Surgery on admission and following day reduces hip fracture complications: a Japanese DPC study.

INTRODUCTION: The efficacy of early surgery in preventing complications among Japanese elderly patients with hip fractures requires further investigation. This study aims to use a comprehensive Japanese hip fracture case database to determine whether surgery within the day of admission and the following day reduces the incidence of complications and mortality during hospitalization in elderly hip fracture patients. MATERIALS AND METHODS: We retrospectively analyzed the Japanese National Administrative DPC (Diagnosis Procedure Combination) database from April 2016 to March 2022. Approximately 1100 DPC-affiliated hospitals consistently provided medical records with consent for research. The study investigated the association between postoperative pneumonia, deep vein thrombosis, pulmonary embolism, and mortality during hospitalization after propensity score matching, focusing on surgeries conducted on the day of admission and the following day. RESULTS: After one-to-one propensity score matching for age, gender, and comorbidity, we identified 146,441 pairs of patients who underwent surgery either within the day of admission and the following day or after the third day of admission. Surgery on the third day or later was independently associated with increased risks of pneumonia, deep vein thrombosis, pulmonary embolism, and mortality during hospitalization with risk ratios of 1.367 (95% CI 1.307-1.426), 1.328 (95% CI 1.169-1.508), 1.338 (95% CI 1.289-1.388), and 1.167 (95% CI 1.103-1.234), respectively. CONCLUSION: A comprehensive study of elderly Japanese patients with hip fractures in the DPC database showed that surgery on admission and the following day is crucial for preventing complications like pneumonia, deep vein thrombosis, pulmonary embolism, and mortality during hospitalization.

Clinical characteristics and prognosis of patients with incidentally discovered chest wall sarcoma compared with those of symptomatic patients.

OBJECTIVE: Sarcomas of the bone and soft tissues are detected after the onset of pain, detectable mass and related symptoms in the absence of a standardized screening examination. However, primary chest wall sarcomas can be incidentally detected upon chest X-ray or computed tomography. Previous studies of incidental primary chest wall sarcomas lack prognosis and disease-specific clinical data. This study aimed to investigate the prognoses of patients with incidental chest wall sarcomas and compare them with those of symptomatic patients. METHODS: This study included 18 patients diagnosed with primary chest wall sarcoma between 2010 and 2023. Patient information such as age, sex, tumour diameter, tumour location, symptoms, treatment, time to treatment initiation, pathological diagnosis and outcome were retrospectively analysed. RESULTS: Among the 18 patients, the sarcomas were incidentally detected in five by chest X-ray and computed tomography in three and two patients, respectively. The pathological diagnoses of the patients were Ewing sarcoma, Chondrosarcoma grade 1, grade 2, periosteal osteosarcoma and malignant peripheral nerve sheath tumour. The patients had no symptoms at the first visit to our hospital, and no lesions in other organs were detected at the time of the initial examination. At the final follow-up, the patients remained disease-free after radical treatment. The tumour sizes of the five patients were significantly smaller than those of patients with symptoms (P = 0.003). CONCLUSIONS: The incidental detection of chest wall sarcomas and consequent early detection and treatment of tumours improves patient prognosis relative to that of symptomatically diagnosed patients.

Comparative Gene-Expression Analysis of the Ligamentum Flavum of Patients with Lumbar Spinal Canal Stenosis: Comparison between the Dural and Dorsal Sides of the Thickened Ligamentum Flavum.

Thickening of the ligamentum flavum is the main factor in the development of lumbar spinal canal stenosis (LSCS). Although previous studies have reported factors related to ligamentum flavum thickening, its etiology has not been clarified. Furthermore, it is often difficult to set proper controls to investigate the pathologies of thickening due to differences in patient characteristics, such as age, sex, obesity, and comorbidities. This study aimed to elucidate the pathologies of ligamentum flavum thickening by comparing the dural and dorsal sides of the thickened ligamentum flavum in patients with LSCS. Ligamentum flavum samples were collected from 19 patients with LSCS. The samples were divided into the dural and dorsal sides. The dural side was used as a control to assess the pathologies occurring on the dorsal side. Elastic Masson staining was used to assess the elastic fibres. Gene expression levels were comprehensively assessed using quantitative reverse transcription polymerase chain reaction and DNA microarray analyses. Gene ontology analysis was used to identify biological processes associated with differentially expressed genes. The elastic fibres were significantly decreased on the dorsal side of the thickened ligamentum flavum. Genes related to fibrosis, inflammation, tissue repair, remodeling, and chondrometaplasia, such as COL1A2, COL3A1, COL5A1, TGFB1, VEGFA, TNFA, MMP2, COL10A1, and ADAMTS4, were highly expressed on the dorsal side of the thickened ligamentum flavum. The biological processes occurring on the dorsal side of the thickened ligamentum flavum were extracellular matrix organization, cell adhesion, extracellular matrix disassembly, and proteolysis.These are considered important pathologies of ligamentum flavum thickening.

