Identifying profiles of stroke patients benefitting from additional training: a latent class analysis approach.

OBJECTIVE: To identify profiles of stroke patient benefitting from additional training, using latent class analysis. DESIGN: Retrospective observational study. PATIENTS: Patients with stroke (n = 6,875) admitted to 42 recovery rehabilitation units in Japan between January 2005 and March 2016 who were registered in the Japan Association of Rehabilitation Database. METHODS: The main outcome measure was the difference in Functional Independence Measure (FIM) scores between admission and discharge (referred to as "gain"). The effect of additional training, categorized as usual care (no additional training), self-exercise, training with hospital staff, or both exercise (combining self-exercise and training with hospital staff), was assessed through multiple regression analyses of latent classes. RESULTS: Applying inclusion and exclusion criteria, 1185 patients were classified into 7 latent classes based on their admission characteristics (class size n = 82 (7%) to n = 226 (19%)). Patients with class 2 characteristics (right hemiparesis and modified dependence in the motor-FIM and cognitive-FIM) had positive FIM gain with additional training (95% confidence interval (95% CI) 0.49-3.29; p < 0.01). One-way analysis of variance revealed that training with hospital staff (95% CI 0.07-16.94; p < 0.05) and both exercises (95% CI 5.38-15.13; p < 0.01) led to a significantly higher mean FIM gain than after usual care. CONCLUSION: Additional training in patients with stroke with right hemiparesis and modified dependence in activities of daily living was shown to improve activities of daily living. Training with hospital staff combined with self-exercise is a promising rehabilitation strategy for these patients.

Robotic-assisted total knee arthroplasty improves the rotational mismatch between femoral and tibial components, but not the forgotten joint score 12: a single-center retrospective cohort study.

PURPOSE: The primary aim of this study was to compare postoperative short-term patient reported outcome measurements (PROMs) and rotational mismatch between femoral and tibial following conventional jig-based total knee arthroplasty (Conv-TKA) versus robotic-assisted TKA (RA-TKA) using three-dimensional computed tomography (3DCT) measurements. METHODS: This retrospective, consecutive case-control trial included 83 patients with varus osteoarthritis of the knee undergoing Conv-TKA versus RA-TKA using bi-cruciate stabilized TKA. The rotational mismatch of the femoral and tibial components between the two groups were compared using 3DCT measurements. PROMs (2011 Knee Society Score (KSS), forgotten joint score-12 (FJS-12), patella score were compared in patients between 1 and 2 years postoperatively. RESULTS: The two groups did not exhibit significant differences in any of the following preoperative factors: age at surgery, body mass index (BMI), preoperative range of motion (ROM), hip-knee-ankle (HKA) angle. There were no significant differences in postoperative HKA angle and tibial rotation angle, the absolute values of the femoral rotational angle and rotational mismatch were significantly smaller in the RA-TKA group than in the Conv-TKA group (both p < 0.01). Neither Postoperative PROMs (2011 KSS: pain, patient satisfaction, patient expectation, advanced activities score) nor patella score differed significantly between the groups, but FJS-12 was significantly better in the Conv-TKA group than in the RA-TKA group (p < 0.01). CONCLUSIONS: RA-TKA did not improve FJS-12 compared to Conv-TKA, but did result in more accurate rotational alignment of femoral component and rotational mismatch between the femoral and tibial components. LEVEL OF EVIDENCE: IV.

Cost-effectiveness of occupational therapy for older adults: a protocol for an updated systematic review.

