PURPOSE: The treatment and outcome of tibial stress fractures concomitant with knee osteoarthritis (OA) are complicated. The aim of this study was to evaluate the functional and radiological outcome of total knee arthroplasty with long tibial stem as a treatment for patients having knee OA and tibial stress fracture. METHODS: Patients who were diagnosed to have proximal tibia stress fracture along with knee OA at our institution between June 2013 and November 2018 were included in our study. All patients underwent total knee arthroplasty with long tibial stem. Preoperative and postoperative functional assessments were done according to range of movement of the knee joint, knee society score and knee injury and OA outcome score. Descriptive analysis was carried out by mean and standard deviation for quantitative variables, frequency and proportion for categorical variables. RESULTS: Twelve patients were included in the study. All patients were found to have stress fractures in the proximal half of tibia and extra-arthrosis. Four patients had non-union/delayed union, and 8 patients had acute fractures. The average preoperative range of movement was 88.1°, which improved to 116.3° at 3 months following surgery. It was found that the fracture has healed in all cases. Mean knee society score improved from 32.9 preoperatively to 89.3 at 1 year follow-up. Knee injury and OA outcome score improved from a mean score of 28.3 preoperatively to 81.1 at 1 year follow-up. CONCLUSION Stress fractures can occur in the proximal tibia in patients with knee OA. Total knee arthroplasty with tibial stem provides a suitable solution for both conditions. Additional plating or bone graft is unlikely to be required.
Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Osteoarthritis, Knee/surgery* ; Tibia/surgery* ; Fractures, Stress/surgery* ; Tibial Fractures ; Knee Joint ; Knee Injuries/surgery* ; Treatment Outcome

OBJECTIVE: To analyze the biomechanical mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures using finite element analysis (FEA). METHODS: Maxillofacial CT scans and temporomandibular joint (TMJ) MRI were performed on a young male with normal mandible, no wisdom teeth and no history of TMJ diseases. The three-dimensional finite element model of mandible was established by Mimics and ANSYS based on the CT and MRI data. The stress distributions of mandible with different angles of traumatic loads applied on the symphyseal region were analyzed. Besides, two models with or without disc, two working conditions in occlusal or non-occlusal status were established, respectively, and the differences of stress distribution between them were compared. RESULTS: A three-dimensional finite element model of mandible including TMJ was established successfully with the geometry and mechanical properties to reproduce a normal mandibular structure. Following a blow to the mandibular symphysis with different angles, stress concentration areas were mainly located at condyle, anterior border of ramus and symphyseal region under all conditions. The maximum equivalent stress always appeared on condylar articular surface. As the angle between the external force and the horizontal plane gradually increased from 0° to 60°, the stress on the mandible gradually concentrated to symphysis and bilateral condyle. However, when the angle between the external force and the horizontal plane exceeded 60°, the stress tended to disperse to other parts of the mandible. Compared with the condition without simulating the disc, the stress distribution of articular surface and condylar neck decreased significantly when the disc was present. Compared with non-occlusal status, the stress on the mandible in occlusal status mainly distributed on the occlusal surface, and no stress concentration was found in other parts of the mandible. CONCLUSION When the direction of external force is 60° from the horizontal plane, the stress distribution mainly concentrates on symphyseal region and bilateral condylar surface, which explains the occurrence of symphyseal fracture and intracapsular condylar fracture. The stress distribution of condyle (including articular surface and condylar neck) decreases significantly in the presence of arti-cular disc and in stable occlusal status when mandibular symphysis is under traumatic force.
Finite Element Analysis ; Humans ; Male ; Mandible ; Mandibular Condyle/diagnostic imaging* ; Mandibular Fractures/diagnostic imaging* ; Stress, Mechanical ; Temporomandibular Joint/diagnostic imaging* ; Temporomandibular Joint Disorders

A bone stress injury (BSI) means that the bones cannot tolerate repeated mechanical loads, resulting in structural fatigue and local bone pain. A delay in BSI diagnosis can lead to more serious injuries, such as stress fractures that require longer treatment periods. Therefore, early detection of BSI is an essential part of management. Risk factors for BSI development include biological and biomechanical factors. Medical history and physical examination are the basics for a BSI diagnosis, and magnetic resonance imaging is helpful for confirming and grading. In this paper, the authors review the overall content of BSI and stress fractures which are common in runners. Through this review, we hope that interest in stress fractures will be raised in Korea and that active researches will be conducted.
Diagnosis ; Fatigue ; Fractures, Stress ; Hope ; Korea ; Magnetic Resonance Imaging ; Physical Examination ; Risk Factors