When and how much does the muscle strength recover after arthroscopic superior capsular reconstruction?

BACKGROUND: Recently, arthroscopic superior capsular reconstruction (SCR) has been performed for irreparable large to massive rotator cuff tears and excellent clinical results have been reported. Although the muscle strength is reported to recover, it has not yet been clarified when and how much it recovers. The purpose of this study was to determine the recovery pattern of muscle strength after SCR. METHODS: We retrospectively reviewed 35 patients (mean age, 65 years) who met the following inclusion criteria: (1) patients with large to massive irreparable tears of the rotator cuff including the supraspinatus and infraspinatus tendons; (2) those with severe muscle atrophy and fatty change; (3) those who underwent assessment of muscle quality and strength by magnetic resonance imaging and dynamometry at 6 months, 1 year, and 2 years; (4) those with a minimum follow-up period of 2 years; and (5) those without severe osteoarthritis. The isometric muscle strength of scaption (ie, scapular-plane elevation), internal rotation, and external rotation in adduction was measured twice for each motion by a dynamometer. RESULTS: Relative to the muscle strength on the uninvolved side, the involved side showed 61% ± 21% in scaption, 63% ± 20% in external rotation, and 103% ± 29% in internal rotation at 2 years after surgery. Whereas no significant differences were observed between the 1-year and 2-year follow-up assessments, a significant difference in muscle strength of scaption was found between 6 months and 1 year (P = .0174). Graft retear was seen in 5 cases (14%). There was a trend that the muscle strength of scaption and external rotation in the no-retear group was greater than that in the retear group despite no significant difference (P = .0717 and P = .0824, respectively). CONCLUSION: The recovery of the muscle strength after SCR was observed until 1 year after surgery, and the muscle strength of scaption and external rotation returned to 60% of that on the uninvolved side at 2 years.

Location and Size of the Reverse Hill-Sachs Lesion in Patients with Traumatic Posterior Shoulder Instability.

BACKGROUND: In patients with traumatic posterior shoulder instability, little is known about the precise location and size of the reverse Hill-Sachs lesion. METHODS: Forty-nine shoulders of 47 patients with traumatic posterior instability were included in this study based on the following inclusion criteria: 1) a primary or recurrent traumatic posterior shoulder dislocation, and 2) the initial event was caused by trauma. Patients were excluded if they had: 1) no history of trauma, 2) prior shoulder surgery, 3) no CT examination, or 4) seizure cases. Three-dimensional images of the humerus reconstructed from CT images were reviewed using an image analysis software. The location and size of the reverse Hill-Sachs lesion were measured and described on a clock face on the humeral head. RESULTS: The reverse Hill-Sachs lesion was observed in 25 of 49 shoulders (51%). The reverse Hill-Sachs lesions were located between 1:37 and 2:48. The depth of the reverse Hill-Sachs lesion (mean ± SD) was 5.8 ± 2.2 mm. The extent of the reverse Hill-Sachs lesion was 35° ± 12°. The average orientation of the reverse Hill-Sachs lesion, represented by an angle measured from the 12 o'clock position, was 64° ± 12° and pointing towards 2:09 on a clock face. Length and width of reverse Hill-Sachs lesions were 9.7 ± 4.7 mm, 11.1 ± 3.6 mm, respectively. CONCLUSION: The reverse Hill-Sachs lesion was a semicircular compression fracture located on the anteromedial aspect of the humeral head. Compared with shoulders with anterior shoulder instability, the humeral defect was smaller and located more inferiorly in shoulders with posterior instability.

Statistical shape models that predict native glenoid width based on glenoid height are inaccurate in their current form: a cross-sectional study.

