Risk factors for femoral stem fracture following total hip arthroplasty: a systematic review and meta analysis.

BACKGROUND: Femoral stem fracture following total hip arthroplasty (THA) is an infrequent but nevertheless devastating complication, with an increasing worldwide prevalence as demand for primary THA continues to increase. The aim of this study was to perform a systematic review and meta-analysis of risk factors for femoral stem fracture to help identify at risk patients. METHODS: A systematic search was conducted on EMBASE, MEDLINE and AMED to identify relevant studies. Data regarding study design, source, population, intervention, and outcomes was collated. Data extraction was performed on a custom form generated using Cochrane recommended methodology and analysis of risk factors performed including odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: A total of 15 studies reporting a total of 402 stem fractures in 49 723 THAs were identified. The median time from index procedure to stem fracture was 68 months (IQR 42.5-118) whilst mean age at index surgery was 61.8 years (SD 6.9). Male gender (OR = 3.27, 95% CI = 2.59-4.13, p < 0.001), patient weight above 80 kg (OR = 3.55, 95% CI = 2.88-4.37, p < 0.001), age under 63 years (OR = 1.22, 95% CI = 1.01-1.49, p < 0.001), varus stem alignment (OR = 5.77, 95% CI = 3.83-8.7, p < 0.001), use of modular implants (OR = 1.95, 95% CI = 1.56-2.44, p < 0.01) and undergoing revision arthroplasty (OR = 3.33, 95% CI = 2.70-4.1, p < 0.001) were significant risk factors for prosthetic stem fracture. A risk window of 15 years post-surgery was identified. CONCLUSIONS: This review concludes that patient weight, younger age, male sex, varus stem alignment, revision arthroplasty and use of modular stems are significant risk factors for femoral stem fracture. Modifying these risk factors where possible may help reduce incidence of femoral stem fracture in at risk patients.

The Olympia anatomic polished cemented stem is associated with a high survivorship, excellent hip-specific functional outcome, and high satisfaction levels: follow-up of 239 consecutive patients beyond 15 years.

INTRODUCTION: The Olympia femoral stem is a stainless steel, anatomically shaped, polished and three-dimensionally tapered implant designed for use in cemented total hip arthroplasty (THA). The primary aim of this study was to determine the long-term survivorship, radiographic outcome, and patient-reported outcome measures (PROMs) of the Olympia stem. PATIENTS AND METHODS: Between May 2003 and December 2005, 239 patients (264 THAs) underwent a THA with an Olympia stem in our institution. Patient-reported outcome measures were assessed using the Oxford Hip Score (OHS), EuroQol-5 dimensions (EQ-5D) score, and patient satisfaction at mean 10 years following THA. Patient records and radiographs were then reviewed at a mean of 16.5 years (SD 0.7, 15.3-17.8) following THA to identify occurrence of complications or revision surgery for any cause following surgery. Radiographs were assessed for lucent lines and lysis according to Gruen's zones RESULTS: Mean patient age at surgery was 68.0 years (SD 10.9, 31-93 years). There were 156 women (65%, 176 THAs). Osteoarthritis was the indication for THA in 204 patients (85%). All cause stem survivorship at 10 years was 99.2% (95% confidence interval [CI], 97.9%-100%) and at 15 years was 97.5% (94.6%-100%). The 15-year stem survival for aseptic loosening was 100%. Analysis of all-cause THA failure demonstrated a survivorship of 98.5% (96.3%-100%) at 10 years and 95.9% (92.4%-99.4%) at 15 years. There were 9 THAs with non-progressive lucent lines in a single Gruen zone and 3 had lines in two zones, and no patient demonstrated signs for lysis. At a mean of 10-year (SD 0.8, 8.7-11.3) follow-up, mean OHS was 39 (SD 10.3, range 7-48) and 94% of patients reported being very satisfied or satisfied with their THA. CONCLUSIONS: The Olympia stem demonstrated excellent 10-year PROMs and very high rates of stem survivorship at final follow-up beyond 15 years.

Return to Work Following Total Knee and Hip Arthroplasty: The Effect of Patient Intent and Preoperative Work Status.

