Risk factors of periprosthetic joint infection after hemiarthroplasty for displaced femoral neck fracture in the elderly: Analysis of 1619 cases in the multicenter database.

PURPOSE: This multicenter retrospective study focuses on understanding the incidence, causative bacteria, and risk factors for Periprosthetic Joint Infection (PJI) following hemiarthroplasty in elderly patients with displaced femoral neck fractures (FNF). METHODS: From 2016 to 2020, 1,619 patients were diagnosed with displaced FNFs and treated surgically across 11 centers. After exclusions, 1,438 patients (399 men and 1,039 women) were included in the study, averaging 82.1 years in age and 20.2 kg/m² in BMI, observed over 25.7 months on average. Data on demographics, medical history, surgical details, and complications were described. RESULTS: PJI occurred in 20 of the 1438 patients (1.4%). The causative organism was methicillin-susceptible Staphylococcus aureus in 6 patients and methicillin-resistant S. aureus in 6 patients. In patients' backgrounds, the average age was slightly higher in the non-PJI group (82.1 years) compared to the PJI group (80.4 years). There was a higher percentage of males in the PJI group (45%) than in the non-PJI group (27.5%). Drug history showed that the prevalence of anticoagulant use in the PJI group was 25%. Peripheral vascular disease and diabetes mellitus were more prevalent in the PJI group. Most patients in both groups were independent in daily activities. The blood transfusion rate was significantly higher in the PJI group (50%) than in the non-PJI group (23.8%). Notably, the incidence of hematoma was higher in the PJI group (40%). CONCLUSION: This multicenter retrospective study demonstrates a low incidence (1.4%) of PJI in elderly patients undergoing hemiarthroplasty for FNF, primarily due to Staphylococcus aureus. Increased usage of antiplatelets and anticoagulants, as well as comorbidities related to atherosclerosis, like peripheral vascular disease and diabetes mellitus, were observed in patients with PJI. Additionally, these patients experienced higher rates of blood transfusion and postoperative hematomas, highlighting the need for careful management. It should be noted, however, that this finding is a conclusion limited by study design issues, including the retrospective design, small PJI sample size, and variability in treatment approaches.

Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study.

BACKGROUND: The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja. METHODS: We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja. RESULTS: Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03-4.33, p = 0.042). CONCLUSION: In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.

Does Early and Late Weight Bearing Have an Effect on the Results of Elderly Tibial Plateau Fractures with Internal Fixation?: A Multicenter (TRON Group) Study.

Introduction: There is still no consensus on the length of the non-bearing period required for tibial plateau fractures (TPFs) treated surgically. Several studies showed that full weight bearing immediately postoperatively does not affect fixation or cause joint collapse in patients with TPF. While there are concerns about weight bearing in the elderly due to fragile bone quality, their physical disability often makes it difficult to carry out activities of daily life when weight bearing is not allowed. The purpose of this study was to assess differences in clinical and radiographic outcomes between an early weight-bearing (EWB) group and a non-weight-bearing (NWB) group following TPF in elderly patients. Material and Methods: We extracted the data of 432 patients who suffered TPF from January 2011 to December 2020 from a database which is named TRON. We excluded patients with insufficient follow-up postoperatively, AO type A/C fracture, age < 60 years old, multiple trauma, and those lost to follow-up. Finally, 91 patients were eligible. EWB group patients were encouraged to perform partial weight-bearing walking at ≤ 4 weeks after surgery, whereas NWB group patients were not allowed weight bearing for > 4 weeks after surgery. Baseline intergroup differences were adjusted for by matching age, sex, body mass index, smoking history, and injury mechanism. We compared Knee Society Score (KSS), timing of full weight bearing, and X-ray findings including step-off, tibia plateau angle, plateau slope, and condylar widening in the X-rays between the two groups. Results: There were no significant statistical differences between the EWB group and NWB group after matching. The mean follow-up period was 28.0 (range 12-73) months. All cases did not require reoperation or additional procedures. The median KSS at 12 months or at the last follow up postoperatively was 100 (77-100) vs. 95 (75-100) points (P = 0.33). There were no differences in fracture-related infection rates or wound dehiscence. In the radiological evaluation of EWB and NWB, the correction loss of condylar widening was only significantly greater for EWB compared to NWB. Conclusions: We found that early weight bearing could contribute to increased condylar widening. While our short-term follow-up didn't reveal any significant clinical differences, this highlights the need for long-term follow-up to comprehensively understand the implications of these radiographic changes.

Predictive factors for reoperation after periprosthetic femoral fracture: A retrospective multicenter (TRON) study.

