A comparative study of volar locking-plate fixation with corticocancellous and pure cancellous bone grafts for scaphoid nonunion with dorsal intercalated segmental instability secondary to scaphoid humpback deformity.

INTRODUCTION: Bone grafts for scaphoid nonunion with deformity include cortcicocancellous or pure cancellous bone grafts. This study compared the outcomes between two types of bone grafts when employing a volar locking-plate in patients with scaphoid nonunion with dorsal intercalated segmental instability (DISI). PATIENTS AND METHODS: This retrospective study included 34 patients with scaphoid nonunion and DISI due to humpback deformity treated between March 2017 and January 2022. Two types of bone grafts were obtained from iliac crest. Twenty of the corticocancellous (CC) group underwent a wedge-shaped graft, while 14 patients of the pure cancellous (C-only) group received graft chips. In both groups, a 1.5-mm anatomically pre-contoured locking plate was used for fixation. Radiographic evaluations included the union rate and carpal alignment including scapholunate angle (SLA), radiolunate angle (RLA), intrascaphoid angle (ISA) and scaphoid height to length ratio (HLR). Clinical assessments encompassed wrist range-of-motion, grip strength, and patient-reported outcomes. RESULTS: Nineteen of the 20 patients in the CC group and 12 of the 14 patients in the C-only group respectively, achieving osseous union. The mean follow-up period in CC group was 14.7 (range, 12 ∼ 24) months and that in C-only group was 12.6 (range, 12 ∼ 15) months. Postoperatively, there were no significant intergroup differences of radiographic parameters including SLA (CC; 49.9° ± 6.7° vs. C-only; 48.9° ± 3.5°, P = 0.676), RLA (1.7° ± 6.4° vs. 2.4° ± 3.3°, P = 0.74), ISA (36° ± 7.5° vs. 36.6° ± 12.2°, P = 0.881), and HLR (0.54 ± 0.09 vs. 0.53 ± 0.05, P = 0.587). Clinical outcomes, including the flexion-extension arc (137° ± 30° vs. 158° ± 33°, P = 0.122), grip strength (93.4 % ± 15.4% vs. 99.5 % ± 16.7 %, P = 0.39), Quick Disabilities of the Arm, Shoulder, and Hand scores (11.2 ± 8.3 vs. 12.5 ± 7.7, P = 0.74) and Mayo Wrist Scores (81.2 ± 13.1 vs. 89 ± 11.4, P = 0.242) also showed no significant intergroup differences. CONCLUSIONS: Volar locking-plate fixation with pure cancellous bone grafts achieved outcomes comparable to those achieved with corticocancellous bone grafts in scaphoid nonunion with deformity, possibly due to the biomechanical advantages of the volar plate to provide structural supports.

Sticky and Strain-Gradient Artificial Epineurium for Sutureless Nerve Repair in Rodents and Nonhuman Primates.

The need for the development of soft materials capable of stably adhering to nerve tissues without any suturing followed by additional damages is at the fore at a time when success in postoperative recovery depends largely on the surgical experience and/or specialized microsuturing skills of the surgeon. Despite fully recognizing such prerequisite conditions, designing the materials with robust adhesion to wet nerves as well as acute/chronic anti-inflammation remains to be resolved. Herein, a sticky and strain-gradient artificial epineurium (SSGAE) that overcomes the most critically challenging aspect for realizing sutureless repair of severely injured nerves is presented. In this regard, the SSGAE with a skin-inspired hierarchical structure entailing strain-gradient layers, anisotropic Janus layers including hydrophobic top and hydrophilic bottom surfaces, and synergistic self-healing capabilities enables immediate and stable neurorrhaphy in both rodent and nonhuman primate models, indicating that the bioinspired materials strategy significantly contributes to translational medicine for effective peripheral nerve repair.

Infection-related Hospitalizations During Immune Checkpoint Inhibitor Treatment Without Immunosuppressants.