BACKGROUND: The ability of total knee and hip arthroplasty (TKA/THA) to facilitate return to work (RTW) when it is the patient's preoperative intent to do so remains unclear. We aimed at determining whether TKA/THA facilitated RTW in patients of working age who intended to return. METHODS: This is a prospective cohort study of 173 consecutive patients <65 years of age, undergoing unilateral TKA (n = 82: median age 58; range, 39-65; 36 [43.9%] male) or THA (n = 91: median age 59; range, 34-65; 42 [46.2%] male) during 2018. Oxford knee/hip scores, Oxford-Activity and Participation Questionnaire, and EuroQol-5 dimension (EQ-5D) scores were measured preoperatively and at 1 year when an employment questionnaire was also completed. RESULTS: Of patients who intended to RTW, 44 of 52 (84.6%) RTW by 1 year following TKA (at mean 14.8 ± 8.4 weeks) and 53 of 60 (88.3%) following THA (at mean 13.6 ± 7.5 weeks). Failure to RTW despite intent was associated with job physicality for TKA (P = .004) and negative preoperative EQ-5D for THA (P = .01). In patients unable to work before surgery due to joint disease, fewer RTW: 4 of 21 (19.0%) after TKA; and 6 of 17 (35.3%) after THA. Preoperative Oxford knee score >18.5 predicted RTW with 74% sensitivity (P < .001); preoperative Oxford hip score >19.5 predicted RTW with 75% sensitivity (P < .001). Preoperative EQ-5D indices were similarly predictive (P < .001). CONCLUSION: In this United Kingdom study, preoperative intent to RTW was the most powerful predictor of actual RTW following TKA/THA. Where patients intend to RTW following TKA/THA, 85% RTW following TKA and 88% following THA.

Gender and Preoperative Function Predict Physical Activity Levels After Revision Total Knee Arthroplasty.

BACKGROUND: The incidence of revision total knee arthroplasty (TKA) is projected to increase 6-fold worldwide by 2030. As the number of younger, physically active revision TKA patients increases in future, understanding factors influencing postoperative function will be increasingly important to help counsel patients. The primary aim of this study was to examine factors influencing return to physical activity following revision TKA. METHODS: Patients who had undergone tibiofemoral revision between 2003 and 2013 at a single UK teaching hospital were retrospectively identified from a prospectively collected arthroplasty database. Preoperative activity level (University of California, Los Angeles [UCLA] score), patient demographics, indication, implant used, and Oxford Knee Scores (OKSs) were recorded in the database. At a mean follow-up of 3.9 years (standard deviation, 2.2), UCLA score, OKS, EuroQol-5 Dimension Score (EQ-5D), satisfaction, complications, and WORQ scores (Work, Osteoarthritis and Joint-Replacement Questionnaire) were sampled via postal questionnaire. Patient experience of complications and related surgery was also identified from healthcare records. Univariate and multivariate analyses were performed. RESULTS: Responses were received from 112 revision TKAs (112 patients; mean age, 71 years). Mean UCLA activity scores improved from preoperative levels (P < .001): activity levels improved in 47% of patients with 58% engaging in moderate or more intensive activities (UCLA score ≥5). Postoperative activity level was independently predicted by male gender (P = .042) and preoperative UCLA score (P < .001). Increasing social deprivation was associated with inferior UCLA (P = .005), EQ-5D (P < .005), and OKS (P = .006) scores. Indication, implant type, and patient body mass index did not affect functional outcome or satisfaction (P > .05). Patients <65 years old were more likely to be dissatisfied (P = .009), and patients aged ≤55 years were more likely to report difficulties with WORQ criteria (P < .05). CONCLUSION: Although 90% of patients maintain activity levels following revision TKA, less than half increase levels and this is predicted by male sex and pre-revision activity level.

Microfluidics-Based Fabrication of Cell-Laden Hydrogel Microfibers for Potential Applications in Tissue Engineering.

Fibrous hydrogel scaffolds have recently attracted increasing attention for tissue engineering applications. While a number of approaches have been proposed for fabricating microfibers, it remains difficult for current methods to produce materials that meet the essential requirements of being simple, flexible and bio-friendly. It is especially challenging to prepare cell-laden microfibers which have different structures to meet the needs of various applications using a simple device. In this study, we developed a facile two-flow microfluidic system, through which cell-laden hydrogel microfibers with various structures could be easily prepared in one step. Aiming to meet different tissue engineering needs, several types of microfibers with different structures, including single-layer, double-layer and hollow microfibers, have been prepared using an alginate-methacrylated gelatin composite hydrogel by merely changing the inner and outer fluids. Cell-laden single-layer microfibers were obtained by subsequently seeding mouse embryonic osteoblast precursor cells (MC3T3-E1) cells on the surface of the as-prepared microfibers. Cell-laden double-layer and hollow microfibers were prepared by directly encapsulating MC3T3-E1 cells or human umbilical vein endothelial cells (HUVECs) in the cores of microfibers upon their fabrication. Prominent proliferation of cells happened in all cell-laden single-layer, double-layer and hollow microfibers, implying potential applications for them in tissue engineering.