INTRODUCTION: The ageing populations in developed countries are a global concern, with increasing numbers of older adults facing physical, cognitive and psychological challenges, resulting in reduced quality of life and higher healthcare costs. Healthcare expenditure worldwide has been on the rise, especially among older adults, emphasising the importance of enabling independent living while reducing healthcare costs. Occupational therapy holds promising outcomes in promoting functional independence and enhancing the quality of life for older adults, but research on its cost-effectiveness remains limited. This systematic review aims to evaluate the recent evidence on the cost-effectiveness of occupational therapy interventions for older adults from a pragmatic perspective. METHODS AND ANALYSIS: This systematic review will cover full economic evaluations, including cost-effectiveness, cost-utility and cost-benefit analyses, by reviewing randomised and cluster randomised controlled trials. The participants will be aged over 65 years without disease or disability restrictions. Primary outcomes will be assessed using functional status and quality-of-life assessments. Studies published before July 2023 will be searched in PubMed, Web of Science and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, with no language restrictions. ETHICS AND DISSEMINATION: Ethical approval is not required for this literature-based systematic review. The study's findings will update the evaluation of occupational therapy's cost-effectiveness in older adults and will be made public by publishing them in scholarly journals. PROSPERO REGISTRATION NUMBER: CRD42023453558.

Therapeutic effect of adjuvant therapy added to constraint-induced movement therapy in patients with subacute to chronic stroke: a systematic review and meta-analysis.

PURPOSE: This review investigated the effectiveness of adjuvant therapy combined with constraint-induced movement therapy (CIMT) in improving the paretic upper limb functionality in adults with stroke sequelae during the subacute to chronic rehabilitation phase. MATERIALS AND METHODS: In this systematic review and meta-analysis of randomized controlled trials (RCT), electronic databases, including PubMed, Web of Science, CINAHL, and MEDLINE, were searched. We included RCTs that investigated the outcomes of adjuvant therapy (i.e. other therapies) added to CIMT compared with CIMT alone. Key trial findings were qualitatively synthesized and analyzed. This meta-analysis examined variables, such as mean scores and standard deviations, using the following outcome measures: Fugl-Meyer Assessment (FMA) upper limb items, Action Research Arm Test (ARAT), Amount of Use (AOU) of Motor Activity Log (MAL), and Quality of Movement (QOM) of MAL. RESULTS: Eighteen eligible RCTs were included in the analysis. Adding CIMT to adjunctive therapy significantly improved FMA compared with CIMT alone (mean difference [MD] 4.02, 95% confidence interval [CI] 2.60-5.44; I2 = 85%; 15 studies; 330 participants). Similarly, the ARAT and MAL-AOU scores improved significantly. CONCLUSIONS: CIMT combined with several adjunctive therapies effectively improved upper limb function.

In recent years, clinical trials combining other therapies with Constraint-induced movement therapy (CIMT) have become increasingly common.This study shows that combining CIMT with adjuvant therapy improves upper limb function.Different protocols of the CIMT in each study could be factor that impacted the results of Motor Activity Log.In clinical practice, the findings of this study into their treatment protocols to improve patient outcomes and ensure the effective application of evidence-based rehabilitation strategies.

Analysis of Gait Ability and Patient Reported Outcome Measurements after Robotic-assisted Total Knee Arthroplasty for Osteoarthritis of the Knee with Windswept Deformity.

Introduction: Windswept deformity (WD) refers to valgus deformity in one knee and varus deformity in the other. We performed robotic-assisted (RA) total knee arthroplasty (TKA) for osteoarthritis of the knee with WD, made patient reported outcome measurements (PROMs), and performed gait analysis based on triaxial accelerometery. Case Report: A 76-year-old woman presented to our hospital with bilateral knee pain. Image-free handheld RA TKA was performed on the left knee with severe varus deformity and severe pain during walking. RA TKA was performed on the right knee with severe valgus deformity 1 month later. The RA technique was used to determine implant positioning and the plan for osteotomy intraoperatively, taking into account soft-tissue balance. This made it possible to use a posterior stabilized implant instead of a semi-constrained implant for severe valgus knee deformity with flexion contracture (Krachow classification Type 2). At 1 year after TKA, PROMs were inferior in the knee with pre-operative valgus deformity. Gait ability improved after surgery. Even with the RA technique, it took 8 months to achieve left-right balance while walking and for the variability of the gait cycle to become equivalent to that of a normal knee. Conclusion: Primary RA TKA is a viable option for osteoarthritis of the knee with WD. It took time for the gait ability of both knees to become equal and PROMs were better with the varus deformity compared to before surgery.

Coronal alignment classes after robotic-assisted total knee arthroplasty are not associated with variation in patient-reported outcome measurements: A single-center cohort study.

