A New Method to Predict Postoperative Stem Anteversion in Total Hip Arthroplasty for Developmental Dysplasia of the Hip.

BACKGROUND: Preoperative evaluation of femoral anteversion to predict postoperative stem anteversion aids the selection of an appropriate prosthesis and optimizes the combined anteversion in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). The conventional prediction methods are based on the femoral anteversion measurement at the location of the femoral head and/or neck. However, varied differences between femoral anteversion and postoperative stem anteversion were demonstrated. This study investigated the predictive role of a new method based on the principle of sagittal three-point fixation. METHODS: From January 2017 to December 2018, a total of 133 DDH hips that underwent THA were retrospectively analyzed. There were 76 Crowe type I, 27 type II, and 30 type III hips. The single-wedge stem was used in 49 hips, and the double-wedge stem was used in 84 hips. Preoperative native femoral anteversion at the femoral head-neck junction, anterior cortex anteversion at 2 levels of the lesser trochanter, posterior cortex anteversion at 5 levels of the femoral neck, and postoperative stem anteversion were measured using two-dimensional computed tomography. Predictive anteversion by the new method was calculated as the average anteversion formed by the anterior cortex at the lesser trochanter and the posterior cortex at the femoral neck. RESULTS: For hips with different neck heights, different Crowe types, different stem types, or different femoral anteversions, native femoral anteversion showed widely varied differences and correlations with stem anteversion, with differences ranging from -1.27 ± 8.33° to -13.67 ± 9.47° and correlations ranging from 0.122 (p = 0.705, no correlation) to 0.813. Predictive anteversion formed by the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base showed no significant difference with stem anteversion, with less varied differences (0.92 ± 7.52°) and good to excellent correlations (r = 0.826). CONCLUSION: Adopting our new method, predictive anteversion, measured as the average anteversion of the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base, predicted postoperative stem anteversion more reliably than native femoral anteversion.

Aspirin prevents estrogen deficiency-induced bone loss by inhibiting osteoclastogenesis and promoting osteogenesis.

BACKGROUND: Aspirin is a commonly used antipyretic, analgesic, and anti-inflammatory drug. Numerous researches have demonstrated that aspirin exerts multiple biological effects on bone metabolism. However, its spatiotemporal roles remain controversial according to the specific therapeutic doses used for different clinical conditions, and the detailed mechanisms have not been fully elucidated. Hence, in the present study, we aimed to identify the dual effects of different aspirin dosages on osteoclastic activity and osteoblastic bone formation in vitro and in vivo. METHODS: The effects of varying doses of aspirin on osteoclast and osteoblast differentiation were evaluated in vitro. The underlying molecular mechanisms were detected using quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence techniques. An ovariectomized rat osteoporosis model was used to assess the bone-protective effects of aspirin in vivo. RESULTS: Aspirin dose-dependently suppressed RANKL-induced osteoclasts differentiation and bone resorption in vitro and reduced the expression of osteoclastic marker genes, including TRAP, cathepsin K, and CTR. Further molecular analysis revealed that aspirin impaired the RANKL-induced NF-κB and MAPK signaling pathways and prevented the nuclear translocation of the NF-κB p65 subunit. Low-dose aspirin promoted osteogenic differentiation, whereas these effects were attenuated when high-dose aspirin was administered. Both low and high doses of aspirin prevented bone loss in an ovariectomized rat osteoporosis model in vivo. CONCLUSION: Aspirin inhibits RANKL-induced osteoclastogenesis and promotes osteogenesis in a dual regulatory manner, thus preventing bone loss in vivo. These data indicate that aspirin has potential applications in the prevention and treatment of osteopenia.

CCL3 in the bone marrow microenvironment causes bone loss and bone marrow adiposity in aged mice.

