Society of Interventional Radiology Research Reporting Standards for Genicular Artery Embolization.

Genicular artery embolization (GAE) is an emerging, minimally invasive therapy to address the global burden of knee osteoarthritis (OA) and the unmet needs for medically refractory disease. Although total knee arthroplasty has been a standard intervention for severe cases, GAE is developing into a promising alternative, particularly for patients ineligible for or unwilling to undergo surgery. GAE targets the inflammatory cascade underlying OA pathophysiology by arresting neoangiogenesis and preventing pathological neoinnervation, offering potential pain relief. Although early studies have established safety and short-term effectiveness, ensuing studies are needed to validate long-term safety, durability, and comparative effectiveness and to optimize patient selection, embolic agent selection, and administration techniques. Standardized reporting guidelines are therefore essential to enhance transparency and reproducibility across clinical trials, facilitating data aggregation and comparison. This Society of Interventional Radiology (SIR)-endorsed reporting standards consensus document provides a framework to harmonize future research efforts and to improve the interpretation of outcomes.

Transarterial Embolization for Refractory Overuse Sports Injury: Pictorial Case Reports.

Transarterial embolization for the treatment of chronic musculoskeletal diseases is gaining increasing interest in the field of interventional radiology. Overuse sports injury is defined as an injury occurring in the absence of a single, identifiable traumatic cause. In the treatment of this condition, there is a need for reliable results and a quick return to activity. Minimally invasive treatments with short periods of missed practice are required. Intra-arterial embolization has the potential to meet this need. In this article, we describe cases of embolization for refractory overuse sports injuries including patellar tendinopathy, pes anserine, plantar fasciitis, triangular fibrocartilage complex injury, hamstring injury, infrapatellar fat pad inflammation, Achilles tendinopathy, delayed union metatarsal bone fracture, lumbar spondylolysis, and repetitive hamstrings strain.

Intra-Arterial Injection of Temporary Embolic Material Through a Needle Inserted into the Radial or Ulnar Artery for Distal and Proximal Interphalangeal Joint Osteoarthritis: A Retrospective Study of 92 Patients.

PURPOSE: To assess the efficacy and safety of intra-arterial injection of imipenem/cilastatin sodium (IPM/CS) via a needle placed into the radial artery or ulnar artery (RA/UA) for distal interphalangeal and proximal interphalangeal joint osteoarthritis (DIP/PIP-OA). MATERIALS AND METHODS: This is a retrospective single-arm cohort study. Ninety-two patients [92% women, mean (SD) age 55(8.3) years] with a primary DIP/PIP-OA meet the American College of Rheumatology criteria for hand osteoarthritis with pain ≥ 4 on the 0-10 numeric rating scale (NRS) were enrolled. All procedures were performed by injecting IPM/CS through a 24-gauge needle percutaneously inserted into the RA/UA. Two procedures were planned; the second procedure was scheduled 1-2 months after the first. NRS, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, Patient Global Impression of Change (PGIC) scale, and procedure-related adverse events were evaluated. RESULTS: Technical success, defined as injection of IPM/CS into the RA/UA, was achieved in all patients. Clinical success, defined as a reduction of 2 points or more in the NRS at 12 months, was 77% (95% confidence interval 68-85%). The NRS improved from the baseline to 3, 6, and 12 months (7.8 ± 1.6 vs. 3.8 ± 2.6, 3.9 ± 2.7, and 4.0 ± 2.8, respectively, all p < 0.001). The QuickDASH score improved from the baseline to 12 months (27 ± 15 vs. 19 ± 17, p < 0.001) respectively. No major adverse events were observed. CONCLUSIONS: Intra-arterial injection of IPM/CS is a feasible treatment option for DIP/PIP-OA.

Elbow Artery Embolization for Lateral Epicondylitis.

Lateral epicondylitis, also known as tennis elbow, is characterized by a low-grade inflammatory process in the lateral aspect of the elbow. Symptoms are typically treated conservatively, and most patients show resolution or improvement of symptoms within a few months. For those with refractory symptoms, treatment options are limited with questionable benefit. Embolization of the arteries supplying the elbow decreases the neo-vascularity seen in epicondylitis. The procedure may result in marked improvement in pain and function, which has shown to be durable.

