MR Neurography and Quantitative Muscle MRI of Parsonage Turner Syndrome Involving the Long Thoracic Nerve.

BACKGROUND: Parsonage-Turner syndrome (PTS) is characterized by severe, acute upper extremity pain and subsequent paresis and most commonly involves the long thoracic nerve (LTN). While MR neurography (MRN) can detect LTN hourglass-like constrictions (HGCs), quantitative muscle MRI (qMRI) can quantify serratus anterior muscle (SAM) neurogenic changes. PURPOSE/HYPOTHESIS: 1) To characterize qMRI findings in LTN-involved PTS. 2) To investigate associations between qMRI and clinical assessments of HGCs/electromyography (EMG). STUDY TYPE: Prospective. POPULATION: 30 PTS subjects (25 M/5 F, mean/range age = 39/15-67 years) with LTN involvement who underwent bilateral chest wall qMRI and unilateral brachial plexus MRN. FIELD STRENGTH/SEQUENCES: 3.0 Tesla/multiecho spin-echo T2-mapping, diffusion-weighted echo-planar-imaging, multiecho gradient echo. ASSESSMENT: qMRI was performed to obtain T2, muscle diameter fat fraction (FF), and cross-sectional area of the SAM. Clinical reports of MRN and EMG were obtained; from MRN, the number of HGCs; from EMG, SAM measurements of motor unit recruitment levels, fibrillations, and positive sharp waves. qMRI/MRN were performed within 90 days of EMG. EMG was performed on average 185 days from symptom onset (all ≥2 weeks from symptom onset) and 5 days preceding MRI. STATISTICAL TESTS: Paired t-tests were used to compare qMRI measures in the affected SAM versus the contralateral, unaffected side (P < 0.05 deemed statistically significant). Kendall's tau was used to determine associations between qMRI against HGCs and EMG. RESULTS: Relative to the unaffected SAM, the affected SAM had increased T2 (50.42 ± 6.62 vs. 39.09 ± 4.23 msec) and FF (8.45 ± 9.69 vs. 4.03% ± 1.97%), and decreased muscle diameter (74.26 ± 21.54 vs. 88.73 ± 17.61 µm) and cross-sectional area (9.21 ± 3.75 vs. 16.77 ± 6.40 mm2 ). There were weak to negligible associations (tau = -0.229 to <0.001, P = 0.054-1.00) between individual qMRI biomarkers and clinical assessments of HGCs and EMG. DATA CONCLUSION: qMRI changes in the SAM were observed in subjects with PTS involving the LTN. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Outcomes of ultrasound-guided injections of Bennett lesions of the shoulder.

PURPOSE: To describe our technique and short term follow up of ultrasound-guided injections of symptomatic Bennett lesions. METHODS: We performed 13 ultrasound-guided injections in 10 baseball players from August 2014 to August 2021. The cohort was comprised of 10 males, with a mean age of 25 years and 1 month (age range: 17 years, 10 months-33 years, 1 month). Of the 10 patients, 6 were major league baseball players (including 5 pitchers and a second baseman), 3 were minor league baseball pitchers; and 1 pitched in high school. Symptoms in our patients included posterior shoulder pain at rest, pain with pitching (including in the acceleration phase and with follow-through), glenoid internal reduction deficit, and decreased pitching velocity. The procedure was performed in a similar fashion as a standard posterior approach glenohumeral injection, though with the linear transducer positioned slightly more medially. The needle was inserted from a lateral to medial approach, in plane with the transducer and aimed to the superficial surface of the Bennett lesion, onto which anesthetic and steroid was injected, avoiding injection into the glenohumeral joint. RESULTS: All patients had MRIs that showed Bennett lesions and all but one of the sonograms demonstrated the Bennett lesion. In 8/12 (67%) injections, the patient reported varying degrees of immediate symptom relief. In 4/12 injections, patients were unable to assess for immediate postprocedural change in symptomatology and for one patient post-procedural symptomatology was not documented. No complications occurred. Analytics of the average 4-seam fastball velocity was available for 2 of the major league players who had in-season injections, with minimal change in postprocedural velocity in the year after their ultrasound procedure; for one of the pitchers, his fastball velocity slightly increased in the month after the procedure while the other pitcher had his injection towards the end of the season and he threw no fastballs in his final games of the season. Two of the other professional pitchers went on to surgical intervention and neither returned to pitch professionally. CONCLUSION: Injection of symptomatic Bennett lesions is a safe procedure and can provide symptomatic relief that may be temporary, though equivocally useful clinically.

Serial Ultrasonography for the Assessment of Healing of Lower Extremity Bone Stress Injury and Correlation With Return to Sport/Exercise.