The central physiological role of the bone marrow renders bone marrow stromal cells (BMSCs) particularly sensitive to aging. With bone aging, BMSCs acquire a differentiation potential bias in favor of adipogenesis over osteogenesis, and the underlying molecular mechanisms remain unclear. Herein, we investigated the factors underlying age-related changes in the bone marrow and their roles in BMSCs' differentiation. Antibody array revealed that CC chemokine ligand 3 (CCL3) accumulation occurred in the serum of naturally aged mice along with bone aging phenotypes, including bone loss, bone marrow adiposity, and imbalanced BMSC differentiation. In vivo Ccl3 deletion could rescue these phenotypes in aged mice. CCL3 improved the adipogenic differentiation potential of BMSCs, with a positive feedback loop between CCL3 and C/EBPα. CCL3 activated C/EBPα expression via STAT3, while C/EBPα activated CCL3 expression through direct promoter binding, facilitated by DNA hypomethylation. Moreover, CCL3 inhibited BMSCs' osteogenic differentiation potential by blocking ß-catenin activity mediated by ERK-activated Dickkopf-related protein 1 upregulation. Blocking CCL3 in vivo via neutralizing antibodies ameliorated trabecular bone loss and bone marrow adiposity in aged mice. This study provides insights regarding age-related bone loss and bone marrow adiposity pathogenesis and lays a foundation for the identification of new targets for senile osteoporosis treatment.

Use of a Gigli Saw as a Substitute Osteotomy Tool When Oscillating Saw Malfunctions Occur During Hip Arthroplasty.

OBJECTIVE: The oscillating saw has some inherent disadvantages, such as notch formation and blood splash. The objective is to introduce the Gigli saw as a substitute osteotomy tool when oscillating saw malfunctions occur during surgery. METHODS: During our retrospective study, 120 patients (120 hips) who underwent primary total hip arthroplasty (THA) because of femoral neck fracture, femoral head necrosis, developmental hip dysplasia (Crowe I), or primary osteoarthritis between October 2017 and April 2020 at our institute were included. Sixty patients (26 men and 34 women) with a mean age of 67.3 years (±15.1 years) underwent femoral neck osteotomy using a Gigli saw. The other 60 patients (32 men and 28 women) with a mean age of 64.4 years (±18.8 years) underwent femoral neck osteotomy using an oscillating saw. Intraoperative evaluations, including osteotomy time, osteotomy height, number of notch formations, and blood splash generation, were performed. Routine anteroposterior views of the pelvis and proximal femur were obtained for all patients after surgery. RESULTS: The mean osteotomy times were 26.60 ± 14.80 s and 31.80 ± 14.20 s with the oscillating saw and Gigli saw, respectively (t = 1.964, P = 0.0519). The mean osteotomy heights were 1.26 ± 0.22 cm and 1.20 ± 0.14 cm with the oscillating saw and Gigli saw, respectively (t = 1.782, P = 0.0773). The use of a Gigli saw did not result in bone notch formation or blood splash generation when multiple blood splashes were generated in the oscillating saw group. Postoperative radiographs showed no prostheses malposition in the Gigli saw and oscillating saw groups. CONCLUSION: The Gigli saw has various advantages and can be a substitute tool for femoral neck osteotomy during THA when oscillating saw malfunctions occur.

Analysis of related factors of long-term complications after vascularized fibular transplantation.

