Faculty Bibliography

OBJECTIVE:The purpose of this study was to describe clinical experience with ultrasound-guided therapeutic procedures and associated pathologic conditions involving the peripheral nerves of the upper extremity over 5 years at a large academic institution. MATERIALS AND METHODS/METHODS:A retrospective database search of procedure codes was performed for all ultrasound-guided upper extremity peripheral nerve procedures between 2012 and 2017. Retrospective review of the electronic medical record for patient demographics, indications, interval follow-up pain relief, and complications was undertaken. Retrospective review of ultrasound and other correlative imaging findings was performed to assess for neural and perineural abnormalities. RESULTS:In total, 242 procedures performed on a cohort of 183 patients (53% women, 47% men; mean age, 53 years; range, 15-97 years) were reviewed. Nine patients underwent multifocal injections in a single encounter, and 39 underwent repeat injections of previously documented symptom generators. Perineural injections included ulnar (n = 109), median (n = 81), posterior interosseous-deep radial (n = 39), sensory branch of the radial (n = 7), anterior interosseous (n = 2), axillary (n = 2), suprascapular (n = 1), and digital (n = 1) nerves. Structural or dynamic abnormality seen either during the procedure or at preprocedural imaging included loss of normal morphologic features (n = 148), nerve subluxation (n = 8), ganglion cyst (n = 4), and neuroma (n = 7). Forty-four patients reported immediate pain relief after the procedure. Of the 89 patients with documented clinical follow-up, 52 reported a period of symptom relief (mean, 125 days), and six reported complete resolution of symptoms. Subsequent surgical procedures were performed on 32 patients, a combination of those who did (n = 12) and did not (n = 20) experience a period of symptom relief from the perineural injection. There were no complications with regard to the site or distribution of perineural injections. Three episodes of vasovagal reaction were reported. CONCLUSION/CONCLUSIONS:Ultrasound-guided percutaneous interventions for upper extremity neural abnormalities can be safely performed for a variety of indications. Real-time ultra-sound evaluation during the procedure allows assessment for neural and perineural abnormalities and tailoring of the procedure to potentially symptomatic structural abnormalities.

PURPOSE/OBJECTIVE:To correlate the histopathologic appearances of resected long head of the biceps tendon (LHBT) specimens following biceps tenodesis, with pre-operative MRI and arthroscopic findings, with attention to the radiologically normal biceps. MATERIAL AND METHODS/METHODS:Retrospective analysis of patients who had undergone preoperative MRI, subsequent arthroscopic subpectoral tenodesis for SLAP tears and histopathologic inspection of the excised sample between 2013 and 16. Those with a normal MRI appearance or mildly increased intrasubstance signal were independently analyzed by 2 blinded radiologists. A blinded orthopedic surgeon and pathologist reviewed all operative imaging and pathologic slides, respectively. RESULTS:Twenty-three LHBT resected samples were identified on MRI as either normal (Reader 1 n = 15; Reader 2 n = 14) or demonstrating low-grade increased signal (Reader 1 n = 8; Reader 2 n = 9). Of these, 86.9% demonstrated a histopathological abnormality. 50% of samples with histopathological abnormality demonstrated normal appearance on MRI. The most common reported histopathology finding was myxoid degeneration (73.9%) and fibrosis (52.2%). The most common arthroscopic abnormality was fraying (18.2%) and erythema (13.6%). Utilizing histopathology as the gold standard, the two radiologists demonstrated a sensitivity of 35.0% v 42.9%, specificity of 66.7% v 100%, PPV of 87.5% v 100%, and NPV of 13.3% v 14.3%. Corresponding arthroscopic inspection demonstrated a sensitivity of 31.6%, specificity of 66.6%, PPV 85.7% and NPV of 13.3%. There was moderate agreement between the two radiologists, κ = 0.534 (95% CI, 0.177 to 0.891), p = 0.01. CONCLUSION/CONCLUSIONS:Histopathological features of low grade tendinosis including mainly myxoid degeneration and fibrosis are frequently occult on MR imaging.

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 correlate quantitative shear wave velocities (SWV) in the supraspinatus muscle (SSM) with that of the tendon (SST), and to evaluate whether SSM SWV changes precede morphologic fatty atrophy. Materials and Methods: An IRB-approved, HIPAA-compliant study of 45 patients (22 men, 23 women) with mean age of 59 (range 39-84) was conducted. Grayscale ultrasound and shear wave elastography images of the SST and SSM were performed with a 9MHz linear transducer on a Siemens S3000 scanner with VTIQ software (Siemens). Sample volume SWV values were obtained of the proximal (PSST) and distal tendon (DSST). Mean SSM SWV was reported from the software region of interest or calculated from sample volumes. Exclusion criteria included history of rotator cuff repair and non-target measurements on bone or peribursal fat. Qualitative tendon pathology grading was as follows: 1=normal or mild tendinosis without tear, 2=moderate or severe tendinosis without tear or mild tendinosis with low-grade partial tear, 3=partial tear with at least moderate tendinosis, and 4=full-thickness tear. All patients demonstrated normal grayscale appearance of the SSM, without evidence of fatty atrophy. Pearson and Spearman rank correlations were used for statistical analysis. Results: No statistically significant correlation was found between mean SSM SWV and mean PSST, DSST, or overall tendon SWV (R=0.14, p=0.396; R=0.04, p=0.832; R=0.06, p=0.731, respectively). There was no statistically significant correlation between SSM SWV and tendon grade (R=0.13, p=0.435). Mean PSST, DSST, and overall tendon SWV demonstrated weak negative correlation with qualitative tendon grade (R=-0.22, p=0.183; R=-0.32, p=0.054; R=-0.30, p=0.045, respectively). Conclusion: Supraspinatus muscle SWV does not appear to vary with quantitative tendon SWVor qualitative tendon grading. Aweak negative correlation between supraspinatus tendon SWV and qualitative tendon grade is compatible with tendon softening with progressive tendinopathy

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