Two-year outcomes comparing Embosphere® microspheres versus Imipenem Cilastatin for genicular artery embolization in patients with moderate to severe knee osteoarthritis.

BACKGROUND: Genicular artery embolization (GAE) is a novel technique and has the potential to provide midterm relief of pain for patients with mild-to-moderate knee osteoarthritis resistant to conservative management. This study compares the efficacy and safety of trisacryl gelatin microspheres to Imipenem/Cilastatin particles for GAE with 2 years of clinical follow-up. METHODS: In this retrospective study, eight patients with knee osteoarthritis (11 knees) who underwent GAE with 100-300 µm trisacryl gelatin microspheres particles were compared with six patients (nine knees) who underwent GAE with Imipenem/Cilastatin particles. Clinical outcomes were evaluated at 3-month and 24-month follow-ups and compared to baseline using the WOMAC questionnaire. RESULTS: The median follow-up was 796 days (range: 736-808). There were no significant differences in clinical outcome measures at the 3-month or 24-month follow-up. Both embolic materials resulted in a decrease in Pain WOMAC and Total WOMAC scores at 3 months (p < 0.05), and the effect of treatment on Pain WOMAC and Total WOMAC score reduction was sustained until the 24-month follow-up (p < 0.05). Minor events (Clavien-Dindo classification grade I) included transient cutaneous color change (n = 3) and transient leg numbness (n = 1) after embolization with trisacryl gelatin microspheres particles (p = 0.08). All minor adverse events resolved spontaneously. There were no major adverse events. CONCLUSION: One hundred to three hundred µm trisacryl gelatin microspheres particles can be considered for genicular artery embolization and is comparable to Imipenem/Cilastatin particles in pain reduction of moderate to severe knee osteoarthritis. A sustained effect is observed for up to 2 years of follow-up.

Alteration of chronic inflammatory status by transarterial embolization in frozen shoulder evaluated by fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography.

BACKGROUND: Frozen shoulder (FS) is speculated to have an inflammatory etiology. On angiography, abnormal angiogenesis is observed around the affected shoulder, suggesting a possible source of inflammation and pain. The effectiveness and safety of transarterial embolization (TAE) targeting abnormally proliferating blood vessels have been reported. This study investigated changes in chronic inflammatory and hypoxic status before and after TAE in FS by [18F]-fluoro-2-deoxyglucose (FDG) positron-emission tomography/computed tomography as a possible mechanism of the therapeutic response to TAE. METHODS: Fifteen patients with unilateral FS, persistent for more than 6 months, who were refractory to conservative treatments, underwent TAE using the temporary embolic agent imipenem/cilastatin. Patients underwent positron-emission tomography/computed tomography with FDG (as a biomarker of inflammation) before and 8 weeks after TAE. Regional uptake was evaluated by the maximum standardized uptake value. The lesion-side-to-(contralateral-) normal-side uptake ratio was also calculated. Pain and functional scales, range-of-motion, and laboratory tests, including white blood cell, C-reactive protein, interleukin 6, vascular endothelial growth factor, and tumor necrosis factor α were evaluated. RESULTS: On FDG-PET, the average maximum standardized uptake value of the lesion-side was significantly greater than that of the normal-side (maximum standardized uptake value before TAE: 3.11 ± 1.25 vs 1.95 ± 1.15, P = .0001; 8-weeks post-TAE: 2.36 ± 0.74 vs 1.78 ± 0.69, P = .0002). The mean lesion-side-to-(contralateral-) normal-side uptake ratios before TAE (1.71 ± 0.60) decreased after TAE (1.37 ± 0.29, P = .011). The decrease of FDG uptake (-21.1 ± 12.2%) showed a significant correlation with the change in the pain scale score (r = -0.56, P = .039) and extension score (r = -0.59, P = .026). CONCLUSION: Chronic inflammation in FS, as demonstrated by FDG uptake, was decreased after TAE. Thus, chronic inflammation is likely to be an underlying mechanism that should be targeted for symptomatic improvement of frozen shoulder.

