Accuracy of ultrasound-guided versus fluoroscopically guided contrast-controlled piriformis injections: a cadaveric study

Enhancing Botulinum Toxin Injection Precision: The Efficacy of a Single Cadaveric Ultrasound Training Intervention for Improved Anatomical Localization

Ultrasound guidance can enhance existing landmark-based injection methods, even through a brief and single exposure during a cadaveric training course. A total of twelve participants were enrolled in this training program, comprising nine physical medicine and rehabilitation specialists, one pediatrician, and two physician assistants. For each participant, one upper-limb muscle and one lower-limb muscle were randomly chosen from the preselected muscle group. Subsequently, participants were tasked with injecting both of their chosen cadaveric muscles with 1 mL of acrylic paint using a manual needle palpation technique, relying solely on their knowledge of anatomic landmarks. Participants then underwent a personalized, one-to-one ultrasound teaching session, lasting approximately five minutes, conducted by two highly experienced instructors. Following this instructive phase, participants were tasked with a second round of injections, targeting the same two muscles in the lower and upper limbs. However, this time, the injections were performed using anatomical landmarks and ultrasound guidance. To facilitate differentiation from the initial injections, a distinct color of acrylic paint was employed. When employing the anatomical landmark-based approach, the overall success rate for injections was 67%, with 16 out of 24 targeted muscles accurately injected. With the incorporation of ultrasound guidance, the success rate was 92%, precisely targeting 22 out of the 24 muscles under examination. There was an improvement in injection accuracy achievable through the integration of ultrasound guidance, even with minimal training exposure. Our single cadaveric ultra-sound training program contributes valuable insights to the utilization of ultrasound for anatomy training to help optimize the targeting of BoNT-A.

Myofascial pain - A major player in musculoskeletal pain

Myofascial pain is a soft tissue pain syndrome with local and referred musculoskeletal pain arising from trigger points. Myofascial pain and myofascial pain syndromes are among some of the most common acute and chronic pain conditions. Myofascial pain can exist independently of other pain generators or can coexist with or is secondary to other acute and chronic painful musculoskeletal conditions. Myofascial pain is most effectively treated with a multimodal treatment plan including injection therapy (known as trigger point injections, physical therapy, postural or ergonomic correction, and treatment of underlying musculoskeletal pain generators. The objectives of this review are to outline the prevalence of myofascial pain, describe the known pathophysiology of myofascial pain and trigger points, discuss the clinical presentation of myofascial pain, and present evidence-based best practices for pharmacologic, non-pharmacologic, and interventional treatments for myofascial pain.

Piriformis syndrome

Piriformis syndrome is a condition that is proposed to result from compression of the sciatic nerve, either in whole or in part, in the deep gluteal space by the piriformis muscle. The prevalence of piriformis syndrome depends upon the diagnostic criteria being used and the population studied but is estimated by some to be 5%-6% in all cases of low back, buttock, and leg pain and up to 17% of patients with chronic low back pain. While the sciatic nerve may pierce the piriformis muscle in about 16% of healthy individuals, this frequency is no different in those with the syndrome; thus, the relationship to this anatomic finding is unclear. The most common symptoms are buttock pain, external tenderness over the greater sciatic notch, and aggravation of the pain through sitting. Many clinical signs are reported for piriformis syndrome, but the sensitivity and specificity are unclear, in part because of the lack of a uniformly accepted case definition. In the majority of cases in the literature, it appears that the diagnosis is more ascribed to a myofascial condition rather than a focal neuropathy. Electrodiagnostic studies can be useful to exclude other causes of symptoms, but there is no well-accepted test to confirm the presence of piriformis syndrome. Ultrasound imaging may show thickening of the piriformis muscle, but further research is required to confirm that this is correlated with the clinical diagnosis. Magnetic resonance imaging and neurography may hold promise in the future, but there are not yet sufficient data to support adopting these methods as a standard diagnostic tool. The initial treatment of piriformis syndrome is typically conservative management with the general rehabilitation principles similar to other soft tissue musculoskeletal conditions. Local anesthetic, botulinum toxin, and/or corticosteroid injections have been reported by some to be beneficial for diagnostic or treatment purposes. Surgical interventions have also been used with variable success.

Botulinum toxin injection strategy of intractable and relapsed piriformis syndrome: A case report

RATIONALE

Piriformis syndrome (PS) is neuromuscular disorder caused by sciatic nerve compression by piriformis muscle and related to sciatic-type pain. When the conservative care fails, local injection or surgery can be also performed into piriformis. In recent years, botulinum toxin (BoNT) has also been considered as a new therapeutic option of piriformis syndrome.

