Faculty Bibliography

MR imaging is the standard diagnostic modality that provides a comprehensive and accurate assessment for both osseous and soft-tissue pathologic conditions of the shoulder. This article discusses standard MR imaging and arthrography protocols used routinely in clinical practice, as well as more innovative sequences and reconstruction techniques, facilitated by the increasing availability of high-field-strength magnets and multichannel phased array surface coils and incorporation of artificial intelligence. These exciting innovations allow for a more detailed and diagnostic imaging assessment, improvements in image quality, and more rapid image acquisition.

The focus of this article is to illustrate various pathologic entities and variants, heralding disease about the ankle, based on scrutiny of AP radiographs of the ankle, with correlative findings on cross-sectional imaging. Many of these entities can only be detected on the AP ankle radiograph and, if not recognized, may lead to delayed diagnosis and persistent morbidity to the patient. However, a vigilant radiologist, equipped with the knowledge of the characteristic appearance and typical locations of the imaging findings, should be able to make the crucial initial diagnosis and surmise additional findings to be confirmed on cross-sectional imaging.

Background/Purpose : Prevalence of sacroiliitis (SI) in Crohn's disease (CD) varies widely (range 4% -39%), depending on criteria utilized to define the disease (e.g. inflammatory back pain, plain radiographs or MRI). Sacroiliitis may remain underdiagnosed in CD patients given lack of association with clinical symptoms of back pain and CD activity. However, patients with CD often undergo magnetic resonance enterography (MRE) to assess extent, severity of small bowel CD and radiographic healing, affording clinicians the opportunity to evaluate for the presence of active and/or chronic SI. We sought to identify the prevalence of sacroiliitis in CD patients utilizing MRE and determine its relationship with CD activity, especially with concurrent biologic therapy. Methods : All CD subjects undergoing MRE between years 2014-2018 at a large IBD referral center were identified. A musculoskeletal radiologist, blinded to clinical data, reviewed all MRE exams for the presence of acute bone marrow edema (BME) lesions and chronic lesions suggestive of acute and chronic SI, respectively. A second radiologist, also blinded, assessed MRE for mucosal CD activity using validated measures. Charts were reviewed for demographics, IBD characteristics, presence of back pain, clinical and endoscopic activity of CD, and Crohn's therapies within 3 months of MRE. Comparisons were made between CD subjects with and without SI using chi-square test. Univariate and multivariate logistic regression were used to determine risk factors of SI. Results : 258 subjects with CD underwent MRE during the study period with a mean age of 35 years old, 53% (n=138) were male, and mean duration of CD at the time of MRE was 9 years. Few reported back pain (8%) and 14% had previously seen a rheumatologist. Overall, 17% (n=45) of patients had MR evidence of sacroiliitis (Table 1). Female gender, presence of back pain, and later age of CD diagnosis were associated with signs of sacroiliitis (p=0.05, p< 0.001, p=0.04 respectively; Table 2). Stricturing phenotype was associated with a lower rate of SI (7% vs. 24%; p=0.018), but inflammatory or penetrating phenotypes were not. CD location, activity as noted by clinical scores, endoscopic disease activity, or radiographic disease activity on MRE, were not associated with sacroiliitis (Table 2). On multivariable analysis, back pain was associated with the presence of sacroiliitis on MRE (OR 3.0, 95% CI 1.1-5.6; p=0.04). Concurrent CD therapy with biologics did not lower the risk of sacroiliitis. Conclusion : Although often underdiagnosed, SI is a common comorbid condition in CD. While recent history of back pain was associated with the presence of sacroiliitis visualized on MRE, no correlations were found with other clinical and endoscopic markers of CD activity. Moreover, concurrent CD therapy, especially biologics, was not associated with a lower risk of sacroiliitis on MRE. With limited clinical clues and CD characteristics to suggest sacroiliitis, gastroenterologists can utilize MRE as a screening tool to detect SI and refer CD patients to rheumatologists. Presence of SI on MRE in CD patients with back pain may help identify a subset of individuals likely to benefit from switching to therapies with proven efficacy in axial SpA

OBJECTIVE. The purpose of this article is to describe Stener-like lesions of the superficial medial collateral ligament (sMCL) of the knee, which, to our knowledge, have not yet been reported in the radiologic literature. This lesion, defined as a distal tear with interposition of osseous or soft-tissue structures between the ligament and its tibial attachment, often requires surgical intervention. MATERIALS AND METHODS. Knee MRI examinations of grade 3 sMCL tears were identified via a search of department imaging and orthopedic case files of medial collateral ligament (MCL) tears for the period of January 2010-April 2017 using the keywords "complete MCL tear" or "near complete MCL tear." Two musculoskeletal radiologists reviewed the MRI examinations. The location of the sMCL tear, presence of a Stener-like lesion, associated ligamentous injuries, and surgical findings were recorded. RESULTS. Review of 65 knee MRI examinations identified 20 cases of distal tibial grade 3 sMCL tear. Of the distal tears, 12 (60%) were Stener-like lesions and six (30%) were borderline lesions. Of these 18 cases, 14 (78%) were associated with multiligament knee injury and nine (50%) underwent MCL repair or reconstruction. Ten of the 12 (83%) Stener-like lesions were displaced superficial to the pes anserinus and two (17%) were entrapped, one in a reverse Segond fracture and one in the femorotibial compartment. CONCLUSION. Stener-like lesions represent a high percentage of tibia-sided sMCL avulsions, are found most often with pes anserinus interposition, and are frequently associated with multiligamentous injury, suggesting high-energy trauma. MRI diagnosis is important because interposition preventing anatomic healing and potential secondary valgus instability often prompt surgical intervention.

