Artificial intelligence-based analyses of varus leg alignment and after high tibial osteotomy show high accuracy and reproducibility.

PURPOSE: The aim of this study was to investigate the performance of an artificial intelligence (AI)-based software for fully automated analysis of leg alignment pre- and postoperatively after high tibial osteotomy (HTO) on long-leg radiographs (LLRs). METHODS: Long-leg radiographs of 95 patients with varus malalignment that underwent medial open-wedge HTO were analyzed pre- and postoperatively. Three investigators and an AI software using deep learning algorithms (LAMA™, ImageBiopsy Lab, Vienna, Austria) evaluated the hip-knee-ankle angle (HKA), mechanical axis deviation (MAD), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA), and mechanical lateral distal femoral angle (mLDFA). All measurements were performed twice and the performance of the AI software was compared with individual human readers using a Bayesian mixed model. In addition, the inter-observer intraclass correlation coefficient (ICC) for inter-observer reliability was evaluated by comparing measurements from manual readers. The intra-reader variability for manual measurements and the AI-based software was evaluated using the intra-observer ICC. RESULTS: Initial varus malalignment was corrected to slight valgus alignment after HTO. Measured by the AI algorithm and manually HKA (5.36° ± 3.03° and 5.47° ± 2.90° to - 0.70 ± 2.34 and - 0.54 ± 2.31), MAD (19.38 mm ± 11.39 mm and 20.17 mm ± 10.99 mm to - 2.68 ± 8.75 and - 2.10 ± 8.61) and MPTA (86.29° ± 2.42° and 86.08° ± 2.34° to 91.6 ± 3.0 and 91.81 ± 2.54) changed significantly from pre- to postoperative, while JLCA and mLDFA were not altered. The fully automated AI-based analyses showed no significant differences for all measurements compared with manual reads neither in native preoperative radiographs nor postoperatively after HTO. Mean absolute differences between the AI-based software and mean manual observer measurements were 0.5° or less for all measurements. Inter-observer ICCs for manual measurements were good to excellent for all measurements, except for JLCA, which showed moderate inter-observer ICCs. Intra-observer ICCs for manual measurements were excellent for all measurements, except for JLCA and for MPTA postoperatively. For the AI-aided analyses, repeated measurements showed entirely consistent results for all measurements with an intra-observer ICC of 1.0. CONCLUSIONS: The AI-based software can provide fully automated analyses of native long-leg radiographs in patients with varus malalignment and after HTO with great accuracy and reproducibility and could support clinical workflows. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Deep Learning for Fully Automated Radiographic Measurements of the Pelvis and Hip.

The morphometry of the hip and pelvis can be evaluated in native radiographs. Artificial-intelligence-assisted analyses provide objective, accurate, and reproducible results. This study investigates the performance of an artificial intelligence (AI)-based software using deep learning algorithms to measure radiological parameters that identify femoroacetabular impingement and hip dysplasia. Sixty-two radiographs (124 hips) were manually evaluated by three observers and fully automated analyses were performed by an AI-driven software (HIPPO™, ImageBiopsy Lab, Vienna, Austria). We compared the performance of the three human readers with the HIPPO™ using a Bayesian mixed model. For this purpose, we used the absolute deviation from the median ratings of all readers and HIPPO™. Our results indicate a high probability that the AI-driven software ranks better than at least one manual reader for the majority of outcome measures. Hence, fully automated analyses could provide reproducible results and facilitate identifying radiographic signs of hip disorders.

The Impact of Obesity on the Health of the Older Population: A Cross-Sectional Study on the Relationship between Health-Related Quality of Life and Body Mass Index across Different Age Groups.