PATIENT CONCERNS

A man in his late 40s came to pain clinic for left low back pain. The symptom was aggravated with sitting position.

DIAGNOSIS

Piriformis syndrome.

INTERVENTIONS

The patient underwent BoNT injection with 100 IU with 2 mL into piriformis muscle for piriformis syndrome treatment, and his pain was relieved. However, it recurred 8 months later. BoNT injection was repeated with 100 IU with 5 mL.

OUTCOMES

At the time of this writing, his pain was reduced for 2 years without any medication.

LESSONS

We report a case of treating relapsed piriformis syndrome with BoNT injection of different dilution volume, suggesting that the higher the dilution volume, the more effective for therapeutic effect of BoNT.

Visualizing Anatomic Variants of the Sciatic Nerve Using Diagnostic Ultrasound During Piriformis Muscle Injection: An Example of 4 Cases

Objective

The aim of this article is to present examples of patients in whom piriformis muscle (PM) and sciatic nerve (SN) variations were detected by a diagnostic ultrasound (US)-guided examination and were successfully diagnosed and treated for piriformis syndrome (PS) by US-guided injections.

Clinical Features

This series includes 4 cases. In case 1, a 30-year-old woman with a 7 numeric rating scale (NRS) score for pain (on a 0-10 scale) was evaluated for complaints of left gluteal pain radiating to the thigh for 5 years and right gluteal pain for 2 years. Case 2 involves a 32-year-old man with a 7 NRS score presenting with left gluteal pain radiating to his leg for 1 year. The third case presents a 37-year-old man who had pain (6 NRS score), numbness, and discomfort radiating from the right hip to the leg that lasted for 7 years. Finally, in case 4, a 23-year-old male patient was examined with deep gluteal paresthesia and discomfort on the left side for 1 year.

Intervention and Outcome

Diagnostic US evaluation of the gluteal region for each patient revealed anatomical variations of the SN. In 3 of the cases, corresponding contralateral US images demonstrated similar anatomic variations. Diagnosis of PS in each patient was made by US-guided injection. After the injection of 4 cm³ of lidocaine 2% into the PM, the patients' complaints resolved almost fully.

Conclusion

The anatomical variations of the SN and PM might be a facilitating factor for myofascial pain syndrome in PS. These cases demonstrate that SN variations could be visualized with the help of diagnostic US.

Trigger Point Injections

Myofascial pain and myofascial pain syndromes are among some of the most common acute and chronic pain conditions. Many interventional procedures can be performed in both an acute and chronic pain setting to address myofascial pain syndromes. Trigger point injections can be performed with or without imaging guidance such as fluoroscopy and ultrasound; however, the use of imaging in years past has been recommended to improve patient outcome and safety. Injections can be performed using no injectate (dry needling), or can involve the administration of local anesthetics, botulinum toxin, or corticosteroids.

Effect of hip external rotator muscle contraction on pelvic floor muscle function and the piriformis

INTRODUCTION AND HYPOTHESIS

There is a lack of in-depth understanding of the muscles surrounding the pelvic floor muscle (PFM). The study aimed to investigate the functional relationship between PFM and hip external rotator muscles by observing the piriformis muscle thickness and displacement of the bladder base under different contraction conditions of the hip external rotator and/or PFM. We hypothesized that PFM function would be the strongest when the hip external rotator and PFM contracted simultaneously and that during PFM contraction, the piriformis muscle would act as an auxiliary muscle and show coactivation.

METHODS

The participants included 13 healthy adult women (mean age 23.8 ± 2.8 years). The three contraction conditions were PFM contraction, hip external rotator contraction, and simultaneous contraction of the hip external rotator and PFM. During the tasks, the piriformis muscle thickness and bladder base displacement were measured using ultrasonography and compared among the contraction conditions using one-way analysis of variance.

RESULTS

Significant differences were noted in bladder base displacement among the three contraction conditions (P < 0.01), with PFM contraction having the highest value. The piriformis muscle thickness showed the greatest increase in simultaneous contraction.

CONCLUSIONS

In our study, we showed PFM contraction positively influences piriformis contraction, while PFM function operationalized by bladder base displacement was highest during PFM contraction alone.

