Fluoroscopy-guided injections of the upper extremity: pearls and pitfalls.

Fluoroscopy guidance is commonly utilized for injections in the upper extremity, with increased accuracy for injection placement compared to blind injection. Injection of the glenohumeral joint is the most commonly performed upper extremity procedure. However, there are a number of other sites which can be easily injected under fluoroscopy including the acromioclavicular joint, subacromial subdeltoid bursa, biceps tendon sheath, scapulothoracic bursa, elbow, wrist, first CMC joint, and pisotriquetral joint. Fluoroscopy can be used to guide injections into the glenohumeral, elbow, or wrist joints preceding MR arthrography. While there are technique similarities when injecting any of these sites, some particular approaches and pitfalls are unique to each anatomic site.

Assessing the impact of adding bupivacaine on immediate and delayed post-procedure pain scores in interlaminar epidural steroid injections.

OBJECTIVE: A local anesthetic is frequently administered as part of a lumbar epidural steroid injection (LESI); however, there is a rare potential for this to result in transient paralysis if administered incorrectly. The purpose of this retrospective study is to determine if the addition of bupivacaine significantly improves patient-reported pain scores. MATERIALS AND METHODS: This retrospective review includes patients undergoing LESI over an approximately 1 year time span. Pre-procedure, immediate post-procedure, and 1-week integer scaled pain scores were recorded. Ordinal regression was used to compare the distributions of the aggregated ordinal pain score categories between bupivacaine- and non-bupivacaine-injected patients. RESULTS: Two hundred fifty-eight patients met the inclusion criteria (126F:132 M, mean age 64.7 years) with 164 receiving bupivacaine and steroids and 94 receiving steroids alone. The relative frequency distributions for pre-injection pain did not differ between the bupivacaine patients and the non-bupivacaine patients (p = 0.114). Similarly, the relative frequency distributions for immediate and 1-week post-procedure pain did not differ between the bupivacaine patients and the non-bupivacaine patients (p = 0.293 at immediate time point and p = 0.306 at 1-week time point). Odds ratios comparing pain severity change between the bupivacaine and non-bupivacaine patients also were not significantly different at either the immediate post-procedure (p = 0.769) or 1-week (p = 0.203) time points. CONCLUSION: The lack of a significant downward shift in the bupivacaine patients' post-procedure pain scores compared to the non-bupivacaine patients' post-procedure pain scores raises doubts about bupivacaine's utility as a standard component of a lumbar epidural injection.

Ultrasound-guided percutaneous needle tenotomy using Tenex system for refractory lateral epicondylitis; short and long-term effectiveness and contributing factors.

BACKGROUND: Ultrasound-guided percutaneous needle tenotomy (USPNT) has been proposed as an alternative treatment to surgical intervention for lateral epicondylitis (LE). The Tenex system (Tenex Health Inc., Lake Forest, CA, USA) for USPNT is an ultrasonic device involving a needle which oscillates at high frequency to debride and aspirate diseased tendon under ultrasound image guidance. This investigation evaluates the efficacy of USPNT using the Tenex system for LE refractory to conservative management. We also seek to evaluate patient-specific factors which may correlate with treatment response. MATERIALS AND METHODS: PRTEE (Patient-Rated Tennis Elbow Evaluation) and DASH (Disabilities of the Arm, Shoulder, and Hand) questionnaires were completed before performing the Tenex USPNT for all consecutive patients over a course of 38 months (Feb 2015-Mar 2018). Patients were contacted for follow-up evaluations. Paired t test was used to evaluate significant changes in treatment response (p < 0.05). The univariate Tobit regression model was applied followed by multivariate Tobit model with forward selection algorithm. All models were adjusted by preoperative score and follow-up duration. RESULTS: A total of 37 patients (average age 51± 9 years, M/F:15/22) with refractory LE were included (mean follow-up, 531 days; range, 65-1148 days). Tenex USPNT significantly improved PRTEE and DASH scores (p < 0.001). In some patients, this decrease persisted for up to 3 years after intervention. A significant association between treatment response and post-procedure physical therapy (PT) was present. Post-procedure PT contributes to 60, 68, 59, and 50% of reduction in PRTEE pain, function, total scores, and DASH score, respectively (p < 0.001). No tendon ruptures, post-procedural infections, or other complications were noted. CONCLUSION: USPNT with Tenex significantly improves symptoms and function in individuals with LE even with long-term follow-up for 3 years. Post-procedure PT is associated with improved treatment response and should be considered after USPNT.

