Shear wave elastography demonstrates different material properties between the medial collateral ligament and anterolateral ligament

BACKGROUND

Anterolateral ligament and medial collateral ligament injuries could happen concomitantly with anterior cruciate ligament ruptures. The anterolateral ligament is injured more often than the medial collateral ligament during concomitant anterior cruciate ligament ruptures although it offers less restraint to knee movement. Comparing the material properties of the medial collateral ligament and anterolateral ligament helps improve our understanding of their structure-function relationship and injury risk before the onset of injury.

METHODS

Eight cadaveric lower extremity specimens were prepared and mechanically tested to failure in a laboratory setting using a hydraulic platform. Measurements of surface strains of superficial surface of each medial collateral ligament and anterolateral ligament specimen were found using three-dimensional digital image correlation. Ligament stiffness was found using ultrasound shear-wave elastography. t-tests were used to assess for significant differences in strain, stress, Young's modulus, and stiffness in the two ligaments.

FINDINGS

The medial collateral ligament exhibited greater ultimate failure strain along its longitudinal axis (p = 0.03) and Young's modulus (p < 0.0018) than the anterolateral ligament. Conversely, the anterolateral ligament exhibited greater ultimate failure stress than the medial collateral ligament (p < 0.0001). Medial collateral ligament failure occurred mostly in the proximal aspect of the ligament, while most anterolateral ligament failure occurred in the distal or midsubstance aspect (P = 0.04).

INTERPRETATION

Despite both being ligamentous structures, the medial collateral ligament and anterolateral ligament exhibited separate material properties during ultimate failure testing. The weaker material properties of the anterolateral ligament likely contribute to higher rates of concomitant injury with anterior cruciate ligament ruptures.

Three-Month Complication Rate of Ultrasound-Guided Soft Tissue Surgical Procedures Across Six Sports Medicine Clinics

OBJECTIVES

To 1) determine the types and frequency of complications within 3 months following ultrasound-guided surgical procedures, and 2) identify any patient demographics, co-morbidities, or procedural characteristics that were associated with an increased risk of complications.

METHODS

A retrospective chart review was performed at six Sports Medicine clinics across the United States. The Clavien-Dindo classification was used to categorize procedural complications on a 5-point scale from 1, representing any deviation in post-procedure care without requiring pharmacological or invasive treatment to 5, representing death. Generalized Estimating Equations for binomial outcomes with a logit link were used to estimate the overall and procedure-specific 3-month complication rates.

RESULTS

Among 1902 patients, 8.1% (n = 154) had diabetes and 6.3% (n = 119) were current smokers. The analysis included 2,369 procedures, which were performed in either the upper extremity (44.1%, n = 1045) or lower extremity (55.2%, n = 1308) regions. The most common procedure was ultrasound-guided tenotomy (69.9%, n = 1655). Additional procedures included, trigger finger release (13.1%, n = 310), tendon scraping (8.0%, n = 189), carpal tunnel release (5.4%, n = 128), soft tissue release (2.1%, n = 50), and compartment fasciotomy (1.6%, n = 37). Overall, there was a complication rate of 1.2% (n = 29 complications; 95% CI: 0.8-1.7%). Individual procedures had complication rates that ranged from 0 to 2.7%. There were 13 Grade I complications in 13 patients, 12 Grade II complications in 10 patients, 4 Grade III complications in 4 patients, and 0 Grade IV or V complications. No associations between complication risk and any patient demographics (age, sex, BMI), co-morbidities (diabetes, smoker), or procedure characteristics (type, region) were identified.

CONCLUSION

This retrospective review provides an evidence-based estimate supporting the low level of risk associated with ultrasound-guided surgical procedures for patients from a variety of geographical settings who are seeking care at private and academic-affiliated clinics.

Prevalence of AAV2.5 neutralizing antibodies in synovial fluid and serum of patients with osteoarthritis

Osteoarthritis (OA) is a leading cause of disability with no cure and only supportive therapy. Adeno-associated virus (AAV) serotype 2.5 is being used in a Phase I clinical trial to deliver the interleukin-1 receptor antagonist into knee joints with OA. Neutralizing antibodies (Nab) directed against AAV2.5, if present, could inhibit gene transfer. Here, we report the prevalence of AAV2.5 Nab in the sera and synovial fluids of patients with OA. Nab titers were measured by their ability to inhibit in vitro transduction by AAV2.5 encoding GFP. Of 44 synovial fluids from patients with mid-stage and advanced OA, 43% had undetectable Nab; 25% had low titers (<1:100), 16% had medium titers (1:100-1:1000) and 16% had high titers (>1:1000) of Nab. Titers of AAV2.5 Nabs correlated with those of AAV2, but not with those of AAV5. Serum titers of AAV2.5 Nab correlated positively with titers in synovial fluid, and were never less than the matched synovial fluid titers. These findings suggest that high titers of Nab against AAV2.5 are uncommon in the synovial fluids of patients with OA, and individuals with high synovial fluid Nab titers can be identified by measuring titers in the serum.

