bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial–degree of freedom improvement of interference alignment in multi-input, multi-output interference channels
Authors: Li Yi-bing , Diao Xue-ying , Dong Qian-hui
Published: January 2017

As we know, the degree of freedom approximates the capacity of a network. To improve the achievable degree of freedom in the K-user interference network, we propose a rank minimization interference minimization algorithm. Unlike the existing methods concentrating on the promotion of degree of freedom, our rank optimization method works directly with the interference matrix rather than its projection using the receive beamformers. Moreover, we put the trace constraint of the square root of desired matrix into the rank optimization to prevent the received signal-to-interference-plus-noise ratio from reduction. The decoders are designed through a weight interference leakage minimization method. Considering that the practical obtainable signal-to-noise ratio may be limited, we improve the design of decoders in rank minimization interference minimization, and propose the rank minimization rate maximization. Rank minimization rate maximization aims to reduce the impact of interference on undesired users as much as possible while improving the desired data rate. Simulation results show that rank minimization interference minimization algorithm can provide more interference-free dimensions for desired signals than other rank minimization methods. Rank minimization rate maximization outperforms rank minimization interference minimization at low-to-moderate signal-to-noise ratios, and its performance gets closer to rank minimization interference minimization with the increase in signal-to-noise ratio. Furthermore, in an improper system, rank minimization rate maximization still performs well.
Situation awareness via Internet of things and in-network data processing
Authors: Ehala Johannes , Kaugerand Jaanus , Pahtma Raido , Astapov Sergei , Riid Andri , Tomson Timo , Preden Jürgo-Sören , Mõtus Leo
Published: January 2017

Computing on the edge of the Internet of things comprises among other tasks in-sensor signal processing and performing distributed data fusion and aggregation at network nodes. This poses a challenge to distributed sensor networks of low computing power devices that have to do complex fusion, aggregation and signal processing in situ. One of the difficulties lies in ensuring validity of data collected from heterogeneous sources. Ensuring data validity, for example, the temporal and spatial correctness of data, is crucial for correct in-network data fusion and aggregation. The article considers wireless sensor technology in military domain with the aim of improving situation awareness for military operations. Requirements for contemporary intelligence, surveillance and reconnaissance applications are explored and an experimental wireless sensor network, designed to enhance situation awareness to both in-the-field units and remote intelligence operatives, is described. The sensor nodes have the capability to perform in-sensor signal processing and distributed in-network data aggregation and fusion complying with edge computing paradigm. In-network data processing is supported by service-oriented middleware which facilitates run-time sensor discovery and tasking and ad hoc (re)configuration of the network links. The article describes two experiments demonstrating the ability of the wireless sensor network to meet intelligence, surveillance and reconnaissance requirements. The efficiency of distributed data fusion is evaluated and the importance and effect of establishing data validity is shown.
Deep combining of local phase quantization and histogram of oriented gradients for indoor positioning based on smartphone camera
Authors: Jiao Jichao , Deng Zhongliang
Published: January 2017

To achieve high accuracy in indoor positioning using a smartphone, there are two limitations: (1) limited computational and memory resources of the smartphone and (2) the human walking in large buildings. To address these issues, we propose a new feature descriptor by deeply combining histogram of oriented gradients and local phase quantization. This feature is a local phase quantization of a salient histogram of oriented gradient visualizing image, which is robust in indoor scenarios. Moreover, we introduce a base station–based indoor positioning system for assisting to reduce the image matching at runtime. The experimental results show that accurate and efficient indoor location positioning is achieved.
A mechanism of topology optimization for underwater acoustic sensor networks based on autonomous underwater vehicles
Authors: He Ming , Liu Fangxin , Miao Zhuang , Zhou Huan , Chen Qiuli
Published: January 2017

Limited energy, high mobility, and unsteady acoustic communication links render the underwater acoustic sensor networks subject to performance reduction. To solve this problem, a topology optimization method, also called TO-A algorithm, is developed based on topology reconfiguration. First, the proposed method optimizes the coverage rate of underwater acoustic sensor networks by adjusting the location of sensor nodes through simulating fish behaviors. Second, to optimize the connectivity of underwater acoustic sensor networks, the proposed method, using edge nodes, repairs disconnected positions and eliminates key nodes in underwater acoustic sensor networks. Third, a topology optimization strategy, also called TO-DA algorithm, is developed for Double-autonomous underwater vehicles to improve the robustness and adaptability of the network topology. When the inherent law of underwater acoustic sensor networks topology formation is further found, the method for optimizing network topology is proposed, which based on the triangle principle eliminates those key nodes and can help with the survivability of network regeneration. The method proves reasonable and valid by stimulation and contrast examinations. The comparison of TO-A algorithm and TO-DA algorithm shows that under low energy consumption, TO-A algorithm can keep the network coverage at about 97% for a long time, connectivity rate above 89%, while the TO-DA algorithm can improve the survivability of the network by above 50% at the expense of 8.5% of the network coverage.
An adaptive network allocation vector timer-based carrier sense multiple access with collision avoidance medium access control protocol for underwater acoustic sensor networks
Authors: Rahman Md Arifur , Lee Youngdoo , Koo Insoo
Published: January 2017