Immunosuppressants are increasingly being used in the clinic to manage immune-related adverse effects. Consequently, the incidence of secondary infections associated with immunosuppression is increasing. However, little is known about primary infections during immune checkpoint inhibitor (ICI) treatment without immunosuppressants. We aimed to evaluate primary infectious diseases during antiprogrammed death ligand-1 immunotherapy without immunosuppressants. We retrospectively screened medical records of 233 patients who underwent ICI treatment for advanced non-small cell lung cancer between January 2014 and May 2018 at National Cancer Center, Republic of Korea. Subsequently, we evaluated the clinical characteristics and treatment outcomes of selected patients hospitalized for potential infectious disease without immunosuppressive treatment (n=80). Eight cases (3.4%) were identified as bacterial pneumonia (n=5) and cellulitis, inflamed epidermoid cyst, and wound infection (n=1 each). The bacterial pathogens Streptococcus pneumoniae and Haemophilus influenzae were identified in 4 patients with pneumonia. The period between the start of ICI treatment and infection varied between 3 and 189 days (median, 24.5 days). Five (62.5%) patients were infected within a month after ICI treatment initiation. All patients were treated with empirical antibiotics and discharged without complications. The median progression-free and overall survival for ICI treatment was 11.5 and 25.5 months, respectively. Six patients experienced ICI-associated adverse effects postinfection: Herpes zoster infection (n=4) and pneumonitis (n=2). Infectious disease independent of immunosuppression is a rare, but possible event in patients with lung cancer receiving ICI treatment. Clinical awareness would enable prompt diagnosis of primary infection during immunotherapy.

Whole Blood Titanium Concentration after Limb Salvage Surgery with Three-Dimensional-Printed Ti6Al4V Implants.

Background: Three-dimensional (3D)-printed customized implants can be fabricated and utilized for all bones with massive bone defects. The main safety issues with 3D-printed implants made of Ti6Al4V alloy are related to the release of metal debris and residual powder. In this study, we investigated the perioperative titanium concentrations in whole blood and peri-implant fluid samples of patients who underwent limb salvage surgery with a 3D-printed Ti6Al4V implant. Methods: Nineteen patients who underwent limb salvage surgery with 3D-printed Ti6Al4V implants were divided into two groups: the serial samples group and the follow-up group. To observe metal distribution and clearance in the body, serial samples of blood and peri-implant fluid from the surgical drain were prospectively collected for five patients in the serial samples group. For the remaining 14 patients who were followed up for more than a year, blood samples were collected only once. Results: In the serial samples group, the mean baseline titanium concentration was 0.78 µg/L (range, 0.1-2.2 µg/L): 3 patients showed peak concentration before the third postoperative month, while 2 patients still showed an increasing pattern at this point. Total titanium mass in the surgical drain showed a wash-out phenomenon in a week, with a significant uniform decrease (p = 0.04). In 14 patients in the follow-up group, the mean titanium concentration in the whole blood was 10.8 µg/L (range, 0.3-36.6 µg/L). For the 14 patients with a long-term follow-up, the aluminum and vanadium concentrations were all negligible. Conclusions: Whole blood titanium concentrations were higher after surgery using 3D-printed implants than after that using conventional orthopedic implants, but markedly lower than in patients with implant failure. None of the patients developed serious clinical adverse effects during follow-up.

Dual-light emitting 3D encryption with printable fluorescent-phosphorescent metal-organic frameworks.

Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest. Herein, we present three-dimensional (3D) printable dual-light-emitting materials for high-performance optical pattern encryption. These are based on fluorescent perovskite nanocrystals (NCs) embedded in metal-organic frameworks (MOFs) designed for phosphorescent host-guest interactions. Notably, perovskite-containing MOFs emit a highly efficient blue phosphorescence, and perovskite NCs embedded in the MOFs emit characteristic green or red fluorescence under ultraviolet (UV) irradiation. Such dual-light-emitting MOFs with independent fluorescence and phosphorescence emissions are employed in pochoir pattern encryption, wherein actual information with transient phosphorescence is efficiently concealed behind fake information with fluorescence under UV exposure. Moreover, a 3D cubic skeleton is developed with the dual-light-emitting MOF powder dispersed in 3D-printable polymer filaments for 3D dual-pattern encryption. This article outlines a universal principle for developing MOF-based room-temperature multi-light-emitting materials and a strategy for multidimensional information encryption with enhanced capacity and security.

