bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Factors for Periprosthetic Joint Infection in Total Knee Arthroplasty
Authors: Lee Qunn Jid , Mak Wai Ping , Wong Yiu Chung 
Published: October 2016

Purpose. To evaluate the incidence and risk factors of periprosthetic joint infection (PJI) in patients undergoing total knee arthroplasty (TKA) in a high-volume hospital. Methods. Records of 1133 primary TKAs were reviewed. Correlation between surgery volume and infection rate was determined. Risk factors for PJI were identified using case-control analysis of variables. TKAs performed between October 2012 and March 2013 without infection were used as controls. Results. Of 1133 TKAs, 8 (0.71%) PJI occurred. The organisms involved were Staphylococcus aureus (n=4), coagulase-negative staphylococci (n=2), Pseudomonas aeruginosa (n=1), and methicillin-resistant S aureus (n=1). In the 6-month period chosen as the control period, one (0.52%) out of 192 TKAs developed PJI. Hospital annual volume did not correlate with infection rate (p=0.766). Significant risk factors included young age, comorbidities such as diabetes, anaemia, thyroid disease, heart disease, lung disease, and long operating time. Six of the 8 patients with PJIs had at least one risk factor. However, the number of patients with infection was too small to have sufficient power. Conclusion. Comorbidities are a risk factor for PJI. Perioperative optimisation of comorbidities and the use of antibiotic-loaded cement in patients with severe comorbidities should be considered.
Epidural versus Intra-Articular Infusion Analgesia following Total Knee Replacement
Authors: Kasture Sarang , Saraf Hrushikesh 
Published: October 2016

Purpose. To compare the efficacy of epidural versus intra-articular infusion analgesia following total knee replacement (TKR). Methods. 25 men and 50 women aged 55 to 75 (mean, 67) years who underwent primary TKR by a single surgeon were randomised and consented to receive either epidural (n=35) or intra-articular (n=40) infusion analgesia for 48 hours at 5 ml/hr. All patients also received intravenous aqueous diclofenac 50 mg twice a day. Patients were assessed 6 hourly for visual analogue score (VAS) for pain to determine the analgesic effect. Complications such as paraesthesia in the lower limbs, hypotension, urinary retention, and abdominal distension were recorded, as was the rehabilitation progress with respect to the time to stand, climb stairs, use of commode chair, and discharge. Results. The epidural and intra-articular infusion groups were comparable with respect to age, sex, weight, and operating time, as was the analgesic efficacy within 48 hours of TKR. Patients with epidural infusion analgesia had a higher complication rate in terms of hypotension (51.4% vs. 22.5%, p=0.015) and troublesome paraesthesia in the lower limbs (45.7% vs. 12.5%, p=0.028), and a trend of higher abdominal distension rate (20% vs. 5%, p=0.073). Patients with intra-articular infusion analgesia were able to stand/walk earlier (2.08 vs. 2.54 days, p<0.001). The 2 groups did not differ significantly in the time needed to climb stairs, use of commode chair, and discharge. Conclusion. The efficacy of epidural and intra-articular infusion analgesia was comparable. Intra-articular infusion was associated with fewer complications and earlier rehabilitation.
Early versus Late Surgery for Closed Ankle Fractures
Authors: Singh Rohit Amol , Trickett Ryan , Hodgson Paul 
Published: October 2016

Purpose. To compare the outcome after early versus late surgery for closed ankle fractures in terms of the length of hospital stay and infection rate. Methods. Records of 95 men and 119 women aged 14 to 92 (mean, 46) years who underwent open reduction and internal fixation for ankle fractures during three 6-month periods in 2004, 2007, and 2010 were reviewed. 82 and 132 patients underwent surgery <24 hours and >24 hours after presentation, respectively. The most common reason for delayed surgery was unavailability of the operation theatre, followed by delayed admission to the fracture clinic and excess soft tissue swelling. Results. Patient and injury characteristics of the 3 study periods were comparable (p=0.399). The early and late surgery groups were comparable in proportions of various fracture patterns but not in patient age (40 vs. 49 years, p=0.002). The mean postoperative length of hospital stay was shorter in the early surgery group (2.9 vs. 5.5 days, p=0.009). The 2 groups did not differ significantly in the infection rate (7% vs. 11%, p=0.589) or the need for additional surgery (3.7% vs. 5.3%, p=0.63). Conclusion. Patients with delayed surgery for ankle fracture had a longer postoperative length of hospital stay. Surgery should be performed within 24 hours of injury to minimise the length of hospital stay.
A Kirschner Wire as a Transverse-Axis Guide to Improve Acetabular Cup Positioning
Authors: Ishidou Yasuhiro , Hirotsu Masataka , Setoguchi Takao , Nagano Satoshi , Kakoi Hironori , Yokouchi Masahiro , Yamamoto Takuya , Komiya Setsuro 
Published: October 2016