Assessing Femoral Trochlear Morphologic Features on Cross-Sectional Imaging Before Trochleoplasty: Dejour Classification Versus Quantitative Measurement.

OBJECTIVE. The purpose of this study is to assess the use of cross-sectional imaging to qualitatively and quantitatively categorize trochlear dysplasia as low grade (type A) or high grade (types B-D) according to the Dejour classification. MATERIALS AND METHODS. A retrospective review of CT and MRI knee examinations performed before patients underwent deepening trochleoplasty was independently conducted by two musculoskeletal radiologists. Each case of trochlear dysplasia was qualitatively assigned a Dejour type. Subsequently, quantitative measurements of the sulcus angle, distance from the tibial tubercle to the trochlear groove, trochlear depth, lateral trochlear inclination, trochlear facet asymmetry, and degree of patellar lateralization were performed. RESULTS. A total of 35 patients (29 female patients and six male patients; mean age, 21.1 years) with 39 affected knees (17 right knees and 22 left knees) were included. Readers had exact qualitative agreement using Dejour classification for 30 of 39 knees (77% [κ = 0.77; 95% CI, 0.62-0.91]) and agreement on classification of low-grade versus high-grade dysplasia for 36 of 39 knees (92%). For these 36 knees, the mean differences in measurements of low- versus high-grade dysplasia, respectively, were as follows: for sulcus angle, 153° versus 168° (p < 0.001); for trochlear depth, 4 versus 1 mm (p < 0.001); for lateral trochlear inclination, 12 versus 7 mm (p < 0.02); and for decreased trochlear facet asymmetry, 13% versus 92% (p < 0.001). Trochlear depth, lateral trochlear inclination, and trochlear facet asymmetry were also different in comparisons of knees with Dejour type B and C trochlear dysplasia versus those with Dejour types B and D (all p < 0.05). No quantitative measurement differentiated between trochlear dysplasia of Dejour types C and D. The distance from the tibial tubercle to the trochlear groove and the degree of patellar lateralization were not statistically different between low- and high-grade dysplasia. CONCLUSION. Qualitative use of the Dejour classification accurately categorizes trochlear dysplasia as low grade or high grade in 92% of cases, with exact agreement reached in 77% of cases. Furthermore, the trochlear depth, lateral trochlear inclination, trochlear facet asymmetry, and sulcus angle can differentiate between low-grade and high-grade dysplasia, with trochlear depth, lateral trochlear inclination, and trochlear facet asymmetry useful for differentiating between Dejour types B and C and Dejour types B and D.

Impact of fluoroscopic injection location on immediate and delayed pain relief in patients with greater trochanteric pain syndrome.