Venous congestion affects neuromuscular changes in pigs in terms of muscle electrical activity and muscle stiffness.

Early detection of venous congestion (VC)-related diseases such as deep vein thrombosis (DVT) is important to prevent irreversible or serious pathological conditions. However, the current way of diagnosing DVT is only possible after recognizing advanced DVT symptoms such as swelling, pain, and tightness in affected extremities, which may be due to the lack of information on neuromechanical changes following VC. Thus, the goal of this study was to investigate acute neuromechanical changes in muscle electrical activity and muscle stiffness when VC was induced. The eight pigs were selected and the change of muscle stiffness from the acceleration and muscle activity in terms of integral electromyography (IEMG) was investigated in three VC stages. Consequently, we discovered a significant increase in the change in muscle stiffness and IEMG from the baseline to the VC stages (p < 0.05). Our results and approach can enable early detection of pathological conditions associated with VC, which can be a basis for further developing early diagnostic tools for detecting VC-related diseases.

Effects of Statin Treatment on the Development of Tendinopathy: A Nationwide Population-Based Cohort Study.

Background: Previous longitudinal cohort studies have reported the conflicting results of the relationship between statin use and the development of tendinopathy disorder. It is unclear if there is a relationship between statin use, particularly the type or cumulative doses, and the development of tendinopathy disorder. Purpose: To investigate an association between statin treatment and the development of tendinopathy. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 594,130 participants were enrolled in this study in 2002 and evaluated until 2015. There were 84,102 statin users and 168,204 nonusers (controls) selected at a ratio of 1:2 using propensity score matching analysis. The types of included tendinopathy were as follows: (1) trigger finger, (2) radial styloid tenosynovitis, (3) elbow epicondylitis, (4) rotator cuff tendinopathy, and (5) Achilles tendinitis. Cox proportional hazards models with time-varying covariates were constructed to identify the association between statin use and tendinopathy development. Results: Statin treatments regardless of statin types were associated with a significantly greater risk of all types of tendinopathy development (hazard ratio, 1.435; 95% CI, 1.411-1.460) compared with no statin treatment. A trend toward risk reduction was observed according to cumulative statin doses, which was indicated by hazard ratios of 2.337 (95% CI, 2.269-2.406), 2.210 (95% CI, 2.132-2.290), and 1.1 (95% CI, 1.098-1.146) in patients with cumulative defined daily doses of 90, 91-180, and >180, respectively. Conclusion: This nationwide population-based cohort study suggests that statin use regardless of the statin type was associated with a greater risk of tendinopathy compared with that of nonusers. The risk of tendinopathy development was diluted with the increasing cumulative defined daily dose.

Tendon Stress Estimation from Strain Data of a Bridge Girder Using Machine Learning-Based Surrogate Model.

Prestressed girders reduce cracking and allow for long spans, but their construction requires complex equipment and strict quality control. Their accurate design depends on a precise knowledge of tensioning force and stresses, as well as monitoring the tendon force to prevent excessive creep. Estimating tendon stress is challenging due to limited access to prestressing tendons. This study utilizes a strain-based machine learning method to estimate real-time applied tendon stress. A dataset was generated using finite element method (FEM) analysis, varying the tendon stress in a 45 m girder. Network models were trained and tested on various tendon force scenarios, with prediction errors of less than 10%. The model with the lowest RMSE was chosen for stress prediction, accurately estimating the tendon stress, and providing real-time tensioning force adjustment. The research offers insights into optimizing girder locations and strain numbers. The results demonstrate the feasibility of using machine learning with strain data for instant tendon force estimation.

Hybrid solid mesh structure for electron beam melting customized implant to treat bone cancer.

