Accuracy of Ultrasound-Guided Intra-articular Hip Injections Performed in the Orthopedic Clinic

Case Report: Portable handheld ultrasound facilitates intra-articular injections in articular foot pathologies

Background

Intra-articular injections are commonly used to manage joint pathologies, including osteoarthritis. While conventional ultrasound (US) guidance has generally improved intra-articular injection accuracy, forefoot and midfoot joint interventions are still often performed without imaging guidance. This pilot study aims to evaluate the efficacy of office-based, portable ultrasound (P-US) guided intra-articular injections for forefoot and midfoot joint pain caused by various degenerative pathologies.

Methods

A retrospective analysis was conducted on a series of consecutive patients who underwent P-US guided intra-articular injections following a chief complaint of forefoot or midfoot joint pain. Patients reported their pain levels using the Visual Analog Scale (VAS) pre-injection and at 3 months follow-up. The procedure was performed by an experienced foot and ankle surgeon using a linear array transducer for guidance, and a 25-gauge needle was used to inject a combination of 2 cc 1% lidocaine and 12 cc of Kenalog (40 mg/ml). Complications and pain scores were analyzed using a paired t-test and p < 0.05 was considered significant.

Results

We included 16 patients, 31% male and 69% female with a mean age (±SD) of 61.31 (±12.04) years. None of the patients experienced immediate complications following the intervention. The mean pre-injection VAS score was significantly reduced from 5.21 (±2.04) to a mean of 0.50 (±1.32) at 3 months follow-up (P < 0.001). Thirteen patients reported complete resolution of pain at the 3-month follow-up. No adverse events were reported throughout the duration of the study.

Conclusion

This pilot study suggests P-US-guided intra-articular injections offer a safe and effective method for managing forefoot and midfoot joint pain caused by various arthritic pathologies. Further research is warranted to establish the long-term efficacy and comparative effectiveness of P-US-guided injections in larger patient cohorts as compared to non-image guided injections.

Posterior intra-articular hip injections: a pilot study investigating a new approach

PURPOSE

The purpose of this study was to investigate a novel posterior intra-articular hip injection approach while discussing the clinical pearls for methodology, accuracy, and associated adverse events. The goal was to investigate if this approach could potentially be used in those where the typical anterior access would be challenging.

MATERIALS AND METHODS

10 adults (age > 18 years) who were referred to a tertiary outpatient clinic for hip injection due to hip osteoarthritis or femoral acetabular impingement with labral tearing to a single academic sports medicine clinic. Patients were placed in prone position. Posterior structures were identified using a curvilinear transducer. A 22 gauge 3.5-6-inch spinal needle was advanced in-plane to the transducer towards the hip capsule at the head-neck junction of the femur from inferolateral to superomedial. A fluoroscopic arthrogram was obtained to evaluate needle placement accuracy. Location of the needle, direction of contrast flow, the rate of conversion to an anterior portal, and adverse events were analyzed.

RESULTS

A fluoroscopic arthrogram was obtained after the first attempt in nine patients (90%). One patient (10%) was converted to the anterior approach due to inability to obtain the expected arthrogram. Two patients (20%) demonstrated mild adverse events.

CONCLUSION

Ultrasound-guided posterior approach hip injection is accurate and without serious adverse events in our study. The posterior approach can be considered as an alternative approach for patients who cannot tolerate or may have technical difficulty with an anterior approach.

Intra-articular corticosteroids associated with increased risk of total hip arthroplasty at 5 years

BACKGROUND

Intra-articular corticosteroid injections are commonly administered for hip pain. However, guidelines are conflicting on their efficacy, particularly in patients without arthritis. This study assessed for an association of corticosteroid injections and the incidence of total hip arthroplasty at 5 years.

METHODS

Patients with a diagnosis of hip pain without femoroacetabular osteoarthritis who were administered an intra-articular corticosteroid injection of the hip within a 2-year period were identified from the Mariner PearlDiver database. Patient were matched to patients with a diagnosis of hip pain who did not receive an injection. 5-year incidence of total hip arthroplasty was compared between matched patients who received an intra-articular corticosteroid injection and those who did not.

RESULTS

2,540,154 patients diagnosed with hip pain without femoroacetabular arthritis were identified. 25,073 (0.9%) patients received a corticosteroid injection and were matched to an equal number of control patients. The incidence of total hip arthroplasty (THA) at 5-year-follow up was significantly higher for the corticosteroid cohort compared to controls (1.1% vs. 0.5%; p < 0.001). The incidence and risk of THA increased along with number of injections (1 injection: 0.8%, OR 1.37; 95% CI, 1.34-1.42; p < 0.001, 2 injections: 1.1%; OR 1.45; CI, 1.40-1.50; p < 0.001, ⩾3 injections: 1.5%; OR 1.48; CI, 1.40-1.56; p < 0.001).

