Concerting magnesium implant degradation facilitates local chemotherapy in tumor-associated bone defect.

Effective management of malignant tumor-induced bone defects remains challenging due to severe systemic side effects, substantial tumor recurrence, and long-lasting bone reconstruction post tumor resection. Magnesium and its alloys have recently emerged in clinics as orthopedics implantable metals but mostly restricted to mechanical devices. Here, by deposition of calcium-based bilayer coating on the surface, a Mg-based composite implant platform is developed with tailored degradation characteristics, simultaneously integrated with chemotherapeutic (Taxol) loading capacity. The delicate modulation of Mg degradation occurring in aqueous environment is observed to play dual roles, not only in eliciting desirable osteoinductivity, but allows for modification of tumor microenvironment (TME) owing to the continuous release of degradation products. Specifically, the sustainable H2 evolution and Ca2+ from the implant is distinguished to cooperate with local Taxol delivery to achieve superior antineoplastic activity through activating Cyt-c pathway to induce mitochondrial dysfunction, which in turn leads to significant tumor-growth inhibition in vivo. In addition, the local chemotherapeutic delivery of the implant minimizes toxicity and side effects, but markedly fosters osteogenesis and bone repair with appropriate structure degradation in rat femoral defect model. Taken together, a promising intraosseous administration strategy with biodegradable Mg-based implants to facilitate tumor-associated bone defect is proposed.

Open reduction and internal fixation of crescent fracture-dislocation: anterior or posterior approach?

INTRODUCTION: To date, the approach that prevails in the open reduction and internal fixation of crescent fracture-dislocations (CFD) remains unknown. This study aimed to compare the outcomes of CFD treated via the anterior or posterior approach. MATERIALS AND METHODS: Data from 64 cases of CFDs openly reduced through an anterior (group A, n = 31) or a posterior (group B, n = 33) approach were retrospectively analyzed. Functional results, reduction quality, residual displacements in the axial and coronal planes, pelvic asymmetry deformity, and correlations between Day's classification were compared. Complications and fracture union were also recorded. All patients were followed up for at least 12 months. RESULTS: The functional scores were similar between the two groups, and all fractures achieved good or excellent reduction postoperatively. In the coronal plane, the excellent/good ratio in group B was higher than in group A. The mean residual displacement in the coronal plane was significantly higher in group A than in group B, with group A showing greater displacement in both planes for Day I fractures and in the coronal plane for Day II fractures. The residual displacement in both planes for Day III fractures was comparable between the groups. The pelvic asymmetry deformity was equal between the two groups and among the different Day's fracture types. CONCLUSIONS: Open reduction and internal fixation of CFDs obtained satisfactory outcomes through an anterior or posterior approach. The posterior approach achieved a better sacroiliac joint reduction. The optimal indication for the posterior approach was a Day I fracture, followed by a Day II fracture. No correlation was found between the surgical approach and reduction quality in Day III fractures.

Comparison of augmentation effects of medial buttress plate versus trochanteric lag screw in the cannulated screw fixation of Pauwels type III femoral neck fractures: A retrospective clinical study.

OBJECTIVE: This study aimed to compare the effects of a medial buttress plate (MBP) or a trochanteric lag screw (TLS) to augment cannulated screws (CSs) in fixing Pauwels type III femoral neck fractures. METHODS: This retrospective study included 58 patients (21 female, 37 male; mean age=46 years; age=19-64 years) treated by CSs for Pauwels type III femoral neck fractures from 2014 to 2017. All the patients were divided into 2 groups based on the internal fixation patterns: the MBP-augmented group (group A, n=26) and the TLS group (group B, n=32). The mean age was 47 (range=24-57) years in group A and 45 (range=19-64) years in group B. The operation time, intraoperative blood loss, reduction quality, Harris score, and postoperative complications were recorded and compared between both groups. RESULTS: All patients were followed up for an average of 44.8 months in group A and 47.3 months in group B (P=.406). No significant difference was noted in reduction quality (P=1.000). However, group A had a longer operation time (100.2 vs. 64.3 minutes, P < .001) and greater intraoperative blood loss (153.1 vs. 30.0 mL, P < .001) than group B. At the final follow-up, the union rate was equal between group A (96.2%) and group B (90.6%) (P=.760). The mean bone union time was 21.6 weeks in group A and 23.6 weeks in group B (P=.431). The delayed union rate was lower in group A (0%) than in group B (15.6%) (P < .001). The incidence of postoperative complications in terms of implant failure (7.7% vs. 28.1%, P=.048) and femoral neck shortening (7.7% vs. 28.1%, P=.048) were lower in group A than in group B. No significant difference was noted in avascular femoral head necrosis (P=1.000) and the Harris score (P=.659) between the 2 groups. CONCLUSION: In the surgical treatment of Pauwels type III femoral neck fractures, medial buttress plating can offer fewer complications but equal avascular femoral head necrosis rate and functional outcome compared to trochanteric screw application. LEVEL OF EVIDENCE: Level III, Therapeutic study.