15Bone replacement implants manufactured by electron beam melting have been widely studied for use in bone tumor treatment. In this application, a hybrid structure implant with a combination of solid and lattice structures guarantees strong adhesion between bone and soft tissues. This hybrid implant must exhibit adequate mechanical performance so as to satisfy the safety criteria considering repeated weight loading during the patient's lifetime. With a low volume of a clinical case, various shape and volume combinations, including both solid and lattice structures, should be evaluated to provide guidelines for implant design. This study examined the mechanical performance of the hybrid lattice by investigating two shapes of the hybrid implant and volume fractions of the solid and lattice structures, along with microstructural, mechanical, and computational analyses. These results demonstrate how hybrid implants may be designed to improve clinical outcomes by using patient-specific orthopedic implants with optimized volume fraction of the lattice structure, allowing for effective enhancement of mechanical performance as well as optimized design for bone cell ingrowth.

Does the Clinical Presentation of Secondary Osteosarcoma in Patients Who Survive Retinoblastoma Differ From That of Conventional Osteosarcoma and How Do We Detect Them?

BACKGROUND: Osteosarcoma is the most common secondary malignancy among survivors of retinoblastoma. Most previous reports on secondary malignancy of retinoblastoma included all types of secondary malignancies without a focus on osteosarcoma, owing to its rarity. In addition, there are few studies suggesting tools for regular surveillance for early detection. QUESTIONS/PURPOSES: (1) What are the radiologic and clinical characteristics of secondary osteosarcoma after retinoblastoma? (2) What is the clinical survivorship? (3) Is a radionuclide bone scan a reasonable imaging modality for early detection in patients with retinoblastoma? METHODS: Between February 2000 and December 2019, we treated 540 patients for retinoblastoma. Twelve patients (six male, six female) subsequently developed an osteosarcoma in the extremities; two of these patients had two sites of osteosarcoma (10 femurs, four tibiae) . A Technetium-99m bone scan image was examined annually in all patients for regular surveillance after the treatment of retinoblastoma as per our hospital's policy. All patients were treated with the same strategy as that used for primary conventional osteosarcoma, namely neoadjuvant chemotherapy, wide excision, and adjuvant chemotherapy. The median follow-up period was 12 years (range 8 to 21 years). The median age at the time of diagnosis of osteosarcoma was 9 years (range 5 to 15 years), and the median interval from retinoblastoma diagnosis to osteosarcoma diagnosis was 8 years (range 5 to 15 years). Radiologic characteristics were assessed with plain radiographs and MRI, while clinical characteristics were assessed through a retrospective review of medical records. For clinical survivorship, we evaluated overall survival, local recurrence-free survival, and metastasis-free survival. We reviewed the results of bone scans and clinical symptoms at the time of diagnosis for osteosarcoma after retinoblastoma. RESULTS: In nine of 14 patients, the tumor had a diaphyseal center, and five of the tumors were located at the metaphysis. The femur was the most common site (n = 10), followed by the tibia (n = 4). The median tumor size was 9 cm (range 5 to 13 cm). There was no local recurrence after surgical resection of the osteosarcoma, and the 5-year overall survival rate after the diagnosis of osteosarcoma was 86% (95% CI 68% to 100%). In all 14 tumors, the Technetium bone scan showed increased uptake in the lesions. Ten of 14 tumors were examined in clinic because of patient complaints of pain in the affected limb. Four patients showed no clinical symptoms detected by abnormal uptake on bone scan. CONCLUSION: For unclear reasons, secondary osteosarcomas in patients who were alive after the treatment of retinoblastoma had a slight predilection for the diaphysis of the long bone compared with patients with spontaneous osteosarcoma in other reports. The clinical survivorship of osteosarcoma as a secondary malignancy after retinoblastoma may not be inferior to that of conventional osteosarcoma. Close follow-up with at least yearly clinical assessment and bone scans or other imaging modalities appears to be helpful in detecting secondary osteosarcoma after the treatment of patients with retinoblastoma. Larger multi-institutional studies will be needed to substantiate these observations.Level of Evidenc e Level IV, therapeutic study.

