Yonsei Sarang Hospital

To achieve a positive functional prognosis in orthopedic surgery, particularly in shoulder surgeries, effective rehabilitation is essential. Recently, there has been growing interest in the use of virtual reality (VR) in the field of orthopedics, particularly for preoperative education and training, as well as clinical and home-based rehabilitation. This report describes the process of developing an application utilizing Meta Quest 2 VR technology (Meta, CA, USA) for rehabilitation after shoulder surgery. This application assists patients in performing postoperative exercises at home by wearing VR equipment tailored to their postoperative weeks. The advantages of VR rehabilitation lie in overcoming the limitations of traditional rehabilitation methods and providing patients with a better rehabilitation experience. Moreover, automating the rehabilitation process and reducing patients' visits to clinics can lead to cost savings. This report raises expectations for the potential and scalability of VR utilization, extending beyond orthopedics to other fields. In addition, it anticipates that with better feedback and motivation, the rehabilitation effects for patients can be further enhanced.

Focal knee arthroplasty is an attractive alternative to knee arthroplasty for young patients because it allows preservation of a large amount of bone for potential revisions. However, the mechanical behaviour of cartilage has not yet been investigated because it is challenging to evaluate in vivo contact areas, pressure, and deformations from metal implants. Therefore, this study aimed to determine the contact pressure in the tibiofemoral joint with a focal knee arthroplasty using a finite element model. The mechanical behaviour of the cartilage surrounding a metal implant was evaluated using finite element analysis. We modelled focal knee arthroplasty with placement flush, 0.5 mm deep, or protruding 0.5 mm with regard to the level of the surrounding cartilage. We compared contact stress and pressure for bone, implant, and cartilage under static loading conditions. Contact stress on medial and lateral femoral and tibial cartilages increased and decreased, respectively, the most and the least in the protruding model compared to the intact model. The deep model exhibited the closest tibiofemoral contact stress to the intact model. In addition, the deep model demonstrated load sharing between the bone and the implant, while the protruding and flush model showed stress shielding. The data revealed that resurfacing with a focal knee arthroplasty does not cause increased contact pressure with deep implantation. However, protruding implantation leads to increased contact pressure, decreased bone stress, and biomechanical disadvantage in an in vivo application. These results show that it is preferable to leave an edge slightly deep rather than flush and protruding.

Objectives: Excessive accumulation of extravascular lung water impairs respiratory gas exchange and results in respiratory distress. Real-time radiofrequency signals of ultrasound can continuously and quantitatively monitor excessive lung water. This study aims to evaluate the availability of continuous real-time quantitative pulmonary edema monitoring using ultrasound radiofrequency signals and compare it with Pa o2 (partial pressure of arterial oxygen)/F io2 (fraction of inspired oxygen) (PF) ratio, conventional lung ultrasound, and the Hounsfield unit of chest computed tomography. Methods: Male Yorkshire pigs (40.5 ± 0.5 kg) were anesthetized and mechanically ventilated. A balanced crystalloid was administered to induce hydrostatic pulmonary edema. Three different infusion rates of 2, 4, and 6 mL/kg per minute were tested to determine the infusion rate for the appropriate swine model. The chest computed tomography and ultrasonography with radiofrequency signals were taken every 5 min during the full inspiration. The ultrasonography scans with radiofrequency signals were measured at the intercostal space where the line crossing the two armpits and the right anterior axillary line intersected. Results: The infusion rate of fluid for the pulmonary edema model was determined to be 6 mL/kg per minute, and a total of four pigs were tested at an injection rate of 6 mL/kg. The adjusted R2 values of regression analysis between the radiofrequency signal and computer tomography Hounsfield score were 0.990, 0.993, 0.988, and 0.993 (all P values <0.05). All radiofrequency signal changes preceded changes in PF ratio or lung ultrasound changes. The area under the receiver operating characteristic curve of the radiofrequency signal for predicting PF ratio <300 was 0.88 (95% confidence interval, 0.82-0.93). Conclusion: We evaluated ultrasound radiofrequency signals to assess pulmonary edema in a swine model that can worsen gradually and showed that quantitative ultrasound radiofrequency signal analysis could assess pulmonary edema and its progression before PF ratio or lung ultrasound changes.

To report the clinical and radiological outcomes of arthroscopic bone grafting and percutaneous K-wire fixation without radial styloidectomy in patients with scaphoid nonunion advanced collapse (SNAC).We retrospectively analyzed the records of 15 patients with SNAC who were treated with arthroscopic bone grafting and percutaneous K-wire fixation and subsequently followed up for a minimum of 1 year between November 2009 and March 2018. The clinical outcomes were evaluated by comparing the range of motion (ROM), grip strength, the modified Mayo Wrist Score, and visual analog scale (VAS) scores for pain, all of which were measured preoperatively and at the last follow-up. The radiologic outcomes were evaluated by comparing the scapholunate (SL) and radiolunate (RL) angles preoperatively and at the last follow-up.All 15 cases of nonunion were resolved. The average radiologic union time was 9.7 ± 1.2 weeks. The average VAS score increased from 5.7 ± 2.3 (range, 2 − 10) preoperatively to 1.3 ± 1.3 (range, 0 − 3) at the last follow-up (P < .05). The average modified Mayo wrist score increased from 58.3 ± 14.0 preoperatively to 80.0 ± 9.2 at the last follow-up (P < .05). The mean ROM of the wrist improved, but there was no statistical significance. At the last follow-up, the mean flexion and radial deviation on the affected side were significantly decreased, and the mean extension on the affected side was significantly improved compared to the normal side (P < .05). The mean preoperative SL and RL angles were 66 ± 11.9° and 7.2 ± 6.8°, respectively, and were decreased to 50.4 ± 7.5° and 6.4 ± 5.2°, respectively, at the last follow-up. The mean SL angle was significantly corrected (P = .01).Arthroscopic bone grafting and percutaneous Kerschner (K)-wire fixation without radial styloidectomy are considered to be very effective methods for correcting scaphoid deformities to treat SNAC stage I. However, caution may be needed during the surgery to prevent reductions in flexion and the radial deviation of the wrist.