OBJECTIVES: Free fibula flap is the first choice for jaw reconstruction in head and neck oncology, but postoperative complications in donor site are ignored always. The main purpose of this study was to investigate the long-term complications and potential risk factors of donor site after vascularized fibular transplantation, and to explore the precautions of preparing vascularized fibular flap and the measures of preventing donor site complications. MATERIALS AND METHODS: Data were retrospectively collected on 31 patients who had undergone immediate mandibular reconstruction with a fibular flap after segmental mandibulectomy from 2013 to 2018 in Shanghai Ninth People's Hospital. Thirty-one patients (24 male, 7 female) were available for the long-term complications in donor site analysis from 25 to 96 months after surgery. The data were collected and analyzed, including age at time of operation, early postoperative complications, incidence of dorsiflexion weakness of hallux, donor site missing fibula length, proximal and distal stump fibula length, and subjective evaluation of foot function (AOFAS-hallux, AOFAS-ankle hindfoot, Enneking lower limb function score). In the single-factor analysis in this study, the correlation between related factors and long-term complications was statistically analyzed. For inter-group comparisons of quantitative data, if the normal distribution was satisfied, two independent sample t-tests were used; p < 0.05 was statistical significant. If the normal distribution was not satisfied, Wilcoxon rank-sum test was used, and p < 0.05 was considered statistically significant. For qualitative data, the Fisher exact probability method was compared between group differences, and p < 0.05 was statistically significant. RESULTS: The most commonly encountered complication in our series was dorsiflexion disorder, flexion deformity, numbness of the lateral side of the lower leg, and dorsum of the foot. Ten patients (32.26%) developed hallux flexion deformity after operation, 17 patients (54.84%) had hallux dorsiflexion dysfunction after operation, and 10 patients (32.26%) had numbness of the lateral side of the lower leg and dorsum of the foot. The incidence of hallux dorsiflexion dysfunction, thumb flexion deformity, and sensory disturbance was higher than that of other long-term complications in the donor area. The residual length of fibular distal was related to the dorsiflexion dysfunction and flexion deformity of hallux (p < 0.05). The early complications of donor site were correlated with the hallux dorsiflexion dysfunction (p < 0.05). CONCLUSIONS: The incidence of dorsiflexion disorder and flexion deformity is higher in patients after fibula transplantation. The less the residual length of fibular distal, the more obvious the long-term complications in the donor site, and the higher the incidence of dorsiflexion dysfunction and flexion deformity of hallux. CLINICAL RELEVANCE: The long-term complications of donor site after fibular transplantation seriously affect the quality of life of patients and provide clinical reference for further reducing the occurrence of donor site complications.

Fusion of multimodality image and point cloud for spatial surface registration for knee arthroplasty.

BACKGROUND: Image-guided computer-aided navigation system is an indispensable part of computer assisted orthopaedic surgery. However, the location and number of fiducial markers, the time required to localise fiducial markers in existing systems affect their effectiveness. METHOD: The study proposed that spatial surface registration between the point cloud on the surface of the fusion model based on preoperative knee MRI and CT images and the point cloud on the cartilage surface captured by intraoperative laser scanner could solve the above limitations. RESULTS: The experimental results show that the registration error of the method is less than 2 mm, but the total time from scanning the point cloud on patient's cartilage surface to registering it with the point cloud in preoperative image space is less than 2 min. CONCLUSION: The method achieves the registration accuracy similar to existing methods without selecting anatomical corresponding points, which is of great help to the clinic.

Application of a novel osteotomy instrumentation as a substitute tool in total hip arthroplasty.

BACKGROUND: Mechanical failure, power shortage, and inadvertent contamination of the oscillating saw occasionally occurs in actualizing femoral neck osteotomy during total hip arthroplasty (THA); however, no appropriate alternative solution is currently available. This study aimed to introduce a novel osteotomy instrumentation (fretsaw, jig, cable passer hook) as a substitute tool while the oscillating saw was unavailable during THA. METHODS: This study included 40 patients (40 hips) who underwent femoral neck osteotomy during primary THA using the new osteotomy instrumentation (n = 20) and the oscillating saw (n = 20). Clinical data and intraoperative findings of all patients were evaluated. RESULTS: The mean osteotomy time was 22.3 ± 3.1 s (range, 17-30 s) and 29.4 ± 3.7 s (range, 25-39 s) in the oscillating saw group and in the new osteotomy instrumentation group, respectively (P < 0.001). The Harris Hip Score (HHS) improved in both groups; the mean HSS was 82.3 ± 2.5 and 83.3 ± 3.5 in the oscillating saw group and new osteotomy instrumentation group at 6 months after surgery, respectively (P = 0.297). CONCLUSIONS: The original osteotomy instrumentation can be an ideal substitute tool for femoral neck osteotomy in THA, especially when the oscillating saw is unavailable or malfunctioning.

Favorable osteogenic activity of iron doped in silicocarnotite bioceramic: In vitro and in vivo Studies.

