Effective regeneration of rat sciatic nerve using nanofibrous scaffolds containing rat ADSCs with controlled release of rhNGF and melatonin molecules for the treatment of peripheral injury model.

Different therapeutic strategies have been designed and developed for the repair and regeneration of peripheral nerve injury (PNI) tissue as a result of advancements in tissue engineering and regenerative medicine. Due to its versatility, controlled delivery and administration of multifunctional therapeutic agents can be regarded of as an effective strategy in treating nerve injury. In this study, melatonin (Mel) molecules and recombinant human nerve growth factor (rhNGF) were loaded on the surface and in the core of polycaprolactone/chitosan (PCL/CS) blended nanofibrous scaffold. To simulate the in vivo microenvironment, a dual-delivery three-dimensional (3-D) nanofibrous matrix was developed and the in vitro neural development of stem cell differentiation process was systematically examined. The microscopic technique with acridine orange and ethidium bromide (AO/EB) fluorescence staining method was used to establish the adipose-derived stem cells (ADSCs) differentiation and cell-cell communications, which demonstrated that the effective differentiation of the ADSCs with nanofibrous matrix. As investigated observations, ADSCs differentiation was further evident through cell migration assay and gene expression analysis. According to the biocompatibility analysis, the nanofibrous matrix did not trigger any adverse immunological reactions. Based on these characteristics, a 5-week in vivo investigation examined the potential of the developed nanofibrous matrix in the regeneration of sciatic nerve of rats. Additionally, compared to the negative control group, the electrophysiological and walking track analyses demonstrated improved sciatic nerve regeneration. This study demonstrates the nanofibrous matrix's ability to regenerate peripheral nerves.

Facile construction of calcium titanate-loaded silk fibroin scaffolds hybrid frameworks for accelerating neuronal cell growth in peripheral nerve regeneration.

Different concentrations of calcium titanate (CaTiO3) nanoparticles were loaded into the Silk fibroin (SF) solution to construct porous SF@CaTiO3 hybrid scaffolds, which were shown to have enhanced properties for stimulating peripheral nerve regeneration. Surface charges, crystallization intensity, wettability, porosity, and morphology were measured and analyzed. We analyzed the hybrid porous SF@CaTiO3 scaffolds that affected the expansion of Schwann cells. The results demonstrated a concentration-dependent influence on the dispersion of nanoparticles in the CaTiO3 hybridized SF scaffolds. Incorporating CaTiO3-NPs into the porous SF@CaTiO3 hybrid scaffolds can boost hydrophobicity while decreasing surface charge density and porosity. The hybridized scaffolds mostly had an orthorhombic calcium titanate crystal structure with amorphous Silk fibroin mixed. Schwann cell cultures revealed that SF@CaTiO3 hybrid scaffolds containing an optimal CaTiO3-NPs concentration could stimulate the proliferation, attachment, and protection of Schwann cell biological functions, suggesting the scaffolds' potential for use in peripheral nerve regeneration.

[Comparison of effect between internal fixation and total hip replacement in the treatment of displaced femoral neck fracture in middle age patients].

OBJECTIVE: To analyze and compare the clinical efficacy of internal fixation and total hip replacement in the treatment of displaced femoral neck fracture from 55 to 65 years. METHODS: From September 2016 to August 2020, 86 patients with Garden type Ⅲ or Ⅳ femoral neck fracture were divided into two groups according to different surgical methods. Among them, 38 patients were treated with lag screws for internal fixation, there were 26 males and 12 females, aged 55 to 64 years old with an average of(60.2±3.1) years;the other 48 patients were treated with total hip replacement, including 28 males and 20 females, aged from 57 to 65 years old with an average of(61.3±3.8) years. The time from injury to operation ranged from 1 to 3 days. The reoperation rate, incidence of deep infection, Harris score of hip joint function, visual analogue scale(VAS) of pain and patients reported outcome scores(European five-dimensional Health Questionnaire, EQ-5D) were compared between two groups. RESULTS: All patients were followed up for 24 to 54 months with an average of (35.8±10.3) months. There was significant difference in reoperation rate between two groups (P<0.05). There was no significant difference on the incidence of deep infection, hip Harris score and VAS between two groups(P>0.05) . The postoperative EQ-5D score of patients with internal fixation was lower than that of total hip replacement, and the difference was statistically significant(P<0.05). CONCLUSION: Both the surgery of internal fixation and total hip replacement have similar effect in short-and medium term among the patients aged 55 to 65 years old. However, for the reoperation rate, the group of internal fixation was higher than that of total hip replacement. For the subjective functional score of patients, the group of internal fixation was lower than that of total hip replacement.