Surgical Outcomes of Percutaneous Pinning and Open Locking Plating in Patients With Intra-articular Fractures of the Base of the Fifth Metacarpal.

PURPOSE: The purpose of the study was to demonstrate the results of surgical treatment, including percutaneous K-wire fixation after closed reduction (CRKF) or locking plate fixation after open reduction (ORPF), in patients with intra-articular fractures of the base of the fifth metacarpal. METHODS: We retrospectively reviewed data of 29 patients who received surgical treatment for closed, intra-articular fractures of the base of the fifth metacarpal and were followed up for at least 1 year after surgery. Sixteen of the 29 patients underwent CRKF, whereas 13 patients underwent ORPF. Attempts were made to address intra-articular step-off with closed reduction in all the patients; however, if inadequate, ORPF was performed. Clinical outcomes were evaluated using Disabilities of the Arm, Shoulder, and Hand scores, visual analog scale pain scores, the total active motion (TAM) of the little finger, and grip strength. Osseous union and posttraumatic arthritis of the fifth carpometacarpal joint were also evaluated. RESULTS: K-wire fixation after closed reduction was performed for 13 simple fractures and 3 comminuted fractures; ORPF was performed for 6 simple fractures and 7 comminuted fractures. All the patients had satisfactory subjective outcomes with over 90% grip strength compared with that on the contralateral side and nearly full TAM. All the patients in both the groups achieved osseous union. There were five cases of grade 1 posttraumatic arthritis after CRKF and seven cases of grade 1 posttraumatic arthritis after ORPF. CONCLUSIONS: Surgical treatment provided satisfactory results in patients with intra-articular fractures of the base of the fifth metacarpal treated with either CRKF or ORPF. Our data showed that the patients who underwent CPKF had good results, and those who underwent ORPF after attempt failure of close reduction also had good results. Our experience suggests that ORPF can be a backup plan when CRKF cannot be accomplished in a satisfactory way. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Detection and Length Measurement of Cracks Captured in Low Definitions Using Convolutional Neural Networks.

Continuous efforts were made in detecting cracks in images. Varied CNN models were developed and tested for detecting or segmenting crack regions. However, most datasets used in previous works contained clearly distinctive crack images. No previous methods were validated on blurry cracks captured in low definitions. Therefore, this paper presented a framework of detecting the regions of blurred, indistinct concrete cracks. The framework divides an image into small square patches which are classified into crack or non-crack. Well-known CNN models were employed for the classification and compared with each other with experimental tests. This paper also elaborated on critical factors-the patch size and the way of labeling patches-which had considerable influences on the training performance. Furthermore, a series of post-processes for measuring crack lengths were introduced. The proposed framework was tested on the images of bridge decks containing blurred thin cracks and showed reliable performance comparable to practitioners.

Humidity-Tolerant Moisture-Driven Energy Generator with MXene Aerogel-Organohydrogel Bilayer.

Free-standing and film-type moisture-driven energy generators (MEGs) that harness the preferential interaction of ionized moisture with hydrophilic materials are interesting because of their wearability and portability without needing a water container. However, most such MEGs work in limited humidity conditions, which provide a substantial moisture gradient. Herein, we present a high-performance MEG with sustainable power-production capability in a wide range of environments. The bilayer-based device comprises a negatively surface-charged, hydrophilic MXene (Ti3C2Tx) aerogel and polyacrylamide (PAM) ionic hydrogel. The preferential selection on the MXene aerogel of positive charges supplied from the salts and water in the hydrogel is predicted by the first-principle simulation, which results in a high electric output in a wide relative humidity range from 20% to 95%. Furthermore, by replacing the hydrogel with an organohydrogel of PAM that has excellent water retention and structural stability, a device with long-term electricity generation is realized for more than 15 days in a broad temperature range (from -20 to 80 °C). Our MXene aerogel MEGs connected in series supply sufficient power for commercial electronic components in various outdoor environments. Moreover, an MXene aerogel MEG works as a self-powered sensor for recognizing finger bending and facial expression.