BACKGROUND: The extent of measurement errors of statistical shape models that predict native glenoid width based on glenoid height to subsequently determine the amount of anterior glenoid bone loss is unclear. Therefore, the aim of this study was to (1) create a statistical shape model based on glenoid height and width measured on 3-dimensional computed tomography (3D-CT) and determine the accuracy through measurement errors and (2) determine measurement errors of existing 3D-CT statistical shape models. MATERIALS AND METHODS: A retrospective cross-sectional study included all consecutive patients who underwent CT imaging before undergoing primary surgical treatment of traumatic anterior shoulder dislocation between 2007 and 2022 at the Tohoku University Hospital and affiliated hospitals. Patients were included when instability was unilateral and CT scans of both the injured and contralateral uninjured shoulder were available. 3D segmentations were created and glenoid height and width of the injured and contralateral uninjured side (gold standard) were measured. Accuracy was determined through measurement errors, which were defined as a percentage error deviation from native glenoid width (contralateral uninjured glenoid), calculated as follows: measurement error = [(estimated glenoid width with a statistical shape model - native glenoid width) / native glenoid width] × 100%. A linear regression analysis was performed to create a statistical shape model based on glenoid height according to the formula: native glenoid width = a × glenoid height + b. RESULTS: The diagnosis and procedure codes identified 105 patients, of which 69 (66%) were eligible for inclusion. Glenoid height demonstrated a very strong correlation (r = 0.80) with native glenoid width. The linear regression formula based on this cohort was as follows: native glenoid width = 0.75 × glenoid height - 0.61, and it demonstrated an absolute average measurement error of 5% ± 4%. The formulas by Giles et al, Chen et al and Rayes et al demonstrated absolute average measurement errors of 10% ± 7%, 6% ± 5%, and 9% ± 6%, respectively. CONCLUSION: Statistical shape models that estimate native glenoid width based on glenoid height demonstrate unacceptable measurement errors, despite a high correlation. Therefore, great caution is advised when using these models to determine glenoid bone loss percentage. To minimize errors caused by morphologic differences, preference goes to methods that use the contralateral side as reference.

Does total hip arthroplasty in elderly patients with femoral neck fractures reduce complications?: A Japanese DPC study.

BACKGROUND: The global increase in femoral neck fractures due to aging and osteoporosis is a major clinical challenge. The debate on the optimal surgical intervention for femoral neck fractures remains unresolved. This large-scale study explores femoral neck fractures among the elderly, focusing on the comparative outcomes of Total Hip Arthroplasty (THA) versus Bipolar Hemiarthroplasty (BHA) in Japanese patients. METHODS: Using the Japanese National Administrative Diagnosis Procedure Combination (DPC) database, we studied cases of femoral neck fracture from April 2016 to March 2023, and after propensity score matching by age, sex, and comorbidities, we examined the association between THA, complications, and clinical outcomes, and the usefulness of THA for elderly patients with femoral neck fracture. RESULTS: One-to-one propensity score matching identified 7741 pairs of THA and BHA cases. There was no difference in length of stay between the THA and BHA groups. Significantly more blood transfusions were required in the THA group. There was no significant difference in mortality between the THA and BHA groups, but there was a reduced risk of pneumonia in the THA group, with a ratio of 0.547 (95% CI: 0.418-0.715). On the other hand, the THA group had a higher risk of pulmonary embolism, with a ratio of 1.607 (95% CI: 1.379-1.874). The THA group shows improved discharge rates directly home from the facility where the operation was performed, with a ratio of 1.798 (95% CI: 1.675-1.929). CONCLUSION: The findings of this research indicate that THA is more effective than BHA in enabling elderly Japanese patients with femoral neck fractures to be discharged directly home and in preventing pneumonia, despite concerns about pulmonary embolism. These findings suggest that THA may improve functional prognosis in elderly patients with femoral neck fractures, although there is a trade-off with an increased risk of pulmonary embolism.

Acetabular coverage exerts minimal influence on femoral head collapse and the necessity for surgical intervention in patients with osteonecrosis of femoral head.

PURPOSE: The acetabular coverage in osteonecrosis of the femoral head (ONFH) affects the need for surgical intervention, and the collapse of the femoral head remains unclear. This study aimed to evaluate the relation between the acetabular coverage and the need for surgical treatment and femoral head collapse. METHODS: The study included 158 patients with 252 hips with glucocorticoid administration and idiopathic ONHF without osteoarthritis changes. The mean age at the first visit was 45.2 years, and the mean follow-up period was 92.2 months. All ONFH hips were subsequently divided into two groups: those needing surgical intervention and those without surgery. Additionally, it divided 167 initially non-collapsed hips into those that either later collapsed or not. Radiographic parameters with the centre-edge angle, acetabular roof obliquity, sharp angle, and necrotic location, following the guidelines of the Japanese Investigation Committee, were evaluated. RESULTS: There were no significant differences in radiographic parameters between the 106 hips that underwent surgery and the 146 hips without surgery. Among the 167 hips without initial collapse, 91 eventually collapsed while 76 did not; their radiographic findings have no significant differences. The necrotic locations were significantly larger in hips requiring surgical intervention or femoral head collapse. Furthermore, 21.8% (55 out of 252 hips) had acetabular dysplasia, which did not significantly correlate with the necessity for surgical treatment or the incidence of femoral head collapse. CONCLUSIONS: Acetabular coverage has little effect on the necessity for surgical treatment and femoral head collapse in ONFH patients over a long-term follow-up.