Underwater sensor networks with acoustic communications are significantly challenged due to several unique characteristics, such as energy consumption, high propagation delay, and severely limited distance-dependent bandwidth. These unique characteristics make it difficult to directly adopt schemes for underwater acoustic sensor networks that are already proven for reliable terrestrial wireless sensor networks. In particular, propagation delay is one of the key elements for delay-sensitive underwater applications. In this article, we propose an adaptive network allocation vector timer–based underwater carrier sense multiple access with collision avoidance medium access control protocol with propagation delay estimation to maximize network throughput while reducing the end-to-end delay in transmission for delay-sensitive applications. In the proposed scheme, we first calculate the distance between the sensor nodes using received signal strength and the Lambert W function and then estimate the propagation delay. Consequently, the neighbor node can set an adaptive network allocation vector timer based on the estimated propagation delay. Our extensive simulation results reveal that the proposed scheme outperforms the distance-aware collision avoidance protocol, the propagation-delay-tolerant collision avoidance protocol, and the maximum propagation delay-based medium access control protocol in terms of network throughput and end-to-end delay. The simulation results also show that the proposed scheme has near-optimal performance compared to the knowledge-based medium access control scheme, which utilizes the location information of each sensor node.
A differential game model of intrusion detection system in cloud computing
Authors: Li Zhi , Xu Haitao , Liu Yanzhu
Published: January 2017

The multi-mesh distributed and open structure of cloud computing is more weak and vulnerable to security threats. Intrusion detection system should be incorporated in cloud infrastructure to monitor cloud resources against security attacks. In this article, the interaction between rational cloud resource defender and the potential malicious user in the cloud as a differential game is investigated. The feedback Nash equilibrium of the game is reviewed and a complex decision-making process and interactions between the cloud resource defender and a malicious user of cloud are also analyzed. The system results support a theoretical foundation in detecting the malicious attack, which can help cloud intrusion detection system make the optimal dynamic strategies to improve the defensive ability.
Depression and Suicidality in Gay Men: Implications for Health Care Providers
Authors: Lee Carrie , Oliffe John L. , Kelly Mary T. , Ferlatte Olivier
Published: January 2017

Gay men are a subgroup vulnerable to depression and suicidality. The prevalence of depression among gay men is three times higher than the general adult population. Because depression is a known risk factor for suicide, gay men are also at high risk for suicidality. Despite the high prevalence of depression and suicidality, health researchers and health care providers have tended to focus on sexual health issues, most often human immunodeficiency virus in gay men. Related to this, gay men’s health has often been defined by sexual practices, and poorly understood are the intersections of gay men’s physical and mental health with social determinants of health including ethnicity, locale, education level, and socioeconomic status. In the current article summated is literature addressing risk factors for depression and suicidality among gay men including family acceptance of their sexual identities, social cohesion and belonging, internalized stigma, and victimization. Barriers to gay men’s help seeking are also discussed in detailing how health care providers might advance the well-being of this underserved subgroup by effectively addressing depression and suicidality.
The Influence of Older Adults’ Beliefs and Attitudes on Adopting Fall Prevention Behaviors
Authors: Stevens Judy A. , Sleet David A. , Rubenstein Laurence Z.
Published: January 2017

Among Americans aged 65 years and older, falls are the leading cause of injury death and disability, and finding effective methods to prevent older adult falls has become a public health priority. While research has identified effective interventions delivered in community and clinical settings, persuading older adults to adopt these interventions has been challenging. Older adults often do not acknowledge or recognize their fall risk. Many see falls as an inevitable consequence of aging. Health care providers can play an important role by identifying older adults who are likely to fall and providing clinical interventions to help reduce fall risks. Many older people respect the information and advice they receive from their providers. Health care practitioners can encourage patients to adopt effective fall prevention strategies by helping them understand and acknowledge their fall risk while emphasizing the positive benefits of fall prevention such as remaining independent. To help clinicians integrate fall prevention into their practice, the Centers for Disease Control and Prevention launched the STEADI (Stopping Elderly Accidents, Deaths, and Injuries) initiative. It provides health care providers in primary care settings with resources to help them screen older adult patients, assess their fall risk, and provide effective interventions.
Changes in contrast transit times on digital subtraction angiography post-Pipeline Embolization Device deployment
Authors: Hussein Ahmed E , Linninger Andreas , Shakur Sophia F , Charbel Fady T , Hsu Chih-Yang , Charbel Fady T , Alaraj Ali
Published: January 2017

It is postulated that hemodynamic changes occur in the distal vascular bed post-deployment of Pipeline Embolization Devices (PEDs). In this paper, we evaluate changes in the contrast transit times (TTs) on digital subtraction angiography (DSA) post-PED interventions. DSA films were analyzed using custom-made software for the time-density relationship at baseline and compared to post-PED deployment. All analyses were performed within the middle cerebral artery (MCA) M1 segment. Analyses included TT10%–100% (time needed for the contrast to change from 10% image intensity to 100%), TT100%–10%, and TT25%–25%. Forty-four patients were included. We found a significant decrease in TT10%–100% (2.79 to 2.24 seconds, p < 0.001) post-PED. There was a significant correlation between the percentage change in TT100%–10% and aneurysm size ( p = 0.02). There was also a significant decrease in TT25%–25% (7.07 to 6.41 seconds, p = 0.02) post-PED. Moreover, there was a significant correlation between the absolute or percentage changes in TT25%–25% and aneurysm size (rho = 0.54, p = 0.05 and rho = 0.29, p = 0.05, respectively). Statistically significant distal intracranial hemodynamic changes occur post-PED deployment. These hemodynamic changes appear to be more pronounced with large and giant aneurysms.
Dynamic Hip Screw Fixation versus Multiple Screw Fixation for Intracapsular Hip Fracture
Authors: Jettoo Prithee , James Philip
Published: January 2017

Purpose

To compare dynamic hip screw (DHS) fixation with multiple screw fixation for intracapsular hip fractures in terms of complications and conversion to hemiarthroplasty or total hip arthroplasty (THA).