BackgroundEvidence of the clinical impact of programmed death-ligand 1 (PD-L1) expression in small cell lung cancer (SCLC) is scarce and conflicting, even though atezolizumab became the first PD-L1 inhibitor approved by the US Food and Drug Administration (FDA) in recent years for the initial treatment of extensive-stage (ES)-SCLC.MethodsWe investigated PD-L1 expression in SCLC tumors using the three validated PD-L1 immunohistochemistry (IHC) assays (SP263, SP142, and 22C3) and assessed the correlation between PD-L1 expression and clinicopathological factors to determine the prognostic value of PD-L1 expression. The three PD-L1 IHC analyses were prospectively used to assess tumor samples of patients with SCLC at diagnosis.ResultsOf the total of 59 patients, 47 patients received the active treatment beyond platinum-based chemotherapy at our institution. PD-L1 expression was positive in 39.0% with SP263, 37.3% with SP142, and 22.0% with 22C3. In a univariate analysis, the positive result of at least one of the three PD-L1 assays and the positive result of the SP142 assay were associated with longer overall survival (OS). A multivariable analysis confirmed that performance status, stage, and the SP142 assay were independent predictors of OS. In subgroup analysis, these results revealed more significant prognostic factors in ES than in limited-stage (LS). In patients with SCLC, especially those with ES, the expression of the SP142 assay is a significant independent prognostic factor.ConclusionsAlthough these results need to be further validated in larger cohorts, this information will benefit clinicians and patients in determining the immunotherapy for patients with ES-SCLC.

The various factors related to the morphometric characteristics of patella make it difficult to produce a standard interpretation of their respective values. A total of 1423 patients participated in this work. The distribution of Insall–Salvati ratios was investigated, and the upper and lower limits of two standard deviations were used to define the patellar alta and baja. An additional method was used, where 2.5% at each end of the distribution was defined as patellar alta and baja. Ratios in the females and males were 0.92 ± 0.14 and 0.87 ± 0.14, respectively. The ratios were considerably higher in females than in males (p &lt; 0.05). Ratios defined for patellar alta and baja were 1.19 and 0.68 for females and 1.13 and 0.58 for males, respectively, when two standard deviations were used. Ratios defined for patellar alta and baja were 1.22 and 0.66 for females and 1.15 and 0.59 for males, respectively, when the extreme 2.5% method was used. No considerable differences in the patellar alta and baja were observed between the two methods. Patellar alta and baja were determined in ratios of more than 1.20 and less than 0.64, respectively. No significant differences in the patellar alta and baja were observed between the genders in the Korean population. Additionally, two standard deviations of the Insall–Salvati index are recommended for defining patellar alta and baja for the Korean population. However, we recommended analyzing the histogram distribution for the population, followed by an analysis of the patellar alta and baja.

BackgroundThis study was designed to evaluate characters of the rotator cuff tear (RCT) recognized after primary shoulder dislocation in patients older than 40.MethodsFrom 2008 to 2019, patients who visited two hospitals after dislocation were retrospectively reviewed. Inclusion criteria were patients over 40 who had dislocation, with magnetic resonance imaging (MRI) undergone. Exclusion criteria were patients who lost to follow-up, combined with any proximal humerus fracture, brachial plexus injury, and previous operation or dislocation history in the ipsilateral shoulder. Also patients who had only bankart or bony bakart lesion in MRI were excluded. We evaluated RCTs that were recognized by MRI after the primary shoulder dislocation with regard to tear size, degree, involved tendons, fatty degeneration, the age when the first dislocation occurred, and the duration until the MRI was evaluated after the dislocation.ResultsFifty-five RCTs were included. According to age groups, the tear size was increased in coronal and sagittal direction, the number of involved tendons was increased, and the degree of fatty degeneration was advanced in infraspinatus muscle. Thirty-two cases (58.2%) conducted MRI after 3 weeks from the first shoulder dislocation event. This group showed that the retraction size of the coronal plane was increased significantly and the fatty accumulation of the supraspinatus muscle had progressed significantly.ConclusionsAge is also a strong factor to affect the feature of RCT after the shoulder dislocation in patients over 40. And the delay of the MRI may deteriorate the degree of tear size and fatty degeneration.

This study investigates the optimization of the ply angle for cartilage regeneration using a composite scaffold for treating knee joint osteoarthritis. We propose a new paradigm for composite scaffold tissue engineering that focuses on the reconstitution of the anatomic fiber architecture and uses constitutive modeling to evaluate the function of the construct. The mechano-regulation algorithm for tissue differentiation was used to determine the influence of the composite scaffold with an optimized ply angle on chondrogenesis in a computational model of knee-joint severe osteoarthritis. The simulation results revealed that the optimized ply-angle composite scaffold, which had similar mechanical properties to the native cartilage, provided the most appropriate biomechanical environment for cartilage regeneration.