Purpose. To compare cup-positioning accuracy in total hip arthroplasty (THA) with or without use of a Kirschner wire as a transverse-axis guide for pelvic alignment. Methods. Records of 18 men and 73 women (mean age, 60 years) who underwent primary THA with (n=49) or without (n=42) use of a Kirschner wire as a transverse-axis guide for pelvic alignment were reviewed. A 2.4-mm Kirschner wire as a transverse-axis guide was inserted to the anterior superior iliac spine and was parallel to a line linking the left and right anterior superior iliac spine. The safe zone for cup positioning was defined as 30° to 50° abduction and 10° to 30° anteversion. Of the 5 operative surgeons, 2 were classified as experienced (total surgical volume >300) and 3 as inexperienced (total surgical volume of <50). The proportion of patients with the cup in the safe zone was compared in patients with or without use of the transverse-axis guide and in experienced and inexperienced surgeons. Results. For inexperienced surgeons, the use of the transverse-axis guide significantly improved the proportion of patients with the cup in the safe zone from 90% to 100% for abduction, from 50% to 82.4% for anteversion, and from 40% to 82.4% for both. Patients with the cup inside or outside the safe zone were comparable in terms of body height, weight, BMI, subcutaneous fat thickness, incision length, and acetabular cup size. Conclusion. The use of the transverse-axis guide improved the accuracy of cup positioning by inexperienced surgeons.
A Binaural Grouping Model for Predicting Speech Intelligibility in Multitalker Environments
Authors: Mi Jing , Colburn H. Steven 
Published: October 2016

Spatially separating speech maskers from target speech often leads to a large intelligibility improvement. Modeling this phenomenon has long been of interest to binaural-hearing researchers for uncovering brain mechanisms and for improving signal-processing algorithms in hearing-assistive devices. Much of the previous binaural modeling work focused on the unmasking enabled by binaural cues at the periphery, and little quantitative modeling has been directed toward the grouping or source-separation benefits of binaural processing. In this article, we propose a binaural model that focuses on grouping, specifically on the selection of time-frequency units that are dominated by signals from the direction of the target. The proposed model uses Equalization-Cancellation (EC) processing with a binary decision rule to estimate a time-frequency binary mask. EC processing is carried out to cancel the target signal and the energy change between the EC input and output is used as a feature that reflects target dominance in each time-frequency unit. The processing in the proposed model requires little computational resources and is straightforward to implement. In combination with the Coherence-based Speech Intelligibility Index, the model is applied to predict the speech intelligibility data measured by Marrone et al. The predicted speech reception threshold matches the pattern of the measured data well, even though the predicted intelligibility improvements relative to the colocated condition are larger than some of the measured data, which may reflect the lack of internal noise in this initial version of the model.
Anatomical Lateral and Medial Ligament Reconstruction in Rotational Chronic Ankle Instability
Authors: Wiewiorski Martin J. , Alrashidi Yousef , Stelzenbach Christian , Herrera-Perez Mario , Barg Alexej , Valderrabano Victor 
Published: October 2016