Return to activity following revision total hip arthroplasty.

BACKGROUND: Demand for revision total hip arthroplasty (RTHA) continues to grow worldwide and is expected to more than double within the next 1-2 decades. The primary aim of this study was to examine return to function following revision THA in a UK population. PATIENTS AND METHODS: We assessed 118 patients (132 RTHAs, mean age 65 years SD 13, range 23-88) at a mean follow-up of 7.9 years (SD 4.4) postoperatively. Preoperative age, gender, BMI, social deprivation, operative indication, comorbidities, activity level (UCLA score) and Oxford Hip Scores (OHS) were recorded. Postoperative UCLA score, OHS, EQ-5D, satisfaction levels and performance in activities of daily living (ADLs) were obtained and univariate and multivariate analysis performed. RESULTS: Mean UCLA activity score improved following RTHA (p < 0.001): UCLA activity score improved in 37% and was unchanged in 50%; 49% of patients engaged in at least moderate level activities (UCLA score ≥ 6). Patient BMI, gender, age and reason for revision did not influence levels of pain, stiffness or activity at follow-up. Preoperative UCLA activity scores (p < 0.001) independently predicted long-term UCLA scores. Independent predictors (p < 0.05) of poor hip-specific function (OHS) following revision included social deprivation, revision for periprosthetic fracture and lower preoperative OHS. Difficulties with ADLs were associated with increasing deprivation, ≥ 3 comorbidities, and revision for periprosthetic fracture or infection (p < 0.05). Overall, 79% of patients remained satisfied or very satisfied following revision THA. Following RTHA, 10% suffered a dislocation and 13% required reoperation for complications. CONCLUSION: Revision THA facilitates long-term return to preoperative levels of physical activity in the majority of patients, though activity levels increase in one-third only. Overall over three-quarters are satisfied with their outcome, but revision for periprosthetic fracture or dislocation gives the worse overall outcomes and lower satisfaction levels.

Clostridium septicum arthroplasty infection: beware of occult aortitis and malignancy.

INTRODUCTION: The Clostridia species are responsible for life-threatening conditions such as tetanus, botulism and gas gangrene. Clostridium septicum is a rare cause of clinical infection, accounting for less than 1% of blood culture samples that test positive for Clostridia. However, C. septicum bacteraemia is associated with greater than 60% mortality and in over 80% of cases is associated with an underlying malignancy. CASE PRESENTATION: We present a review of the literature and the first case of an acute arthroplasty infection and concurrent infective aortitis caused by this organism in the absence of an identified underlying malignancy. Early diagnosis and multi-disciplinary input resulted in the patient surviving a rare and potentially fatal infective aortitis and septic arthritis. CONCLUSION: This case demonstrates the importance of early systemic investigation to exclude occult infective aortitis in C. septicum infection. The key role of multi-disciplinary input into the management of this often fatal infection is also discussed along with the requirement to exclude occult gastrointestinal and haematological malignancy.

3D biofabrication for soft tissue and cartilage engineering.

Soft tissue injuries (STIs) affect patients of all age groups and represent a common worldwide clinical problem, resulting from conditions including trauma, infection, cancer and burns. Within the spectrum of STIs a mixture of tissues can be injured, ranging from skin to underlying nerves, blood vessels, tendons and cartilaginous tissues. However, significant limitations affect current treatment options and clinical demand for soft tissue and cartilage regenerative therapies continues to rise. Improving the regeneration of soft tissues has therefore become a key area of focus within tissue engineering. As an emerging technology, 3D bioprinting can be used to build complex soft tissue constructs "from the bottom up," by depositing cells, growth factors, extracellular matrices and other biomaterials in a layer-by-layer fashion. In this way, regeneration of cartilage, skin, vasculature, nerves, tendons and other bodily tissues can be performed in a patient specific manner. This review will focus on recent use of 3D bioprinting and other biofabrication strategies in soft tissue repair and regeneration. Biofabrication of a variety of soft tissue types will be reviewed following an overview of available cell sources, bioinks and bioprinting techniques.

Microfluidic Fabrication of Biomimetic Helical Hydrogel Microfibers for Blood-Vessel-on-a-Chip Applications.

