Immune-related Adverse Event with Checkpoint Inhibitors Might Be an Emerging Underlying Disease of Steroid-related Osteonecrosis of the Femoral Head: A Case Report.

Introduction: Immune checkpoint inhibitors (ICIs) are increasingly being used in the treatment of advanced metastatic and immunogenic cancers. However, these therapies could cause immune-related adverse events (irAEs), which require high-dose glucocorticoid administration. Case Report: A 52-year-old man with metastatic renal cell carcinoma received ICI therapy. Two weeks later, he suffered from severe irAEs and received glucocorticoid therapy for 13 months. Twenty-one months after the initiation of glucocorticoid administration, he presented to us with bilateral hip pain and was diagnosed with bilateral osteonecrosis of the femoral head (ONFH). Conclusion: IrAEs associated with ICI therapy might be an emerging underlying disease of ONFH.

Femoral head translation in borderline and definite dysplastic hips during weight-bearing: 2D/3D image registration analysis.

PURPOSE: The aims of this study were to 1) assess femoral head translation during weight-bearing in symptomatic developmental dysplasia of the hip (DDH) and 2) compare it between borderline DDH and definite DDH. METHODS: The study included four individuals with borderline DDH and nine with definite DDH, scheduled for periacetabular osteotomy. Anteroposterior X-ray images of the hip joint were obtained in the standing position, and computed tomography images of the pelvis were obtained in the supine position. Femoral head translation from the supine to a standing position was measured using 2D/3D X-ray image registration. RESULTS: From a supine to a standing position, the femoral head translated 0.3 mm laterally, 0.5 mm anteriorly, and 0.5 mm superiorly on average. The mean femoral head translation in 3D between the supine and standing positions was 1.5 mm. The 3D femoral head translation in the borderline DDH group was significantly greater than that in the definite DDH group. In the definite DDH group, there was a significant correlation between the center edge (CE) angle and 3D femoral head translation (ρ = -0.78, P = 0.012). CONCLUSIONS: Symptomatic DDH showed femoral head translation in the anterior, lateral, and superior directions during weight-bearing. In definite DDH, the amount of femoral head translation was negatively correlated with the CE angle. The amount of 3D translation in patients with borderline DDH was larger than that in definite DDH. Dynamic joint instability during weight-bearing was observed in borderline DDH as well as definite DDH. Treatment to enhance joint stability during weight-bearing is important in both cases.

Imaging Features of Early Diffuse Idiopathic Skeletal Hyperostosis (pre-DISH): Analysis of Progression of Ligament Ossification over 5 Years by Computed Tomography.

Introduction: Some patients who have not been diagnosed with diffuse idiopathic skeletal hyperostosis (DISH) (patients in the preclinical stage of DISH [pre-DISH]) may develop DISH in the future. However, there are currently no clearly defined diagnostic criteria for pre-DISH. This study aims to define pre-DISH by analyzing the change in the ossification extent in each intervertebral space in the thoracic and lumbar spines over time using computed tomography (CT). Methods: Of the patients who underwent CT of the thoracic to pelvic region at least twice from 2009 to 2018, 188 who underwent CT at an interval of 5 years to 5 years and 2 months were enrolled. The prevalence of DISH during the first and second CT scans was investigated. The pre-DISH feature was defined, and the prevalence of pre-DISH on the first CT and the change after 5 years in patients with pre-DISH was investigated. Results: Of the 188 patients, 37 (19.7%) and 48 (25.5%) were diagnosed with DISH on the first and second CT scans, respectively. Pre-DISH was defined as the ossification characterized by the modified Mata score of three contiguous intervertebral spaces with a score of ≥2 points (222; 2 points, ligament ossification of half or more of the intervertebral disc height but incomplete fusion), and 52 patients were diagnosed with pre-DISH. Of the 52 patients with a score of ≥(222), 11 (21.2%) were diagnosed with DISH 5 years later. Conclusions: Patients who have three contiguous intervertebral spaces with a modified Mata score of 2 or 3 points should be considered pre-DISH.

Progression of varus deformity in osteoarthritic knees induces anterior paradoxical motion of the femur during early knee flexion.