Obesity is strongly associated with mortality and morbidity, but there is a lack of data on its impact on health-related quality of life (HRQoL) across different age groups. Therefore, this study's objective was to determine the association between body mass index (BMI) and HRQoL in the Austrian adult population based on age groups using the 36-Item Short Form (SF-36) survey. METHODS: The SF-36 survey was sent to 500 randomly assigned Austrian adults (response rate: 80.6%). This study assessed HRQoL subscale and component scores based on gender, level of education, smoking status, and alcohol consumption in 403 participants. RESULTS: Increasing BMI is associated with a negative impact on all domains of physical health and social function. The study uncovered substantial variations in the impact of increasing BMI on HRQoL across different age groups, with a pronounced effect observed in the physical components, particularly among individuals aged 65-74. CONCLUSIONS: BMI is negatively associated with the physical aspects of HRQoL and social function, affecting various adult age groups differently. Consequently, our results emphasize assessing different age groups and possible influencing factors on HRQoL, such as BMI, for further optimization in designing prevention programs against obesity.

Artificial Intelligence in Orthopedic Radiography Analysis: A Narrative Review.

Artificial intelligence (AI) in medicine is a rapidly growing field. In orthopedics, the clinical implementations of AI have not yet reached their full potential. Deep learning algorithms have shown promising results in computed radiographs for fracture detection, classification of OA, bone age, as well as automated measurements of the lower extremities. Studies investigating the performance of AI compared to trained human readers often show equal or better results, although human validation is indispensable at the current standards. The objective of this narrative review is to give an overview of AI in medicine and summarize the current applications of AI in orthopedic radiography imaging. Due to the different AI software and study design, it is difficult to find a clear structure in this field. To produce more homogeneous studies, open-source access to AI software codes and a consensus on study design should be aimed for.

Influence of the femoral entry point for intramedullary alignment in total knee arthroplasty: A computer-aided design approach.

OBJECTIVES: The aim of this study was to simulate different entry points and investigate potential angulation errors of the intramedullary device and resulting changes in the distal femoral cut using a computer-aided design (CAD) approach. MATERIALS AND METHODS: We used a CAD approach to simulate various distal femoral entry points for intramedullary instrumentation. Simulations were performed on (i) a commercially available three-dimensional (3D) CAD model of a human femur (DigitalFemur) and (ii) a digital 3D model of an analogue large femur model produced using a coordinate measuring machine (FaroFemur). Divergent insertion points medial, lateral, anterior and posterior to the ideal position were simulated. Angulation deviations of the resulting positions of the intramedullary rod were measured and changes in the anatomical-mechanical axis angle were calculated. Differences between the two simulation models were quantified. RESULTS: The ideal entry point in the FaroFemur was 9.9 mm anterior and 4.3 mm medial to the apex of the intercondylar notch, and 9.2 mm anterior and 3.6 mm medial in the DigitalFemur. A medial entry point increased the angle between the anatomical femoral axis and the alignment rod in the FaroFemur and DigitalFemur (with 5 mm displacement 2.510° and 2.363°, respectively; with 10 mm displacement 3.239° and 3.283°, respectively). In contrast, a lateral entry point decreased the angle between the anatomical femoral axis and the alignment rod (with 5 mm displacement 2.267° and 2.262°, respectively; with 10 mm displacement 3.158° and 3.731°, respectively). An anterior entry point changed the angle between the anatomical femoral axis and the alignment rod towards extension (1.802° in the FaroFemur; 2.142° in the DigitalFemur), while a posterior entry point generated a deviation toward flexion (2.045° in the FaroFemur; 2.055° in the DigitalFemur). The mean difference between the two models was 0.108±0.121° with the highest difference for anterior displacement. CONCLUSION: Minor deviations of the entry point for intramedullary instrumentation during total knee arthroplasty can result in malalignment of several degrees.

Pilot Study and Preliminary Results of Biodegradable Intramedullary Nailing of Forearm Fractures in Children.