BACKGROUND: The surgical treatment of periprosthetic femoral fracture (PFF) can be technically demanding and it is associated with high rates of complications and repeat surgery. However, repeat surgery is uncommon and few studies have examined survival and the functional prognosis following reoperation after the surgical treatment of PFF. We aimed to estimate the rate of reoperation for any reason, to determine the survival rate after reoperation for PFF, and to identify predictors associated with reoperation after PFF surgery in a multicenter (TRON group) study. METHODS: Two hundred forty-six patients were admitted for treatment of PFF. After excluding patients managed conservatively and those with Vancouver type A fracture, we analyzed 184 patients. Unadjusted risk ratios (RRs) were calculated, and multiple logistic regression was used to calculate adjusted RRs. We used the Kaplan-Meier method to create survival curves and a log-rank test to determine survival from the date of repeat surgery. RESULTS: Fifteen of the 184 patients (8.2 %) underwent reoperation after PFF surgery. The 1-year survival rate after reoperation for PFF was 66.7 % (11 of 15). Vancouver B3 and Vancouver C were identified as independent risk factors for reoperation after PFF surgery (Vancouver B3: Risk ratio [RR] 19.0, 95 % CI 1.10-329 P < 0.001; Vancouver C: RR 13.3, 95 % CI 1.4-123.0, P = 0.023). CONCLUSION: The reoperation rate after PFF surgery and the mortality after reoperation PFF surgery were relatively high. The fracture type is associated with reoperation after PFF surgery.

Clinical Outcomes of a Novel Unidirectional Porous ß-Tricalcium Phosphate Filling in Distal Radius Fracture with Volar Locking Plate Fixation: Secondary Publication of the Japanese Version.

Postoperative loss of correction is a concern in cases of distal radius fracture with bone loss after surgery. The purpose of this study was to evaluate the usefulness of a ß-tricalcium phosphate (ß-TCP) with unidirectional pore structure (Affinos®: Kuraray Co., Ltd, Tokyo, Japan) with internal fixation in patients with bone defects during the correction of distal radius fractures. Thirty-nine patients (40 radii) treated between 2016 and August 2020 were included in the study. There were 8 males and 31 females; the mean age was 70.9 (32-88). The mean postoperative observation period was 14.6 (3.4-24) months. The bone defect that occurred in the surgery was filled with Affinos® and fixed with a locking plate. Radial inclination (RI), volar tilt (VT), and ulnar variance (UV) were evaluated after the operation and at the final observation. The start of absorption and the completion of replacement to the host bone of Affinos® were also evaluated. There were no complications associated with grafts of Affinos®. The mean time of translucent findings around artificial bone was 1.85 (0.5-6) months, and that of complete resorption was 10.6 (1.5-16.5) months after surgery. The mean RI was 21.82° after surgery and 21.16° at final observation. The mean VT was 8.54° after surgery and 8.50° at final observation. The mean UV was -0.3 mm after surgery and 0.5 mm at final observation. Affinos® was resorbed relatively early, and host bone formation was observed. Filling of unidirectional pore structure ß-TCP with internal fixation showed favorable outcomes in the surgery of distal radius fractures with bone defects.

Carbon ion radiotherapy for unresectable primary undifferentiated pleomorphic sarcoma of the 11th thoracic spine: a case report.

Objective: Primary undifferentiated pleomorphic sarcoma (UPS) of the bone is rare. However, the common sites are the knee and proximal femur and humerus, while spinal involvement is rare. We report a case of primary UPS of the 11th thoracic vertebra, where corpectomy would have been difficult and extensive, treated with carbon ion radiotherapy. Case report: A 76-year-old man presented with an osteolytic tumor of the 11th thoracic vertebra on plain computed tomography (CT). The spinal cord was compressed and displaced posteriorly by the tumor on magnetic resonance imaging (MRI), and extraosseous extension was observed. An incisional biopsy was performed, and primary UPS of the 11th thoracic vertebra was diagnosed pathologically. Total en bloc spondylectomy was considered to be challenging because of the extraosseous extension and the patient's age; thus, carbon ion radiotherapy (70.4 GyE / 32 fraction) was performed. Denosumab (120 mg) was administered subcutaneously every four weeks. No adjuvant chemotherapy was administered. Four years post-treatment, imaging revealed a compression fracture of the 11th thoracic vertebra, but there was no recurrence. Conclusion: Despite a poor prognosis and an aggressive course of UPS of the spine, the tumor continues to be controlled without local recurrence four years after carbon ion radiotherapy.

Radiation-induced osteosarcoma in the pubic bone after proton radiotherapy for prostate cancer: a case report.