BACKGROUND: Calcium phosphate silicate (Ca5(PO4)2SiO4 or CPS) is a promising bioceramic for bone grafting. Iron (Fe) is a trace element in the human body that has been reported to enhance the mechanical strength of CPS ceramics. However, the exact biofunctions of Fe, combined with another human trace element, viz. silicon (Si), in CPS and the optimal dose for Fe addition must be further investigated. METHODS: In vitro: the morphology, structure and cell adhesion were observed by SEM; the ability to promote osteogenic differentiation and mineralization was explored by ALP and alizarin red staining; the expression of osteogenic-specific genes and proteins was detected by PCR, WB and immunofluorescence. In vivo: Further exploration of bone regeneration capacity by establishing a skull defect model. RESULTS: In vitro, we observed increased content of adhesion-related proteins and osteogenic-related genes expression of Fe-CPS compared with CPS, as demonstrated by immunofluorescence and polymerase chain reaction experiments, respectively. In vivo micro-computed tomography images, histomorphology, and undecalcified bone slicing also showed improved osteogenic ability of Fe-CPS bioceramics. CONCLUSION: With the addition of Fe2O3, the new bone formation rate of the Fe-CPS scaffold after 12 weeks increased from 9.42% to 43.76%. Moreover, both in vitro and in vivo experimental outcomes indicated that Fe addition improved the CPS bioceramics in terms of their osteogenic ability by promoting the expression of osteogenic-related genes. Fe-CPS bioceramics can be employed as a novel material for bone tissue engineering on account of their outstanding new bone formation ability. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: This study suggests that Fe-CPS bioceramics can be employed as a novel material for bone tissue engineering on account of their outstanding new bone formation ability,which provides promising therapeutic implants and strategies for the treatment of large segmental bone defects.

Positive Correlation Between the Femur Neck Shaft and Anteversion Angles: A Retrospective Computed Tomography Analysis in Patients With Developmental Dysplasia of the Hip.

BACKGROUND: This study aimed to explore the anatomical correlation between the femoral neck shaft angle (NSA) and femoral anteversion angle (AA) in patients with developmental dysplasia of the hip based on the Crowe classification and provide a novel method to estimate the femoral AA on anteroposterior pelvic radiographs. METHODS: A total of 208 patients with dysplastic hips who underwent total hip arthroplasty at our institution were retrospectively included. Preoperative physiological AA and NSA were determined via 3-dimensional computed tomography. Linear regressions and Pearson's coefficients were calculated to assess the correlation between the femoral NSA and femoral AA. RESULTS: A total of 416 hips were divided into 5 subgroups: 99 normal, 143 type I, 71 type II, 63 type III, and 40 type IV hips following the Crowe classification. Dysplastic femurs had significantly higher AAs than normal hips (25.2° vs 31.4° vs 33.3° vs 35.5° vs 41.7°). Significant positive correlations between the AA and NSA were observed in normal (r = 0.635), type I (r = 0.700), type II (r = 0.612), and type III (r = 0.638) hips (P < .001); however, no meaningful correlation was observed in type IV hips (r = 0.218, P = .176). CONCLUSION: The NSA and AA correlated positively and significantly in the normal and dysplastic Crowe type I-III hips. The relationship between the NSA and AA indicates torsion of the proximal femur and offers an opportunity for straightforward estimation of AA based on NSA.

The effect of enhanced bone marrow in conjunction with 3D-printed PLA-HA in the repair of critical-sized bone defects in a rabbit model.

