Peripheral Joint Injections.

Peripheral joint injections are a common interventional treatment of peripheral joint-mediated pain, including arthritis, tendinopathy, and bursitis that are not responsive to conservative management. Degenerative changes of articular joints are often related to these symptoms through chronic inflammatory changes, which typically arise due to repetitive trauma, autoimmune disease, or metabolic abnormalities. The primary diagnosis for degenerative disease in the peripheral joints is osteoarthritis but can also include rheumatoid arthritis, gout, and other less common etiologies. Chronic inflammatory damage to the articular surfaces and joint capsules can lead to pain and functional decline. As such, the use of peripheral joint injections after the failure of typical conservative treatment, including physical therapy and oral medications, is common. Although these injections are typically not curative in nature, their primary objective is to decrease pain to allow functional improvement concurrently with physical and pharmaceutical modalities. Common injectates used for peripheral joint injections include local anesthetic, corticosteroid, hyaluronic acid, platelet-rich plasma, and mesenchymal stromal cells.

Lumbar Spinal Stenosis and Potential Management With Prostaglandin E1 Analogs.

ABSTRACT: Lumbar spinal stenosis is one of the most commonly diagnosed spinal disorders worldwide and remains a major cause for surgery in older adults. Lumbar spinal stenosis is clinically defined as a progressive degenerative disorder with low back pain and associated neurogenic intermittent claudication. Conservative and surgical management of lumbar spinal stenosis has been shown to be minimally effective on its symptoms. A treatment option that has not been investigated in the United States is the utilization of prostaglandin E1 analogs, which have been used primarily in Japan for the treatment of lumbar spinal stenosis since the 1980s. The vasodilatory and antiplatelet aggregation effects of prostaglandin E1 presumably improve symptoms of lumbar spinal stenosis by increasing blood flow to the spinal nerve roots. This brief report examines the potential vascular pathology of lumbar spinal stenosis, reviews evidence on the use of prostaglandin E1 analog limaprost in Japan for lumbar spinal stenosis, and briefly discusses misoprostol as a possible alternative in the United States. The studies summarized in this report suggest that prostaglandin E1 analogs may provide benefit as a conservative treatment option for patients with lumbar spinal stenosis. However, higher-quality studies conducted in the United States and comparison with other currently used conservative treatments are required before it can be recommended for routine clinical use.

Cooled Radiofrequency Ablation of the Genicular Nerves for Chronic Pain due to Knee Osteoarthritis: Six-Month Outcomes.

OBJECTIVE: Determine outcomes of cooled radiofrequency ablation (C-RFA) of the genicular nerves for treatment of chronic knee pain due to osteoarthritis (OA). DESIGN: Cross-sectional survey. SETTING: Academic pain medicine center. SUBJECTS: Consecutive patients with knee OA and 50% or greater pain relief following genicular nerve blocks who underwent genicular nerve C-RFA. METHODS: Survey administration six or more months after C-RFA. Pain numeric rating scale (NRS), Medication Quantification Scale III (MQSIII), Patient Global Impression of Change (PGIC), and total knee arthroplasty (TKA) data were collected. Logistic regression was used to identify factors that predicted treatment success. RESULTS: Thirty-three patients (52 discrete knees) met inclusion criteria. Thirty-five percent (95% confidence interval [CI] = 22-48) of procedures resulted in the combined outcome of 50% or greater reduction in NRS score, reduction of 3.4 or more points in MQSIII score, and PGIC score consistent with "very much improved/improved." Nineteen percent (95% CI = 10-33) of procedures resulted in complete pain relief. Greater duration of pain and greater than 80% pain relief from diagnostic blocks were identified as predictors of treatment success. The accuracy of the model was 0.88 (95% CI = 0.78-0.97, P < 0.001). CONCLUSIONS: Genicular C-RFA demonstrated a success rate of 35% based on a robust combination of outcome measures, and 19% of procedures resulted in complete relief of pain at a minimum of six months of follow-up. Report of 80% or greater relief from diagnostic blocks and duration of pain of less than five years are associated with high accuracy in predicting treatment success. Further prospective study is needed to optimize the patient selection protocol and success rate of this procedure.

Does Trainee Involvement in Fluoroscopic Injections Affect Fluoroscopic Time, Immediate Pain Reduction, and Complication Rate?

