PurposeThis study aimed to investigate changes in sarcopenia status and physical function after total knee arthroplasty (TKA) in patients with knee osteoarthritis (KOA).MethodsThis prospective observational study was conducted at a single general hospital. Seventy-one patients with KOA undergoing first TKA were classified into sarcopenia (n = 12) and non-sarcopenia (n = 59) groups based on the 2019 Asian Working Group for Sarcopenia criteria. Outcomes including walking speed, grip strength, skeletal muscle mass index (SMI), Knee Injury and Osteoarthritis Outcome Score (KOOS), knee joint muscle strength, and performance-based tests were evaluated preoperatively and at 6 and 12 months postoperatively. Analysis of covariance (ANCOVA) with age and sex as covariates was used to examine differences in improvement at 6 and 12 months. Clinical equivalence was evaluated using 90% confidence intervals and minimum clinically important differences.ResultsOf the 12 patients with preoperative sarcopenia, 10 (83.3%) improved at 12 months postoperatively. ANCOVA showed significant adjusted mean difference (aMD) of 0.31 for SMI at 12 months. No significant differences were found in grip strength (aMD: 0.60), KOOS pain (aMD: 0.01), or 40-m fast-paced walk test (aMD: -0.03). Clinical equivalence was observed for SMI, grip strength, KOOS pain, and 40-m fast-paced walk test, but not other outcomes.ConclusionsIn patients with KOA and sarcopenia, TKA combined with postoperative rehabilitation was associated with improvements in sarcopenia-related measures. Improvements in gait ability, grip strength, and appendicular skeletal muscle mass were comparable to those observed in non-sarcopenic patients.

Aims:This study aimed to investigate the associations between performance-based outcomes (walking, sit-to-stand, and stair climbing) and impairment-level measures one year after primary unilateral total knee arthroplasty (TKA) using an analytic framework that mitigates multicollinearity. Methods:Prospectively collected data were analyzed in a cross-sectional design. We included 142 patients who underwent primary unilateral TKA. The performance-based outcomes one year postoperatively were the 40 m fast-paced walk test (FPWT), 30 s chair stand test (CST), and 11-step stair-climbing test (SCT). Explanatory variables included age, sex, BMI, one-year postoperative muscle strength (bilateral quadriceps and hamstring strength), pain visual analogue scale (VAS) score, and knee flexion range of motion (ROM; SCT model only). We performed multivariate analyses using multiple linear regression and additionally applied ridge regression to mitigate multicollinearity. Relative importance was quantified using the Lindeman-Merenda-Gold (LMG) method. Results:For the FPWT, the primary determinants were bilateral quadriceps strength, contralateral hamstring strength, and age, while sex and pain VAS scores were lower-importance contributors. For CST, bilateral quadriceps strength, age, and contralateral hamstring strength were the primary determinants, with BMI contributing secondarily. For SCT, contralateral quadriceps strength and age were the main determinants, whereas pain VAS score and knee flexion ROM were additional, lower-importance contributors. Conclusion:One year after TKA, bilateral quadriceps strength played a central role across all tasks. Walking and sit-to-stand performances were additionally associated with contralateral hamstring strength and age, whereas stair performance was influenced by pain control and adequate knee flexion ROM. These findings support personalized rehabilitation strategies that prioritize bilateral quadriceps strengthening and layer-task-specific requirements.

We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measuring hip-knee-ankle (HKA) angle in patients with knee osteoarthritis, by comparing it with radiography. In this prospective study, we analysed 60 knees (30 patients) with knee osteoarthritis. We measured HKA angle using OpenPose and radiography before or after total knee arthroplasty and assessed the test–retest reliability of each method with intraclass correlation coefficient (1, 1). We evaluated the ability to estimate the radiographic measurement values from the OpenPose values using linear regression analysis and used intraclass correlation coefficients (2, 1) and Bland–Altman analyses to evaluate the agreement and error between OpenPose and radiographic measurements. OpenPose had excellent test–retest reliability (intraclass correlation coefficient (1, 1) = 1.000) and excellent agreement with radiography (intraclass correlation coefficient (2, 1) = 0.915), with regression analysis indicating a large correlation (R 2 = 0.865). OpenPose also had a 1.1° fixed error and no systematic error when compared with radiography. This is the first study to validate the use of OpenPose for the estimation of HKA angle in patients with knee osteoarthritis. OpenPose is a reliable and valid tool for measuring HKA angle in patients with knee osteoarthritis. OpenPose, which enables non-invasive and simple measurements, may be a useful tool to assess changes in HKA angle and monitor the progression and post-operative course of knee osteoarthritis. Furthermore, this validated tool can be used not only in clinics and hospitals, but also at home and in training gyms; thus, its use could potentially be expanded to include self-assessment/monitoring.