Genicular artery embolization as a treatment for refractory osteoarthritis related knee pain.

Genicular artery embolization (GAE) is a minimally invasive outpatient therapy for osteoarthritis (OA) related knee pain, refractory to conservative management. This intervention targets neovasculature which arises in the setting of angiogenesis in OA. Various clinical trials highlighted in this manuscript suggest that GAE is effective in durably reducing OA-related knee pain, with a limited adverse event profile. This review also explores the clinical evaluation of GAE candidates, genicular artery anatomy, technical components of the procedure, and imaging from various GAE embolizations. It also discusses future directions for research which may illuminate predictors of clinical success as well as avenues for evolution in the GAE treatment.

Transarterial Embolization of Neovascularity for Refractory Nighttime Shoulder Pain: A Multicenter, Open-Label, Feasibility Trial.

PURPOSE: To assess the feasibility of transarterial embolization (TAE) for recalcitrant nighttime shoulder pain in a multicentric study. MATERIALS AND METHODS: This prospective, open-label, feasibility trial included 100 patients treated at 5 institutions. TAE was performed in 76 patients with adhesive capsulitis (AC) and 24 patients with symptomatic rotator cuff tears (sRCTs). The ipsilateral radial artery was punctured, and imipenem/cilastatin sodium was infused as an embolic agent. Adverse events, 10 point pain numerical rating scale (NRS), range of motion (ROM) of the shoulder joint, and quality of life (via the EuroQol-5D [EQ-5D]) were evaluated. RESULTS: All patients exhibited neovascularity on baseline angiography, and all TAE procedures were performed successfully. No patient experienced a major adverse event. The mean nighttime pain NRS scores at baseline and 1, 3, and 6 months after TAE were 6.4 ± 2.2, 3.4 ± 2.6, 2.3 ± 2.5, and 1.6 ± 2.2, respectively (for all, P < .001). The mean ROM of anterior elevation at baseline and 1, 3, and 6 months after TAE were 97° ± 29°, 119° ± 28°, 135° ± 27°, and 151° ± 17°, respectively (for all, P < .001). The mean EQ-5D scores at baseline and 1, 3, and 6 months after TAE were 0.63 ± 0.17, 0.73 ± 0.16, 0.80 ± 0.17, and 0.84 ± 0.17, respectively (for all, P < .001). There was no significant difference in the clinical success rate between the AC and sRCT groups. CONCLUSIONS: TAE for nighttime shoulder pain caused by AC and sRCTs was feasible with sufficient safety and efficacy.

Transcatheter arterial embolization of abnormal neovessels in a swine model of knee arthritis.

BACKGROUND: In recent years, transcatheter arterial embolization (TAE) using imipenem/cilastatin (IPM/CS) has attracted attention as a treatment for relieving osteoarthritis (OA) pain. However, IPM/CS is not approved by Japanese medical insurance for use as an embolic material. Therefore, it is necessary to develop new embolic materials for TAE to relieve OA pain. The purpose of this study was to develop a swine model of knee arthritis and embolize abnormal neovessels (ANs) using two different embolic materials. We compared the embolic effects and tissue damage in knees. METHODS: Knee arthritis was induced by intra-articular injection of papain into 12 knees in six female swine. The swine were divided into two groups of three swine each (six knees per group) for embolization of ANs in the knees with either IPM/CS or soluble gelatin sponge particles (SGSs). Three days after embolization, we compared the embolic effects using angiography and the tissue damage histopathologically. RESULTS: ANs were observed in all 12 knees at 42 days after papain injection. The ANs disappeared and the patent arteries were recanalized 3 days after TAE in all 12 knees. Histopathological evaluation revealed synovitis changes, such as synovial thickening and inflammatory cell infiltration, in all 12 knees. There was no evidence of skin or muscle necrosis in either group. The appearance of ANs, recanalization of the parent arteries, and histopathological outcomes were not significantly different between the two groups. CONCLUSION: SGSs were as safe as IPM/CS for TAE of ANs in this swine model of knee arthritis.