OBJECT: The purpose of this study was to assess whether fluoroscopically guided corticosteroid injections into the extrabursal tissues, trochanteric (subgluteus maximus) bursa, or subgluteus medius bursa provide better immediate and short-term pain relief. MATERIALS AND METHODS: All fluoroscopically guided corticosteroid injections performed over a 67-month period for greater trochanteric pain syndrome were retrospectively reviewed. Procedural images were reviewed by two musculoskeletal radiologists to determine the dominant injection site based on final needle positioning and contrast spread pattern, with discrepancies resolved by consensus. Statistical analysis of the association between pain score reduction and dominant injection site was performed. RESULTS: One hundred forty injections in 121 patients met the inclusion criteria. The immediate and 1-week post-injection pain reduction was statistically significant for trochanteric bursa, subgluteus medius bursa, and non-bursal injections. However, there was no statistically significant difference in the degree of pain reduction between the groups. There was statistically significant increase in the 1-week post-injection mean pain score compared with immediate post-injection mean pain score in the subgluteus medius bursa and non-bursal injection groups (p < 0.01) but not in the trochanteric bursa group. CONCLUSION: Fluoroscopy is frequently chosen over blind injection or ultrasound guidance for trochanteric steroid injections in patients with a high body mass index. Our results indicate that fluoroscopically guided steroid injections into the trochanteric bursa and subgluteus medius bursa significantly reduced immediate and 1-week post-injection pain scores, as do non-bursal injections. Steroid injection into the subgluteus medius bursa and non-bursal sites may be less effective in maintaining pain reduction at 1-week post-injection.

Percutaneous image-guided bone biopsy of osteomyelitis in the foot and pelvis has a low impact on guiding antibiotics management: a retrospective analysis of 60 bone biopsies.

OBJECTIVE: Image-guided percutaneous bone biopsy may be requested by clinicians to guide antibiotics management decisions in patients with extremity osteomyelitis. Much of the clinical literature describes a high rate of bone biopsy culture positivity in patients with osteomyelitis, but anecdotally biopsy is felt to be fairly low yield in many musculoskeletal radiology practices. The objective of the study is to determine the culture positivity rate and clinical utility of bone biopsy in guiding the management of patients with osteomyelitis. MATERIALS AND METHODS: All image-guided bone biopsy procedures of the pelvis or foot performed at a single institution were identified by a retrospective report search, and only those with a clinical suspicion for infection were included. Cases were included based on convincing imaging findings of osteomyelitis on retrospective review. Microbiology results were reviewed in the clinical chart, as were antibiotics management decisions and response to antibiotics therapy. RESULTS: A total of 60 bone biopsies met the inclusion criteria, 25 within the foot and 35 biopsies of the pelvis. Overall, 11 out of 60 core biopsies (18%) yielded positive cultures. Antibiotics management was altered in only 27% patients with a positive culture; thus, only 5% of patients with MRI findings of osteomyelitis undergoing biopsy had an impact on management. CONCLUSION: Percutaneous bone biopsies may have a low rate of culture positivity, and even when positive, frequently do not have an impact on antibiotics choice. These data differ from much of the clinical literature, which describes a very high rate of culture positivity.

Spinal blastomycosis: unusual musculoskeletal presentation with literature review.

We report a case of a 41-year-old male who presented to our institution with a large groin mass. CT, MRI and PET imaging was performed and was concerning for a soft tissue abscess likely originating in the lumbar spine. Differential considerations included infection, with atypical infections such as tuberculosis strongly considered. Biopsy revealed fungal elements preliminarily reported as consistent with Cryptococcus neoformans but later revealed to be Blastomyces dermatitidis. The patient responded positively following the introduction of appropriate treatment. This case illustrates the imaging similarities between spinal blastomycosis, spinal tuberculosis, and other fungal infections as well as the need for biopsy to differentiate.

Incidence of gadolinium or fluid signal within surgically proven glenoid labral tears at MR arthrography.