Platelet-rich plasma injection for thumb carpometacarpal joint osteoarthritis

Objective

To assess the effects of platelet-rich plasma (PRP) injection among patients with thumb carpometacarpal (CMC) joint osteoarthritis (OA).

Design

Retrospective chart review with follow-up questionnaires/surveys. Post-procedure, patients were sent standardized, automatically-generated follow-up questionnaires, and contacted for a survey regarding patient-reported outcomes.

Setting

Single institution (tertiary care hospital) outpatient clinic from 2015 to 2020.

Participants

Nineteen adult patients (9 women; average age 65.0 [±6.3 years]) who received a PRP injection for OA of 1 or both thumb CMCs (N=19).

Interventions

Platelet-rich plasma injection.

Main Outcome Measures

Outcome measures included symptom improvement (subjective, visual analog scale), duration of benefit, subsequent procedures, satisfaction, and side effects/adverse events. Cellular composition of whole blood and PRP injectate (platelets, erythrocytes, leukocytes, neutrophils, lymphocytes, and monocytes) were analyzed.

Results

Subjects reported moderate or excellent symptom improvement in 68.8% of injected joints and were moderately or very satisfied with 68.8% of the procedures. Mean patient-reported duration of benefit was 15.6 months (±19.5) months (mean duration of follow-up: 32.4 [±18.1] months). There were no major complications attributed to the procedures, but 1 patient was diagnosed with presumed unrelated lymphoma 2 weeks post-procedure. PRP mean platelet concentration was 1787.77 (±687.14) × 10⁹/L, resulting in a mean platelet concentration factor of 8.80 (±4.19) times baseline and mean platelet dose of 1881 × 10⁶. Other PRP cell concentration factors were erythrocytes, 0.02; neutrophils, 0.14; lymphocytes, 3.76; and monocytes, 3.29.

Conclusions

PRP injection appears to be a safe and potentially effective treatment option for pain related to first CMC OA. Further study is needed to optimize treatment protocols and better understand which patients are most likely to benefit.

Traumatic rupture of the midportion of the interosseous membrane: a rare cause of acute lower leg pain in two soccer players kicked in the anterior shin

The interosseous membrane (IOM) of the leg is a component of the tibiofibular syndesmosis that serves an important role in stabilization, as well as transferring forces to the fibula during weight-bearing. We present two separate cases of acute traumatic rupture of the midportion of the interosseous membrane in high school soccer players with blunt trauma to the anterior shin with MRI and ultrasound confirmation.

Does proximal versus distal injury location of the medial ulnar collateral ligament of the elbow differentially impact elbow stability? An ultrasound-guided and robot-assisted biomechanical study

BACKGROUND

The location (proximal vs. distal) of elbow medial ulnar collateral ligament (MUCL) tears impacts clinical outcomes of nonoperative treatment. The purposes of our study were to (1) determine whether selective releases of the MUCL could be performed under ultrasound (US) guidance without disrupting overlying soft tissues, (2) assess the difference in medial elbow stability for proximal and distal releases of the MUCL using stress US and a robotic testing device, and (3) elucidate the flexion angle that resulted in the greatest amount of medial elbow laxity after MUCL injury.

METHODS

Sixteen paired, fresh-frozen elbow specimens were used. Valgus laxity was evaluated with both US and robotic-assisted measurements before and after selective MUCL releases. A percutaneous US-guided technique was used to perform proximal MUCL releases in 8 elbows and to perform distal MUCL releases in their matched pairs. The robot was used to determine the elbow flexion angle at which the maximum valgus displacement occurred for both proximally and distally released specimens. Open dissection was then performed to assess the accuracy of the percutaneous releases.

RESULTS

Percutaneous US-guided releases were successfully performed in 15 of 16 specimens. The proximal release resulted in greater valgus angle displacement (11° ± 2°) than the distal release (8° ± 2°) between flexion angles of 30° and 70° (P < .0001 at 30°, P < .0001 at 40°, P = .001 at 50°, P = .005 at 60°, and P = .020 at 70°). Valgus displacement between release locations did not reach the level of statistical significance between 80° and 120° (P = .051 at 80°, P = .131 at 90°, P = .245 at 100°, P = .400 at 110°, and P = .532 at 120°). When we compared the values for the mean increase in US delta gap (stressed - supported state) from before to after MUCL release, the proximally released elbows had larger increases than the distally released elbows (5.0 mm proximal vs. 3.7 mm distal, P = .032). After MUCL release, maximum mean valgus displacement occurred at 49° of flexion.

CONCLUSIONS

US-guided selective releases of the MUCL can be performed reliably without violating the overlying musculature. Valgus instability is not of greater magnitude for distal releases when compared with proximal releases. This findings suggests there must be alternative factors to explain the difference in clinical prognosis between distal and proximal tears. The observed flexion angle for maximum valgus laxity could have important implications for elbow positioning during US or fluoroscopic stress examination, as well as surgical repair or reconstruction of the MUCL.

