Establishing an optimal central sensitization inventory cut-off value affecting postoperative outcomes of osteotomy around the knee.

BACKGROUND: Central sensitization has a significant effect on pain after osteotomy around the knee (OAK). The central sensitization inventory (CSI) score is considered disease specific, and the appropriate cut-off values for OAK are unclear. The purpose of this study was to establish the optimal CSI cut-off value affecting the postoperative outcomes of OAK based on the postoperative knee injury and osteoarthritis outcome score (KOOS). METHODS: Patients who underwent OAK for medial compartment knee osteoarthritis were included. The postoperative KOOS symptoms, pain, and activities of daily living (ADL) were categorized into two groups (score ≥80 each for symptoms, pain, and ADL, and score <80 for any of the three) and were used as factors to calculate receiver operating characteristic curves and the area under the curve with the CSI score. Cut-off values were calculated using the Youden index and the threshold value closest to the upper left corner. Subsequently, logistic multivariate analysis was performed using the KOOS and the obtained CSI cut-off values and other variables. RESULTS: A total of 173 patients were included in this study. The area under the curve of the model was 0.801 (95 % confidence interval, 0.74-0.87), and a CSI score of 12 was determined as the cut-off value. Logistic multivariate analysis based on the cut-off value showed that only the CSI score (odds ratio, 9.79; 95 % CI, 4.47-21.4; P < 0.01) was significant. CONCLUSIONS: The optimal CSI cut-off value affecting the postoperative outcomes of OAK calculated using the postoperative KOOS was 12, which was supported by multivariate analysis results. Central sensitization assessment with an appropriate cut-off value would allow a more personalized treatment approach and may contribute to a better postoperative outcome.

Steep medial posterior tibial slope angle and ramp lesion are independent risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees.

Background: Delayed anterior cruciate ligament (ACL) reconstruction often causes residual anterolateral rotatory instability (ALRI) and consequent knee osteoarthritis, warranting the recommendation of early ACL reconstruction within 6 months after injury. Nonetheless, some cases show notable instability, even shortly after injury. The purpose of this study was to identify risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees within 6 months after injury. Methods: Patients with primary ACL reconstruction within 6 months after injury and quantitative triaxial accelerometer measurements of preoperative pivot shift were included. Descriptive statistics were calculated for 11 independent variables (age, gender, time from injury to surgery, KT-1000, knee extension angle, lateral and medial posterior tibial slope angle, medial and lateral meniscus tears, ramp lesion and Tegner active scale). A single regression analysis was performed on the 11 items and acceleration during the pivot shift, and a multiple regression analysis was performed for items with p value less than 0.1. Results: Overall, 111 patients met the inclusion criteria. Single regression analysis showed that medial posterior tibial slope angle, medial meniscus tear and ramp lesion were significantly correlated with acceleration during the pivot shift (p < 0.001, p = 0.04 and p = 0.001). Multiple regression analysis identified medial posterior tibial slope angles and ramp lesions as independent factors for increased preoperative pivot shift (p = 0.005 and 0.01). Conclusion: A steep medial posterior tibial slope angle and ramp lesion were independent risk factors for increased quantitatively measured pivot shift in patients with ACL-deficient knees. Level of Evidence: Level IV, case series study.

A novel methodology utilizing microchip implants to monitor individual activity and body temperature for assessing knee pain in group-housed rats.

The pain assessment in animals is challenging as they cannot verbally express the site and severity of pain. In this study, we tried a small implantable actimeter, "Nanotag", to monitor spontaneous locomotor activity and body temperature in animals suffering from a chemical-induced rat knee arthritis as compared to naïve and steroid-treated rats. Nanotag could detect the decrease in locomotor activity quickly after the arthritis induction and anti-inflammation analgesic treatment by intra-articular injection of steroid significantly improved locomotor activity. These changes were in the same line with those of a conventional knee pain evaluation method (incapacitance test). Nanotag can be utilized as the non-interventional, continuous, and completely objective monitoring the amount of pain in rat knee arthritis model. This traditional yet innovative method may be universally applicable to various pain models and species, making it a worthwhile device for research across diverse fields.

Equivalent Clinical Outcomes Between Anatomical Alignment Versus Mechanical Alignment of Simultaneous Bilateral Total Knee Arthroplasty Using a Posterior-Stabilized Prosthesis During an Average Follow-Up of Five Years: A Prospective Randomized Clinical Trial.