Intra-articular fragment mapping in associated both-column acetabular fractures.

INTRODUCTION: Associated both-column acetabular fractures (ABC-AF) are complex. A detailed description of the morphology of the articular surface of the acetabulum is not reported. This study was designed to describe the morphology of the intra-articular fragments using a fracture mapping technique to provide reference in more appropriate approach selection in surgical treatment of the fractures. MATERIALS AND METHODS: Three-dimensional reconstruction CT images from 100 cases of ABC-AFs were retrospectively analyzed using Mimics and 3-matic software. The fractured as well as the reduced three-dimensional models were investigated, and the intra-articular fragments were identified. The distribution of the fracture lines of each main fragment and the overlapping lines of all the fragments were verified on the images. RESULTS: The articular surface of ABC-AFS consist of three types of fragments: column fragment (CF), wall fragment (WF) and isolated fragment (IF), with the total number varying from 2 to 6. CF characterized by long fracture lines exited to periphery of innominate bone while the lines of WF were confined to the walls. IF was a free fragment found in the dome and in the quadrilateral plate. The surface was composed only by CFs in 17 cases (17%), by CFs and WFs in 59 cases (59%) and by all fragments in 24 cases (24%). The distribution of the overall fracture lines was a "dumbbell shaped" pattern, starting from the infero-anterior aspect, passing through the junction of the fossa to the anterior lunate surface and extending into the posterior region of the acetabulum. CONCLUSIONS: The articular fragments of ABC-AFs were composed of CFs, WFs and IFs. The junction of the fossa to the anterior lunate surface and the posterior region of the rim were mostly involved. The location of the articular fragments and their connections to the periphery of the innominate may be considered in selection of approaches.

Morphological analysis of the posterior elements of associated both-column acetabular fractures.

BACKGROUND: It is still in dispute as to whether a posterior approach is applied to reduce the posterior fractures of associated both-column acetabular fractures (ABC-AFs). PURPOSE: To analyze the morphological changes in the posterior elements including the posterior column (PC) and/or associated posterior wall (PW) fragments to provide a reference for surgical planning. MATERIAL AND METHODS: The 3D computed tomography (CT) data of 100 cases of ABC-AFs were retrospectively analyzed using Mimics and 3-Matic software. The line distribution of the retroacetabular surface (RAS), the acetabular fossa, and the size of the PW fragments were analyzed. RESULTS: Fracture lines (n = 89) on RAS appeared in three patterns: transverse lines (n = 41) on the cephalic (65.8%) and caudal (29.3%) thirds; oblique lines (n = 34) on the mid-caudal thirds; and multifragmentary lines (n = 14). The lines of the displaced PW fragment (n = 61) were widely distributed in intra- and extra-articular regions. The mean radian of the PW fragments was >90° in 67.2% of cases and involved anteriorly to the vertex in 90.2% of cases. The average fracture span on the RAS was 0.60-1.00 in 63.9% of cases. The mean length of the spike of PW fragments was >20 mm in 80.3% of cases. DISCUSSION: For PC fractures, transverse lines on the cephalic third of RAS indicated a possibility of the anterior approach, while transverse lines on the distal third or oblique and multifragmentary lines suggest the posterior approach. A displaced PW fragment was involved more extensively both intra-and extra-articularly and may be optimally treated via a posterior approach.