Ultrasound-guided trigger point injection for piriformis syndrome in the emergency department

Piriformis syndrome, a myofascial pain disorder characterized by deep gluteal pain that radiates to the ipsilateral lower back and/or posterior thigh, is an underreported cause of low back pain frequently misdiagnosed in the emergency department (ED). Often refractory to oral pain medications, this syndrome can be debilitating. Ultrasound-guided trigger point injection of the piriformis muscle can treat piriformis syndrome, but no previous reports exist in the emergency medicine literature. This case series describes 2 patients who presented to our emergency department with low back pain and were diagnosed with piriformis syndrome. Both patients received an ultrasound-guided trigger point injection of the affected piriformis muscle with a significant reduction of pain at 15 minutes and 48 hours after the procedure.

Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis. After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy. Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve. Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment. Cite this article: Bone Joint J 2020;102-B(5):556-567.

Targeted Ultrasound-Guided Perineural Hydrodissection of the Sciatic Nerve for the Treatment of Piriformis Syndrome

Piriformis syndrome is a common cause of lumbar, gluteal, and thigh pain, frequently associated with sciatic nerve symptoms. Potential etiologies include muscle injury or chronic muscle stretching associated with gait disturbances. There is a common pathological end pathway involving hypertrophy, spasm, contracture, inflammation, and scarring of the piriformis muscle, leading to impingement of the sciatic nerve. Ultrasound-guided piriformis injections are frequently used in the treatment of these pain syndromes, with most of the published literature describing injection of the muscle. We describe a safe, effective ultrasound-guided injection technique for the treatment of piriformis syndrome using targeted sciatic perineural hydrodissection followed by therapeutic corticosteroid injection.

Treatment strategies for ischiofemoral impingement: a systematic review

PURPOSE

There has been relatively little information about the treatment for ischiofemoral impingement (IFI) because of its rarity as well as the uncertainty of diagnosis. The aim of this study was to provide the reader with the available treatment strategies and their related outcomes for IFI based on the best available evidence, whilst highlighting classically accepted ways of treatment as well as relatively new surgical and non-surgical techniques.

METHODS

A systematic review of the literature from Medline, Embase, AMED, Cochrane and Google Scholar was undertaken since inception to December 2017 following the PRISMA guidelines. Clinical outcome studies, prospective/retrospective case series and case reports that described the treatment outcome for IFI were included. Animal or cadaveric studies, trial protocols, diagnostic studies without any description of treatments, technical notes without any results, and review articles were excluded.

RESULTS

This systematic review found 17 relevant papers. No comparative studies were included in the final records for qualitative assessment, which means all the studies were case series and case reports. Eight studies (47.1%) utilised non-surgical treatment including injection and prolotherapy, followed by endoscopic surgery (5 studies, 29.4%) then open surgery (4 studies, 23.5%). Mean age of the participants was 41 years (11-72 years). The mean follow-up was 8.4 months distributed from 2 weeks to 2.3 years. No complications or adverse effects were found from the systematic review.

CONCLUSION

Several treatment strategies have been reported for IFI, and most of them have good short- to medium-term outcomes with a low rate of complications. However, there are no comparative studies to assess the superiority of one technique over another, thus further research with randomised controlled trials is required in this arena. This study explores the wide variety and categories of different treatments used for IFI to guide physicians and shed light on what can be done for this challenging cohort of patients.

LEVEL OF EVIDENCE

III.

Piriformis Syndrome: A Narrative Review of the Anatomy, Diagnosis, and Treatment

Piriformis syndrome is a form of sciatica caused by compression of the sciatic nerve by the piriformis muscle. It is a relatively uncommon, but not insignificant, cause of sciatica. The diagnosis of piriformis syndrome is complicated by the large differential diagnosis of low back and buttock pain with many diagnoses having overlapping symptoms. This narrative review highlights the relevant anatomy, history, physical exam maneuvers, electrodiagnostic findings, and imaging findings that are used to diagnose piriformis syndrome. Also discussed are posterior gluteal myofascial pain syndromes that mimic piriformis syndrome. The review then outlines the different treatment options for piriformis syndrome including conservative treatment, injections, and surgical treatment. In addition, it provides the reader with a clinical framework to better understand and treat the complex, and often misunderstood, diagnosis of piriformis syndrome.