Clinical Outcomes of Bipolar Hemiarthroplasty with a Conjoined Tendon-Preserving Posterior Approach for Femoral Neck Fractures.

Background and Objectives: The conventional posterior approach in the lateral decubitus position is widely used for femoral neck fractures in femoral hemiarthroplasty. Postoperative dislocation is the major problem with this approach. The conjoined tendon-preserving posterior (CPP) approach is a less invasive surgical approach than the conventional posterior approach to the hip, maintains posterior stability, and preserves short external rotators and joint capsules. However, the mention was required to avoid muscle damage and whether muscle damage affects postoperative dislocation or not. The current study aimed to evaluate the clinical results of the CPP approach in hemiarthroplasty for femoral neck fractures and identify muscle damage risk factors. Materials and Methods: This study was a retrospective cohort study and included 170 hips in 168 patients. The mean age at the operation was 81.2 years. The preservation rate of the internal obturator muscle and gemellus inferior muscle and factors related to intraoperative short rotator muscle injury were investigated retrospectively. The postoperative complications and the relation between muscle damage and postoperative dislocation were investigated. Results: In the four hips (2.3%) with the obturator internus muscle damage, thirty-eight hips (22.4%) with gemellus inferior muscle damage were detected; in the muscle-damaged cases, the high body mass index (BMI) was significantly higher. The complication occurred in four hips (2.3%), including postoperative posterior dislocation in one hip without muscle damage (0.6%). Postoperative infection occurred in one hip (0.6%), and peroneal or sciatic nerve paralysis was suspected in two hips (1.1%). Conclusions: Compared to the conventional posterior approach in previous reports, the CPP approach reduces postoperative dislocation. A higher BMI is a risk factor for muscle damage, and the gemellus inferior muscle damage has no effect on postoperative dislocation. The CPP approach for BHA appeared to be an effective treatment method.

Familial Paget's disease of bone with ocular manifestations and a novel TNFRSF11A duplication variant (72dup27).

INTRODUCTION: Paget's disease of bone (PDB) is a skeletal disorder characterized by disorganized bone remodeling due to abnormal osteoclasts. Tumor necrosis factor receptor superfamily member 11A (TNFRSF11A) gene encodes the receptor activator of nuclear factor kappa B (RANK), which has a critical role in osteoclast function. There are five types of rare PDB and related osteolytic disorders due to TNFRSF11A tandem duplication variants so far, including familial expansile osteolysis (84dup18), expansile skeletal hyperphosphatasia (84dup15), early-onset familial PDB (77dup27), juvenile PDB (87dup15), and panostotic expansile bone disease (90dup12). MATERIALS AND METHODS: We reviewed a Japanese family with PDB, and performed whole-genome sequencing to identify a causative variant. RESULTS: This family had bone symptoms, hyperphosphatasia, hearing loss, tooth loss, and ocular manifestations such as angioid streaks or early-onset glaucoma. We identified a novel duplication variant of TNFRSF11A (72dup27). Angioid streaks were recognized in Juvenile Paget's disease due to loss-of-function variants in the gene TNFRSF11B, and thought to be specific for this disease. However, the novel recognition of angioid streaks in our family raised the possibility of occurrence even in bone disorders due to TNFRSF11A duplication variants and the association of RANKL-RANK signal pathway as the pathogenesis. Glaucoma has conversely not been reported in any case of Paget's disease. It is not certain whether glaucoma is coincidental or specific for PDB with 72dup27. CONCLUSION: Our new findings might suggest a broad spectrum of phenotypes in bone disorders with TNFRSF11A duplication variants.

Impact of Octacalcium Phosphate/Gelatin (OCP/Gel) Composite on Bone Repair in Refractory Bone Defects.

In clinical settings, bone grafting is frequently used to treat bone defects. Therefore, the development of bone graft substitutes with superior bone formation ability is expected, instead of autogenous bone grafting. Octacalcium phosphate (OCP) has been developed as a bone graft substitute, and preclinical studies using OCP have reported superior bone formation ability compared with ß-tricalcium phosphate. Furthermore, OCP has been used in composite forms with natural polymers such as collagen and gelatin to improve the usability of OCP, and OCP/collagen composite forms have been clinically applied in the dental field because of their excellent usability and osteogenic potential. This review describes the development and preclinical results of OCP and OCP/gelatin (OCP/Gel) composites and prospects for future applications in orthopedics. The development of bone graft substitutes that achieve a high degree of biodegradability and strength will be needed for the clinical application of OCP composites in orthopedics in the future.