BACKGROUND: Traditionally, the iliac crest has been the most common harvesting site for autologous bone grafts; however, it has some limitations, including poor bone availability and donor-site morbidity. This study sought to explore the effect of enhanced bone marrow (eBM) in conjunction with three-dimensional (3D)-printed polylactide-hydroxyapatite (PLA-HA) scaffolds in the repair of critical-sized bone defects in a rabbit model. METHODS: First, 3D-printed PLA-HA scaffolds were fabricated and evaluated using micro-computed tomography (µCT) and scanning electron microscopy (SEM). Twenty-seven New Zealand white rabbits were randomly divided into 3 groups (n=9 per group), and the defects were treated using 3D-printed PLA-HA scaffolds (the PLA-HA group) or eBM in conjunction with 3D-printed PLA-HA scaffolds (the PLA-HA/eBM group), or were left untreated (the control group). Radiographic, µCT, and histological analyses were performed to evaluate bone regeneration in the different groups. RESULTS: The 3D-printed PLA-HA scaffolds were cylindrical, and had a mean pore size of 500±47.1 µm and 60%±3.5% porosity. At 4 and 8 weeks, the lane-sandhu X-ray score in the PLA-HA/eBM group was significantly higher than that in the PLA-HA group and the control group (P<0.01). At 8 weeks, the µCT analysis showed that the bone volume (BV) and bone volume/tissue volume (BV/TV) in the PLA-HA/eBM group were significantly higher than those in the PLA-HA group and the control group (P<0.01). Hematoxylin and eosin staining indicated that the new bone area in the PLA-HA/eBM group was significantly higher than that in the PLA-HA group and the control group (P<0.01). CONCLUSIONS: The group that was treated with eBM in conjunction with 3D-printed PLA-HA showed enhanced bone repair compared to the other 2 groups. PLA-HA/eBM scaffolds represent a promising way to treat critical-sized bone defects.

Comparison of 3D Printing Rapid Prototyping Technology with Traditional Radiographs in Evaluating Acetabular Defects in Revision Hip Arthroplasty: A Prospective and Consecutive Study.

OBJECTIVE: To compare rapid prototyping technology (RP tech) in revision total hip arthroplasty (RTHA) with traditional examination methods and to see how they are different in evaluating acetabular anatomy and designing surgical procedure. METHODS: From February 2014 to March 2018, 43 RTHA patients with complex acetabulum defects were enrolled in this prospective study regardless of age or gender. Incomplete and unclear data were excluded. Three types of radiographic examination were performed on each patient before the revision surgery. Four groups of evaluations were designed: (i) X-ray; (ii) computed tomography (CT-scan); (iii) RP tech; and (iv) CT-aided RP tech. Discrepancies between preoperative radiographic analysis and intra-operative findings were separately compared by a team of surgeons. Premade surgical plans based on each evaluation method were compared with the final surgical procedure. The compliance of anatomic evaluation and surgical plan-design based on 3D RP tech and traditional radiographs were ranked manually by a of team surgeons into: (i) complete accordance; (ii) general accordance; and (iii) undetermined structure/procedure. The difference in ranks between RP tech and traditional radiographic methods were analyzed with a nonparametric Kruskal-Wallis test. P < 0.05 was considered significant. Multiple adjustments were taken for the statistical tests level according to the Bonferroni method. RESULTS: For anatomic analysis, the accordance in four groups of evaluating methods differed from each other (P < 0.05) except for the comparison of RP tech and CT-aided RP tech. RP tech displayed better anatomic evaluating accuracy than traditional methods (X-ray and CT) with the "complete accordance" rates of these groups being 88.37%, 4.65% and 27.91%, respectively. But CT-aided RP tech did not improve accuracy significantly compared with using RP tech individually, although the value seems high in the CT-aided RP group with the "complete accordance" rate of 95.35%. For surgery design, RP tech significantly showed better applicable surgical design compared with X-ray and CT (P < 0.05), and the "complete accordance" rates were 88.37%, 6.98% and 23.26%, but no significant difference was observed between RP tech and CT-aided RP tech, and the "complete accordance" rate of CT-aided RP tech group was 97.67%. RP tech showed remarkable improvement in bone defect assessment and surgical plan design. CONCLUSION: Using RP technology improved both sensibility and accuracy in acetabular defect evaluation with better locating and evaluating efficiency compared with X-ray and CT-scans. It also improved surgical schedule designing in complex acetabular defecting revision surgery. In particularly complex cases, CT aided RP tech may increase the accuracy of RP tech.

Verification and clinical translation of a newly designed "Skywalker" robot for total knee arthroplasty: A prospective clinical study.