Ultrasound-Guided Hip Injections

The diagnosis of hip pain can be difficult to isolate because the discomfort can originate from several locations and compensatory pain patterns. Pain generators can include the intra- and extra-articular hip structures, the lumbar spine, the pelvic floor, or a combination of these. It can also be referred as pain from the bowel, bladder, or reproductive organs. Injections into and around the hip have become an important part of both diagnostic and nonsurgical treatment algorithm for hip pain. The proximity of the hip to important neurovascular structures, lack of palpable anatomic landmarks, and deep location of targets can make use of ultrasonography-guided injections ideal. These injections have been growing in popularity in the orthopedic community because ultrasonography allows for a real-time visualization of dynamic anatomy without any radiation exposure to the patient and physician. The use of ultrasonography has allowed for in-office image guidance with improved accuracy for more targeted and advanced procedures. The patient's response to these injections can help guide patient selection for surgery and allow for better pain control of the soft-tissue pathology that often accompanies intra-articular pathology. This article highlights the diagnostic and therapeutic value of ultrasonography-guided hip injections for an orthopedic practice. The focus is on sonographic anatomy, introduction to technique, common indications, and pearls and pitfalls of these procedures.

Ultrasound Intervention of the Lower Extremity/Pelvis

Musculoskeletal (MSK) conditions are growing in prevalence. Ultrasound (US) is increasingly used for managing MSK conditions due to its low cost and ability to provide real-time image guidance during therapeutic interventions. As MSK US becomes more widespread, familiarity and comfort with US-guided interventions will become increasingly important. This article focuses on general concepts regarding therapeutic US-guided injections of corticosteroids and platelet-rich plasma and highlights several of the US-guided procedures commonly performed, involving the pelvis and lower extremity.

Saphenous Nerve Block From Within the Knee Is Feasible for TKA: MRI and Cadaveric Study

BACKGROUND

Surgeon-performed periarticular injections and anesthesiologist-performed femoral nerve or adductor canal blocks with local anesthetic are in common use as part of multimodal pain management regimens for patients undergoing TKA. However, femoral nerve blocks risk causing quadriceps weakness and falls, and anesthesiologist-performed adductor canal blocks are costly in time and resources and may be unreliable. We investigated the feasibility of a surgeon-performed saphenous nerve ("adductor canal") block from within the knee at the time of TKA.

QUESTIONS/PURPOSES

(1) Can the saphenous nerve consistently be identified distally on MRI studies, and is there a consistent relationship between the width of the femoral transepicondylar axis (TEA) and the proximal (cephalad) location where the saphenous nerve emerges from the adductor canal? With these MRI data, we asked the second question: (2) Can we utilize this anatomic relationship to simulate a surgeon-performed intraoperative block of the distal saphenous nerve from within the knee with injections of dyes after implantation of trial TKA components in cadaveric lower extremity specimens?

METHODS

A retrospective analysis of 94 thigh-knee MRI studies was performed to determine the relationship between the width of the distal femur at the epicondylar axis and the proximal location of the saphenous nerve after its exit from the adductor canal and separation from the superficial femoral artery. These studies, obtained from one hospital's MRI library, had to depict the saphenous nerve in the distal thigh and the femoral epicondyles and excluded patients younger than 18 years of age or with metal implants. These studies were performed to evaluate thigh and knee trauma or unexplained pain, and 55 had some degree of osteoarthritis. After obtaining these data, TKA resections and trial component implantation were performed, using a medial parapatellar approach, in 11 fresh cadaveric lower extremity specimens. There were six male and five female limbs from cadavers with a mean age of 70 years (range, 57-80 years) and mean body mass index of 20 kg/m (range, 15-26 kg/m) without known knee arthritis. Using a blunt-tipped 1.5-cm needle, we injected 10 mL each of two different colored solutions from inside the knee at two different locations and, after 30 minutes, dissected the femoral and saphenous nerves and femoral artery from the hip to the knee. Our endpoints were whether the saphenous nerve was bathed in dye and if the dye or needle was located in the femoral artery or vein.

RESULTS

Based on the MRI analysis, the mean ± SD TEA was 75 ± 4 mm in females and 87 ± 4 mm in males. The saphenous nerve exited the adductor canal and was located at a mean of 1.5 ± 0.16 times the TEA width in females and a mean of 1.3 ± 0.13 times the TEA width in males proximal to the medial epicondyle. After placement of TKA trial components and injection, the proximal injection site solution bathed the saphenous nerve in eight of 11 specimens. In two cachectic female cadaver limbs, the dye was located posteriorly to the nerve in hamstring muscle. The proximal blunt needle and colored solution were directly adjacent to but did not penetrate the femoral artery in only one specimen.