OBJECTIVE: To determine how often patients with surgically proven labral tears have labral signal on shoulder MR arthrography (MRA) that is not equal to gadolinium or fluid on T1- and T2-weighted images, respectively. MATERIALS AND METHODS: Consecutive patients with surgical repair of a SLAP or Bankart labral tear within 95 days of an MRA were included. Using cartilage signal as an internal reference, two musculoskeletal (MSK) radiologists retrospectively categorized labral signal as T1-hyperintense, T1-gadolinium, T2-hyperintense, or T2-fluid. In patients without T1-gadolinium or T2-fluid labral signal, secondary findings such as the orientation, extent, shape, and width of the abnormal signal was recorded. Statistical analyses were performed using Fisher's test and ANOVA. RESULTS: Sixty-one labral tears (36 SLAP and 25 Bankart) in 54 patients (mean age, 30.7; F:M 8:46) met the inclusion criteria. In 67% and 76% of SLAP and Bankart labral tears, T1-gadolinium signal was present (p = 0.43). T2-fluid signal was present in 50% and 92% of these same labral tears (p = 0.001). The absence of T1-gadolinium or T2-fluid signal was more common in SLAP tears (33%) compared to Bankart tears (8%) (p = 0.02). In the SLAP cases, at least two secondary findings of a SLAP tear were present in 92% (11/12). CONCLUSIONS: Lack of surfacing T1-gadolinium or T2-fluid labral signal is unusual in Bankart tears but relatively common in SLAP tears. However, a SLAP tear was diagnosed in 92% of these 12 cases when two secondary findings were present.

Spinal Hematomas: What a Radiologist Needs to Know.

Spinal hematomas are a frequent indication for radiologic evaluation and can be a diagnostic dilemma for many radiologists and surgeons. There are four types of spinal hematomas: epidural, subdural, subarachnoid, and intramedullary (spinal cord) hematomas. Because they differ by their location in relationship to the meningeal membranes and spinal cord, unique radiologic appearances can be recognized to distinguish these types of spinal hemorrhage. Anatomic knowledge of the spinal compartments is essential to the radiologist for confident imaging diagnosis of spinal hematomas and to specify correct locations. MRI is the modality of choice to diagnose the location of the hematoma, characterize important features such as age of the hemorrhage, and detect associated injury or disease. Each type of spinal hematoma has imaging patterns and characteristics that distinguish it from the others, as these specific spinal compartments displace and affect the adjacent anatomic structures. Early detection and accurate localization of spinal hematomas is critical for the surgeon to address the proper treatment and surgical decompression, when necessary, as neurologic deficits may otherwise become permanent. Online supplemental material is available for this article. ©RSNA, 2018.

Magnetic resonance imaging of the knee: An overview and update of conventional and state of the art imaging.

Magnetic resonance imaging (MRI) has become the preferred modality for imaging the knee to show pathology and guide patient management and treatment. The knee is one of the most frequently injured joints, and knee pain is a pervasive difficulty that can affect all age groups. Due to the diverse pathology, complex anatomy, and a myriad of injury mechanisms of the knee, the MRI knee protocol and sequences should ensure detection of both soft tissue and osseous structures in detail and with accuracy. The knowledge of knee anatomy and the normal or injured MRI appearance of these key structures are critical for precise diagnosis. Advances in MRI technology provide the imaging necessary to obtain high-resolution images to evaluate menisci, ligaments, and tendons. Furthermore, recent advances in MRI techniques allow for improved imaging in the postoperative knee and metal artifact reduction, tumor imaging, cartilage evaluation, and visualization of nerves. As treatment and operative management techniques evolve, understanding the correct application of these advancements in MRI of the knee will prove to be valuable to clinical practice. LEVEL OF EVIDENCE: 5 J. MAGN. RESON. IMAGING 2017;45:1257-1275.

Fluoroscopically Guided Sacroiliac Joint Injections: Comparison of the Effects of Intraarticular and Periarticular Injections on Immediate and Short-Term Pain Relief.

