Bioabsorbable versus titanium screws in anterior cruciate ligament reconstruction using hamstring autograft: a prospective, blinded, randomized controlled trial with 5-year follow-up

Background: Longer term studies of bioabsorbable screws for ACL reconstruction are reported, but results are specific to the exact screw material and design. Titanium and PLLA-HA screw outcomes have been compared only to 2 years. Purpose: The aim of this study was to compare the clinical and radiological outcomes of PLLAHA screw (BS) versus a titanium screw (TS), for hamstring tendon anterior cruciate ligament reconstruction over 5 years. We hypothesized that there are no differences in clinical scores, and tunnel widening, between the BS and the TS groups, and that the PLLA-HA screw as seen on MRI should show high grade resorption and ossification response over 5 years. Methods: 40 patients undergoing ACLR were randomized to receive either a PLLA-HA screw (BS group) or a Titanium screw (TS group) for ACL fixation. Blinded evaluation was performed at 2 & 5 years with IKDC & Lysholm knee score, KT-1000 arthrometer, single legged hop test, and MRI to evaluate tunnel and screw volumes, peri-screw ossification, graft integration and cyst formation. Results: There was no difference in any clinical outcome measure at 2 or 5 years between the 2 groups. At 2 years, the BS femoral tunnel was smaller than the TS tunnel (p=0.02) and at 5 years, there was no difference. At 2 years the femoral BS screw was a mean 76% of its original volume and by 5 years, 36%. At 2 years the tibial BS screw mean volume was 68% of its original volume and by 5 years, 46%. At 5 years BS group 88% of femoral tunnels and 56% of tibial tunnels demonstrated a significant ossification response. There was no increase in cyst formation in the BS group and no screw breakages. Conclusion: Our study has shown equivalent clinical results between BS and TS groups at 2 and 5 years. This PLLA-HA screw was not associated with increased tunnel widening or cyst formation when compared with the titanium screw. The PLLA-HA screw demonstrated progressive screw resorption and gradual, but incomplete ossification over 5 years

Catalytic Social Entrepreneurship to Combat Desperate Poverty: A Systems Approach

Any credible agenda that seeks to eradicate global poverty must seek to correct the structural injustices and inequities that cause and perpetuate desperate endemic poverty. Such an agenda must aim not merely to aid the poor with grants, welfare and subsidies, but it must primarily seek to enhance the capabilities, skills, access and opportunities of the marginalized to participate on more equitable terms, in the dynamic process of overall economic growth. We apply a systems approach to poverty, the latter itself being a pernicious system. Eradication of global desperate poverty and its unjust structural causes can be done through two concurrent systems-thinking based strategies: (a) micro catalytic social entrepreneurship that leads to catalytic innovations that alleviate poverty, and (b) macro social catalytic political entrepreneurship that radically innovates legislation or designs macro-policy intervention systems that can effectively dismantle existing unjust structures of social injustice and inequities – the causes that perpetuate endemic global poverty. Using the theories of catalytic innovations and the bottom of the pyramid, we focus on solution (a) as being feasible, viable and doable and in the long run having the potential for eradicating global desperate poverty. We also provide two case studies where solution (b) was effectively implemented. The main proposition of the paper is that the use of both micro- and macro- catalyst can help alleviate poverty in the world.   Keywords: Micro catalyst, macro catalyst, global poverty, system approach, catalytic innovation, macro-policy intervention

Use of a Distal Radius Endoprosthesis Following Resection of a Bone Tumour: A Case Report

Limited literature is available on the reconstruction of the distal radius using prosthetic replacement following resection of a bone tumour. We present the first reported case, in the English literature, of the use of an entirely metal endoprosthesis for the reconstruction of the distal radius. This case involves a 66-year-old male who was treated for giant cell tumour of the distal radius with surgical excision of the lesion and replacement of the defect using a predominantly titanium endoprosthesis. He was followed-up for 56 months following surgery and had a good functional outcome with no associated pain or complications. We propose that the use of a primarily titanium endoprosthesis for the reconstruction of a bone defect of the distal radius is a suitable alternative, providing good function of the forearm with satisfactory range of movement at the wrist and adequate pain relief