Category: Sports. Introduction/Purpose: Rotational (combined lateral and medial) chronic ankle instability (CAI) can present with pain and tenderness at the ankle joint, and can be associated with feeling of giving way, repetitive sprains, and life quality limitation. In case of surgery, anatomical reconstruction of the ligaments and treatment of comorbidities are essential for a solid outcome. Methods: A retrospective chart review of 81 rotational CAI patients (average age: 35.3 years, age range: 16-64; right sided: 41(50.6%); left sided: 40(49.4%)) was performed. The average latest follow-up visit was 10.8 months (range: 3-47 months). The patients underwent in our center a standardized surgical treatment protocol. Following diagnostic ankle arthroscopy, a combined lateral and medial anatomical ligament reconstruction was performed. Hindfoot realignment procedures and treatment of associated pathologies (such as talar osteochondral lesions) were carried out at the same time. Postoperatively, all patients were mobilised with partial weight bearing (15 kg) for six weeks in an Aircast walker ® (DJO, LLC, USA). Adequate postoperative analgesia and physiotherapy were initiated. Results: Combined lateral and medial ligament reconstruction without additional surgeries was performed in 20 cases (24.7%). In the other cases, to address associated pathologies, additional surgeries were performed, such as: lateral calcaneal lengthening osteotomy (LCLO) in 42 cases (51.9%), medial sliding calcaneal osteotomy (MSCO) in 3 Cases (3.7%), osteochondral lesion reconstruction in 20 cases (24.7%), peroneal tendon pathology treatment in 3 cases (3.7%), cavovarus foot correction in 1 case (1.2%), supramalleolar osteotomy in 1 case (1.2%), and calcaneonavicular coalition excision in 1 case (1.2%). The outcome variables will be presented at the conference. Conclusion: Anatomical lateral and medial ligament reconstruction of rotational CAI is a safe surgical treatment and leads to a favourable outcome. Beside the ligament reconstruction, associated comorbidities, as malalignment, osteochondral lesions, and others, have to be addressed at the same surgery to achieve physiological biomechanics and a complete pain relieve.
Fluid Dynamics Play a Role In Distributing Ankle Stresses in Anatomic and Injured States
Authors: Hamid Kamran S. , Scott Aaron T. , Nwachukwu Benedict U. , Parekh Selene G. , Adams Samuel B. , Danelson Kerry A. 
Published: October 2016

Category: Basic Sciences/Biologics Introduction/Purpose: In 1976, Ramsey and Hamilton published a landmark cadaveric study demonstrating a dramatic 42% decrease in tibiotalar contact area with only 1 mm of lateral talar shift. An increase in principal stress of at least 72% is predicted based on these findings though the delayed development of arthritis in minimally misaligned ankles does not appear to be commensurate with the results found in dry cadaveric models. We hypothesize that synovial fluid is a previously unrecognized factor that contributes significantly to stress distribution in the tibiotalar joint in anatomic and injured states. Methods: As it is not possible to directly measure contact stresses with and without fluid in a cadaveric model, finite element analysis (FEA) was employed for this study. FEA is a modeling technique used to calculate stresses in complex geometric structures by dividing them into small, simple components called elements. Four test groups were investigated utilizing a finite element model (FEM): baseline ankle alignment, 1 mm laterally translated talus and fibula, and the previous two bone orientations with fluid added. The FEM selected for this study was the Global Human Body Models Consortium (GHBMC) M50 version 4.2, a validated model of an average sized male. The ankle was loaded at the proximal tibia with a distributed load equal to the GHBMC body weight and first principal stress (which is also the maximum principal stress) was computed. Results: All simulations were stable and completed with no errors. In the baseline anatomic configuration, the addition of fluid between the tibia, fibula and talus reduced the maximum principal stress measured in the distal tibia at maximum load from 31.3 N/mm2 to 11.5 N/mm2. Following 1 mm lateral translation of the talus and fibula there was a modest 30% increase in the maximum stress in fluid cases. Qualitatively, translation created less high stress locations on the tibial plafond when fluid was incorporated in the model (Figure 1). Conclusion: The findings in this study demonstrate a potential role for synovial fluid in distributing stresses within the ankle that has not been considered in historical dry cadaveric studies. The increase in maximum stress predicted by simulation of an ankle with fluid is less than half that projected by cadaveric data, indicating a protective effect of fluid in the injured state. The trends demonstrated by these simulations suggest that bony alignment and fluid in the ankle joint change loading patterns on the distal tibia and should be accounted for in future experiments.
Biomechanical Consequences of First Metatarsophalangeal Joint Arthrodesis on Lesser Toes Movement
Authors: Tan Chin Yik , Fadil Muhammad Farhan Mohd 
Published: October 2016