PURPOSE: The purpose of this study was to investigate the position of the femur relative to the tibia throughout range of motion in the osteoarthritic knee to evaluate knee kinematics and assess its relationship with the degree of varus deformity. METHODS: In this study, 116 preoperative knees with varus deformity were evaluated using a navigation system. The internal-external, anteroposterior, and mediolateral positions of the femur relative to the tibia were measured at maximum extension, 15°, 30°, 45°, 60°, 90°, 105°, and 120°, and maximum flexion angles. From these parameters, two-dimensional translation of the surgical epicondylar axis was projected onto the tibial axial plane, and the femoral movement was evaluated relative to the tibia. In addition, the knees were retrospectively classified into three groups according to their degrees of preoperative hip-knee-ankle angle: mild (< 10°), moderate (10°-20°), and severe (> 20°). Then, the differences in each parameter between these groups were investigated. The Steel-Dwass test was performed to identify the difference among three groups. Statistical significance was set at p values < 0.05. RESULTS: There was a significant difference in the anteroposterior position of the femur relative to the tibia among the three groups, especially from extension to early flexion (p < 0.05). The anteroposterior position at knee extension deviated posteriorly according to the progression of varus deformity. Rotational and mediolateral translation were not significantly different among the groups. Normal knee kinematics were diminished in almost all cases in each group. In addition, anterior paradoxical motion of the femur during early knee flexion was observed in 45.6% (n = 26), 57.1% (n = 28), and 80.0% (n = 8) of cases in the mild, moderate, and severe groups, respectively. The anteroposterior position of the femur relative to the tibia at knee extension was significantly more posterior in patients with than in those without anterior paradoxical motion (p < 0.0001). CONCLUSION: The anteroposterior position of the femur relative to the tibia changed according to the progression of varus deformity in osteoarthritic knees, especially from knee extension to early flexion. Posterior deviation of the femur at knee extension induced its anteroposterior movement relative to the tibia, resulting in anterior paradoxical motion. LEVEL OF EVIDENCE: III.

Feasibility and applicability of locomotive syndrome risk test in elderly patients who underwent total knee arthroplasty.

OBJECTIVES: The concept of locomotive syndrome (LS) and its evaluation method, the LS risk test, have been applied in an integrated manner to capture the decline in mobility resulting from musculoskeletal disorders. The purpose of this study was to evaluate the impact of total knee arthroplasty (TKA) in the elderly with knee osteoarthritis, a common disorder found in LS. METHODS: A total of 111 patients were registered prior to TKA and postoperatively followed up for 1 year. Three components of the LS risk test (the two-step test, stand-up test, and Geriatric Locomotive Function Scale-25) were assessed pre- and postoperatively. RESULTS: After surgery, all three components of the test showed significant improvements from the baseline. The ratio of Stage 3 LS patients (progressed stage of decrease in mobility) reduced from 82.3% to 33.9% postoperatively. There was no significant difference in the degree of change in the scores between the younger (60-74 years) and older (≥75 years) age groups. CONCLUSIONS: We found that TKA has a major impact in preventing the progression of LS in patients with knee osteoarthritis. The LS risk test is a feasible tool for the longitudinal evaluation of patients with musculoskeletal diseases of varying severity and with multiple symptoms.

Rotational Soft-Tissue Balance Is Highly Correlated with Rotational Kinematics in Total Knee Arthroplasty.

Recovery of normal knee kinematics is critical for improving functional outcomes and patient satisfaction after total knee arthroplasty (TKA). The kinematics pattern after TKA varies from case to case, and it remains unclear how to reproduce normal knee kinematics. The present study aimed to evaluate rotational knee kinematics and soft-tissue balance using a navigation system and to assess the influence of intraoperative soft-tissue balance on the rotational knee kinematics. We evaluated 81 osteoarthritic knees treated with TKA using a posterior stabilized (50 knees) or cruciate retaining (31 knees) prosthesis. Rotational kinematics were assessed at 0, 30, 45, 60, and 90 degrees flexion angles by using a computer-assisted navigation system. Correlation between femorotibial rotational position and measured soft tissue balance was assessed by using Spearman's rank correlation coefficient. Rotational soft-tissue balance (the median angle of rotational stress) was significantly correlated with rotational kinematics (rotational axis of the femur relative to the tibia throughout the range of motion) at all measured angles after TKA. The correlation coefficients between the median angle of rotational stress and rotational kinematics were 0.97, 0.80, 0.74, 0.71, and 0.70 at 0, 30, 45, 60, and 90 degrees of flexion, respectively (p-values <0.0001 in all measured angles). The correlation coefficient increased as the knee approached full extension. Our findings suggest that soft-tissue balance is a key factor for rotational kinematics, following both cruciate-retaining and posterior-stabilized TKA.