CONCLUSIONS

There may be a dose-dependent association of corticosteroid injections and a greater risk of total hip arthroplasty at 5 years. These results along with the conflicting guidelines on the efficacy of intra-articular steroids for hip pain should prompt physicians to consider osteoarthritis progression that may occur in the setting of corticosteroid injections in non-arthritic hips.

Accuracy of Intraarticular Injections: Blind vs. Image Guided Techniques-A Review of Literature

Intra-articular injections are widely used for diagnostic and therapeutic purposes of joint pathologies throughout the body. These injections can be performed blind by utilizing anatomical landmarks or with the use of imaging modalities to directly visualize the joint space during injections. This review of the literature aims to comprehensively identify differences in the accuracy of intra-articular injections via palpation vs. image guidance in the most commonly injected joints in the upper and lower extremities. To our knowledge, there are no such comprehensive reviews available. A narrative literature review was performed using PubMed and Google Scholar databases to identify studies focusing on the accuracy of blind or image-guided intra-articular injections for each joint. A total of 75 articles was included in this review, with blind and image-guided strategies being discussed for the most commonly injected joints of the upper and lower extremities. Varying ranges of accuracy with blind and image-guided modalities were found throughout the literature, though an improvement in accuracy was seen in nearly all joints when using image guidance. Differences are pronounced, particularly in deep joints such as the hip or in the small joints such as those in the hand or foot. Image guidance is a useful adjunct for most intra-articular injections, if available. Though there is an increase in accuracy in nearly all joints, minor differences in accuracy seen in large, easily accessed joints, such as the knee, may not warrant image guidance.

Pain After Preoperative Ultrasound Guided Hip Injections for Total Hip Arthroplasty: A Pilot Randomized Controlled Trial

Introduction. Hip replacement is a frequently performed and highly successful treatment for patients with end stage osteoarthritis. Advances in technique and pain management have allowed for rapid mobilization and early discharge after surgery. We hypothesize that pre-incision intra-articular injection of local anesthetic with epinephrine under image guidance combined with post incision peri-articular injection (PAI) may be more effective than PAI alone. Methods. A prospective, randomized, controlled, comparative investigation at a single institution of 41 patients undergoing THA who received standard 30 mL post-arthrotomy, PAI of ropivacaine with epinephrine under direct visualization after prosthesis implantation before closure or an equivalent dose divided into a 10 mL pre-incision, ultrasound guided intra-articular injection and a 20 mL post-arthrotomy PAI. Results. 42 patients were included in this study before its early conclusion with 22 patients in the treatment group and 20 in the control group. There were no significant differences in age, BMI or ASA scores. Additionally, there were no significant differences noted when comparing groups by postoperative outcome measures including OMME, EBL, OR time, PACU minutes, and first and last PACU pain score. Furthermore, there were no significant differences in the PROMs evaluated. Discussion. The addition of ultrasound guided pre-incision intra-articular injection to the standard PAI had no benefit when compared with standard PAI during a THA. Portable mobile phone based ultrasound devices provide a cost effective way to perform musculoskeletal blocks, and further studies on their use and comparative accuracy is warranted. A novel technique for confirmation of injection location is described.

International consensus conference recommendations on ultrasound education for undergraduate medical students

OBJECTIVES

The purpose of this study is to provide expert consensus recommendations to establish a global ultrasound curriculum for undergraduate medical students.

METHODS

64 multi-disciplinary ultrasound experts from 16 countries, 50 multi-disciplinary ultrasound consultants, and 21 medical students and residents contributed to these recommendations. A modified Delphi consensus method was used that included a systematic literature search, evaluation of the quality of literature by the GRADE system, and the RAND appropriateness method for panel judgment and consensus decisions. The process included four in-person international discussion sessions and two rounds of online voting.

