High-strength fully porous biomaterials built with additive manufacturing provide an exciting opportunity for load-bearing orthopedic applications. While factors controlling their mechanical and ...biological response have recently been the subject of intense research, the interplay between mechanical properties, bone ingrowth requirements, and manufacturing constraints, is still unclear. In this paper, we present two high-strength stretch-dominated topologies, the Tetrahedron and the Octet truss, as well as an intuitive visualization method to understand the relationship of cell topology, pore size, porosity with constraints imposed by bone ingrowth requirements and additive manufacturing. 40 samples of selected porosities are fabricated using Selective Laser Melting (SLM), and their morphological deviations resulting from SLM are assessed via micro-CT. Mechanical compression testing is used to obtain stiffness and strength properties, whereas bone ingrowth is assessed in a canine in vivo model at four and eight weeks. The results show that the maximum strength and stiffness ranged from 227.86±10.15 to 31.37±2.19MPa and 4.58±0.18 to 1.23±0.40GPa respectively, and the maximum 0.2% offset strength is almost 5 times stronger than that of tantalum foam. For Tetrahedron samples, bone ingrowth after four and eight weeks is 28.6%±11.6%, and 41.3%±4.3%, while for the Octet truss 35.5%±1.9% and 56.9%±4.0% respectively. This research is the first to demonstrate the occurrence of bone ingrowth into high-strength porous biomaterials which have higher structural efficiency than current porous biomaterials in the market.
We present two stretch-dominated cell topologies for porous biomaterials that can be used for load-bearing orthopaedic applications, and prove that they encourage bone ingrowth in a canine model. We also introduce an intuitive method to visualize and understand the relationship of cell topology, pore size, porosity with constraints imposed by bone ingrowth requirements and additive manufacturing. We show this strategy helps to gain insight into the interaction of exogenous implant factors and endogenous system factors that can affect the success of load-bearing orthopaedic devices.
The present study examined the prospective value of response expectancies (ie, pain, sleep) and behavioral outcome expectancies (ie, return to function) in the prediction of pain severity and ...functional limitations 12 months after total knee arthroplasty (TKA). The study sample consisted of 120 individuals (73 women, 47 men) with osteoarthritis of the knee who were scheduled for TKA. Measures of expectancies, pain severity, pain catastrophizing, pain-related fears of movement, and depression were completed prior to surgery. Participants also completed measures of pain severity and functional limitations 12 months following surgery. Analyses revealed that behavioral outcome expectancies were stronger predictors of follow-up pain and functional limitations than response expectancies. Consistent with previous research, analyses also revealed that pain catastrophizing, pain-related fear of movement, and depression predicted follow-up pain and function. In a multivariate analysis, only pain catastrophizing contributed significant unique variance to the prediction of follow-up pain and function. Behavioral outcome expectancies partially mediated the relation between catastrophizing and follow-up pain and function. The relation between catastrophizing and follow-up pain severity and functional limitations remained significant even when controlling for behavioral outcome expectancies. The results suggest that interventions designed to specifically target behavioral outcome expectancies and catastrophizing might improve post-surgical outcomes.
The primary objective of the present study was to examine the role of pain-related psychological factors in predicting pain and disability following Total Knee Arthroplasty (TKA). The study sample ...consisted of 75 (46 women, 29 men) individuals with osteoarthritis of the knee who were scheduled for TKA. Measures of pain severity, pain catastrophizing, depression, and pain-related fears of movement were completed prior to surgery. Participants completed measures of pain severity and self-reported disability 6 weeks following surgery. Consistent with previous research, cross-sectional analyses revealed significant correlations among measures of pre-surgical pain severity, pain catastrophizing, depression and pain-related fears of movement. Prospective analyses revealed that pre-surgical pain severity and pain catastrophizing were unique predictors of post-surgical pain severity (6-week follow-up). Pain-related fears of movement were predictors of post-surgical functional difficulties in univariate analyses, but not when controlling for pre-surgical co-morbidities (e.g. back pain). The results of this study add to a growing literature highlighting the prognostic value of psychological variables in the prediction of post-surgical health outcomes. The results support the view that the psychological determinants of post-surgical pain severity differ from the psychological determinants of post-surgical disability. The results suggest that interventions designed to specifically target pain-related psychological risk factors might improve post-surgical outcomes.
The restoration of the preoperative biomechanics of the hip, in particular leg length and femoral offset, are critical in restoring normal function and diminishing the risk of dislocation following ...hip arthroplasty. This study compares the consistency of arthroplasty and non-arthroplasty orthopedic surgeons in restoring the normal biomechanics of the hip when performing a hemiarthroplasty for the treatment of a femoral neck fracture.
We retrospectively reviewed the preoperative and postoperative digital radiographs of 175 hips that had a modular hemiarthroplasty for the treatment of a displaced femoral neck fracture at a Level 1 academic hospital. Fifty-two hips were treated by one of the three fellowship-trained arthroplasty surgeons (Group A), and 123 were treated by one of the nine non-arthroplasty fellowship-trained orthopedic surgeons (Group B).
Patients in Group A were more likely to have their femoral offset restored to normal than patients in Group B, both with respect to under correcting the offset (
= 0.031) and overcorrecting the offset (
= 0.010). Overall, there was no difference in restoration of leg lengths between the two groups (
= 0.869).