(1) Background: Diaphyseal forearm fractures are a common injury in children and adolescents. When operative treatment is needed, elastic stable intramedullary nailing (ESIN) is the most common surgical procedure. Although there is no clear evidence, hardware removal after fracture healing is performed in many patients. Often, the primary minimal invasive incision needs to be widened during implant removal. In order to decrease the burden of care of pediatric fractures, significant efforts were made to develop biodegradable implants, which make hardware removal unnecessary. Our study will conduct an observational trial on the clinical use of the Activa IM-Nail™ in forearm fractures in children between 3 and 13 years of age. The objective of this trial is to evaluate the risks and benefits of the Activa IM-Nail™. Among other objectives, the rate of refracture will be determined. (2) Methods: An international Europe-based, multicenter, prospective, single-arm, open-label study will be performed to ascertain the rate of refracture and to determine the subjective benefits of Activa IM-Nail™ for patients, parents and other caregivers. The study will include clinical follow-up including early post-operative complication, radiographs until bony healing and an additional follow-up after 1 year. At this stage, preliminary results and early complications on 76 patients are analyzed in this study and presented. (3) Results: As of April 2022, 76 patients were enrolled as per study protocol. There were 31 girls (40.8%) and 45 boys (59.2%). The mean age at the time of inclusion was 8.9 years (±2.4 years). The mean operation time was 58.9 ± 22.9 min (range, 15-119 min). The mean follow-up time was 8.9 ± 5.1 months (range, 0.2-18.6). Up to now, one refracture has occurred in one child falling from a height of about one meter 7 months after index surgery (1/76; 1.3%). (4) Conclusion: The research project assesses the safety and effectiveness of Activa IM-Nails™ as part of the surgical treatment of dislocated forearm fractures in children in the context of a PMCF study. The use of Activa IM-Nails™ with regard to various objectives, including postoperative complications and refracture rate, seems to be equal to the standard titan ESIN procedure compared to the literature. Preliminary results are encouraging and are made available.

[Autologous chondrocyte transplantation with bone augmentation for the treatment of osteochodral defects of the knee : Treatment of osteochondral defects of the femoral condyles using autologous cancellous bone from the iliac crest combined with matrix-guided autologous chondrocyte transplantation]. / Autologe Knorpelzelltransplantation mit Knochenaufbau zur Behandlung osteochondraler Defekte am Knie : Behandlung osteochondraler Defekte der Femurkondylen mittels autologer Spongiosazylinder aus dem Beckenkamm kombiniert mit matrixgestützter autologer Chondrozytentransplantation.

OBJECTIVE: Open treatment of osteochondral defects of the knee to fully restore the bony defect and the articular surface. INDICATIONS: Focal, symptomatic osteochondral lesions of the knee with a depth of ≥ 5 mm and a surface of ≥ 1.5 cm2. CONTRAINDICATIONS: Osteoarthritis, kissing lesions, age > 50 years, untreated ligament instability or relevant malalignment, insufficient containment, inflammatory joint disease. SURGICAL TECHNIQUE: Two-step procedure: Step 1 (arthroscopy): evaluation of the defect, harvesting of cartilage tissue for chondrocyte cultivation, if needed treatment of concomitant pathologies. Step 2 (open surgery): arthrotomy, preparation of the defect, transfer of iliac crest cancellous bone plugs to the defect, preparation of the cartilage defect (can exceed the size of the bony defect), matrix-guided autologous chondrocyte transplantation. POSTOPERATIVE MANAGEMENT: Step 1: therapy follows the needs of concomitant procedures, with early full weight bearing as tolerated. Step 2: no suction drain, knee brace in extension for week 1, followed by stepwise increase of flexion, partial weight bearing for 6 weeks, continuous passive motion starting on postoperative day 1. RESULTS: Since 2018, 8 patients (mean age 29.4 years) have been treated with the described technique. All patients were available for follow-up examination after an average of 12 months. The KOOS (Knee injury and Osteoarthritis Outcome Score) improved from 45.8 to 81.3 and the postoperative X­rays showed bony healing of the cancellous bone plugs in all patients. The MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score reached 80.4 points.

Surgical treatment of anterior sternoclavicular dislocation associated with midshaft clavicle fracture: A case report.