Investigation of femoral condyle height changes during flexion of the knee: implication to gap balance in TKA surgery.

BACKGROUND: Gap balance of the knee at 0° and 90° of flexion has been pursued in total knee arthroplasty (TKA) with the trans-epicondyle axis (TEA) as a reference. This study investigated the height changes of the tibiofemoral articulation and compared the data with the femoral condyle height changes measured using different flexion axes. MATERIALS AND METHODS: Twenty healthy knees were investigated during an in vivo weightbearing flexion using a technique combining MRI and a dual fluoroscopic imaging system (DFIS). The tibiofemoral contact points and the femoral condyle heights [measured using: TEA, geometric center axis (GCA), and iso-height axis (IHA)] were determined at each flexion angle. The height changes of the articular contact points and the femoral condyles were compared along the flexion path. RESULTS: The changes of the medial and lateral contact point heights were within 2.5 mm along the flexion path. The changes of the medial and lateral condyle heights were within 8.9 mm for TEA, within 4.2 mm for GCA and within 3.0 mm for IHA. The height changes measured by the contact points and IHA are similar (p > 0.05), and both are significantly smaller than those measured using the TEA and GCA (p < 0.05). CONCLUSIONS: The TEA and GCA measured varying femoral condyle heights, but the IHA resulted in minimal condyle height changes and could better represent the articulation characteristics of the knee. The data suggested that the IHA could be used as an alternative reference to guide surgical preparation of gap balance along the knee flexion path during TKA surgeries.

circPhc3 sponging microRNA­93­3p is involved in the regulation of chondrocyte function by mechanical instability in osteoarthritis.

Cartilage extracellular matrix (ECM) metabolism disorder caused by mechanical instability is a leading cause of osteoarthritis (OA), but the exact mechanisms have not been fully elucidated. Recent studies have suggested an important role of circular RNAs (circRNAs/circs) in OA. The present study aimed to investigate whether circRNAs might have a role in mechanical instability­regulated chondrocyte matrix metabolism in OA. The expression levels of circPhc3 in human and mouse OA cartilage samples were measured using reverse transcription­quantitative PCR and fluorescence in situ hybridization. The effects of circPhc3 on chondrocyte ECM metabolism were further investigated by overexpressing and knocking down circPhc3 in OA chondrocytes. The downstream target of circPhc3 was examined by performing a luciferase reporter assay. The results showed that the expression of circPhc3 was reduced in human and mouse OA cartilage. Moreover, circPhc3 was involved in mechanical loading­regulated production of ECM and cartilage­degrading enzymes. Further studies showed that circPhc3 regulated chondrocyte matrix metabolism primarily by binding to microRNA (miR)­93­3p, and mechanistic studies found that miR­93­3p targeting of FoxO1 was involved in chondrocyte matrix metabolism. Taken together, these results indicated that circPhc3 may serve an important role in the progression of OA and may be a good target for the treatment of OA.

Physiological articular contact kinematics and morphological femoral condyle translations of the tibiofemoral joint.