BACKGROUND: The aims of this study were (1) to use three-dimensional computed tomography (3DCT) measurements to determine whether patients undergoing imageless robotic-assisted total knee arthroplasty (RA-TKA) develop a variety of postoperative distal femoral mechanical angle (FMA), proximal tibial mechanical angle (TMA), and hip-knee-ankle angle (HKA) phenotypes as described by Hirschmann et al, and (2) to compare postoperative patient-reported outcome measurements (PROMs) between these phenotypes. METHOD: Fifty patients with knee osteoarthritis underwent RA-TKA. All surgeries were performed using bicruciate-stabilized TKA. In each case, the postoperative HKA, FMA and TMA were classified into one of Hirschmann's five FMA, five TMA, and seven HKA phenotype categories. We investigated how these phenotypes affected patient satisfaction, 2011 Knee Society Score (KSS) subscale scores, the Forgotten Joint Score-12 (FJS-12) score, and patella scores with anterior knee pain at a mean of 15.1 months after RA-TKA. RESULTS: Coronal alignment angles were assigned to three FMA, four TMA, and five HKA phenotypes. The most common FMA, TMA, and HKA phenotypes were valgus FMA 3° (58%), valgus TMA 3° (60%), and varus HKA 3° (38%). The FMA, TMA, and HKA phenotypes showed no significant differences in any PROMs. CONCLUSIONS: RA-TKA led to various HKA, FMA and TMA phenotypes in the coronal plane, none of which affected PROMs.

Intraoperative joint balancing procedure using an imageless robotic assisted technique does not necessarily result in kinematically aligned bicruciate stabilized total knee arthroplasty.

The primary aim of this study was to retrospectively evaluate the hip- knee- ankle. (HKA) angle and prosthetic alignment with three-dimensional computed tomography (3DCT) measurements in patients who underwent robotic-assisted (RA) TKA, with consideration of the soft tissue envelope via an intraoperative joint-balancing procedure. We hypothesized that intraoperative consideration of soft tissue laxity in individual patients using imageless RA technology will not necessarily result in kinematically aligned bicruciate stabilized total knee arthroplasty (KA TKA). This retrospective study included consecutive patients who underwent RA TKA between 2019 and 2020. The indication for TKA was varus osteoarthritis of the knee. During this period, 60 RA bi-cruciate stabilized TKAs were performed. Prosthetic alignments were measured using computer software with 3DCT. We determined prosthetic positioning and bone resection volume with consideration of the soft tissue envelope using an intraoperative full range of motion joint-balancing procedure during RA TKA. 3DCT scans of the entire lower extremity were taken before and after surgery. Postoperative varus HKA alignment occurred in 58% of patients who underwent RA TKA, 31% of knees were in femoral valgus alignment and tibial varus alignment, and 42% had femoral components in internal rotation among knees with femoral valgus alignment and tibial varus alignment. The mean thickness of the osteotomized medial and lateral posterior condyles of the femur were 11.2 and 9.1 mm, respectively, based on 3DCT measurements. Intraoperative consideration of soft tissue laxity in individual patientsusing an imageless RA technique does not necessarily result in KA bicruciate TKA.

The importance of selecting a cruciate-retaining total knee prosthesis for a patient with a large physiological posterior tibial slope: a case report.

For Japanese individuals, deep bending is inevitable in their daily lives, such as during seiza sitting and kneeling. Thus, achieving a good post-operative range of motion is an important factor in improving patient satisfaction. Even normal knees often have a posterior tibial slope of more than 10°. We report the case of a 76-year-old woman who underwent proximal tibial osteotomy at 8° with the Vanguard Knee cruciate retaining total knee arthroplasty (TKA) system. She required the revision TKA 10 years later due to ultra-high-molecular-weight polyethylene wear and breakage of the posteromedial tibial component.

Higher patellofemoral compressive force does not affect anterior knee pain in anatomical bi-cruciate retaining total knee arthroplasty: In vivo prospective analysis of guided motion prosthesis.