CONCLUSIONS

This study indicates, based on MRI measurements, cadaveric injections, and dissections, that a surgeon-performed injection of the saphenous nerve from within the knee after it exits from the adductor canal seems to be a feasible procedure.

CLINICAL RELEVANCE

This technique may be a useful alternative to an ultrasound-guided block. A trial comparing surgeon- and anesthesiologist-performed nerve block should be considered to determine the clinical efficacy of this procedure.

Bone marrow aspiration for regenerative orthopedic intervention: technique with ultrasound guidance for needle placement

Aim: We review relevant anatomy of the iliac crest, and describe an interventional technique to maximize harvesting of desired progenitor cells with ultrasound to guide safe trochar placement. Materials & methods: We validated the technique on both sides of the pelvis in four human cadavers. Results: Using ultrasound guidance, 32 BMA needles were placed in a safe zone along various portions of the iliac crest. Conclusion: Ultrasound guidance can improve accuracy of bone marrow aspirations form the iliac crest. Mastery of this procedure will facilitate cell harvest and aid in patient safety when procuring mesenchymal stem cells from a bone marrow source.

The effects of three types of piriform muscle stretching on muscle thickness and the medial rotation angle of the coxal articulation

[Purpose] The purpose of this study was three kinds of stretching methods and measured the change in the thickness of the piriform muscle in real time using ultrasound images and compared the medial rotation angle of the coxal articulation. [Subjects and Methods] Fourty-five subjects who attend B University in Cheonan, divided into three groups. The subjects in these three groups then underwent stretching with flexion of coxal articulation over 90°, stretching with flexion of coxal articulation under 90°, and muscle energy technique (MET) application. The main outcome measures were piriform muscle thickness and medial rotation angle of the coxal articulation. [Results] All groups showed decreased piriform muscle thickness and increased medial rotation angle of the coxal articulation. [Conclusion] Based on the above results, three kinds of piriform muscle stretching methods are effective of reduce muscle thickness and increase medial rotation angle of the coxal articulation.

Musculoskeletal Approach to Pelvic Pain

Visceral and somatic causes of pelvic pain are often inter-related, and a musculoskeletal examination should always be considered for the successful diagnosis and treatment of pelvic pain. For the diverse etiologies of hip pain, there are many unique considerations for the diagnosis and treatment of these various disorders. Pelvic pain is often multidimensional due to the overlap between lumbo-hip-pelvic diagnoses and may require a multidisciplinary approach to evaluation and management.

Diffusion tensor imaging and tractography of the sciatic nerve: assessment of fractional anisotropy and apparent diffusion coefficient values relative to the piriformis muscle, a preliminary study

OBJECTIVE

Piriformis muscle syndrome (PMS) is underdiagnosed. To evaluate the potential of diffusion tensor imaging and diffusion tensor tractography as innovative tools for the diagnosis of PMS by functional assessment of the sciatic nerve, the aims of this study are to assess the reproducibility and to evaluate the changes in the parameters at levels proximal and distal to the piriformis.

MATERIALS AND METHODS

Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve at three levels were quantified twice each by two examiners using the fiber-tracking method. In the first part of the study, laterality and reproducibility were evaluated using intraclass correlation coefficients (ICC) in ten healthy volunteers. In the second part of the study, the healthy side and symptomatic side were assessed in ten consecutive patients with sciatica. There were three patients with no findings on lumbar magnetic resonance imaging (MRI).

RESULTS

There was no laterality in either FA or ADC values in asymptomatic patients at any level. The mean intra-rater ICC was 0.90 and the mean inter-rater ICC was 0.87. FA was significantly lower and ADC significantly higher on the symptomatic side at each level in patients with sciatica. In the three sciatica patients with no findings on lumbar MRI, FA was significantly lower and ADC was significantly higher only at levels distal to the piriformis. These patients experienced full pain relief after ultrasound-guided injection of local anesthesia.

CONCLUSIONS

Diffusion tensor imaging and diffusion tensor tractography might be innovative tools for the diagnosis of PMS.

Musculoskeletal interventional procedures: With or without imaging guidance?