The changes of tibiofemoral articular cartilage contact locations during knee activities represent a physiological functional characteristic of the knee. However, most studies reported relative motions of the tibia and femur using morphological flexion axes. Few data have been reported on comparisons of morphological femoral condyle motions and physiological tibiofemoral cartilage contact location changes. This study compared the morphological and physiological kinematic measures of 20 knees during an in vivo weightbearing single leg lunge from full extension to 120° of flexion using a combined MRI and dual fluoroscopic imaging system (DFIS) technique. The morphological femoral condyle motion was measured using three flexion axes: trans-epicondylar axis (TEA), geometric center axis (GCA) and iso-height axis (IHA). At low flexion angles, the medial femoral condyle moved anteriorly, opposite to that of the contact points, and was accompanied with a sharp increase in external femoral condyle rotation. At 120° of flexion, the morphological measures of the lateral femoral condyle were more posteriorly positioned than those of the contact locations. The data showed that the morphological measures of femoral condyle translations and axial rotations varied with different flexion axes and did not represent the physiological articular contact kinematics. Biomechanical evaluations of the knee joint motion should include both morphological and physiological kinematics data to accurately demonstrate the functionality of the knee.

3D Printed Guides and Preoperative Planning for Uncemented Stem Anteversion Reconstruction during Hip Arthroplasty: A Pilot Study.

OBJECTIVE: To investigate if 3D printed guides and preoperative planning can accurately control femoral stem anteversion. METHODS: A prospective comparative study was carried out from 2018 to 2020, including 53 patients who underwent hip arthroplasty for femoral neck fracture. The target rotation center of the femoral head is determined by three-dimensional planning. In group A, planning was made by 2D templates. In group B, preoperative 3D planning and 3D printed osteotomy/positioning guides were performed. After the operation, 3D model registration was performed to calculate the accuracy of anteversion restoration. RESULTS: We screened 60 patients and randomized a total of 53 to 2 parallel study arms: 30 patients to the group A (traditional operation) and 23 patients to the group B (3D preoperative planning and 3D printed guide). There were no significant differences in demographic or perioperative data between study groups. The restoration accuracy of group A was 5.42° ± 3.65° and of group B was 2.32° ± 1.89°. The number and rate of abnormal cases was 15 (50%) and 2 (8.7%), respectively. Significant statistical differences were found in angle change, restoration accuracy, and number of abnormal cases. CONCLUSION: Three-dimensional preoperative planning and 3D printed guides can improve the accuracy of the restoration of femoral anteversion during hip arthroplasty.

There are isoheight points that measure constant femoral condyle heights along the knee flexion path.

PURPOSE: It is a challenge to evaluate the maintenance of medial and lateral soft tissue balance in total knee arthroplasty (TKA). This study aimed to determine the "isoheight" points and the "isoheight" axis (IHA) that can measure constant medial/lateral condyle heights during flexion of the knee, and compare the IHA with two major anatomical axes, the transepicondylar axis (TEA) and the geometric center axis (GCA). METHODS: Twenty-two healthy human knees were imaged using a combined MRI and dual fluoroscopic imaging system while performing a single-legged lunge (0°-120°). The isoheight points of the medial and lateral femoral condyles were defined as the locations with the least amount of changes in heights during the knee flexion; an IHA is the line connecting the medial and lateral isoheight points. The measured changes of the condyle heights using the IHA were compared with those measured using the TEA and GCA. RESULTS: Overall, the IHA was posterior and distal to the TEA, and anterior to the GCA. The isoheight points measured condyle height changes within 1.2 ± 2.3 mm at the medial and 0.7 ± 3.3 mm at the lateral sides during the knee flexion. Between 0° and 45°, the condyle height changes measured using the GCA (medial: 3.0 ± 1.8 mm, lateral: 2.3 ± 2.0 mm) were significantly larger than those of the IHA and the TEA (p < 0.05). Between 90° and 120°, the changes of the condyle heights measured using the TEA (medial: 5.3 ± 1.8 mm, lateral: 3.3 ± 1.8 mm) were significantly larger than those of the IHA and GCA (p < 0.05). CONCLUSION: There are isoheight points in the medial and lateral femoral condyles that can measure constant heights along the full range of knee flexion and could be used to formulate an "isoheight" axis (IHA) of the femur. The condyle height changes measured by the TEA and GCA were greater than the IHA measurements along the flexion path. These data could be used as a valuable reference to evaluate the condyle height changes after TKA surgeries and help achieve soft tissue balance and optimal knee kinematics along the flexion path. LEVEL OF EVIDENCE: IV.