Primary Malignant Lymphoma of the Cauda Equina Diagnosed after Decompression for Lumbar Spinal Stenosis: A Case Report.

Primary malignant lymphoma confinement to the cauda equina is rare. Only 14 cases of primary malignant lymphoma in the cauda equina have been reported. In these cases, the clinical features were similar to those of lumbar spinal canal stenosis (LSCS). This report describes a case of diffuse large B-cell lymphoma of the cauda equina that was diagnosed after decompression surgery for LSCS. An 80-year-old man presented with gait disturbance due to progressive muscle weakness in the lower extremities over the previous two months. He was diagnosed with LSCS, and decompression surgery was performed. However, the muscle weakness worsened after surgery; therefore, he was referred to our department. Plain magnetic resonance imaging (MRI) revealed swelling of the cauda equina. It demonstrated marked homogenous enhancement by gadolinium-diethylenetriamine pentaacetic acid. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) revealed diffuse accumulation of 18F-FDG in the cauda equina. These imaging findings were consistent with those of cauda equina lymphomas. To confirm the diagnosis, we performed an open biopsy of the cauda equina. Histological examination indicated diffuse large B-cell lymphoma. Considering the patient's age and activities of daily living, further treatment was not performed. The patient died four months after the first surgery. Rapid progression of muscle weakness, which cannot be prevented by decompression surgery, and swollen cauda equina on MRI may be signs of this disorder. Gadolinium-enhanced MRI, 18F-FDG PET, and histological investigation of the cauda equina should be performed for diagnosing primary malignant lymphoma of the cauda equina.

Low Young's Modulus TiNbSn Alloy Locking Plates Accelerate Osteosynthesis in Rabbit Tibiae.

A new beta TiNbSn alloy with a low Young's modulus of approximately 40 GPa has been developed to resolve the stress shielding by Young's modulus divergence. In this study, the efficacy of TiNbSn alloy locking plates on bone repair is compared to that of commercially pure titanium (CP-Ti). The TiNbSn alloy and CP-Ti, which have Young's moduli of 49.1 GPa and 107 GPa, respectively, were compared. Male Japanese white rabbits were anesthetized, and osteotomy and osteosynthesis with locking plates were performed on the right tibia. The bone repair was assessed using micro-computed tomography (CT), histomorphometry, immunohistochemistry, and mechanical testing. Micro-CT, histomorphometry, immunohistochemistry, and mechanical testing were performed four weeks after osteotomy. Six weeks after surgery, micro-CT and mechanical testing were performed. Micro-CT analysis at four weeks after surgery showed that the intramedullary fracture callus in the TiNbSn alloy group had more bone volume and numerous bridging structures compared to the CP-Ti group (CP-Ti vs. TiNbSn alloy, 34.3 ± 13.1 mm3 vs. 61.3 ± 19.6 mm3, p = 0.02; mean ± standard deviation). At four weeks post-osteotomy, the healed tibia showed significantly higher strength in the TiNbSn alloy group compared with CP-Ti (CP-Ti vs. TiNbSn alloy, 81.3 ± 31.2 N vs. 133.7 ± 46.6 N, p = 0.04). TiNbSn alloy locking plates had a more positive impact on bone formation and bone strength restoration than the CP-Ti locking plates during the early phase of bone healing.

Facet cysts in the subaxial cervical spine: Case series focused on radiological and histopathological findings with a scoping review.

BACKGROUND: Facet cysts in the subaxial cervical spine are a relatively rare cause of neuropathy. This case series aimed to investigate the radiological and histopathological features and surgical results of these lesions, and provide possible mechanisms of cyst development. METHODS: Thirteen subaxial cervical facet cysts in 12 patients were diagnosed on the basis of magnetic resonance imaging and computed tomography with facet arthrography. Surgical outcomes were evaluated according to the Japanese Orthopaedic Association scores for cervical myelopathy, or Tanaka's scores for cervical radiculopathy. These results were presented in combination with a scoping review of the literature. RESULTS: Seven cysts were found in the posteromedial region, and six in the posterolateral portion of the spinal canal. Computed tomography revealed degeneration of all involved facet joints. All patients underwent decompression, and the mean recovery rates of Japanese Orthopaedic Association scores and Tanaka's scores were 57.1% and 87.5%, respectively. Histopathologically, all cysts were continuous with the degenerated ligamentum flavum. In the scoping review, the patients' mean age was 65.1 years. The cysts were distributed as follows: 3.6% at C2-3, 10.7% at C3-4, 14.3% at C4-5, 5.4% at C5-6, 7.1% at C6-7, and 58.9% at C7-T1. The presenting symptoms were myelopathy (49.4%) and radiculopathy (50.0%). Radiologically, 55% and 45% of the cysts were of the posteromedial and posterolateral types. Of the patients, 76.9% underwent decompression only, and 23.1% had concomitant fusion. Cyst recurrence was not observed in the mean follow-up period of 15.1 months. CONCLUSIONS: The pathogenesis of cysts is closely related to degenerative changes in the facet joint and ligamentum flavum, and rupture in degenerated ligaments can develop into a cavity, which contributes to cyst formation. The scoping review suggests that cyst resection generally results in positive outcomes without recurrence in either decompression alone or concomitant fusion.