RESULTS

A total of 332 consensus conference statements in four curricular domains were considered: (1) curricular scope (4 statements), (2) curricular rationale (10 statements), (3) curricular characteristics (14 statements), and (4) curricular content (304 statements). Of these 332 statements, 145 were recommended, 126 were strongly recommended, and 61 were not recommended. Important aspects of an undergraduate ultrasound curriculum identified include curricular integration across the basic and clinical sciences and a competency and entrustable professional activity-based model. The curriculum should form the foundation of a life-long continuum of ultrasound education that prepares students for advanced training and patient care. In addition, the curriculum should complement and support the medical school curriculum as a whole with enhanced understanding of anatomy, physiology, pathophysiological processes and clinical practice without displacing other important undergraduate learning. The content of the curriculum should be appropriate for the medical student level of training, evidence and expert opinion based, and include ongoing collaborative research and development to ensure optimum educational value and patient care.

CONCLUSIONS

The international consensus conference has provided the first comprehensive document of recommendations for a basic ultrasound curriculum. The document reflects the opinion of a diverse and representative group of international expert ultrasound practitioners, educators, and learners. These recommendations can standardize undergraduate medical student ultrasound education while serving as a basis for additional research in medical education and the application of ultrasound in clinical practice.

Value of ultrasound-guided aspiration of hip arthroplasties performed in an orthopedic clinic by orthopedic surgeons

Background: Total joint arthroplasties continue to increase as do periprosthetic joint infections (PJIs). Ultrasound-guided aspiration can yield useful synovial fluid for analysis while avoiding radiation exposure. This study presents a high-yield, ultrasound-guided technique with analysis of aspiration results. Methods: All consecutive ultrasound-guided aspirations of hip arthroplasties performed from May 2016 through to April 2019 were retrospectively reviewed. Patient demographic information, component specifics, presence of draining sinus, and inflammatory markers were recorded. Results of aspiration including volume, appearance, lavage use, synovial fluid differential leukocyte count, synovial neutrophil percent, and culture results were recorded. Surgical results, specimen cultures, and surgeon description of purulence were recorded. Aspiration results were compared to the surgical specimen results in all patients who underwent reoperations. Results: Review of 349 hip aspirations demonstrated accuracy of 87 %, sensitivity of 83 %, specificity of 89 %, positive predictive value of 79 %, and negative predictive value 91 %. Surgical and aspiration cultures matched in 81 % of cases. Bloody aspirates and aspirates obtained after lavage had less accuracy at 69 % and 60 %, respectively. Specificity was 100 % for cultures obtained with lavage and 91 % for bloody aspirates. Synovial leukocyte count and neutrophil percentage was obtained in 85 % of aspirations, and cultures were obtained in 98 % of aspirates. Contamination rate was 2 %. Conclusion: Ultrasound-guided aspirations aid in the diagnosis of PJI. The use of lavage to obtain fluid is helpful when aspiration cultures are positive. Bloody aspirates are less accurate but have high specificity. A low contamination rate and 88 % accuracy results with this meticulous technique.

Acetabular labral tears in the adolescent athlete: results of a graduated management protocol from therapy to arthroscopy

This study sought to determine outcomes of a graduated management protocol from therapy to arthroscopy for adolescents presenting with hip pain and an associated acetabular tear. Thirty-seven hips with an MRI confirmed labral tear were prospectively enrolled in a graduated management protocol created for adolescents. The protocol began with activity modification and focused physical therapy. Patients with persistent symptoms were offered an intraarticular corticosteroid injection. Those with continued symptoms were treated with arthroscopic surgery. The modified Harris hip score (mHHS) and nonarthritic hip score (NAHS) were recorded at the initial visit. Patients were contacted by telephone at 1, 2, and 5 years from enrollment for repeat assessment with mHHS and NAHS. At presentation, the mean mHHS and NAHS for the entire cohort was 66.4  ±  11.4 and 70.2  ±  12.6, and these values improved significantly to 89.3  ±  10.6 and 87.0  ±  11.4 at a mean follow-up of 35.7  ±  18.3 months (range 11.7-64.4 months). Forty-two percent of hips were managed with physical therapy and activity modifications alone, 28% of hips progressed to a steroid injection but did not require surgery, and 31% required arthroscopic intervention. Seventy-three percent of hips treated with activity modification alone, 80% treated with an injection, and 82% of hips treated with arthroscopic repair met the minimal clinically significant difference (MCID) (P = 0.859). At an average of 36 months follow-up, the majority (78%) of adolescent patients with an acetabular labral tear will achieve the MCID utilizing a graduated management protocol.