Ulinastatin Promotes Regeneration of Peripheral Nerves After Sciatic Nerve Injury by Targeting let-7 microRNAs and Enhancing NGF Expression.

BACKGROUND: Peripheral nerve injury is characterized as a common clinical problem. Ulinastatin (UTI) is a serine protease inhibitor with many biological activities including anti-inflammatory and antioxidant effects. Nonetheless, it is unknown whether UTI has a protective effect on peripheral nerve injury. METHODS: Thirty rats were divided into the sham operation group, the sciatic nerve injury group (injected with normal saline), and the UTI treatment group (80mg/kg/day for two consecutive weeks). Sciatic nerve function index (SFI) was used to assess the biological functions of the sciatic nerve, and compound muscle action potential (CMAP) was measured by electrophysiology. The expressions of let-7 miRNA members were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Nerve growth factor (NGF), nerve regeneration-related proteins GAP43 and NF200, and myelin formation-related proteins MAG and PMP22 expressions were explored by Western blot. After Schwann cells were transfected with let-7 mimics, pcDNA3.1-NGF, let-7 inhibitors, NGF siRNA and their corresponding controls, 5-ethynyl-2'-deoxyuridine (EdU) assay, and Transwell assays were employed to investigate the proliferation and migration of Schwann cells. H2O2 was utilized to construct oxidative injury to cells, and the contents of MDA, SOD, GSH, and CAT were determined. RESULTS: UTI treatment remarkably increased SFI of the rats and CMAP of sciatic nerve, enhanced nerve regeneration, and myelin regeneration, and raised the production of GAP43, NF200, MAG, and PMP22. Furthermore, it was found that UTI markedly reduced let-7 miRNAs' expressions and increased NGF expression after sciatic nerve injury. The dual-luciferase reporter assay validated that let-7 miRNAs targeted NGF, and functional experiments demonstrated that low expression of let-7 miRNAs and NGF overexpression contributed to Schwann cells' proliferation and migration. Additionally, UTI treatment repressed the oxidative stress regulated by let-7/NGF axis. CONCLUSION: UTI modulates the let-7/NGF axis to inhibit oxidative stress, promote nerve regeneration, and facilitate function recovery after peripheral nerve injury.

In vivo kinematics and ligamentous function of the knee during weight-bearing flexion: an investigation on mid-range flexion of the knee.

PURPOSE: To investigate the in vivo femoral condyle motion and synergistic function of the ACL/PCL along the weight-bearing knee flexion. METHODS: Twenty-two healthy human knees were imaged using a combined MRI and dual fluoroscopic imaging technique during a single-legged lunge (0°-120°). The medial and lateral femoral condyle translation and rotation (measured using geometric center axis-GCA), and the length changes of the ACL/PCL were analyzed at: low (0°-30°), mid-range (30°-90°) and high (90°-120°) flexion of the knee. RESULTS: At low flexion (0°-30°), the strains of the ACL and the posterior-medial bundle of the PCL decreased. The medial condyle showed anterior translation and lateral condyle posterior translation, accompanied with a sharp increase in external GCA rotation (internal tibial rotation). As the knee continued flexion in mid-range (30°-90°), both ACL and PCL were slack (with negative strain values). The medial condyle moved anteriorly before 60° of flexion and then posteriorly, accompanied with a slow increase of GCA rotation. As the knee flexed in high flexion (90°-120°), only the PCL had increasingly strains. Both medial and lateral condyles moved posteriorly with a rather constant GCA rotation. CONCLUSIONS: The ACL and PCL were shown to play a reciprocal and synergistic role during knee flexion. Mid-range reciprocal anterior-posterior femoral translation or laxity corresponds to minimal constraints of the ACL and PCL, and may represent a natural motion character of normal knees. The data could be used as a valuable reference when managing the mid-range "instability" and enhancing high flexion capability of the knee after TKAs. LEVEL OF EVIDENCE: Level IV.