How much force is acting on the shoulder joint to create a Hill-Sachs Lesion or reverse Hill-Sachs Lesion?

BACKGROUND: It has not been clarified yet how much force is acting on the shoulder joint to create Hill-Sachs/reverse Hill-Sachs lesions which are commonly observed in patients with anterior or posterior shoulder instability. The purpose of this study was to determine the magnitude of force to create these bony lesions using cadaveric shoulders. METHODS: Fourteen fresh-frozen cadaveric shoulders were used. Compression tests were performed using the universal testing machine. The specimens were randomly divided into two groups. In group A, the posterior humeral head (the bare area and articular cartilage) was first compressed against the anterior glenoid rim to simulate a Hill-Sachs lesion, followed by the anterior humeral head being compressed against the posterior glenoid rim. In group B, the same procedure was repeated in the reverse order. X-ray microcomputed tomography (microCT) was also performed. RESULTS: The maximum compression force to create a Hill-Sachs lesion was 771 ± 214 N (mean ± SD) on the articular cartilage of the posterior humeral head, which was significantly greater than the force of 447 ± 215 N to create it on the bare area (P = 0.0086). Regarding the reverse Hill-Sachs lesions, the maximum compression force was 840 ± 198 N when it was created on the articular cartilage of the anterior humeral head, which was significantly greater than the force of 471 ± 100 N when it was created at the footprint of the subscapularis tendon (P = 0.0238). MicroCT showed multiple breakage of the trabecular bone. CONCLUSION: A force to create a Hill-Sachs lesion or a reverse Hill-Sachs lesion was significantly greater when it was created on the humeral articular cartilage than at the non-cartilage area. Also, the force to create a reverse Hill-Sachs lesion was significantly greater than the one to create a Hill-Sachs lesion.

Long-term results of Chiari pelvic osteotomy on the preservation of hip function with mean follow-up of more than 30 years and its prognostic factors.

BACKGROUND: Clinical outcomes of Chiari pelvic osteotomy for acetabular dysplasia, including conversion to total hip arthroplasty (THA), have not been adequately explored. The purpose of this study was to examine the long-term results and clinical outcomes of Chiari pelvic osteotomy as the primary outcome and to analyze its prognostic factors as the second outcome. METHODS: This study was a multicenter, retrospective cohort study. Ninety-seven patients underwent Chiari pelvic osteotomy at three hospitals between March 1975 and October 1997. The long-term clinical outcomes of Chiari pelvic osteotomy, including conversion to THA and hip pain, were analyzed using the Kaplan-Meier method. In addition, the prognostic factors for conversion to THA after Chiari pelvic osteotomy were evaluated with clinical variables and radiographic parameters. RESULTS: The study included 51 hips in 45 patients (4 men and 41 women) with long-term follow-up. The survival rates assessed by Kaplan-Meier analysis with conversion to THA as an endpoint, were 90.2% (95% confidence interval (CI) 82.0-98.4%) at 20 years and 73.5% (95% CI 61.1-86.0%) at 30 years. In contrast, the Kaplan-Meier survival rates with the Japanese Orthopaedic Association hip score for pain ≤20 as an endpoint, were 86.3% (95% CI 76.8-95.7%) at 20 years and 65.6% (95% CI 52.3-79.0%) at 30 years. Only older age at osteotomy was the significantly poor prognostic factor for conversion to THA, with a hazard ratio of 1.11/year, 95% CI 1.06 to 1.18, (p < 0.01). CONCLUSION: Chiari pelvic osteotomy may still be a good alternative to bony reconstructive surgery for acetabular dysplasia especially in young patients. Only older age at the osteotomy was related to the poor prognosis of preserving hip function.

Genome-Wide Association Study and Transcriptome of Japanese Patients with Developmental Dysplasia of the Hip Demonstrates an Association with the Ferroptosis Signaling Pathway.