Methods

Records of 52 884 patients aged ≥50 years who underwent internal fixation using a dynamic hip screw (n=18 014, 34.1%) or multiple screws (n=34 870, 65.9%) for intracapsular femoral neck fracture from September 2007 to September 2013 were extracted from the hospital admission database that covers all admissions to the National Health Service hospitals in England using the ICD-10 and OPCS-4 codes. Gender, age, and Charlson comorbidity score of each patient were recorded, as were complications at specific time intervals and revision to hemiarthroplasty or THA at one and 4 years.

Results

Compared with DHS fixation, multiple screw fixation resulted in shorter hospital stay (15 vs. 13 days, p<0.001) and lower rates of 30-day myocardial infarction (2% vs. 1.5%, p=0.022), 30-day lower respiratory tract infection (12.4% vs. 10.6%, p=0.001), 90-day mortality (10.4% vs. 8.6%, p=0.001), and avascular necrosis (0.1% vs. 0.06%, p=0.032), but a higher rate of conversion to hemiarthroplasty or THA at one or 4 years (all p<0.001).

Conclusion

Multiple screw fixation for intracapsular hip fracture was associated with a higher conversion rate to hemiarthroplasty or THA at one and 4 years, compared with DHS fixation.
Predictors of Mortality in Patients with Femoral Neck Fracture
Authors: Major Lisa J , North John B
Published: January 2017

Purpose

To identify patient and procedural factors associated with in-hospital mortality following a femoral neck fracture.

Methods

Records of 598 female and 259 male consecutive patients aged 29 to 108 (median, 82) years admitted between 2010 and 2014 with femoral neck fracture were retrospectively reviewed to determine patient and procedural factors associated with in-hospital mortality.

Results

73% of patients were operated on within 48 hours of admission. The in-hospital mortality was 7.5%, with 2.1% occurring preoperatively and 5.4% postoperatively. Factors associated with increased preoperative mortality included being non-ambulant prior to admission (p=0.015), residence in interim care (p=0.001) or low-level care (p=0.049), having synchronous fractures (p=0.001), and having a concurrent acute medical condition (p<0.001). Patient factors associated with increased in-hospital mortality included male gender (p=0.041), age >80 years (p=0.001), non-ambulatory status (p=0.015), residence in high-level care (p=0.031) or low-level care (p=0.018), American Society of Anesthesiologists grade 4 or 5 (p<0.001), weekend admission (p<0.001), and having an acute medical condition on admission (p<0.001). Procedural factors associated with increased in-hospital mortality included >96-hour delay to surgery from admission (p<0.001), surgery over the weekend (p=0.005), and surgical interventions other than total hip arthroplasty (p<0.05).

Conclusion

Identification of patient and procedural factors can guide changes in best practice to decrease mortality following a femoral neck fracture.
Conservative versus Surgical Treatment for Displaced Fracture of the Medial Process of the Calcaneal Tuberosity
Authors: Li Bing , Wu Gen-Bin , Yang Yun-Feng
Published: January 2017

Purpose

To compare the outcome following conservative or surgical treatment for displaced fracture of the medial process of the calcaneal tuberosity.

Methods

14 men and 4 women aged 20 to 44 years chose to undergo conservative (9 feet) or surgical (10 feet) treatment by a single surgeon for closed displaced fracture of the medial process of the calcaneal tuberosity. The injury mechanism was a fall from a height of <1.5 m; the mean time from injury to treatment was 3 (range, 1–7) days. Conservative treatment comprised immobilisation in a plaster cast. Surgical treatment involved fixation with a half-thread cannulated screw for large fragments (in 6 feet) or a mini-plate for comminuted fragments (in 4 feet). At the final follow-up, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score was evaluated.

Results

The conservative and surgery groups were comparable in terms of age, gender, and fracture displacement. The mean follow-up duration was 20 (range, 14–24) months. All patients had bone union; none had implant loosening or breakage. One patient with surgical treatment developed skin numbness at the medial aspect of the heel that resolved following neurotrophic drug treatment for 3 months. The surgery group achieved earlier full weight-bearing (5.8 vs. 7.5 weeks, p<0.001) and return to work (5.9 vs. 8.2 weeks, p=0.048), but comparable AOFAS score (89.0 vs. 88.2, p=0.4).

Conclusion

Surgery for displaced fracture of the medial process of the calcaneal tuberosity enabled earlier full weight-bearing and return to work but comparable AOFAS score.
Patient-Specific Instrumentation versus Conventional Instrumentation in Total Knee Arthroplasty
Authors: Chan Warwick Chun-Wang , Pinder Elizabeth , Loeffler Mark
Published: January 2017

Purpose

To compare patient-specific instrumentation (PSI) with conventional instrumentation in total knee arthroplasty (TKA) in terms of component alignment, operating time, and the learning curve required in a non-teaching hospital.

Methods

Records of 33 men and 29 women aged 50 to 88 (mean, 71) years who underwent TKA for osteoarthritis using PSI (n=31) or conventional instrumentation (n=31) by a single surgeon were reviewed. The choice of instrumentation was made by the patient; the surgeon did not express any preference and had not used PSI before. All patients used the same cemented, cruciate-retaining system.

Results

The PSI and conventional instrumentation groups were comparable in terms of age, body mass index (BMI), American Society of Anesthesiologists grade, pre- and post-operative haemoglobin level, and the need for blood transfusion. Compared with conventional instrumentation, PSI resulted in a smaller coronal femoral component angle (7.7° vs. 6.4°, p=0.003) and posterior tibial slope angle (6.4° vs. 3.2°, p=0.0001), and smaller variance of the respective angles (p=0.006 and p=0.003). In patients with a BMI ≥30, PSI still resulted in a smaller posterior tibial slope angle (5.8° vs. 3.1°, p=0.015) and variance of the angle (p=0.02). The mean tourniquet time was shorter in the PSI group in all patients (p=0.013) and in patients with BMI ≥30 kg/m2 (p=0.0008), and its variance was also smaller in the PSI group (p=0.0004). There was no learning curve required.