Integrated analysis of key mRNAs and lncRNAs in osteoarthritis.

Osteoarthritis (OA) is the most common type of arthritis, observed mainly in the population aged >65 years. However, the mechanism underlying the development and progression of OA has remained largely elusive. The present study aimed to identify differentially expressed mRNAs and lncRNAs in OA. By analyzing the GSE48556 and GSE82107 datasets, a total of 202 up- and 434 downregulated mRNAs were identified in OA. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that differently expressed genes were mainly involved in regulating antigen processing and presentation, interspecies interaction between organisms, immune response, transcription and signal transduction. In addition, a series of long non-coding (lnc)RNAs were differently expressed in OA. To provide novel data on the molecular mechanisms and functional roles of these lncRNAs in OA, a co-expression analysis was performed, which revealed that the dysregulated lncRNAs were associated with transcription, signal transduction, immune response and cell adhesion. In addition, certain key genes in protein-protein interaction networks were identified. The present study provided useful information for exploring potential candidate biomarkers for the diagnosis and prognosis of OA, as well as novel drug targets.

Protective effects of psoralidin on IL­1ß­induced chondrocyte apoptosis.

Chondrocyte apoptosis serves a key role in the pathogenesis of osteoarthritis. The present study aimed to investigate the protective effects of psoralidin on interleukin (IL)­1ß­induced chondrocyte apoptosis and explore the underlying mechanisms. Chondrocytes were isolated from the articular cartilage of Sprague­Dawley rats and were treated with 10 ng/ml IL­1ß and various doses of psoralidin (5, 10 or 15 µM). The ratio of apoptosis was measured by Annexin V/propidium iodide double­labeling fluorescence­activated cell sorting (FACS) analysis. Caspase­3 and ­9 activity was determined using a quantitative colorimetric assay. Intracellular levels of reactive oxygen species (ROS) were assessed using a dichlorofluorescein diacetate­labeling FACS analysis, and the release of nitric oxide (NO) was measured using the Griess reaction method. In addition, protein expression levels were detected by western blotting. The results of the present study demonstrated that psoralidin may reduce IL­1ß­induced chondrocyte apoptosis. Psoralidin pretreatment also reversed the inhibitory effects of IL­1ß on B­cell lymphoma 2 (Bcl­2) expression, and decreased the IL­1ß­induced expression of Bcl­2­associated X protein, matrix metalloproteinase (MMP)­1 and MMP­13. Furthermore, psoralidin decreased IL­1ß­induced caspase­3 and ­9 activity, NO release, ROS production and nuclear factor (NF)­κB nuclear translocation. In addition, the NF­κB inhibitor pyrriolidine­dithiocarbamate exerted similar effects to psoralidin, thus suggesting that IL­1ß induced proapoptotic effects in rat chondrocytes via an NF­κB­dependent pathway. Since psoralidin could protect chondrocytes from IL­1ß­induced apoptosis and MMP expression, the present results suggested that psoralidin may be considered a drug candidate for the treatment of osteoarthritis.

Peroxiredoxin 4 inhibits IL-1ß-induced chondrocyte apoptosis via PI3K/AKT signaling.