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin that increases the susceptibility to bacterial infections, in particular, those caused by encapsulated bacteria like pneumococci. Recently, the incidence of invasive pneumococcal disease (IPD) has decreased, as pneumococcal vaccines have become popular. On the other hand, the incidence of IPD caused by non-vaccine serotypes is reported to have increased. Herein, we describe the case of a 69-year-old man with IPD caused by the 23A serotype of pneumococcus, who was subsequently diagnosed as having MM. He had no history of having received the pneumococcal vaccine. He presented with a history of fever and back pain and developed arthralgia in the left hand and right knee. Blood and joint fluid culture were positive for Streptococcus pneumoniae. The cerebrospinal fluid test for pneumococcal antigen was positive, but there was no pleocytosis. Subsequently, clinical examination revealed evidence of pyogenic discitis. The patient was started on intravenous antibiotic therapy, but the back pain worsened, and hypercalcemia and M-protein positivity were noted. Based on a positive result for Bence-Jones protein, we suspected the diagnosis of MM. Pneumococcus serotype 23A is one of the non-vaccine types of pneumococci, and first appeared in Japan after pneumococcal vaccination became common in Japan. Moreover, infections with the serotype 23A pneumococci are reported to be associated with a significantly increased risk for mortality. MM increases the risk of infections with encapsulated bacteria, because of the impaired cell-mediated immunity, insufficient opsonization activity due to impaired function of complement, and humoral-mediated immunodeficiency. The initial manifestation in some cases of MM is IPD. Since our patient had had no symptoms prior to this episode, it is possible that he had subclinical MM and developed IPD. Among patients with IPD, we should pay attention to intercurrent diagnosis of MM, because the combination of IPD and MM is sometimes life-threatening.

Aims We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measurement of knee range of motion after total knee arthroplasty (TKA), in comparison to radiography and goniometry. Methods In this prospective observational study, we analyzed 35 primary TKAs (24 patients) for knee osteoarthritis. We measured the knee angles in flexion and extension using OpenPose, radiography, and goniometry. We assessed the test-retest reliability of each method using intraclass correlation coefficient (1,1). We evaluated the ability to estimate other measurement values from the OpenPose value using linear regression analysis. We used intraclass correlation coefficients (2,1) and Bland–Altman analyses to evaluate the agreement and error between radiography and the other measurements. Results OpenPose had excellent test-retest reliability (intraclass correlation coefficient (1,1) = 1.000). The R 2 of all regression models indicated large correlations (0.747 to 0.927). In the flexion position, the intraclass correlation coefficients (2,1) of OpenPose indicated excellent agreement (0.953) with radiography. In the extension position, the intraclass correlation coefficients (2,1) indicated good agreement of OpenPose and radiography (0.815) and moderate agreement of goniometry with radiography (0.593). OpenPose had no systematic error in the flexion position, and a 2.3° fixed error in the extension position, compared to radiography. Conclusion OpenPose is a reliable and valid tool for measuring flexion and extension positions after TKA. It has better accuracy than goniometry, especially in the extension position. Accurate measurement values can be obtained with low error, high reproducibility, and no contact, independent of the examiner’s skills. Cite this article: Bone Joint Res 2023;12(5):313–320.

Background: Predicting the worsening of flexion range of motion (ROM) during the course post-total knee arthroplasty (TKA) is clinically meaningful. This study aimed to create a model that could predict the worsening of knee flexion ROM during the TKA course using a machine learning algorithm and to examine its accuracy and predictive variables.Methods: Altogether, 344 patients (508 knees) who underwent TKA were enrolled. Knee flexion ROM worsening was defined as ROM decrease of >10(degrees) between 1 month and 6 months post-TKA. A predictive model for worsening was investigated using 31 variables obtained retrospectively. 5 data sets were created using stratified 5-fold cross-validation. Total data (n = 508) were randomly divided into training (n = 407) and test (n = 101) data. On each data set, 5 machine learning algorithms (logistic regression, support vector machine, multilayer perceptron, decision tree, and random forest) were applied; the optimal algorithm was decided. Then, variables extracted using recursive feature elimination were combined; by combination, random forest models were created and compared. The accuracy rate and area under the curve were calculated. Finally, the importance of variables was calculated for the most accurate model. Results: The knees were classified into the worsening (n = 124) and nonworsening (n = 384) groups. The random forest model with 3 variables had the highest accuracy rate, 0.86 (area under the curve, 0.72). These variables (importance) were joint-line change (1.000), postoperative femoral-tibial angle (0.887), and hemoglobin A1c (0.468).Conclusions: The random forest model with the above variables is useful for predicting the worsening of knee flexion ROM during the course post-TKA.(c) 2022 The Authors. Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