Three-dimensional morphological analysis of quadrilateral plate fragments in associated both-column acetabular fractures.

OBJECTIVE: To investigate whether the fracture morphology of quadrilateral plate (QP) fragments is associated with the anterior and posterior columns in associated both-column (ABC) fractures. MATERIALS AND METHODS: Three-dimensional computed tomography data of 100 ABC fractures treated at our hospital from August 2016 to August 2019 were retrospectively analyzed using Mimics and 3-matic software. The distribution of fracture lines was described using the fracture mapping technique. RESULTS: One fragment presented on the QP was confirmed in 88% of the patients. The QP fragments' fracture lines were divided into the anterior oblique (AO), superior posterior oblique (SPO), and mid-posterior oblique (MPO) lines, occurring in 100, 86, and 8 cases, respectively. AO lines were distributed along the arcuate line. SPO lines were continuations of the AO lines, which were distributed to the posterior column from the greater sciatic notch to the lesser sciatic notch. MPO lines were involved in the QP's central area. A simple fracture was found at the proximal AO and SPO lines in 80% and 86% of all displaced fractures, respectively. AO lines distal to the superior rim of the acetabula were confirmed to be comminuted fractures in 32% of all cases. CONCLUSIONS: In ABC fractures, there was only one QP fragment in nearly 90% of all cases. The QP fractures were mainly present in the QP's peripheral area. More than 80% of the fracture patterns on the cephalic side of the QP were simple. The reduction and internal fixation of QP fractures in ABC fractures should be in the cephalic region.

Synergistic Antibacterial Effect of Zinc Oxide Nanoparticles and Polymorphonuclear Neutrophils.

Zinc oxide nanoparticles (ZnONPs) are inorganic nano-biomaterials with excellent antimicrobial properties. However, their effects on the anti-infection ability of the innate immune system remains poorly understood. The aim of the present study was to explore the potential immunomodulatory effects of ZnONPs on the innate immune system, represented by polymorphonuclear leukocytes (PMNs), and determine whether they can act synergistically to resist pathogen infections. In vitro experiment showed that ZnONPs not only exhibit obvious antibacterial activity at biocompatible concentrations but also enhance the antibacterial property of PMNs. In vivo experiments demonstrated the antibacterial effect of ZnONPs, accompanied by more infiltration of subcutaneous immune cells. Further ex vivo and in vitro experiments revealed that ZnONPs enhanced the migration of PMNs, promoted their bacterial phagocytosis efficiency, proinflammatory cytokine (TNF-α, IL-1ß, and IL-6) expression, and reactive oxygen species (ROS) production. In summary, this study revealed potential synergistic effects of ZnONPs on PMNs to resist pathogen infection and the underlying mechanisms. The findings suggest that attempts should be made to fabricate and apply biomaterials in order to maximize their synergy with the innate immune system, thus promoting the host's resistance to pathogen invasion.

In intra-articular distal humeral fractures: Can combined medial-lateral approach gain better outcomes than olecranon osteotomy?

BACKGROUND: This research aimed to evaluate the functional outcomes of intra-articular distal humeral fractures treated through a combined medial-lateral approach and comparing with olecranon osteotomy simultaneously. METHODS: In this study, 62 distal humeral fractures patients were assessed retrospectively. The olecranon osteotomy was used in 30 cases (14 males, 16 females) and combined medial-lateral in 32 cases (15 males, 17 females). The outcomes of function were assessed by the Mayo Elbow Performance Score (MEPS) and the Disabilities of Arm, Shoulder and Hand (DASH) questionnaire score. The follow-up time was 15.4±3.5 months (range 10-24 months) for a combined medial-lateral group and 14.6±2.6 months (range 10-20 months) for olecranon osteotomy. LEVEL OF EVIDENCE: Level, retrospective study. RESULTS: The flexion-extension of elbows was 115.3°±16.1° in the combined medial-lateral group, and the olecranon osteotomy group was 110.1°±15.2°. A significant difference was observed between the two groups for flexion-extension of the elbows (p=0.041). Pronation-supination of the forearms had a significant difference (p=0.025) between the combined medial-lateral group (160.6°±7.2°) and the olecranon osteotomy group (154.1°±9.3°). Mean MEPS, DASH, excellent and good rate and complication rate for combined medial-lateral approaches were 88.6±6.9 points, 9.8±6.6 points, 90.6% and 9.4%, respectively. Significant differences were not noted between the two groups for mean MEPS, DASH scores and excellent and good rate (p=0.594, p=0.505, p=0.934, respectively) except complication rate (p=0.005). CONCLUSION: The combined medial-lateral approach is successful approach in the treatment of intra-articular distal humeral fractures (especially type C1 and C2) that provides better outcomes for the motion of the elbow, bleeding volume in surgery and complications than olecranon osteotomy.