BACKGROUND: Lower extremity bone stress injuries (BSIs) are common among athletes who participate in high-impact activities. Conventional imaging is limited in assessing healing of BSIs. HYPOTHESIS: Serial ultrasonography (US) can identify changes in appearance of lower extremity BSIs over time that can be correlated with symptoms and return to exercise/sport. STUDY DESIGN: Cohort observational study. LEVEL OF EVIDENCE: Level 3. METHODS: Adults 18 to 50 years old with a recent exercise-associated BSI of distal tibia/fibula or metatarsals diagnosed by magnetic resonance imaging (MRI) were enrolled. US was performed every 2 weeks for 12 weeks. The sonographic appearance (soft tissue edema, periosteal reaction, hyperemia on power Doppler, callus) was correlated with the numerical rating scale (NRS) for pain and ability to return to sport/exercise. RESULTS: A total of 30 patients were enrolled (mean age, 35.3 ± 7.7 years; 21 [70.0%] female). The tibia was most frequently affected (n = 15, 50.0%), followed by metatarsals (n = 14, 46.7%) and fibula (n = 1, 3.3%). At week 4, 25 of 30 (83.3%) had at least 1 US finding associated with the BSI. The degree of hyperemia was correlated with NRS at weeks 4 and 6 (Spearman correlations [ρ] 0.45 [0.09, 0.69] and 0.42 [0.07, 0.67], respectively), as well as return to sport/exercise at week 6 (ρ -0.45 [-0.68, -0.09]). US soft tissue edema was also correlated with NRS at week 6 (ρ 0.38 [0.02, 0.65]). CONCLUSION: Serial US of lower extremity BSIs can provide objective measures of healing. US findings were correlated with clinical outcomes at multiple timepoints. CLINICAL RELEVANCE: US may have advantages over conventional imaging for monitoring healing of lower extremity BSIs. Further research is needed to better understand the prognostic value of these sonographic indicators of BSI healing and role in assessing readiness for return to sport/exercise.

Osteomyelitis and septic arthritis after Mycobacterium Bovis BCG Therapy for Urinary Bladder Cancer.

Mycobacterium bovis (M. bovis) Bacillus Calmette-Guerin (BCG) - an attenuated strain of M. bovis - is closely related to Mycobacterium tuberculosis and may be used as a vaccine against tuberculosis as well as a treatment for urinary bladder cancer. Complications of M. bovis BCG administration, while rare, can occur. While a few cases of vertebral osteomyelitis secondary to BCG therapy exist in the literature, and while there are case reports of osteomyelitis and septic arthritis from BCG vaccination (Chen et al., 2017; Huang et al., 2019; Lin et al., 2015 [1-3]), there are no reported cases of osteomyelitis and septic arthritis involving the foot from BCG therapy for urinary bladder cancer. We present an unusual presentation of osteomyelitis and septic arthritis of the tarsometatarsal joints after M. bovis BCG therapy for urinary bladder cancer. We will describe MRI and ultrasound findings in our case of M. bovis BCG osteomyelitis and septic arthritis.

Identification of long thoracic nerve on high-resolution 3T MRI.

OBJECTIVE: Long thoracic neuropathy results in serratus anterior muscle denervation and presents with scapular winging. Previously published studies have been unable to identify the long thoracic nerve on MRI; instead, secondary imaging features of serratus anterior muscle denervation are used to infer nerve injury. Our study's purpose was to evaluate the ability of high-resolution MRI to depict the long thoracic nerve. MATERIALS AND METHODS: In this HIPAA-compliant, IRB-approved retrospective study, two musculoskeletal radiologists reviewed the brachial plexus MRI exans of 24 subjects performed for clinical suspicion of long thoracic neuropathy. The radiologists evaluated whether the long thoracic nerve could be identified and for the presence of serratus anterior denervation; when the nerve was seen, assessment for nerve enlargement, signal hyperintensity, and morphologic change was performed. Inter-observer reliability was estimated with Cohen's kappa (κ). Clinical presentation and electromyogram (EMG) were then reviewed. RESULTS: The long thoracic nerve was identified in 18 cases (75%), with high inter-observer reliability for nerve visualization. Kappa values of 1.0, 0.9, 1.0, and 0.9 were obtained for identification of the LTN on coronal sequences of the brachial plexus, identification of the LTN on proximal and mid segments of the nerve on oblique sagittal sequences, and identification of the distal segment of the LTN on axial sequences through the chest, respectively. The nerve was identified in 91% of patients with positive EMG findings for a long thoracic neuropathy. In patients with EMG features of long thoracic neuropathy, 70% had corresponding abnormal MRI features. When denervation edema was present, the nerve was identified 86% of the time. CONCLUSION: High-resolution MRI can be used to visualize segments of the long thoracic nerve.

