal infection outside the spine. The objective of the White Paper was to critically assess the literature and propose standardized terminology for imaging findings of infection on MRI, in order to improve both communication with clinical colleagues and patient care.A definition was proposed for each term; debate followed, and the committee reached consensus. Potential controversies were raised, with formulated recommendations. The committee arrived at consensus definitions for cellulitis, soft tissue abscess, and necrotizing infection, while discouraging the nonspecific term phlegmon. For bone infection, the term osteitis is not useful; the panel recommends using terms that describe the likelihood of osteomyelitis in cases where definitive signal changes are lacking. The work was presented virtually to SSR members, who had the opportunity for review and modification prior to submission for publication.

Extensive multifocal emphysematous osteomyelitis: fatal outcome in a patient with psychiatric history.

Emphysematous osteomyelitis is a rare entity with potentially devastating consequences, even after prompt and aggressive intervention. It is characterized by intraosseous gas and may be complicated by adjacent abscess formation. There are a handful of previously reported cases of emphysematous osteomyelitis, but none to the degree as reported here. Specifically, we report an extremely rare case of extensive multifocal emphysematous osteomyelitis involving both the axial and appendicular skeleton in a 20-year-old woman.

Talus Partitus: a review of five cases diagnosed by MRI.

Talus partitus is a rare skeletal developmental abnormality characterized by a split of the posterior talar bone in the coronal plane. Patients with talus partitus typically present with posterior ankle pain and instability, often displaying varying degrees of chondrosis and secondary degenerative change on imaging. To date, only few case reports describing the imaging appearance of talus partitus have been published. The majority of these publications are limited to radiographic and computed tomography (CT) imaging findings, despite the ubiquity of magnetic resonance imaging (MRI). To the authors' knowledge, there is little description of typical MRI findings of the symptomatic talus partitus in the radiologic literature. We present a series of five cases of talus partitus identified on MRI and examine pitfalls in diagnosis, differential considerations, pathophysiology, and treatment options.

Predicting osteomyelitis in patients whose initial MRI demonstrated bone marrow edema without corresponding T1 signal marrow replacement.

PURPOSE: We endeavored to determine which characteristics of diabetic ulcers portend the strongest risk for osteomyelitis in patients whose initial T1-weighted imaging was normal. By determining which features have a greater risk for osteomyelitis, clinicians can treat patients more aggressively to reduce the sequela of inadequately treated osteomyelitis. MATERIALS AND METHODS: We performed a retrospective analysis of MR imaging from 60 pedal ulcers with suspected osteomyelitis. Ulcer dimensions and depth were measured. Ratios of marrow ROI/joint fluid ROI on T2/STIR sequences were obtained. Progression to osteomyelitis on subsequent MRI was characterized by loss of normal marrow signal on T1-weighted images. Statistical analysis was performed with a two-sample t test and Cox proportional hazard model. A p value < 0.05 was used as the threshold for statistical significance. RESULTS: Sixty MR exams were identified. Thirty-four progressed to osteomyelitis. Marrow ROI/joint fluid ratios averaged 65% in the osteomyelitis group, and 45% in the non-osteomyelitis group, p < 0.001. ROI ratios > 53% had a 6.5-fold increased risk of osteomyelitis, p < 0.001. Proximity to bone averaged 6 mm in the osteomyelitis group and 9 mm in the non-osteomyelitis group, p = 0.02. Ulcer size averaged 4 cm2 in the osteomyelitis group versus 2.4 cm2 in the non-osteomyelitis group, p = 0.07. Ulcers greater than 3 cm2 has a 2-fold increase in the risk of osteomyelitis, p = 0.04. CONCLUSION: Increasing bone marrow ROI signal/joint fluid ratios on T2/STIR images were the strongest risk factors for developing osteomyelitis, while ulcer size and depth are weaker predictors.

Painful type II os naviculare: introduction of a standardized, reproducible classification system.

