Objective We performed a retrospective study to compare the accuracy of preoperative planning using three-dimensional AI-HIP software and traditional two-dimensional manual templating to predict the size and position of prostheses. The purpose of this study was to evaluate the accuracy of AI-HIP in preoperative planning for primary total hip arthroplasty. Methods In total, 316 hips treated from April 2019 to June 2020 were retrospectively reviewed. A typical preoperative planning process for patients was implemented to compare the accuracy of the two preoperative planning methods with respect to prosthetic size and position. Intraclass correlation coefficients (ICCs) were used to evaluate the homogeneity between the actual prosthetic size and position and the preoperative planning method. Results When AI-HIP software and manual templating were used for preoperative planning, the stem agreement was 87.7% and 58.9%, respectively, and the cup agreement was 94.0% and 65.2%, respectively. The results showed that when AI-HIP software was used, an extremely high level of consistency (ICC > 0.95) was achieved for the femoral stem size, cup size, and femoral osteotomy level (ICC = 0.972, 0.962, and 0.961, respectively). Conclusion AI-HIP software showed excellent reliability for predicting the component size and implant position in primary total hip arthroplasty.

Background The direct anterior approach (DAA) and posterior approach (PA) are two of the most common surgical approaches used for total hip arthroplasty (THA) worldwide. The curved anatomical collum femoris-preserving (CFP) stem was designed to preserve the bone of the femoral neck and allow physiologic load transfer along the trabecular systems, which may better restore hip biomechanics, improve triplanar stem stability and improve the long-term survival rate. We believe this study will demonstrate whether the DAA is suitable for THA with CFP stems. Methods The data of patients who underwent primary THA with CFP stems from January 2010 to December 2015 were retrospectively analysed. These patients were divided into two groups (group A, DAA; group B, PA). The approach was selected by the surgeon. The demographic characteristics, preoperative diagnoses, preoperative Harris hip score, preoperative range of motion, postoperative complications, and radiologic measurements (neck-shaft angle, coronal alignment, sagittal alignment, stress shielding, anteversion, neck-preserving ratio, acetabular anteversion, acetabular inclination angle, acetabular depth, anterior-posterior offset, lateral offset, difference in leg length) were recorded for all patients. Results In this study, a total of 248 patients (185 male and 63 female) were included. No significant differences were found between group A and group B in terms of general patient information and radiologic measurements. However, the rate of nerve injury in group A (7/5.5%) was significantly higher than that in group B (1/0.8%) (p = 0.037). At 1 month after surgery, we found a significant difference between the two groups in the Harris hip score (HHS) (71.03 ± 8.04 in group A, 68.39 ± 8.37 in group B, P = 0.014) and forgotten joint score (FJS-12) (50.78 ± 7.57 in group A, 47.68 ± 7.34 in group B, P = 0.001). At 1 year after surgery, the mean FJS-12 score in group A (68.78 ± 7.54) was higher than that in group B (58.84 ± 8.91) (P < 0.001). At 5 years after surgery, the mean FJS-12 score in group A (73.38 ± 7.21) was higher than that in group B (67.16 ± 9.12) (P < 0.001). Post hoc analysis of the 1-month, 1-year, and 5-year postoperative FJS-12 scores using multiple linear regression analysis revealed that an excellent HHS led to good patient satisfaction at each time point. Conclusion In summary, unlike a “standard” femoral stem, whose alignment might be affected by the surgical approach, alignment of the CFP stem is independent from the surgical approach. Even though the DAA had a higher nerve injury rate, nerve injury from the DAA did not typically cause severe dysfunction of the lower extremity. Therefore, decisions regarding the surgical approach for patients undergoing THA with CFP stems can be made primarily based on the preference of the surgeon.

Background The application of short femoral stems is partially restricted in revision surgery. This study will demonstrate the therapeutic effect and unsuitable situation for short stem revision. Methods Demographic characteristics of all patients were recorded in detail (Table 1). Anteroposterior view radiographic examinations of proximal femur are necessary before and after the operation for patients. The primary outcome of interest was the survival rate of the femoral stem at the final follow-up. Risk factors for failure were also investigated. The secondary outcomes of interest included the Harris hip score, excellent to good rate and incidence of complications. The Mann–Whitney U test was performed for comparisons between continuous variables. The chi-square test was performed for comparisons between categorical variables. Cox regression analysis was used to assess the association between potential risk factors and the failure of revision surgery. Results A total of 381 patients with short stems were retrospectively reviewed. There were 188 males and 193 females. The average age and body mass index before revision surgery were 58.85 ± 13.46 years and 23.72 ± 3.40 kg/m2, respectively. The mid-term survival rate of the short femoral component was 94.23%. The prognosis and complications of patients between the two groups were compared. There was no significant difference between the two groups in the Harris score, complication incidence or survival rate of the femoral component. The strongest risk factor in this study was intraoperative periprosthetic femoral fracture during revision surgery (HR = 5.477, 95% CI = 2.156–13.913). Conclusion Three risk factors for failure were identified: ageing, osteoporosis and intraoperative periprosthetic femoral fracture during revision surgery. Therefore, a short femoral stem should be implanted in patients with these risk factors with additional caution.