When the Wave Breaks You: Magnetic Resonance Imaging Findings After Surfing Injuries.

BACKGROUND: There are approximately 2.1 million recreational surfers in the United States. However, little has been reported on surfing-related injuries and, to date, no study has utilized magnetic resonance imaging (MRI) to characterize injury patterns. OBJECTIVE: To use MRI to perform a descriptive analysis of surfing injuries in patients who presented to an urban tertiary care musculoskeletal hospital. This was not a hypothesis-driven study. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: A retrospective review of the picture archiving and communication system as well as the electronic medical record was performed to identify patients with surfing-related injuries who presented to a tertiary care musculoskeletal hospital for treatment. The search included participants over a 10-year period who presented between January 1, 2009, and August 1, 2018. Descriptive data analyses were performed to determine frequency of body part injured, diagnosis, and operative versus nonoperative treatment. RESULTS: The search yielded 109 patients with surfing-related injuries and MRIs. A total of 90 patients presented within 6 months of their surfing injury and were included in the final analysis. The median age was 36 years (range, 12-66 years). A majority of the patients included were male (74%; n = 67). Acute surfing injuries were diagnosed via imaging in 72% (n = 65) of patients. The joints injured most commonly were the shoulder (46%; n = 30) and the knee (28%; n = 18). Only 17% (n = 11) of acute surfing injuries required surgery, while 83% (n = 54) were treated nonoperatively. CONCLUSION: The most common surfing-related injuries occurred in the shoulder and knee. CLINICAL RELEVANCE: This study helps characterize the risk of injury for surfers and informs healthcare providers on common surfing injuries.

Aspiration of sterile post-operative spinal fluid collections using low-dose computed tomography guidance.

Sterile postoperative seromas can develop after posterior spinal surgery and cause pain, weakness, and numbness. Management typically involves operative evacuation. We propose that these collections can be managed with percutaneous computed tomography (CT) guided aspiration, potentially saving the patient an additional surgery. Here, we evaluate the safety and efficacy of this approach. Patients who developed symptomatic postoperative seromas within 60 days following surgery for spinal canal stenosis and had stable neurologic exams were considered for CT-guided percutaneous aspiration. To be considered for this approach, patients had to have pre-procedural evidence of radiographic spinal cord or cauda equina compression, hemodynamic stability, and low suspicion for infection. A total of 16 symptomatic collections were aspirated among 15 patients. The mean volume of fluid removed was 32.0 mL. There were no peri- or post-procedural complications. Eight (50%) had resolution or substantial improvement of their symptoms (p = 0.0002 when compared to the null hypothesis). One patient had short interval improvement but return of their initial symptoms 12 h following aspiration, 3/16 (19%) had minimal improvement, and 4/16 (25%) had no change in symptoms. Fluid collections that appeared denser on the pre-procedural CT were associated with retrieval of more sanguineous appearing fluid (p = 0.08). Neither the amount nor quality of fluid aspirated was associated with outcome. We conclude that percutaneous CT-guided aspiration of postoperative seromas is safe and should be considered as an alternative to open surgical evacuation in patients with stable neurologic exams.

Prevalence of Os Styloideum in National Hockey League Players.

BACKGROUND: Os styloideum describes an accessory carpal ossicle between the trapezoid, the capitate, and the second and third metacarpals. Injuries to this tissue have been described as part of the carpal boss syndrome. While the etiology of os styloideum remains uncertain, it may represent a physiologic response to altered loading forces in the wrist, similar to the development of cam-type deformity in the hips of ice hockey players or the Bennett lesion in the shoulders of baseball pitchers. HYPOTHESIS: Professional hockey players will have a higher prevalence of os styloideum compared with the general population. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: A retrospective review of 16 professional hockey players from 4 different National Hockey League (NHL) teams who underwent unilateral imaging of the wrist was performed. Seventeen wrists were reviewed for the presence of os styloideum. RESULTS: Thirteen of 16 players (81%) had an os styloideum, representing an increased prevalence compared with the general population. Previous clinical and cadaveric studies estimated a general prevalence of up to 19% ( P < 0.001). For the 10 players who had their leading wrist scanned, 9 had an os styloideum (90%). Ten of 11 (91%) players demonstrated a bone marrow edema pattern within the metacarpal and the os styloideum on magnetic resonance imaging. There was no significant association between the presence of an os styloideum and the player's position, leading wrist, or years in the league. CONCLUSION: There appears to be an increased prevalence of os styloideum among NHL players, and team physicians should consider this finding while formulating a differential diagnosis for dorsal wrist pain. CLINICAL RELEVANCE: This study identified NHL players as having an increased prevalence of os styloideum compared with the general population. By doing so, these findings represent an opportunity to enhance our understanding of the etiology, clinical significance, and treatment of os styloideum.