Prospective, Single-blind, Randomized Controlled Trial to Evaluate the Effectiveness of a Digital Exercise Therapy Application Compared With Conventional Physical Therapy for the Treatment of Nonoperative Knee Conditions

Objective

To evaluate the effectiveness and adherence of a home exercise therapy program using a digital exercise therapy application (DETA) compared with conventional physical therapy (PT).

Design

Parallel group, randomized controlled trial.

Setting

Two clinics in a tertiary care academic center.

Participants

Participants (N=60) were enrolled within 1 week after a provider visit for knee pain. Inclusion criteria: age 18-75 years, knee pain diagnosis, and clinician-prescribed PT.

Interventions

Participants were randomized to complete either an 8-week intervention of conventional PT (enrolled n=29; complete n=26) or the DETA (enrolled n=31; completed n=24).

Main Outcome Measures

Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference (PI) and Physical Function (PF) scores implemented via computer adaptive tests; number of exercise sessions completed per week (adherence).

Results

Compared with the PT group, the DETA group reported significant decreases in PROMIS-PI scores (−6.1±6.7 vs −1.5±6.6, P<.05, d=0.78) and increases in PROMIS-PF scores (6.0±6.6 vs −0.8±5.8, P<.01, d=0.89) after 8 weeks. No group differences in adherence were observed (P>.05).

Conclusions

Use of this DETA resulted in greater pain and functional improvements compared with PT, with no differences in adherence. It is possible this application may be a viable alternative to conventional PT in certain cases. A larger sample from various geographic locations is needed to improve generalizability and for subgroup analysis. Further investigation is warranted to determine the factors responsible for the differences observed between the groups.

Local Anesthesia Prior to Ultrasound-Guided Hip Joint Injections: A Double-Blind Randomized Controlled Trial of Bacteriostatic Saline versus Buffered Lidocaine

BACKGROUND

Ultrasound (US)-guided hip joint injections are commonly performed for patients with suspected or known intra-articular hip pain. Lidocaine is a well-established local anesthetic used prior to hip joint injections, but it is often associated with discomfort during infiltration. Bacteriostatic saline is an alternative local anesthetic that has been shown to be less painful during infiltration for superficial injections.

OBJECTIVE

To compare infiltrative pain and anesthetic efficacy of bacteriostatic saline (0.9% benzyl alcohol) with a standard local anesthetic (buffered 1% lidocaine) used for local anesthesia prior to US-guided intra-articular hip corticosteroid injections.

DESIGN

Double-blinded, randomized controlled trial.

SETTING

Tertiary care medical center.

PARTICIPANTS

Sixty eight patients age 18-80 (mean 54.8) years referred for US-guided intra-articular hip corticosteroid injections.

INTERVENTION

Patients were randomized to receive a US-guided hip joint corticosteroid injection using either bacteriostatic saline or buffered 1% lidocaine for preinjection local anesthesia.

MAIN OUTCOME MEASURES

Visual Analog Scale (VAS) for pain (0-100) during local anesthetic infiltration as well as during the intra-articular injection. Adverse events were also recorded.

RESULTS

There were no significant differences between bacteriostatic saline and buffered lidocaine with respect to pain during local anesthetic infiltration or during the subsequent intra-articular injection. Pain VAS during local anesthetic infiltration was 13.2 (95% confidence interval [CI] 7.8, 18.5) in the bacteriostatic saline group and 14.0 (95% CI 9.4, 18.5) in the buffered 1% lidocaine group (P = .82). Furthermore, pain VAS during the intra-articular injection was 20.7 (95% CI 14.1, 27.3) in the bacteriostatic saline group and 15.7 (95% CI 10.9, 20.3) in the buffered 1% lidocaine group (P = .57). No adverse events occurred.

CONCLUSIONS

Bacteriostatic saline is a safe and comparably effective alternative to buffered 1% lidocaine for local anesthesia before US-guided hip joint injections and may be considered for subcutaneous/periarticular anesthesia during similar musculoskeletal procedures.

The Difference in Medial Meniscal Extrusion between Non-Weight-Bearing and Weight-Bearing Positions in People with and without Medial Compartment Knee Osteoarthritis

BACKGROUND

Medial meniscal extrusion (MME) has been correlated with medial meniscal injury and progression of medial knee osteoarthritis (OA).

OBJECTIVE

To examine the difference in MME between non-weight-bearing (supine) and weight-bearing (standing) positions in patients with and without medial knee OA. Determine the correlation between body mass index (BMI), Kellgren-Lawrence (KL) grade, Knee Osteoarthritis Outcome Score (KOOS), and MME.

DESIGN

Prospective.

SETTING

Tertiary institution PM&R Department.

PARTICIPANTS

Forty five participants (29 female, 16 male), 24 with healthy knees and 21 with OA.

METHODS OR INTERVENTIONS

A single physician sonographer measured supine and standing MME with ultrasound (US) on each participant. The physician was blinded to all measurements. BMI was recorded on all participants. KL grades and KOOS questionnaires were obtained for the OA group.

MAIN OUTCOME MEASURES

MME in supine and standing positions, change in MME from supine to standing, BMI, KL grade, and KOOS subscale scores.

