Development and Validation of Two-Step Prediction Models for Postoperative Bedridden Status in Geriatric Intertrochanteric Hip Fractures.

Patients with intertrochanteric hip fractures are at an elevated risk of becoming bedridden compared with those with intraarticular hip fractures. Accurate risk assessments can help clinicians select postoperative rehabilitation strategies to mitigate the risk of bedridden status. This study aimed to develop a two-step prediction model to predict bedridden status at 3 months postoperatively: one model (first step) for prediction at the time of admission to help dictate postoperative rehabilitation plans; and another (second step) for prediction at the time before discharge to determine appropriate discharge destinations and home rehabilitation programs. Three-hundred and eighty-four patients were retrospectively reviewed and divided into a development group (n = 291) and external validation group (n = 93). We developed a two-step prediction model to predict the three-month bedridden status of patients with intertrochanteric fractures from the development group. The first (preoperative) model incorporated four simple predictors: age, dementia, American Society of Anesthesiologists physical status classification (ASA), and pre-fracture ambulatory status. The second (predischarge) model used an additional predictor, ambulation status before discharge. Model performances were evaluated using the external validation group. The preoperative model performances were area under ROC curve (AUC) = 0.72 (95%CI 0.61-0.83) and calibration slope = 1.22 (0.40-2.23). The predischarge model performances were AUC = 0.83 (0.74-0.92) and calibration slope = 0.89 (0.51-1.35). A decision curve analysis (DCA) showed a positive net benefit across a threshold probability between 10% and 35%, with a higher positive net benefit for the predischarge model. Our prediction models demonstrated good discrimination, calibration, and net benefit gains. Using readily available predictors for prognostic prediction can assist clinicians in planning individualized postoperative rehabilitation programs, home-based rehabilitation programs, and determining appropriate discharge destinations, especially in environments with limited resources.

Humerus shaft fractures, approaches and management.

Humeral shaft fracture is a common injury which can be treated either conservatively with functional bracing or with surgical fixation. Current evidence shows an increase in the rate of nonunion after conservative treatment, suggesting that indications for conservative treatment may need to be re-examined. This article updates trends in treatment for humeral shaft fracture. Indications for surgery, both for plate osteosynthesis with open reduction and internal fixation (ORIF) as well as for minimally invasive plate osteosynthesis (MIPO) and intramedullary nailing (IMN) are described. Recognition of the advantages and disadvantages of each technique can better define the role of the plate or nail and can aid in the selection of an appropriate surgical approach. ORIF with compression plate continues to have a role in the treatment of simple or AO/OTA type A fractures. The primary goal of minimal invasive osteosynthesis, a surgical technique involving small incisions, closed reduction or mini-open reduction that minimizes soft tissue dissection and helps preserve the periosteal blood supply, is to achieve bone union and the best possible functional outcomes. MIPO of the humerus is now well accepted as being less invasive and providing relative stability to allow indirect (secondary) bone healing with callus formation. MIPO approaches can be performed circumferentially to the humerus, including the proximal, middle and distal shaft. The classic MIPO approach is anterior MIPO, followed by posterior, anterolateral and anteromedial MIPO. IMN is also an option for treating humerus fractures. In the past, IMN was not widely used due to the potential for complications such as shoulder impingement and elbow problems as well as the limited availability of implants and the steep learning curve of this surgical technique. Over the past decade, the launch of a new design of straight antegrade and retrograde IMN with established techniques has encouraged more surgeons to use IMN as an alternative option. Methods of dealing with concomitant and post-treatment radial nerve palsy have also been evolving, including the use of ultrasound for diagnosis of radial nerve conditions. Radial nerves with contusion, entrapment or laceration can be detected using ultrasound with reliability comparable to intraoperative findings. Trends in treatment of radial nerve palsy are described below. Future larger randomized controlled trials comparing conservative and operative management are necessary to further develop appropriate guidelines.

Silent iatrogenic pseudoaneurysm after intertrochanteric fracture fixation with proximal femoral nailing and cerclage wiring: case report and review of literature.

Pseudoaneurysm is a rare complication after intertrochanteric fracture fixation. Herein, we present a rare case of late development of a pseudoaneurysm with silent clinical symptoms. The case was a 91-year-old woman treated with proximal femoral nailing and cerclage wiring. Postoperatively, the patient was able to ambulate with a walker without abnormal symptoms. During the follow-ups, the radiographic images showed progressive cortical scalloping on the medial femoral shaft. Ultrasonography revealed a yin-yang sign, and a CT scan confirmed a pseudoaneurysm at the profunda femoris artery (PFA). In this case, many possible causes of pseudoaneurysm were hypothesized. We showed that the excessive displaced, long spiral pattern of an intertrochanteric fracture, which was irreducible by a closed technique, is the risk of a PFA injury. An atherosclerotic vessel was seen in preoperative radiography, indicating poor vessel elasticity which may be a risk of vessel tear during fracture reduction using multiple reduction instruments in excessive displaced fracture. Moreover, over-penetration when drilling should not be overlooked. We also discuss the predisposing factors, surgical techniques which may lead to this type of PFA injury and summarize the literature of pseudoaneurysms related to intertrochanteric fracture fixation.