Conclusion

PSI was simple to use, with no learning curve required. It can be used in non-teaching hospitals and in patients with a high BMI and in cases where the use of an intramedullary alignment guide would be problematic due to previous femoral trauma.
Length, Thickness, and Elasticity of the Patellar Tendon after Closed Wedge High Tibial Osteotomy: A Shear Wave Elastographic Study
Authors: Botanlioglu Huseyin , Kaynak Gokhan , Kantarci Fatih , Guven Mehmet Fatih , Zengin Gokhan , Aydingoz Onder
Published: January 2017

Purpose

To compare the length, thickness, and elasticity of the patellar tendon between operated and non-operated knees following closed wedge high tibial osteotomy (CWHTO).

Methods

Three men and 17 women aged 52 to 75 (mean, 64.8) years who underwent unilateral CWHTO by a single surgeon and were followed up for a mean of 11 (range, 5–22) years were included, as were 3 male and 17 female healthy controls aged 35 to 61 (mean, 47.9) years. The length, thickness, and elasticity of the bilateral patellar tendons in the patients and healthy controls were measured using shear wave elastography.

Results

In the CWHTO patients, the patellar tendon on the operated side was thicker (4.4 vs. 3.3 mm, p=0.001) and stiffer (74.1 vs. 47.7 kPa, p<0.001) than on the non-operated side.

Conclusion

Patellar tendon contracture (thickening and stiffening) is associated with CWHTO.
Correlation between the Distal Anterior Femoral Cortical Axis and Femoral Rotational Alignment: An Anatomic Study
Authors: Sathappan Sathappan S , Tan Marcus Wei Ping , Ginat Daniel , Walsh Michael G , Schweitzer Mark E , Di Cesare Paul E
Published: January 2017

Purpose

To determine the correlation between the distal anterior femoral cortical axis (DAFCA) and the femoral rotational alignment/axis.

Methods

Magnetic resonance images (MRI) of 82 knees in 34 men and 23 women aged 16 to 47 (mean, 33.4) years were reviewed by a musculoskeletal radiologist. Their diagnoses included meniscal tear (n=4), chondromalacia (n=25), anterior cruciate ligament tears (n=11), and normal (n=42). In all patients the collateral ligaments were intact. The transepicondylar axis (TEA), posterior condylar axis (PCA), Whiteside line (WL), and joint line were drawn on the images, and the condylar twist angle (CTA), TEA-WL angle, DAFCA, epicondylar cortical angle (ECA), and condylar cortical angle (CCA) were measured. The correlations among ECA, CCA, and CTA (control) were assessed.

Results

The mean distances between the joint line and the TEA, PCA, and DAFCA were 30.8, 22.1, and 62.2 mm, respectively. The angles subtended by the intersection between the standard axes (TEA, PCA, and WL) and the DAFCA were determined. There was correlation between the CTA and ECA (r=0.34, p<0.05), between the ECA and the CCA (r=0.80, p<0.0001), and between the CTA and the CCA (r=–0.19, p=0.08).

Conclusion

There was correlation between the DAFCA and TEA and PCA; DAFCA can be used to determine the femoral rotational alignment when the standard landmarks are distorted by severe soft tissue and bone loss.
Intra-Operative Blood Salvage in Total Hip and Knee Arthroplasty
Authors: Dan Michael , Liu David , Martos Sara Martinez , Beller Elaine
Published: January 2017

Purpose

To review records of 371 patients who underwent total hip or knee arthroplasty (THA or TKA) with intra-operative blood salvage to determine the allogeneic blood transfusion rate and the predictors for allogeneic blood transfusion.

Methods

Records of 155 male and 216 female consecutive patients aged 17 to 95 (mean, 70) years who underwent primary THA or TKA by a single surgeon with the use of intra-operative blood salvage were reviewed.

Results

The preoperative haemoglobin level was <120 g/dl in 15% of THA patients and 5% of TKA patients; the allogeneic transfusion rate was 24% in THA patients and 12% in TKA patients. Despite routine use of intra-operative blood salvage, only 59% of THA patients and 63% of TKA patients actually received salvaged blood, as a minimum of 200 ml blood loss was required to activate blood salvage. In multivariable analysis, predictors for allogeneic blood transfusion were female gender (adjusted odds ratio [OR]=2.8, p=0.02), age >75 years (adjusted OR=5.9, p<0.001), and preoperative haemoglobin level <120 g/l (adjusted OR=30.1, p<0.001), despite the use of intra-operative blood salvage. Patients who received allogeneic blood transfusion had a longer hospital stay and greater complication rate.

Conclusion

Intra-operative blood salvage is not effective in preventing allogeneic blood transfusion in patients with a preoperative haemoglobin level <120 g/l. It should be combined with preoperative optimisation of the haemoglobin level or use of tranexamic acid.
Bioceramic Bone Graft Substitute for Treatment of Unicameral Bone Cysts
Authors: Fillingham Yale A , Cvetanovich Gregory L , Haughom Bryan D , Erickson Brandon J , Gitelis Steven
Published: January 2017

Purpose

To review the outcome of 12 patients who underwent debridement and injection of bioceramic for unicameral bone cyst (UBC). The resorption rate of the bioceramic was estimated by both traditional and novel methods.