RESULTS

MME increased .52 mm from supine to standing (P < .001). MME was greater in the OA group in both the supine (P = .002) and standing (P < .001) positions. Increasing BMI was moderately correlated with increasing MME (supine P = .001, standing <.001). Increasing age was correlated with increasing MME (supine P = .012, standing P = .002). Increasing KL grade (from 1 to 4) was correlated with increasing MME (supine P = .015, standing = .006). There was a small-to-moderate correlation between KOOS activities of daily living (ADL) subscale score and change in MME from supine to standing (P = .035). The change in MME from supine to standing positions had a small-to-moderate correlation (P = .035) with KOOS ADL subscale score alone but did not correlate with any of the other KOOS subscale scores or KOOS total scores. Receiver operating characteristic curve analysis suggested a standing MME value of 4.2 mm provides a positive likelihood ratio of 6.02 for knee OA.

CONCLUSIONS

MME is greater in those with OA and with weight-bearing. MME correlates with BMI, age, KL grade, and the KOOS ADL subscale score. Finally, standing MME of 4.2 mm yielded a higher positive likelihood ratio to differentiate between healthy knees and those with medial compartment OA than the previously reported value of 3.0 mm.

Ultrasound-Guided Iliopsoas Tendon Release: A Cadaveric Investigation

BACKGROUND

The iliopsoas is a common source of anterior hip pain. Refractory cases may require surgical intervention, with reported complication rates ranging from 3% to 50%. Development of a minimally invasive, outpatient method of iliopsoas tendon release is desirable and may reduce costs, lower complications, and improve recovery time.

OBJECTIVE

To describe and evaluate the safety and reproducibility of an ultrasound-guided (USG) iliopsoas tendon release using a spinal needle in a cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Academic Institution Procedural Skills Laboratory.

PARTICIPANTS

Five unembalmed cadaveric specimens (three female, two male), 69 to 93 years of age (mean 83.2 years), with a mean body mass index (BMI) of 24.5 kg/m² (range 19.2 to 30.3 kg/m² ).

INTERVENTIONS

Two operators each performed five USG iliopsoas tendon releases. Three additional investigators dissected the pelves to assess completeness of tendon release and damage to adjacent structures.

MAIN OUTCOME MEASURES

Successful transection, completeness (%) of the tendon transection, damage to adjacent structures, and procedural time.

RESULTS

Nine of 10 releases achieved the target release of ≥75% tendon transection. One procedure achieved 50% tendon release. No injury to adjacent structures was identified. The mean duration of the procedure was 6.19 minutes.

CONCLUSIONS

USG iliopsoas tendon release can be performed in a cadaveric model, consistently achieve the desired percentage of tendon release, does not result in injury to adjacent neurovascular structures, and takes approximately 6 minutes to perform. Although results cannot be generalized to a clinical setting, due to the minimally invasive nature of the procedure, it is likely that this procedure can be performed safely in an outpatient setting under local anesthesia, will cost less, and will facilitate a more rapid recovery when compared to standard surgical procedures. Further research is warranted for clinical application.

Sonoanatomy and Pathology of the Gluteus Minimus Tendon

Gluteus minimus disorders are a potential source of greater trochanteric or anterior hip pain. Disorders of the gluteus minimus tendon most commonly occur in conjunction with gluteus medius tendon abnormalities but can also occur in isolation. Understanding the sonoanatomy of the gluteus minimus muscle-tendon unit is a prerequisite for recognizing and characterizing gluteus minimus tendon disorders, which, in turn, guides treatment for patients with greater trochanteric or anterior hip pain syndromes.

Ultrasound Assessment of Weight-Bearing and Non-Weight-Bearing Meniscal Extrusion: A Reliability Study

BACKGROUND

Ultrasound has become a useful instrument in evaluating musculoskeletal pathology. Recent studies suggest that ultrasound imaging of weight-bearing menisci may enhance the assessment of knee pathology, such as osteoarthritis (OA) and meniscal injuries.

OBJECTIVE

The primary aim of this study was to determine the intrarater and interrater reliability of ultrasound measurements of medial meniscal extrusion (MME) after a brief training session.

DESIGN

Prospective reliability study.

SETTING

Physical medicine and rehabilitation (PM&R) department within a tertiary care institution.

PARTICIPANTS

Forty-five participants (29 female, 16 male) were recruited to serve as models, 24 of whom had healthy knees and 21 of whom had radiographically confirmed medial compartment knee OA. Three physician sonographers (1 = experienced, 1 = sports medicine fellow, 1 = post-graduate year [PGY]-4 PM&R resident) were recruited to serve as operators.

METHODS OR INTERVENTIONS

Operators received a brief training session on identifying and measuring MME. All operators measured bilateral MME in each model in the standing and supine positions on two separate days. Operators were blinded to all measurements.

MAIN OUTCOME MEASUREMENTS

Primary outcomes were inter- and intrarater intraclass correlation coefficients (ICCs) of MME measurements among operators with different levels of ultrasound experience.