OBJECTIVE: To provide a novel MRI classification system for the symptomatic type II os naviculare by creating a standardized grading of associated bone marrow edema (BME) and correlating with patient symptoms. METHODS: BME was classified on an ordinal scale: grade 1, faint signal immediately adjacent to the synchondrosis; grade 2, intermediate signal within the os and navicular tuberosity without extending to the navicular body; grade 3, intense signal extending to the navicular body. BME on 59 MRIs was independently graded by three radiologists. Inter- and intra-observer agreement was analyzed using intraclass correlation coefficient. Univariate and multivariate analyses assessed for patient and imaging characteristics predictive of subjective pain score. A cohort of 82 patients without BME represented a control group. RESULTS: Inter-observer agreement of BME grade was 0.95 (CI 0.93-0.97) and intra-observer was 0.92 (CI 0.87-0.96), indicating excellent agreement. In patients with BME, predictors of more severe pain were longer duration of pain (p = 0.02) and presence of soft tissue edema overlying the os naviculare (p < 0.001). One hundred percent of subjects with BME localized their pain to the medial midfoot (59/59) versus 25.6% (21/82) of controls (p < 0.001). CONCLUSIONS: This novel grading system provides reliable quantification of BME associated with os naviculare, which is a specific cause of medial foot/ankle pain. Early diagnosis is important as pain severity worsens with longer duration of symptoms. Pain severity is correlated with soft tissue edema overlying the os, which may be secondary to extrinsic compression, reactive to biomechanical stress, or reflect direct trauma.

MRI of a painful carpal boss: variations at the extensor carpi radialis brevis insertion and imaging findings in regional traumatic and overuse injuries.

OBJECTIVE: To report patterns of MRI findings involving carpal boss and extensor carpi radialis brevis (ECRB) tendon insertion in individuals with overuse-related or post-traumatic wrist pain. MATERIALS AND METHODS: Eighty-four MRI cases with carpal bossing between December 2006 and June 2015 were analyzed by two fellowship-trained musculoskeletal radiologists. The following MRI findings were reviewed: type of carpal bossing (bony prominence, partial coalition, os styloideum), insertion of ECRB tendon (to the 3rd metacarpal, to carpal boss or to both), bone marrow edema (BME), insertion site, and tenosynovitis/tendinosis of ECRB tendon. Clinical information on wrist pain was available on 68 patients. RESULTS: Fused carpal bossing was detected in 21%, partial coalition in 35%, and os styloideum in 44% of the cases. Regional BME was observed in 64% of the cases. When BME specifically at the carpal boss was assessed, 78% of stable and 50% of unstable bosses showed BME (p = 0.035). ECRB tendon inserted on a carpal boss in 20%, on the 3rd metacarpal bone in 35%, and on both sites in 45% of the cases. As BME at the carpal boss was assessed, BME was detected at the respective insertion sites in 71%, 35%, and 66% of the cases (p = 0.015). Dorsal wrist pain was associated with BME as 75% of the patients had regional BME in the vicinity of the carpal boss (p = 0.006). CONCLUSION: A spectrum ranging from complete fusion of a boss to an entirely unfused os styloideum exists with a variable ECRB insertional anatomy. BME at the carpal boss is a consistent MRI finding.

Second opinions in orthopedic oncology imaging: can fellowship training reduce clinically significant discrepancies?

OBJECTIVE: To determine factors that lead to significant discrepancies in second-opinion consultation of orthopedic oncology patients, and particularly if musculoskeletal fellowship training can decrease clinically significant discrepancies. METHODS: A PACS database was queried for secondary reads on outside cross-sectional imaging studies, as requested by orthopedic oncology from 2014 to 2017. Comparison of original and secondary reports was performed using a published seven-point scale that defines clinically significant discrepancies. An online search was performed for each original radiologist to record if a fellowship in musculoskeletal imaging was completed. Additionally, years of post-residency experience, number of Medicare part B patients billed per year (marker of practice volume), and average hierarchical condition category for each radiologist (marker of practice complexity) was recorded. RESULTS: A total of 571 patients met the inclusion criteria, with 184 cases initially interpreted by an outside fellowship trained musculoskeletal (MSK) radiologist and 387 cases initially interpreted by a non-MSK trained radiologist. The rate of clinically significant discrepancy was 9.2% when initially interpreted by MSK radiologists compared with 27.9% when initially performed by non-MSK radiologists (p < 0.05). After adjustment by both patient characteristics and radiologist characteristics, the likelihood of clinically significant discrepancies was greater for initial interpretations by non-MSK radiologists compared with MSK radiologists (OR = 1.36; 95% CI = 1.23-2.49). CONCLUSION: In orthopedic oncology patients, the rate of clinically significant discrepancies was significantly higher when initially interpreted by non-MSK radiologists compared with MSK radiologists. The lower rate of clinically significant discrepancies demonstrates that subspecialty training may direct more appropriate diagnosis and treatment.