BACKGROUND: This study aimed to investigate the differences in clinical outcomes between anatomical alignment and mechanical alignment in each knee, respectively, in patients who underwent bilateral total knee arthroplasty. METHODS: Bilateral simultaneous total knee arthroplasty using a posterior-stabilized prosthesis was performed between June 2016 and May 2018, with one knee undergoing anatomical alignment and the contralateral knee undergoing mechanical alignment, which was randomized. There were 80 knees in 40 patients (mean age 75 years, range 60 to 87, with 4 men and 36 women) followed up for at least 2 years (mean follow-up 4.9 years, range 2 to 7 years). On the anatomical side, the distal femoral cut was set 2° more valgus to the mechanical axis, and the tibial cut was set to 2 or 3° varus using a specific guide. Implant position and lower extremity alignment were measured using postoperative radiographs and computed tomography images. The range of motion before and after surgery, Knee Society score, patient satisfaction, postoperative 2011 Knee Society questionnaire, and Knee Injury and Osteoarthritis Outcome Scores were evaluated. RESULTS: A significant difference was observed in joint line orientation (0.6 versus 2.9°, P < .001), but not in the postoperative hip-knee-ankle angle between 2 groups. There was one knee in the mechanical alignment group that required revision surgery at 5 years due to implant loosening. Before surgery, the anatomical alignment group had a significantly lower knee extension angle (-7.2 versus -6.0°, P = .035) and Knee Society Score (46.1 versus 49.1, P = .046). No significant difference was observed between the groups except for the 2011 Knee Society Questionnaire satisfaction scores (26.7 versus 25.7, P = .035). More participants preferred the anatomical alignment side postoperatively. CONCLUSIONS: Anatomical and mechanical alignments had similar clinical outcomes in patients undergoing bilateral total knee arthroplasty at a mean of 4.9 years follow-up. LEVELS OF EVIDENCE: Level Ⅰ (Randomized control study).

Low central sensitisation inventory score is associated with better post-operative outcomes of osteotomy around the knee.

PURPOSE: The purpose of this study was to investigate the potential association between central sensitisation inventory (CSI) scores and post-operative patient-reported outcomes (PROs) in patients underwent osteotomy around the knee (OAK), with a CSI cut-off score specific for knee osteoarthritis. METHODS: CSI scores were collected from 173 patients who underwent OAK, along with their knee injury and osteoarthritis outcome score (KOOS) and pain numeric rating scale (NRS) scores. Patients were divided into high-CSI score group and low-CSI score group with a cut-off score of 17. Multivariate linear regression was performed to test the association between CSI scores and post-operative outcomes. Pre-surgery KOOS and NRS scores and the rate of attainment of minimal clinically important difference (MCID) of KOOS scores was analysed as secondary outcomes. RESULTS: Low-CSI score group had significantly higher post-operative KOOS scores and lower pain NRS scores compared to the high-CSI score group (< p = 0.01) after adjusting for confounding factors. For pre-operative scores, only the KOOS-Symptom score was significantly different between the groups (64.7 ± 20.1 when CSI < 17 vs.55.1 ± 19.7 when CSI ≥ 17; p = 0.008). The low-CSI score group had significantly higher MCID achievement rates of KOOS-Pain, Symptom, and ADL than the high-CSI score group (86% vs. 68%; 74% vs. 55%; 86% vs. 67%, respectively; P < 0.05). CONCLUSIONS: This study established an association between post-operative CSI scores ≥ 17 and poorer outcomes following OAK, highlighting the potential value of the CSI in identifying patients in need of more comprehensive peri-operative pain management. LEVEL OF EVIDENCE: Level III. Retrospective comparative study.

Integration of Independent Heat Transfer Mechanisms for Non-Contact Cold Sensation Presentation With Low Residual Heat.

Thermal sensation is crucial to enhancing our comprehension of the world and enhancing our ability to interact with it. Therefore, the development of thermal sensation presentation technologies holds significant potential, providing a novel method of interaction. Traditional technologies often leave residual heat in the system or the skin, affecting subsequent presentations. Our study focuses on presenting thermal sensations with low residual heat, especially cold sensations. To mitigate the impact of residual heat in the presentation system, we opted for a non-contact method, and to address the influence of residual heat on the skin, we present thermal sensations without significantly altering skin temperature. Specifically, we integrated two highly responsive and independent heat transfer mechanisms: convection via cold air and radiation via visible light, providing non-contact thermal stimuli. By rapidly alternating between perceptible decreases and imperceptible increases in temperature on the same skin area, we maintained near-constant skin temperature while presenting continuous cold sensations. In our experiments involving 15 participants, we observed that when the cooling rate was -0.2 to -0.24 °C/s and the cooling time ratio was 30 to 50%, more than 86.67% of the participants perceived only persistent cold without any warmth.

