There are concerns regarding nail/medullary canal mismatch and initial stability after cephalomedullary nailing in unstable pertrochanteric fractures. This study aimed to investigate the effect of an additional anteroposterior blocking screw on fixation stability in unstable pertrochanteric fracture models with a nail/medullary canal mismatch after short cephalomedullary nail (CMN) fixation. Eight finite element models (FEMs), comprising four different femoral diameters, with and without blocking screws, were constructed, and unstable intertrochanteric fractures fixed with short CMNs were reproduced in all FEMs. Micromotions of distal shaft fragment related to proximal fragment, and stress concentrations at the nail construct were measured.Aims
Methods
Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis. After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy. Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve. Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment. Cite this article:
This paper aims to analyze the kinetics of the over-ground wheel-type body weight supporting system (BWS); tendency changes of low extremity joint moment (hip, knee, ankle), 3 axis accelerations of a trunk, cadence and gait velocity as weight bearing level changes. 15 subjects (11 males, 4 females, age:23.63.5, height:170.65.1cm, weight:69.0210.75kg) who had no history of surgery participated. 6 levels (0%, 10%, 20%, 30%, 40% and 50%) of BWS were given to subjects at self-selected gait velocity and kinetic data was calculated using a motion capture system, Vicon® (Vicon, UK).Objective
Method
Venous thromboembolism (VTE), including pulmonary embolism (PE) resulting from deep vein thrombosis (DVT), remains a well-known serious complication after femoral fractures. The low molecular heparin is widely used to prevent VTE. This study compared the effectiveness of VTE prevention between dalteparin and enoxaparin. From 2013 to 2014, we retrospectively recruited 712 patients who had femoral fractures with operative treatment. All patients receiving VTE chemoprophylaxis with perioperative period using dalateparin in Group 1(N=395) and enoxaparin in Group 2(N=317). The prophylactic dosing was determined using individual product labeling and identified as enoxaparin 40 mg every 12 hours and dalteparin 2500 international unit (IU) once daily, based on clinical practice guidelines. The prophylaxis was started at admission, and maintained during average 8.43.5 days after operation. The outcome including the incidence of clinically significant deep vein thrombosis, pulmonary embolism, perioperative bleeding and cost of drugs were evaluated between two groups.Introduction
Materials and Methods
There has not been a comparison of patients and outcomes between two separate countries for any knee prosthesis. This study compares total knee replacement outcomes between an Indonesian and American cohort. We aim to compare the clinical results between two different hospitals in two different countries using post-operative range of motion as the primary clinical result. 177 Indonesian RPF TKR patients were compared to 84 American patients. Demographics, patient recorded outcomes scores (KSS, PAQ, WOMAC), flexion, and component size were compared between the groups. Standard t-test was used to compare the variables between the two countries and regression analysis adjusting for age, BMI, length of follow-up, sex, preoperative WOMAC and PAQ score, preoperative KSS knee score, preoperative KSS function score, and preoperative UCLA was used to compare outcomes.Introduction
Materials and Methods
The use of open wedge high tibial osteotomy (OWHTO) to reduce knee pain by transferring weight-bearing loads to the relatively unaffected lateral compartment in varus knees and to delay the need for a knee replacement by slowing or stopping destruction of the medial joint compartment. To maintain the stability of OWHTO, the most common type of plate was T-Plate as the locking compression plate (LCP) concept. Anterior portion of T-Plate infringe patient's soft tissue resulted in some complications, whereas anatomical L-plate does not. To evaluate the structural stability of the anatomically contoured L-plate in the present study, the effect of weight bearing after osteotomy should be reviewed in the point of the stress of the plate and screws. We hypothesize that its stress path diverge through collateral portion of tibia and the stress level in screws lowered comparing to the result of T-plate presented in existing literature. Based on the postoperative CT data were made from the reconstruction model for finite-element model. The value of Young's modulus and Poisson's ratio were 17,000MPa and 0.36 for cortical bone and 300MPa and 0.3 for cancellous bone. The anatomically contoured L-Plate system, the material of all plate systems were surgical Ti-Alloy were homogeneous and linear properties (Young's modulus = 113,000MPa, Poisson's ratio = 0.33). The screw system were the same as the material properties of the anatomically contoured L-Plate system. For finite element analysis, both the bone and screws were contacted as general condition. And the screws and plate were contacted as tie contact(Figure 1). The load conditions were applied to the top of the tibia based physiological (=1400N) and surgical loads (=200N). In this study, the compressive-bending load was applied to the two nodal points corresponding to the centers of each tibial condyle and divided into 60% and 40% to the medial and lateral sides, respectively. The physiological loads applied in the quadrant section on the proximal tibia.(Chu-An Luo, 2013)Introduction