Lumbosacral transitional vertebrae: significance of local bone marrow edema at the transverse processes.

OBJECTIVE: To evaluate the association between low back pain and bone marrow edema in lumbosacral transitional vertebra (LSTV) transverse processes, and to assess the prevalence of LSTV in a physically active population. MATERIALS AND METHODS: Individuals with LSTV on coronal MRI studies were identified in a retrospective review by keyword search from PACS. In total, 140 cases were reviewed by two fellowship-trained musculoskeletal radiologists. Data on associated low back pain were collected from patient records at the time of the imaging. RESULTS: Bone marrow edema was observed in 44% of the cases, but no correlation with low back pain was found. On coronal MRI, the prevalence of LSTV was 2.6%, with type II LSTV being the most common subtype. CONCLUSIONS: No correlation with bone marrow edema at the transverse processes of the LSTV and low back pain was observed. In our selected study population, the prevalence of LSTV was low.

Potential Utility of a Combined Approach with US and MR Arthrography to Image Medial Elbow Pain in Baseball Players.

Purpose To evaluate a combined imaging approach with both ultrasonography (US; conventional US and valgus stress US) and magnetic resonance (MR) arthrography in baseball players with medial elbow pain. Materials and Methods Institutional review board approval was obtained and the requirement for informed consent was waived. The study is compliant with HIPAA. Baseball players with medial elbow pain underwent US in addition to MR arthrography. Findings were assessed with each modality alone and both combined in this retrospective investigation. For the evaluation of ulnar collateral ligament (UCL) tears with stress US, the interval gapping of the medial elbow joint was measured between rest and valgus stress both at the injured and at the uninjured (contralateral) elbow. Surgical or arthroscopic correlation was available as the so-called gold standard. McNemar tests compared the accuracies of the imaging modalities. Results In this study, 144 baseball players had 191 findings of medial elbow pain, including 53 UCL tears. With stress US, joint gapping at the injured elbow greater than 1.0 mm compared with the contralateral elbow yielded a sensitivity, specificity, and accuracy of 96%, 81%, and 87%, respectively, for diagnosing UCL tears. With MR arthrography, the sensitivity, specificity, and accuracy for UCL tears were 81%, 91%, and 88%, respectively, and increased to 96% (P = .013, McNemar test), 99% (P = .023), and 98% (P < .001), respectively, when combined with US to a dual modality MR and US approach. For 31 patients with ulnar neuritis, the sensitivity, specificity, and accuracy increased from 74%, 92%, and 88%, respectively, with MR arthrography alone to 90% (P = .07, McNemar test), 100% (P < .001), and 98% (P < .001) combined with US. For the 59 myotendinous and the 48 osteochondral diagnoses, the sensitivity, specificity, and accuracy with MR arthrography alone were 93%, 93%, and 93%, and 94%, 98%, and 97%, respectively, with no additional diagnostic value from US. Conclusion The combined approach with both MR arthrography and US shows higher accuracy than each modality alone for the assessment of medial elbow pain. (©) RSNA, 2016.

Sports Injuries about the Hip: What the Radiologist Should Know.

Injuries of the hip and surrounding structures represent a complex and commonly encountered scenario in athletes, with improper diagnosis serving as a cause of delayed return to play or progression to a more serious injury. As such, radiologists play an essential role in guiding management of athletic injuries. Familiarity with hip anatomy and the advantages and limitations of various imaging modalities is of paramount importance for accurate and timely diagnosis. Magnetic resonance (MR) imaging is often the modality of choice for evaluating many of the injuries discussed, although preliminary evaluation with conventional radiography and use of other imaging modalities such as ultrasonography (US), computed tomography, and bone scintigraphy may be supplementary or preferred in certain situations. Stress fractures, thigh splints, and posterior hip dislocations are important structural injuries to consider in the athlete, initially imaged with radiographs and often best diagnosed with MR imaging. Apophyseal injuries are particularly important to consider in young athletes and may be acute or related to chronic repetitive microtrauma. Femoroacetabular impingement has been implicated in development of labral tears and cartilage abnormalities. Tear of the ligamentum teres is now recognized as a potential cause of hip pain and instability, best evaluated with MR arthrography. Greater trochanteric pain syndrome encompasses a group of conditions leading to lateral hip pain, with US playing an increasingly important role for both evaluation and image-guided treatment. Muscle injuries and athletic pubalgia are common in athletes. Lastly, snapping hip syndrome and Morel-Lavallée lesions are two less common but nonetheless important considerations. ©RSNA, 2016.