Fracture is a common physical injury. Its healing process involves complex biological activities at tissue, cellular and molecular levels and is affected by mechanical and biological factors. Over recent years, numerical simulation methods have been widely used to explore the mechanisms of fracture healing, design fixators and develop novel treatment strategies, etc. This paper mainly recommend the numerical methods used for simulating fracture healing and their latest research progress, which helps people better understand the mechanism of fracture healing, and also provides direction and guidance for the numerical simulation research of fracture healing in the future. First, the fracture healing process and its relationship with mechanical stimulation and biological factors are described. Then, the numerical models used for simulating fracture healing (including mechano-regulatory model, biological regulatory model and mechano-biological regulatory model) and corresponding modeling techniques (mainly including agent-based techniques and fuzzy logic controlling method) were summarized in particular. Finally, the future research directions in numerical simulation of fracture healing were preliminarily prospected.
Computer Simulation ; Fracture Healing ; Fractures, Bone ; Humans ; Models, Biological ; Stress, Mechanical

Bilateral femoral neck stress fractures have been rarely reported. When diagnosed, they are usually limited to athletes or military personnel. A 35-year-old man, previously healthy, visited the emergency department for right inguinal pain. On physical examination, no external wound, tenderness or limitation of motion were found in either lower extremity. Plain radiography showed normal findings but an magnetic resonance image showed a linear fracture in the femoral neck. In this case, bilateral femoral neck stress fractures were found in a young non-athlete adult with no prior medical history of related injuries. Surgery is generally not performed for stress fractures but considering the patient's early mobilization and the need for quick reintegration into society, surgery was done in this case.
Adult ; Athletes ; Early Ambulation ; Emergency Service, Hospital ; Fatigue ; Femur Neck ; Femur ; Fractures, Stress ; Humans ; Lower Extremity ; Military Personnel ; Physical Examination ; Radiography ; Wounds and Injuries ; Young Adult

Biodynamics of mandibular angle fractures has been extensively discussed in the literature in search for the best way to fixate and expedite recovery of trauma patients. Pioneers like Michelet and Champy had the greatest impact on evolving of osteosynthesis in maxillofacial traumatology; they introduced their basic principles frequently used to describe the biomechanics of mandibular fixation. Their concept states when a physiologic load is applied on mandibular teeth a negative tension will be created at superior border and a positive pressure will appear at inferior border. These simple definitions are the basis for the advent of fixation modalities in mandibular angle fracture. This article sought to reassess these principals based on load location via finite elements method.
Biomechanical Phenomena ; Dental Stress Analysis ; Finite Element Analysis ; Fracture Fixation, Internal ; methods ; Humans ; Mandible ; physiopathology ; Mandibular Fractures ; physiopathology ; surgery ; Tooth ; physiology

OBJECTIVE: To introduce the design of customized pelvic prosthesis, to evaluate the biomechanical property under three load conditions of customized pelvic prosthesis under three load cinditions. METHODS: A titanium alloy prosthesis for reconstruction of pelvic tumors was designed by CAD software. The strength and stiffness of the custom prosthesis under static and slow gait conditions were analyzed and evaluated by finite element method. RESULTS: The results of the finite element analysis suggested that the maximum von Mises stress in the pelvic under three load conditions were 39.0, 202.8 and 42.4 MPa; the maximum displacement were 0.199, 0.766 and 0.847 mm. The maximum von Mises stress in the prosthesis under three load conditions were 62.3, 318 and 468 MPa. The maximum Von Mises stress in the Ti-alloy prosthesis and pelvic was far smaller than the yield strength of Ti-alloy. CONCLUSIONS The study can design the size and shape of prosthesis accurately according to patient's condition. The finite element method can reduce the bone stress level and fracture risk, prolong the service life of prostheses, and ensure the safety and stability of the postoperative patients under normal gait.
Biomechanical Phenomena ; Finite Element Analysis ; Fractures, Bone ; Gait ; Humans ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical

OBJECTIVE: To compare the clinical outcomes of microfracture and autogenous osteochondral mosaic transplantation in the treatment of knee joint cartilage injury. METHODS: A retrospective analysis of 71 patients with articular cartilage defects on the femoral condyles who were by autogenous osteochondral mosaic transplantation or microfracture from February 2011 to February 2016, and these patients were followed up for at least 2 years. According to the sugical procedures, the patients were divided into two groups. In the microfracture group, there were 33 patients, 20 males and 13 females, with a mean age of(28.1±4.2) years old; in the mosaicplasty group, there were 38 patients, 26 males and 12 females, with a mean age of(27.8±3.5) years old. The Lysholm knee score, Hospital for Special Surgery (HSS) knee score and the Ahlbäck classification grade were recorded to evaluate the clinical efficacy. Complications were also recorded. RESULTS: The mean Lysholm scores of the microfracture group and the mosaicplasty group improved from 62.9±6.8 and 60.3±7.5 preoperatively to 77.0±5.4 and 85.8±5.6 post-operatively, respectively(<0.05). Mean HSS scores of the microfracture group and the mosaicplasty group improved from 81.5±7.6 and 79.6±8.6 preoperatively to 88.0±4.7 and 91.9±4.7 post-operatively, respectively(<0.05). The mean Lysholm score and HSS score were significantly higher in the mosaicplasty group than those in the microfracture group at the latest follow-up. One patient in the mosaicplasty group suffered superficial wound infection. During the follow-up, no knee osteoarthritis was observed in two groups. CONCLUSIONS Autogenous osteochondral mosaicplasty and microfracture are proved to be safe and effective procedures for knee articular cartilage defects. However, the mosaicplasty has better clinical outcome than the microfracture.
Adult ; Cartilage, Articular ; Female ; Follow-Up Studies ; Fractures, Stress ; Humans ; Knee Joint ; Male ; Retrospective Studies ; Transplantation, Autologous ; Treatment Outcome ; Young Adult

OBJECTIVE: To explore the clinical effect of knee denervation combined with micro-fracture under arthroscope in the treatment of patellofemoral arthritis. METHODS: From May 2015 to May 2018, 60 patients with knee joint degenerative patellofemoral arthritis were treated, including 28 males and 32 females, aged from 24 to 56(40.5±3.35) years old. Among them, 30 cases underwent arthroscopic debridement alone(control group), 30 cases underwent arthroscopic debridement, peripatellar denervation combined with cartilage cone and patellofemoral articular surface microfracture treatment (treatment group). VAS, Lysholm and Kujala scores were used to evaluate the therapeutic effect. RESULTS: No complications such as wound infection, vascular nerve injury and deep venous thrombosis occurred in all patients. The patients were followed up for 7 to 36 months with an average of 12.5 months. The VAS scores of the two groups were improved 4 weeks after operation, and the improvement of the treatment group was significantly better than that of the control group, the difference was statistically significant (<0.05). Lysholm and Kujala scores were compared at the last follow-up of the two groups, the improvement of the treatment group was significantly better than that of the control group. CONCLUSIONS The treatment of patellofemoral arthritis with patellar denervation combined with microfracture can better relieve pain and improve knee function.
Adult ; Aged ; Arthritis ; Denervation ; Female ; Femur ; Fractures, Stress ; Humans ; Knee Joint ; Male ; Patella ; Patellofemoral Joint ; Treatment Outcome ; Young Adult

Acromial fractures are well-documented complications subsequent to reverse shoulder arthroplasty (RSA), and most appear as stress fractures with no history of single trauma. To date, no study has reported the occurrence of acute displaced acromial fracture due to sudden strong deltoid contraction during heavy work. Displacement of the fracture results in a challenging surgery since it is difficult to obtain adequate fixation in thin and osteoporotic bones. We report a rare case of acute displaced acromial fracture after successful RSA treatment, using a novel technique of open reduction and internal fixation, applying two 4.5 mm cannulated screws and lateral clavicle precontoured plate.
Acromion ; Arthroplasty ; Clavicle ; Fractures, Stress ; Scapula ; Shoulder