Danger zone for screw placement in minimally invasive plate osteosynthesis (MIPO) of diaphyseal fractures of forearm: a cadaveric study.

PURPOSES: To identify the anatomical relationship between neurovascular structures and screws and to evaluate the danger zone of screw placement during minimally invasive plate osteosynthesis (MIPO) technique following the volar approach for the radius and the subcutaneous approach for the ulna in diaphyseal forearm fractures. METHODS: Sixteen cadaveric forearms were fixed with a 3.5-mm, 14-hole, locking compression plate (LCP) using the MIPO technique with a volar approach of the radius. Two locking screws were fixed at each end via two separated incisions, and the remaining ten  screws were inserted percutaneously. The same MIPO technique was performed at the ulna with the subcutaneous approach. The forearms were then dissected to identify any damage to or direct contact between the screws and the radial artery (RA), the superficial branch of the radial nerve (SBRN), the posterior interosseous nerve (PIN), and the dorsal cutaneous branch of the ulnar nerve (DCBUN). The distances from the screws to the structures at risk, as well as the radial and ulnar length, were measured. RESULTS: The average lengths of the radius and ulna were 24.74 cm and 25.93 cm, respectively. On the volar aspect of the radius, the danger zones of RA and SRN were between 15.26 and 81.24% of the length of the radius from the radial styloid. The zone of PIN injury at the posterior aspect of the radius was between 41.45 and 81.24% of the length of the radius from the radial styloid. Meanwhile, the danger zone of DCBUN was between 12.21 and 27.23% of the ulnar length from the ulnar styloid. CONCLUSION: Based on our study, the percutaneous screw fixation in MIPO for the treatment of diaphyseal fractures of the forearm is a dangerous procedure, especially for the volar approach of the entire radius and the subcutaneous approach of the distal ulna.

Nanovibrational Stimulation of Mesenchymal Stem Cells Induces Therapeutic Reactive Oxygen Species and Inflammation for Three-Dimensional Bone Tissue Engineering.

There is a pressing clinical need to develop cell-based bone therapies due to a lack of viable, autologous bone grafts and a growing demand for bone grafts in musculoskeletal surgery. Such therapies can be tissue engineered and cellular, such as osteoblasts, combined with a material scaffold. Because mesenchymal stem cells (MSCs) are both available and fast growing compared to mature osteoblasts, therapies that utilize these progenitor cells are particularly promising. We have developed a nanovibrational bioreactor that can convert MSCs into bone-forming osteoblasts in two- and three-dimensional, but the mechanisms involved in this osteoinduction process remain unclear. Here, to elucidate this mechanism, we use increasing vibrational amplitude, from 30 nm (N30) to 90 nm (N90) amplitudes at 1000 Hz and assess MSC metabolite, gene, and protein changes. These approaches reveal that dose-dependent changes occur in MSCs' responses to increased vibrational amplitude, particularly in adhesion and mechanosensitive ion channel expression and that energetic metabolic pathways are activated, leading to low-level reactive oxygen species (ROS) production and to low-level inflammation as well as to ROS- and inflammation-balancing pathways. These events are analogous to those that occur in the natural bone-healing processes. We have also developed a tissue engineered MSC-laden scaffold designed using cells' mechanical memory, driven by the stronger N90 stimulation. These mechanistic insights and cell-scaffold design are underpinned by a process that is free of inductive chemicals.

How to determine the surgical approach in Hoffa fractures?

Surgical approach selection and fixation of Hoffa fractures is difficult and remains controversial. Evolving trends emphasize the importance of fracture morphology, fracture location, and comminution, all of which guide decisions regarding surgical approach and implant selection. This focused review highlights factors affecting Hoffa fracture available surgical approaches, treatment outcomes, and recommendations for selecting an optimal approach.

Antibacterial surface modification of titanium implants in orthopaedics.

The use of biomaterials in orthopaedics for joint replacement, fracture healing and bone regeneration is a rapidly expanding field. Infection of these biomaterials is a major healthcare burden, leading to significant morbidity and mortality. Furthermore, the cost to healthcare systems is increasing dramatically. With advances in implant design and production, research has predominately focussed on osseointegration; however, modification of implant material, surface topography and chemistry can also provide antibacterial activity. With the increasing burden of infection, it is vitally important that we consider the bacterial interaction with the biomaterial and the host when designing and manufacturing future implants. During this review, we will elucidate the interaction between patient, biomaterial surface and bacteria. We aim to review current and developing surface modifications with a view towards antibacterial orthopaedic implants for clinical applications.

Relationships between Hoffa fragment size and surgical approach selection: a cadaveric study.