Materials and Methods
Open-wedge high tibial osteotomy (OWHTO) is an operation involving proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. Therefore, stable fixation is mandatory for safe healing of this additive type of osteotomy to minimize the risk of non-union and loss of correction. For stability, screws provide optimal support and anchorage of the fixator in the condylar area without risking penetration of either the articulating surface. The purpose of the study was to evaluate the screw insertion angle and orientation with an anatomical plate that is post-contoured to the surface geometry of the proximal tibia after OWHTO. From March 2012 to June 2014, 31 uni-planar and 38 bi-planar osteotomies were evaluated. Postoperative computed tomography data obtained after open wedge high tibial osteotomy using a locking plate were used for reconstruction of the 3 dimensional model with Mimics v.16.0 of the proximal tibia and locking plate. Measurement data were compared between 2 groups (gap lesser than or equal to 10 mm (Group 1) and gap greater than 10 mm(Group 2)). These data were also compared between the uniplanar (Group 3) and bi-planar (Group 4) osteotomy groups.Background
Methods
Although thigh pain is an annoying problem after total hip arthroplasty (THA), little information has been known about its natural course. To determine the frequency, time of onset, and duration of thigh pain after cementless THA, we evaluated 240 patients (240 hips) who underwent primary THA because of femoral head osteonecrosis with the use of a single tapered stem.Background
Methods
The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.Objectives
Methods
Open wedge high tibial osteotomy (OWHTO) is an operation by the proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. However, for the proper load re-distribution, stable fixation is mandatory. For the stable fixation, plate should be contoured to the bony surface and screws should be inserted from the central area of the medial side to the hinge area of the lateral side in the proximal fragment because most failures occur at the relatively lesser supported lateral hinge area. Therefore, the purpose of this study was to evaluate the screw insertion angle and orientation that is inserted to the direction of the lateral hinge with an anatomical plate that is post-contoured with a surface geometry of the proximal tibia after the OWHTO. The hypothesis of this study was that the position and orientation would be different according to the correction degree (median value 10 mm) and surgical technique (uni-planar vs bi-planar). Thirty-one uni-planar and thirty-eight bi-planar osteotomies were evaluated. Postoperative CT data obtained after OWHTO were used for the 3D reconstruction of the proximal tibia. Anterior dimension (L1) and posterior dimension (L2) of the proximal tibia were measured in sagittal plane from tibial spine. Screw insertion points using four holes were even distributed using L1 and L2 value. As screw insertion angle was set from four holes to lateral hinge of the ‘Safe Zone’. Those four angles were measured in the axial and coronal plane. These were compared according to the correction degree and surgical technique.Introduction
Materials and Methods
Acetabular component position is considered a major factor affecting the etiology of hip dislocation. The ‘Lewinnek safe zone’ has been the most widely accepted range for component position to avoid hip dislocation, but recent studies suggest that this safe zone is outdated. We used a large prospective institutional registry to ask: 1) is there a ‘safe zone’ for acetabular component position, as measured on an anteroposterior radiograph, within which the risk of hip dislocation is low?, and 2) do other patient and implant factors affect the risk of hip dislocation? From 2007 to 2012, 19,449 patients (22,097 hip procedures) were recorded in an IRB approved prospective total joint replacement registry. All patients who underwent primary THA were prospectively enrolled, of which 9,107 patients consented to participate in the registry. An adverse event survey (80% compliance) was used to identify patients who reported a dislocation event in the six months after hip replacement surgery. Postoperative AP radiographs of hips that dislocated were matched with AP radiographs of stable hips, and acetabular position was measured using Ein Bild Röntgen Analyse software. Dislocators in radiographic zones (± 5°, ± 10°, ± 15° boundaries) were counted for every 1° of anteversion and inclination angles.Introduction
Materials and Methods
In comminuted intertrochanteric fractures, various operative options have been introduced. The purpose of this study was to determine whether there were differences in clinical and radiologic outcomes among bipolar hemiarthroplasty(BH), compression hip screw(CHS) and proximal femur nail antirotatory(PFNA) in treating comminuted intertrochanteric fractures(AO type, A2(21, 22, 23)) We retrospectively evaluated total 150 patients(BH:50, CHS:50, PFNA: 50) who were operated due to intertrochanteric fractures from March 2010 to Dec 2012 and were older than 65 years at the time of surgery. We compared these three groups for radiologic and clinical outcomes at 12 months postoperatively, including Harris hip score, ability of ambulation(Koval stage), visual analogue scale and radiologic limb length discrepancy(shortening). Landmark and radiologic length was checked.