Conservative treatment for clavicle stress fractures following the clavicular hook plate fixation.

We investigated the outcome of conservative treatment and potential causes for clavicle stress fractures following the clavicular hook plate fixation. Six cases of clavicle stress fractures were retrospectively reviewed. All the stress fractures occurred near the medial end of the hook plates. The average interval between the hook plate fixation and the clavicle stress fractures was 28.3 days (range, 18 to 60 days). The mean follow-up was 27 months (range, 15 to 42 months). Fracture union was achieved in all 6 cases. The most proximal screws in the hook plates were found to be eccentric in the clavicular midshaft in 5 cases. At the final follow-up, the average Constant and Murley scores of the operated shoulders were 91.7 (range, 83 to 96). Clavicle stress fractures could be treated conservatively with satisfactory results. Attention should be paid to the position of the most proximal screws in the hook plates.

Surgical Treatment of Intra-Articular Distal Humeral Fractures by using a Combined Medial and Lateral Approach: An Anatomic Study.

OBJECTIVE: To determine the visible size of the distal humeral articular surface by using a novel combined medial-lateral approach as an alternative method of surgical treatment for intra-articular distal humeral fractures. METHODS: In this anatomical study, 12 adult fresh-frozen cadaveric elbows were randomly divided into a medial-lateral group and an olecranon osteotomy group, with 6 in each group. In the medial-lateral group, a medial approach was first used, and then a lateral approach. The sizes of the distal humeral articular surface exposed by each incision and the joined size were measured and calculated. In the olecranon osteotomy group, a posterior olecranon osteotomy approach was applied, and the maximal visible sizes of the articular surface were marked and calculated. Ratios of the maximal sizes of the distal humeral articular surface of the two approaches were compared. RESULTS: In the medial-lateral group, the medial approach could expose 2/5 of the medial trochlea and 1/3 of the capitellum, while the mean visible size of the distal humeral articular surface was 6.8 cm2 , 34.8% of the entire surface; the lateral approach can expose 3/7 of the capitellum and 1/4 of the medial trochlea, while the mean visible size of the distal humeral articular surface was 6.7 cm2 , 33.9% of the whole surface; for the combined medial-lateral approach, the mean scope exposed of the medial and lateral visible articular surface was 38.2% and 43.1%, respectively. Meanwhile, in the olecranon osteotomy group, the posterior olecranon osteotomy was found to expose most of the posterior distal humeral articular surface, except for 1/3 of the anterior trochlea and 1/4 of the anterior capitellum, and the visible range of articular surface was 65.3%. The combined medial-lateral approach exposed 9.2 cm2 in total, 46.9% of the whole distal humeral articular surface, which averaged 19.6 cm2 . However, the visible size of the distal humeral articular surface for the olecranon osteotomy approach was 13.7 cm2 , 63.1% of the entire distal humeral articular surface, which averaged 21.3 cm2 . There was a significant difference observed between the medial-lateral group (46.9%) and the olecranon osteotomy group (63.1%) for the maximal visible size of the distal humeral articular surface (t = 7.201, P = 0.001). CONCLUSIONS: The combined medial-lateral approach can expose 46.9% of the distal humeral articular surface, concentrating on the anterior part, so it can be recommended to treat intra-articular fractures with a simple pattern in the posterior with the anterior side of the distal humerus less comminuted.

Biomechanical analysis of a novel plating for intra-articular distal humerus fractures: combined anteromedial and anterolateral plating.