It remains to be established whether optical computed tomography (CT)-free and acceleration-based navigation systems differ in terms of implantation accuracy and clinical outcomes for total knee arthroplasty. This randomised prospective study compared the implantation accuracy of these two navigation systems in total knee arthroplasty. Optical CT-free navigation (ExactechGPS) or acceleration-based navigation (KneeAlign2) was randomly assigned to the left or right knee of 45 patients who underwent a single-stage bilateral total knee arthroplasty: the ExactechGPS (n = 45) and KneeAlign2 groups (n = 45) were compared. Component alignments were evaluated using three-dimensional computed tomography and radiography at pre- and post-surgery. Implantation accuracy of the component alignment, proportion of outliers, postoperative range of motion, and Japanese Orthopaedic Association (JOA) score were compared between the systems. The implantation accuracies of the lower-extremity mechanical alignment, coronal femoral component angle, coronal tibial component angle, sagittal femoral component, axial femoral angle, and axial tibial angle had no significant difference between the groups. The implantation accuracy of the sagittal tibial component angle was superior in the ExactechGPS than the KneeAlign2 group (1.3° vs. 1.8°, P = 0.034). The proportions of outliers, range of motion, and JOA score had no significant difference between the groups. In the tibial sagittal plane, there was a significant difference in the implantation accuracy, but its difference did not affect the clinical outcomes. Both navigation systems have clinically acceptable implantation accuracy.

Objectives This study aimed to investigate the effect of diabetes mellitus (DM) on knee extension/flexion angle and its early clinical course after total knee arthroplasty (TKA). Methods Patients who received TKA were retrospectively divided into two groups based on haemoglobinA1c level; the DM group (23 knees) and the control group (23 knees matched for baseline characteristics). The passive knee extension/flexion angle, gait speed and Japanese Orthopaedic Association (JOA) score were evaluated preoperatively and at 1, 6 and 12 months postoperatively. Results There was no significant difference in the passive knee flexion angle at 1 and 6 months postoperatively between the groups (p = .302, p = .160, respectively). The passive knee flexion angle was significantly lower at 12 months postoperatively in the DM group than the control group (p = .014). In the DM group, the passive knee flexion angle at 6 and 12 months significantly decreased compared with that at 1 month postoperatively (p = .021, p < .001, respectively). There were no significant differences in the knee extension angle, gait speed and JOA score between the groups. Conclusion Patients with DM are likely to experience passive knee flexion angle exacerbating from 1 to 6 months after TKA.

: [Purpose] To examine the relationships between the knee flexion angle during the swing period and knee muscle activity during the pre-swing period after total knee arthroplasty (TKA). [Participants and Methods] A total of 24 knees treated with TKA were examined. The knee angle during gait was measured using gait images video-recorded from the sidelines. Electromyography was performed involving the rectus femoris, vastus lateralis, and biceps femoris of the operated leg. The gait assessment was conducted at 4 weeks after surgery. The relationships among the angles of the knee at toe off/when maximally flexed and relative/co-activation index values of each muscle during each phase of gait were analyzed. [Results] The maximum knee flexion angle during the swing period was moderately correlated with the relative muscle activity index value of the rectus femoris and co-activation index value of the vastus lateralis and biceps femoris during the pre-swing period. [Conclusion] The overactivity of the rectus femoris and excessive co-activation of the vastus lateralis and biceps femoris during the pre-swing period may lead to stiff-knee gait.

Tofacitinib is a new small-molecule inhibitor of the JAK/STAT signaling pathway used to treat rheumatoid arthritis. We herein report a case of IgA vasculitis apparently caused by tofacitinib. A 67-year-old woman with rheumatoid arthritis developed IgA vasculitis after taking tofacitinib for 6 months. She presented with proteinuria and purpura of the lower extremities. Biopsy specimens from her skin and kidney were compatible with IgA vasculitis. Following termination of tofacitinib, the patient completely recovered from the IgA vasculitis. Drug-induced IgA vasculitis has been previously described for anti-tumor necrosis factor-(TNF)α therapies, but this is the first report of this adverse effect with anti-JAK therapy.