Methods

Records of 10 males and 2 females aged 6 to 34 years who underwent debridement and injection of bioceramic for UBC and were followed up for a mean of 41 (range, 26–57) months were reviewed. Functional outcome was assessed using the self-completed Musculoskeletal Tumor Society (MSTS) questionnaire. Radiological outcome was assessed using both original and modified Neer Outcome Rating System. The resorption rate of the bioceramic was estimated using both traditional and novel (ImageJ) methods.

Results

The mean MSTS score was 29.7 (range, 28–30) indicating excellent functional outcome. Of the 12 patients, 9 achieved complete healing and 3 had a residual cyst of 1%, 11%, and 52%. The last was considered a local recurrence, and the patient underwent repeat percutaneous injection of the bioceramic 1.5 years later and remained disease-free 4 years later. The mean resorption rate was 29% faster when estimated using the traditional rather than the ImageJ method (0.47 vs. 0.33 cm3/day, p=0.02). In the patient with recurrence, the resorption rate was faster than the average (0.68 vs. 0.33 cm3/day).

Conclusion

A single percutaneous injection of the bioceramic for UBC achieved good functional and radiological outcome while avoiding donor-site morbidity.
Compression and Flexural Strength of Bone Cement Mixed with Blood
Authors: Tan JH , Koh Bryan TH , Ramruttun AK , Wang Wilson
Published: January 2017

Purpose

To assess the compression and flexural strength of bone cement mixed with 0 ml, 1 ml, or 2 ml of blood.

Methods

High viscosity polymethyl methacrylate (PMMA) loaded with or without gentamicin was used. Blood was collected from total knee arthroplasty patients. In the same operating room, one pack of cement each was mixed with 0 ml (control), 1 ml, or 2 ml of blood for 1 minute during the dough phase. The dough was extruded into cylindrical and rectangular moulds for 20 minutes of setting, and then cured in phosphate buffered saline at 37±1°C for 7 days. The samples were visually inspected for fractures and areas of weakness, and then scanned using micro-computed tomography. 48 gentamicin-loaded and 59 non-gentamicin-loaded samples mixed with 0 ml (control), 1 ml, or 2 ml of blood were randomised for flexural and compression strength testing; each group had at least 6 samples.

Results

In samples loaded with or without gentamicin, the flexural and compressive strength was highest in controls, followed by samples mixed with 1 ml or 2 ml of blood. In samples mixed with 2 ml of blood, the flexural strength fell below the standard of 50 MPa. In samples mixed with 2 ml of blood and all gentamicin-loaded samples, the compressive strength fell below the standard of 70 MPa. Micro-computed tomography revealed areas of voids and pores indicating the presence of laminations and partitions within.

Conclusion

The biomechanical strength of PMMA contaminated with blood may decrease. Precautions such as saline lavage, pack drying the bone, change of gloves, and prompt insertion of the implant should be taken to prevent blood from contaminating bone cement.
Effect of Povidone Iodine and Hydrogen Peroxide on Fracture Healing: A Histomorphometric Study on Rats
Authors: Husodo Kurniadi , Kamal Achmad Fauzi , Yusuf Achmad Aulia
Published: January 2017

Purpose

To evaluate the effect of povidone iodine and hydrogen peroxide on fracture healing in a rat model.

Methods

The middle section of the right femur of 36 male Sprague Dawley rats was osteotomised with a saw. In the control group (n=9), the wound was irrigated with 100 ml 0.9% saline. In the 10% povidone iodine (n=9), 1% povidone iodine (n=9), and 3% hydrogen peroxide (n=9) groups, the wound was completely soaked with the respective solution for 2 minutes, and then irrigated with 100 ml saline. The osteotomy was fixed with an intramedullary Kirschner wire. Rats were euthanised at week 1, 2, and 5. In each femur, the percentage area of osseous, cartilaginous, and fibrous tissue in the callus was evaluated in 3 slides (one median and 2 paramedian).

Results

The control group differed significantly to the other 3 groups (p=0.023 to p<0.001) in weeks 1, 2, and 5, except for the 1% povidone iodine group in terms of percentage of osseous (p=0.349) and fibrous (p=0.999) tissue. The healing process was similar in the 1% povidone iodine group and the control group, whereas healing was impaired in the 10% povidone iodine group and 3% hydrogen peroxide group, as indicated by the lower percentage of osseous tissue, higher percentage of fibrous tissue, and increased percentage of cartilaginous tissue between weeks 2 and 5 (delayed bone healing).

Conclusion

The 1% povidone iodine solution is recommended as the irrigation adjuvant in fracture surgery.
Tibial Tubercle to Trochlear Groove Distance and Index in Children with One-Time versus Recurrent Patellar Dislocation: A Magnetic Resonance Imaging Study
Authors: Yeoh Ching Sing Nicholas , Lam Kai Yet
Published: January 2017

Purpose

To compare the tibial tubercle to trochlear groove (TT-TG) distance and index using magnetic resonance imaging (MRI) between children with one-time and recurrent patellar dislocation.

Methods

Records of first-time acute patellar dislocations from 2007 to 2012 were reviewed. 20 males and 23 females aged 10 to 17 years at presentation were included for measurements of the bony and cartilaginous-tendon TT-TG distance and index. Recurrent patellar dislocation was defined as having more than one episode of dislocation within 2 years of the index injury.