OBJECTIVE: The purpose of this study was to determine whether intraarticular sacroiliac joint injections provide greater immediate and short-term pain relief than periarticular sacroiliac joint injections do. MATERIALS AND METHODS: The records of all fluoroscopically guided sacroiliac joint injections performed over a 4-year period were identified. Patients who received an injection of 0.5 mL of bupivacaine and 0.5 mL (20 mg) of triamcinolone and who had preinjection, immediate, and 1-week postinjection pain scores (0-10 numeric scale) were included. Images from the procedures were retrospectively reviewed by two musculoskeletal radiologists to determine intraarticular or periarticular administration of the injection with discrepancies resolved by consensus. RESULTS: One hundred thirteen injections in 99 patients (65 women, 34 men; mean age, 59.4 years) met the inclusion criteria. There were 55 intraarticular and 58 periarticular injections. The mean preinjection, immediate, and 1-week postinjection pain scores for the intraarticular injections were 6.0, 1.6, and 4.1 and for the periarticular injections were 6.1, 2.0, and 4.2. The mean immediate and 1-week postinjection pain reduction were statistically significant in both groups (p < 0.001). After adjustment for age, sex, preinjection pain score, time of year, and indication for injection, no significant difference in the preinjection to immediately postinjection change in pain between intraarticular and periarticular injections (mean change, 0.37; p = 0.319) or in the preinjection to 1-week postinjection change in pain (mean change, 0.06; p = 0.888) was noted. The mean fluoroscopy times were 42.4 seconds for intraarticular injections and 60.5 seconds for periarticular injections (p = 0.32). CONCLUSION: Although both intraarticular and periarticular sacroiliac joint injections provide statistically significant immediate and 1-week postinjection pain relief, no significant difference in the degree of pain relief achieved with intraarticular and periarticular injections was noted.

High-Resolution MR Imaging and US Anatomy of the Thumb.

Despite having many unique anatomic features relative to the other digits, the thumb has received little attention in the radiology literature. The thumb, with its opposable and prehensile abilities, enables fine manual dexterity. However, most radiologists have little familiarity with the structures that allow these dynamic movements, other than their recognition of the role of the ulnar collateral ligament in the setting of gamekeeper injury. High-resolution magnetic resonance (MR) imaging allows optimal assessment of the intricate soft-tissue anatomy of the thumb, which enables thumb flexion, extension, abduction, and adduction. Ultrasonography is a readily available, inexpensive tool that can supplement MR imaging in the evaluation of juxta-articular soft-tissue anatomy. Both imaging modalities are extremely useful for identifying the key ligaments responsible for stabilizing the first carpometacarpal and metacarpophalangeal joints. MR imaging is particularly important in assessment of these ligaments in both normal and trauma settings, which is essential for not only recognizing acute injuries but also becoming familiar with the morphologic variations that are potential pitfalls. To accurately and confidently diagnose abnormalities of these small soft-tissue structures, radiologists must have a clear understanding of the complexities associated with imaging the normal thumb anatomy. ©RSNA, 2016.

Postoperative Shoulder Imaging: Rotator Cuff, Labrum, and Biceps Tendon.

Imaging interpretation of the postoperative shoulder is a challenging and difficult task for both the radiologist and the orthopedic surgeon. The increasing number of shoulder rotator cuff, labrum, and biceps tendon repairs performed in the United States also makes this task a frequent occurrence. Whether treatment is surgical or conservative, imaging plays a crucial role in patient care. Many imaging findings can be used to predict prognosis and functional outcomes, ultimately affecting treatment. In addition, evolving surgical techniques alter the normal anatomy and imaging appearance of the shoulder such that accepted findings proved to be pathologic in the preoperative setting cannot be as readily described as pathologic after surgery. An understanding of common surgical procedures of the shoulder can aid in recognizing normal expected postoperative findings and discerning common complications. Although magnetic resonance (MR) imaging and MR arthrography are widely used, implementing a multimodality imaging approach for evaluation of the postoperative shoulder can provide additional imaging information that may be decisive and vital to diagnosis. The high spatial resolution of both computed tomography with arthrography and ultrasonography makes them additional modalities to consider, especially when dealing with metal artifact. To provide an accurate radiologic interpretation of high clinical value, radiologists should approach the postoperative shoulder comprehensively with knowledge of the anatomy, surgical techniques and complications, clinical outcomes, and imaging pitfalls. ©RSNA, 2016.

Accuracy and efficacy of fluoroscopy-guided pars interarticularis injections on immediate and short-term pain relief.