Background: In TKA, we have used the "projected SEA", which is obtained by projecting the "true SEA" on the distal femoral cutting plane in clinical practice to determine the femoral component rotation. There are no reports examining the accuracy of the "projected SEA". In this study, we investigated the difference between the "true SEA" and "projected SEA". Methods: The present study was a CT-based computer-simulated case series. We evaluated 34 knees without osteoarthritis changes. These patients were selected from the operative schedule prior to THA. We defined the "true SEA" on the 3D model and the "projected SEA" on the cutting plane parallel to the distal femoral axis obtained based on the "true SEA". We changed the cutting angles from 20 flexion to 20 extension, and from five degrees varus to five degrees valgus. We measured the "true SEA angle" and "projected SEA angle" regarding the posterior condylar axis (PCA). Results: The mean "true SEA angle" was 3.04 degrees +/- 1.34 degrees (0.6-5.0). The mean "projected SEA angle" was 3.43 degrees +/- 1.58 degrees at 20 flexion, 3.42 degrees +/- 1.56 degrees at 0 flexion, 3.43 degrees +/- 1.52 degrees at 20 extension, 3.39 degrees +/- 1.59 degrees at five degrees valgus, and 3.39 inverted perpendicular +/- 1.50 degrees at five degrees varus. At each cutting angle, the "projected SEA angle" was significantly larger than the "true SEA angle" (p < 0.001). There was no significant difference between any of the "projected SEA angles" (p > 0.001). Conclusions: We found that the true SEA and projected SEA do not differ significantly (0.39 degrees +/- 0.29 degrees [range 0-1.0]). (C) 2017 Published by Elsevier B.V.

Isolated cuboid fractures are very rare, since they typically occur in combination with midfoot fractures or dislocations. A 61-year-old man presented at our hospital with pain and swelling on the outside of his right foot. The lateral column of his right foot was shortened by approximately 6.5 mm on X-ray. CT showed displacement of the joint surface between the cuboid and the fourth metatarsal, with a 3.5 mm depression. An MRI revealed no other injuries. Based on these findings, we diagnosed the patient with an isolated nutcracker fracture of the cuboid. Using a 1.9 mm arthroscope, we examined the Lisfranc joint. Then the depressed fragments were elevated until the regular joint line was restored. A bone biopsy needle was then used to fill in the large defect with artificial bone. In this case, we did not plate the fracture. Six months after surgery, patient could walk without pain. We report a very rare case of isolated nutcracker fracture of the cuboid. In addition, we suggest our new treatment plan of this fracture.

INTRODUCTION:Great toe dislocation frequently occurs at the metatarsophalangeal joint. However, an irreducible dislocation of the great toe interphalangeal (IP) joint due to an accessory sesamoid bone is relatively unusual.CASE REPORT:A 23-year-old woman suffered a dislocated IP joint of the left great toe. The distal phalanx was plantar subluxated, and the articular surface was misaligned. Ultrasound, magnetic resonance imaging, and computed tomography images did not indicate any factors inhibiting reduction. In addition, the sesamoid bone at the IP joint was found to be rotated in the long-axis direction. The sesamoid bone of the IP joint was hooked from the distal direction and occupied the intercondylar area. IP joint of the left great toe was flexed and the distal phalanx was pushed toward the proximal phalanx during reduction locking with fluoroscopic guidance under local anesthesia, and the dislocation was successfully reduced.DISCUSSION:The sesamoid bone at the IP joint is anatomically located dorsal to the flexor hallucis longus tendon and volar plate. The sesamoid bone fitted exactly in the distal intercondylar area. The sesamoid bone in our patient could be rotated by forcible plantar flexion of the IP joint displaced proximally and hooked into the intercondylar area from the proximal aspect. Then, the distal phalanx was pulled proximally through the volar plate. This is the first report on a plantar dislocation of the IP joint.