BACKGROUND: Chondrocytes apoptosis induced by reactive oxygen species (ROS) plays a critical role in the pathogenesis of osteoarthritis (OA). Peroxiredoxin 4 (PRDX4), a member of the PRDX family, is essential for removing metabolic free radicals and reducing intracellular ROS. In this study, we sought to investigate the roles of PRDX4 on interleukin 1ß (IL-1ß)-induced chondrocyte apoptosis. METHODS: Primary chondrocytes were isolated from the articular cartilage of Sprague-Dawley rats, infected with PRDX4 overexpressing lentivirus and treated with IL-1ß (10ng/mL). Cell apoptosis and ROS production identified by flow cytometry. Protein expression levels was evaluated by Western blotting analysis. Nitric oxide (NO) production and Caspase-3/9 activation were assessed by the Griess reaction method and colorimetric assay kit, respectively. RESULTS: PRDX4 overexpression in chondrocytes significantly decreased IL-1ß-induced apoptosis. It also reversed the activity of IL-1ß that increased ROS and NO production. PRDX4 overexpression reversed the activity of IL-1ß that reduced the levels of Bcl-2, p-AKT and p-PRAS40, as well as increased Bax levels and Caspase-3/9 activation. More importantly, pre-treated with AKT inhibitor (AZD5363) significantly reduced the protective effects of PRDX4. CONCLUSIONS: Our data demonstrated that the regulatory effects of PRDX4 on IL-1ß-induced chondrocyte apoptosis can be partially attributed to phosphatidylinositol 3-kinase/AKT signaling. These results indicate that PRDX4 might play a protective role in OA cartilage degeneration.

Multi-View Structural Local Subspace Tracking.

In this paper, we propose a multi-view structural local subspace tracking algorithm based on sparse representation. We approximate the optimal state from three views: (1) the template view; (2) the PCA (principal component analysis) basis view; and (3) the target candidate view. Then we propose a unified objective function to integrate these three view problems together. The proposed model not only exploits the intrinsic relationship among target candidates and their local patches, but also takes advantages of both sparse representation and incremental subspace learning. The optimization problem can be well solved by the customized APG (accelerated proximal gradient) methods together with an iteration manner. Then, we propose an alignment-weighting average method to obtain the optimal state of the target. Furthermore, an occlusion detection strategy is proposed to accurately update the model. Both qualitative and quantitative evaluations demonstrate that our tracker outperforms the state-of-the-art trackers in a wide range of tracking scenarios.

Effect of elbow flexion angles on stress distribution of the proximal ulnar and radius bones under a vertical load: measurement using resistance strain gauges.

OBJECTIVES: This study aimed to explore the surface stress at the proximal ends of the ulna and radius at different elbow flexion angles using the resistance strain method. METHODS: Eight fresh adult cadaveric elbows were tested. The forearms were fixed in a neutral position. Axial load increment experiments were conducted at four different elbow flexion angles (0°, 15°, 30°, and 45°). Surface stain was measured at six sites (tip, middle, and base of the coronoid process; back ulnar notch; olecranon; and anterolateral margin of the radial head). RESULTS: With the exception of the ulnar olecranon, the load-stress curves at each measurement site showed an approximately linear relationship under the four working conditions studied. At a vertical load of 500 N, the greatest stress occurred at the middle of the coronoid process when the elbow flexion angles were 0° and 15°. When the flexion angles were 30° and 45°, the greatest stress occurred at the base of the coronoid process. The stress on the radial head was higher than those at the measurement sites of the proximal end of the ulna. CONCLUSION: The resistance strain method for measuring elbow joint surface stress benefits biomechanics research on the elbow joint. Elbow joint surface stress distributions vary according to different elbow flexion angles.

Revision hip arthroplasty as a treatment of Vancouver B3 periprosthetic femoral fractures without bone grafting.