Older Age, Poor Preoperative Quadriceps Muscle Strength, and Residual Pain as Risk Factors for Poor Quadriceps Muscle Strength Recovery at 1 Year After ACL Reconstruction: A TMDU MAKS Study of 402 Patients.

Background: Poor postoperative quadriceps muscle strength recovery after anterior cruciate ligament reconstruction (ACLR) leads to delayed return to sports and lower patient satisfaction. Purpose/Hypothesis: The purpose of this study was to examine factors that affect quadriceps muscle strength 1 year after ACLR. It was hypothesized that older age, poor preoperative quadriceps muscle strength, and residual pain would be risk factors for poor quadriceps muscle strength recovery. Study Design: Case-control study; Level of evidence, 3. Methods: Included were patients from multiple institutions who underwent primary ACLR using autologous hamstring tendon grafts between August 1, 2013, and March 31, 2018, and who had at least 1 year of follow-up data. Patients with past ligamentous injuries in the affected knee, previous injuries or operations in the contralateral knee, accompanying ligament injuries of grade 2 or 3, or inflammatory or other types of osteoarthritis were excluded. Patients were categorized as having muscle strength ≥80% (good strength recovery) or <80% (poor strength recovery) compared with the contralateral leg at 1 year postoperatively. Multivariate logistic regression analysis was performed to investigate the factors influencing postoperative quadriceps muscle strength. In addition, a categorical analysis was conducted based on factors extracted by the multivariate logistic regression analysis. Results: A total of 402 patients were included. Multivariate logistic regression analysis revealed that age at surgery (P = .020), preoperative quadriceps muscle strength (P = .006), and postoperative Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain score (P = .002) were significantly associated with quadriceps muscle strength at 1 year postoperatively. The odds of poor muscle strength recovery according to categorical analysis were 5.0-fold higher for patients aged >40 versus ≤20 years, 4.2-fold higher for those with preoperative quadriceps muscle index <60% versus ≥80%, and 7.7-fold higher for those with a postoperative KOOS-Pain score of <85 versus 100. Conclusion: Older age, poor preoperative quadriceps muscle strength, and low postoperative KOOS-Pain score were risk factors for poor quadriceps muscle strength 1 year after primary ACLR. Surgical indications, including age, preoperative active rehabilitation, and pain control, should be considered for optimization of postoperative quadriceps muscle strength recovery.

Therapeutic effect of C-type natriuretic peptide on persistent pain in a rat knee arthritis model.

BACKGROUND: Intra-articular injection of C-type natriuretic peptide (CNP) at the acute inflammatory stage suppressed fibrotic changes in the infrapatellar fat pad (IFP), articular cartilage degeneration, and persistent pain in a monoiodoacetic acid (MIA)-induced rat knee arthritis model. In this study, we administered CNP during the inflammation subsiding period to evaluate CNP effectiveness in knees with osteoarthritis (OA) pathology. METHODS: 20 male Wistar rats were randomly divided into two groups. The rats received an intra-articular injection of MIA solution in the right knee to induce inflammation-induced joint degeneration. One group subsequently received an intra-articular CNP injection for six consecutive days from day 8, whereas another group received vehicle solution. Pain avoidance behavior tests and histological analyses were conducted to examine the therapeutic effects of CNP. RESULTS: The incapacitance test indicated that the percent weight on the ipsilateral limb decreased after MIA injection by day 4 and continued to decrease until the end of the experiment in the vehicle group, suggesting persistent pain in the knee. Intra-articular injection of CNP reversed the weight-bearing ratio on day 19. Histological evaluation showed that the CNP group had more residual fat tissue in the IFP and fewer calcitonin gene-related peptide-positive nerve endings compared to the vehicle group. CNP could not reverse articular cartilage degeneration. CONCLUSIONS: Intra-articular injection of CNP after the IFP fibrosis onset had no significant effect on OA severity and extent. Nevertheless, CNP might be utilized therapeutically for OA treatment since it can alleviate persistent knee pain and inhibit structural changes in residual fat tissue.

Navigation Method Enhancing Music Listening Experience by Stimulating Both Neck Sides With Modulated Musical Vibration.