OBJECTIVE: To evaluate accuracy of an innovative "Skywalker" system, a newly designed, robot-assisted operation system for orthopaedics via a clinical trial at knee joint. METHODS: We conducted a prospective analysis of the clinical data of 31 patients who underwent total knee arthroplasty assisted by the "Skywalker" robot (Microport, Suzhou, China) from June 2020 to January 2021. Five male patients and 26 female patients aged 69.68 â€‹± â€‹6.11 years (range: 57-79 years) were diagnosed with knee osteoarthritis and indicated for surgery. The "Skywalker" surgical robotic system was adopted to make a preoperative plan for knee arthroplasty. When the robotic arm reached the specified position during the operation, a single surgeon performed the osteotomy with a cutting saw through the cutting jig, and the difference between the actual and the expected resection thickness, and the preoperative and postoperative lower limb alignments were measured. RESULTS: The actual error of the resection thickness was the difference between the actual and the expected resection thickness. The absolute error of the resection thickness was the absolute value of the actual error of resection thickness. The absolute errors of the resection thickness of the medial and lateral condyle of the distal femur, the medial and lateral posterior condyle of the femur, and the medial and lateral sides of the tibial plateau were 0.87 â€‹± â€‹0.63 â€‹mm, 1.02 â€‹± â€‹0.67 â€‹mm, 0.74 â€‹± â€‹0.46 â€‹mm, 0.98 â€‹± â€‹0.81 â€‹mm, 0.92 â€‹± â€‹0.66 â€‹mm, and 1.04 â€‹± â€‹0.84 â€‹mm, respectively. The absolute angle errors between the actual postoperative angles and the preoperative planned angles of the lower limb alignment angles, coronal femoral component angles, and coronal tibial component angles were 1.46° â€‹± â€‹0.95°, 1.13° â€‹± â€‹1.01°, and 1.05° â€‹± â€‹0.73°, respectively. Besides, 100% of the absolute error of the HKA angles was within 3°. In addition, compared to the preoperative lower limb alignment angle, 90.32% of the postoperative lower limb alignment angles of 31 patients were closer to 180° after the operation. All 31 patients underwent a successful surgery, and no relevant complications occurred after the operation, such as surgical site infection, deep venous thrombosis, or vascular and nerve injury. CONCLUSION: The "Skywalker" system has good osteotomy accuracy, can achieve the planned angles well, and is expected to assist surgeons in performing accurate bone cuts and reconstructing planned lower limb alignments in the relevant clinical applications in future.

Exposure to high levels of magnesium disrupts bone mineralization in vitro and in vivo.

BACKGROUND: The removal of permanent internal fixation devices by secondary surgery could be avoided if these devices were made of degradable magnesium and magnesium alloys. Before such implants can be used clinically, however, the biological effect of magnesium exposure on surrounding bone must be evaluated. Previous studies have focused on bone formation; few have examined the effects of magnesium on the bone quality that affect many biomechanical properties. METHODS: Using bone quality parameters, we analyzed in vivo changes in bone properties and biomechanics after exposure to locally high levels of magnesium. RESULTS: Local bone mineralization was significantly disrupted following exposure to a porous rod of pure magnesium. Normal crystal formation and crystallinity were inhibited and the mineral-to-matrix ratio decreased. These results were consistent with those of in vitro experiments, in which high levels of magnesium inhibited mineral deposition by mesenchymal stem cells (MSCs) but increased alkaline phosphatase (ALP) expression. The same mineralization inhibition was observed around magnesium implants via micro-computerized tomography (micro-CT) and von Kossa staining. Such reduced bone quality around degrading magnesium rods could negatively impact bone biomechanics. CONCLUSIONS: This study showed that exposure to the local high magnesium levels that arise from rapidly degrading magnesium devices may significantly disrupt bone mineralization and negatively impact bone biomechanics.

The effect of induced membranes combined with enhanced bone marrow and 3D PLA-HA on repairing long bone defects in vivo.