Results

The recurrent dislocation rate was 30.2% (13 out of 43). Patients with recurrent patellar dislocation had a higher mean bony TT-TG distance (17.4 vs. 14.2 mm, p=0.026), cartilaginous-tendon TT-TG distance (18.8 vs. 15.3 mm, p=0.029), and TT-TG index (0.41 vs. 0.33, p=0.008), compared with one-timers. Males had a larger patellofemoral joint than females (49.0 vs. 44.8 mm, p=0.01). The risk of recurrent patellar dislocation was higher in patients with a bony TT-TG distance >14 mm (relative risk [RR]=6.4), a cartilaginous-tendon TT-TG distance >13.5 mm (RR=8.8), and a TT-TG index >0.26 (RR=6.7).

Conclusion

Children with recurrent patellar dislocation have higher TT-TG distance and index when compared with one-timers.
Atypical Periprosthetic Femoral Fracture: A Case Report
Authors: Woo Siu-Bon , Choi Siu-Tong , Chan Wai-Lam
Published: January 2017

We report an 82-year-old woman who underwent fixation with a long-spanning cable-plate for a bisphosphonate-induced Vancouver B1 periprosthetic femoral fracture. Non-union and breakage of the plate occurred at 16 months and necessitated revision surgery using a long-stem femoral prosthesis augmented with a cable-plate construct. Bone union was achieved eventually after 10 months.
Correlation of Femoral Tunnel Length with Body Height, Limb Length, and Thigh Length in Indian Patients Undergoing Anterior Cruciate Ligament Reconstruction
Authors: Gupta Ravi , Malhotra Anubhav , Kumar Pawan , Masih Gladson David
Published: January 2017

Purpose

To measure the femoral tunnel length created through a far medial portal and determine its correlation with body height, limb length, and thigh length in 404 Indian patients undergoing anterior cruciate ligament (ACL) reconstruction.

Methods

364 male and 40 female Indian patients aged 18 to 51 (mean, 26.8) years underwent ACL reconstruction by a single surgeon using the hamstrings tendon autograft. Their body height, limb length, and thigh length were measured by a single assessor, as was the femoral tunnel length.

Results

The mean femoral tunnel length was 34.5 mm. It was <30 mm in 28 patients and <25 mm in 2 patients. The correlation coefficients of the femoral tunnel length with body height, limb length, and thigh length were 0.485 (p<0.0001), 0.426 (p<0.0001), and 0.304 (p<0.0001). No patient had posterior wall blowout fracture.

Conclusion

The femoral tunnel length positively correlated with body height, limb length, and thigh length in 404 Indian patients.
Improvement in Health-Related Quality of Life after Unilateral Total Knee Arthroplasty in Patients with Bilateral Knee Osteoarthritis
Authors: Tan Desmond Wei , Teh Daniel Jing Wen , Razak Hamid Rahmatullah Bin Abd , Tan Andrew Hwee Chye
Published: January 2017

Purpose

To review the outcome of unilateral total knee arthroplasty (TKA) in patients with bilateral knee osteoarthritis (OA) to determine whether unilateral TKA can achieve good health-related quality of life (HRQoL).

Methods

Records of 68 women and 25 men with severe bilateral knee OA who underwent unilateral TKA on the more symptomatic knee by a single surgeon and did not return for the second TKA within 2 years were reviewed. Outcome at 6 months and 2 years was assessed using the mental and physical component summary (MCS and PCS) of the Short-Form 36 (SF-36) for HRQoL as well as the Oxford Knee Score (OKS) and Knee Society Score (KSS) for knee-specific outcome.

Results

The SF-36, OKS, and KSS improved significantly after unilateral TKA. Respectively for MCS and PCS of SF-36, OKS, and KSS knee and function scores, 65%, 89%, 98%, 98%, and 98% of patients reported absolute improvement at 2 years. Respectively for PCS, OKS, and KSS function score that a minimal clinically important difference (MCID) was established, 77%, 96%, and 80% of patients achieved MCID at 2 years.

Conclusion

Unilateral TKA achieves good outcome in HRQoL at 2 years in patients with bilateral knee OA.
Arthroscopic Transphyseal Anterior Cruciate Ligament Reconstruction in Adolescent Athletes
Authors: Dei Giudici Luca , Fabbrini Roberto , Garro Luca , Arima Serena , Gigante Antonio , Tucciarone Agostino
Published: January 2017

Purpose

To evaluate the 5-year outcome of arthroscopic transphyseal anterior cruciate ligament (ACL) reconstruction in 19 adolescent athletes.

Methods

14 male and 5 female adolescent athletes aged 12 to 16 (mean, 13.9) years with Tanner stage 2 or 3 open physes underwent arthroscopic transphyseal ACL reconstruction by a single surgeon and were followed up for 5 years. Patients were evaluated using the numerical rating score (NRS) for pain, knee osteoarthritis outcome score (KOOS), International Knee Documentation Committee (IKDC) score, Tegner Activity Scale, and Lysholm Score, as well as the leg length discrepancy, femorotibial alignment, varus or valgus deformities, active and passive knee range of motion.

Results

At 5-year follow-up, physes were closed in all patients. The mean NRS for pain improved from 7.2 to 1.6; the KOOS improved from 55.3 to 88; the mean IKDC score improved from 34.5 to 84; the mean Tegner Activity Scale improved from 2.7 to 8.2 and was comparable with that before injury (8.4); and the mean Lysholm score improved from 36.3 to 84.6. All except 2 patients returned to their pre-injury level of sports activity after a mean of 25 weeks. The 2 exceptions had a 2+ Jerk test and a 3+ Lachman test; one of them also had positive signs for a lateral meniscal lesion. Both had sustained a second trauma not long before the 5-year follow-up. Two patients had reduced sensitivity in the anteromedial aspect of the proximal third of the tibia. One patient had leg length discrepancy of +1.5 cm owing to overgrowth response of the physis.