We propose a method that stimulates musical vibration (generated from and synchronized with musical signals), modulated by the direction and distance to the target, on both sides of a user's neck with Hapbeat, a necklace-type haptic device. We conducted three experiments to confirm that the proposed method can achieve both haptic navigation and enhance the music-listening experience. Experiment 1 consisted of conducting a questionnaire survey to examine the effect of stimulating musical vibrations. Experiment 2 evaluated the accuracy (deg) of users' ability to adjust their direction toward a target using the proposed method. Experiment 3 examined the ability of four different navigation methods by performing navigation tasks in a virtual environment. The results of the experiments showed that stimulating musical vibration enhanced the music-listening experience, and that the proposed method is able to provide sufficient information to guide the users: accuracy in identifying directions was about 20 °, participants reached the target in all navigation tasks, and in about 80% of all trials participants reached the target using the shortest route. Furthermore, the proposed method succeeded in conveying distance information, and Hapbeat can be combined with conventional navigation methods without interfering with music listening.

High diagnostic accuracy of magnetic resonance imaging in detecting subscapularis tendon tears by focusing on the most superior portion of the subscapularis tendon.

PURPOSE: This study aimed to test the hypothesis that identifying the exact location of the most superior portion of the subscapularis tendon using magnetic resonance imaging (MRI) provides high diagnostic accuracy in detecting subscapularis tendon tears. METHODS: This study included 157 patients who underwent primary arthroscopic rotator cuff repair between 2014 and 2017. All patients underwent conventional 1.5-T MRI in our hospital, within 3 months before surgery. We retrospectively compared the diagnosis of subscapularis tendon tears using MRI based on an anatomical concept focusing on the superior-most insertion point of the subscapularis tendon with intraoperative arthroscopic findings. RESULTS: Subscapularis tendon tears were detected in 80 (51.0%) of the 157 patients during arthroscopic evaluation. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the MRI examination were 90, 83, 85, 89, and 87%, respectively. With a kappa score of 0.83, the concordance rate between the two raters was almost perfect (95% confidence interval, 0.75-0.92). The sensitivities of the oblique-sagittal and axial sequences were 84 and 79%, respectively. CONCLUSIONS: Preoperative MRI evaluation focusing on the most superior portion of the subscapularis tendon demonstrated high diagnostic accuracy in detecting subscapularis tendon tears. To find the most superior portion of the subscapularis tendon tears, it was essential to check the slice at the level of the lesser tubercle tip and its adjacent slice. In addition, the combined observation of oblique-sagittal and axial sequences helped to detect subscapularis tendon tears with higher sensitivity.

Implementation of Tension-Based Compact Necklace-Type Haptic Device Achieving Widespread Transmission of Low-Frequency Vibrations.

The haptic sensation of low-frequency vibration plays a vital role in the music listening experience, but it can be enjoyed only in certain facilities and environments. Many haptic devices have been proposed to convey music audio-induced vibration for various situations. Such devices require powerful, low-frequency vibration output and transmission over a wide area. Making such devices small and user-friendly is difficult, hindering their popularity. To promote haptic devices for music listening, this paper describes a method for developing a practical device using motors and a thread and evaluates this method's effectiveness. The proposed necklace-type device is small (about 55 × 58 × 15 mm), lightweight (58.5 g), and easy to wear, making it suitable for use during everyday travel. In addition, it can transmit low-frequency (20 Hz) vibrations, whose amplitude exceeds airborne vibration in a nightclub, to a wide area across the chest and neck, with a total power consumption of approximately 2 W. Our proposed method will contribute to the development of practical and high-performance haptic devices for music listening.

Anatomical Repair of a Femoral-Sided Avulsion Fracture of the Anterior Cruciate Ligament: A Case Report.

CASE: We report a rare case of femoral-sided avulsion fracture of both the anteromedial and posterolateral bundle attachments of the anterior cruciate ligament (ACL). We performed an arthroscopic double-bundle pull-out repair. At the 1-year follow-up, the patient had no deformity, laxity of the knee, and no limitations when engaging in various sports activities. CONCLUSION: An avulsion fracture of both the anteromedial and posterolateral bundle attachments is a rare injury. Arthroscopically assisted reduction and fixation demonstrated successful achievement of both bone union and good ACL function.

Video-Assisted Thyroidectomy Using a Surgical Energy Device: Initial Experience in a Japanese Single-Center Cohort.