Association of Gluteus Medius and Minimus Muscle Atrophy and Fall-Related Hip Fracture in Older Individuals Using Computed Tomography.

PURPOSE: The aim of this study was to determine an association between fall-related hip and/or pelvic fractures and gluteus medius and minimus atrophy. METHODS: Retrospective review of 64 patients with fall-related hip/pelvic fractures and 96 age- and sex-stratified controls was performed. Gluteus medius, gluteus minimus, tensor fascia lata, and iliopsoas atrophy was scored using a standard scale. Statistical analysis was performed. RESULTS: There is a significant difference (P < 0.0001) in gluteus medius and minimus atrophy in the fracture versus control groups. Presence of gluteus atrophy was predictive of fall-related fracture (odds ratio, 2.15; 95% confidence interval, 1.08-4.31). There is no significant difference in tensor fascia lata (P = 0.47) or iliopsoas (P = 0.15) atrophy between the 2 groups. Gluteus atrophy increased with age (r = 0.41, P < 0.0001). In unilateral fractures, there is a significant difference (P = 0.0002) in ipsilateral versus contralateral gluteus medius atrophy. CONCLUSIONS: Gluteus medius and minimus muscle atrophy is greater in fall-related hip/pelvic fractures, which may predispose the elderly to falls.

Update: Imaging of Lower Extremity Infection.

Pedal infection is a difficult diagnostic problem for clinicians and radiologists alike, especially in patients with diabetes. Vascular and neuropathic disease complicates the clinical picture and imaging appearance. Radiographs are usually the first examination ordered, offering an excellent overview of previous surgery, structural deformities, and neuropathic joint disease. Ultrasound and computed tomography are occasionally useful to answer specific questions. Scintigraphy has become less popular because MRI provides high sensitivity and specificity as well as detailed anatomical information. Almost all diabetic foot infections originate from a foot ulcer. Thus demonstrating communication from the skin to underlying bones, joints, tendons, and other structures is key. Careful examination of the soft tissues at MR imaging allows the radiologist to determine the extent of soft tissue infection, the presence of abscesses and septic tenosynovitis, as well as the presence of necrotic tissue. Pitfalls include fracture, neuropathic osteoarthropathy, neoplasia, and noninfectious inflammatory conditions such as gout.

Distal clavicular osteolysis in adults: association with bench pressing intensity.

OBJECTIVES: To investigate the association between distal clavicular osteolysis (DCO) and bench pressing intensity. METHODS: From a retrospective review of MRI shoulder reports of individuals between 20 and 40 years of age, 262 male patients with DCO and 227 age-matched male patients without DCO were selected. All patients had completed a bench pressing questionnaire. The patients' bench pressing frequency (times per week), duration (years of bench pressing), bench pressing weight (maximum bench pressing weight with one repetition = 1RM) and the ratio of bench pressing weight to body weight were compared between both groups using Chi-square and Mann-Whitney tests. RESULTS: The results showed that 56 % (146/262) of patients with DCO were high-intensity bench pressers (1RM more than 1.5 times the body weight) compared to 6 % (14/227) in patients without DCO. High-intensity bench pressing was a risk factor for DCO (OR = 19; 95 %CI = 11-35; p < 0.001). Low-intensity bench pressing (1RM less than 1.5 times the body weight) was not a risk factor for DCO (OR = 0.6; 95 % CI = 0.4-0.8). High frequency (>1×/week) and duration (>5 years) of bench pressing were risk factors. In bench pressers who suffered from DCO, the mean 1RM was 283 lbs (±SD 57) compared to 209 lbs (±SD 60) in bench pressers not affected by DCO (p < 0.001, Mann-Whitney). CONCLUSIONS: High-intensity, but not low-intensity bench pressing is a risk factor for DCO.