Aspiration and injection of joints and soft tissues is an indispensable skill used in everyday practice by the clinical rheumatologist. Most rheumatologists recognise that performing these procedures using anatomical landmarks is not always successful, particularly in the case of small or infrequently injected joints, bursae or tendon sheaths. Musculoskeletal ultrasound confirms the local pathological-anatomical diagnosis and is the most applicable and feasible imaging method that can be applied in clinical practice in guiding musculoskeletal interventional procedures. From 1993, there has been substantial examination of the accuracy of landmark- and imaging-guided procedures. We have searched the literature and ascertained whether imaging techniques improve the accuracy of musculoskeletal procedures and whether the accuracy of needle placement can be translated into improved clinical outcome (efficacy).

Ultrasound-Guided Hip Procedures

This article describes the techniques for performing ultrasound-guided procedures in the hip region, including intra-articular hip injection, iliopsoas bursa injection, greater trochanter bursa injection, ischial bursa injection, and piriformis muscle injection. The common indications, pitfalls, accuracy, and efficacy of these procedures are also addressed.

Ultrasound-guided piriformis muscle injection. A new approach

Piriformis syndrome is an uncommon cause of buttock and leg pain. Some treatment options include the injection of piriformis muscle with local anesthetic and steroids. Various techniques for piriformis muscle injection have been described. Ultrasound allows direct visualization and real time injection of the piriformis muscle. We describe 5 consecutive patients, diagnosed of piriformis syndrome with no improvement after pharmacological treatment. Piriformis muscle injection with local anesthetics and steroids was performed using an ultrasound technique based on a standard technique. All 5 patients have improved their pain measured by numeric verbal scale. One patient had a sciatic after injection that improved in 10 days spontaneously. We describe an ultrasound-guided piriformis muscle injection that has the advantages of being effective, simple, and safe.

Resident Accuracy of Electromyography Needle Electrode Placement Using Ultrasound Verification

BACKGROUND

Electromyography (EMG) and musculoskeletal (MSK) ultrasound (US) are core learning objectives during physical medicine and rehabilitation (PM&R) training. However, there have been no prior studies using MSK US to assess the acquisition of EMG procedural skills during residency training. This study aims to demonstrate the differences in skillful needle placement between junior and senior physiatry residents. The integration of both EMG and MSK US may have tremendous potential for additional learning opportunities related to electrodiagnostic education.

OBJECTIVE

To determine the accuracy of anatomic landmark-guided EMG needle electrode placement in commonly used muscles by PM&R resident physicians.

DESIGN

Cross-sectional study.

SETTING

An academic PM&R residency program.

PARTICIPANTS

Twelve (5 postgraduate year [PGY] -3 and 7 PGY-4) PM&R resident physicians participating in a MSK US training course.

METHODS

Twelve PM&R residents in the eighth month of their third and fourth years of postgraduate training performed anatomic landmark-guided needle placement to the extensor indicis proprius (EIP), pronator teres (PT), peroneus longus (PL), and soleus muscles of live subjects. Once the needle electrode was satisfactorily placed, needle localization was verified with US.

MAIN OUTCOME MEASURES

Accuracy of EMG needle electrode placement.

RESULTS

The overall accuracy of needle electrode placement for all resident participants was 68.8%. The mean accuracy of the 4 selected muscles was 50% by PGY-3 residents and 82.1% for PGY-4 residents (P = .01). EIP was the most commonly missed muscle, with correct placement performed by 20% of PGY-3 and 42.9% of PGY-4 residents. PGY-3 residents demonstrated 60% accuracy with localizing the PT, PL, and soleus muscles. PGY-4 residents demonstrated 85.7% accuracy for PT, and 100% accuracy for both PL and soleus muscles.

CONCLUSIONS

Senior residents demonstrated greater accuracy of landmark-guided needle placement than junior residents. EMG procedural skills are important milestones in PM&R training, and MSK US may be a useful tool to enhance resident learning.

American Medical Society for Sports Medicine (AMSSM) position statement: interventional musculoskeletal ultrasound in sports medicine

The use of diagnostic and interventional ultrasound has significantly increased over the past decade. A majority of the increased utilization is by nonradiologists. In sports medicine, ultrasound is often used to guide interventions such as aspirations, diagnostic or therapeutic injections, tenotomies, releases, and hydrodissections. This American Medical Society for Sports Medicine (AMSSM) position statement critically reviews the literature and evaluates the accuracy, efficacy, and cost-effectiveness of ultrasound-guided injections in major, intermediate, and small joints, and soft tissues, all of which are commonly performed in sports medicine. New ultrasound-guided procedures and future trends are also briefly discussed. Based upon the evidence, the official AMSSM position relevant to each subject is made.