BACKGROUND: Patients have expressed concern about undergoing procedures involving trainees, even with direct attending physician supervision. Little literature has examined the effect of trainee involvement on patient outcomes. OBJECTIVE: We aimed to evaluate the effect of trainee involvement on patient complications, immediate pain reduction, and fluoroscopic time for different fluoroscopic injection types. DESIGN: Retrospective review. SETTING: Four academic outpatient institutions with Accreditation Council for Graduate Medical Education (ACGME)-accredited residency (physical medicine and rehabilitation, or anesthesiology) or fellowship (sports medicine or pain medicine) programs from 2000 to 2015. PATIENTS: All patients receiving fluoroscopically guided hip (HI), sacroiliac joint (SIJI), transforaminal epidural (TFEI), and/or interlaminar epidural injections (ILEI, performed at only 1 institution). METHODS: Outcome measures were examined based on the presence or absence of a trainee during the procedure. MAIN OUTCOME MEASUREMENTS: The primary outcome was the number of immediate complications, with secondary outcomes being fluoroscopic time per injection (FTPI) and immediate numeric rating scale percentage improvement. RESULTS: Trainees were involved in 67.0% of all injections (N = 7,833). Complication rates or improvements in numeric rating scale scores showed no significant differences with trainee involvement for any injection type (P > .05). Trainee involvement was associated with increased FTPI for ILEIs (18.2 ± 10.1 seconds with trainees versus 15.1 ± 8.5 seconds without trainees, P < .001), but not for HIs (P = .60) or SIJIs (P = .51). Trainee involvement with TFEIs was dependent on institution for outcome with respect to FTPI (P < .001), with 28.1 ± 17.9 seconds with trainees and 32.1 ± 22.1 seconds without trainees (P = 0.51). CONCLUSIONS: This large multicenter study of academic institutions demonstrates that trainee involvement in fluoroscopically guided injections does not affect immediate patient complications or pain improvement. Trainee involvement does not increase fluoroscopic time for most injections, although there is an institutional difference seen. This study supports the notion that appropriate trainee supervision likely does not compromise patient safety for fluoroscopically guided injections. LEVEL OF EVIDENCE: II.

The Impact of Body Mass Index on Fluoroscopy Time During Lumbar Epidural Steroid Injection; A Multicenter Cohort Study.

Objective: This study aimed to assess the relationship between BMI and fluoroscopy time during lumbar epidural steroid injections (LESIs) performed for lumbosacral radicular pain. Design: Multicenter retrospective cohort study. Setting: Three academic, outpatient pain treatment centers. Subjects: Patients who underwent fluoroscopically guided LESI. Methods: Mean and standard deviation (SD) fluoroscopy time were compared between patients with normal (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2) BMI. Statistical significance was set at P=0.01 due to multiple comparisons. Results: A total of 2,930 procedure encounters were included, consisting of 598 interlaminar LESIs and 2,332 transforaminal LESIs. Fluoroscopy time was significantly longer in the obese patients compared to normal and overweight patients during interlaminar LESI (P < 0.01). Fluoroscopy time was significantly longer with each increasing BMI category in during transforaminal LESI (P < 0.01). These relationships remained when a trainee was involved (P < 0.01; P<0.01), during repeat injections (P < 0.01; P < 0.01), and during bilateral transforaminal LESIs (P < 0.01). While longer fluoroscopy times were required in high BMI categories during L5-S1 transforaminal LESI (P < 0.01), there was no relationship between fluoroscopy time and BMI during L4-L5 and S1 transforaminal LESI (P = 0.02; P = 0.13). Fluoroscopy time during interlaminar LESI compared to transforaminal LESI was significantly lower within all BMI categories (all P<0.01). Conclusions: The findings of this study indicate that fluoroscopy time is increased during interlaminar LESIs and during L5-S1 transforaminal LESIs in patients who are obese. These relationships are not affected by injection number, performance of bilateral injections, or trainee involvement. Further study is needed to determine if this increase in fluoroscopy time is indicative of a clinically significant associated increase in radiation dose.

Is There a Relationship Between Body Mass Index and Fluoroscopy Time During Cervical Interlaminar Epidural Steroid Injections?

BACKGROUND: The challenge of obtaining medical imaging in individuals with higher body mass index (BMI) is described, but there is minimal data regarding the relationship between BMI and fluoroscopy time during cervical interlaminar epidural steroid injection (CIESI). OBJECTIVE: To determine the relationship between BMI and fluoroscopy time during CIESI. METHODS: Retrospective cohort study of patients who underwent fluoroscopically guided CIESI between January 2014 and February 2015 at an academic pain medicine center. Fluoroscopy time data were collected. Comparisons based on analysis of variance were made between patients with normal (<25.0 kg/m 2 ), overweight (25.0-29.9 kg/m 2 ), and obese (≥30.0 kg/m 2 ) BMI. RESULTS: Of 399 procedure encounters, 366 had documented BMI and fluoroscopy time data and were included for analysis. Mean age (± SD) in this cohort was 53 ± 13 years, including 189 females (52%) and 205 first-time injections. Mean fluoroscopy time for all injections was 18 ± 10 seconds. Separated by categorical BMI class, the mean fluoroscopy time was 18 ± 9 seconds for normal weight patients, 17 ± 10 seconds for overweight patients, and 20 ± 11 seconds for obese patients, respectively. Post hoc analysis showed that fluoroscopy time was significantly longer only in obese compared with overweight patients ( P = 0.02). Trainee involvement and first-time vs repeat injection did not significantly alter fluoroscopy time ( P = 0.17 and P = 0.12, respectively). CONCLUSIONS: The findings of this study indicate that BMI does not appear to have a clinically significant impact on fluoroscopy time during cervical interlaminar epidural steroid injection procedures. Future study is needed to directly quantify radiation exposure in patients and practitioners, as well as the associated health risk.