BACKGROUND: It is conventionally considered that bone grafting is mandatory for Vancouver B3 periprosthetic femoral fractures (PFF) although few clinical studies have challenged the concept previously. The aim of the current study was to investigate the radiographic and functional results of Vancouver B3 PFF treated by revision total hip or hemiarthroplasty (HA) in combination with appropriate internal fixation without bone grafting. MATERIALS AND METHODS: 12 patients with Vancouver B3 PFF were treated by revision THA/HA without bone grafting between March 2004 and May 2008. There were nine females and three males, with an average age of 76 years. PFFs were following primary THA/HA in nine patients and following revision THA/HA in three. Postoperative followup was 5.5 years on average (range, 3.5-6.5 years). At the final followup, radiographic results were evaluated with Beals and Tower's criteria and functional outcomes were evaluated using the Merle d'Aubigné scoring system. RESULTS: All fractures healed within an average of 20 weeks (range, 12-28 weeks). There was no significant deformity and shortening of the affected limb and the implant was stable. The average Merle d'Aubigné score was 15.8. Walking ability was regained in 10 patients without additional assistance, while 2 patients had to use crutches. There were 2 patients with numbness of lateral thigh, possibly due to injury to the lateral femoral cutaneous nerve. There were no implant failures, dislocation and refractures. CONCLUSIONS: Revision THA/HA in combination with appropriate internal fixation without bone grafting is a good option for treatment of Vancouver B3 periprosthetic femoral fractures in the elderly.

Clinical value of the Ottawa ankle rules for diagnosis of fractures in acute ankle injuries.

BACKGROUND: The Ottawa ankle rules (OAR) are clinical decision guidelines used to identify whether patients with ankle injuries need to undergo radiography. The OAR have been proven that their application reduces unnecessary radiography. They have nearly perfect sensitivity for identifying clinically significant ankle fractures. OBJECTIVES: The purpose of this study was to assess the applicability of the OAR in China, to examine their accuracy for the diagnosis of fractures in patients with acute ankle sprains, and to assess their clinical utility for the detection of occult fractures. METHODS: In this prospective study, patients with acute ankle injuries were enrolled during a 6-month period. The eligible patients were examined by emergency orthopedic specialists using the OAR, and then underwent ankle radiography. The results of examination using the OAR were compared with the radiographic results to assess the accuracy of the OAR for ankle fractures. Patients with OAR results highly suggestive of fracture, but no evidence of a fracture on radiographs, were advised to undergo 3-dimensional computed tomography (3D-CT). RESULTS: 183 patients with ankle injuries were enrolled in the study and 63 of these injuries involved fractures. The pooled sensitivity, specificity, positive predictive value and negative predictive value of the OAR for detection of fractures of the ankle were 96.8%, 45.8%, 48.4% and 96.5%, respectively. Our results suggest that clinical application of the OAR could decrease unnecessary radiographs by 31.1%. Of the 21 patients with positive OAR results and negative radiographic findings who underwent 3D-CT examination, five had occult fractures of the lateral malleolus. CONCLUSIONS: The OAR are applicable in the Chinese population, and have high sensitivity and modest specificity for the diagnosis of fractures associated with acute ankle injury. They may detect some occult fractures of the malleoli that are not visible on radiographs.

Surgical approach for high-energy posterior tibial plateau fractures.

BACKGROUND: High-energy fractures of posterior tibial plateau always need surgical treatment. Generally, posterior fragments of these fractures could not be exposed and reduced well in conventional anterior approaches. Although a posterolateral/posteromedial approach to manage posterior tibial plateau fractures can achieve satisfactory results, there are few presentations concerning the treatment of these high-energy injuries based on posterior approaches combined with anterior approach if necessary. MATERIALS AND METHODS: Ten cases of posterior tibial plateau fractures from high-energy injuries were retrospectively reviewed and followed up for mean 26.5 months (range 14-45 months). A posterolateral/posteromedial approach was adopted primarily to fix main fragment in posterior tibial plateau, and intraoperative assessment of the stability of knee was done. An anterior approach was added if required. RESULTS: Posterolateral approach was employed in seven cases, posteromedial in three, and additional anteromedial in three, and anterolateral in two cases. The average time to union of all 10 fractures was 3.7 months (range 3-5.5 months). Nine patients had satisfactory articular reduction. The range of motion of the knee averaged 2° of extension to 110.5° of flexion. No patient complained of knee instability. The average postoperative HSS score at the final followup was 92.70. CONCLUSIONS: High-energy fractures of posterior tibial plateau could be well treated based on posterior approaches combined with necessary anterior approach if required.