Transcatheter Arterial Embolization Using Imipenem/Cilastatin Sodium for Chronic Low Back Pain Resistant to Conservative Treatment: A Pilot Study with 2-Year Follow-Up.

PURPOSE: To evaluate the safety and 2-year follow-up clinical outcomes of transcatheter arterial embolization (TAE) using imipenem/cilastatin sodium for chronic low back pain resistant to conservative treatment. MATERIALS AND METHODS: A retrospective review identified 14 patients who underwent TAE for chronic low back pain between October 2017 and August 2018. Patients with low back pain related to the facet or sacroiliac joint, lasting ≥ 6 months, refractory to ≥ 3 months of conservative treatment were eligible for TAE. Each patient received embolization of feeding arteries of painful regions. The changes in brief pain inventory (BPI) scores, adverse events, and the Oswestry Disability Index (ODI) were evaluated at baseline and 1, 3, and 24 months after TAE. Clinical success was defined as BPI maximum pain intensity decrease of ≥ 2 and ODI decrease of ≥ 10 points from baseline. RESULTS: Follow-up data were available in 13 and 11 patients, at 3 and 24 months after embolization, respectively. Intention-to-treat clinical success was obtained in 11/14 (79%) of patients at 3 months and 8/14 (57%) of patients at 24 months after TAE. Mean BPI maximum pain intensity and ODI scores decreased significantly from baseline to 1, 3, and 24 months after treatment (7.6 vs.. 4.3, 3.4, and 4.1; 40.8 vs 21.5, 20.0, and 23.8, respectively; all P < 0.01). No major adverse events were associated with the procedures. CONCLUSION: TAE is one possible treatment option for patients with chronic low back pain refractory to conservative treatment.

Characteristics of the descending genicular artery blood flow velocity in patients with knee osteoarthritis.

BACKGROUND: In patients with knee osteoarthritis (KOA), the descending genicular artery (DGA) showed abnormal angiogenesis. However, the non-invasive assessment method of DGA remains unclear. The aim of this study was to clarify the characteristics of blood flow velocity of the DGA in patients with KOA and to examine the factors involved in the changes. METHODS: The KOA group included 22 knees of 22 patients with KOA (4 males, 18 females; mean age, 72.3 ± 7.5 years) and the control group included 22 knees (4 males, 18 females; mean age, 71.3 ± 5.4 years) of 22 healthy adults. The peak systolic blood flow velocity (PSV) in each group was measured using ultrasonography. The KOA group was classified into the effusion group and the non-effusion group based on observed effusion, and the PSV was compared between the two groups. The relationships between PSV and suprapatellar bursa intracavitary distance, pain, femorotibial angle, Japanese Knee Osteoarthritis Measure were also investigated. RESULTS: The PSV in the KOA group (51.5 ± 12.9 cm/s) was significantly higher than that in the control group (29.3 ± 4.4 cm/s) (P < 0.01). In the KOA group, PSV in the effusion group (55.5 cm/s (51.2-59.4 cm/s)) was significantly higher than that in the non-effusion group (39.1 cm/s (35.1-44.4 cm/s)) (P < 0.01). The PSV was positively and significantly correlated with both suprapatellar bursa intracavitary distance (r = 0.81: P < 0.01) and pain (r = 0.48: P < 0.05). CONCLUSIONS: The PSV measurement in the DGA is useful for the evaluation of non-invasive synovitis of patients with KOA.

Intra-Arterial Infusion of Imipenem/Cilastatin Sodium through a Needle Inserted into the Radial Artery as a New Treatment for Refractory Trapeziometacarpal Osteoarthritis.

