Faculty Bibliography

Emerging musculoskeletal applications for local administration of autologous bone marrow aspirate concentrate (BMAC) include treatment of fractures, osteonecrosis, osteochondral injuries, osteoarthritis, ligament injury, tendon injury, and tendonopathies. Ultrasound-guided technique for various BMAC injection sites is detailed in this technical report and our preliminary clinical experience outlined.Five patients, 1 woman and 4 men, were treated with 6 peri/intratendinous (n = 4) or intraarticular (n = 2) BMAC injections between July 5, 2015 and December 31, 2016 for the clinical indications of common hamstrings origin tendinosis (n = 4), hip labral tear (n = 1), and osteochondral lesion of the talus (n = 1).All procedures were technically successful, with BMAC locally administered to the therapeutic target and no procedural complications observed. Clinical follow-up was available for 5 of 6 procedures. Four of 5 injections resulted in self-reported symptomatic improvement (clinical follow-up range, 2-12 months). One 72-year-old man with right common hamstrings origin tendinosis reported no improvement after BMAC injection.The technology is now available to support ultrasound-guided, autologous BMAC administration by the musculoskeletal interventionalist for common indications. Our initial clinical experience is consistent with early reports in the literature. This technique is well tolerated by symptomatic patients on an outpatient basis, and rates of self-reported symptomatic relief are high. Mechanism of action, long-term safety, and long-term clinical efficacy remain largely undefined.

OBJECTIVES/OBJECTIVE:F-FDG uptake on whole-body PET-CT with MR findings and compare the degree of FDG activity between symptomatic and asymptomatic knees. MATERIALS AND METHODS/METHODS:Retrospective database query was performed using codes for knee MRI as well as whole-body PET-CT. Patients with malignant disease involving the knee or hardware were excluded. Patients who had both studies performed within 1 year between 2012 and 2017 were included for analysis. Knee joint osteoarthrosis, meniscal and ligamentous integrity, presence of joint effusion, and synovitis were assessed and recorded. Bone marrow edema lesions (BMELs) were identified, segmented, and analyzed using volumetric analysis. SUVmax was assessed over the suprapatellar joint space, intercondylar notch and Hoffa's fat pad. Symptomatic and asymptomatic knees were compared in patients with unilateral symptoms. RESULTS:Twenty-two cases (20 patients) with mean age 63.3 years (range, 36-91 years) were included. Two patients had bilateral pain. The most FDG avid regions in both symptomatic and asymptomatic knees were the intercondylar notch (SUVmax = 1.84 vs. 1.51), followed by suprapatellar pouch (SUVmax = 1.74 vs. 1.29) and Hoffa's fat pad (SUVmax = 1.01 vs. 0.87). SUVmax was significantly associated with cartilage loss (mean modified Outerbridge score) (r = 0.60, p = 0.003) and degree of synovitis (r = 0.48, p = 0023). Overall, mean SUVmax was significantly higher in the presence of a meniscal tear (1.83 ± 0.67 vs. 1.22 ± 0.40, p = 0.030). Nine patients had BMELs (volume: range = 0.6-27.8, mean = 7.79) however there was no significant association between BMEL volume and SUVmax. CONCLUSIONS:Higher FDG activity correlates with intra-articular derangement and the intercondylar notch represents the most metabolically active region of the knee.

Hip MRI and arthroscopy have important roles for the evaluation of the patient with hip pain. An understanding of what orthopedic surgeons want to know before and after hip arthroscopy as well as the limitations of arthroscopy would enable radiologists to improve their imaging interpretations and produce more clinically relevant, management guiding reports. The goal of this article is to review the basic principles of hip arthroscopy and MRI and compare their strengths and weaknesses. Normal clinically relevant hip anatomy, important pathologic conditions such as labral tears and cartilage injuries, femoroacetabular impingement specific findings like cam and pincer morphology, extra-articular conditions such as abductor and iliopsoas tendons pathology and common post-operative appearances are reviewed on MRI and arthroscopy.