Modern Suture Anchor Techniques for Gluteus Medius Tear Repair With Concomitant Total Hip Arthroplasty Using the Direct Anterior and Posterior Approaches

Gluteus medius (GM) tears are currently a well-established source of pain and disability. However, their role in primary total hip arthroplasty (THA) in the setting of osteoarthritis (OA) has been underexamined in the literature. The purpose of this study was to report on short-term patient-reported outcome measurements (PROMs) for patients who underwent concomitant primary THA and GM repair. Data were prospectively collected from September 2011 and June 2017. Inclusion criteria were primary THA along with concomitant GM repair and complete follow-up for the Harris Hip Score, Forgotten Joint Score 12, Veterans RAND 12-item Health Survey both Physical and Mental, 12-item Short Form Survey both Physical and Mental (SF-12 P and SF-12 M), visual analog scale for pain, and patient satisfaction. Patients were excluded if they did not have follow-up. Thirty patients (30 hips) were included. Mean follow-up was 24.2±19.3 months. Twenty-nine (96.7%) patients were female. Mean age was 65.2±7.4 years. Mean body mass index was 31.1±5.9 kg/m². The posterior approach was used for 16 (53.3%) cases and the anterior approach for the remaining 14 (46.7%). Two (6.7%) patients had a less than 25% tear, 7 (23.3%) had a 25% to 50% tear, 14 (46.7%) had a greater than 50% tear, and 7 (23.3%) had a full-thickness tear. All PROMs except SF-12 M demonstrated significant improvement at latest follow-up. Patients who underwent THA with either the anterior or the posterior approach with concomitant GM repair using modern suture anchor techniques reported favorable PROMs at short-term follow-up. [Orthopedics. 2021;44(5):e653-e660.].

Trends in Utilization of Image Guidance for Hip Joint Injections

OBJECTIVE

This study aims to evaluate trends in utilization of image guidance for intraarticular hip injections and to compare the cost efficiency of ultrasound-, fluoroscopic-, and landmark-guided injections in the management of hip osteoarthritis (OA) and femoroacetabular impingement (FAI).

DESIGN

Retrospective descriptive epidemiology study.

SETTING

The information was collected from Humana private payer insurance claims database encompassing all practice settings.

PATIENTS OR PARTICIPANTS

A total of 302 855 patients for years 2007 to 2015.

INTERVENTIONS OR ASSESSMENT OF RISK FACTORS OR INDEPENDENT VARIABLES

Primary diagnosis of hip OA or FAI.

MAIN OUTCOME MEASURES

Injection type [corticosteroid (CS) or hyaluronic acid (HA)], imaging modality (landmark, ultrasound, or fluoroscopic guidance), and costs.

RESULTS

Landmark-guided CS and HA injections for the management of hip OA decreased, whereas fluoroscopic and ultrasound guidance increased. Similar trends were demonstrated in the management of FAI using CS. In the management of FAI using HA, landmark- and ultrasound-guided injections decreased and fluoroscopic-guided injections increased. Cost analysis revealed lower reimbursement of landmark and ultrasound guidance compared with fluoroscopic guidance.

CONCLUSIONS

During the study period, there was an increase in the use of image guidance and decline in landmark guidance for the treatment of OA and FAI using CS and HA. Fluoroscopic guidance demonstrated increased reimbursement compared with landmark and fluoroscopic guidance. There is an opportunity to mitigate cost and reduce radiation exposure by using ultrasound-guided injections rather than fluoroscopic guidance.

Image-Guided Intra-articular Hip Injections and Risk of Infection After Hip Arthroscopy

BACKGROUND

Although intra-articular injections are important in the management of patients who may later undergo hip arthroscopy, conflicting data are available regarding the safety of such injections when administered within 3 months of surgery. Furthermore, despite the increasing use of image-guided intra-articular hip injections, it is unknown whether the type of imaging modality used is associated with infection after hip arthroscopy.

PURPOSE

To assess the risk of infection associated with image-guided intra-articular injections before hip arthroscopy and, secondarily, compare that risk between ultrasound (US) and fluoroscopic (FL) guidance.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This was a retrospective cohort study of patients in a large national insurance database who underwent hip arthroscopy between 2007 and 2017. Patients were required to have continuous enrollment from at least 1 year before to 6 months after hip arthroscopy. Patient age, sex, geographic region, medical history, surgical details, and hip injections were collected. Patients who underwent injection ≤3 months preoperatively and >3 to ≤12 months preoperatively were compared with patients who did not undergo preoperative injection. Bivariate analyses and multivariable logistic regressions were used to assess the association between ipsilateral preoperative hip injection and surgical site infection within 6 months of surgery.