RESULTS

Supine MME intrarater reliability ICCs were 0.927, 0.885, and 0.780 for the experienced physician, sports medicine fellow, and PGY-4 operators, respectively. Standing MME intrarater reliability ICCs were 0.941, 0.902, and 0.824 for the experienced physician, sports medicine fellow, and PGY-4 operators, respectively. Interrater reliability ICCs were 0.896 and 0.842 for supine and standing measurements, respectively. There was a statistically significant increase in intrarater reliability with experience between the PGY-4 resident and experienced physician operators.

CONCLUSIONS

Operators with different levels of ultrasound experience demonstrated good MME measurement intra- and interrater reliabilities in both supine and standing positions.

Sonographically Guided Plantaris Tendon Release: A Cadaveric Validation Study

BACKGROUND

The plantaris tendon (PT) has been implicated in the pathogenesis of symptoms in a subset of patients with Achilles region pain syndromes and traditionally has been managed via open surgical resection. Although the PT can be visualized on ultrasound, a minimally invasive technique for sonographically guided PT release has not been formally described.

OBJECTIVE

To validate a technique to perform sonographically guided PT release in an unembalmed cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Twenty unembalmed cadaveric knee-ankle-foot specimens (10 right, 10 left) obtained from 16 donors (6 male, 10 female) ages 55-96 years (mean 82.6 years) with body mass indexes of 14.1-33.2 kg/m² (mean 23.3 kg/m² ).

METHODS

After simulated local anesthesia and sonographically guided hydrodissection of the plantaris tendon-Achilles tendon interval, a single experienced operator performed sonographically guided PT release on each specimen using an in-plane, lateral-to-medial approach, a commercially available, disposable 3.0-mm hook knife, and either a 17-5 MHz or 15-7 MHz linear array transducer. Each specimen was subsequently dissected to assess for PT release and iatrogenic injury.

MAIN OUTCOME

Status of the PT, Achilles tendon, and regional neurovascular structures as determined by dissection.

RESULTS

All 20 PT releases were completed in a single attempt through a 3- to 5-mm incision. Dissection confirmed complete PT release in all specimens without damage to the adjacent Achilles tendon or regional neurovascular structures.

CONCLUSION

Sonographically guided PT release is technically feasible and can be performed while avoiding injury to the Achilles tendon and regional neurovascular structures. Additional research is warranted to further define the role of sonographically guided PT release in patients with suspected PT-mediated Achilles region pain syndromes.

LEVEL OF EVIDENCE

IV.

Human Adipose-Derived Mesenchymal Stromal/Stem Cells Remain Viable and Metabolically Active Following Needle Passage

OBJECTIVE

To assess the biological effects of passage through clinically relevant needles on the viability and metabolic activity of culture-expanded, human adipose tissue-derived mesenchymal stromal/stem cells (AMSCs).

DESIGN

Prospective observational pilot study.

SETTING

Academic medical center.

PARTICIPANTS

Patient-derived clinical-grade culture expanded AMSCs.

INTERVENTIONS

AMSCs were passed through syringes without a needle attached (control), with an 18-gauge (25.4-mm) needle attached and with a 30-gauge (19-mm) needle attached at a constant injection flow rate and constant cell concentrations. Each injection condition was completed in triplicate.

MAIN OUTCOME MEASURES

Cell number and viability, proliferative capacity, metabolic activity, and acute gene expression as measured by cell counts, mitochondrial activity, and quantitative real time reverse-transcription polymerase chain reaction on day 0 (immediately), day 1, and day 4 after injection.

RESULTS

AMSC viability was not significantly affected by injection, and cells proliferated normally regardless of study group. Postinjection, AMSCs robustly expressed both proliferation markers and extracellular matrix proteins. Stress-response mRNAs were markedly but transiently increased independently of needle size within the first day in culture postinjection.

CONCLUSIONS

Human, culture-expanded AMSCs maintain their viability, proliferative capacity, and metabolic function following passage through needles as small as 30-gauge at constant flow rates of 4 mL/min, despite an early, nonspecific stress/cytoprotective response. These initial findings suggest that culture-expanded AMSCs should tolerate the injection process during most cell-based therapeutic interventions.

Inflammatory Myopathy Causing Leg Pain in a Soccer Player: Case Report and Return-to-Play Considerations

Leg pain is a common condition in athletes as well as in the general population, and has a broad differential diagnosis that includes musculoskeletal, vascular, rheumatologic, and neurologic etiologies. Idiopathic inflammatory myopathy (IM) is a relatively uncommon but recognized etiology of leg pain. In this case, we describe an acute presentation of IM in an athlete resulting in leg pain and activity limitation. The available literature suggests that moderate-intensity exercise is safe and beneficial in idiopathic IM, but studies to date have not assessed the effects of high-intensity exercise in IM or provided recommendations for return to competitive contact sport in this population.

Optimal Elbow Angle for Sonographic Visualization of the Ulnar Collateral Ligament

OBJECTIVE

To formally examine the sonographic appearance of the elbow ulnar collateral ligament (UCL) at 30° versus 70° of elbow flexion in asymptomatic baseball pitchers.