PURPOSE: The traditional strategy for fixing intra-articular distal humerus fractures is double plating placed in an orthogonal or parallel configuration, based on posterior approach. With a combined medial and lateral approach, a novel configuration of plating (combined anteromedial and anterolateral plating) has been used. In this study, we investigated the biomechanical properties of the novel plating by comparing it with orthogonal plating. METHODS: Based on the 3D morphology of a healthy subject's humerus, the models of simple intra-articular distal humerus fractures were simulated. Two configurations of plating were applied to fix the models: the novel plating (with one plate anteromedially and the other anterolaterally on distal humerus), and orthogonal plating. Stresses, displacement, and stiffness were simulated and calculated under the conditions of axial compression, rotation torsion, bending torsion, and valgus torsion by using finite element analysis. RESULTS: In all the conditions, the maximal von Mises stresses of the novel plating are similar to those of orthogonal plating, and the patterns of stress distribution are similar between these two configurations. However, the impact of high stresses was weaker on the novel plating. The maximal displacement of the novel plating is smaller than that of orthogonal plating. The stiffness of the novel plating is superior to that of orthogonal plating, with the improvements of 19.4%, 122.7%, 25.0%, and 54.2% in axial compression, rotation torsion, bending torsion, and valgus torsion, respectively. CONCLUSIONS: The novel plating is stronger than orthogonal plating without increasing stress magnitude when fixing simple intra-articular distal humerus fractures, which makes it a feasible alternative. Further biomechanical and clinical studies are needed for a decisive conclusion.

Open reduction through a posterior incision in the surgical treatment of shoulder posterior dislocation associated with proximal humeral fractures.

BACKGROUND: We explored the surgical technique of reducing the humeral head and repairing the fractures through a combined approach in the treatment of this complex injury. METHODS: Six patients with posterior shoulder dislocations associated with proximal humerus fractures were enrolled in this study. The posteriorly dislocated head was first reduced through a shoulder posterior incision and the ruptured posterior capsular tissues were repaired simultaneously using a suture anchor. The fractures were then reduced and fixed with a PHILOS through a deltopectoral approach. The affected shoulders were immobilized in a neutral position for 6 weeks postoperatively with a customized orthosis and then permitted active shoulder exercises after removal of the orthosis. At the last visit, union of the fractures was evaluated. Degrees of anterior forward of the affected shoulder were recorded. Outcomes were evaluated according to UCLA and Constant criteria. RESULTS: Six patients were followed up for an average of 24.5 ± 7.4 (range 13-35) months. At the last visit, the mean degree of anterior forward was 171.7 ± 7.5 (range 160-180) degrees. An average of 32.9 ± 1.2 (range 31-34) points was obtained according to UCLA criteria, demonstrating excellent and good results in two and four cases, respectively. The mean Constant score was 87.3 ± 4.1 (range 83-92) points. CONCLUSIONS: The dislocated humeral head can be reduced through a posterior approach, while fractures can be reduced and fixed through a deltopectoral approach. This technique has the advantages of simplicity and its minimally invasive approach for reducing the dislocation.

Magnesium enhances the chondrogenic differentiation of mesenchymal stem cells by inhibiting activated macrophage-induced inflammation.

Magnesium deficiency increases the generation of pro-inflammatory cytokines, which is consistently accompanied by the sensitization of cells such as neutrophils, macrophages and endothelial cells. We investigated the potential of magnesium to regulate macrophage polarization and macrophage-induced inflammation with or without lipopolysaccharide (LPS) and interferon-γ (IFN-γ) activation and further elucidated whether these effects impact the inhibitory functions of activated macrophage-induced inflammation on cartilage regeneration. The results showed that magnesium inhibited the activation of macrophages, as indicated by a significant reduction in the percentage of CCR7-positive cells, while the percentage of CD206-positive cells decreased to a lesser degree. After activation, both pro-inflammatory and anti-inflammatory cytokines were down-regulated at the mRNA level and certain cytokines (IL-1ß, IL-6 and IL-10) were decreased in the cell supernatant with the addition of magnesium. Moreover, magnesium decreased the nuclear translocation and phosphorylation of nuclear factor-κB (NF-κB) to impede its activation. A modified micromass culture system was applied to assess the effects of activated macrophage-conditioned medium with or without magnesium treatment on the chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). Magnesium enhanced the chondrogenic differentiation of hBMSCs by reversing the adverse effects of activated macrophage-induced inflammation.