This study examined the association between developmental dysplasia of the hip (DDH) and disease-associated loci in a Japanese cohort. A genome-wide association study (GWAS) of 238 Japanese patients with DDH and 2044 healthy individuals was performed. As a replicate, GWAS was also conducted on the UK Biobank data with 3315 cases and matched 74,038 controls. Gene set enrichment analyses (GSEAs) of both the genetics and transcriptome of DDH were performed. Transcriptome analysis of cartilage specimens from DDH-associated osteoarthritis and femoral neck fractures was performed as a control. Most of the lead variants were very low-frequency ones in the UK, and variants in the Japanese GWAS could not be replicated with the UK GWAS. We assigned DDH-related candidate variants to 42 and 81 genes from the Japanese and UK GWASs, respectively, using functional mapping and annotation. GSEA of gene ontology, disease ontology, and canonical pathways identified the most enriched pathway to be the ferroptosis signaling pathway, both in the Japanese gene set as well as the Japanese and UK merged set. Transcriptome GSEA also identified significant downregulation of genes in the ferroptosis signaling pathway. Thus, the ferroptosis signaling pathway may be associated with the pathogenic mechanism of DDH.

Large language model may assist diagnosis of SAPHO syndrome by bone scintigraphy.

OBJECTIVE: In this study, we employed a large language model to evaluate the diagnostic efficacy of radiology reports of bone scintigraphy in the context of identifying SAPHO syndrome, and further examined the potential of such a model to augment the diagnostic procedure. METHODS: Imaging data and clinical information of 151 patients (105/46 women/men, mean age: 53.5 years) who underwent bone scintigraphy for suspected SAPHO syndrome between January 2007 and December 2022 were retrospectively reviewed. ChatGPT-4.0 was used as the large language model. The diagnostic performance of the large language model was verified by comparing the cases judged to have SAPHO syndrome that fulfilled Kahn's classification criteria based on a combination of concise radiology reports and skin lesions such as palmoplantar pustulosis, with cases diagnosed with SAPHO syndrome by rheumatologists based on all clinical information. The diagnostic performance of the large language model was verified. RESULTS: The diagnostic accuracy of a large language model for analyzing bone scintigraphy radiology reports in conjunction with information about skin symptoms, such as palmoplantar pustulosis, achieved a sensitivity of 83.5%, specificity of 69.4%, and an overall accuracy of 76.8%. DISCUSSION: While this research is an initial endeavor dedicated to the utilization of a substantial language model in the creation of a database for imaging diagnostics of rheumatic conditions, it exhibits commendable diagnostic accuracy, particularly for diseases with a wide range of symptoms like SAPHO syndrome, indicating a positive outlook for subsequent studies. CONCLUSION: This research indicates the prospective value of extensive language models in scrutinizing radiology accounts from bone scintigraphy for the diagnosis of SAPHO syndrome.

Assessment of clinical and radiological characteristics of Japanese patients with SAPHO syndrome.

OBJECTIVE: This study aimed to analyse the radiological characteristics and clinical diversity of Japanese patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, a heterogeneous disorder. METHODS: Radiographs and clinical information from 115 Japanese patients (female/male: 81/34, mean age at onset: 48.7 years) diagnosed with SAPHO syndrome between January 2007 and December 2020 were retrospectively reviewed. Additionally, the treatment for SAPHO syndrome was explored. RESULTS: Among the 115 patients, 70 patients had complications, including palmoplantar pustulosis, acne, or psoriasis. Imaging studies included bone scintigraphy, magnetic resonance imaging, computed tomography, and positron emission tomography in 71, 58, 70, and 23 patients, respectively. The most frequent lesions were arthritis and hyperostosis of the sternoclavicular joints in 96 patients; spinal lesions, including sacroiliac arthritis were observed in 85 patients. Peripheral aseptic osteitis was observed in 22 patients, and the tibia was involved in 12. The treatments consisted of analgesics, bisphosphonates, conventional synthetic disease-modifying anti-rheumatic drugs, and biologics (tumour necrosis factor inhibitors and interleukin-23p19 inhibitors) in 85, 15, 23, and 10 patients (8 and 2 patients), respectively. CONCLUSION: Sternoclavicular hyperostosis and pustulosis are frequently observed in patients with SAPHO syndrome. Biological agents were more frequently used in patients with peripheral osteitis and arthritis.

Octacalcium Phosphate/Gelatin Composite (OCP/Gel) Enhances Bone Repair in a Critical-sized Transcortical Femoral Defect Rat Model.

