U Young Lee

Background: Lateral epicondylopathy is commonly approached as a tendinopathic disorder of the common extensor origin; however, persistent lateral elbow pain may also involve a superficial sensory nerve component related to the posterior antebrachial cutaneous nerve (PABCN). This proof-of-concept cadaveric anatomical feasibility study evaluated whether a single-window, humerus-parallel ultrasound-guided injectate pathway could simultaneously reach the superficial PABCN-related fascial plane and the common extensor origin. Methods: One fresh-frozen male cadaveric donor was used, and both elbows were injected under real-time ultrasound guidance. With the elbow flexed and the forearm pronated, the transducer was aligned parallel to the long axis of the humerus over the lateral epicondylar region. A 23-gauge, 6 cm needle was advanced in plane from distal to proximal over the common extensor aponeurosis, and 10 mL of 1% methylene blue was injected into each elbow. Layer-by-layer anatomical dissection was then performed by an anatomist who was not involved in the injection procedure. Gross linear dye spread was measured directly during dissection using the distal needle entry point as the reference point, and ruler-containing photographs were additionally reviewed using ImageJ software for supportive image-assisted assessment. Results: In both elbows, methylene blue stained the superficial PABCN-related fascial plane, including the anterior and posterior branches of the PABCN, and concomitantly covered the common extensor aponeurosis and lateral epicondylar enthesis. Dye spread measured approximately 10 cm proximally, 5 cm distally, and 4 cm anteriorly. No gross intra-articular dye deposition or focal intramuscular pooling was observed. Conclusions: This proof-of-concept cadaveric study demonstrates the anatomical plausibility of a single-window, enthesis-centered ultrasound-guided injectate pathway that includes both the superficial PABCN-related plane and the common extensor origin. These findings should be interpreted as descriptive anatomical feasibility observations and do not establish reproducibility across anatomical variants, clinical efficacy, safety, or procedural superiority.

The anterior labral–ligamentous complex (ALLC), formed by the integration of the anterior inferior glenohumeral ligament and anterior glenoid labrum, plays a critical role in shoulder stability and represents a potential target for regenerative injection therapy. However, precise ultrasound-guided targeting of this capsular–labral interface has not been anatomically validated. This feasibility cadaveric study evaluated the accuracy of ultrasound-guided in-plane injection directed at the ALLC at its glenoid attachment. A fresh-frozen human cadaver specimen was examined in the supine position with the shoulder in external rotation. Stepwise lateral-to-medial and cranial-to-caudal ultrasound scanning was performed to localize the ALLC. A 23-gauge needle was advanced in a cranial-to-caudal in-plane trajectory, and 1–2 mL of red filler was injected into the capsular–labral interface. Subsequent layer-by-layer dissection was conducted to assess injectate localization. In both shoulders (2/2), red filler was confined within the ALLC without extra-capsular leakage, diffuse intra-articular pooling, or neurovascular staining. These findings demonstrate the anatomical feasibility of ultrasound-guided targeted delivery to the anterior capsular–labral complex. This proof-of-concept study provides foundational anatomical validation for the development of regenerative injection protocols directed at the shoulder capsular–labral enthesis.

Background: Deep gluteal syndrome (DGS) has traditionally been attributed to sciatic nerve entrapment within the deep gluteal space. However, increasing evidence suggests that enthesopathy and soft tissue pathology of the short external rotators may also contribute to its pathogenesis. Conventional ultrasound-guided interventions primarily target the sciatic nerve through perineural hydrodissection (HD), which may not address enthesis-related pathology. However, the anatomical feasibility of delivering injectate along the deep gluteal fascial plane has not yet been investigated in cadaveric studies. Methods: This cadaveric anatomical demonstration evaluated whether an ultrasound-guided fascial plane injection within the deep gluteal space could simultaneously reach the enthesis of the short external rotators and the region of the sciatic nerve. Ultrasound scanning protocols were first demonstrated in a healthy volunteer to establish anatomical orientation for the injection pathway. Injection experiments were then performed in a fresh-frozen cadaver (83-year-old male) using a cranial-to-caudal in-plane approach. Ten milliliters of methylene blue dye was injected along the fascial plane overlying the short external rotator enthesis, followed by layer-by-layer cadaveric dissection to assess dye distribution. Results: Cadaveric dissection demonstrated that methylene blue injected along the deep gluteal fascial plane extended to the enthesis of the short external rotators and spread toward the surface of the sciatic nerve. Comparable distribution patterns were observed in both hips. These findings suggest that a single ultrasound-guided fascial plane injection trajectory may anatomically access both the enthesis region and the adjacent sciatic nerve within the deep gluteal space. Conclusions: Ultrasound-guided fascial plane HD in the deep gluteal space provides an anatomical pathway that can simultaneously access the enthesis of the short external rotators and the region of the sciatic nerve. This approach may represent a potential anatomical basis for a fascial plane-based intervention strategy in DGS. Further studies are required to evaluate in vivo behavior and clinical effectiveness.