RESULTS

We identified 17,987 patients (36.3% female; mean ± SD age, 37.6 ± 14.0 years) undergoing hip arthroscopy, 2276 (12.7%) of whom had an image-guided hip injection in the year preceding surgery (53.0% FL). Patients who underwent intra-articular injection ≤3 months preoperatively had similar infection rates to patients who did not undergo preoperative injection in the year before surgery for both the FL (0.46% vs 0.46%; P≥ .995) and the US cohorts (0.50% vs 0.46%; P = .76). Results persisted in adjusted analysis (FL ≤3 months: OR, 1.04; 95% CI, 0.32-3.37; P = .94; US ≤3 months: OR, 1.19; 95% CI, 0.36-3.90; P = .78). Similar results were seen for patients undergoing injections >3 to ≤12 months preoperatively.

CONCLUSION

Postoperative infection was rare in patients undergoing intra-articular hip injection ≤3 months before hip arthroscopy and was no more common than in patients not undergoing preoperative injection. Moreover, no differences were seen in infection risk between US and FL guidance. Although intra-articular hip injections should always be administered with careful consideration, these results do not suggest that these injections are uniformly contraindicated in the 3 months preceding hip arthroscopy.

The orthopaedic nurse practitioner: Breaking tradition to fill gaps in care delivery through varied scopes of practice

BACKGROUND

Musculoskeletal conditions are the world's fourth largest burden of disease, accounting for more than 50% of chronic health conditions in the population aged >50 years (Briggs et al., 2016). This increasing burden is due to a progressively overweight, sedentary and ageing population and is often poorly recognised as a priority globally in an under-resourced health care system. This article reviews the current literature to identify where Orthopaedic Nurse Practitioners (ONPs) currently fill gaps in care delivery through varied scopes of practice in musculoskeletal trauma, degenerative disease, tumour and bone health. The varied scopes of practice include, fracture management, surgical assisting, performing surgical and/or advanced clinical procedures, prescribing treatment for bone health, conducting home visits and managing ONP led outpatient clinics. The article will outline current ONP roles in orthopaedic trauma, pain management, fragility hip fractures, osteoporosis, bone and soft tissue sarcoma and surgical assisting which effectively address long waiting lists, gaps in care delivery and reduce costs currently being managed by the health care system.

METHOD

A brief search of the literature published from January 2008-January 2020 on CINAHL, Cochrane Library, MEDLINE, Joanna Briggs Institute, Ovid, PubMed, Embase and Pro Quest databases was undertaken using key words Orthopaedic Nurse Practitioner, Advanced Practice Nurse (APN), musculoskeletal health, bone health, nurse-led and nurse specialist.

CONCLUSION

ONPs offer an innovative, viable and cost-effective solution to providing comparable, effective and efficient care with varied scopes of practice and valuable experience in both the inpatient and outpatient settings.

Repair of Symptomatic Partial Gluteus Medius Tear During Total Hip Arthroplasty Through the Direct Anterior Approach

Gluteus medius (GM) tears are a well-established source of pain and disability. Considering previous studies, which have reported rates of incidental GM tears in 20% of patients undergoing primary total hip arthroplasty (THA) and a 3-fold greater rate in elderly female patients, additional focus should be placed on identifying treatment options. The direct anterior approach (DAA) for primary THA has gained popularity within the past few years. However, there has been a paucity in the literature on how to address symptomatic and partial GM tears through this approach. The purpose of this Technical Note is to describe a method to repair partial GM tears during primary THA using the DAA.

Current Variation in Joint Aspiration Practice for the Evaluation of Pediatric Septic Arthritis

Pediatric septic arthritis (SA) is a condition that can be associated with significant morbidity. Although previous research has been on predictive care pathways, scrutiny of the literature continues to reveal wide differences in the patient evaluation and management. The purpose of this study was to define the differences in joint aspiration for the evaluation of pediatric SA across pediatric tertiary care institutions in the United States.

Clinical and patient-reported outcomes after image-guided intra-articular therapeutic hip injections for osteoarthritis-related hip pain: a retrospective study

OBJECTIVE

To evaluate change in patient-reported outcomes following image-guided intra-articular therapeutic steroid hip injections for pain and assess correlations of outcomes with patient- and injection-specific factors.

