Faculty Bibliography

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.

OBJECTIVE:Injuries at the calcaneocuboid and talonavicular joint have been described as two distinct, unrelated entities in the radiology literature. Our purpose was to assess the coexistence of these injuries using radiography and MRI and to correlate our findings with radiologic and clinical diagnoses. MATERIALS AND METHODS/METHODS:Twenty-one patients with injury at the anterior calcaneal process on radiographs or MR images were retrospectively assessed for concomitant injury at the talonavicular joint. Radiologic and clinical diagnoses and treatment were documented. McNemar and kappa statistics were calculated; p values < 0.05 were considered statistically significant. RESULTS:Radiographic and MRI rates of detection of injuries across the Chopart joint were statistically different. Calcaneocuboid avulsion fractures were evident on 48% of radiographs and 100% of MR images (p = 0.001). Talonavicular joint injuries were evident on 38% of radiographs and 76% of MR images (p = 0.008). Concomitant injury at both joints was evident on 14% of radiographs and 76% of MR images (p < 0.0001). Interrater agreement was 0.488-0.637 and 0.286-0.364 for talonavicular and 0.144-0.538 and 0.976-1 for calcaneocuboid injuries on radiography and MRI, respectively. Sixty percent of calcaneocuboid fractures were prospectively missed on radiography (none on MRI), whereas 38% and 25% of talonavicular findings were missed on radiography and MRI, respectively. Sixty percent of injuries were clinically misdiagnosed as ankle sprains. Chopart joint injury was never mentioned in prospective clinical or imaging diagnoses. CONCLUSION/CONCLUSIONS:Calcaneocuboid and talonavicular injuries commonly coexist. Radiographs underestimate severity of injury; MR images show more subtle abnormalities. Lack of mention of Chopart joint injury clinically and on imaging reports underlies the need for greater familiarity with this entity.

OBJECTIVE: This study determined the frequency and MRI appearance of osseous and ligamentous injuries in midtarsal (Chopart) sprains and their association with ankle sprains after acute ankle injuries. Prospective diagnosis of and interobserver agreement regarding midtarsal injury among musculoskeletal radiologists were also assessed. SUBJECTS AND METHODS: Two cohorts with ankle MRIs were identified via a digital PACS search: patients who had undergone MRI within 8 weeks after ankle injury and control subjects who had not sustained ankle trauma. Studies were retrospectively reviewed in consensus as well as independently, assessing ligamentous and osseous injury to the Chopart joint (calcaneocuboid and talonavicular joints) and associated lateral collateral and deltoid ligamentous injury. Interobserver agreement was calculated, and prospective radiology reports were reviewed to determine the musculoskeletal radiologist's familiarity with Chopart joint injury. RESULTS: MR images of control subjects (n = 16) and patients with ankle injury (n = 47) were reviewed. The normal dorsal calcaneocuboid and calcaneocuboid component of bifurcate ligaments were variably visualized; the remaining normal ligaments were always seen. Eleven patients (23%) had midtarsal ligamentous and osseous injury consistent with midtarsal sprain (eight acute or subacute, one probable, and two old). Six (75%) of eight acute or subacute cases had coexisting lateral collateral ligament injury. Eighty-nine percent of osseous injuries were reported prospectively, but 83% of ligamentous injuries were missed. Substantial interobserver agreement was achieved regarding diagnosis of midtarsal sprain. CONCLUSION: Midtarsal sprains are commonly associated with acute ankle injury and with ankle sprains. Presently, midtarsal sprains may be underrecognized by radiologists; thus, greater familiarity with the MRI spectrum of ligamentous and osseous injuries at the Chopart joint is important for accurate diagnosis and clinical management.

PURPOSE: To compare diagnostic performance of a 5-min knee MRI protocol to that of a standard knee MRI. MATERIALS AND METHODS: One hundred 3 T (100 patients, mean 38.8 years) and 50 1.5 T (46 patients, mean 46.4 years) MRIs, consisting of 5 fast, 2D multi-planar fast-spin-echo (FSE) sequences and five standard multiplanar FSE sequences, from two academic centers (1/2015-1/2016), were retrospectively reviewed by four musculoskeletal radiologists. Agreement between fast and standard (interprotocol agreement) and between standard (intraprotocol agreement) readings for meniscal, ligamentous, chondral, and bone pathology was compared for interchangeability. Frequency of major findings, sensitivity, and specificity was also tested for each protocol. RESULTS: Interprotocol agreement using fast MRI was similar to intraprotocol agreement with standard MRI (83.0-99.5%), with no excess disagreement (/= 0.215), except more ACL tears on fast MRI (p = 0.021) and more cartilage defects on standard MRI (p < 0.001). Sensitivities (59-100%) and specificities (73-99%) of fast and standard MRI were not significantly different for meniscal and ligament tears (95% CI for difference, -0.08-0.08). For cartilage defects, fast MRI was slightly less sensitive (95% CI for difference, -0.125 to -0.01) but slightly more specific (95% CI for difference, 0.01-0.5) than standard MRI. CONCLUSION: A fast 5-min MRI protocol is interchangeable with and has similar accuracy to a standard knee MRI for evaluating internal derangement of the knee.

OBJECTIVE: The bare spot (BaS) is a central, well-circumscribed focal defect in the glenoid articular surface, with reported adult incidence of 1-2%. We aimed to reassess MRI features of BaS in the pediatric population and determine its etiology. MATERIALS AND METHODS: A retrospective search of our database from June 2014 to October 2015 was performed for shoulder MRI in patients between 5 and 25 years and then subdivided into four groups: group 1, 5-10 years; group 2, 10-15 years; group 3, 15-18 years; group 4, 20-25 years. BaS was defined as a well-marginated, central defect of increased signal in the articular surface of the glenoid, seen on at least two planes, without evidence of underlying glenoid pathology. Presence, location and size along with clinical indications were documented. RESULTS: A final cohort of 253 patients revealed 23 BaS, 3.5% in group 1, 20% in group 2, 5% in group 3 and 4% in group 4. There was a significantly higher incidence in group 2 (p = 0.007) compared to group 3 and p = 0.002 compared to group 4. Location was mainly central. Mean size was significantly bigger in group 2 compared to group 3 and 4. Distribution showed the highest number at 14-15 years of age. Instability was higher in groups 3 and 4. CONCLUSION: Incidence of BaS in group 2 was significantly higher than in other age groups and higher than in adults. BaS was also larger compared to other populations. These findings support a developmental theory, explained by the centripetal ossification of the glenoid.