Treatment of Transverse with or without Posterior Wall Fractures of Acetabulum Using a Modified Smith-Petersen Combined with Kocher-Langenbeck Approach.

BACKGROUND The aim of this study was to explore the surgical treatment of transverse with or without posterior wall fractures of the acetabulum. MATERIAL AND METHODS We surgically treated 21 consecutive cases of pure transverse (7 cases) and with posterior wall (14 cases) fractures of the acetabulum. The anterior column fractures were firstly reduced, temporarily fixed through a modified Smith-Petersen small incision, and finally fixed after the fixation of the posterior column and wall fractures, which were reduced and fixed through a Kocher-Langenbeck approach. The operative time, intra-operative blood loss, quality of reduction (Matta criteria), perioperative complications, osseous union, subsequent complications, and hip function evaluation were recorded. RESULTS The mean operative time was 198.1 min and the mean intra-operative blood loss was 938.1 ml. Anatomic reduction of the anterior column was obtained in 20 cases and was imperfect in 1 case. All posterior column and wall fractures were anatomically reduced. We followed up 18 cases for a mean duration of 16.3 (8-30) months. All the fractures achieved osseous union. The mean Harris score was 85.1 points, with an excellent result in 7 cases, good in 8, fair in 2, and poor in 1. According to modified Merle d' Aubigne and Postel score system, the results were excellent in 2 cases, good in 15, and poor in 1. Avascular necrosis of the femoral head occurred in 1 case, heterotopic ossification in 3 cases, and numbness of the anterolateral thigh in 6 cases. CONCLUSIONS For transverse with or without posterior wall fractures of the acetabulum, reduction and fixation of anterior and posterior column should be done in sequence, and a modified Smith-Petersen small incision might be a good choice in reduction and fixation of the anterior column because it possesses advantages of direct visualization and minimal invasion.

Comparison of the effect on bone healing process of different implants used in minimally invasive plate osteosynthesis: limited contact dynamic compression plate versus locking compression plate.

Minimally invasive plate osteosynthesis (MIPO) has been widely accepted because of its satisfactory clinical outcomes. However, the implant construct that works best for MIPO remains controversial. Different plate designs result in different influence mechanisms to blood flow. In this study, we created ulnar fractures in 42 beagle dogs and fixed the fractures using MIPO. The dogs were randomly divided into two groups and were fixed with a limited contact dynamic compression plate (LC-DCP) or a locking compression plate (LCP). Our study showed that with MIPO, there was no significant difference between the LCP and the LC-DCP in terms of fracture fixation, bone formation, or mineralization. Combined with the previous literature, we inferred that the healing process is affected by the quality of fracture reduction more than plate selection.

A Novel Approach for Treatment of Acetabular Fractures.

BACKGROUND There is no single approach that provides adequate exposure for treatment of all types of acetabular fractures. We describe our experience with an easier, relatively less invasive pubic symphysis approach (PSA) for the treatment of acetabular fractures. MATERIAL AND METHODS Between March 2011 and March 2012, fifteen patients with acetabular fracture underwent surgery using the PSA technique. Fracture reduction and treatment outcomes were assessed by clinical and radiological examination. Operation time, intraoperative blood loss and postoperative complications were documented. RESULTS Mean operative time was 222±78 minutes. Average blood loss was 993±361 mL. Anatomical reduction was achieved in all patients. Minimum follow-up period was 31 months. Postoperative hypoesthesia in the area of innervation of the lateral femoral cutaneous nerve was reported in one patient, with spontaneous recovery at one month after surgery. No complications were reported during the follow-up period. At the most recent follow up, clinical outcomes were graded as "excellent" in six patients, "good" in eight patients and "fair" in one patient based on the modified Merle d'Aubigné-Postel score. CONCLUSIONS PSA appears to be a timesaving and safe approach for treatment of acetabular fractures that affords good visual access and allows for excellent fracture reduction. Our preliminary results revealed a much lower incidence of complications than traditional approaches, suggesting PSA is an alternative for treatment of acetabular fractures.