MATERIALS AND METHODS

We retrospectively reviewed consecutive patients treated for hip pain who completed outcomes assessments from October 2011 to September 2017 at an outpatient orthopedic surgery clinic. Only patients with radiographic hip osteoarthritis (Tönnis grade ≥ 1) who underwent steroid hip injections were included. Outcomes assessments included EuroQol-5 domain (EQ5D), EQ5D-visual analog scale (VAS), and hip disability and osteoarthritis outcome score (HOOS), obtained before and within 1-6 months post-injection. Among 113 patients who completed surveys, the mean age was 59 years (±13.7 years), including 77 women (68%) and 36 men (32%). Time to repeat injection or arthroplasty was recorded. Exact Wilcoxon signed rank test assessed score differences and Spearman correlation, Kruskal-Wallis, and Mann-Whitney tests assessed correlations.

RESULTS

Of 113 patients, 34 had outcomes measured at <8 weeks and 79 at ≥8 weeks. There was no significant change among any of the patients, short- or long-term follow-up subgroups in EQ5D (p = 0.450, 0.770, 0.493 respectively), EQ5D-VAS (p = 0.581, 0.915, 0.455), average-HOOS (p = 0.478, 0.696, 0.443) or total-HOOS (p = 0.380, 0.517, 0.423) scores. Forty-nine patients underwent hip arthroplasty within 1 year. Positive correlation was found between days from injection to surgery and change in EQ5D (r = 0.29, p = 0.025), average-HOOS (r = 0.33, p = 0.019), and total-HOOS (r = 0.37, p = 0.008).

CONCLUSION

We demonstrated no significant change in patient-reported outcomes measured at short- and long-term intervals up to 6 months after therapeutic steroid hip injections.

Efficacy of a non-image-guided diagnostic hip injection in patients with clinical and radiographic evidence of intra-articular hip pathology

The purpose of this study was to determine the likelihood of pain relief, as a measure of accurate diagnosis of intra-articular hip pathology and correct needle placement, with a non-image-guided intra-articular hip injection performed bedside in the clinic. A retrospective study of prospectively collected data was performed in a consecutive cohort of patients diagnosed with symptomatic intra-articular hip pathology who underwent a non-image-guided intra-articular injection in the clinic. All patients had clinical and radiographic evidence of hip impingement, hip instability, chondrolabral pathology, or other causes of intra-articular hip pain. A previously described technique for a non-image-guided hip injection was performed using 7-10 ml of 1% lidocaine for diagnostic evaluation with some patients receiving 2 ml of Kenalog^®-40 if clinically indicated. Ten minutes following each injection, the patient was asked to report the percent improvement in pain (from 0 to 100%) while physical examination and provocative tests were repeated. The final study cohort comprised 142 patients (161 injections). In three cases, patients were either unable to assess or quantify any change in pain level 10 min following the injection. In the remaining 158 hip injections, pain relief was noted in 156 cases (156/158, 98.7%), with at least 70% improvement in pain level noted in 152 cases (152/158, 96.2%). Average pain relief among all 158 injections was 89 ± 16%. A non-image-guided diagnostic intra-articular hip injection yields reliable short-term pain relief, simultaneously endorsing accurate diagnosis of hip pathology and intra-articular needle placement.

Retrospective Analysis of the Accuracy of Ultrasound-Guided Magnetic Resonance Arthrogram Injections of the Hip in the Office Setting

Background:

Ultrasound (US)–guided intra-articular hip injections have been proposed in the literature to be accurate, reliable, and safe alternatives to fluoroscopy-guided injections.

Purpose:

To evaluate the accuracy of US-guided magnetic resonance (MR) arthrogram injections of the hip performed in the office setting by a single orthopaedic surgeon and elucidate the potential effects that patient age, sex, and body mass index (BMI) have on contrast placement.

Study Design:

Case series; Level of evidence, 4.

Methods:

From a review of the senior author’s office database, 89 patients (101 hips) who had US-guided MR arthrogram injections performed between December 2014 and June 2016 were identified. Official radiology reports were evaluated to determine whether extra-articular contrast was noted. Patient variables, including BMI, age, and sex, were evaluated between patients who had inappropriately placed contrast and those who did not.

Results:

Of the 101 hip injections, there were 6 cases that demonstrated inadequate contrast placement within the joint, likely secondary to extravasation or incorrect placement; however, an MR arthrogram was adequately interpreted in all cases. There were no significant differences noted between those with appropriate versus inappropriate contrast placement when evaluating BMI (P = .57), age (P = .33), or sex (P = .67), and neither group had an adverse event.

Conclusion:

US-guided injections are safe and accurate alternatives to fluoroscopy-guided injections in the office setting, with 94% accuracy. Furthermore, BMI, age, and sex did not play a statistically significant role among patients with inappropriately placed contrast.