PURPOSE: To determine the accuracy and short-term efficacy of fluoroscopy-guided steroid/anesthetic injections for symptomatic pars interarticularis (pars) defects. MATERIALS AND METHODS: Following IRB approval, all fluoroscopically guided pars injections from a single institution (6/2010 to 3/2016) were retrospectively and independently reviewed by two MSK radiologists. The radiologists evaluated the fluoroscopic images to determine if all of the pars injections associated with each procedure were intra-pars (n = 57 procedures; 106 pars injections), peri-pars (n = 3 procedures; three pars injected), or a combination of intra-pars and peri-pars (n = 6 procedures; 12 pars injected). The patients were asked their pain score (graded on a scale of 0-10) pre-injection, 5-10 min and 1-week post-injection. Age, gender, and fluoroscopic times were recorded. Statistical analysis was performed on the all intra-pars injections only. RESULTS: Exact inter-reader agreement was present in 92 % (112/121) of the injections, with 57 of the procedures (106 pars injections) performed on 41 patients (mean age 36; 18 M, 23 F) all intra-pars. The mean pre-injection and 5-10 min post-injection reduction in pain for the all intra-pars injections was -3.0 units (95 % CI: [-3.9, -2.1] units; p < 0.001) with a mean 1-week post-injection (n = 21 procedures; 38 pars) reduction in pain of -0.7 units (95 % CI [-1.5, 0.0]; p = 0.06). The geometric mean fluoroscopic time per pars injected was 42 s. CONCLUSIONS: Over 92 % of fluoroscopically guided injections for symptomatic spondylolysis are technically successful with minimum fluoroscopic time, resulting in statistically significant pain reduction immediately post-injection and a trend in pain reduction 1-week post-injection.

Stress Imaging of Bone.

This article defines stress injury, including insufficiency and fatigue fractures. The pathophysiology and risk factors for development of stress injuries are also discussed. The most common locations, including specific imaging examples, are reviewed with an emphasis on early detection and differentiation of high-risk and low-risk locations. Optimal imaging modalities with associated imaging findings are covered, as well as some potential pitfalls to avoid. The importance of correlating imaging findings with symptoms and the prognostic value of imaging grading are also discussed.

Inadvertent intraosseous injection during fluoroscopy-guided joint injection of two adult patients.

Two cases of inadvertent intraosseous injection during fluoroscopy-guided joint injection are presented. The first case occurred during a pre-MRI hip arthrogram while the second case happened during a glenohumeral joint steroid injection. Both cases were performed on osteopenic female patients over 60 years old who reported significant pain during injection of contrast and fluoroscopic imaging showed pooling of contrast in bone during attempted injection. Both procedures were corrected by retracting the needle to achieve intraarticular injection. Being aware of intraosseous injection as a possible reason for difficulty during the procedure both guides the operator to proper correction (retraction of the needle) and also avoids a non-diagnostic or less effective procedure.

MRI and Arthroscopic Correlation of the Wrist.

Since its introduction in 1979, the practice of and indications for wrist arthroscopy in the diagnosis and treatment of pathologic conditions in the wrist continues to grow. Magnetic resonance imaging (MRI) is another commonly used tool to noninvasively examine the anatomy and pathology of the wrist joint. Here, we review the normal wrist anatomy as seen arthroscopically and through MRI. We then examine the various common pathologic entities and define both the arthroscopic findings and correlated MRI findings in each of these states.

Spinal subdural abscess following repeat lumbar microdiscectomy: A case report of imaging findings for a rare infection.

Spinal subdural abscess is a rare central nervous system infection with just over a hundred cases reported. It is much less common than spinal epidural abscess. While most case reports have focused on route of infection and treatment options, there have not been any reports that focused on the unique MRI findings of spinal subdural abscess. We describe a case of spinal subdural abscess diagnosed by MRI in a 33-year-old male who presented with headaches after undergoing a microdiscectomy procedure, and review the underlying anatomic features of the spinal meninges which produce the appearance of a spinal subdural abscess.