New established cell lines from undifferentiated pleomorphic sarcoma for in vivo study.

As a high-grade soft-tissue sarcoma (STS), undifferentiated pleomorphic sarcoma (UPS) is highly recurrent and malignant. UPS is categorized as a tumor of uncertain differentiation and has few options for treatment due to its lack of targetable genetic alterations. There are also few cell lines that provide a representative model for UPS, leading to a dearth of experimental research. Here, we established and characterized new cell lines derived from two recurrent UPS tissues. Cells were obtained from UPS tissues by mincing, followed by extraction or dissociation using enzymes and culture in a standard culture environment. Cells were maintained for several months without artificial treatment, and some cell clones were found to be tumorigenic in an immunodeficient mouse model. Interestingly, some cells formed tumors in vivo when injected after aggregation in a non-adherent culture system for 24 h. The tissues from in vivo study and tissues from patients shared common histological characteristics. Pathways related to the cell cycle, such as DNA replication, were enriched in both cell clones. Pathways related to cell-cell adhesion and cell-cell signaling were also enriched, suggesting a role of the mesenchymal-to-epithelial transition for tumorigenicity in vivo. These new UPS cell lines may facilitate research to identify therapeutic strategies for UPS. [BMB Reports 2023; 56(4): 258-264].

Classification of deep vein thrombosis stages using convolutional neural network of electromyogram with vibrotactile stimulation toward developing an early diagnostic tool: A preliminary study on a pig model.

Deep vein thrombosis (DVT) can lead to life-threatening disorders; however, it can only be recognized after its symptom appear. This study proposed a novel method that can detect the early stage of DVT using electromyography (EMG) signals with vibration stimuli using the convolutional neural networks (CNN) algorithm. The feasibility of the method was tested with eight legs before and after the surgical induction of DVT at nine-time points. Furthermore, perfusion pressure (PP), intracompartmental pressure (IP), and shear elastic modulus (SEM) of the tibialis anterior were also collected. In the proposed method, principal component analysis (PCA) and CNN were used to analyze the EMG data and classify it before and after the DVT stages. The cross-validation was performed in two strategies. One is for each leg and the other is the leave-one-leg-out (LOLO), test without any predicted information, for considering the practical diagnostic tool. The results showed that PCA-CNN can classify before and after DVT stages with an average accuracy of 100% (each leg) and 68.4±20.5% (LOLO). Moreover, all-time points (before induction of DVT and eight-time points after DVT) were classified with an average accuracy of 72.0±11.9% which is substantially higher accuracy than the chance levels (11% for 9-class classification). Based on the experimental results in the pig model, the proposed CNN-based method can classify the before- and after-DVT stages with high accuracy. The experimental results can provide a basis for further developing an early diagnostic tool for DVT using only EMG signals with vibration stimuli.

Ulnar positive variance associated with TFCC foveal tear.

OBJECTIVE: The ulnar positive variance (UPV) can be observed on simple radiography due to a triangular fibrocartilage complex (TFCC) foveal tear. This study investigated to identify how much radiographic UPV occurs due to a TFCC foveal tear, which may be misdiagnosed as an ulnar impaction syndrome (UIS). MATERIALS AND METHODS: One hundred forty patients who underwent arthroscopic transosseus TFCC foveal repair from March 2013 to March 2019 in our institution were enrolled in this study. Ulnar variances were measured in preoperative, postoperative 6 weeks, 1-year follow-up wrist posteroanterior (PA) radiograph, and power grip PA radiograph of the affected wrist and were compared with those of the same patient's unaffected wrist. RESULTS: In the neutral wrist PA radiograph, ulnar variance increased by 0.56 mm (p < 0.001) after TFCC foveal tear compared to the unaffected side. In the power grip view, ulnar variance also increased by 0.39 mm (p < 0.001) in the affected wrist. The preoperative ulnar positive variance was reduced after an arthroscopic transosseous TFCC foveal repair from 0.56 to 0 mm (p < 0.001). No significant statistical difference was observed between an Atzei class 2 and 3 TFCC tear (0.56 mm vs. 0.41 mm, p = 0.263). CONCLUSION: This study revealed that TFCC foveal tear induces 0.56 mm of radiologic UPV, which was successfully corrected after arthroscopic transosseous TFCC foveal repair. Therefore, UPV associated with TFCC foveal tear should not be misdiagnosed as an UIS. Also, when ulnar shortening osteotomy is planned in case of UIS combined with TFCC foveal tear, the amount of UPV induced by TFCC foveal tear should be considered to prevent over-shortening.

Clinical characteristics and long-term outcomes of rhabdomyosarcoma in Korean children, adolescents and young adults: a single-center experience.

PURPOSE: This study aimed to analyze characteristics, treatment, long-term outcomes, and prognostic factors for children, adolescents and young adults with rhabdomysosarcoma (RMS). METHODS: This retrospective historical study included 75 patients with RMS treated between 2002 and 2019. Clinical data and follow-up results were collected including all diagnosis, treatment and prognosis information. RESULTS: Patients median-age-at-diagnosis was 6 years. Embryonal and alveolar histology occurred in 51 (68.0%) and 21 (28.0%) patients, respectively. The tumors most frequently originated from parameningeal site (28.0%). Of 74 evaluable patients for treatment outcome, 60 (81.1%) achieved complete response for first-line treatment, of whom, 34 (56.6%) maintained complete response, 26 (43.3%; 23/26, local relapse) showed relapse. Of 40 patients with treatment failure, 16 and 6 occurred in parameningeal area and retroperitoneum/perineum, respectively. The 5-year progression-free survival (PFS) and overall survival (OS) were 45.0% and 64.5%, respectively. In multivariate analyses, parameningeal site (p = 0.027), no gross total resection (p = 0.047), and no radiation therapy (RT) (p < 0.001) for PFS; and parameningeal site (p < 0.001) and no RT (p = 0.010) for worse OS, were significant. The median PFS and OS from treatment failure date in 40 patients with primary treatment failure were 1.3 and 4.1 years, respectively. Of 26 patients with relapse, interval to relapse < 7 months, retroperitoneum/perineum site, TNM stages III/IIV, and no salvage RT were independently associated with OS. CONCLUSION: The importance of adequate local therapy was highlighted in RMS treatment. Treatment failure was largely a local failure. Whether as a component of initial or salvage treatment, RT could improve patients' survival.

Clinical Outcomes of Arthroscopic One-Tunnel Triangular Fibrocartilage Complex Transosseous Suture Repair Are Not Diminished in Cases of Ulnar Styloid Process Fracture Nonunion.

PURPOSE: To determine whether clinical outcomes of arthroscopic one-tunnel wrist triangular fibrocartilage complex (TFCC) transosseous suture repair are not diminished in cases of ulnar styloid process fracture nonunion (USPFN). METHODS: Patients who underwent arthroscopic 1-tunnel transosseous suture repair of Palmer 1B foveal TFCC tear (with/without superficial fiber tear; Atzei class 2 or 3 TFCC tear) from 2015 to 2020 were retrospectively reviewed. Group I was the TFCC foveal tear repair group with USPFN. Group II was the TFCC foveal tear repair group without USPFN. In group I, no additional treatment for USPFN was made. Functional preoperative and postoperative outcomes were compared by Modified Mayo Wrist Score (MMWS); Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score; grip strength; pain visual analog scale (VAS); and distal radioulnar joint (DRUJ) stability. Wrist posteroanterior, lateral, and both oblique views of the wrist were used to assess the ulnar styloid process before and after operation. RESULTS: This study consisted of 66 patients: group I (n = 22) and group II (n = 44). No differences were found between the 2 groups preoperatively in MMWS, Quick-DASH, grip strength, and VAS (MMWS: P = .94, Quick-DASH: P = .23, grip strength: P = .69, VAS: P = .45). No differences were found between the 2 groups with respect to outcome measures postoperatively in MMWS, Quick-DASH, grip strength, and VAS (MMWS: P = .59, Quick DASH: P = .82, grip strength: P = .15, VAS: P = .84). All of the enrolled patients achieved restored function with negative ballottement test and maintained DRUJ stability on follow-up. Of the 22 USPFN cases in group I, 11 (50%) showed spontaneous union after transosseous TFCC foveal repair without any additional USPFN treatment. The proportion of patients achieving a minimal clinically important difference for the Quick-DASH was similar between the 2 groups. CONCLUSIONS: Although this current study has insufficient statistical power, the available data suggest that patients with TFCC foveal tear combined with USPFNs treated with arthroscopic transosseous repair surgery could experience similar functional improvement compared with those with TFCC foveal tear without USPFNs. The presence of USPFN accompanied by Palmer 1B type TFCC foveal tear may not affect the clinical results, including MMWS, Quick-DASH, grip strength, VAS, and DRUJ stability of patients who undergo arthroscopic 1-tunnel transosseous suture repair. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Risk Factors of Flexor Tendon Rupture After ORIF of Distal Radius Fracture.

OBJECTIVES: To analyze the risk factors associated with postoperative flexor tendon rupture, after a volar plate fixation of distal radius fractures. DESIGN: Retrospective observational case-control study. SETTING: Tertiary Care University Hospital in the Republic of Korea (2009-2020). PATIENTS: Sixteen referred patients were treated for flexor tendon rupture, following previously performed volar plating of distal radius fractures at other institutions. 16 patients were randomly selected from our database as controls, and were matched based on the Soong grade of the case group. INTERVENTION: Not applicable. MAIN OUTCOME MEASUREMENTS: Radial tilt and radial height were measured on anteroposterior radiographs. The volar tilt, tear drop angle, carpal translation, and Soong grade were measured in a lateral view. RESULTS: Quantitative measurements of the volar tilt, carpal translation, and tear drop angle were positively correlated with the flexor tendon rupture. The mean volar tilt and tear drop angle in the tendon rupture group were significantly smaller than those in the control group. The mean carpal translation in the tendon rupture group was significantly greater than that in the control group. CONCLUSIONS: This study demonstrated that volar tilt, carpal translation, and tear drop angle are significant risk factors for flexor tendon rupture, especially for plates placed at Soong grade 1 or 2. We suggest that the potential for tendon rupture because of incomplete reduction of the distal radius fracture along with implant prominence volar to the watershed line aggravates flexor tendon irritation at the distal edge of the plate because of distorted flexor tendon paths. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of Intraosseous Pressure during Pelvic Percutaneous Cement Injection: An In Vitro Study in Swine.

Background: A minimally invasive procedure for symptomatic pelvic bone metastasis is a feasible option for advanced cancer patients, and bone cement injection plays an essential role. Pulmonary embolism caused by thrombus, fat, or tumor emboli is a major complication related to bone cement injection, and increasing intraosseous pressure is a predisposing factor. This study aimed to quantify the degree of pressure change in the pelvic bone during percutaneous bone cement injection and investigate whether there is a significant decrease in intraosseous pressure when a decompressive route is additionally established. Methods: Bone cement injection into the acetabulum of swine pelvises by simulating the actual surgical procedure in terms of the injection method, bone cement, and surgical instruments was performed while recording the intraosseous pressure. Twenty swine pelvises were used and grouped into a decompression group and a non-decompression group. Bone cement injection and pressure measurement were conducted in the same way in both groups, but an additional decompressive route was established for each pelvis in the decompression group. Continuous variables were compared using the Mann-Whitney test. Results: The mean amount of injected bone cement was 19.8 mL and 20.3 mL and the mean speed of bone cement injection was 0.14 mL/sec and 0.12 mL/sec in the decompression group and the non-decompression group, respectively. The mean peak intraosseous pressures was 10.5 kPa with decompression and 37.8 kPa without decompression, and the difference was statistically significant (p < 0.01). Conclusions: Intraosseous pressure during bone cement injection into swine pelvises was similar to that during vertebroplasty or kyphoplasty. When the additional decompression route was established, the intraosseous pressure decreased to one third the level.