DESIGN

A prospective, cross-sectional design.

SETTING

Sports medicine clinic in a tertiary academic medical center.

PARTICIPANTS

Thirty asymptomatic adolescent baseball pitchers 13-18 years of age (mean 15.8 years), with at least 3 years of continuous pitching experience and no significant history of elbow pain or injury.

METHODS

Static sonographic images of the bilateral UCLs were obtained at 30° and 70° of elbow flexion by a single experienced examiner. Images were anonymized and randomized into a slide set. Three clinicians with different levels of ultrasound experience reviewed the static 30° and 70° images for each elbow and chose their preferred image based on UCL conspicuity. The clinicians reviewed a re-randomized slide set 1 week later. A different study co-investigator measured UCL cross-sectional area (CSA) on all images using ultrasound machine electronic calipers.

MAIN OUTCOME MEASURES

Preference for the sonographic conspicuity of the UCL at 30° versus 70° of elbow flexion, and UCL CSA at 30° versus 70° of flexion.

RESULTS

Each clinician demonstrated a significant preference for UCL images obtained at 70° of flexion when compared to those obtained at 30° (80.3% overall preference for 70°, P < .001). There was no statistically significant effect of clinician experience or arm dominance on image preference. The sonographically determined CSA of the UCLs were on average 1.4 mm(2) greater at 70° than at 30° of flexion (P < .001) when combining dominant and nondominant arms.

CONCLUSIONS

Static sonographic evaluation of the UCL at 70° of elbow flexion should be integrated into UCL imaging protocols. Furthermore, when performing sonographically guided procedures targeting the UCL, clinicians should consider positioning the elbow at >30° of flexion to optimize UCL conspicuity and CSA.

Variability of the Ischiofemoral Space Relative to Femur Position: An Ultrasound Study

BACKGROUND

Ischiofemoral impingement is caused by compression of the quadratus femoris muscle between the ischial tuberosity and lesser trochanter. The evaluation of ischiofemoral impingement includes radiologic studies to evaluate the ischiofemoral space dimensions. No prior study has evaluated the effect of femoral position on ischiofemoral space dimensions.

OBJECTIVE

To determine whether the dimensions of the ischiofemoral space vary with changes in femoral position.

DESIGN

Cross-sectional study.

SETTING

Academic institution.

PARTICIPANTS

Six male and four female subjects with no hip pain and no history of hip disorders or surgery were selected to participate in the study. The subjects' mean age was 31.5 years; mean height, 176.8 cm; mean weight, 70.2 kg; and mean body mass index, 23.6 kg/m(2).

METHODS

Ultrasound was used to measure the ischiofemoral space in bilateral gluteal regions of each volunteer. The volunteers underwent imaging in a prone position. The ischiofemoral space was measured with the femur in 9 different positions created through various combinations of frontal (15° abduction, neutral, and 15° adduction) and transverse (30° internal rotation, neutral, and 30° external rotation) plane hip motions.

MAIN OUTCOME MEASUREMENTS

The narrowest ischiofemoral interval, defined as the narrowest distance between the medial cortex of the lesser trochanter and the lateral cortex of the ischial tuberosity.

RESULTS

The anatomic landmarks used to measure the ischiofemoral space were easily identified in all subjects. The frontal plane main effect (F2,18 = 38.611) was statistically significant (P < .001), as was the transverse plane main effect (F2,18 = 82.452, P < .001). These findings indicated that there was a statistically significant difference in ischiofemoral space according to hip position in the frontal and transverse planes. The largest ischiofemoral space measurement occurred with the hip in abduction and internal rotation (51.8 mm; 95% confidence interval [CI], 49.2-54.5 mm), whereas hip adduction and external rotation resulted in the narrowest ischiofemoral space measurement (30.8 mm; 95% CI, 25.5-36.0 mm). The largest difference was between the adduction-external rotation and the abduction-internal rotation positions (mean difference = 21.1 mm; 95% CI, 13.7-28.5 mm; P < .001), and the smallest difference was between the adducted-neutral rotation and the abducted-external rotation positions (mean difference = 0.23 mm; 95% CI, -8.07-8.55 mm; P = .99).

CONCLUSIONS

Femoral position affects ischiofemoral space dimensions. The ischiofemoral space widens with abduction and internal rotation and narrows with adduction and external rotation, and thus femoral position should be considered when imaging and measuring the ischiofemoral space.

Sonographically Guided Anterior Cruciate Ligament Injection: Technique and Validation

OBJECTIVE

To describe and validate a practical technique for sonographically guided anterior cruciate ligament (ACL) injections.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Ten unembalmed, cadaveric mid-thigh-knee-ankle foot specimens (5 left knees and 5 right knees; 5 male and 5 female) from 10 donors aged 76 to 93 years (mean 85.6 years) with body mass indices of 17.6 to 42.2 kg/m(2) (mean 28.8 kg/m(2)).

