Scaphoid stress fracture is rare and occurs mainly in gymnasts. The current literature has only two reported cases: unilateral scaphoid stress fracture in a platform diver and bilateral scaphoid stress fracture in a gymnast. We herein report bilateral stress fracture of the scaphoid in a platform diver who presented with only one symptomatic side. Our patient was a 16-year-old competitive platform diver with an 18-month history of pain in the right wrist. Radiography revealed fracture of the right scaphoid at the waist. As part of our preoperative plan of measuring the scaphoid length to determine the appropriate screw, radiography of the contralateral side was performed, revealing an unexpected fracture of the left scaphoid. Due to the frequency of stress fractures in competitive sports, especially gymnastics, we recommend that bilateral scaphoid radiography be performed for athletes presenting with a unilateral scaphoid fracture, to avoid missing a fracture in the contralateral side.
Adolescent ; Diving ; injuries ; Fractures, Stress ; diagnostic imaging ; surgery ; Humans ; Male ; Radiography ; Scaphoid Bone ; injuries ; surgery

The presence of large segmental defects of the diaphyseal bone is challenging for orthopedic surgeons. Free vascularized fibular grafting (FVFG) is considered to be a reliable reconstructive procedure. Stress fractures are a common complication following this surgery, and hypertrophy is the main physiological change of the grafted fibula. The exact mechanism of hypertrophy is not completely known. To the best of our knowledge, no studies have examined the possible relationship between stress fractures and hypertrophy. We herein report three cases of patients underwent FVFG. Two of them developed stress fractures and significant hypertrophy, while the remaining patient developed neither stress fractures nor significant hypertrophy. This phenomenon indicates that a relationship may exist between stress fractures and hypertrophy of the grafted fibula, specifically, that the presence of a stress fracture may initiate the process of hypertrophy.
Adult ; Female ; Fibula ; pathology ; transplantation ; Fractures, Stress ; pathology ; Humans ; Hypertrophy ; Male ; Middle Aged ; Tibia ; surgery ; Tibial Fractures ; surgery

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

INTRODUCTION: In recent years, vascularized, i.e., living bone grafts, have been widely applied in the field of oral and maxillofacial surgery, as a method of treatment of congenital or acquired non-unions, and a large defects in mandible. The vascularized fibular graft has been especially used for this purpose because of its shape and mechanical strength. The postoperative hypertrophy of grafted fibula is of particular interest to us. MATERIAL AND METHODS: This study was undertaken to determine the volume change(indirect methods) and radiographic appearance of a free vascularized fibular graft as it responds to the mechanical and physiologic features of its new environment. In order to elucidate the long term effect on fibular mass after mandibular reconstruction, change in various method of volume change was utilized as indirect measure of change in long-term. RESULTS: The younger the patient, the more prominent and rapid the hypertrophy of the graft. the hypertrophy of the graft never exceeded the diameter of the recipient bone, except for callus enlargement after stress fracture of the grafted bone. CONCLUSION: Etiologic explanations for this phenomenon have not been clarified in the previeous literature. some of the factors implicated include a periosteal reaction or new bone formation, as seen at the onset of bone union after a fracture in a child, a reaction to the mechanical loading on the graft and a reaction to the circulatory changes resulting from the grafting procedure.
Bony Callus ; Child ; Fibula ; Fractures, Stress ; Humans ; Hypertrophy ; Mandible* ; Mandibular Reconstruction ; Osteogenesis ; Surgery, Oral ; Transplants

INTRODUCTION: In recent years, vascularized, i.e., living bone grafts, have been widely applied in the field of oral and maxillofacial surgery, as a method of treatment of congenital or acquired non-unions, and a large defects in mandible. The vascularized fibular graft has been especially used for this purpose because of its shape and mechanical strength. The postoperative hypertrophy of grafted fibula is of particular interest to us. MATERIAL AND METHODS: This study was undertaken to determine the volume change(indirect methods) and radiographic appearance of a free vascularized fibular graft as it responds to the mechanical and physiologic features of its new environment. In order to elucidate the long term effect on fibular mass after mandibular reconstruction, change in various method of volume change was utilized as indirect measure of change in long-term. RESULTS: The younger the patient, the more prominent and rapid the hypertrophy of the graft. the hypertrophy of the graft never exceeded the diameter of the recipient bone, except for callus enlargement after stress fracture of the grafted bone. CONCLUSION: Etiologic explanations for this phenomenon have not been clarified in the previeous literature. some of the factors implicated include a periosteal reaction or new bone formation, as seen at the onset of bone union after a fracture in a child, a reaction to the mechanical loading on the graft and a reaction to the circulatory changes resulting from the grafting procedure.
Bony Callus ; Child ; Fibula ; Fractures, Stress ; Humans ; Hypertrophy ; Mandible* ; Mandibular Reconstruction ; Osteogenesis ; Surgery, Oral ; Transplants

OBJECTIVETo investigate the mechanical characteristics of new type two-head automatic pressure external fixator in the view of biomechanics.

