Faculty Bibliography

MRI is central to evaluation of the post-operative knee, providing a comprehensive assessment of reconstructions, repairs, and cartilage restoration procedures. Accurate interpretation requires familiarity with operative techniques, graft biology, and the expected temporal evolution of post-operative imaging findings. This review presents a practical, imaging-based approach to contemporary knee surgery. Emphasis is placed on anterior cruciate ligament reconstruction, the renewed interest in primary repair, and common mechanisms of failure. Meniscal surgery, including repair, root repair, centralization, and transplantation, is discussed with attention to expected post-operative MRI appearances and findings suggestive of recurrent or failed repair. Finally, cartilage resurfacing and restoration techniques are reviewed using a systematic framework to assess graft infill, integration, surface congruity, and subchondral bone response. By integrating surgical context with time-dependent MRI findings, this review aims to provide radiologists with a practical framework to distinguish expected post-operative changes from complications, improving diagnostic confidence and clinical relevance of post-operative knee MRI interpretation.

Thirty-three panelists from 23 institutions participated in a three-round Delphi consensus process to establish interdisciplinary guidelines for reporting knee MRI findings on 11 meniscus topics: MRI criteria for tears, possible tears, tear patterns, tear descriptors, intrameniscal descriptors, meniscal roots, posteromedial meniscocapsular junction, meniscus extrusion, assessment of the postoperative meniscus, retear descriptors, and ancillary findings. All panelists completed all Delphi rounds. In round 1, 350 free-text entries (mean, 31.8 entries per topic ± 2.2 [SD]) were submitted. In round 2, 32 statements (mean, 2.9 entries per topic ± 1.6) were collected from 11 teams (one orthopedic surgeon and two musculoskeletal radiologists per team), with 75% (24 of 32 panelists) achieving consensus using a 9-point Likert scale. Consensus was defined as a score of at least 7 (≥80% of panelists) and a median score of at least 7 (IQR ≤3). In round 3, all statements achieved consensus. Between rounds 2 and 3, agreement significantly increased (P < .05) among all panelists on the topics of possible tears (to express uncertainty) and tear descriptors (for treatment planning), among orthopedic surgeons on MRI criteria for tear and the assessment of the postoperative meniscus (specifically on reporting equivocal findings and the use of MR arthrography), and among radiologists on tear patterns, intrameniscal descriptors, meniscal roots, and retear descriptors.

The extensor mechanism of the knee is essential for maintaining normal daily function and for activities such as walking and athletic performance. It comprises the quadriceps muscles and tendon, patella and peripatellar fat pads, patellofemoral joint and retinacula, patellar tendon, and tibial tuberosity. Disruption of any component can result in pain, instability, or loss of active extension. Owing to its superficial location and continuous biomechanical loading, it is particularly vulnerable to acute trauma, repetitive microtrauma, chronic degeneration, and traction apophysitis in the pediatric population. Imaging is essential for accurately differentiating between diagnoses and guiding management. Radiographs remain indispensable for assessing patellar height, fracture morphology, and skeletal variants, while computed tomography (CT) is a reliable preoperative tool for defining fracture configuration, comminution, and articular involvement. Ultrasound (US) offers dynamic, high-resolution evaluation of tendons and retinacula, facilitating differentiation of partial from complete tears and assessment of postoperative integrity. Magnetic resonance imaging (MRI) provides comprehensive characterization of soft tissues, bone marrow, cartilage, and associated intra-articular pathology, and is central to preoperative planning in complex injuries and patellofemoral instability. In addition to diagnosis, imaging findings directly influence treatment decisions, including fracture fixation strategies, tendon repair or augmentation, and treatment selection. Postoperative imaging plays a vital role in monitoring healing, detecting complications such as construct elongation, re-tear, hardware irritation, and recurrent instability, and guiding rehabilitation. This review highlights the radiological anatomy and injury patterns of the knee extensor mechanism, emphasizing that integrated use of radiographs, ultrasound, and MRI enables accurate, clinically relevant assessment.