PURPOSE: To evaluate the efficacy and safety of intra-arterial infusion of temporary embolic material with/without radiographic monitoring via a needle placed into the radial artery to occlude abnormal neovessels for trapeziometacarpal osteoarthritis. MATERIALS AND METHODS: Thirty-one patients having Eaton stage II or III osteoarthritis, with a symptom duration longer than 6 months, resistant to conservative therapy for at least 3 months were prospectively enrolled. All procedures were performed by infusing imipenem/cilastatin sodium through a 24-gauge needle that was percutaneously inserted into the radial artery. Seven patients underwent the procedure with fluoroscopy, and 21 patients underwent the procedure without fluoroscopy. The mean Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, numerical rating scale (NRS), and Patient Global Impression of Change (PGIC) scale were evaluated before and at 2, 6, and 24 months after the first procedure. RESULTS: Technical success was 100%. The mean procedure time (from the beginning of local anesthesia to the removal of needle) was 2.9 minutes ± 1.6. The QuickDASH score improved from the baseline to 2, 6, and 24 months (49.2 ± 11.2 vs 22.1 ± 11.2, 20.9 ± 16.6, and 19.5 ± 16.1, respectively, all P <.001). The NRS improved from the baseline to 2, 6, and 24 months (7.2 ± 1.1 vs 3.1 ± 1.8, 2.8 ± 2, and 2.5 ± 2.1, respectively, all P <.001). Improvement on PGIC was observed in 84%, 81%, and 77% of patients at 2, 6, and 24 months, respectively. No major adverse events were encountered. CONCLUSIONS: Intra-arterial infusion of temporary embolic material is a feasible treatment option for trapeziometacarpal osteoarthritis.

Intra-arterial Infusion of Temporary Embolic Material in a Patient with Plantar Fasciitis: A Case Report.

This case report concerns a 51-year-old woman with a 6-month history of severe right heel pain diagnosed as plantar fasciitis (PF) treated with intra-arterial infusion of imipenem/cilastatin (IPM/CS) through a 24G indwelling needle directly inserted into the posterior tibial artery (PTA). Angiography of the indwelling needle immediately before the infusion of IPM/CS demonstrated an increased number of abnormal vessels at the calcaneal attachment of the plantar fascia. Two procedures were planned: The first procedure was performed, and the second was performed 1 month after the first. A week after the first treatment, her pain gradually decreased. Three months after the first treatment, she no longer had difficulties with activities of daily living. Intra-arterial infusion of IPM/CS directly through an indwelling needle into the PTA represents a minimally invasive embolic treatment option for PF.

Association between Baseline Osteoarthritic Features on MR Imaging and Clinical Outcome after Genicular Artery Embolization for Knee Osteoarthritis.

PURPOSE: To explore the association between baseline osteoarthritis (OA)-related magnetic resonance (MR) imaging features and pain reduction after genicular artery embolization (GAE) in patients with mild-to-moderate symptomatic knee OA resistant to conservative therapy. MATERIALS AND METHODS: This was a retrospective analysis of patients with mild-to-moderate symptomatic knee OA treated with GAE using imipenem-cilastatin sodium. The clinical outcome was scored at baseline and 6 months after treatment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MR images were scored using the MR imaging osteoarthritis knee score. Linear regression was used to evaluate associations of before-treatment MR imaging scores with WOMACpain and WOMACtotal reduction after 6 months. RESULTS: Fifty-four patients (22.2% male; median age, 69.4 years; median WOMACpain at baseline, 12) were evaluated. Of all OA features scored, a higher cartilage full-thickness defect score showed the strongest association with less reduction of both WOMACpain (B,-0.63 [95% confidence interval (CI), -0.91 to -0.34]; P < .001) and WOMACtotal scores (B, -1.77 [95% CI, -2.87 to -0.67]; P < .001) following treatment. The presence of grade 2-3 effusion synovitis (B, -2.99 [95% CI, -5.39 to -0.60]) bone marrow lesions (B, -0.52 [95% CI, -0.86 to -0.19]), osteophytes (B, -0.21 [95% CI, -0.36 to -0.06]), and cartilage defect surface area score (B, -0.25 [95% CI -0.42 to -0.08]) all showed a significant association with less WOMACpain reduction (all P < .05). CONCLUSIONS: In patients with mild-to-moderate symptomatic knee OA treated with GAE, the presence and severity of full-thickness cartilage defects, effusion synovitis, bone marrow lesions, osteophytes, and cartilage surface area scores at baseline are associated with less favorable clinical outcomes at 6 months.