The repair of large bone defects has always been a challenge, especially with respect to regeneration capacity and autogenous bone availability. To address this problem, we fabricated a 3D-printed polylactic acid (PLA) and hydroxyapatite (HA) scaffold (3D-printed PLA-HA, providing scaffold) loaded with enhanced bone marrow (eBM, providing seed cells) combined with induced membrane (IM, providing grow factors) to repair large radial defects in rabbits. in vitro assays, we demonstrated that 3D-printed PLA-HA had excellent biocompatibility, as shown by co-culturing with mesenchymal stem cells (MSCs); eBM-derived MSCs exhibited considerable differentiation potential, as shown in trilineage differentiation assays. To investigate bone formation efficacy in vivo, the rabbit radial long bone defect model was established. In the first stage, polymethylmethacrylate (PMMA) was inserted into the bone defect to stimulate the formation of IM; in the second stage, iliac crest bone graft (ICBG) with IM, PLA-HA alone with the removal of IM, PLA-HA with IM, and PLA-HA in conjunction with IM and eBM were sequentially applied to repair the long bone defect. At 8, 12, and 16 weeks, X-ray plain radiography, microcomputed tomography, and histological analysis were performed to evaluate the efficacy of bone repair and bone regeneration in each group. We found that IM combined with PLA-HA and eBM prominently enhanced bone repair and reconstruction, equivalent to that of IM/ICBG. Taken together, the data suggest that PLA-HA loaded with eBM combined with IM can be an alternative to IM with bone autografts for the treatment of large bone defects.

Optimal Level of Femoral Neck for Predicting Postoperative Stem Anteversion in Total Hip Arthroplasty for Crowe Type I Dysplastic Hip.

OBJECTIVE: This study aimed to investigate the optimal level of femoral neck for measuring femoral anteversion to predict postoperative stem anteversion in Crowe type I developmental dysplasia of the hip. METHODS: This retrospective study analyzed 108 Crowe type I hips that underwent THA between January 2016 and December 2017, including 70 women and 19 men with a mean age of 63.08 ± 9.13 (range, 41-83) years. The single-wedge stem was used in 37 hips, the double-wedge stem was used in 71 hips. Computed tomography scans were performed pre- and post-operation. Femoral anteversion at six levels of the proximal femur were measured via preoperative two-dimensional computed tomography. Femoral anteversion at the level of the femoral neck osteotomy plane and postoperative stem anteversion were measured via three-dimensional reconstructed models. RESULTS: The mean follow-up period was 18.5 months (range, 12-27). The mean preoperative Harris Hip Score was 51.5 ± 8.7 and improved to 90.4 ± 7.8 (P < 0.001) by the last follow-up. There were no intraoperative fractures, and no infections occurred during the follow-up period. Two patients developed deep venous thrombosis. There was no sign of prosthetic loosening in all hips. No significant correlations were found between the height of the femoral neck osteotomy plane and postoperative stem anteversion (r = -0.119, P = 0.220). Femoral anteversion decreased gradually from 64.00° ± 10.51° at the center of lesser trochanter to 15.21° ± 13.31° at the head-neck junction, which was changed from more to less than stem anteversion (24.37° ± 13.86°). The femoral anteversion at femoral head-neck junction (15.21° ± 13.31°) was significantly less than postoperative stem anteversion (P = 0.000), with a difference of -9.16° ± 9.27°. The femoral anteversion at the level of the osteotomy plane (28.48° ± 15.34°) was significantly more than the postoperative stem anteversion (P = 0.000), with a difference of 4.11° ± 9.56°. Among all six levels and the level of osteotomy, femoral anteversion at the 10-mm level above the proximal base of lesser trochanter (22.65 ± 12.92) displayed the smallest difference (-1.72° ± 8.90°) and a good correlation (r = 0.764) with postoperative stem anteversion for all 108 hips, with a moderate correlation of 0.465 for single-wedge stem hips and an excellent correlation of 0.821 for double-wedge stem hips. CONCLUSION: For Crowe type I hips, femoral anteversion would be different if it was measured via different levels of the femoral neck. The 10-mm level above the proximal base of the lesser trochanter could be an optimum choice for measuring femoral anteversion to predict postoperative stem anteversion.