METHODS

A single, experienced operator used a 22-gauge, 63.5-mm stainless steel needle and a 12-3-MHz linear transducer to inject 1.5 mL of diluted colored latex into the ACLs of 10 unembalmed cadaveric specimens via an in-plane, caudad-to-cephalad approach, long axis to the ACL. At a minimum of 24 hours postinjection, specimens were dissected, and the presence and distribution of latex within the ACL assessed by a study co-investigator.

MAIN OUTCOME

Presence and distribution of latex within the ACL.

RESULTS

All 10 injections accurately delivered latex into the proximal (femoral), midsubstance, and distal (tibial) portions of the ACL. No specimens exhibited evidence of needle injury or latex infiltration with respect to the menisci, hyaline cartilage, or posterior cruciate ligament.

CONCLUSIONS

Sonographically guided intra-ligamentous ACL injections are technically feasible and can be performed with a high degree of accuracy. Sonographically guided ACL injections could be considered for research and clinical purposes to directly deliver injectable agents into the healing ACL postinjury or postreconstruction.

Sonographically guided sternoclavicular joint injection: description of technique and validation

OBJECTIVES

The primary purpose of this investigation was to describe and validate a sonographically guided technique for injecting the sternoclavicular joint (SCJ) using a cadaveric model.

METHODS

A single experienced operator (J.S.) completed 13 sonographically guided SCJ injections on 7 unembalmed cadaveric specimens (4 male and 3 female) using an out-of-plane, caudad-to-cephalad technique to place 1 mL of diluted blue latex into the joint. Within 72 hours, study coinvestigators dissected each specimen to determine the injectate location.

RESULTS

All 13 injections accurately placed latex into the SCJ with a predilection for the clavicular side (accuracy, 100%; 95% confidence interval, 73%-100%). Three injections (23%) placed all latex on the clavicular side of the SCJ in the presence of a complete intra-articular disk. Dissection revealed incomplete degenerated disks in the remaining 10 joints. Seven of these injections (54%) clearly placed more than 80% of the latex on the clavicular side, whereas the remaining 3 injections (23%) showed nearly equal latex distribution between the clavicular and sternal sides. No injection resulted in neurovascular injury or extracapsular flow.

CONCLUSIONS

Sonographically guided SCJ injections can be considered in the diagnosis and management of patients presenting with medial shoulder pain syndromes and, using the technique described herein, have a predilection to target the clavicular portion of the joint. In younger patients with possible complete intra-articular disks or in patients with sternal-side conditions, practitioners should consider confirming sternal-side flow after injection or attempt to specifically target the sternal side of the joint.

Sonographically guided distal biceps tendon injections: techniques and validation

OBJECTIVES

The primary purpose of this investigation was to describe and validate sonographically guided techniques for distal biceps peritendinous/intratendinous injections using a cadaveric model.

METHODS

A single experienced operator completed 18 sonographically guided distal biceps peritendinous injections and 15 sonographically guided distal biceps intratendinous injections in 18 unembalmed cadaveric elbow specimens (11 male and 7 female; age, 53-100 years; body mass index, 19.4-42.2 kg/m(2)). Four different peritendinous approaches were used to inject 3 mL of diluted yellow latex: (1) anterior/superficial, (2) posterior/superficial, (3) posterior/deep/short-axis (to the distal biceps tendon), and (4) posterior/deep/long-axis (to the distal biceps tendon). Three different intratendinous approaches were used to inject 1 mL of diluted blue latex: (1) anterior, (2) anterior/pronator window, and (3) posterior. The feasibility of all 7 injections was assessed by the operator in all specimens, and execution difficulty was recorded after each injection. Specimens were subsequently dissected to assess injectate placement.

RESULTS

All 18 peritendinous distal biceps tendon injections accurately placed latex around the tendon without injecting into the tendon proper. All posterior/superficial peritendinous injections delivered injectate to the ulnar side of the tendon. All posterior/deep peritendinous injections delivered injectate to the radial side of the tendon, with the long-axis approach being technically easier than the short-axis approach. Anterior/superficial peritendinous injections delivered injectate predominantly to the anterior side of the tendon and resulted in 1 brachial artery injury. All but 1 of 15 distal biceps intratendinous injections (93%) accurately placed injectate into the tendon proper, with 1 of 5 anterior injections delivering injectate primarily deep to the paratenon. The posterior intratendinous approach was technically the easiest. No intratendinous injection resulted in neurovascular injury.

CONCLUSIONS

Sonographically guided distal biceps peritendinous/intratendinous injections are feasible and therefore may play a role in the management of patients presenting with distal biceps tendinopathy/bursopathy.

Saphenous neuropathy secondary to extraneural ganglion cyst 15 years after reconstruction of the anterior cruciate ligament

This case report describes a 43-year-old woman with a previous anterior cruciate ligament reconstruction and medial meniscectomy who presented with right knee dysesthesias radiating into her medial ankle with associated allodynia. An extensive work-up was pursued, without a definitive diagnosis found or improvement in the patient's symptoms. Eventually, she was referred to Pain Medicine for an ultrasound-guided saphenous nerve (SN) block, where a scan before the injection revealed a large cyst anteromedial to the sartorius in the expected location of the SN. Magnetic resonance imaging and surgical pathology confirmed a juxta-articular ganglion cyst compressing the main SN, just above the take-off of the infrapatellar branch. The cyst was successfully resected, with improvement noted in the patient's neuropathic symptoms postoperatively. Saphenous neuropathy is a rare condition, and to our knowledge this case is the first reported of saphenous neuropathy caused by a knee joint capsule-derived ganglion cyst.