Conclusion

Transphyseal ACL reconstruction is a viable option for skeletally immature patients, with high reproducibility, a high rate of return to sport, and a low incidence of growth disturbance. Early surgery can prevent the onset of meniscal lesions and early osteoarthritis.
Distal Femoral Cortical Hypertrophy after Hip Arthroplasty Using a Cementless Double-Tapered Femoral Stem
Authors: Cho Yoon Je , Chun Young Soo , Rhyu Kee Hyung , Baek Jong Hun , Liang Hu
Published: January 2017

Purpose

To review 437 hips in 404 patients who underwent total hip arthroplasty (THA) or hemiarthroplasty using the Accolade TMZF stem to determine the incidence and risk factors of distal femoral cortical hypertrophy (DFCH).

Methods

Records of 437 hips in 169 men and 235 women aged 26 to 100 (mean, 65.7) years who underwent THA (n=293) or hemiarthroplasty (n=144) using the Accolade TMZF femoral stem by 2 senior surgeons and were followed up for a mean of 54.7 months were reviewed. Clinical outcome was assessed using the modified Harris Hip Score and visual analogue score for pain. Proximal femoral geometry and canal flare index were assessed on preoperative radiographs, and DFCH, stem position, subsidence, loosening, and stress shielding were assessed on postoperative radiographs according to the Gruen zone.

Results

Of 437 hips, 27 (6.2%) developed DFCH and 410 did not. Hips with DFCH had a higher incidence of thigh pain (18.5% vs. 2.2%, p<0.001) and earlier onset of thigh pain (12.3 vs. 20.8 months, p=0.015), compared with those without. Nonetheless, all femoral stems were well-fixed, and no osteolysis or loosening was detected. The 2 groups achieved comparable clinical outcome in terms of Harris Hip Score and pain. The mean canal flare index was higher in hips with than without DFCH (3.706 vs. 3.294, p=0.002). The mean vertical subsidence of the femoral stem was lower in hips with than without DFCH (1.5 vs. 3.4 mm p<0.001). Subsidence negatively correlated with the canal flare index (correlation coefficient= −0.110, p=0.022). The incidence of the DFCH increased with each unit of increment in canal flare index (odds ratio [OR]=1.828, p=0.043) and each year younger in age (OR=0.968, p=0.015).

Conclusion

The incidence of DFCH in hips with the Accolade TMZF stem was 6.2%. Patients with a higher canal flare index and younger age had a higher incidence of DFCH. Nonetheless, DFCH did not affect clinical outcome or femoral stem stability.
Mid-Term Outcome of Total Hip Arthroplasty Using a Short Stem
Authors: Malhotra Rajesh , Kumar Vijay
Published: January 2017

Purpose

To review the outcome of total hip arthroplasty (THA) using a short femoral stem in 33 hips.

Methods

Records of 33 hips in 20 men and 10 women aged 25 to 40 (mean, 30) years who underwent cementless THA using a short femoral stem by a single senior surgeon were reviewed. The diagnosis included avascular necrosis (n=9), ankylosing spondylitis (n=12), rheumatoid arthritis (n=7), post-traumatic arthritis (n=4), and Hurler syndrome (n=1). Clinical outcome was assessed using the Harris Hip Score. Radiological outcome was assessed according to a modified Gruen zoning system. Stem positioning (neutral, varus, valgus) and bone contact were evaluated, as were fixation and early host response as well as subsidence and changes in the calcar region (zone 5). Trabecular response (trabecular attachment), spot welds, cortical hypertrophy, and pedestal formation were determined. Heterotopic ossification was graded by the Brooker classification.

Results

The mean follow-up period was 6.5 years. The mean Harris Hip Score improved from 40 to 90. All hips achieved immediate postoperative stability. No patient had thigh pain. Four hips had varus placement (5°–7°) of the stem; all were asymptomatic and remained stable without any migration. Evidence of proximal load transfer (endosteal spot welds) between the endosteum and the stem in zones 2 and/or 4 was noted in 12 hips on both sides and in 8 hips on the lateral side only. At one year, all stems showed evidence of osseointegration. None had subsidence or progressive varus migration. There was no radiolucent line or osteolysis around the stem, pedestal formation or buttressing at the prosthesis tip, or cortical hypertrophy. One patient had grade I heterotopic ossification that was not clinically significant. One patient had a 1.5 cm leg lengthening. One patient had a discharging sinus, a loosened acetabular component, and intrapelvic migration at 2 years and underwent implant removal and debridement. One patient developed a crack in the proximal femur even with the smallest stem. The stem was fixed with cerclage wiring and remained stable with no migration.

Conclusion

A short femoral stem design that transfers load proximally through a prominent lateral flare achieved good short-term outcome in younger patients. Nonetheless, the ease of removal and preservation of bone at the time of revision should guide the choice of the design of the short stem.
Frequent Small Distractions with a Magnetically Controlled Growing Rod for Early-Onset Scoliosis and Avoidance of the Law of Diminishing Returns
Authors: Cheung Jason Pui Yin , Bow Cora , Samartzis Dino , Kwan Kenny , Cheung Kenneth Man Chee
Published: January 2017

Purpose

To assess the effect of frequent small distractions with a magnetically controlled growing rod (MCGR) on spinal length gain and achieved distraction length in children with early-onset scoliosis (EOS), and to determine whether the law of diminishing returns applies to this group of patients with MCGR.

Methods

A consecutive series of 3 males and 4 females with EOS who underwent MCGR implantation at a mean age of 10.2 years and were followed up for a mean of 3.8 years were reviewed. Distraction was aimed at 2 mm monthly. The coronal Cobb angle, T1-S1 length gain, and achieved distraction length were measured at 6-monthly intervals.