METHODSFifteen fresh and humid specimens were selected and divided into experimental group (5 cases) and control group (10 cases). The control group were respectively applied with DHS (5 cases) and traditional external fixator (5 cases). In order to compare the different apparatus, the strength, stiffness and twist mechanical function of femoral intertrochanteric fracture with different device were measured respectively when the specimens were under the pressure of 0-1800 N and loading speed 1.4 mn/min.

RESULTSThe strength, stiffness, twist mechanical function and maximum endurance of femora in the experimental group were obviously superior than that of DHS and traditional external fixator (P < 0.05).

CONCLUSIONTwo head automatic new type pressure external fixator can embed more tightly without sliding, also can prevent the occurrence of coxa vara effectively.

External Fixators ; Femoral Fractures ; surgery ; Fracture Fixation ; instrumentation ; methods ; Humans ; Stress, Mechanical

BACKGROUNDPrevious studies have suggested that percutaneous vertebroplasty might alter vertebral stress transfer, leading to adjacent vertebral failure. However, no three-dimensional finite element study so far accounted for the stress distributions on different cement volumes. The purpose of this study was to evaluate the stress distributions on the endplate under different loading conditions after augmentation with various volumes of bone cement.

METHODSL2-L3 motion segment data were obtained from CT scans of the lumbar spine from a cadaver of a young man who had no abnormal findings on roentgenograms. Three-dimensional model of L2-L3 was established using Mimics software, and finite element model of L2-L3 functional spinal unit (FSU) was established using Ansys10.0 software. For simulating percutaneous vertebral augmentation, polymethylmethacrylate (PMMA) was deposited into the bipedicle of the L2 vertebra. The percentage of PMMA volume varied between 15% and 30%. The stress distributions on the endplate of the augmented vertebral body were calculated under three different loading conditions.

RESULTSIn general, the stress level monotonically increased with bone cement volume. Under each loading condition, the stress change on the L2 superior and inferior endplates in three kinds of finite element models shows monotonic increase. Compared with the stress-increasing region of the endplate, the central part of the L2 endplate was subject to the greatest stress under three kinds of loading conditions, especially on the superior endplate and under flexion.

CONCLUSIONSThe finite element models of FSU are useful to optimize the planning for vertebroplasty. The bone cement volume might have an influence on the endplate of the augmentation, especially the superior endplate. It should be noted that the optimization of bone cement volume is patient specific; the volume of the bone cement should be based on the size, body mineral density, and stiffness of the vertebrae of individual patients.

Bone Cements ; therapeutic use ; Finite Element Analysis ; Humans ; Osteoporosis ; Spinal Fractures ; surgery ; Stress, Mechanical ; Vertebroplasty ; methods

BACKGROUNDOpen reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures.

METHODSA distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests.

RESULTSIn the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively.

CONCLUSIONSAnteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the anterolateral plating group. We can suggest that anteromedial plating is a clinically safe and effective way for humeral shaft fractures.

Biomechanical Phenomena ; Bone Plates ; Fracture Fixation, Internal ; Humans ; Humeral Fractures ; surgery ; Humerus ; surgery ; Models, Anatomic ; Stress, Mechanical

BACKGROUND: To characterize the recently issued femur shaft insufficiency fracture in terms of a patient's own epidemiological status. METHODS: Fourteen patients were treated for insufficiency fracture from July 2002 to June 2008, excluding cases including the risk factors of insufficiency fracture. All patients were female, and their mean age was 75.6 years (range, 65 to 89 years). The mean follow-up period was 50.6 months (range, 14 to 86 months). RESULTS: The mean body weight of the Koreans in the same age group was 58.1 +/- 9.7 kg, and the mean height was 155.5 +/- 8.8 cm. The mean body weight of our insufficiency fracture patients was 45.7 kg and it was statistically significantly lower than that of the Koreans in the same age group (p < 0.001). The mean height was 147.3 cm and it was significantly shorter than the mean height of the Koreans in the same age group (p = 0.002). In regard to menopausal time, the mean menopausal time of the Koreans was 48.0 +/- 4.2 years, it was 44 years in our study, as menopause occurred statistically significantly earlier (p = 0.017). The patients with insufficiency fracture showed statistically lower weight, shorter stature and an earlier menopausal period than that of the general population. CONCLUSIONS: In early menopausal, underweight, and short patients prescribed osteoporosis medication for an extended period of time, if predromal symptom is present, it is necessary to suspect insufficiency fracture of the femur.
Aged ; Aged, 80 and over ; Body Height ; Female ; Femoral Fractures/epidemiology/*pathology/surgery ; Femur ; Fractures, Stress/epidemiology/*pathology/surgery ; Humans ; Menopause ; Republic of Korea/epidemiology ; Risk Factors

OBJECTIVETo investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage.

METHODSEighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A, a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator.

RESULTSThe scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated.

CONCLUSIONSThe axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.

Animals ; Biomechanical Phenomena ; instrumentation ; methods ; External Fixators ; Fracture Fixation ; methods ; Fracture Healing ; physiology ; Fractures, Open ; surgery ; Rabbits ; Stress, Mechanical ; Tibial Fractures ; surgery