–A: postoperative length –A’: POD 1year –B: immediate posteopative contralateral length(from hip center to distal tip of lesser trochanter) –B’: POD 1year contralateral length(from hip center to distal tip of lesser trochanter) –
Limb length(shortening) was adjusted considering difference of magnification = {A × (B’/B)}− A’Introduction
Materials and Methods
Historically, the outcomes of knee replacement were evaluated based on implant longevity, major complications and range of motion. Over the last recent years however, there has been an intensively growth of interest in the patient's perception of functional outcome. However, the currently used patient related outcome (PRO) scores are limited by ceiling effects which limit the possibility to distinguish between good and excellent results post knee arthroplasty. The Forgotten Joint Score (FJS) is a new PRO score which is not influenced by ceiling effects, therefore making it the ideal instrument to compare functional outcome between various types of implants. It is based on the thought that the ultimate goal in joint arthroplasty is the ability of a patient to forget their artificial joint in everyday life. The aim of this study is to compare the FJS between patients who undergo TKA and patients who undergo medial UKA at least 12 months post-operatively. We hypothesized that the UKA which is less extensive surgical procedure will present better FJS than TKA, even 12 month postoperative. All patients who underwent medial UKA or TKA were contacted 12 months post-operatively. They were asked to complete the FJS, the Western Ontario and McMasters Universities Osteoarthritis index (WOMAC) and the EuroQol-5D (EQ-5D). A priori power analysis was conducted using two-sample t-test. 64 patients in each group were needed to reach 80% power for detecting a 12 point (SD 24) significant difference on the FJS scale with a two-sided significant level of 0.05. A p-value <0.05 was considered as statistically significant.Introduction
Methods
Two-stage reconstruction, reimplantation after removal of an infected prosthesis, has been considered to be the gold standard for treatment of infected hip arthroplasty. However, during the removal of a well-fixed femoral stem, the proximal femur can be damaged and a sequestrum can be formed, which might lead to chronic osteomyelitis and difficulty in reimplantation. We wanted to determine whether infection after hip arthroplasty can be treated without removal of a well-fixed stem. We treated 19 patients who had an infection after hip replacement, but a well-fixed cementless stem, with 2-stage reconstruction. At the first stage, we removed the acetabular cup, the liner and the head, but not the stem. We then implanted a cup of cement spacer. After control of infection, we reimplanted the acetabular component and head.Background:
Materials and Methods:
Pre-operative planning for total hip replacement
(THR) is challenging in hips with severe acetabular deformities, including
those with a hypoplastic acetabulum or severe defects and in the
presence of arthrodesis or ankylosis. We evaluated whether a Rapid
Prototype (RP) model, which is a life-sized reproduction based on
three-dimensional CT scans, can determine the feasibility of THR
and provide information about the size and position of the acetabular component
in severe acetabular deformities. THR was planned using an RP model
in 21 complex hips in five men (five hips) and 16 women (16 hips)
with a mean age of 47.7 years (24 to 70) at operation. An acetabular
component was implanted successfully and THR completed in all hips.
The acetabular component used was within 2 mm of the predicted size
in 17 hips (80.9%). All of the acetabular components and femoral
stems had radiological evidence of bone ingrowth and stability at
the final follow-up, without any detectable wear or peri-prosthetic
osteolysis. The RP model allowed a simulated procedure pre-operatively
and was helpful in determining the feasibility of THR pre-operatively,
and to decide on implant type, size and position in complex THRs. Cite this article:
We investigated the spinopelvic morphology and
global sagittal balance of patients with a degenerative retrolisthesis
or anterolisthesis. A total of 269 consecutive patients with a degenerative
spondylolisthesis were included in this study. There were 95 men
and 174 women with a mean age of 64.3 years ( A backward slip was found in the upper lumbar levels (mostly
L2 or L3) with an almost equal gender distribution in both the R
and R+A groups. The pelvic incidence and sacral slope of the R group
were significantly lower than those of the A (both p <
0.001)
and R+A groups (both p <
0.001). The lumbar lordosis of the R+A
group was significantly greater than that of the R (p = 0.025) and
A groups (p = 0.014). The C7 plumb line of the R group was located
more posteriorly than that of the A group (p = 0.023), but was no
different from than that of the R+A group (p = 0.422). The location
of C7 plumb line did not differ between the three groups (p = 0.068).