BACKGROUND: The purposes of the present study are 1) to measure intraoperative patellofemoral compressive force in patients undergoing anatomical bi-cruciate retaining total knee arthroplasty and to assess the relationship between intraoperative patellofemoral compressive force and patient reported outcome measurements and 2) to compare patellofemoral compressive force and patient reported outcome measurements among patients who underwent anatomical bi-cruciate retaining, cruciate retaining, and bi-cruciate stabilized total knee arthroplasty. METHODS: Twenty-two patients with varus osteoarthritis of the knee who underwent anatomical bi-cruciate retaining total knee arthroplasty, 20 patients who underwent cruciate retaining total knee arthroplasty, and 24 patients who underwent bi-cruciate stabilized total knee arthroplasty were assessed. Patient reported outcome measurements were evaluated at 1.5 years after surgery. FINDINGS: Intraoperative patellofemoral compressive force was significantly lower with anatomical bi-cruciate retaining total knee arthroplasty than with cruciate retaining total knee arthroplasty at 60° to 140° of flexion and nearly equivalent to intraoperative patellofemoral compressive force with bi-cruciate stabilized total knee arthroplasty at all knee flexion angles examined. With anatomical bi-cruciate retaining total knee arthroplasty, there were no significant correlations between intraoperative patellofemoral compressive force and almost all patient reported outcome measurements except for 2011 Knee Society Score expectations, which was positively correlated with patellofemoral compressive force at 10° of flexion, and Patella score quadriceps strength, which was negatively correlated with patellofemoral compressive force at 60° of flexion. INTERPRETATION: There were no significant correlations between intraoperative patellofemoral compressive force and anterior knee pain after anatomical bi-cruciate retaining total knee arthroplasty. Evidence level: 3.

Intra-Arterial Infusion of Imipenem/Cilastatin Sodium through a Needle Inserted into the Radial Artery as a New Treatment for Refractory Trapeziometacarpal Osteoarthritis.

PURPOSE: To evaluate the efficacy and safety of intra-arterial infusion of temporary embolic material with/without radiographic monitoring via a needle placed into the radial artery to occlude abnormal neovessels for trapeziometacarpal osteoarthritis. MATERIALS AND METHODS: Thirty-one patients having Eaton stage II or III osteoarthritis, with a symptom duration longer than 6 months, resistant to conservative therapy for at least 3 months were prospectively enrolled. All procedures were performed by infusing imipenem/cilastatin sodium through a 24-gauge needle that was percutaneously inserted into the radial artery. Seven patients underwent the procedure with fluoroscopy, and 21 patients underwent the procedure without fluoroscopy. The mean Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, numerical rating scale (NRS), and Patient Global Impression of Change (PGIC) scale were evaluated before and at 2, 6, and 24 months after the first procedure. RESULTS: Technical success was 100%. The mean procedure time (from the beginning of local anesthesia to the removal of needle) was 2.9 minutes ± 1.6. The QuickDASH score improved from the baseline to 2, 6, and 24 months (49.2 ± 11.2 vs 22.1 ± 11.2, 20.9 ± 16.6, and 19.5 ± 16.1, respectively, all P <.001). The NRS improved from the baseline to 2, 6, and 24 months (7.2 ± 1.1 vs 3.1 ± 1.8, 2.8 ± 2, and 2.5 ± 2.1, respectively, all P <.001). Improvement on PGIC was observed in 84%, 81%, and 77% of patients at 2, 6, and 24 months, respectively. No major adverse events were encountered. CONCLUSIONS: Intra-arterial infusion of temporary embolic material is a feasible treatment option for trapeziometacarpal osteoarthritis.

Anatomical bi-cruciate retaining TKA improves gait ability earlier than bi-cruciate stabilized TKA based on triaxial accelerometery data: A prospective cohort study.