SARS-CoV-2-specific immune responses and clinical outcomes after COVID-19 vaccination in patients with immune-suppressive disease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune responses and infection outcomes were evaluated in 2,686 patients with varying immune-suppressive disease states after administration of two Coronavirus Disease 2019 (COVID-19) vaccines. Overall, 255 of 2,204 (12%) patients failed to develop anti-spike antibodies, with an additional 600 of 2,204 (27%) patients generating low levels (<380 AU ml−1). Vaccine failure rates were highest in ANCA-associated vasculitis on rituximab (21/29, 72%), hemodialysis on immunosuppressive therapy (6/30, 20%) and solid organ transplant recipients (20/81, 25% and 141/458, 31%). SARS-CoV-2-specific T cell responses were detected in 513 of 580 (88%) patients, with lower T cell magnitude or proportion in hemodialysis, allogeneic hematopoietic stem cell transplantation and liver transplant recipients (versus healthy controls). Humoral responses against Omicron (BA.1) were reduced, although cross-reactive T cell responses were sustained in all participants for whom these data were available. BNT162b2 was associated with higher antibody but lower cellular responses compared to ChAdOx1 nCoV-19 vaccination. We report 474 SARS-CoV-2 infection episodes, including 48 individuals with hospitalization or death from COVID-19. Decreased magnitude of both the serological and the T cell response was associated with severe COVID-19. Overall, we identified clinical phenotypes that may benefit from targeted COVID-19 therapeutic strategies

Multiple Multicast with Minimized Node Contention on Wormhole k-ary n-cube Networks

: This paper presents a new approach to minimize node contention while performing multiple multicast/broadcast on wormhole k-ary n-cube networks with overlapped destination sets. The existing multicast algorithms in the literature deliver poor performance under multiple multicast because these algorithms have been designed with only single multicast in mind. The new algorithms introduced in this paper do not use any global knowledge about the respective destination sets of the concurrent multicasts. Instead, only local information and source-specific partitioning approach are used. For systems supporting unicast message-passing a new SPUmesh (Source- Partitioned Umesh) algorithm is proposed and shown to be superior than the conventional Umesh algorithm [14] for multiple multicast. Two different algorithms, SQHL (Source-Quadrant Hierarchical Leader) and SCHL (Source-Centered Hierarchical Leader), are proposed for systems with multidestination message-passing and shown to be superior t..

Multicasting on Switch-based Irregular Networks using Multi-drop Path-based Multidestination Worms

: This paper presents a novel concept of multi-drop path-based multidestination message passing on switch-based irregular networks. First, the multi-drop mechanism is defined with an associated header encoding scheme, and this mechanism is used to develop path-based multidestination worms. Next, a method is proposed to identify valid multidestination paths on arbitrary irregular networks with a typical deadlock-free routing. Then, the deadlock-free property of multi-drop path-based worms is emphasized. Using the above concepts, three multicast algorithms are proposed: multi-drop path-based greedy (MDP-G), multi-drop path-based lessgreedy (MDP-LG), and multi-drop path-based binomial (MDP-B). The proposed algorithms are compared with each other and with the best unicast based algorithm, the CCO [5], for a range of system and technological parameters. The MDP-LG scheme is shown to be the best to implement multicast with reduced latency. Keywords: Interconnection network, collective commu..

Optimal Multicast with Packetization and Network Interface Support

: Most multicast algorithms proposed in the literature assume an arbitrarily long message being communicated as a single packet. Modern networks typically limit the size of the largest packet, and long messages are packetized and transmitted. Such networks also provide network interface support for nodes, which typically includes a coprocessor and memory, to implement the lower layers of the communication protocol. Such network interfaces can be programmed to support efficient multicasting to eliminate software overhead for higher layers during absorb and retransmit. In this paper, we present an optimal multicast algorithm for systems with such smart network interface support for packetization. Two implementations of smart network interface, the First-Child-First-Served (FCFS) and the First-Packet-First-Served (FPFS), are studied and compared. It is shown that the FPFS network interface support is more practical and efficient. Next, the multicast latency is modeled for the FPFS impleme..