Iliotibial Band Origin Tendinopathy Is an Underrecognized Cause of Anterolateral Hip Pain: A Narrative Review and Clinical Commentary.

ABSTRACT: Hip pain is a common concern among athletes. With gluteal tendinopathy, femoroacetabular impingement, and osteoarthritis predominating sports medicine and musculoskeletal practices, less common etiologies may be overlooked. Complex pelvic anatomy and variable pain referral patterns may make identifying an accurate diagnosis challenging. Employing a systematic approach to evaluation and having a thorough understanding of hip region anatomy are essential. A potentially overlooked cause of anterolateral hip pain is iliotibial band origin tendinopathy. Patients often present with pain around the anterolateral hip and tenderness to palpation at the anterolateral iliac crest. While patients with iliotibial band origin tendinopathy usually respond to nonsurgical intervention, there is little literature to guide evaluation and treatment, highlighting a gap in the recognition of this condition. The purpose of this narrative review is to describe the anatomy of the proximal iliotibial band origin, outline the clinical diagnosis and imaging findings of ITBOT, and summarize current treatment options.

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.

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.

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.

The Role of Ultrasound in the Evaluation of Elbow Medial Ulnar Collateral Ligament Injuries in Throwing Athletes.

PURPOSE OF REVIEW: Although ultrasound (US) imaging is commonly used to evaluate the elbow medial ulnar collateral ligament (mUCL) in throwing athletes, significant technical heterogeneity exists in the published literature and in practice. This has resulted in variable and often ambiguous US diagnostic criteria for mUCL injury. This review summarizes the literature on sonographic evaluation of the mUCL and outlines recommendations for consistent descriptive terminology, as well as future clinical and research applications. RECENT FINDINGS: Both acute and chronic throwing loads in overhead athletes cause the mUCL to become thicker and more lax on stress testing, and these changes tend to revert after a period of prolonged rest. Stress US (SUS) can aid in the diagnosis of mUCL tears and may help identify athletes at risk of mUCL injury. Variability exists in terminology, elbow flexion angle, amount of stress applied, and technique of stress testing. Recent studies have suggested an injured elbow stress delta (SD-change in ulnohumeral joint (UHJ) space with valgus stress) of 2.4 mm and a stress delta difference (SDD-side-side difference in SD) of 1 mm each denote abnormal UHJ laxity due to mUCL injury. US imaging is a powerful and widely accessible tool in the evaluation elbow mUCL injuries. Sonologists should consider how their US techniques compare with published methods and use caution when applying diagnostic criteria outside of those circumstances. Currently, an SD of 2.4 mm and an SDD of 1 mm provide the best diagnostic accuracy for mUCL tears requiring surgery. Finally, preliminary work suggests that shear wave elastography may be helpful in evaluating the biomechanical properties of the mUCL, but additional research is needed.

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.

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.

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.

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.

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 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.

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.

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.

Sonographically Guided Knee Meniscus Injections: Feasibility, Techniques, and Validation.

BACKGROUND: There is a growing interest in the use of biologic agents such as platelet-rich plasma and mesenchymal stem/stromal cells to treat musculoskeletal injuries, including meniscal tears. Although previous research has documented the role of diagnostic ultrasound to evaluate meniscal tears, sonographically guided (SG) techniques to specifically deliver therapeutic agents into the meniscus have not been described. OBJECTIVE: To describe and validate SG injection techniques for the body and posterior horn of the medial and lateral meniscus. DESIGN: Prospective, cadaveric laboratory investigation. SETTING: Academic institution procedural skills laboratory. SUBJECTS: Five unenbalmed cadaveric knee-ankle-foot specimens from 5 donors (3 female and 2 male) ages 33-92 years (mean age 74 years) with body mass indices of 21.1-32.4 kg/m2 (mean 24.1 kg/m2). METHODS: A single, experienced operator completed SG injections into the bodies and posterior horns of the medial and lateral menisci of 5 unenbalmed cadaveric knees using colored latex and a 22-gauge, 38-mm needle. After injection, coinvestigators dissected each specimen to assess latex distribution within the menisci and identify injury to intra-articular and periarticular structures. MAIN OUTCOME MEASURES: Latex location within the target region of meniscus (accurate/inaccurate), and iatrogenic injury to "at risk" intra- and periarticular structures (present/absent). RESULTS: Seventeen of 20 injections were accurate. Two of 3 inaccurate injections infiltrated the posterior horn of the medial meniscus instead of the targeted meniscal body. One inaccurate lateral meniscus injection did not contain latex despite sonographically accurate needle placement. No specimen exhibited injury to regional neurovascular structures or intra-articular hyaline cartilage. CONCLUSIONS: SG meniscus injections are feasible and can accurately and safely deliver injectates such as regenerative agents into bodies and posterior horns of the medial and lateral menisci. The role of SG intrameniscal injections in the treatment of patients with degenerative and traumatic meniscal disorders warrants further exploration. LEVEL OF EVIDENCE: Not applicable.

Ultrasound-Guided Fasciotomy for Chronic Exertional Compartment Syndrome: A Cadaveric Investigation.

BACKGROUND: Chronic exertional compartment syndrome (CECS) is a common cause of exertional leg pain. It is commonly treated with a surgical fasciotomy, which has a surgical complication rate of up to 16% and takes approximately 6-12 weeks to return to preprocedure activity levels. Therefore, the development of a less invasive, effective outpatient intervention to treat CECS is desirable. OBJECTIVE: To describe and validate an ultrasound-guided (USG) fasciotomy technique for the anterior and lateral compartments of the lower limb in an unembalmed cadaveric model. DESIGN: Prospective, cadaveric laboratory investigation. SETTING: Academic institution procedural skills laboratory. SUBJECTS: Ten unembalmed cadaveric knee-ankle-foot specimens from 1 female (2 specimens) and 7 male donors aged 62-91 years (mean 78.6 years) with body mass indices of 18.9-35.3 kg/m2 (mean 27.1 kg/m2). METHODS: Two experienced operators each performed USG anterior and lateral compartment fasciotomies on 5 unembalmed cadaveric legs. A third physician subsequently dissected the legs to assess the continuity of the fasciotomies and to identify any neurovascular damage related to the procedures. MAIN OUTCOME MEASURES: Fasciotomy length (in centimeters) and classification by completeness (achieved target length or did not achieve target length) and continuity (continuous or discontinuous) based on predetermined criteria. Muscles, retinaculae, and neurovascular structures were assessed for damage. RESULTS: No neurovascular injuries occurred in any of the 20 USG fasciotomies. The average fasciotomy length was 22.5 cm. All 20 of the fasciotomies achieved the target length. A continuous cephalocaudal fasciotomy was accomplished in 13 of 20 fasciotomies. When a fasciotomy was not continuous, the average length and number of intact fascial bands was 1.52 cm and 2.3, respectively. CONCLUSIONS: USG fasciotomy of the anterior and lateral leg compartments can be safely performed in a cadaveric model and can achieve a fasciotomy length comparable to surgical fasciotomy. Most procedures successfully achieved a continuous cephalocaudal fasciotomy, although small areas of intact fascial bands were identified in approximately one-third of procedures. The clinical significance of this finding is indeterminate. Given the safety demonstrated with this minimally invasive USG fasciotomy in a cadaveric model, further research is warranted to develop and refine the technique for clinical application. LEVEL OF EVIDENCE: Not applicable.