Physical activity, quality of life, and burnout among physician trainees: the effect of a team-based, incentivized exercise program

OBJECTIVE

To prospectively study the effects of an incentivized exercise program on physical activity (PA), quality of life (QOL), and burnout among residents and fellows (RFs) in a large academic medical center.

PARTICIPANTS AND METHODS

In January 2011, all RFs at Mayo Clinic in Rochester, Minnesota (N=1060), were invited to participate in an elective, team-based, 12-week, incentivized exercise program. Both participants and nonparticipants had access to the same institutional exercise facilities. Regardless of participation, all RFs were invited to complete baseline and follow-up (3-month) assessments of PA, QOL, and burnout.

RESULTS

Of the 628 RFs who completed the baseline survey (59%), only 194 (31%) met the US Department of Health and Human Services recommendations for PA. Median reported QOL was 70 on a scale of 1 to 100, and 182 (29%) reported at least weekly burnout symptoms. A total of 245 individuals (23%) enrolled in the exercise program. No significant differences were found between program participants and nonparticipants with regard to baseline demographic characteristics, medical training level, PA, QOL, or burnout. At study completion, program participants were more likely than nonparticipants to meet the Department of Health and Human Services recommendations for exercise (48% vs 23%; P<.001). Quality of life was higher in program participants than in nonparticipants (median, 75 vs 68; P<.001). Burnout was lower in participants than in nonparticipants, although the difference was not statistically significant (24% vs 29%; P=.17).

CONCLUSION

A team-based, incentivized exercise program engaged 23% of RFs at our institution. After the program, participants had higher PA and QOL than nonparticipants who had equal exercise facility access. Residents and fellows may be much more sedentary than previously reported.

Sonographically guided obturator internus injections: techniques and validation

OBJECTIVES

The primary purpose of this investigation was to describe and validate sonographically guided techniques for injecting the obturator internus (OI) muscle or bursa using a cadaveric model.

METHODS

A single experienced operator completed 10 sonographically guided OI injections in 5 unembalmed cadaveric pelvis specimens (4 female and 1 male, ages 71-89 years with body mass indices of 15.5-24.2 kg/m2). Four different techniques were used: (1) OI tendon sheath (4 injections), (2) OI intramuscular (2 injections), (3) OI bursa trans-tendinous (2 injections), and (4) OI bursa short-axis (2 injections). In each case, the operator injected 1.5 mL of diluted yellow latex using direct sonographic guidance and a 22-gauge, 87.5-mm (3½-in) needle. Seventy-two hours later, study coinvestigators dissected each specimen to assess injectate placement.

RESULTS

All 10 OI region injections accurately placed latex into the primary target site. Two of the 4 OI tendon sheath injections produced overflow into the underlying OI bursa. Both OI intramuscular injections delivered 100% of the latex within the OI. All 4 OI bursa injections (2 trans-tendinous and 2 short-axis) delivered 100% of the latex into the OI bursa, with the exception that 1 OI bursa trans-tendinous injection produced minimal overflow into the OI itself. No injection resulted in injury to the sciatic nerve or gluteal arteries, and no injectate overflow occurred outside the confines of the OI or its bursa.

CONCLUSIONS

The results of this investigation demonstrate that sonographically guided injections into the OI or its bursa are feasible and, therefore, may play a role in the diagnosis and management of patients presenting with gluteal and "retrotrochanteric" pain syndromes.

Wire-guided resection of a muscular axillary arch causing neurovascular compression

The axillary arch is a variant muscle found in approximately 7% of individuals. Most reports describe its incidental finding in cadaveric limbs. Several reports describe its potential clinical relevance, typically axillary neurovascular compression due to an axillary arch detected at surgical exploration. This report presents a case in which preoperative identification of this muscle led to a limited surgical approach using computed tomography (CT) guided, percutaneously placed, localizing wires. A 32-year-old man presented with intermittent, vague left arm pain and forearm and hand paresthesias that were aggravated with overhead activity. Routine neurologic examination, electrophysiologic testing, as well as CT and magnetic resonance imaging of the shoulder were interpreted as normal. Focused diagnostic ultrasonography of the axillary region did not reveal a definite abnormality. However, retrospective review of the CT with arms overhead during the ultrasound appointment confirmed the presence of an axillary arch compressing the neurovascular bundle. Percutaneous CT-guided needle localization wires were placed preoperatively to mark the axillary arch, limit the operative exposure, and simplify the resection. Postoperatively, the patient had complete resolution of his arm symptoms and returned to his premorbid activity as a telephone lineman within 6 weeks. At 3-month follow-up, CT with arms overhead confirmed decompression of the neurovascular bundle.