OBJECTIVE:To determine inter-reader reliability and diagnostic accuracy of MSKI-RADS among early-career radiologists with different experience levels. MATERIALS AND METHODS/METHODS:This is a retrospective multicenter study of MRIs of proven musculoskeletal (MSK) infections. MSKI-RADS categories included: 0-incomplete imaging, I-negative for infection, II-superficial soft tissue infection, III-deeper soft tissue infection, IV-possible osteomyelitis (OM), V-highly suggestive of OM, VI-known OM, and NOS-nonspecific bony lesions unrelated to infection. There were 22 readers from 9 institutions with 1-8 years of radiology experience, including radiology residents, MSK radiology clinical fellows, and junior MSK attendings. After initial training with expert readers, a dataset of 210 cases across a spectrum of extremity infections from a single institution was evaluated. The readers recorded the following for each case: MSKI-RADS score, final qualitative diagnosis, and confidence levels for both. Inter-reader agreements (ICC) and accuracy were obtained. RESULTS:Among 210 cases, there were 17 negative, 32 superficial soft tissue infections, 39 deeper soft tissue infections, 24 possible OM, 41 highly suggestive of OM, 18 known OM, and 39 NOS cases. A moderate inter-reader agreement was seen for 22 readers (ICC: 0.57 (CI = 0.52, 0.67)). The average true positive rates for non-infectious cases (I and NOS), soft tissue infection (II and III), and bony infection (IV and V) were 70% (95% CI: 67-73%), 66% (95% CI: 63-68%), and 82% (95% CI: 80-84%), respectively. Average true positive rates for classes V and VI were 80% (95% CI: 77-82%) and 86% (95% CI: 82-89%), respectively. Overall, MSKI-RADS reader accuracy was 66 ± 10%, higher than the qualitative diagnosis accuracy of 59 ± 11% (p < 0.05). Average confidence levels for MSKI-RADS score and final qualitative diagnosis were 3.56 ± 0.91 and 3.52 ± 0.92, respectively (p > 0.05). CONCLUSION/CONCLUSIONS:MSKI-RADS is an accurate and reliable MRI-based classification system for the diagnosis of a spectrum of musculoskeletal infections among early-career radiologists, like expert readers. KEY POINTS/CONCLUSIONS:Question What is the inter-reader reliability and diagnostic accuracy of the musculoskeletal infection reporting and data system (MSKI-RADS) among early-career radiologists with different experience levels? Findings Overall reader accuracy using MSKI-RADS was significantly higher than the accuracy for final qualitative diagnoses, like the results of the initial validation study with expert readers. Clinical relevance MSKI-RADS is valid and reliable for diagnosis and grading of a spectrum of extremity musculoskeletal infections for early career radiologists of different experience levels, like expert readers.

A standardized guideline and scoring system are recommended for the imaging evaluation of musculoskeletal infections on MR imaging. The Musculoskeletal Infection Reporting and Data System (MSKI-RADS) is a recently developed and validated classification system using MR imaging that can be used to classify the severity and extent of musculoskeletal infections, improve radiology-pathology concordance, and outline the corresponding management recommendations. This review article explains MSKI-RADS and discusses the different elements of this system in detail with a review of pertinent literature so that the readers can apply it in their practices. The work outlines the technical considerations for optimal MR imaging for evaluating various musculoskeletal infectious lesions, details the severity scales with examples of various conditions that fall under each class, and outlines related patient management recommendations. The readers can learn about the MSKI-RADS classification system and apply the gained information from this article to improve MRI interpretations in their practice and increase the effectiveness of their multidisciplinary communications. This standardized system will also allow longitudinal data collection and tracking for future research purposes. CRITICAL RELEVANCE STATEMENT: MSKI-RADS is a recently developed and validated MRI-based guideline for musculoskeletal infections in extremities. A comprehensive understanding of these classifications can facilitate improved standardized diagnostic reporting of musculoskeletal infections on MRI and better patient outcomes. KEY POINTS: Current terminology for describing musculoskeletal infections on MRI is nonspecific, resulting in confusing diagnostic reports. A standardized guideline and scoring system are critical for improving diagnostic reporting of musculoskeletal infections on MRI. MSKI-RADS is a recently developed and validated MRI-based guideline that can be used to characterize musculoskeletal infections in extremities. MSKI-RADS is a meaningful tool that facilitates improvements in standardized reporting and treatment protocols, multidisciplinary communications, and longitudinal data collection.

BACKGROUND:The objective of this study was to survey a cross-section of US female orthopaedic surgeons evaluating their education and attitudes on radiation safety and adherence to safety recommendations. METHODS:An online survey was distributed to female orthopaedic surgery faculty through the Forum, a society for women in orthopaedic surgery, and through internal institutional education networks (residency and fellowship programs). The first component of the survey gathered demographic information including practice setting, US state, and years in practice. The second component was a 10-question knowledge assessment. The third component captured personal experiences among respondents including satisfaction with radiation safety training, radiation safety practices, and level of concern regarding exposure risk. Responses from 66 participants from differing geographic locations were collected using Research Electronic Data Capture. RESULTS:Sixty-six female orthopaedic surgeons from 21 states completed the survey. Regular dosimeter usage was reported by 24.2% of respondents, and 36.4% of respondents reported always having well-fitted radiation protective equipment provided. The majority (56.1%) stated that they worry about the risks of radiation to their health. Regarding their radiation safety training, 60.6% of respondents rated their training as unsatisfactory or extremely unsatisfactory, and 90.9% of respondents stated that they think training efforts for radiation safety can improve. CONCLUSIONS:Female orthopaedic surgeons demonstrated an inadequate knowledge of adherence to radiation safety protocols and the majority expressed concern with long-term radiation exposure, particularly regarding health and pregnancy risk. To enhance radiation safety awareness and adherence among female orthopaedic surgeons, strategies should be tailored to this demographic, fostering confidence in their knowledge of radiation exposure and bolstering safety measures.