Objectives: Anatomy remains a cornerstone of medical education, and emerging technologies are increasingly employed to enhance students’ understanding of complex spatial relationships. This study developed and implemented a case-based anatomy online module utilizing Magnetic Resonance Images (MRIs) of body donors and three-dimensional (3D) models to foster student engagement and promote hypothesis-driven learning. Methods: Students from the USA (n=40) and Türkiye (n=16) participated in virtual classrooms using distance education tools. Each case-based module included: Subject, Medical History, and Physical Exam, followed by Radiology and Pathology reports. Students generated diagnostic hypotheses during the virtual session, discussed findings in small groups, and accessed 3D segmented, photogrammetric, illustrative anatomical models and web-based MRIs. Results: Analysis of the results revealed significant differences in student responses between the JABSOM and Türkiye cohorts regarding the online learning modules. The Türkiye cohort consistently rated the modules more favorably across several key areas. Conclusion: Despite the differences, both cohorts expressed overall satisfaction with this online learning approach, indicating that the method was well-received across cultural and institutional contexts. This pilot study demonstrates the feasibility and effectiveness of integrating MRIs and 3D models into case-based anatomy instruction across international cohorts. The workflow offers a replicable model for future anatomy education, bridging traditional teaching methods with cutting-edge teaching tools.

This study investigated the effectiveness and safety of ultrasound-guided non-incisional thread trigger finger release on cadavers using a newly developed domestic thread (Smartwire-01). Ultrasound-guided non-incisional thread trigger finger release was performed on 12 fresh cadaveric hands, including 12 thumbs and 48 long fingers. Two experts, experienced in an ultrasound-guided thread transecting technique, performed the procedures independently. The distal-to-proximal and proximal-to-distal approaches were performed in 6 hands each to determine which is safer and more effective. After the procedure, anatomical analyses were conducted by a blinded anatomist. The presence of a dissected A1 pulley and any damage to adjacent structures were assessed. Among the 60 cadaveric digits, 52 (86.7%) showed complete transection of the A1 pulley. The success rate for the thumb (66.7%) was relatively lower than that of the other fingers (91.7%). The distal-to-proximal approach showed a higher success rate (96.7%) compared to the proximal-to-distal approach (76.7%), with a near-significant difference (p = 0.052). Anatomical analysis revealed clear and sharp incisional margins of the transected A1 pulley, with only 1 minor flexor tendon injury observed, which occurred with the proximal-to-distal approach. Ultrasound-guided non-incisional thread trigger finger release using Smartwire-01 is a safe and effective procedure when performed with the distal-to-proximal approach, particularly in long fingers.

Purpose The sacroiliac joint (SIJ), a synovial joint with irregular surfaces, is crucial for stabilizing the body and facilitating daily activities. However, recent studies have reported that 15–30% of lower back pain can be attributed to instability in the SIJ, a condition collectively referred to as sacroiliac joint dysfunction (SIJD). The aim of this study is to investigate how the morphological characteristics of the auricular surface may influence the SIJ range of motion (ROM) and to examine differences in SIJ ROM between females and males, thereby contributing to the enhancement of SIJD diagnosis and treatment. Methods We measured SIJ ROM using motion-analysis cameras in 24 fresh cadavers of Korean adults (13 males and 11 females). Using three-dimensional renderings of the measured auricular surface, we investigated the correlations between the morphological characteristics of the auricular surface and the ROM of the SIJ. Results The SIJ ROM was between 0.2° and 6.7° and was significantly greater in females (3.58° ± 1.49) compared with males (1.38° ± 1.00). Dividing the participants into high-motion (3.87° ± 1.19) and low-motion (1.13° ± 0.62) groups based on the mean ROM (2.39°) showed no significant differences in any measurements. Additionally, bone defects around the SIJ were identified using computed tomography of the high-motion group. In the low-motion group, calcification between auricular surfaces and bone bridges was observed. Conclusion This suggests that the SIJ ROM is influenced more by the anatomical structures around the SIJ than by the morphological characteristics of the auricular surface.

Background and Objectives: The interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block has been widely used in perioperative settings to control posterior knee pain and can additionally be used for chronic knee pain. In this cadaveric study, we aimed to investigate the needle tip position and its proximity to the articular branch of the tibial nerve (ABTN) during an iPACK-targeted radiofrequency procedure. Materials and Methods: An ultrasound-guided iPACK block was performed on 20 knees of 10 cadavers. We injected 0.1 mL each of blue and green gelatinous dye near the tibial artery (point A) and posterior knee capsule (point B), respectively, and evaluated the spread of both around the ABTN. For a hypothetical conventional radiofrequency ablation (RFA) lesion (diameter, 2.95 mm) and cooled RFA lesion (diameter, 4.9 mm), we counted the number of specimens in which the ABTNs would be captured. Results: The percentage of specimens in which the ABTN would be captured by a cooled RFA lesion was 64.71% at point A and 43.75% at point B (p = 0.334). Meanwhile, the percentage of specimens in which the ABTN would be captured by a conventional RFA lesion was 58.82% from point A and 25% from point B (p = 0.065). Conclusions: When performing an RFA-based iPACK block, the needle tip may be positioned either lateral to the tibial artery or in the space between the posterior knee capsule and the tibial artery. However, more studies with larger samples are needed to verify these results before the clinical use of this procedure can be recommended.

Jiyoung Kim, Ji Yeong Kim, Hwa Yong Shin, Sung Eun Sim, Siwook Chung, Youngjae Jeon, Sang Hyun Kim, Jong Min Jeong, Jieun Kim, U-Young Lee, and Hue Jung Park. Korean J Pain -0001;0:. https://doi.org/10.3344/kjp.23112