INTRODUCTION: Fixation of a small Hoffa fragment requires a selection of the proper surgical approach for reduction and posterior to anterior screws fixation. However, currently there are no guidelines regarding how to select the best approach for small posterior Hoffa fractures. OBJECTIVES: To compare the size of Hoffa fractures that are appropriate for reduction and fixation with the medial parapatellar approach (MPPA) and those which require the direct medial approach (DMA), and to make a similar comparison between the lateral parapatellar approach (LPPA) and the posterolateral approach (PLA). MATERIALS AND METHODS: Twenty extremities of fresh cadavers were included. After completion of each approach, the articular surface boundaries were marked and soft tissue was removed. On the medial condyle, an imaginary line was drawn from the most anterior (A) to the most posterior (B) point, representing the AP diameter (d3). The most posterior boundary of MPPA (C) and the most anterior boundary of DMA (D) were similarly marked. Distances between B and C (d1) and between B and D (d2) were measured as well as the anterior-posterior diameter of the condyle (d3). The same measurements were made for the lateral condyle. RESULTS: On the medial condyle, the average values of d1, d2, and d3 were 10.8 mm ± 3.8, 17.3 mm ± 3.3, and 60.1 mm ± 3.2, while percentages of d1/d3 and d2/d3 were 18.3% ± 6.4 and 28.7% ± 4.7. In lateral condyle, the averages for d1, d2, d3 were 6.1 mm ± 1.4, 12.1 mm ± 2.8 and 60.9 mm ± 3.3 mm and the percentages of d1/d3 and d2/d3 were 10.1% ± 2.3 and 19.9% ± 4.9. CONCLUSIONS: When the Hoffa fragment is less than 18.3% of the AP diameter of medial condyle or 10.1% of lateral condyle, the fracture is invisible with the PPA. When the Hoffa fragment is more than 28.7% of the medial condyle or 19.9% of the lateral condyle, the PPA should be selected. If the Hoffa fragment is less than 28.7% of the medial condyle or 19.9% of the lateral condyle, the DMA or PLA with posterior-to-anterior screws is recommended. Combined approaches should be considered in some complex cases with articular comminution.

Posterolateral tibial plateau fractures, how to buttress? Reversed L posteromedial or the posterolateral approach: a comparative cadaveric study.

INTRODUCTION: The selection of a surgical approach for buttressing posterolateral tibial plateau fractures is controversial. OBJECTIVE: This study compared the surgical exposure area between the reversed L posteromedial approach (R-PM) and the posterolateral (PL) approach using the lateral plateau width as a metric. MATERIALS AND METHODS: Twenty lower extremities from fresh frozen cadavers were included. The R-PM approach was used first and the boundary of the posterior tibial cortex exposure was marked with metal pins. With the same specimens, the PL approach was then performed and the exposure area was marked. After removing all soft tissue, an imaginary line was drawn from the lateral plateau rim anterior to the fibular head (L) to the posteromedial ridge of the tibia (M). Additional metal pins were used to indicate bony reference landmarks at the joint line on the posterior tibial plateau, including the lateral tibial spine (S), the lateral boundary with the PM approach (LPM) and the lateral boundary with the PL approach (LPL). All distances were measured using S as the reference point. RESULTS: The average distance from S to L, referred to as the lateral plateau width (A), was 32.62 mm. The average distances from S to LPM (B) and from S to LPL measured as a percentage of A were 43.72 and 81.41%, respectively. The average R-PM approach blind distance from LPM to LPL (C) as a percentage of the lateral plateau width was 58.45%, while the distance LPL to L (D), which represents the invisible blind distance with both approaches, was 15.37% of that width. CONCLUSIONS: The PL approach provides better access for buttressing the posterolateral tibial plateau fracture than the R-PM approach. With the R-PM approach, the blind area on the lateral plateau which can be accessed only by the PL approach starts approximately at 43.72% and ends at 81.41% of the lateral tibial plateau width. When a fracture is located in this zone, the posterolateral approach is recommended.

Stimulation of 3D osteogenesis by mesenchymal stem cells using a nanovibrational bioreactor.

Bone grafts are one of the most commonly transplanted tissues. However, autologous grafts are in short supply, and can be associated with pain and donor-site morbidity. The creation of tissue-engineered bone grafts could help to fulfil clinical demand and provide a crucial resource for drug screening. Here, we show that vibrations of nanoscale amplitude provided by a newly developed bioreactor can differentiate a potential autologous cell source, mesenchymal stem cells (MSCs), into mineralized tissue in 3D. We demonstrate that nanoscale mechanotransduction can stimulate osteogenesis independently of other environmental factors, such as matrix rigidity. We show this by generating mineralized matrix from MSCs seeded in collagen gels with stiffness an order of magnitude below the stiffness of gels needed to induce bone formation in vitro. Our approach is scalable and can be compatible with 3D scaffolds.

Publisher Correction: Stimulation of 3D osteogenesis by mesenchymal stem cells using a nanovibrational bioreactor.

In the version of this Article originally published, in Fig. 4f, the asterisk was missing; in Fig. 6a-c, the labels 'Wnt/ß-catenin signalling', 'Wnt/Ca+ pathway' and 'ERK' and their associated lines/arrows were missing; and in Fig. 6d and in the sentence beginning "In MSCs that were...", 'myosin' and 'nanostimulated', respectively, were spelt incorrectly. These errors have now been corrected in all versions of the Article.