Author Correction: Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of mice.

During re-read of our previously article Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of micepublished in Acta Pharmacologica Sinica, we were regretted to point out a mistake shown in Fig. 2a. The representative figure chosen to indicate the inhibitory effect of 4 mg/kg of plumbagin treatment at 1 week against MDA-MB-231SArfp cells localization within bone environment was incorrect due to the mishandling in manuscript preparation. Although this correction does not affect the results and conclusion of the paper, all the authors agree on the correction of our negligence as providing the corrected Fig. 2a presented below. We feel sorry and apologize for all the inconvenience it caused.An amendment to this paper has been published and can be accessed via a link at the top of the paper.

LncRNA expression profiles and the negative regulation of lncRNA-NOMMUT037835.2 in osteoclastogenesis.

Bone is a rigid and dynamic organ that continuously undergoes remodeling and repair. The balance between osteoblastic bone formation and osteoclastic bone resorption is essential for normal bone homeostasis. Osteoclasts are giant multinucleated cells derived from the monocyte/macrophage hematopoietic lineage and are regulated by various cytokines. Long non-coding (lnc) RNAs are known to regulate many biological processes in the skeletal system in both normal and diseased states; however, the lncRNA-mediated regulation of osteoclastogenesis has not been extensively studied. Hence, in the present study, we performed microarray analysis of lncRNAs expressed during different stages of osteoclast differentiation and fusion. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed the biological functions of target genes of lncRNAs that were specifically up- or downregulated at the different stages. Microarray and bioinformatic prediction results were used to generate co-expression networks of lncRNAs-mRNAs and lncRNAs-transcription factors. Based on the analysis, we identified one lncRNA, NONMMUT037835.2, which plays an important role during osteoclastogenesis. Upregulation of lncRNA-NONMMUT037835.2 inhibited osteoclastic differentiation, whereas downregulation of lncRNA-NONMMUT037835.2 promoted osteoclast formation and fusion. Our study also indicated that lncRNA-NOMMUT037835.2 might regulated osteoclastogenesis through negatively regulating RANK expression and inhibiting NF-κB/MAPK signaling pathway. Our results lead to a better understanding of the molecular mechanisms and provided a theoretical basis for developing therapeutic agents for diseases related to dysregulation of bone homeostasis.

Correction: Hypericin targets osteoclast and prevents breast cancer-induced bone metastasis via NFATc1 signaling pathway.

[This corrects the article DOI: 10.18632/oncotarget.22930.].

Clinical Applications of 3-Dimensional Printing Technology in Hip Joint.

Three-dimensional (3D) printing is a digital rapid prototyping technology based on a discrete and heap-forming principle. We identified 53 articles from PubMed by searching "Hip" and "Printing, Three-Dimensional"; 52 of the articles were published from 2015 onwards and were, therefore, initially considered and discussed. Clinical application of the 3D printing technique in the hip joint mainly includes three aspects: a 3D-printed bony 1:1 scale model, a custom prosthesis, and patient-specific instruments (PSI). Compared with 2-dimensional image, the shape of bone can be obtained more directly from a 1:1 scale model, which may be beneficial for preoperative evaluation and surgical planning. Custom prostheses can be devised on the basis of radiological images, to not only eliminate the fissure between the prosthesis and the patient's bone but also potentially resulting in the 3D-printed prosthesis functioning better. As an alternative support to intraoperative computer navigation, PSI can anchor to a specially appointed position on the patient's bone to make accurate bone cuts during surgery following a precise design preoperatively. The 3D printing technique could improve the surgeon's efficiency in the operating room, shorten operative times, and reduce exposure to radiation. Well known for its customization, 3D printing technology presents new potential for treating complex hip joint disease.

Correction to: Suppressive effects of plumbagin on invasion and migration of breast cancer cells via the inhibition of STAT3 signaling and down-regulation of inflammatory cytokine expressions.

[This corrects the article DOI: 10.4248/BR201304007.].