OBJECTIVE: Video-assisted thyroidectomy (VAT) was approved for coverage under the Japanese public health insurance system in 2016. In our department, we introduced VAT in 2018, and we have since been performing the procedure with the assistance of surgical energy devices. We herein summarize our cases undergoing VAT, including a review of points to consider when introducing the procedure, and characteristics of the surgical energy devices. METHODS: We enrolled 24 patients (14 women and 10 men; age: 24-83 years; mean: 59.0 years) with thyroid/parathyroid tumors who underwent VAT between January 2018 and March 2021 at our department. The medical records of the patients were reviewed, and demographic data, clinical characteristics, histological type, treatment outcomes, and complications were analyzed. RESULTS: The surgical energy devices used were LigaSure® in the first 4 cases, Acrosurg®. Scissors S17 in the next 13 cases, and Acrosurg®. Revo S15 in the latest 7 cases. The operation time (range: 72-250 min; mean: 147 min), intraoperative blood loss (range: 5-370 mL; mean: 33 mL), indwelling time of wound drain (range: 2-6 days; mean: 3.5 days), and hospitalization period (range: 3-8 days; mean: 5.5 days) were within acceptable ranges. In this study, it is suggested that Acrosurg®. Revo S15 can shorten the indwelling time and the hospitalization period. There were no serious complications, but 1 patient developed transient vocal cord paralysis, which improved 3 months after surgery. It was suggested that the microwave energy devices, Acrosurg®. Scissors S17 and Acrosurg®. Revo S15, may be more effective with respect to sealing/hemostasis/coagulation capacity and controllability than the high-frequency electrosurgical device, LigaSure®. CONCLUSION: Based on this initial experience, VAT using surgical energy devices appeared to be a safe, effective, and minimally invasive procedure for the treatment of thyroid/parathyroid tumors. Further studies confirming these early findings are needed.

Continuous Collision Detection for Virtual Proxy Haptic Rendering of Deformable Triangular Mesh Models.

Most haptic systems suffer from what is known as the "tunneling" problem, which arises when a virtual object moves or deforms largely towards a small virtual tool. This problem occurs because the displacement of the virtual object is not considered during collision detection and can be solved with Continuous Collision Detection (CCD). Originally, haptic rendering with CCD was proposed for applications with 6 Degrees-of-Freedom (DoF) only. However, 3-DoF is simple to use in, and sufficient for, many applications. In this paper, we focus on CCD with a 3-DoF point-object haptic rendering of dynamic and deformable objects. Since we use the virtual proxy method, we propose a triangle-proxy CCD approach with a complementary process called Proxy Pop-Out to solve this problem. The results show that we are able to solve the "tunneling" problem, even for a small proxy against thin and deformable objects with large motions. In addition, we present probing haptic interactions with deformable objects in a multi-rate haptic rendering system. By using Oriented Particles and Position Based Dynamics, our system is efficient and stable.

Bilateral Hypoplasia of Both Medial and Lateral Menisci Partially Fused With the Cartilage Surface of the Tibial Plateau.

Hypoplastic meniscus is an extremely rare abnormality. The authors present the first case of meniscal hypoplasia with a partial fusion of meniscus and tibial cartilage. A 22-year-old man underwent surgery for a chronic patellar dislocation. Preoperative magnetic resonance imaging and arthroscopy incidentally revealed hypoplasia of both medial and lateral menisci. Moreover, the posterior horn of the medial meniscus and middle body of the lateral meniscus were fused with the cartilage surface of the tibia. Magnetic resonance imaging of the contralateral knee showed similar meniscal anomalies. This case presents an interesting and extremely rare abnormality of the meniscus. [Orthopedics. 2018; 41(6):e884-e887.].

Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) Syndrome with Significant Bilateral Pleural Effusions.

We herein report a rare case of a 66-year-old woman who had synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome with marked sternal osteitis and bilateral pleural effusions. SAPHO syndrome was diagnosed based on the characteristic features of a hyperostotic sternum and thoracic spine. The inflammatory changes of sternal osteitis and involvement of the adjacent soft tissue were assumed to be the cause of the pleural effusions. The effusions decreased during the natural course of the disease and resolved after methotrexate therapy. The pain dramatically decreased with oral tramadol. Physicians should consider the possibility of SAPHO syndrome in patients with anterior chest pain and pleural effusions.

Melorheostosis with recurrent soft-tissue components: a histologically confirmed case.

Melorheostosis is a very rare disorder characterized by irregular cortical thickening seen on radiographs. In this paper, we present a case of melorheostosis with microscopically confirmed soft-tissue components. The patient was a 51-year-old man who complained of severe pain in the lateral aspect of his right knee. The excision of an ossified soft-tissue lesion relieved intractable pain that had lasted 20 years. Microscopically, the cortex of the affected fibula was composed of thick compact bone and the soft-tissue component consisted of dense compact bone without endochondral ossification. The presence of soft-tissue osseous nodules around the joints is one of the specific conditions for melorheostosis and should be differentiated from synovial chondromatosis. The ossified soft-tissue lesion in our patient is to our knowledge the first reported case of the histologically confirmed soft-tissue component of melorheostosis, which differs from that of synovial chondromatosis.