Heterotopic ossification (HO) is a known complication following total hip arthroplasty, with increased incidence in certain patient populations. Current prophylaxis options include oral non-steroidal anti-inflammatory drugs (NSAIDs) and radiation therapy, but an optimal radiation protocol has yet to be clearly defined. We performed a randomized, double-blinded clinical trial in high-risk total hip arthroplasty patients to determine the efficacy of 400 cGy versus 700 cGy doses of radiation. 147 patients at high risk for HO undergoing total hip arthroplasty (THA) at Rush-St. Luke's- Presbyterian medical center were randomized to either a single 400 cGy or 700 cGy dose of radiation. High risk was defined as diagnosis of diffuse idiopathic skeletal hyperostosis (DISH), hypertrophic osteoarthritis, ankylosing spondylitis, or history of previous heterotopic ossification. Radiation was administered over a 14 × 6 cm area of soft tissue and given on the first or second post-operative day. A blinded reviewer graded anterior-posterior (AP) and lateral radiographs taken immediately post-operatively and at a minimum of 6 months post-operatively. Progression was defined as an increase in Brooker classification from the immediate post-operative to the long-term post-operative radiograph. Operative data including surgical approach, use of cemented implants, revision surgery, and post-operative range of motion data were also collected.Background
Methods
The development of T-smart tomosynthesis has greatly improved the imaging quality of THA by reducing the peri-implant artifacts. In order to find out whether these improvements could lead to diagnostic advantages on stability of cementless THA arthroplasty components, we conducted a diagnostic research by comparing T-smart tomosynthesis, X-ray, and computed tomography. We retrospectively included 48 patients who undergone THA revisions in our center between Aug, 2013 and Mar, 2014. For patients with hybrid fixation as their primary prosthesis, the femoral or acetabular components with cement fixation were excluded. There were 41 cementless femoral stems and 35 cementless acetabular cups remained for evaluation. All patients took anterior-posterior and lateral view x-ray examination, anterior-posterior T-smart tomosynthesis scan, and computed tomography before revision surgery. As the gold standard, intraoperative pull-out tests and twisting tests were done for every patient to examine the stability of all implants. 7 orthopedic surgeons evaluated the preoperative images independently, who were divided into the senior group (3 doctors with 6∼13 years’ clinical experience) and the junior group (4 doctors with 2∼4 years’ clinical experience). The x-rays were evaluated first, followed by computed tomography 4 weeks later, and after another 4 weeks’ interval the T-smart tomosynthesis were assessed. All doctors used the same criteria for diagnosis. Diagnostic accuracy for each imaging examination was calculated by comparing with the results of intraoperative tests. The diagnostic accuracy, kappa values between 3 imaging techniques were calculated, and chi-square tests were conducted to examine the difference between the senior and junior groups for each technique.Background
Methods
We compare the difference in expression profiles of miRNAs during fracture healing between adult and aged female mice. This study reveals the possibility to improve impaired fracture healing in aged females by regulating key miRNAs at early stage. Impaired fracture healing in aged female skeleton is still a clinical challenge (Holroyd et al., Summary
Introduction
The mechanism of spinal cord injury varies across the human population and this may be important for the development of effective therapies. Therefore, detailed understanding of how variables such as impact velocity and depth affect cord tissue damage is important. Studies have shown an independent effect of impact velocity and depth on injury severity, thereby suggesting importance of the interaction between the two for spinal cord injury. This work examines both the individual and interactive effects of impact velocity and impact depth on demyelination, tissue sparing, and behavioural outcomes in the rat cervical spinal cord. It also aims to understand the contribution of the energy applied during impact, not only the impact factors. Decoupling the effects of these two impact parameters will help to describe the injury mechanism. Maximum principal strain has also been shown to be useful as a predictor for neural tissue damage in vivo and in finite element (FE) models. A better understanding of this relationship with experimental results may help to elucidate the mechanics of spinal cord injury.Summary Statement
Introduction