Results

The mean total number of distractions was 31. Four of the patients had problems that may have affected distractions. The mean coronal Cobb angle improved post-operatively and was maintained throughout the follow-up period. The mean T1-S1 length gain and achieved distraction length varied over the follow-up period and did not diminish with repeated lengthening.

Conclusions

Frequent small distractions with the MCGR for EOS enable T1-S1 and achieved distraction length gain without significant reduction in gain after repeated lengthening.
Single-Stage Posterior Instrumentation for Progressive Tubercular Thoracic and Thoracolumbar Kyphosis
Authors: Ahsan Kamrul , Sakeb Najmus
Published: January 2017

Purpose

To review the outcome of single-stage posterior instrumentation for progressive tubercular thoracic and thoracolumbar kyphosis in 45 patients.

Methods

Records of 16 men and 29 women aged 20 to 59 (mean, 34.1) years who underwent single-stage posterior instrumentation for active thoracic (n=27) or thoracolumbar (n=18) tuberculosis by a single surgeon and were followed up for a minimum of 5 years were reviewed. Neurological status was evaluated using the Frankel grading system. Pain was assessed using the visual analogue score (VAS). Disability status was assessed using the Oswestry Disability Index (ODI). Outcome was graded according to the Kim and Lee criteria. Kyphosis at presentation, preoperation (after one month of conservative therapy), immediate postoperation, and 5-year follow-up was measured on radiographs to determine the kyphosis progression, correction of deformity, postoperative loss of correction, and residual deformity.

Results

Respectively for 27 and 18 patients with thoracic or thoracolumbar involvement, at 5 years the mean VAS score improved from 5.5 to 1.9 (p<0.001) and from 6.8 to 1.5 (p<0.001), whereas the mean ODI improved from 60.8 to 11.7 (p<0.001) and from 57.5 to 7.6 (p<0.001). The outcome was excellent in 17 and 11, good in 7 and 5, and fair in 3 and 2 patients, respectively. The mean kyphosis progression from presentation to preoperation was from 20.2° to 26.2° and from 10.3° to 14.1°, respectively, whereas the corresponding mean predicted kyphosis progression was from 15.5° to 48.1° and from 13.8° to 50.4°. The respective mean correction of deformity was −8.1° and −8.5°; the respective mean residual deformity was 4.1° and 6.8°; and the respective mean loss of correction at 5 years was 1.9 and 1.9. Two patients had a dural tear, and 3 patients had a transient root injury. Two diabetic patients had superficial wound infection. One patient had downward migration of one rod at 30 months but remained asymptomatic.

Conclusion

Single-stage posterior instrumentation combined with continued chemotherapy for a minimum 12 months is a viable option for early progressive thoracic and thoracolumbar tubercular kyphosis.
Effect of Cable Cerclage on Regional Blood Circulation in Rabbits: A Scintigraphic Study
Authors: Karakoyun Ozgur , Sahin Ertan , Erol Mehmet Fatih , Kariksiz Mesut , Kucukkaya Metin
Published: January 2017

Purpose

To evaluate changes in blood circulation of the femoral cortex in rabbits using scintigraphy before and after cable cerclage alone or combined with an intramedullary Kirschner wire.

Method

Ten New Zealand rabbits were used. For the right femur, a 2-mm-thick cable was placed around the mid-diaphyseal region and squeezed with a 400-N force and locked with a clip. For the left femur, a 1.8-mm Kirschner wire was inserted retrogradely into the medullary canal, and a 2-mm-thick cable was applied using the same technique. The blood perfusion ratio of the region of interest (ROI) before and after surgery was evaluated using scintigraphy.

Results

For the right femurs, the mean ROI perfusion ratio decreased by 45% from 2.51 to 1.37 after intervention (p=0.001). For the left femurs, the mean ROI perfusion ratio decreased by 56% from 2.12 to 0.92 after intervention (p<0.001). The mean ROI perfusion ratio post-intervention was higher in the right than left femurs (p=0.017).

Conclusion

Cable cerclage around the femoral cortex significantly decreased blood circulation in the area.
Use of a Magnetic Bone Nail for Lengthening of the Femur and Tibia
Authors: Karakoyun Ozgur , Sokucu Sami , Erol Mehmet Fatih , Kucukkaya Metin , Kabukcuoglu Yavuz Selim
Published: January 2017

Purpose

To report our experience with the PRECICE nail for limb lengthening in 23 patients.

Methods

Records of 15 female and 8 male patients aged 14 to 38 (mean, 23.6) years who underwent lengthening of the tibia (n=6) or femur (n=21) using the PRECICE nail were reviewed. The reasons for lengthening included trauma (n=7), hemihypertrophy (n=2), focal femoral deficiency (n=2), Ellis-van Creveld syndrome (n=1), hip septic arthritis sequelae (n=1), hereditary multiple exostosis (n=1), club foot sequela (n=1), congenital tibial pseudoarthrosis (n=1), fibrous dysplasia (n=1), idiopathic limb length discrepancy (n=7), and cosmetic (n=1).

Results

The mean follow-up duration was 20.72 months. The mean lengthening was 48.20 mm, and the mean acute angular correction was 15.5°. The mean time to full weight-bearing was 5.15 months, and the mean consolidation index was 1.12 months/cm. The mean maturation index was 0.78 months/cm. One patient had nail breakage during the consolidation phase. The nail was replaced by an intramedullary nail until consolidation, after which another PRECICE nail was used to treat the residual shortening. Eight patients had over-lengthening and the nails were driven back to the desired length. No patient had infection.

Conclusion

The PRECICE nail is a viable option for lengthening of the femur and tibia.