BACKGROUND: Total knee arthroplasty (TKA) is a common and cost-effective surgical treatment for osteoarthritis of the knee. However, only 82-89% of patients who performed TKA are satisfied with the postoperative outcomes. Therefore, bi-cruciate retaining (BCR) TKA is re-attracting attention. By retaining the anterior cruciate ligament (ACL), the knee may obtain the kinematic pathway that are closer to the native knee. The aim of the present study is to compare the ability to walk before and after surgery in patients who underwent bi-cruciate retaining total knee arthroplasty (BCR TKA) versus bi-cruciate stabilized (BCS) TKA during the early postoperative period. METHODS: Subjects included patients who underwent BCR TKA (10 knees) and BCS TKA (15 knees). We administered 10-meter gait tests before surgery and at 6 weeks and 3 months after surgery. We collected the following triaxial accelerometery data with a portable gait analyzer: walking time, number of steps, velocity, stride length, and coefficient of variability (CV) of double-leg support time while walking. RESULTS: Patients who underwent BCR TKA improved their gait ability [walking time (p < 0.01), number of steps (p < 0.05), velocity (p < 0.01), and stride length (p < 0.01) more than those who received BCS TKA at 6 weeks after surgery. BCR TKA improved gait ability (walking time, number of steps, velocity, and stride length) more than BCS TKA at 6 weeks after surgery. At 6 weeks after surgery, CV of double-leg support time while walking improved more in the BCR TKA group than in the BCS TKA group (p < 0.05). CONCLUSIONS: BCR TKA is associated with improved gait ability in the early postoperative period.

Robotic-assisted total knee arthroplasty improves the outlier of rotational alignment of the tibial prosthesis using 3DCT measurements.

BACKGROUND: The aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA. METHODS: 41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. The operation durations between both groups were investigated. 3DCT scans of the entire lower extremities were taken before and after the surgery and femoral and tibial alignments in the coronal, sagittal, and axial planes were measured using computer software. The differences in prosthetic alignment and translation between the preoperative 3DCT plan and postoperative 3DCT image were also measured. RESULTS: There were no statistically significant differences in the post-operative outliers of the femorotibial angle between the groups. In the tibial-axial plane, the mean of prosthetic alignment in the anteroposterior plane was 4.0° in the Robot group and 6.7° in the Manual group (p < 0.01). The rate of outliers for tibial-axial alignment in the Robot group was significantly less than in the Manual group (p < 0.01). There were no statistically significant differences in prosthetic translation in the proximal-distal, anterior-posterior and medial-lateral orientations between the groups. CONCLUSIONS: In a radiologic study using 3DCT, robotic-assisted TKA reduced the outliers for rotational alignment of the tibial prosthesis in comparison to conventional TKA, which can lead to improved tracking of the femoral-tibial bearing surfaces.

Robotic-Assisted Total Knee Arthroplasty for Distal Femur Fracture with Lateral Knee Osteoarthritis.

Introduction. Open reduction and internal fixation (ORIF) of compound fractures around the knee in elderly patient raise concerns about long-term postoperative external fixation and complications. Total knee arthroplasty (TKA) has been proposed as an alternative solution. We report a case where robotic-assisted (RA) TKA was used to treat lateral knee osteoarthritis (OA) with distal femur fracture. Case Presentation. A 90-year-old female visited our hospital with complications of sustained knee pain after a fall at home. Fracture line from the trochlea to the intercondylar notch was diagnosed on plain radiographs, and prior to this injury, the patient was receiving conservative treatment for lateral OA. We selected a conventional TKA over ORIF because the latter is associated with residual pain and the need for long-term immobilization, which can lead to other complications. However, the fracture site was the entry point for intramedullary rod, and there was concern that the fracture site would be displaced by conventional TKA. Therefore, the unique aspect of the case is that the technique utilized involved robotic milling using the Navio system while temporarily stabilizing the fracture using two tracker pins. RA TKA could determine osteotomy and implant placement by predicting the postoperative patient's soft tissue balance for no medial loosening and lateral contracture. The arthritic cartilage and bone were then methodically removed using the handheld sculptor. After immobilizing the fracture site with a bone grasper before removing the pin tracker, reaming of the femur and insertion of a stem prosthesis with semiconstrained were performed. Primary RA TKA is a viable option for intra-articular fractures in elderly patients with advanced knee osteoarthritis.

Minimally invasive surgery total knee arthroplasty is less popular, but the prosthesis designed specifically for MIS provides good survival and PROMs with a minimum follow-up of 10 years.

