Artificial intelligence vs. radiologist: accuracy of wrist fracture detection on radiographs.

OBJECTIVE: To compare the performances of artificial intelligence (AI) to those of radiologists in wrist fracture detection on radiographs. METHODS: This retrospective study included 637 patients (1917 radiographs) with wrist trauma between January 2017 and December 2019. The AI software used was a deep neuronal network algorithm. Ground truth was established by three senior musculoskeletal radiologists who compared the initial radiology reports (IRR) made by non-specialized radiologists, the results of AI, and the combination of AI and IRR (IR+AI) RESULTS: A total of 318 fractures were reported by the senior radiologists in 247 patients. Sensitivity of AI (83%; 95% CI: 78-87%) was significantly greater than that of IRR (76%; 95% CI: 70-81%) (p < 0.001). Specificities were similar for AI (96%; 95% CI: 93-97%) and for IRR (96%; 95% CI: 94-98%) (p = 0.80). The combination of AI+IRR had a significantly greater sensitivity (88%; 95% CI: 84-92%) compared to AI and IRR (p < 0.001) and a lower specificity (92%; 95% CI: 89-95%) (p < 0.001). The sensitivity for scaphoid fracture detection was acceptable for AI (84%) and IRR (80%) but poor for the detection of other carpal bones fracture (41% for AI and 26% for IRR). CONCLUSIONS: Performance of AI in wrist fracture detection on radiographs is better than that of non-specialized radiologists. The combination of AI and radiologist's analysis yields best performances. KEY POINTS: • Artificial intelligence has better performances for wrist fracture detection compared to non-expert radiologists in daily practice. • Performance of artificial intelligence greatly differs depending on the anatomical area. • Sensitivity of artificial intelligence for the detection of carpal bones fractures is 56%.

Does load-bearing materials influence hip capsule thickness in total hip replacement? An MRI case-matched study.

BACKGROUND: Ceramic-on-ceramic (COC) total hip replacements (THR) have exhibited less instability and late dislocation. Hip capsule plays an important role in hip stability. Different surrounding soft tissue reactions have been observed according to the bearing material used but no study compared these data using MRI investigation. Therefore, we performed a retrospective case control study to compare hip capsule thicknesses according to the bearing materials in THR and in native hips. HYPOTHESIS: Hip capsule is thicker after COC THR compared to ceramic- or metal-on-polyethylene (PE) bearings, or native hips. MATERIALS AND METHOD: Magnetic resonance imaging (MRI) images, combined with a multi acquisition variable resonance image combination (MAVRIC) sequence, was used to measure the hip capsule thickness in 16 patients (29 hips) who had either COC (13 hips, median age at surgery: 64.8 years old, median follow-up at imaging: 2482 days), PE bearings (11 hips, median age at surgery: 48.4 years old (significantly different from COC THR), median follow-up at imaging: 1860 days (NS)), or a native hip with no implant (5 hips). Two independent radiologists measured capsular thicknesses in 4 different zones and were blinded regarding the bearing components. The imaged hips were classified into three groups: native, COC and PE. RESULTS: The COC THR group had the thickest capsules (median 7.0mm, range 2.9-15.5mm). This result was statistically significant (p<0.0001) when compared to PE THR (median 4.9mm, range 2.2-10.5mm), and to native hips (median 4.1mm, range 2.7-6.9mm) measurements, respectively. Furthermore, painful hips had thinner capsules (4.6mm, range 2-10.5) compared to not painful hips (6.8mm, range 2.3-15.5) (p=0.0006). DISCUSSION: This is the first in-vivo study measuring capsular thickness in THR with the objective of measuring variations according to the hip implant materials used. The results revealed a significantly thicker capsule for the COC bearing compared to either PE or native hips, and a thinner capsule in painful hips. LEVEL OF EVIDENCE: III, retrospective non-consecutive cohort study.

Clinical feasibility of 2D dynamic sagittal HASTE flexion-extension imaging of the cervical spine for the assessment of spondylolisthesis and cervical cord impingement.