Purpose: Soft tissue reconstruction of the coracoclavicular ligament is an increasingly common treatment approach for significant acromioclavicular joint separation injury. We have anecdotally noted loss of acromioclavicular joint reduction, coracoclavicular interval widening, distal clavicular osteolysis, and widening of osseous tunnels on follow-up radiographic exams. Our purpose is to report radiographic features and complications following coracoclavicular soft tissue reconstruction.
Material(s) and Method(s): Retrospective query of our imaging database identified 55 cases of coracoclavicular ligament reconstruction. Cases with at least one month of follow-up and available operative report were reviewed with attention to : 1. alignment of the acromioclavicualar joint, 2. coracoclavicular interval widening, 3. radiographic features of distal clavicular osteolysis, and 4. widening of the reconstruction tunnel.
Result(s): 32 patients with post-operative imaging following coracoclavicular ligament reconstruction (23 male, 9 females; average age 43, age range 24-64, imaged 1 to 34 months following surgery, average 9.5 months) were included. Loss of acromioclavicular joint reduction was the most common imaging finding at follow-up (n = 25, 78%), with 88% of cases seen within 6 months of surgery. 19 (76%) patients with loss of acromioclavicular reduction progressed to coracoclavicular interval widening. Distal clavicular osteolysis was seen in 21 patients (66%), with 90% of cases seen within 6 months of surgery. Reconstruction tunnels widened on average 2 mm (range 0 - 4 mm). Revision surgery was required in 5 patients (16%), with 80% of revisions occurring more than a year following surgery.
Conclusion(s): Loss of acromioclavicular joint reduction, distal clavicular osteolysis, and tunnel widening are frequently demonstrated after coracoclavicular ligament reconstruction. Radiologists should be aware of the frequently observed imaging findings following coracoclavicular reconstruction. Attention to early loss of reduction or distal clavicular may guide treatment approach and impact patient outcomes

The midtarsal (Chopart) joint complex consists of the talonavicular and calcaneocuboid joints and their stabilizing ligaments. Detailed assessment of this complex at MRI can be challenging owing to frequent anatomic variation and the small size of the structures involved. Nevertheless, a wide spectrum of pathologic conditions affect the joint complex, and its imaging evaluation deserves more thorough consideration. This review focuses on MRI evaluation of normal ligamentous anatomy and common variations about the Chopart joint, presenting practical imaging tips and potential diagnostic pitfalls. Imaging findings across a spectrum of traumatic Chopart joint injuries are also reviewed, from midtarsal sprains to Chopart fracture-dislocations. Midtarsal sprains-commonly associated with ankle inversion injuries-are emphasized, along with their often predictable radiographic and MRI injury patterns. Online DICOM image stacks are available for this article. ^©RSNA, 2018.

OBJECTIVE:The purpose of this study is to familiarize the radiologist with knee arthroscopy, including the setup, equipment, and standard procedure used. This is followed by a discussion of the strengths and weaknesses of knee MRI and arthroscopy and presentation of images showing normal knee anatomy and pathologic findings. CONCLUSION/CONCLUSIONS:By having an understanding of basic arthroscopic principles as well as the strengths and limitations of MRI and arthroscopy in the diagnosis of knee abnormalities, radiologists will improve image interpretation and add value to interactions with the consulting orthopedic surgeon.

PURPOSE: The purpose of the current study was to evaluate the short-term results of meniscal root repair surgery, assessing clinical and radiographic outcomes, utilizing MRI to assess root healing and extent of post-operative extrusion. METHODS: This was a single-center, retrospective study evaluating patients who had undergone a medial meniscus posterior root repair using a transtibial pullout technique with two locking cinch sutures. Demographic data were collected from patient charts. Clinical outcomes were assessed with pre- and post-operative IKDC and Lysholm scores. Pre-op scores were taken at the patients' initial clinical visit, mean 1.55 months prior to surgery (+/- 1.8 months, min 0.3, max 7.3). Radiographic outcomes were assessed with MRI evaluation of root healing, meniscal extrusion, and cartilage degeneration using ICRS criteria. Tunnel placement was evaluated and compared to the anatomic footprint. RESULTS: Eighteen patients (47.2 years +/- 11.9) were evaluated at mean follow-up of 24.9 months (+/- 7.2, min 18.4, max 35.6). The IKDC score significantly increased from 45.9 (+/- 12.6) pre-operatively to 76.8 (+/- 14.7) post-operatively (p < 0.001). Lysholm scores also increased from 50.9 (+/- 7.11) to 87.1 (+/- 9.8) (p < 0.001). Mean tunnel placement was 5.3 mm (+/- 3.5, range 0-11.8) away from the anatomic footprint. Mean extrusion increased from 4.74 mm (+/- 1.7) pre-operatively to 5.98 (+/- 2.8) post-operatively (p < 0.02). No patients with > 3 mm of extrusion on pre-operative MRI had < 3 mm of extrusion on post-operative MRI. Both medial femoral condyle and medial tibial plateau ICRS grades worsened significantly (p < 0.02 and p < 0.01, respectively). On MRI, one root appeared completely healed, 16 partially healed, and one not healed. CONCLUSION: Patients treated with the transtibial suture pull-out technique with two locking cinch sutures had improved clinical outcomes, but only partial healing in the majority of cases, increased extrusion, and progression of medial compartment cartilage defect grade on follow-up MRI. Patients should be counseled that although clinical outcomes in the short term may be optimistic, long-term outcomes regarding progression to degenerative arthritis may not be as predictable. CLINICAL LEVEL OF EVIDENCE: III.