Objective. To evaluate the longterm safety and efficacy of subcutaneous tocilizumab (TCZ-SC) as monotherapy in patients with rheumatoid arthritis (RA). Methods. Of 346 patients who received 24 weeks of double-blind treatment with either TCZ-SC monotherapy, 162 mg every 2 weeks (q2w); or intravenous TCZ (TCZ-IV) monotherapy, 8 mg/kg every 4 weeks; 319 patients continued to receive TCZ-SC q2w in the 84-week open-label extension (OLE) of the MUSASHI study (JAPICCTI-101117). Efficacy, safety, and immunogenicity were evaluated for all patients treated with TCZ during 108 weeks. Results. The proportions of patients who achieved American College of Rheumatology 20/50/70 responses, low disease activity [28-joint Disease Activity Score (DAS28) ≤ 3.2], or remission (DAS28 < 2.6) at Week 24 were maintained until Week 108. The incidences of adverse events and serious adverse events were 498.3 and 16.9 per 100 patient-years (PY), respectively. The overall safety of TCZ-SC monotherapy was similar to that of TCZ-IV monotherapy. Rates of injection site reactions (ISR) through 108 weeks remained similar to rates through 24 weeks. ISR were mild and did not cause any patient withdrawals. No serious hypersensitivity events (including anaphylactic reactions) occurred. Anti-TCZ antibodies were present in 2.1% of patients treated with TCZ-SC monotherapy. Conclusion. TCZ-SC monotherapy maintained a favorable safety profile and consistent efficacy throughout the 108-week study. Like TCZ-IV, TCZ-SC could provide an additional treatment option for patients with RA.

Closed, locked intramedullary nailing is now widely accepted for tibial diaphyseal fractures. But there are some concerns about the use of this technique for fractures of the distal metaphysis. The authors have used intramedullary nailings for distal tibial fractures. And the results were examined. Patients and methods There were eleven cases with a mean age of 57 years. For fracture classification, AO-type 43-A fractures were 7 cases, 43-C fractures were 4 casess. All fractures were managed by locked intramedullary nailing (unreamed tibial nailings in 10 cases, Russell-Tailor's nail in one case). The overall results were judged with JOA-score and Burwell's evaluation system. Follow-up information ranging from one to four years was obtained. Results Clinically, all cases were good results. Radiological review revealed satisfactory results in all but one case. One case (AO-type 43-A) had varus deformity of 10 degree respectively because of incomplete fixation of the fracture. Discussion Treatment of distal tibial fractures with involvement of the ankle have not been discussed clearly. In surgical treatment of these fractures, reduction of fibula is important, continuously rigid fixation of tibia and fibula is necessary. Open reduction and plate fixation is associated with high incidences of soft tissue damages. Closed intramedullary nailing seems safe and effective treatment. But, this treatment isn't appropriate for distal, displaced intra-articular plaf and fractures which require careful reconstruction of the articular surface. Conclusion The authors reviewed results of intramedullary nailings for the treatment of distal tibial fractures. Clinically, all cases were good results. Radiological review revealed satisfactory results in all but one case. Closed intramedullary nailing seems safe and effective treatment. (

If a transverse incision can be safely used for total knee arthroplasty (TKA), decreases in scar formation, reduced injury of the infrapatellar branch of the saphenous nerve and improved kneeling motion will be observed.

Total knee arthroplasty (TKA) was carried out on both knee joints for spontaneous bony ankylosis due to rheumatoid arthritis (RA). Preoperative fixation angles were 40°. First, the peroneal nerve was released prior to TKA. Quadriceps snip was performed to evert the patella laterally. Bilateral TKAs were carried out using a stabilized prosthesis. The results showed full extension to 70° flexion at 3 years after the surgery. Absence of pain, maintenance of stability, and walking ability were achieved, without any significant complication. Total knee arthroplasty following takedown of a spontaneous ankylosed knee is an effective procedure under appropriate knee conditions.

Sulfasalazine (salazosulfapyridine) has been used increasingly and successfully for the treatment of rheumatoid arthritis. Azulfidine®EN (salazosulfapyridine; Pharmacia KK Diagnostics, Tokyo, Japan), which dissolves in the intestine, is an improvement over sulfasalazine in terms of diminishing adverse gastrointestinal effects. We report herein on a case treated with salazosulfapyridine for rheumatoid arthritis who developed mild dyspnea on exertion, high fever and diffuse pulmonary infiltrates, reversible on discontinuation of the drug. A histologic diagnosis of acute organizing interstitial pneumonia was made by transbronchial lung biopsy. Because the results of a lymphocyte stimulation test against Azulfidine®EN were negative, we allowed the patient to resume Azulfidine®EN for pain in his elbows under informed consent. However, the patient developed symptoms of fever, dry cough and stomatitis and mild renal dysfunction after two doses. Salazosulfapyridine was permanently discontinued and the patient's symptoms subsided. Laboratory findings returned to normal within 2 weeks. Azulfidine®EN should be added to the list of pharmacologic agents causing infiltrative pulmonary disease and renal dysfunction.