A combination of an anterior sternoclavicular (SC) joint dislocation with a midshaft clavicle fracture is an extremely rare injury. If left untreated, it can lead to severely impaired function of the shoulder with a high risk for complications. A 45-year-old male patient presented with pain and impaired range of motion (ROM) in the left shoulder after a mountain bike crash. Radiographs and a computed tomography scan showed an anterior dislocation of the left SC joint and an ipsilateral midshaft fracture of the clavicle. Open reduction and internal fixation (ORIF) of the clavicle combined with SC joint stabilization using transosseous sutures was performed. Postoperatively, a shoulder-arm bandage was applied with passive motion starting on the first postoperative day. During follow-up, the patient showed an improved clinical function and could return to work after three weeks. Radiographs at eight weeks showed fracture healing without any signs of recurrent SC dislocation. At the final follow-up at 12 weeks, the patient returned to his pre-injury activity level and recreational sports. Despite minimal redislocation in the SC joint, the Constant-Murley Score showed a continuous improvement with 93%, compared to the contralateral side. In conclusion, surgical treatment of anterior SC joint dislocation with a midshaft clavicle fracture can restore shoulder function with no surgery-associated complications.

Biotribological Tests of Osteochondral Grafts after Treatment with Pro-Inflammatory Cytokines.

OBJECTIVE: During osteoarthritis progression, cartilage degrades in a manner that influences its biomechanical and biotribological properties, while chondrocytes reduce the synthesis of extracellular matrix components and become apoptotic. This study investigates the effects of inflammation on cartilage under biomechanical stress using biotribological tests. METHODS: Bovine osteochondral grafts from five animals were punched out from the medial condyle and treated with or without pro-inflammatory cytokines (interleukin-1ß [IL-1ß], tumor necrosis factor-α [TNF-α], IL-6) for 2 weeks. After incubation, biotribological tests were performed for 2 hours (alternating 10 minutes test and pause respectively at 39°C, 180 N, 1 Hz, and 2 mm stroke). Before and after testing, the cartilage surface was imaged with a 3-dimensional microscope. During testing, the coefficient of friction (COF) was measured, while gene expression analysis and investigation of metabolic activity of chondrocytes were carried out after testing. Histological sections of the tissue and wear debris from the test fluid were also analyzed. RESULTS: After biotribological tests, surface cracks were found in both treated and untreated osteochondral grafts. In treated grafts, the COF increased, and the proteoglycan content in the cartilage tissue decreased, leading to structural changes. Chondrocytes from treated grafts showed increased expression of genes encoding for degradative enzymes, while cartilage-specific gene expression and metabolic activity exhibited no significant differences between treated and untreated groups. No measurable difference in the wear debris in the test fluid was found. CONCLUSIONS: Treatment of osteochondral grafts with cytokines results in a significantly increased COF, while also leading to significant changes in cartilage proteoglycan content and cartilage matrix compression during biotribological tests.

Concentration-Dependent Effects of Cobalt and Chromium Ions on Osteoarthritic Chondrocytes.

OBJECTIVE: Cobalt and chromium (CoCr) ions from metal implants are released into the joint due to biotribocorrosion, inducing apoptosis and altering gene expression in various cell types. Here, we asked whether CoCr ions concentration-dependently changed viability, transcriptional activity, and inflammatory response in human articular chondrocytes. DESIGN: Human articular chondrocytes were exposed to Co (1.02-16.33 ppm) and Cr (0.42-6.66 ppm) ions and cell viability and early/late apoptosis (annexin V and 7-AAD) were assessed in 2-dimensional cell cultures using the XTT assay and flow cytometry, respectively. Changes in chondrocyte morphology were assessed using transmitted light microscopy. The effects of CoCr ions on transcriptional activity of chondrocytes were evaluated by quantitative polymerase chain reaction (qPCR). The inflammatory responses were determined by measuring the levels of released pro-inflammatory cytokines (interleukin-1ß [IL-1ß], IL-6, IL-8, and tumor necrosis factor-α [TNF-α]). RESULTS: CoCr ions concentration-dependently reduced metabolic activity and induced early and late apoptosis after 24 hours in culture. After 72 hours, the majority of chondrocytes (>90%) were apoptotic at the highest concentrations of CoCr ions (16.33/6/66 ppm). SOX9 expression was concentration-dependently enhanced, whereas expression of COL2A1 linearly decreased after 24 hours. IL-8 release was enhanced proportionally to CoCr ions levels, whereas IL-1ß, IL-6, and TNF-α levels were not affected by the treatments. CONCLUSIONS: CoCr ions showed concentration- and time-dependent effects on articular chondrocytes. Fractions of apoptotic articular chondrocytes were proportional to CoCr ion concentrations. In addition, metabolic activity and expression of chondrocyte-specific genes were decreased by CoCr ions. Furthermore, exposure to CoCr ions caused a release of pro-inflammatory cytokines.