Following a hemiarthroplasty for a displaced femoral neck fracture, the normal biomechanics of the hip are more likely to be restored by an arthroplasty-trained surgeon than by a non-arthroplasty-trained surgeon. Identifying the inconsistency of non-arthroplasty surgeons and, to a lesser degree, arthroplasty surgeons in restoring hip biomechanics is important for sensitizing surgeons to rectify this in the future with appropriate templating and femoral implant selection.
Abstract Background Adult reconstructive surgery is an orthopedic subspecialty characterized by surgical tasks that are physical, repetitive, and require some degree of stamina from the surgeon. This ...can result strain and/or injury of the surgeon's musculoskeletal system. This study investigates the prevalence of work-related injuries among arthroplasty surgeons. Methods A modified version of the physical discomfort survey was sent to surgeon members of the Hip Society, the International Hip Society, and the Canadian Orthopedic Arthroplasty via email. One hundred and eighty-three surgeons completed the survey. Results Overall, 66.1% of the arthroplasty surgeons reported that they had experienced a work-related injury. The most common injuries that occurred were low back pain (28%), lateral epicondylitis of the elbow (14%), shoulder tendonitis (14%), lumbar disc herniation (13%), and wrist arthritis (12%). Overall, 27% of surgeons took time off from work because of the injury. As the number of disorders diagnosed increased, there was a significant increase in the incidence of requiring time off work because of the disorder ( P < .001) and also exacerbation of a previously diagnosed disorder ( P < .01). Factors that significantly increased the risk of the surgeon requiring time off because of the disorder were age >55 years, practicing for more than >20 years, and performing >100 total hip arthroplasty procedures per year ( P < .05). In addition, 31% of the orthopedic surgeons surveyed required surgery for their injury. Conclusion Although most studies concentrate on the importance of patient safety and thus the quality of the health care system, the surgeon's safety is also considered an integral part of this system's quality. This study highlights a high prevalence of musculoskeletal work-related injuries among arthroplasty surgeons and indicates the need for the identification of preventive measures directed toward improving the operative surgical environment and work ergonomics for the surgeons.
Total knee arthroplasty (TKA) is a highly effective procedure that yields reductions in pain and disability associated with end stage osteoarthritis (OA) of the knee. Quality of life instruments are ...frequently used to gauge the outcomes of total knee arthroplasty (TKA). However, research suggests that post-TKA reductions in symptom severity may not be the sole predictors of quality of life post-TKA. The primary objective of the present study was to examine the prognostic value of catastrophic thinking in health-related quality of life (HRQoL) judgments in patients with severe OA after TKA.
In this study we used a prospective cohort design to examine the value of pain catastrophizing in predicting HRQoL 1 year after TKA. Participants with advanced OA of the knee who were scheduled for TKA were recruited at one of three hospitals in Canada. The study sample consisted of 116 individuals (71 women, 45 men) who completed study questionnaires at their pre-surgical evaluation and 1 year after surgery. Hierarchical regression analysis was used to assess the unique contribution of pre-surgical pain catastrophizing to the prediction of post-surgical HRQoL judgments.
The results of the hierarchical regression equation revealed that the overall model was significant, F (9,106) = 8.3, p < 001, and accounted for 36.4% of the variance in the prediction of post-surgical physical component score of HRQoL. Pain catastrophizing was entered in the last step of the equation and contributed significant unique variance (β = -.35, p < .001) to the prediction of post-surgical physical component score of HRQoL above and beyond the variance accounted for by demographic variables, co-morbid health conditions, baseline HRQoL, and post-surgical reductions in pain, joint stiffness and physical disability.
The current findings highlight the importance of pre-surgical catastrophic cognitions in influencing HRQoL judgments after TKA. The findings suggest that psychosocial interventions designed to reduce pain catastrophizing before TKA might contribute to better quality of life outcomes following surgery.
Bioactive surface coatings have retained the attention of researchers and physicians due to their versatility and range of applications in orthopedics, particularly in infection prevention. ...Antibacterial metal nanoparticles (mNPs) are a promising therapeutic, with vast application opportunities on orthopedic implants. The current research aimed to construct a polyelectrolyte multilayer on a highly porous titanium implant using alternating thin film coatings of chitosan and alginate via the layer-by-layer (LbL) self-assembly technique, along with the incorporation of silver nanoparticles (AgNPs) or titanium dioxide nanoparticles (TiO2NPs), for antibacterial and osteoconductive activity. These mNPs were characterized for their physicochemical properties using quartz crystal microgravimetry with a dissipation system, nanoparticle tracking analysis, scanning electron microscopy, and atomic force microscopy. Their cytotoxicity and osteogenic differentiation capabilities were assessed using AlamarBlue and alkaline phosphatase (ALP) activity assays, respectively. The antibiofilm efficacy of the mNPs was tested against Staphylococcus aureus. The LbL polyelectrolyte coating was successfully applied to the porous titanium substrate. A dose-dependent relationship between nanoparticle concentration and ALP as well as antibacterial effects was observed. TiO2NP samples were also less cytotoxic than their AgNP counterparts, although similarly antimicrobial. Together, these data serve as a proof-of-concept for a novel coating approach for orthopedic implants with antimicrobial and osteoconductive properties.
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