BACKGROUND: The concept of minimally invasive surgery (MIS) was introduced in total knee arthroplasty (TKA) in the late 1990s. The number of MIS TKAs has clearly decreased in recent years. An implant designed specifically for MIS TKA has been used all over the world, but there are no reports of long-term postoperative results. The purpose of this study was to characterize long-term clinical results with a minimum follow-up of 10 years. METHODS: This retrospective study included 109 consecutive patients with 143 NexGen CR-Flex prostheses, which are MIS tibial component prostheses designed specifically for MIS TKA. Twelve-year survival analysis was performed using Kaplan-Meier method. Revision surgery for any reason was the endpoint. Long-term clinical and radiographic results of 74 knees (55%) in 60 patients with more than 10 years of follow-up were analyzed. RESULTS: The cumulative survival rate of the single-radius posterior-stabilized TKA of 74 knees was 94.7% (95% confidence interval, 90-99%) at 12 years after surgery. Seven knees (9%) required additional surgery during the 10-year follow-up because of periprosthetic infections. Mean postoperative Knee Society knee score and functional score were 91 and 74 points, respectively. There were no cases of prosthesis breakage, polyethylene wear, or aseptic loosening of the prosthesis. CONCLUSION: The prosthesis designed specifically for MIS TKA is associated with good survival and clinical results with a minimum follow-up of 10 years, even though MIS TKA has become less popular. LEVEL OF EVIDENCE: III.

Short-term results and surgical technique of arthroscopic centralization as an augmentation for medial meniscus extrusion caused by medial meniscus posterior root tear.

INTRODUCTION: The purpose of this study was to perform medial meniscus (MM) centralization for medial meniscus extrusion (MME) associated with medial meniscus posterior root tear (MMPRT) and to examine the short-term results. The hypothesis is that arthroscopic centralization as an augmentation of MMPRT repair improves clinical outcomes and the extrusion distance of MM in short-term results. MATERIALS AND METHODS: Twenty-six patients (mean age 62.1 ± 6.0 years) who underwent arthroscopic centralization as an augmentation of MMPRT repair were included. Clinical evaluation was performed before and 2 years after surgery using Lysholm score and knee injury and osteoarthritis outcome score (KOOS). Image evaluation used MRI and plain X-ray images. The extrusion distance and MME ratio were compared on MRI images before and 2 years after surgery. The degree of osteoarthritis (OA) was evaluated using Kellgren-Lawrence classification. The degree of OA and hip-knee-ankle (HKA) angle were compared by plane X-ray images before and 2 years after surgery. RESULTS: In clinical results, both Lysholm score and KOOS improved significantly after surgery. In image evaluation, the extrusion distance decreased significantly from 4.8 ± 0.7 mm before surgery to 2.7 ± 0.3 mm 2 years after surgery (p < 0.05). The MME ratio was significantly improved from 40.2 ± 7.0% before surgery to 22.6 ± 3.6% after surgery (p < 0.05). There was no significant difference in HKA angle at 2 years after surgery (p = 0.13). CONCLUSIONS: The arthroscopic centralization for medial meniscal extrusion associated with MMPRT significantly improved clinical outcomes and the extrusion distance of MM. It is also one of the surgical techniques that can suppress medial meniscus extrusion. LEVEL OF EVIDENCE: IV, therapeutic case series.

Midterm Comparison of Tibial Fixation between Posterior Cruciate-Retaining and Substituting Porous Tantalum Total Knee Arthroplasty: Three-Dimensional Computed Tomography Analysis.