Usefulness of Magnetic Resonance Neurography for Diagnosis of Piriformis Muscle Syndrome and Verification of the Effect After Botulinum Toxin Type A Injection: Two Cases

Piriformis muscle syndrome (PMS) is a controversial neuromuscular disorder that is presumed to involve compression neuropathy of the sciatic nerve at the level of the piriformis muscle. Botulinum toxin A (BTX-A) injection into the piriformis muscle is widely used as a treatment aimed at relieving sciatic nerve compression. In 2 patients with PMS, magnetic resonance neurography (MRN) was taken before and after BTX-A injection. The first MRN was performed as a diagnostic tool, and the second to identify the effect of the treatment. Signal change of the sciatic nerve under the hypertrophied piriformis muscle was confirmed by MRN. In follow-up MRN performed after BTX-A injection into the piriformis muscle, changes of the sciatic nerve and piriformis muscle were noticed as well as improvement of clinical symptoms. MRN is a useful tool to add certainty of diagnosis and verify the effect of treatment in PMS.

A Survey of Ultrasound Training in U.S. and Canadian Chronic Pain Fellowship Programs

OBJECTIVE

To assess the current state of ultrasound training in U.S. and Canadian Chronic Pain Fellowship programs.

DESIGN

U.S. as well as Canadian chronic pain fellowship programs were contacted via email and program directors were asked to complete a survey. The surveys were completed online using a questionnaire.

SETTING

Questionnaire via email.

PATIENTS

None.

INTERVENTIONS

None.

OUTCOME

To assess the current state of ultrasound training in U.S. and Canadian Chronic Pain Fellowship programs.

MEASURES

Current teaching structure, types, and numbers of ultrasound-guided interventional pain procedures.

RESULTS

Thirty-one responses (30.7%) from the 97 U.S. and four Canadian programs surveyed. Of the 31 programs that responded, 26 offered ultrasound training; five did not. These 31 programs averaged 4.1 fellows per year, majority 96.2% of the 26 programs taught ultrasound throughout the fellowship year. The type of ultrasound training varied, with the large majority 96.2% being patient based. Among 26 programs, 96.2% used ultrasound for peripheral nerve blocks, 76.9% used ultrasound for non-axial musculoskeletal injections, and 53.8% used ultrasound for axial nerve blocks.

CONCLUSIONS

Chronic pain fellowships were teaching ultrasound-guided procedures to their fellows. The majority of the fellowships offered ultrasound training throughout the fellowship year. A majority of training was accomplished via hands-on experience with patients. Chronic pain fellows were receiving a majority of ultrasound training for peripheral nerve blocks, followed by nonaxial musculoskeletal blocks, with few axial nerve blocks being taught.

American Medical Society for Sports Medicine position statement: interventional musculoskeletal ultrasound in sports medicine

The use of diagnostic and interventional ultrasound has significantly increased over the past decade. A majority of the increased utilization is by nonradiologists. In sports medicine, ultrasound is often used to guide interventions such as aspirations, diagnostic or therapeutic injections, tenotomies, releases, and hydrodissections. This American Medical Society for Sports Medicine (AMSSM) position statement critically reviews the literature and evaluates the accuracy, efficacy, and cost-effectiveness of ultrasound-guided injections in major, intermediate, and small joints, and soft tissues, all of which are commonly performed in sports medicine. New ultrasound-guided procedures and future trends are also briefly discussed. Based on the evidence, the official AMSSM position relevant to each subject is made.

American Medical Society for Sports Medicine (AMSSM) position statement: interventional musculoskeletal ultrasound in sports medicine

BACKGROUND

The use of diagnostic and interventional ultrasound has significantly increased over the past decade. A majority of the increased utilisation is by non-radiologists. In sports medicine, ultrasound is often used to guide interventions such as aspirations, diagnostic or therapeutic injections, tenotomies, releases and hydrodissections.

OBJECTIVE

Critically review the literature related to the accuracy, efficacy and cost-effectiveness of ultrasound-guided injections (USGIs) in major, intermediate and small joints; and soft tissues.

DESIGN

Systematic review of the literature.

RESULTS

USGIs are more accurate than landmark-guided injections (LMGIs; strength of recommendation taxonomy (SORT) Evidence Rating=A). USGIs are more efficacious than LMGIs (SORT Evidence Rating=B). USGIs are more cost-effective than LMGIs (SORT Evidence Rating=B). Ultrasound guidance is required to perform many new procedures (SORT Evidence Rating=C).