Objective: Radiation-induced sarcoma (RIS), which develops after radiotherapy, occurs as a secondary sarcoma in the irradiated area after a long latency period following radiation exposure. Patient: A 59-year-old man underwent hormone therapy for prostate cancer, followed by proton therapy (74 GyE) four years ago. Positron emission tomography/computed tomography performed 2.5 years later revealed 18F-FDG accumulation in the left pubis. Three years after proton therapy, the patient developed gradually worsening left inguinal pain and visited our department. Imaging revealed bone destruction with a mixture of osteolysis and osteogenesis in the left pubis and the presence of an extraosseous tumor. Following biopsy, the patient was diagnosed with osteosarcoma. Results: A systemic investigation revealed lung metastasis, and chemotherapy was initiated. The lung metastases shrank, and carbon ion radiotherapy (CIRT, 70.4 GyE) was performed on the left pubic lesion after colostomy. Six months after carbon ion radiotherapy, recurrence was observed in the irradiated field, and CIRT was performed again. However, the patient died 22 months after the initial diagnosis because of cancerous pleurisy and pericarditis. Conclusions: Although RIS is rare, it should be actively identified using biopsy to confirm the diagnosis, keeping in mind that it is an important late complication of radiotherapy.

Conjoined tendon preserving posterior approach in hemiarthroplasty for femoral neck fractures: A prospective multicenter clinical study of 322 patients.

PURPOSE: The posterior approach is widely used in femoral hemiarthroplasty. The major problem with this approach is the high risk of postoperative dislocation. A modified posterior approach, the conjoined tendon preserving posterior approach (CPP), was developed to reduce postoperative dislocations. The objective of this multicenter study was to evaluate the efficacy and safety of hemiarthroplasty performed using the CPP approach for femoral neck fractures. METHODS: A total of 322 patients with femoral neck fracture, from 10 facilities, were prospectively studied. Bipolar hemiarthroplasty using the CPP approach was performed, using the same type of implants. Hip joint movement was not restricted following surgery, regardless of a patient's cognitive status. Final follow-up was performed 9.1 ± 1.5 months after surgery. RESULTS: Hemiarthroplasty was undertaken in 320 patients using the CPP approach. The mean age, operative time, and intraoperative blood loss were 83.3 ± 7.4 years, 70.0 ± 22.7 min, and 134.8 ± 107.9 mL, respectively. No postoperative dislocations were observed during the study period. Intraoperative adverse events related to the hip joint included femoral fractures in five patients (1.6%) and trochanteric fractures in four patients (1.3%). Postoperative hip joint adverse events included a periprosthetic fracture in one patient (0.3%), deep infection in two patients (0.6%), and stem subsidence in one patient (0.3%). Postoperative deaths occurred in 23 patients (7.2%). One patient (0.3%) had a severe non-hip adverse event unrelated to surgery that prevented independent living, while five patients (1.6%) had a moderate non-hip adverse event that required treatment. CONCLUSION: The CPP approach prevented postoperative dislocation following femoral hemiarthroplasty in elderly patients, with no CPP-associated specific adverse events.

Primary spinal cord tumors: review of 678 surgically treated patients in Japan. A multicenter study.

PURPOSE: To clarify the relative frequency of various histopathological primary spinal cord tumors and their features in Japanese people and to compare this data with other reports. METHODS: Primary spinal cord tumor surgical cases from 2000 to 2009, which were registered in our affiliated hospital database were collected. We examined age at surgery, sex, anatomical location, vertebral level of the tumor, and pathological diagnosis in each case. RESULTS: Of the 678 patients in our study, 377 patients (55.6 %) were males and 301 patients (44.4 %) were females (male/female ratio 1.25). The mean age at surgery was 52.4 years. Of these tumors, 123 cases (18.1 %) were intramedullary, 371 cases (54.7 %) were intradural extramedullary, 28 cases (4.1 %) were epidural, and 155 cases (22.9 %) were dumbbell tumors. The pathological diagnoses included 388 schwannomas (57.2 %), 79 meningiomas (11.6 %), 54 ependymomas (8.0 %), 27 hemangiomas (4.0 %), 23 hemangioblastomas (3.4 %), 23 neurofibromas (3.4 %), and 9 astrocytomas (1.3 %). The male/female ratios for schwannomas, meningiomas, ependymomas, hemangiomas, hemangioblastomas, neurofibromas, malignant lymphomas, and lipomas are 1.4, 0.34, 1.3, 1.5, 2.3, 1.3, 2.7 and 2.3, respectively. CONCLUSION: This is the first published research in English on the epidemiology of primary spinal cord tumors in Japanese people. Similar to other reports from Asian countries, our data indicates a higher male/female ratio overall for spinal cord tumors, a higher proportion of nerve sheath cell tumors, and a lower proportion of meningiomas and neuroepithelial tumors compared to reports from non-Asian countries. Data in the current study represent the characteristics of primary spinal cord tumors in Asian countries.