Effects of Transcatheter Arterial Microembolization on Persistent Trapezius Myalgia Refractory to Conservative Treatment.

PURPOSE: To evaluate the safety and efficacy of transcatheter arterial microembolization for patients with trapezius myalgia. MATERIALS AND METHODS: We retrospectively evaluated the prospectively collected data of patients with trapezius myalgia for > 6 months who were refractory to conservative treatment and were treated by transcatheter arterial microembolization between October 2017 and January 2019. Transcatheter arterial microembolization was performed using imipenem/cilastatin on the vessels of the transverse cervical artery, suprascapular artery, and circumflex scapular artery according to the region of pain. RESULTS: Forty-two patients were treated by transcatheter arterial microembolization and followed up for 6 months. No major adverse events occurred related to the procedures. The brief pain inventory worst pain scores significantly improved at 1, 2, 3, and 6 months after transcatheter arterial microembolization (8.6 ± 1.3 (before procedure) vs. 5.1 ± 2.9, 4.4 ± 2.9, 4.1 ± 2.8, and 3.9 ± 2.9, respectively, P < 0.001). The brief pain inventory pain interference scores, including general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life, also significantly decreased at 1, 2, 3, and 6 months after transcatheter arterial microembolization compared to those at baseline (all P < 0.01). The clinical success rate at 6 months after transcatheter arterial microembolization was 71.4% (95% confidence interval, 55.4-84.3%). CONCLUSION: Transcatheter arterial microembolization is a safe and effective treatment for persistent trapezius myalgia. Further evaluation with a control group is needed to confirm the effects of transcatheter arterial microembolization. LEVEL OF EVIDENCE: Level 4, Case Series.

Inflammation and Hypervascularization in a Large Animal Model of Knee Osteoarthritis: Imaging with Pathohistologic Correlation.

PURPOSE: To evaluate if synovial inflammation and hypervascularization are present in a dog model of knee osteoarthritis and can be detected on conventional magnetic resonance imaging (MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), contrast-enhanced magnetic resonance imaging (CE-MRI), and quantitative digital subtraction angiography (Q-DSA) imaging. MATERIALS AND METHODS: Six dogs underwent MRI and angiography of both knees before and 12 weeks after right knee anterior cruciate ligament injury. Synovial vascularity was evaluated on CE-MRI, DCE-MRI, and Q-DSA by 2 independent observers. Synovial inflammation and vascularity were histologically scored independently. Cartilage lesions and osteophytes were analyzed macroscopically, and cartilage volumetry was analyzed by MRI. Vascularity and osteoarthritis markers on imaging were compared before and after osteoarthritis generation, and between the osteoarthritis model and the control knee, using linear mixed models accounting for within-dog correlation. RESULTS: In all knees, baseline imaging showed no abnormalities. Control knees did not develop significant osteoarthritis changes, synovial inflammation, or hypervascularization. In osteoarthritis knees, mean synovial enhancement score on CE-MR imaging increased by 13.1 ± 0.59 (P < .0001); mean synovial inflammation variable increased from 47.33 ± 18.61 to 407.97 ± 18.61 on DCE-MR imaging (P < .0001); and area under the curve on Q-DSA increased by 1058.58 ± 199.08 (P = .0043). Synovial inflammation, hypervascularization, and osteophyte formations were present in all osteoarthritis knees. Histology scores showed strong correlation with CE-MR imaging findings (Spearman correlation coefficient [SCC] = 0.742; P = .0002) and Q-DSA findings (SCC = 0.763; P < .0001) and weak correlation with DCE-MR imaging (SCC = -0.345; P = .329). Moderate correlation was found between CE-MR imaging and DSA findings (SCC = 0.536; P = .0004). CONCLUSIONS: In this early-stage knee osteoarthritis dog model, synovial inflammation and hypervascularization were found on imaging and confirmed by histology.

Reliable patient-reported outcome measure and survivorship of UKA for primary spontaneous osteonecrosis.