Category: Midfoot/Forefoot Introduction/Purpose: Effect of 1st metatarsophalangeal joint (MTPJ) arthrodesis on lesser toes active range of motion (ROM) is clinically important as limitation of lesser toe active ROM may predispose to metatarsalgia and decrease push off strength during terminal stance phase of gait. This effect was however not studied in the current literature. We aim to investigate this effect and study the role of Knot of Henry as a contributing factor to this effect. Methods: 10 fresh frozen cadaveric specimens were used. Musculotendinous junction of flexor digitorum longus (FDL) was identified at medial ankle and proximal tensile force was then exerted to this part to simulate active muscle contraction. 3rd toe range of motion (ROM) and FDL excursion were measured. 1st MTPJ arthrodesis was performed by 2 crossed Kirschner wires in the standard arthrodesis angles. Measurements of 3rd toe range of motion (ROM) and FDL excursion with active muscle contraction were repeated. Knot of Henry was then identified and soft tissues connection here was then released. Same measurements were repeated. Results: There was significant decrease in the 3rd toe ROM and FDL excursion post 1st MTPJ arthrodesis, with significant improvement after knot of Henry release. Pre 1st MTPJ arthrodesis, mean 3rd toe MTPJ and PIPJ ROM, and FDL excursion were 20°, 22° and 6 mm respectively. Post 1st MTPJ arthrodesis, the respective measurements were 9.5°, 14° and 4.7 mm. Post knot of Henry release, the respective measurements were 16.5°, 19°, and 5 mm. Conclusion: Limitation of lesser toe active ROM post 1st MTPJ arthrodesis was shown in our study. In addition, our study also showed that this effect is partly contributed by knot of Henry soft tissue connection, as release of this connection improved lesser toe ROM. These results improve our understanding of 1st MTPJ arthrodesis biomechanics and also suggest potential benefits of knot of Henry release in 1st MTPJ arthrodesis to improve lesser toe active ROM and therefore decrease rate of metatarsalgia and improve push off strength during terminal stance phase of gait.
Evaluation of Brake Response Time Following Primary Bunionectomy Surgery
Authors: Raikin Steven , Lynch Mary-Katherine , Pedowitz David I. , Daniel Joseph N. , Winters Brian S. , Ahmad Jamal , Madden Anne Marie 
Published: October 2016

Category: Bunion Introduction/Purpose: Although primary bunionectomies are among the most common procedures performed by Foot and Ankle surgeons, there are currently no studies investigating postoperative driving safety in this group of patients. The purpose of this study was to evaluate postoperative brake response time (BRT) in primary right-sided bunionectomy patients as a means to determine driving preparedness. Brake response time is defined as the time, in milliseconds, between presentation of a perceived hazardous stimulus and the application of pressure to the brake pedal. We hypothesized that primary bunionectmomy patients would demonstrate BRTs comparable to control subjects at their 6-week follow-up appointment. Methods: Following IRB approval, 45 primary right-sided bunionectomy patients were prospectively identified and enrolled. All patients were managed with the same postoperative protocols. Patients were excluded if they were under the age of 18, were not in possession of a current driver’s license, had undergone a revision surgery for recurrent hallux valgus, or opted not to partake in the study. All patients were tested for their BRT utilizing a validated driving simulator at their 6-week postoperative follow-up appointment. Those patients that failed to achieve a safe brake response time less than 0.850 seconds were re-tested at weekly intervals until a safe braking time was achieved. The passing brake response time of 0.850 seconds was determined from the published control data and from testing 20 healthy volunteers in the same simulator. At each BRT test, patients were also asked to fill out an AOFAS Hallux Metatarsophalangeal-Interphalangeal Scale and a Driving Preparedness survey. Results: Each subject underwent 3 sequential drive-braking simulation tests, with their BRT being calculated as an average of the 3 times. At six weeks, the overall average BRT for all 45 patients was 0.769 seconds. 40 out of 45 patients (89%) demonstrated safe average BRT at their 6-week appointment of equal to or less than 0.850 seconds. 4 out of 45 patients (9%) were cleared to drive at their 7-week re-test, and 1 out of 45 patients (2%) was cleared to drive at an 8-week re-test. 37 of the 40 patients whose test demonstrated a safe BRT at 6 weeks responded in their survey that they “Agreed” or “Strongly Agreed” they were ready to drive at the time of testing. The average AOFAS-MT-IP score was 65.2/100. Conclusion: The present study revealed that approximately 90% of primary right-sided bunionectomy patients were able to demonstrate a BRT comparable to those of healthy control subjects at their 6-week post-op appointment. 37 of these 40 patients (93%) also reported that after completing the test, they felt ready to return to driving. Therefore, we believe that it is reasonable to offer bunionectomy patients an estimate of 6-weeks recovery time before driving.
Pes Planovarus – The Description of a New Foot Form
Authors: Frigg Arno , Aebi Janic , Maquieira Gerardo Juan J. 
Published: October 2016