PURPOSE/OBJECTIVE:To evaluate the safety and efficacy of genicular artery embolization and its longitudinal effects on biomarkers implicated in knee osteoarthritis (KOA) pathogenesis.. MATERIALS AND METHODS/METHODS:This is a prospective, single-arm clinical trial of patients with symptomatic KOA resistant to conservative therapy for greater than 3 months. Twenty-five patients who underwent GAE using 250-μm microspheres were included. Patient reported outcome measures were evaluated at baseline and 1-, 3-, and 12-months following GAE. Blood samples were collected for biomarker analysis. Magnetic resonance imaging was obtained at baseline and 3 months post GAE. The primary endpoint was the clinical success rate at 12 months. Baseline and follow-up outcomes were analyzed using the Wilcoxon matched-pairs signed-rank test. RESULTS:The technical success was 100%, with no significant adverse events. The clinical success rate was 62%. The mean VAS pain score for the target knee decreased by 48.5% at 1 month, 50.8% at 3 months, and 55.4% at 12 months (p < .001). WOMAC pain scores improved by 39.6% at 1 month, 50.1% at 3 months, and 43.7% at 12 months (p < .001). There was a statistically significant decrease in the serum levels of vascular endothelial growth factor (VEGF) and Interleukin-1 receptor antagonist (IL-1Ra) at 12 months. The remaining biomarkers showed no significant change. CONCLUSIONS:GAE is a safe treatment for symptomatic KOA, providing clinically significant pain relief for a subset of patients. The observed reductions in serum VEGF and IL-1Ra levels following GAE may contribute to local pain relief and decreased inflammation in the knee joints.

BACKGROUND:The goal of this study was to utilize preoperative computed-tomography(CT) scans to identify differences in the Hounsfield units(HU) of the acromion in patients who did and did not develop a postoperative acromial and scapular-spine fracture(ASF) after primary reverse total shoulder arthroplasty (rTSA). METHODS:A retrospective analysis was performed at a single institution. All patients undergoing a rTSA with either a 135° neck/shaft angle(NSA) humeral inlay design combined with a lateralized center-of-rotation(COR) glenosphere or a 145° NSA onlay combined with a medialized COR glenosphere design between 2011-2021 with a minimum follow-up of 24-months were included. Demographic characteristics and clinical outcome metric scores were recorded. Preoperative CT scans were analyzed to obtain acromion trabecular bone density measurements in HU in each zone of the scapula based on the Levy classification. Radiographic parameters were evaluated to determine their association with ASF. RESULTS:In total 263-patients were included, 140-patients with a 135° NSA humeral-inlay design;123-patients with a 145° NSA humeral-onlay design. There were no significant differences in baseline demographics between cohorts. The rate of ASF was 6.4%(9/140) for the 135° NSA-inlay-design versus 2.4%(3/123) in the 145° NSA-onlay design. In the non-fracture cohort there was a linear increase in bone density from zone-1(173.9HU)→zone-3(396.5HU)(lateral→medial). In the fracture cohort there was a decrease in bone density from zone-1(282.6HU)→zone-3(154.5HU). Measuring preoperative bone density in all Levy specific fracture-zones resulted in an AUC of 0.96 correlating to excellent predictive value. A threshold cutoff of 99.9 resulted in a sensitivity of 91.6% and specificity of 75.3%. A HU of 99.9 in any of the three-zones resulted in OR 5.1(p<0.0001) for sustaining an ASF postoperatively. A threshold of<50HU was associated with an 8-times higher-likelihood of developing a fracture in that specific zone. Greater than 5° of superior tilt in combination with ≥24mm of distalization was associated with an OR 6.4(p=0.0004) of sustaining an ASF. CONCLUSION/CONCLUSIONS:The current study demonstrates an accurate method of measuring HU at each of the described Levy fracture zones with excellent predictability of patients who are at risk of an ASF following rTSA. Additionally, we found that a HU threshold of <50 HU at any of the three Levy zones was associated with a nearly 8 times higher likelihood of developing a fracture in that specific zone. Lastly, we found that >5° of superior tilt in combination with ≥24mm of distalization was associated with 6.4 times higher likelihood of sustaining an ASF agnostic to prosthesis design.