Nature has created many perfect helical microstructures, including DNA, collagen fibrils, and helical blood vessels, to achieve unique physiological functions. While previous studies have developed a number of microfabrication strategies, the preparation of complex helical structures and cell-laden helical structures for biomimetic applications remains challenging. In this study, a one-step microfluidics-based methodology is presented for preparing complex helical hydrogel microfibers and cell-laden helical hydrogel microfibers. Several types of complex helical structures, including multilayer helical microfibers and superhelical hollow microfibers with helical channels, are prepared by simply tuning the flow rates or modifying the geometry of microfluidic device. With the decent perfusability, the hollow microfibers may simulate the structural characteristics of helical blood vessels and create swirling blood flow in a blood-vessel-on-chip setup. Such hydrogel-based helical microstructures may potentially be used in areas such as blood vessel tissue engineering, organ-on-chips, drug screening, and biological actuators.

3D bioprinting of mature bacterial biofilms for antimicrobial resistance drug testing.

The potential to bioprint and study 3D bacterial biofilm constructs could have great clinical significance at a time when antimicrobial resistance is rising to dangerously high levels worldwide. In this study, clinically relevant bacterial species including Escherichia coli, Staphylococcus aureus (MSSA), Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa were 3D bioprinted using a double-crosslinked alginate bioink to form mature bacteria biofilms, characterized by confocal laser scanning microscopy (CLSM) and fluorescent staining. Solid and porous bacteria-laden constructs were reproducibly bioprinted with thicknesses ranging from 0.25 to 4 mm. We demonstrated 3D bioprinting of thicker biofilms (>4 mm) than found in currently available in vitro models. Bacterial viability was excellent in the bioprinted constructs, with CLSM observation of bacterial biofilm production and maturation possible for at least 28 d in culture. Importantly, we observed the complete five-step biofilm life cycle in vitro following 3D bioprinting for the first time, suggesting the formation of mature 3D bioprinted biofilms. Bacterial growth was faster in thinner, more porous constructs whilst constructs crosslinked with BaCl2 concentrations of above 10 mM had denser biofilm formation. 3D MRSA and MSSA biofilm constructs were found to show greater resistance to antimicrobials than corresponding two-dimensional (2D) cultures. Thicker 3D E. coli biofilms had greater resistance to tetracycline than thinner constructs over 7 d of treatment. Our methodology allowed for the precise 3D bioprinting of self-supporting 3D bacterial biofilm structures that developed biofilms during extended culture. 3D biofilm constructs containing bacterial biofilms produce a model with much greater clinical relevance compared to 2D culture models and we have demonstrated their use in antimicrobial testing.

Trauma theatre productivity - Does the individual surgeon, anaesthetist or consultant presence matter?

INTRODUCTION: With rising NHS clinical and financial demands, improving theatre efficiency is essential to maintain quality of patient care. Consistent teams and consultant presence have been shown to improve outcomes and productivity in elective orthopaedic surgery. The aim of this study was to investigate the impact on trauma theatre productivity of different surgeons and anaesthetists working together in a Major Trauma Centre. The influence of consultant presence and weekend operating on productivity was also considered. METHODS: Data relating to a single orthopaedic trauma theatre was gathered retrospectively for a two-year period. Variables including orthopaedic and anaesthetic consultant presence, number and complexity of operations performed and procedure start times were collected for daily trauma lists. Individual anaesthetic and orthopaedic consultants were compared by productivity outcomes. The impact of surgeons operating more frequently with one anaesthetist was also examined. RESULTS: Data relating to 2384 patients undergoing a total of 2787 procedures was collected. Orthopaedic consultant presence at the first surgical case (p < 0.05) and for 50% or greater of cases (p < 0.05) lead to higher mean number of cases performed per list and reduced turnaround time. Despite working with a significantly higher number of different consultant anaesthetists (p < 0.001) in year two, the productivity of surgeons as judged by list start time, total cases per list and total operating time was not significantly affected. Significantly earlier start times (p < 0.001) and shorter turnaround times (p < 0.001) at weekends led to maintained productivity despite shorter theatre time. No significant difference in productivity was found when comparing individual anaesthetic and orthopaedic consultants. Productivity was not significantly increased by surgeons operating more frequently with one individual anaesthetist. CONCLUSION: In the setting of an acute trauma theatre, orthopaedic consultant presence led to increased productivity. Furthermore, individual surgeon and anaesthetist pairings had no effect on overall productivity. Future efforts to improve productivity should focus on achieving earlier start times, consultant supervision of lists and reduced turnaround times between cases.

3D bioactive composite scaffolds for bone tissue engineering.

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed.