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.

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 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.

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.

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.

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.

Percutaneous Cementoplasty for the Pelvis in Bone Metastasis: 12-Year Experience.

BACKGROUND: In advanced cancer patients, pelvic bone metastasis often causes pain and gait disturbance. The use of percutaneous bone cement [polymethylmethacrylate (PMMA)] injection for pain management and strengthening in pelvic bone metastasis has rarely been reported. To evaluate this method, we aimed to determine surgical outcomes and complications over a long-term follow-up period using a large patient group. PATIENTS AND METHODS: We retrospectively collected data from 178 patients who underwent percutaneous cementoplasty for pelvic metastatic lesions, 201 in total. Surgical outcomes evaluated included pain reduction and improvement of ambulation. Mortality within 1 month after procedure and pulmonary embolism caused by thrombus, fat, tumor emboli, or bone cement were investigated as surgical complications. For long-term survivors, pain relapse and mechanical failure were analyzed. The mean follow-up period was 12.6 months, and there were 159 fatalities at last follow-up. RESULTS: The mean regional pain numerical rating scale scores decreased from 6.1 preoperatively to 2.4 1 month after procedure (p < 0.01). Gait function was maintained, worsened, and uncheckable in 68%, 24%, and 8% of patients, respectively, 1 month after procedure. Of long-term survivors followed up for > 12 months (n = 53), there were no significant changes in serial plain radiographs, and regional pain aggravation was observed in 9%. Pulmonary cement embolism and bone cement implantation syndrome was observed in 11% and 10%, respectively. However, all patients with these complications were asymptomatic. CONCLUSIONS: Percutaneous cement injection into the pelvis is a feasible and safe palliative surgical option for patients with advanced malignancy in terms of pain reduction and maintenance of ambulatory function under regional anesthesia.

Editorial Commentary: Arthroscopic Capsular Repair of Wrist Triangular Fibrocartilage Complex Tears: Beware That Apparent Isolated Atzei Class 1 (Isolated Distal Component) Tears May Include a Proximal Component.

Accumulating knowledge about the anatomy of the triangular fibrocartilage complex (TFCC) and its function has revealed that the foveal insertion of the TFCC plays a key role in distal radioulnar joint stability rather than the superficial fibers that insert into the ulnar styloid. Recently, the interest in torn peripheral TFCC repair has been shifting from capsular repair for Atzei class 1 to foveal repair for Atzei class 2 or 3. Most acute Atzei class 1 tears spontaneously heal without surgical repair; in contrast, in cases of sustained pain and distal radioulnar joint instability even after successful Atzei class 1 repair, the unrecognized proximal component TFCC tear concomitant with a distal component TFCC tear may exist and appropriate treatment for the proximal component TFCC tear should be combined. Although overall successful results have been reported using various repair techniques, the most important consideration is re-establishing biologic regeneration potential at the insertion site of torn TFCC.

Revisional triangular fibrocartilage complex (TFCC) repair using arthroscopic one-tunnel transosseous suture: preliminary results.

PURPOSE: The purpose of this study was to report the clinical outcome of revision arthroscopic triangular fibrocartilage complex (TFCC) foveal repair using a one-tunnel transosseous suture technique after failed primary TFCC repair. METHODS: Consecutive patients treated with arthroscopic TFCC foveal repair using the uniform one-tunnel transosseous suture technique after failed TFCC repair from 2014 to 2018 were retrospectively reviewed. The clinical outcome was evaluated using the Modified Mayo Wrist Score (MMWS) and the Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score. The Visual Analog Scale (VAS) for pain, stability of the distal radioulnar joint (DRUJ), grip strength, and active range of motion (ROM) of the wrist joint also were assessed. RESULTS: This study cohort consisted of eight patients, and their mean time to revision after initial surgery was 15.1 months. Previous surgeries were performed using an arthroscopy-assisted mini-open TFCC repair in six cases, an arthroscopic all-inside repair in one case, and an arthroscopic transosseous suture technique in the remaining case. After revisional TFCC foveal repair, all patients demonstrated improved pain and a stable DRUJ. Participants showed improvement in grip strength and mean active wrist ROM. There was improvement in MMWS (from 58.6 to 87.5) and Quick-DASH score (from 46.9 to 12.2) during the mean follow-up of 15.6 months (range: 8-36 months). CONCLUSION: Based on the results of this study, remaining ulnar TFCC remnants may be appropriate for sufficient stable repair using an arthroscopic one-tunnel transosseous suture technique after failed primary repair. However, only a small number of patients was examined. A larger number has to be investigated to confirm the promising preliminary results. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Influence of TFCC foveal tear on the location of lunate chondromalacia in ulnar impaction syndrome.

OBJECTIVE: The purpose of this study was to identify the location of lunate chondromalacia and to compare the difference in location according to presence or absence of triangular fibrocartilage complex (TFCC) foveal tear, which induces distal radioulnar joint (DRUJ) instability. METHODS: We performed a retrospective study of 97 patients (102 wrists) who were diagnosed with and treated for idiopathic ulnar impaction syndrome (UIS) between 2014 and 2018. Subjects were divided into two groups according to presence or absence of TFCC foveal tear with DRUJ instability. Group I had UIS without a TFCC foveal tear (52 wrists, mean age of 43.2 years), while Group II had UIS with a TFCC foveal tear (50 wrists, mean age of 45.3 years). There was no significant difference in age, sex, or duration of symptoms between the two groups. All patients underwent wrist MR Arthrography (MRA) in the same gantry, and all scanned coronal sections of the lunate were standardized into 10 slices, including the whole anteroposterior width of the lunate. Each slice was sequentially numbered from dorsal to volar side, and the location of chondromalacia was marked in each numbered section. Radiological parameters including ulnar variance and ulnolunate distance (ULD), which indicated the distance between the ulnar head and lunate, were measured in the wrist series. RESULTS: The most frequent location of lunate chondromalacia was slightly to the volar side of the lunate in both groups. Group I showed a higher frequency of chondromalacia in the volar side of the lunate. In Group II, chondromalacia was identified with high frequency not only on the volar side of the lunate but also on the dorsal side. In other words, Group II showed broader chondromalacia in the lunate. There was no significant difference in ulnar variance (Group I, 3.19 ± 1.42 mm; Group II, 2.76 mm ± 1.67 mm) or ulnolunate distance (Group I, 1.66 ± 0.94 mm; Group II, 2.05 mm ± 0.87 mm). The average ULD decreased during radial deviation but increased during ulnar deviation. CONCLUSION: This study showed that lunate chondromalacia associated with idiopathic ulnar impaction syndrome occurs more frequently on the volar side of the lunate. Also, TFCC foveal tear, which causes DRUJ instability, leads to broader lunate chondromalacia in idiopathic ulnar impaction syndrome. Therefore, further analysis of the pattern of lunate chondromalacia can provide a clue for DRUJ instability.

Comparison between normal and reverse orientation of graft in functional and histomorphological outcomes after autologous nerve grafting: An experimental study in the mouse model.

BACKGROUND: Autologous nerve grafting has been considered the gold standard for the treatment of irreparable nerve gaps. However, the choice of effective proximodistal orientation of autografts (normal or reversed) is controversial. Therefore, we compared functional and histological outcomes between normal and reversed orientations of autografts in a mouse sciatic nerve model. MATERIALS AND METHODS: Thirty C57BL/6J mice weighing 20-25 g were assigned to the donor, normally oriented autograft, and reverse-oriented autograft groups (n = 10 per group). A 10-mm section of the sciatic nerve was harvested from a donor mouse. Half the harvested nerve was grafted onto an irreparable gap in a recipient mouse using either a normal or reversed orientation. The sciatic functional index (SFI) was measured biweekly for up to 12 weeks postoperatively. Morphological analysis was performed using immunofluorescence staining for neurofilament (NF) and myelin protein zero (P0) in cross-sectional and whole-mount nerve preparations in 12 weeks postoperatively. Additionally, morphological analysis of the tibialis anterior muscle was performed using hematoxylin and eosin staining. NF or P0-expressing axons were counted and cross-sectional area (CSA) and minimum Feret's diameter of myofibers were measured. RESULTS: The SFI recovered gradually up to 12 weeks after autografting, but there were no significant differences in the SFI between the normal and reversed orientations. The number of NF-expressing axons in center of graft was significantly higher in the normal orientation than in the reversed orientation (P < .05). However, there were no significant differences in the number and mean intensity of P0-expressing axons between the orientations. The CSA of myofibers was significantly larger in the normal orientation than in the reversed orientation (P < .05). CONCLUSIONS: Normally oriented autografts promote axonal regrowth and prevent neurogenic muscular atrophy compared with reverse-oriented autografts. However, despite these positive histomorphometric effects, the proximodistal orientation of the autograft does not affect functional outcomes.

Development of a Reference-Free Indirect Bridge Displacement Sensing System.

Bridge displacement measurements are important data for assessing the condition of a bridge. Measuring bridge displacement under moving vehicle loads is helpful for rating the load-carrying capacity and evaluating the structural health of a bridge. Displacements are conventionally measured using a linear variable differential transformer (LVDT), which needs stable reference points and thus prohibits the use of this method for measuring displacements for bridges crossing sea channels, large rivers, and highways. This paper proposes a reference-free indirect bridge displacement sensing system using a multichannel sensor board strain and accelerometer with a commercial wireless sensor platform (Xnode). The indirect displacement estimation method is then optimized for measuring the structural displacement. The performance of the developed system was experimentally evaluated on concrete- and steelbox girder bridges. In comparison with the reference LVDT data, the maximum displacement error for the proposed method was 2.17%. The proposed method was successfully applied to the displacement monitoring of a tall bridge (height = 20 m), which was very difficult to monitor using existing systems.

Prediction of Lower Extremity Multi-Joint Angles during Overground Walking by Using a Single IMU with a Low Frequency Based on an LSTM Recurrent Neural Network.

The joint angle during gait is an important indicator, such as injury risk index, rehabilitation status evaluation, etc. To analyze gait, inertial measurement unit (IMU) sensors have been used in studies and continuously developed; however, they are difficult to utilize in daily life because of the inconvenience of having to attach multiple sensors together and the difficulty of long-term use due to the battery consumption required for high data sampling rates. To overcome these problems, this study propose a multi-joint angle estimation method based on a long short-term memory (LSTM) recurrent neural network with a single low-frequency (23 Hz) IMU sensor. IMU sensor data attached to the lateral shank were measured during overground walking at a self-selected speed for 30 healthy young persons. The results show a comparatively good accuracy level, similar to previous studies using high-frequency IMU sensors. Compared to the reference results obtained from the motion capture system, the estimated angle coefficient of determination (R2) is greater than 0.74, and the root mean square error and normalized root mean square error (NRMSE) are less than 7° and 9.87%, respectively. The knee joint showed the best estimation performance in terms of the NRMSE and R2 among the hip, knee, and ankle joints.

Development of Low-Cost Wireless Sensing System for Smart Ultra-High Performance Concrete.

This study proposes the development of a wireless sensor system integrated with smart ultra-high performance concrete (UHPC) for sensing and transmitting changes in stress and damage occurrence in real-time. The smart UHPC, which has the self-sensing ability, comprises steel fibers, fine steel slag aggregates (FSSAs), and multiwall carbon nanotubes (MWCNTs) as functional fillers. The proposed wireless sensing system used a low-cost microcontroller unit (MCU) and two-probe resistance sensing circuit to capture change in electrical resistance of self-sensing UHPC due to external stress. For wireless transmission, the developed wireless sensing system used Bluetooth low energy (BLE) beacon for low-power and multi-channel data transmission. For experimental validation of the proposed smart UHPC, two types of specimens for tensile and compression tests were fabricated. In the laboratory test, using a universal testing machine, the change in electrical resistivity was measured and compared with a reference DC resistance meter. The proposed wireless sensing system showed decreased electrical resistance under compressive and tensile load. The fractional change in resistivity (FCR) was monitored at 39.2% under the maximum compressive stress and 12.35% per crack under the maximum compressive stress tension. The electrical resistance changes in both compression and tension showed similar behavior, measured by a DC meter and validated the developed integration of wireless sensing system and smart UHPC.

SSVM: An Ultra-Low-Power Strain Sensing and Visualization Module for Long-Term Structural Health Monitoring.

Structural health monitoring (SHM) is crucial for quantitative behavioral analysis of structural members such as fatigue, buckling, and crack propagation identification. However, formerly developed approaches cannot be implemented effectively for long-term infrastructure monitoring, owing to power inefficiency and data management challenges. This study presents the development of a high-fidelity and ultra-low-power strain sensing and visualization module (SSVM), along with an effective data management technique. Deployment of 24-bit resolution analog to a digital converter and precise half-bridge circuit for strain sensing are two significant factors for efficient strain measurement and power management circuit incorporating a low-power microcontroller unit (MCU), and electronic-paper display (EPD) enabled long-term operation. A prototype for SSVM was developed that performs strain sensing and encodes the strain response in a QR code for visualization on the EPD. For efficient power management, SSVM only activated when the trigger-signal was generated and stayed in power-saving mode consuming 18 mA and 337.9 µA, respectively. The trigger-signal was designed to be generated either periodically by a timer or intentionally by a push-button. A smartphone application and cloud database were developed for efficient data acquisition and management. A lab-scale experiment was carried out to validate the proposed system with a reference strain sensing system. A cantilever beam was deflected by increasing load at its free end, and the resultant strain response of SSVM was compared with the reference. The proposed system was successfully validated to use for long-term static strain measurement.

The application of 3D-printing technology in pelvic bone tumor surgery.

BACKGROUND: Three-dimensional (3D)-printing technology provides an advanced approach to pelvic bone tumor resection and reconstruction. However, only a few cases of pelvic bone tumor surgery using 3D-printing have been reported due to limited time since the introduction of the new implant. This study introduces pelvic bone tumor surgeries using 3D-printed bone-cutting guides and implants. METHODS: This single-center retrospective review included 12 patients who underwent malignant pelvic bone tumor surgeries using a 3D-printed bone-cutting guide and/or implant. Clinical information was collected regarding patient demographics, tumor characteristics, pathologic diagnosis, surgery details, and functional recovery. RESULTS: Type I internal hemipelvectomy was performed using 3D-printed bone-cutting guides for 4 patients that underwent cavitary bone tumor resection of the ilium. For 3 of these 4 patients, cavitary bone defects were filled with structural allobone graft precisely trimmed by the 3D-printed allograft-shaping guide (n = 1) and 3D-printed mesh-style titanium spacer (n = 2). For type II and III areas, one and two patients, respectively, underwent 3D-printing-assisted surgery. Five patients underwent type I, II, and III pelvic resection using 3D-printed cutting guides and reconstruction with 3D-printed implants. In all patients, independent gait was recovered except for a patient who underwent hindquarter amputation 4 months postoperatively because of local recurrence. CONCLUSIONS: This study provides preliminary, short-term data on the efficacy and safety of pelvic bone tumor surgery using 3D-printing.

Enhanced Regeneration of Vascularized Adipose Tissue with Dual 3D-Printed Elastic Polymer/dECM Hydrogel Complex.

A flexible and bioactive scaffold for adipose tissue engineering was fabricated and evaluated by dual nozzle three-dimensional printing. A highly elastic poly (L-lactide-co-ε-caprolactone) (PLCL) copolymer, which acted as the main scaffolding, and human adipose tissue derived decellularized extracellular matrix (dECM) hydrogels were used as the printing inks to form the scaffolds. To prepare the three-dimensional (3D) scaffolds, the PLCL co-polymer was printed with a hot melting extruder system while retaining its physical character, similar to adipose tissue, which is beneficial for regeneration. Moreover, to promote adipogenic differentiation and angiogenesis, adipose tissue-derived dECM was used. To optimize the printability of the hydrogel inks, a mixture of collagen type I and dECM hydrogels was used. Furthermore, we examined the adipose tissue formation and angiogenesis of the PLCL/dECM complex scaffold. From in vivo experiments, it was observed that the matured adipose-like tissue structures were abundant, and the number of matured capillaries was remarkably higher in the hydrogel-PLCL group than in the PLCL-only group. Moreover, a higher expression of M2 macrophages, which are known to be involved in the remodeling and regeneration of tissues, was detected in the hydrogel-PLCL group by immunofluorescence analysis. Based on these results, we suggest that our PLCL/dECM fabricated by a dual 3D printing system will be useful for the treatment of large volume fat tissue regeneration.

Ultrasound diagnosis and follow-up of a locked thumb metacarpophalangeal joint caused by radial sesamoid entrapment: a case report.

BACKGROUND: A locked thumb metacarpophalangeal joint is a rare condition that presents as restricted joint motions with mild hyperextension deformity, usually after a relatively minor hyperextension injury. Owing to the limitations of radiographs, computed tomography is a useful diagnostic imaging modality for assessing sesamoid displacement. However, despite its convenience, ultrasound findings of the locked thumb have rarely been reported. Here, we report a case of a locked thumb metacarpophalangeal joint diagnosed and followed-up using ultrasound. CASE PRESENTATION: A 15-year-old boy with a locked thumb metacarpophalangeal joint presented to our hospital. On physical examination, the 1st metacarpophalangeal joint was found to be hyperextended, and active and passive flexions were not possible. While radiographs were inconclusive, ultrasound revealed radial sesamoid entrapment at the 1st metacarpophalangeal joint causing locking. After closed manual reduction, metacarpophalangeal motions recovered. Success of the reduction was also confirmable by ultrasound. CONCLUSIONS: Ultrasound can be a feasible modality to diagnose a locked thumb metacarpophalangeal joint and immediately judge the success or failure of the reduction.

Changes in the morphology of the triangular fibrocartilage complex (TFCC) on magnetic resonance arthrography related to disruption of ulnar foveal attachment.

OBJECTIVE: To assess whether a proximal ligamentous component (PLC) of the triangular fibrocartilage complex (TFCC) with a distally prolapsing morphology is associated with the presence of a TFCC foveal tear on arthroscopy. METHODS: One-hundred thirty-two patients (134 wrists) who underwent MR arthrography and subsequent wrist arthroscopy between September 2014 and March 2018 were retrospectively evaluated. The degree of distal PLC prolapse was measured on coronal MR arthrography using the height-to-length ratio (HLR). Subjects' demographics, ulnar variance, presence of a degenerative TFCC tear, and ulnar styloid nonunion were assessed. The association between specific variables and the presence of a foveal tear was investigated. RESULTS: A TFCC foveal tear was identified in a total of 101 of 134 wrists examined by arthroscopy. Univariable analysis showed that the HLR of the PLC was significantly greater in the foveal tear group compared with the intact fovea group (44.6 vs. 38.9%, respectively, p < 0.001). Multivariable analysis showed that HLR was positively associated with a foveal tear (odds ratio [OR], 1.211; p < 0.001). The estimated cut-off value of the HLR was 41% (area under the curve [AUC] 0.77). CONCLUSIONS: PLCs with a distal prolapse pattern and large HLR are associated with TFCC foveal tears. The HLR of the PLC measured on coronal MR images can therefore be used as an additional predictor of tears of the foveal attachment of the TFCC.

Functional Outcomes Are Similar After Early and Late Arthroscopic One-Tunnel Transosseous Repair of Triangular Fibrocartilage Complex Foveal Tears.

PURPOSE: To compare outcomes at different time periods following arthroscopic triangular fibrocartilage complex (TFCC) transosseous foveal repair within 6 months, between 6 and 12 months, and more than 12 months from injury. METHODS: Consecutive patients treated with arthroscopic TFCC foveal repair using the uniform one-tunnel transosseous suture technique by a surgeon from 2014 to 2017 were retrospectively reviewed. The patients were assigned to 1 of 3 groups according to time between injury and surgery. Pain visual analog scale (VAS); grip strength; modified Mayo wrist score (MMWS); Quick disabilities of the arm, shoulder, and hand (QuickDASH) score; and distal radioulnar joint stability were assessed at minimum 2 years postoperatively, along with minimal clinically important difference, and overall patient satisfaction. RESULTS: This study cohort consisted of 80 patients: group A (<6 months, n = 38), group B (6-12 months, n = 20), and group C (>12 months, n = 22). No differences were found among groups in VAS, grip strength, and MMWS and QuickDASH. Overall, patients exhibited significant functional improvement at 2 years (VAS: 3-0, P < .001; grip strength: 77.1%-95.6%, P < .001; MMWS: 65-90, P < .001, QuickDASH: 20.5-4.5, P < .001). Median changes in outcome variables and the proportion of patients achieving minimal clinically important difference for the QuickDASH were similar among groups. Seventy-eight patients (97%) achieved distal radioulnar joint stability, and 70 patients (87%) were satisfied with treatment. CONCLUSIONS: Although this current study has insufficient statistical power, the available data suggest that patients with a TFCC foveal tear who underwent arthroscopic transosseous repair surgery more than 12 months after injury could expect to experience similar functional improvement compared with patients who underwent surgery within 6 months or between 6 and 12 months following injury. LEVEL OF EVIDENCE: Level III, retrospective comparative study.