OBJECTIVE:To review the MRI appearance of medial patellofemoral capsuloligamentous plication (also known as reefing or imbrication) for proximal patellar realignment in patients with patellofemoral instability. MATERIALS AND METHODS/METHODS:Retrospective analysis of our surgical and PACS databases identified cases of medial plication performed between June 2011 and July 2016. Pre- and postoperative MRI characteristics were reviewed. Correlation was made with operative reports and clinical records to define postoperative appearances on MRI. RESULTS:Forty-one patients underwent medial plication during the study period; 29 were excluded owing to a lack of postoperative imaging. Ultimately, 12 knees were included in 11 patients who had postoperative MRI studies available (8 women and 3 men, mean age 27.3 ± 10.2 years). Ten (83%) of the surgeries were performed open and 2 (17%) arthroscopically. There were differences in the post-surgical MRI appearance of medial plications carried out after surgery using the open and arthroscopic techniques. The open technique produces a "heaped up" distal vastus medialis obliquus (VMO) with centralized patellar insertion (100%), which was absent in the case of arthroscopic plication, where subtle medial retinaculum thickening was demonstrated without alteration of its patellar insertion. The mean postoperative lateral patellar and patellofemoral congruence angles measured 2.5° ± 5.6° and 12.4° ± 19.9° respectively. A significant association was found regarding change in patellofemoral alignment (p = 0.018 and p = 0.004 respectively). CONCLUSION/CONCLUSIONS:The MRI appearance of medial plication is not well described in the radiology literature; radiologists should be familiar with anticipated post-plication findings to avoid potential confusion for pathology and allow more accurate interpretation of postoperative imaging findings from this common surgery.

We describe an easily constructed, customizable phantom for magnetic resonance imaging-ultrasound fusion imaging and demonstrate its role as a learning tool to initiate clinical use of this emerging modality. Magnetic resonance imaging-ultrasound fusion can prove unwieldy to integrate into routine practice. We demonstrate real-time fusion with single-sequence magnetic resonance imaging uploaded to the ultrasound console. Phantom training sessions allow radiologists and sonographers to practice fiducial marker selection and improve efficiency with the fusion hardware and software interfaces. Such a tool is useful when the modality is first introduced to a practice and in settings of sporadic use, in which intermittent training may be useful.

Objectives: Bone marrow edema lesions (BMELs) frequently occur following acute anterior cruciate ligament (ACL) rupture secondary to the pivot-shift mechanism of injury. The aim of the current study is to evaluate whether synovial fluid biomarker concentrations are associated with bone edema lesion volume as measured by magnetic resonance imaging (MRI) in patients undergoing ACL reconstruction.
Method(s): A total of 53 patients (26 females, 27 males, mean age 35.0 years [range 18-59]) undergoing ACL reconstruction with MRI knee scans available for analysis participated in the study. Synovial fluid was collected intra-operatively and analyzed for 10 biomarkers hypothesized to be involved in inflammation and post-traumatic osteoarthritis. BMELs were identified on MRI and their volumes (cm3) were quantified on two independent occasions using FireVoxel imaging software for image segmentation and region-of-interest drawing. The correlation between synovial fluid biomarker levels and BMEL volume was evaluated using Spearman's correlation coefficient. Measurement reliability was assessed using intraclass correlation coefficient (ICC) analysis. Significance was set at p<0.05.
Result(s): Mean time from initial injury to synovial fluid aspiration was 319 days (std. dev. 892; range 15-4320) and mean lesion volumes were: tibial=6.4 cm3 (range 0-38.6); femoral=5.8 cm3 (range 0-34.0); total=12.2 cm3 (range 0-50.5). Measurement reliability of BMEL volume was excellent [ICC(2,1)=0.968 (CI 0.945-0.981)]. Analysis of patients with MRI within 30 days of injury (n=35) showed increased tibial BMEL volume was significantly (p<0.05) correlated to decreased concentrations of interleukin (IL)-6 (rho=-0.481), IL-1 receptor antagonist (rho=-0.361), and vascular endothelial growth factor (VEGF) (rho=-0.397) and increased time from injury to aspiration was correlated to decreased concentration of IL-6 (rho=-0.463), monocyte chemotactic protein-1 (rho=-0.453), VEGF (rho=-0.457), IL-1Ra (rho=-0.448), and matrix metalloproteinase (MMP)-3 (rho=-0.426). However, among all patients, synovial fluid biomarker levels had no significant correlations to BMEL volume or time from injury to aspiration.
Conclusion(s): Analysis of synovial fluid at the time of ACL reconstruction demonstrated that increased volume of injury-associated BMEL on MRI performed within 30 days of initial injury was significantly correlated to decreased concentrations of pro-inflammatory and growth factor cytokines. These findings suggest that the impact of the pivot-shift mechanism of injury and presence of BMEL may have an affect the local joint microenvironment. (Table Presented)