Anterocentral Portal in Ankle Arthroscopy.

BACKGROUND: The anterocentral portal is not a standard portal in anterior ankle arthroscopy due to its proximity to the anterior neurovascular bundle. However, it provides certain advantages, including a wide field of vision, and portal changes become redundant. The purpose of this study was to evaluate the neurovascular complications after anterior ankle arthroscopy using the anterocentral portal. METHODS: We retrospectively identified patients who had undergone anterior ankle arthroscopy with an anterocentral portal at our institution from 2013 to 2018. Medical record data were reviewed and patients were invited for clinical follow-up, where a clinical examination, quantitative sensory testing for the deep peroneal nerve, and ultrasonography of the structures at risk were performed. A total of 101 patients (105 arthroscopies) were identified and evaluated at a mean follow-up of 31.5 ± 17.7 months. RESULTS: Leading indications to surgery were heterogeneous and included anterior impingement (48.6%), osteochondral lesions of the talus (24.8%), chronic ankle instability (14.3%), and fractures (8.6%). The overall complication rate was 7.6%, and no major complications were observed. In 1.9% (2/105) of the cases, the complications were associated with the anterocentral portal and included injury to the medial branch of the superficial nerve (1/105) and to the deep peroneal nerve (1/105). Injury to the deep peroneal nerve was associated with a loss of detection and nociception. There were no injuries to the anterior tibial artery. In 41.9% (44/105) of the cases, only 1 working portal was used in addition to the anterocentral portal, and in 19% (20/105) the anterolateral portal could be avoided. Ultrasonography confirmed the integrity of the deep peroneal nerve, the medial branch of the superficial peroneal nerve, and the anterior tibial artery in all patients. Patients with nerve injuries associated with the anterocentral portal showed no signs of neuroma or pseudoaneurysm. CONCLUSION: Using a standardized technique, the anterocentral portal in ankle arthroscopy is safe with a low number of neurovascular injuries and can be recommended as a standard portal. The anterolateral portal remains associated with a high number of injuries to the superficial peroneal nerve. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Biotribological Testing and Analysis of Articular Cartilage Sliding against Metal for Implants.

Osteochondral defects in middle-aged patients might be treated with focal metallic implants. First developed for defects in the knee joint, implants are now available for the shoulder, hip, ankle and the first metatarsalphalangeal joint. While providing pain reduction and clinical improvement, progressive degenerative changes of the opposing cartilage are observed in many patients. The mechanisms leading to this damage are not fully understood. This protocol describes a tribological experiment to simulate a metal-on-cartilage pairing and comprehensive analysis of the articular cartilage. Metal implant material is tested against bovine osteochondral cylinders as a model for human articular cartilage. By applying different loads and sliding speeds, physiological loading conditions can be imitated. To provide a comprehensive analysis of the effects on the articular cartilage, histology, metabolic activity and gene expression analysis are described in this protocol. The main advantage of tribological testing is that loading parameters can be adjusted freely to simulate in vivo conditions. Furthermore, different testing solutions might be used to investigate the influence of lubrication or pro-inflammatory agents. By using gene expression analysis for cartilage-specific genes and catabolic genes, early changes in the metabolism of articular chondrocytes in response to mechanical loading might be detected.