Objective The osteoclastic bone resorption inhibitors might have positive effect in preventing femoral head collapse in patients with osteonecrosis of the femoral head (ONFH). However, as a novel osteoclastic inhibitor, whether denosumab can prevent collapse in steroid‐induced ONFH remains unknown. This study aims to evaluate the treatment effect of denosumab and the potential protective mechanism. Methods This was a retrospective study. A total of 161 patients with steroid‐induced ONFH who underwent denosumab treatment were reviewed, and 209 untreated patients were selected as controls. Their clinical characteristics and radiological exam results were obtained. Patients were treated with 60 mg denosumab every 6 months for 2 years. The primary outcome was the incidence of femoral head collapse at 2 years after the initial diagnosis of ONFH. Secondary outcomes included the Harris hip score, progression of osteosclerosis, increase in necrotic area, bone marrow oedema relief, and bone mineral density increase in the femoral head. The Mann–Whitney U test and chi‐square tests were performed to identify the differences between the continuous and categorical variables, respectively. A multivariate logistic regression model was built to identify the factors associated with the treatment effect of denosumab. Results The incidence of femoral head collapse was 42.24% (68/161) in the denosumab group and 54.07% (113/209) in the control group (χ2 = 5.094, p = 0.024; relative risk = 0.787, 95% CI = 0.627–0.973). The excellent‐good rates of the Harris hip score were 63.98% (103/161) in the denosumab group and 44.98% (94/209) in the control group (χ2 = 13.186, p < 0.001). The incidence of osteosclerosis progression in the denosumab group was 55.28% (89/161), which was significantly higher than that in the control group (43.54%, 91/209, χ2 = 5.016, p = 0.025). Meanwhile, a significant increase in bone mineral density was identified in 29.19% (47/161) and 7.18% (15/209) of patients in the denosumab and control groups, respectively (χ2 = 31.600, p < 0.001). The osteoclastic cytoplasm expression of LC3‐II was more positive in the control group than in the denosumab group (immunohistochemistry scoring: 3.58 ± 2.27 vs 6.33 ± 2.64, Z = −2.684, p = 0.007). A total of three independent factors were considered to be associated with the positive treatment effect of denosumab, the time of first denosumab administration (OR = 2.010, 95% CI = 1.272–3.177), osteosclerosis (OR = 1.583, 95% CI = 1.024–2.445), and the necrotic area before denosumab administration (medium necrotic area: OR = 2.084, 95% CI = 1.245–3.487; large necrotic area: OR = 2.211, 95% CI = 1.255–3.893). Conclusions The current study demonstrated that denosumab had a positive effect on preventing femoral head collapse in patients with steroid ONFH. This effect might be closely associated with the inhibition of osteoclasts and their autophagy.

AimsThis study aims to evaluate the diagnostic value of blood metagenomic next-generation sequencing (mNGS) in detecting pathogens from patients clinically diagnosed as acute hematogenous osteomyelitis (AHO).MethodsThis retrospective study enrolled 66 patients with AHO. The test results of mNGS and bacterial culture on different samples, including blood and puncture fluid samples, from patients with AHO were compared to explore the diagnostic value of blood mNGS. Besides, this study also explored the efficacy of blood mNGS in decision making for antibiotic administration and analyzed the factors associated with the positive result of blood mNGS.ResultsThe most common causative pathogens were Staphylococcus and Streptococcus. The sensitivity of blood mNGS (77.3%) was higher than that of blood culture (42.4%) (P&lt;0.001), while the turnaround time of blood mNGS (2.1 ± 0.4 d) is much less than that of blood culture (6.0 ± 2.1 d) (P&lt;0.001). Besides, the sensitivity of blood mNGS tests (77.3%) was slightly lower than that of puncture fluid mNGS (89.4%). Furthermore, detection comparison at pathogen level unravels that blood mNGS might be suitable for diagnosing AHO caused by common pathogens, while puncture fluid mNGS could be considered as preferred examination in diagnosing AHO caused by uncommon pathogens. Finally, three independent factors associated with the true positive result of blood mNGS in patients with AHO were identified, including Gram-positive pathogens (OR=24.4, 95% CI = 1.4-421.0 for Staphylococcus; OR=14.9, 95%CI= 1.6-136.1 for other Gram-positive bacteria), body temperature at sampling time (OR=8.2, 95% CI = 0.6-107.3 for body temperature of &gt;38.5°C; OR=17.2, 95% CI = 2.0-149.1 for patients who were chilling), and no use of antibiotics before sampling (OR=8.9, 95% CI =1.4-59.0).ConclusionThis is the first report on evaluating and emphasizing the importance of blood mNGS in diagnosing AHO. Blood sample might be an alternative sample for puncture fluid for mNGS, and its extensive application in diagnosing AHO could be expected.