While indications for total knee (TKA) and hip arthroplasty (THA) have expanded over the last 35 years, implant labeling has largely remained stagnant, with conditions including obesity, developmental dysplasia, and many others (Table 1) still considered as contraindications. Implant labeling has not co-evolved with surgical indications, as most orthopaedic implants are cleared through the 510(k) process, which conserves the labeling of the predicate device. While surgeons can legally use devices for off-label indications, the scrutiny regarding off-label use of orthopaedic implants has intensified. The objective of this study was to determine the incidence of off-label use at our institution, define the risk in terms of revision rate associated with off-label use, and to compare activity level, functional outcomes, and general health outcomes for on- and off-label TKA and THA patients. Patients who underwent primary TKA or THA at a large academic tertiary referral center between January 1, 2010 and June 30, 2010 were considered for the study (n = 705). Of this cohort, a convenience sample of 283 patients were selected for the study based on the presence of baseline outcomes data. Patients were contacted via mail and/or phone to collect details regarding potential revision surgeries, UCLA activity scores, short form-12 (SF-12), Knee Injury and Osteoarthritis Outcome Score (KOOS) or Hip Disability and Osteoarthritis Outcome Score (HOOS). Using labeled contraindications from the product inserts from multiple orthopaedic implant manufacturers, procedures were categorized as on-label or off-label. Outcomes including revision rate, activity score, and SF-12, KOOS, and HOOS scores were adjusted for age, gender, and BMI by fitting a logistic model and analyzed using the Wald chi-square test (SPSS, Chicago, IL).Introduction:
Methods:
Spinal cord damage was compared after an injury was inflicted by three clinically relevant mechanisms (contusion, dislocation, and distraction). A novel SCI multi-mechanism system has been developed. Central hemorrhage was common to all mechanisms. Increased membrane permeability was localized to the injury epicenter in contusion but spread further in distraction. Dislocation showed intermediate characteristics exhibiting both local neuronal losses at the epicenter and extended regions of membrane permeability. These preliminary observations suggest that distinct injury mechanisms result in differences in the primary damage of the spinal cord. This work compared primary damage after spinal cord injury (SCI) inflicted by three clinically relevant mechanisms. Different injury mechanisms result in regional differences in damage to the spinal cord. Differences in acute damage may help guide targeted therapies following SCI. At greater distances from the lesion, dextran was excluded from neuronal somata and in the white matter only distinct accumulation was seen at the Nodes of Ranvier. At the injury site, hemorrhage was common to all mechanisms although more diffuse in the distraction injuries. Increased membrane permeability was localized to the injury epicenter in contusion but spread further in distraction. Dislocation showed intermediate characteristics exhibiting both local neuronal losses at the epicenter and extended regions of permeability. A novel SCI multi-mechanism system was developed which uses an electromagnetic actuator to permit the modeling of injuries along any direction. Dextran was infused into the cisterna magna 1.5 to 2 hours prior to injury in order to visualize increases in membrane permeability. Stereotaxic clamps were designed to rigidly hold the lower cervical vertebrae of deeply anaesthetized rats permitting displacements at speeds of 100cm/s. A range of displacements was used in this pilot series: 0.9 to 1.1mm contusion, 2 to 6mm dislocation and 3 to 8mm axial distraction. Animals were sacrificed at five minutes in order to analyse the primary injury. These preliminary observations suggest that distinct injury mechanisms result in regional differences in the primary damage of spinal cord gray and white matter.
A one-year-8-month-old girl who received radiotherapy and chemotheraphy after excision of embryonal rhabdomyosarcoma from left labium majus pudendi developed slipped capital femoral epiphysis (SCFE) over right hip when she was 9 years old. After mild limp had been noted for 6 months she was then referred to pediatric orthopedic surgeon and two Knowles pins were used to fix the slipping. The second case was a 17-year-old girl with Turner syndrome. SCFE developed during the growth hormone therapy and it was treated with percutaneous pinning with two cannnulated screws. The possibility of developing SCFE should always be kept in mind when treating and following these particular cases to avoid delay of diagnosis.
We studied the origin of the anterior deltoid from the lateral third of the clavicle and the leading anterior edge of the acromion in 18 cadaver shoulders by anatomical and histological methods. The main origin of the deltoid was from the superior surface of the anterior acromion, but muscle and tendinous attachments were also seen on the entire anterior surface of the acromion, its anteroinferior surface and on the whole width of the anterior surface of the clavicle. Mock arthroscopic acromioplasty was shown to detach deltoid fibres from the anterior surfaces, leaving the superior attachment in continuity. Potentially, arthroscopic subacromial and clavicular resection can detach deltoid fibres originating from the anterior and anteroinferior surfaces of the acromion and clavicle and thus weaken the anterior deltoid.