The spinosacral angle of the R group was significantly smaller than
that of the A group (p <
0.001) and R+A group (p <
0.001). Our findings imply that there are two types of degenerative retrolisthesis:
one occurs primarily as a result of degeneration in patients with
low pelvic incidence, and the other occurs secondarily as a compensatory
mechanism in patients with an anterolisthesis and high pelvic incidence. Cite this article:
Metal-on-metal (MOM) hip joints have regained a favor in arthroplasty since they own excellent wear resistance. In this study, wear tests by using a hip joint simulator were conducted with MOM bearings of specified 40 mm femoral heads. The influence of clearance on the wear behavior was investigated. Furthermore, an optimized radial clearance was estimated by lubricant film thickness and contact pressure analysis. Co-27Cr-5Mo-0.13N-0.05C (hereafter CCMN) alloy (mass %) was used. The ingots were vacuum induction melted, homogenized and hot forged successively. The microstructure shows equiaxed crystal grains with abundant annealing twins but no carbides. Two groups of bearings, indicated as The contact pressures on the hip joints were also analyzed by using ABAQUS. The femoral heads were set 40 mm with radial clearances of 0–200 μm. Half models were set up and only the maximum force of 3 kN converted as pressure was applied as boundary condition.Introduction
Materials and methods
Rapid manufacturing using laser beam and/or electron beam has been applied to fabrication of artificial hip and knee joints in quite recent years. In the electron beam melting (EBM) method, the high energy electron beam effectively melts the metal powder without creating flaws such as porosities or inclusions of oxide particles during building. Thus it is found that EBM technique for rapid manufacturing of artificial hip and knee joints processes a higher possibility as the next-generation methodology for fabrication of the medical devices such as hip and knee joints. In the present study, we focus on the EBM technique. The microstructures and mechanical properties of Co-29Cr-6Mo alloy with C and N additions, produced by using EBM method, were studied using X-ray diffraction, electron back scatter diffraction, transmission electron microscope (TEM), Vickers hardness tests, and tensile tests, focusing on the influences on the build direction and the various heat treatments after build. It is found that the microstructures for the as built specimens were changed from columnar (Fig. 1a) to eqiaxed grain structure (Fig. 1c) with average grain size of approximately 10–20 μm due to the heat treatment employing the reverse transformation from a lamellar (hcp + Cr2N) phase to an fcc phase. Our results will contribute to the development of biomedical Ni-free Co–Cr–Mo–N-C alloys, produced by EBM method, with refined grain size and good mechanical properties, without requiring any hot workings. Fig. 1 Inverse pole figure (IPF) maps of microstructure of samples produced by EBM method, taken by EBSD. (a) as-built, (b) after aging treatment, (c) after reverse transformation heat treatment (RT-HT).
This prospective multicentre study was undertaken
to determine whether the timing of the post-operative administration
of bisphosphonate affects fracture healing and the rate of complication
following an intertrochanteric fracture. Between August 2008 and
December 2009, 90 patients with an intertrochanteric fracture who
underwent internal fixation were randomised to three groups according
to the timing of the commencement of risedronate treatment after
surgery: Group A (from one week after surgery), Group B (from one
month after surgery), and Group C (from three months after surgery).
The radiological time to fracture healing was assessed as the primary
endpoint, and the incidence of complications, including excessive
displacement or any complication requiring revision surgery, as
the secondary endpoint. The mean time to fracture healing post-operatively
in groups A, B and C was 10.7 weeks ( This study demonstrates that the timing of the post-operative
administration of bisphosphonates does not appear to affect the
rate of healing of an intertrochanteric fracture or the incidence
of complications.
Co-Cr-Mo alloys are widely used for biomedical implant materials such as artificial hip and knee joints owing to their excellent corrosion and wear resistance as well as higher strengthening properties. However, the alloys exhibits sever brittle nature under an as-cast condition. It is generally recognized that refinement of the grain size of the metallic materials by means of hot-forging processes is an effective methodology to strengthen the alloy. Dynamic recrystallization (DRX) is an effective metallurgical process for grain refinement during hot deformation. However, there are few studies on the hot deformation behavior of Co-Cr-Mo alloy, especially grain refinement through DRX. In the present study, DRX and grain refinement during hot deformation of Co-29Cr-6Mo alloy has been investigated under various conditions such as deformation temperature and strain rate. Although at strain of 5% hot deformed microstructure maintains the original grains, the grain size decreases with increasing the strain and exhibits the average grain size of approximately 2μm at strain of 60%. Ultra fine grained microstructure with the grain size of approximately 0.5 μm was obtained under deformation at a 1323 K at a strain rate of 0.1s-1. The original grains are broken up into different grains due to the new boundary formation not only near the initial boundaries but also in the interior of the grains at large strain. This grain fragmentation without bulging in the course of hot deformation is associated with considerably low stacking fault energy (SFE) of the Co-29Cr-6Mo alloy even at the deformation temperatures.