CONCLUSIONS

The findings of this position statement indicate there is strong evidence that USGIs are more accurate than LMGI, moderate evidence that they are more efficacious and preliminary evidence that they are more cost-effective. Furthermore, ultrasound-guided (USG) is required to perform many new, advanced procedures and will likely enable the development of innovative USG surgical techniques in the future.

Comparison of anatomic landmarks and ultrasound guidance for intercostal nerve injections in cadavers

BACKGROUND AND OBJECTIVES

Intercostal nerve (ICN) injections are routinely performed under anatomic landmark or fluoroscopic guidance for acute and chronic pain indications. Ultrasound (US) is being used increasingly to perform ICN injections, but there is lack of evidence to support categorically the benefits of US over conventional techniques. We compared guidance with US versus anatomic landmarks for accuracy and safety of ICN injections in cadavers in a 2-phase study that included evaluation of deposition of injected dye by dissection and spread of contrast on fluoroscopy.

METHODS

A cadaver experiment was performed to validate US as an imaging modality for ICN blocks. In the first phase of the study, 12 ICN injections with 2 different volumes of dye were performed in 1 cadaver using anatomic landmarks on one side and US-guidance on the other (6 injections on each side). The cadaver was then dissected to evaluate spread of the dye. The second phase of the study consisted of 74 ICN injections (37 US-guided and 37 using anatomic landmarks) of contrast dye in 6 non-embalmed cadavers followed by fluoroscopy to evaluate spread of the contrast dye.

RESULTS

In the first phase of the study, the intercostal space was identified with US at all levels. Injection of 2 mL of dye was sufficient to ensure compete staining of the ICN for 5 of 6 US-guided injections but anatomic landmark guidance resulted in correct injection at only 2 of 6 intercostal spaces. No intravascular injection was found on dissection with either of the guidance techniques. In the second phase of the study, US-guidance was associated with a higher rate of intercostal spread of 1 mL of contrast dye on fluoroscopy compared with anatomic landmarks guidance (97% vs 70%; P = 0.017).

CONCLUSIONS

Ultrasound confers higher accuracy and allows use of lower volumes of injectate compared with anatomic landmarks as a guidance method for ICN injections in cadavers. Ultrasound may be a viable alternative to anatomic landmarks as a guidance method for ICN injections.

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.

Sonographically guided distal radioulnar joint injection: technique and validation in a cadaveric model

Distal radioulnar joint (DRUJ) disorders are uncommon but important causes of ulnar-sided wrist pain and disability. Fluoroscopically guided injections may be performed to diagnose or treat DRUJ-related pain or as part of a diagnostic arthrogram. Sonographic guidance may provide a favorable alternative to fluoroscopic guidance for distal DRUJ injections. This report describes and validates a sonographically guided technique for DRUJ injections in an unembalmed cadaveric model. An experienced clinician used sonographic guidance to inject diluted colored latex into the DRUJs of 10 unembalmed cadaveric specimens. Subsequent dissection by a fellowship-trained hand surgeon confirmed accurate injections in all 10 specimens. Two cases of ulnocarpal flow, indicative of triangular fibrocartilage injury, were noted during injection and subsequently confirmed during dissection. Clinicians should consider using sonographic guidance to perform DRUJ injections when clinically indicated. Further research should explore the efficacy of sonographically guided DRUJ injections to treat patients with painful DRUJ syndromes or to evaluate the triangular fibrocartilage complex in patients with ulnar wrist pain syndromes.

Optimization of ingredients, procedures and rehabilitation for platelet-rich plasma injections for chronic tendinopathy

SUMMARY There is considerable interest amongst clinicians and researchers to create the optimal platelet product to maximize outcomes with platelet-rich plasma (PRP) injections. PRP has been widely introduced as a safe alternative for treating tendinopathies. However, there is still limited clinical evidence describing the components of the platelet product and supporting its use in clinical trials. This article reviews the current literature regarding the role of PRP injections in the treatment of recalcitrant tendinopathies and the different factors in the platelet product that could affect the outcome, including the platelet count, presence of leukocytes, activators used, pH of solution and delivery method, among others. In addition, we address important concepts regarding rehabilitation after PRP procedures, which has little consensus to date and is the subject of much debate. Based on the phases of soft tissue healing, basic science research on platelets, as well as our clinical experience in treating over 500 patients with PRP, we will suggest guidelines regarding the optimal progression of rehabilitation and timing for return to previous activity following the procedure.