PURPOSE: To assess the utility of a 2D dynamic HASTE sequence in assessment of cervical spine flexion-extension, specifically (1) comparing dynamic spondylolisthesis to radiographs and (2) assessing dynamic contact upon or deformity of the cord. METHODS: Patients with a dynamic flexion-extension sagittal 2D HASTE sequence in addition to routine cervical spine sequences were identified. Static and dynamic listhesis was first determined on flexion-extension radiographs reviewed in consensus. Blinded assessment of the dynamic HASTE sequence was independently performed by 2 radiologists for (1) listhesis and translation during flexion-extension and (2) dynamic spinal cord impingement (cord contact or deformity between neutral, flexion and extension). RESULTS: 32 scans in 32 patients (9 males, 23 females) met inclusion criteria acquired on 1.5 T (n = 15) and 3 T (n = 17) scanners. The mean acquisition time was 51.8 s (range 20-95 seconds). Dynamic translation was seen in 14 patients on flexion-extension radiographs compared to 12 (reader 1) and 13 (reader 2) patients on HASTE, with 90.6 % agreement (K = 0.83; p = 0.789). In all cases dynamic listhesis was ≤3 mm translation with one patient showing dynamic listhesis in the range 4-6 mm. Four cases (13 %) demonstrated deformity of the cord between flexion-extension, not present in the neutral position. For cord impingement there was strong inter-reader agreement (K = 0.93) and the paired sample Wilcoxon signed rank test found no significant difference between the impingement scores of the two readers (p = 0.787). CONCLUSIONS: A sagittal dynamic flexion-extension HASTE sequence provides a rapid addition to standard MRI cervical spine protocols, which may useful for assessment of dynamic spondylolisthesis and cord deformity.

Ultrasound-guided Therapeutic Injection and Cryoablation of the Medial Plantar Proper Digital Nerve (Joplin's Nerve): Sonographic Findings, Technique, and Clinical Outcomes.

RATIONALE AND OBJECTIVES: The medial plantar proper digital nerve, also called Joplin's nerve, arises from the medial plantar nerve, courses along the medial hallux metatarsophalangeal joint, and can be a source of neuropathic pain due to various etiologies, following acute injury including bunion surgery and repetitive microtrauma. We describe our clinical experience with diagnostic ultrasound assessment of Joplin's neuropathy and technique for ultrasound-guided therapeutic intervention including both injection and cryoablation over a 6-year period. MATERIALS AND METHODS: Retrospective review of all diagnostic studies performed for Joplin's neuropathy and therapeutic Joplin's nerve ultrasound-guided injections and cryoablations between 2012 and 2018 was performed. Indications for therapeutic injection and cryoablation, were recorded. Studies were assessed for sonographic abnormalities related to the nerve and perineural soft tissues. Post-treatment outcomes including immediate pain scores, clinical follow-up, and periprocedural complications were documented. RESULTS: Twenty-four ultrasound-guided procedures were performed, including 15 perineural injections and nine cryoablations. With respect to sonographic abnormalities, nerve thickening (33%) and perineural hypoechoic scar tissue (27%) were the most common findings. The mean pain severity score prior to the therapeutic injection was 6.4/10 (range 4-10) and 0.25/10 (range 0-2) following the procedure; mean follow-up was 26.2 months (range 3-63 months). All of the cryoablation patients experienced sustained pain relief with a mean length follow-up of 3.75 months (range 0.2-10 months). CONCLUSION: Therapeutic injection of Joplin's nerve is a safe and easily performed procedure under ultrasound guidance, with high rates of immediate symptom improvement. For those experiencing a relapse or recurrent symptoms, cryoablation offers an effective secondary potential treatment option.

Wireless powering of e-swimmers.

Miniaturized structures that can move in a controlled way in solution and integrate various functionalities are attracting considerable attention due to the potential applications in fields ranging from autonomous micromotors to roving sensors. Here we introduce a concept which allows, depending on their specific design, the controlled directional motion of objects in water, combined with electronic functionalities such as the emission of light, sensing, signal conversion, treatment and transmission. The approach is based on electric field-induced polarization, which triggers different chemical reactions at the surface of the object and thereby its propulsion. This results in a localized electric current that can power in a wireless way electronic devices in water, leading to a new class of electronic swimmers (e-swimmers).