PURPOSE: Primary Spontaneous osteonecrosis of the knee (SPONK) was a result of a subchondral insufficiency fracture based on histopathological examinations. There were few studies examining patients who underwent unicompartmental knee arthroplasty (UKA) for the treatment of primary SPONK. The aim of this study was to investigate (1) patient-reported outcome measure (PROM), (2) survivorship of revision as end point and (3) survivorship of complication as end point in patients with primary SPONK. METHODS: The clinical examinations of a consecutive series of 61 medial UKAs for primary SPONK of the medial femoral condyle from 2008 to 2012 were evaluated retrospectively at our institution. There were 18 males and 43 females with a mean age of 73.7 years (60-91). In all patients, preoperative radiographs were analyzed according to the stage of primary SPONK. We conducted Kaplan-Meier survival analyses using revision and complications for any reasons as the end point. RESULTS: Mean follow-up was 6.6 years (range 6-10). UKA using Physica ZUK (LIMA Corporate. UD, Italy) for SPONK improved patients' 2011 Knee Society symptom score, patient satisfaction, patient activities, EQ-5D and postoperative ranges of motion compared with their preoperative status (P < 0.01). Revision surgery was required in one knee (1.6%) due to postoperative fracture of the medial tibial plateau after a fall that occurred 6 months postoperatively. The projected rate of survivorship of UKA was 90.4% at 10 years (95% confidence interval 0.80-1). The projected rate of survivorship with complication at end point was 87.7% at 10 years (95% confidence interval 0.76-0.99). CONCLUSION: The present study demonstrated that primary spontaneous osteonecrosis of the knee (SPONK) can be successfully be treated with UKA at a mean follow-up of 6.6 years. LEVEL OF EVIDENCE: II.

Effect of Transcatheter Arterial Microembolization on Phantom Limb Pain Persisting for 17 Years.

Phantom limb pain is a frequent consequence of the amputation; currently available treatments are far from satisfactory. The present report describes a case in which transcatheter arterial microembolization had a remarkable curative effect on phantom limb pain persisting for 17 years. The patient began feeling phantom limb sensations and brief intermittent pain following lower limb amputation above the knee in 2001. The frequency, intensity, and duration of the pain increased over time, and it was resistant to conservative treatments. Following transcatheter arterial microembolization in 2018, patient immediately experienced marked improvement. The pain has been infrequent, much less intense, and did not interfere with daily life 6 months posttreatment. Transcatheter arterial microembolization could be an alternative treatment option for phantom limb pain. LEVEL OF EVIDENCE: IV, Case Report.

Transcatheter arterial embolization of abnormal vessels as a treatment for lateral epicondylitis refractory to conservative treatment: a pilot study with a 2-year follow-up.

BACKGROUND: Abnormal vessels and accompanying nerves are possible sources of pain with lateral epicondylitis. The purpose of this study was to describe the safety and efficacy of transcatheter arterial embolization (TAE) for lateral epicondylitis resistant to conservative treatment. METHODS: This prospective study was conducted in 24 patients with lateral epicondylitis resistant to conservative treatments for more than 3 months, with a symptom duration longer than 6 months, and with moderate to severe pain who were treated with TAE between March 2013 and October 2014. Two patients were lost to follow-up, and the remaining 22 patients were followed up for 2 years after TAE. RESULTS: Abnormal vessels were identified in all of the patients. No major adverse events were observed. The Quick Disabilities of the Arm, Shoulder and Hand scores at baseline significantly decreased at 1, 3, 6, and 24 months after treatment (50.8 vs 23.4, 8.3, 5.3, and 2.7, respectively; all P < .001). There was a statistically significant (P < .001) change from baseline to the last observed value in all of the clinical parameters, including visual analog scale pain score, Patient-Rated Tennis Elbow Evaluation score, and pain-free grip strength. Magnetic resonance images obtained 2 years after TAE showed an improvement in tendinosis and tear scores compared with baseline, and no patients showed bone marrow necrosis, obvious cartilage loss, or muscle atrophy. CONCLUSION: TAE could be one possible treatment option for patients with lateral epicondylitis that fails to improve with conservative treatments.