Porous tantalum tibial component is durable with excellent bone ingrowth, higher knee scores, and long-term survivorship. However, to our knowledge, the effect of posterior cruciate-retaining (CR) and posterior cruciate-substituting (PS) porous tantalum tibial component has not been reported. The aim of the current study was to investigate the prosthetic bone quality between CR porous tantalum tibial component and PS using three-dimensional multi-detector-row computed tomography (3D-MDCT). Porous twenty-two (22) CR total knee arthroplasties and 22 PS received 3D-MDCT at every 6 months up to 5.5 years postoperatively to assess prosthetic bone quality (bone marrow contents/tissue volumes [BMC/TV, mg/cm3]) underneath the pegs of porous tantalum modular tibial component. Clinical outcomes (Knee Society score [KSS], Western Ontario and McMaster Universities (WOMAC), FJS-12, Patella score) were evaluated at a minimum follow-up period of 5.5 years. No statistically significant differences were found in age, gender, body mass index, KSS, and BMC/TV volumes in the proximal tibia between the two groups before total knee arthroplasty (TKA). There were also no significant differences between the CR and PS groups with regard to BMC/TV at every 6 months up to 5.5 years after TKA. At 5.5 years postoperatively, there was no significant difference between the two groups in terms of the KSS, WOMAC, forgotten joint score (FJS-12), and Patella score. The present study revealed that the prosthetic bone quality of the CR porous tantalum tibial component and PS were equivalent at every 6 months up to 5.5 years after TKA. This study reflects level II evidence.

Posterior tibial slope and anterior post-cam contact can change knee kinematics in extension in bi-cruciate stabilized total knee arthroplasty.

AIMS: This study aims to investigate the effects of posterior tibial slope (PTS) on knee kinematics involved in the post-cam mechanism in bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) using computer simulation. METHODS: In total, 11 different PTS (0° to 10°) values were simulated to evaluate the effect of PTS on anterior post-cam contact conditions and knee kinematics in BCS TKA during weight-bearing stair climbing (from 86° to 6° of knee flexion). Knee kinematics were expressed as the lowest points of the medial and lateral femoral condyles on the surface of the tibial insert, and the anteroposterior translation of the femoral component relative to the tibial insert. RESULTS: Anterior post-cam contact in BCS TKA was observed with the knee near full extension if PTS was 6° or more. BCS TKA showed a bicondylar roll forward movement from 86° to mid-flexion, and two different patterns from mid-flexion to knee extension: screw home movement without anterior post-cam contact and bicondylar roll forward movement after anterior post-cam contact. Knee kinematics in the simulation showed similar trends to the clinical in vivo data and were almost within the range of inter-specimen variability. CONCLUSION: Postoperative knee kinematics in BCS TKA differed according to PTS and anterior post-cam contact; in particular, anterior post-cam contact changed knee kinematics, which may affect the patient's perception of the knee during activities. Cite this article: Bone Joint Res 2020;9(11):761-767.

Erratum to "Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty" [The Knee 27(5) (2020) 1534-1541]".

BACKGROUND: The purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA). METHODS: Fifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique 3° angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis. RESULTS: Intraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS. CONCLUSION: Surgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.

Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty.

BACKGROUND: The purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA). METHODS: Fifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique three-degree angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis. RESULTS: Intraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS. CONCLUSIONS: Surgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.

Identification of Novel Fusion Genes in Bone and Soft Tissue Sarcoma and Their Implication in the Generation of a Mouse Model.

Fusion genes induced by chromosomal aberrations are common mutations causally associated with bone and soft tissue sarcomas (BSTS). These fusions are usually disease type-specific, and identification of the fusion genes greatly helps in making precise diagnoses and determining therapeutic directions. However, there are limitations in detecting unknown fusion genes or rare fusion variants when using standard fusion gene detection techniques, such as reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH). In the present study, we have identified 19 novel fusion genes using target RNA sequencing (RNA-seq) in 55 cases of round or spindle cell sarcomas in which no fusion genes were detected by RT-PCR. Subsequent analysis using Sanger sequencing confirmed that seven out of 19 novel fusion genes would produce functional fusion proteins. Seven fusion genes detected in this study affect signal transduction and are ideal targets of small molecule inhibitors. YWHAE-NTRK3 expression in mouse embryonic mesenchymal cells (eMCs) induced spindle cell sarcoma, and the tumor was sensitive to the TRK inhibitor LOXO-101 both in vitro and in vivo. The combination of target RNA-seq and generation of an ex vivo mouse model expressing novel fusions provides important information both for sarcoma biology and the appropriate diagnosis of BSTS.