Category: Hindfoot Introduction/Purpose: In classic anatomy textbooks probably based on dissections of European executed convicts it is written, that according to the direction of the subtalar joint, a deformity of the foot is generally going either into supination (cavovarus foot) or pronation (planovalgus foot). However today we live in a multiethnic society and the author has encountered feet with hindfoot varus and flat mid- and forefoot, without mueller-weiss-syndrome. This deformity should theoretically not exist and has not been described in the literature yet. Its treatment is unclear. Methods: From 8/2012 to 8/2015 984 new patients were seen in the clinic and included in the study if they showed clinically a hindfoot varus and flat mid-/forefoot on exam. 29 patients (2.9%) with 38 feet were identified (44.6+/-16.2 years, 12 male/17 female). Their main complaints and therapy were retrospectively analyzed. Two independent observers (intraobserver variability ICC 0.998) measured on a DICOM/PACS-monitor the following radiographic parameters (Fig. 1): (1) position in the Saltzman- view, (2) talus-metatarsal-1 angle dorso-plantar (dp) and lateral, (3) talus-calcaneus angle dp and lateral, (4) calcaneal pitch angle. Standard values were taken from the literature. Results: Main complaints were chronic ankle instability (n=22), pain in sports (n=18), achillestendon-tendinitis (n=14), heel pain (n=14), hallux valgus (n=10), metatarsalgia (n=8), midfoot pain (n=6), posterior tibial tendon tendinitis (n=3), midfoot osteoarthritis (n=3). There was no mueller-weiss disease. 25 feet were treated conservatively, 13 with operation. Radiological results: The hindfoot alignment view was significantly in varus 6.57+/-3.74mm (standard 1.6+/-7.2mm, P < 0.001), the talus-MT1 angel lateral was significantly flat with 5.97+/-8.3° towards a negative arch (standard 8.4+/-5.85° positive arch, P < 0.001), the talus- MT1- angle dp was 2.4+/-8.2° in abduction (standard 7.7+/-8.2°, P=0.2), the calcaneus pitch angle was 18.63+/-6.45° (standard 24.5+/- 3.0, P < 0.001), the talus-calcaneus angle lateral was 48.13+/-6.76° (standard 43.4+/-7.1°, P < 0.001), the talus calcaneus angle dp was 25.35+/-8.22° (standard 24.1+/-5.7+, P=0.38). Conclusion: We found in 2.9% of our patients this new foot form, which is significantly different from standard feet characterized by a simultaneous hindfoot varus and flatfoot with negative arch. This seems paradox, as this is not in line with the axis of the subtalar joint. These feet pose a difficulty in treatment as for example a correction of the hindfoot varus in chronic ankle instability would increase the flatfoot and the correction of flatfoot in midfoot pain/metatarsalgia/heel pain would increase the hindfoot varus. Therefore conservative treatment was the primary choice because surgery would include a simultaneous correction of both deformities. Further research is necessary.