Effects of Loading Conditions on Articular Cartilage in a Metal-on-Cartilage Pairing.

The aim of this in vitro study was to investigate the response of articular cartilage to frictional load when sliding against a metal implant, and identify potential mechanisms of damage to articular cartilage in a metal-on-cartilage pairing. Bovine osteochondral cylinders were reciprocally slid against metal cylinders (cobalt-chromium-molybdenum alloy) with several variations of load and sliding velocity using a microtribometer. The effects of different loads and velocities, and the resulting friction coefficients on articular cartilage, were evaluated by measuring histological and metabolic outcomes. Moreover, the biotribocorrosion of the metal was determined. Chondrocytes stimulated with high load and velocity showed increased metabolic activity and cartilage-specific gene expression. In addition, higher load and velocity resulted in biotribocorrosion of the metal implant and damage to the surface of the articular cartilage, whereas low velocity and a high coefficient of friction increased the expression of catabolic genes. Articular cartilage showed particular responses to load and velocity when sliding against a metal implant. Moreover, metal implants showed tribocorrosion. Therefore, corrosion particles may play a role in the mechano-biochemical wear of articular cartilage after implantation of a metal implant. These findings may be useful to surgeons performing resurfacing procedures and total knee arthroplasty. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 37:2531-2539, 2019.

Effect of osteochondral graft orientation in a biotribological test system.

Autologous osteochondral transplantation (AOT) utilizing autografts is a widely used technique for the treatment of small-to-medium cartilage defects occurring in knee and ankle joints. The application of viable cartilage and bone ensures proper integration, early weight bearing, as well as restoration of biomechanical and biotribological properties. However, alignment of the autografts onto the defect site remains a pivotal aspect of reinstating the properties of the joint toward successful autograft integration. This is the first study to perform tests with different orientations of osteochondral grafts in a cartilage-on-cartilage test system. The objective was to estimate if there are differences between aligned and 90°-rotated grafts concerning molecular biological and biomechanical parameters. Tissue viability, assessed by XTT assay indicated lower metabolic activity in tested osteochondral grafts (aligned, p = 0.0148 and 90°-rotated, p = 0.0760) in favor of a higher anabolic gene expression (aligned, p = 0.0030 and 90°-rotated, 0.0027). Tissue structure was evaluated by Safranin O histology and microscopic images of the surface. Aligned and 90°-rotated grafts revealed no apparent differences between proteoglycan content or cracks and fissures on the cartilage surface. Test medium analyzed after tribological tests for their sulfated glycosaminoglycan content revealed no differences (p = 0.3282). During the tests, both the friction coefficient and the relative displacement between the two cartilage surfaces were measured, with no significant difference in both parameters (COF, p = 0.2232 and relative displacement, p = 0.3185). From the methods we deployed, this study can infer that there are no differences between aligned and 90°-rotated osteochondral grafts after tribological tests in the used ex vivo tissue model. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res.

Impact of timing of surgery in elderly hip fracture patients: a systematic review and meta-analysis.

We aimed to assess the impact of timing of surgery in elderly patients with acute hip fracture on morbidity and mortality. We systematically searched MEDLINE, the Cochrane Library, Embase, PubMed, and trial registries from 01/1997 to 05/2017, as well as reference lists of relevant reviews, archives of orthopaedic conferences, and contacted experts. Eligible studies had to be randomised controlled trials (RCTs) or prospective cohort studies, including patients 60 years or older with acute hip fracture. Two authors independently assessed study eligibility, abstracted data, and critically appraised study quality. We conducted meta-analyses using the generic inverse variance model. We included 28 prospective observational studies reporting data of 31,242 patients. Patients operated on within 48 hours had a 20% lower risk of dying within 12 months (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.66-0.97). No statistical significant different mortality risk was observed when comparing patients operated on within or after 24 hours (RR 0.82, 95% CI 0.67-1.01). Adjusted data demonstrated fewer complications (8% vs. 17%) in patients who had early surgery, and increasing risk for pressure ulcers with increased time of delay in another study. Early hip surgery within 48 hours was associated with lower mortality risk and fewer perioperative complications.