A Novel Guidewire Aiming Device to Improve the Accuracy of Guidewire Insertion in Femoral Neck Fracture Surgery Using Cannulated Screw Fixation.

BACKGROUND The aim of this study was to improve the accuracy of guidewire insertion in the femoral neck fracture surgery using cannulated screw fixation. MATERIAL AND METHODS A novel aiming device was designed and manufactured. Between January 2010 and June 2012, 64 femoral neck fracture patients were included into the study. All 64 patients were divided into 2 groups randomly. The aiming device was used during the operation for patients in the experimental group, but not in the control group. RESULTS There were no statistically significant differences in operative time or bleed volume between the groups (P>0.05). The frequency of guidewire drilling was significantly lower in the experimental group than in the control group (P<0.05). The angle between the first cannulated screw and the central axis of the femoral neck in coronal plane and sagittal plane, and the distance between the bottom cannulated screw and the medial calcar femorale rim, were significantly smaller in the experimental group than in the control group (P<0.05). CONCLUSIONS The aiming device is simple in structure and easy to use. It could help surgeons to accurately insert cannulated screw guidewires. The aiming device is suitable for broad clinical use.

Effects of different surgical techniques on mid-distal humeral shaft vascularity: open reduction and internal fixation versus minimally invasive plate osteosynthesis.

BACKGROUND: Humeral shaft fractures are generally managed with the conventional posterior open reduction and internal fixation (ORIF) or minimally invasive plate osteosynthesis (MIPO). This study was aimed at comparing the outcomes of these surgical techniques in terms of the vascular integrity of the mid-distal humeral shaft. METHODS: Twelve upper limbs were harvested from 6 fresh cadavers. ORIF or MIPO was randomly performed on either side of each pair of limbs. The axillary artery was perfused with a latex-lead tetraoxide red solution to visualize the vascular structures. The vascular integrity of the humerus was examined by plain radiography and dissection. The periosteal filling achieved with each technique was scored and the scores compared. RESULTS: In each limb, one main nutrient artery entering the mid-distal humeral shaft anteromedially (83.3 %) or medially (16.7 %) was first identified. No case of injury to the main nutrient artery was noted for either surgical technique. Injuries to the accessory nutrient arteries entering the mid-distal humeral shaft from the posterior aspect were absent in the MIPO cases, but occurred in 52.9 % of the ORIF cases. In addition, MIPO was also superior to the open plate technique showed superior periosteal filling than. CONCLUSIONS: Our results showed that the MIPO technique is superior to the ORIF in terms of preserving the vascular integrity of the mid-distal humeral shaft.

Two-Tension-Band Technique in Revision Surgery for Fixation Failure of Patellar Fractures.

BACKGROUND Failed patellar fracture fixation is rare, and is usually attributed to technical errors. There are no specific details available on how to address this problem. We present our two-tension-band technique for fixing patellar fractures. MATERIAL AND METHODS Between March 2010 and March 2013, 4 men and 2 women with failed fixation patellar fractures were treated in our department. Their average age was 34 years (range 23-49 years). The initial fracture type was C1 in 3, C2 in 1, and C3 in 2, according to the AO classification. The initial fracture patterns included 3 transverse and 3 comminuted fractures. There were no open fractures. All patients underwent internal fixation with a modified anterior tension band (MATB) supplemented with cerclage wiring. All failures were caused by tension bands sliding past the tip of the Kirschner wires. The mean time between the primary and revision operations was 16.2 months (range 2-63 months). We revised the fractures by two-separate-tension-band technique. RESULTS The mean follow-up was 52 months (range 31-67 months). All patients healed radiographically without complications at an average of 14.7 weeks (range 8-20 weeks). The Bostman knee score was excellent in 3 and good in 3. All patients regained full extension and the mean range of flexion was 147.5° (135-155°). CONCLUSIONS Use of this two-tension-band technique can avoid technical errors and provide more secure fixation. We recommend it for both primary and revision surgery of patellar fractures.