Purpose: To present a 4 year clinical experience with ultrasound-guided therapeutic perineural injections of upper extremity peripheral nerves and evaluate utility of ultrasound guidance for diagnosis of intrinsic or perineural pathologies. Materials and Methods: A retrospective keyword PACS search was conducted for upper extremity therapeutic perineural injections (May 2012-January 2017), yielding 342 cases. 175 were excluded because no perineural injection was performed. 5 patients underwent injection of more than one nerve during one visit, yielding 174 perineural injections among 130 patients. Retrospective chart review was undertaken to determine patient demographics, clinical indications, presence of structural pathology, as well as presence of pain relief at interval clinical follow-up. Results: 174 injections among 130 patients were reviewed (mean age=57.75 years [15-97], 68 female (52%), 62 male (48%)). The most commonly injected nerves included the ulnar (n=81, 46%) and median (n=61, 35%) nerves. The least common was the suprascapular nerve (n=1, 0.6%). Ultrasound at the time of injection revealed >1 structural abnormality in 110 (63%) cases. The most common was nerve enlargement (n= 101, 92%), although a variety of structural abnormalities were detected, including prior ulnar nerve transposition (n=7, 4%), epicondylitis (n=4, 2%), thickening at the arcade of Frohse (n=3, 2%), low triceps insertion (n=2), ganglion cyst (n=1, 0.5%), anconeus epithrochlearis (n=1, 0.5%), and post-traumatic neuromas (n=1, 0.5%). Interval clinical follow-up was available for 68 patients, of which 51 (75%) reported symptomatic relief. Complications are relatively rare, occurring in only 1 (0.4%) case. Conclusion: Ultrasound-guided perineural injections about the upper extremity can be safely performed and provide lasting symptomatic relief for a variety of clinical indications. Sonographic evaluation at the time of injection allows identification of structural abnormalities that may contribute to neuropathic symptoms and allow more specific targeting, specific therapy, or surgical guidance

PURPOSE/OBJECTIVE:To compare patellar instability with magnetic resonance imaging analysis using continuous real-time radial gradient-echo (GRE) imaging in the assessment of symptomatic patients and asymptomatic subjects. METHODS:Symptomatic patients with suspected patellofemoral maltracking and asymptomatic volunteers were scanned in real time by a radial 2-dimensional GRE sequence at 3 T in axial orientation at the patella level through a range of flexion-extension. The degree of lateral maltracking, as well as the associated tibial tubercle-trochlear groove distance and trochlea depth, was measured. Patellar lateralization was categorized as normal (≤2 mm), mild (>2 to ≤5 mm), moderate (>5 to ≤10 mm), or severe (>10 mm). The patellofemoral cartilage was also assessed according to the modified Outerbridge grading system. RESULTS:The study included 20 symptomatic patients (13 women and 7 men; mean age, 36 ± 12.8 years) and 10 asymptomatic subjects (3 women and 7 men; mean age, 33.1 years). The mean time to perform the dynamic component ranged from 3 to 7 minutes. Lateralization in the symptomatic group was normal in 10 patients, mild in 1, moderate in 8, and severe in 1. There was no lateral tracking greater than 3 mm in the volunteer group. Lateral maltracking was significantly higher in symptomatic patients than in asymptomatic subjects (4.4 ± 3.7 mm vs 1.5 ± 0.71 mm, P = .007). Lateral tracking significantly correlated with tibial tubercle-trochlear groove distance (r = 0.48, P = .006). There was excellent agreement on lateral tracking between the 2 reviewers (intraclass correlation coefficient, 0.979; 95% confidence interval, 0.956-0.990). CONCLUSIONS:The inclusion of a dynamic radial 2-dimensional GRE sequence is a rapid and easily performed addition to the standard magnetic resonance imaging protocol and allows dynamic quantitative assessment of patellar instability and lateral maltracking in symptomatic patients. With a paucity of reported data using this technique confirming that these results reach clinical significance, future work is required to determine how much lateral tracking is clinically significant. LEVEL OF EVIDENCE/METHODS:Level III, case control.