BACKGROUND: Bone grafting is widely used to treat large bone defects. A porous composite of a bioactive octacalcium phosphate material with gelatin sponge (OCP/Gel) has been shown to biodegrade promptly and be replaced with new bone both in animal models of a membranous bone defect and a long bone defect. However, it is unclear whether OCP/Gel can regenerate bone in more severe bone defects, such as a critical-size transcortical defect. QUESTIONS/PURPOSES: Using an in vivo rat femur model of a standardized, transcortical, critical-size bone defect, we asked: Compared with a Gel control, does OCP/Gel result in more newly formed bone as determined by (1) micro-CT evaluation, (2) histologic and histomorphometric measures, and (3) osteocalcin staining and tartrate-resistant acid phosphatase staining? METHODS: Thirty-four 12-week-old male Sprague-Dawley rats (weight 356 ± 25.6 g) were used. Gel and OCP/Gel composites were prepared in our laboratory. Porous cylinders 3 mm in diameter and 4 mm in height were manufactured from both materials. The OCP/Gel and Gel cylinders were implanted into a 3-mm-diameter transcortical critical-size bone defect model in the left rat femur. The OCP/Gel and Gel were randomly assigned, and the cylinders were implanted. The biological responses of the defect regions were evaluated radiologically and histologically. At 4 and 8 weeks after implantation, CT evaluation, histological examination of decalcified samples, and immunostaining were quantitatively performed to evaluate new bone formation and remaining bone graft substitutes and activity of osteoblasts and osteoclast-like cells (n = 24). Qualitative histological evaluation was performed on undecalcified samples at 3 weeks postimplantation (n = 10). CT and decalcified tissue analysis was not performed blinded, but an analysis of undecalcified specimens was performed under blinded conditions. RESULTS: Radiologic analysis revealed that the OCP/Gel group showed radiopaque regions around the OCP granules and at the edge of the defect margin 4 weeks after implantation, suggesting that new bone formation occurred in two ways. In contrast, the rat femurs in the Gel group had a limited radiopaque zone at the edge of the defect region. The amount of new bone volume analyzed by micro-CT was higher in the OCP/Gel group than in the Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 6.1 ± 1.6 mm 3 versus 3.4 ± 0.7 mm 3 , mean difference 2.7 [95% confidence interval (CI) 0.9 to 4.5]; p = 0.002; intraclass correlation coefficient [ICC] 0.72 [95% CI 0.29 to 0.91]; 8 weeks after implantation: OCP/Gel versus Gel: 3.9 ± 0.7 mm 3 versus 1.4 ± 1.1 mm 3 , mean difference 2.5 [95% CI 0.8 to 4.3]; p = 0.004; ICC 0.81 [95% CI 0.47 to 0.94]). Histologic evaluation also showed there was a higher percentage of new bone formation in the OCP/Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 31.2% ± 5.3% versus 13.6% ± 4.0%, mean difference 17.6% [95% CI 14.2% to 29.2%]; p < 0.001; ICC 0.83 [95% CI 0.53 to 0.95]; 8 weeks after implantation: OCP/Gel versus Gel: 28.3% ± 6.2% versus 9.5% ± 1.9%, mean difference 18.8% [95% CI 11.3% to 26.3%]; p < 0.001; ICC 0.90 [95% CI 0.69 to 0.97]). Bridging of the defect area started earlier in the OCP/Gel group than in the Gel group at 4 weeks after implantation. Osteocalcin immunostaining showed that the number of mature osteoblasts was higher in the OCP/Gel group than in the Gel group at 4 weeks (OCP/Gel versus Gel: 42.1 ± 6.5/mm 2 versus 17.4 ± 5.4/mm 2 , mean difference 24.7 [95% CI 16.2 to 33.2]; p < 0.001; ICC 0.99 [95% CI 0.97 to 0.99]). At 4 weeks, the number of osteoclast-like cells was higher in the OCP/Gel composite group than in the Gel group (OCP/Gel versus Gel: 3.2 ± 0.6/mm 2 versus 0.9 ± 0.4/mm 2 , mean difference 2.3 [95% CI 1.3 to 3.5]; p < 0.001; ICC 0.79 [95% CI 0.35 to 0.94]). CONCLUSION: OCP/Gel composites induced early bone remodeling and cortical bone repair in less time than did the Gel control in a rat critical-size, transcortical femoral defect, suggesting that OCP/Gel could be used as a bone replacement material to treat severe bone defects. CLINICAL RELEVANCE: In a transcortical bone defect model of critical size in the rat femur, the OCP/Gel composite demonstrated successful bone regeneration. Several future studies are needed to evaluate the clinical application of this interesting bone graft substitute, including bone formation capacity in refractory fracture and spinal fusion models and the comparison of bone strength after repair with OCP/Gel composite to that of autologous bone.