Resorbable implants in pediatric fracture treatment.

Pediatric osteosynthesis has developed over the last 20 years, thereby reducing medical and economic burden, including long and expensive hospitalization. Currently, conventional and rigid alloying systems such as titanium are used for stabilization of bone fractures in children. In many cases, implants must be removed, as otherwise growth would be impeded. Biodegradable implant materials exhibit beneficial properties and would make a second removal surgery unnecessary. In the following article, we will give an overview of implant materials that are currently used in pediatric traumatology with a focus on Mg-based implants. Furthermore, we will discuss current scientific knowledge on resorbable implants, including results from pre-clinics and clinics.

Immediate versus delayed surgery for hip fractures in the elderly patients: a protocol for a systematic review and meta-analysis.

BACKGROUND: Hip fractures are a major public health problem in elderly populations and are accompanied by high-mortality rates. Whether timing of surgery has an impact on morbidity and mortality has been discussed controversially, numerous studies suggest that the delay of surgery can significantly increase the risk of morbidity and mortality; others report that achieving a stable medical condition is more important than early surgery. The goal of our systematic review is to assess the impact of timing of surgery on health outcomes in patients aged 60 years or older with acute hip fracture. In addition, we will investigate differences in beneficial or harmful effects of timing of surgery in subgroups of patients based on demographic characteristics, physical status, and the use of anticoagulant medications. METHODS: We will systematically search MEDLINE via Ovid, the Cochrane Library, Embase, PubMed, and clinical trial registries (from 1997 to 2017). In addition, we will search reference lists of pertinent reviews, archives of annual meetings of orthopaedic societies, and contact experts. We will include randomized controlled trials and non-randomized studies assessing the impact of timing of surgery after hip fracture in patients 60 years or older, published in English or German. Our outcomes of interest include health outcomes such as mortality, perioperative complications, functional capacity, and quality of life. We plan to perform meta-analyses if we have at least three sufficiently similar studies. If data are sufficient, we will conduct subgroup-analyses testing for differences between age groups, sex, patients' physical status as assessed with ASA (American Society of Anesthesiologists) scores, and the use of anticoagulation. DISCUSSION: Since this is the first systematic review on this topic since 2010, our findings will help to inform clinical practice guidelines concerning timing of surgery in hip fractures. Furthermore, our findings could contribute to define an optimal time period for surgery for different groups of patients with acute hip fracture. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2017 CRD42017058216.

The metaphyseal bone defect in distal radius fractures and its implication on trabecular remodeling-a histomorphometric study (case series).

BACKGROUND: The invention of the locking plate technology leads to alterations of treatment strategies at metaphyseal fracture sites with the concept of spontaneous remodeling of trabecular bone voids. Whereas trabecular regeneration has been proven in experimental animal studies, no histologic data exist on human fracture healing with special emphasis on bone voids. METHODS: In order to qualify the trabecular bone remodeling capacity in vivo, bone specimens from the metaphyseal bone void were analyzed 14 months after trauma using quantitative histomorphometry. Twenty-five patients with an unstable dorsally displaced distal radius fracture were fixed with a palmar locking plate without additional bone graft or substitute. At implant removal, specimens from the previous compression void were harvested with a trephine in a volar-dorsal direction. In 16 patients, histomorphometric analysis could be performed, comparing the dorsal trabecular network with the volar, non-compressed ultrastructure. RESULTS: Significant differences for bone volume/total volume (BV/TV), trabecular number (TbN) and trabecular separation (TbSp), but not for trabecular thickness (TbTh) and osteoid volume/total volume (OV/TV), were detected. Neither patient age, defect size nor gender had a significant influence on bone remodeling. CONCLUSIONS: The results of this study indicate that trabecular bone remodeling does not lead to pre-trauma bone quality in metaphyseal bone compression voids following reduction and application of a locking plate.