Purpose: Assess the impact of MR pelvic and lumbosacral neuorgraphy on ultrasound-guided pelvic perineural injections. Materials and Methods: A retrospective review of all ultrasound-guided pelvic perineural injections with prior MR pelvic and/or lumbosacral neurographic imaging over a 5-year period was performed. Demographics, presence of structural pathology on imaging, and immediate and interval pain relief was recorded. Results: 30 total injections were performed among 20 patients accounting for multiple injections in a single visit or multiple visits [mean age at injection: 52.03 (range 23-77), female (n= 24, 80%) male (n=6; 20%)]. In 24 cases a combination of steroid and anesthetic solution was administered. In the remaining 6 cases, only anesthetic solution was administered. Most commonly, injections involved the sciatic nerve (n = 21; 70%). Other injections in our series include pudendal (n=5, 16.7%), genitofemoral (n=2; 6.7%), lateral femoral cutaneous (n=1, 3.3%) and ilioinguinal (n= 1, 3.3%) nerves. Concurrent therapeutic procedures were performed in 10 cases (33%). Pre-procedure MR imaging revealed structural abnormality of the nerve or adjacent soft tissues in 11 of 22 MRIs performed amongst the 20 patients (50%). Pre-procedure ultrasound revealed structural abnormalities associated with the nerve in 9 cases of 19 cases that had complete documentation (47%). Of 26 injections with complete documentation, immediate improvement of symptoms was reported in 22 cases (85%). The remaining 4 cases either began with no pain (n=3), or reported no change in symptoms (n=1). Variable degrees of long-term symptom relief was achieved in 4 injections out of 11 steroid injections for which follow-up was available (37%). Conclusion: Ultrasound-guided perineural injections can be performed for treatment of a variety of pelvic neuropathies. MR imaging prior to sonographic intervention demonstrated an abnormality in nearly half of cases, and is a useful tool to appropriately target perineural injections

Purpose: Image-guided joint aspiration is often requested for clinically suspected periprosthetic joint infection (PJI). For "dry taps" when no native joint fluid can be aspirated, a lavage with non-bacteriostatic saline can be performed. The purpose of this study is to determine the diagnostic utility of lavage versus native joint fluid aspiration in the setting of clinically suspected PJI. Materials and Methods: IRB approval was obtained and informed consent was waived for this retrospective study. A PACS search from 2011- 2017 for image-guided aspirations yielded 918 procedures, of which 630 were excluded for non-articular and non-arthroplasty aspirations, antibiotic cement spacers, and lack of clinical information in the electronic medical record. The study cohort included 288 procedures from 173 patients who underwent operative or non-operative management. The reference standard was the intraoperative culture for operative patients and clinical follow-up for conservatively managed patients. A Fisher exact test was used for statistical analysis. Results: The study cohort consisted of 98 females, 75 males, mean age 64 (range 34-90) with the following arthroplasty types: 176 hips, 65 knees, and 47 shoulders. Of 288 procedures, 105 were performed with lavage and 183 were native joint fluid aspirations; 112 were subsequently operatively managed. The mean follow-up for non-operative patients was 5 months (range 0-42). For native joint fluid aspiration versus lavage, accuracy was 81% vs. 73% (p=0.14), sensitivity was 58% vs. 28% (p=0.03), specificity was 88% vs. 91% (p=0.66), negative predictive value was 89% vs. 77% (p=0.02), and positive predictive value was 55% vs. 53% (p=1.00), respectively. Conclusion: Lavage is less sensitive with a lower negative predictive value for the diagnosis of PJI compared to native joint fluid aspirations, possibly due to a lower pretest probability of infection and the inherent dilutional effects of the procedure