Aims. In the UK, the agricultural, military, and construction sectors have stringent rules about the use of hearing protection due to the risk of noise-induced hearing loss. Orthopaedic staff may also be at risk due to the use of power tools. The UK Health and Safety Executive (HSE) have clear standards as to what are deemed acceptable occupational levels of noise on A-weighted and C-weighted scales. The aims of this review were to assess the current evidence on the testing of exposure to noise in orthopaedic operating theatres to see if it exceeds these regulations. Methods. A search of PubMed and EMBASE databases was conducted using PRISMA guidelines. The review was registered prospectively in PROSPERO. Studies which assessed the exposure to noise for orthopaedic staff in operating theatres were included. Data about the exposure to noise were extracted from these studies and compared with the A-weighted and C-weighted acceptable levels described in the HSE regulations. Results. A total of 15 studies were deemed eligible. These included a total of 386 orthopaedic operations and the use of 64 orthopaedic instruments. A total of 294 operations (76%) and 45 instruments (70%) exceeded the regulations on an A-weighted scale, and 22% (10 of 46) of operations exceeded the maximum C-weighted peak acceptable level of noise. Noise-induced hearing loss was reported in 28 of 55 orthopaedic staff members (50.9%). Conclusion. Safe levels of noise can be exceeded in orthopaedic operations, and when using orthopaedic instruments. Employers have clear policies about exposure to noise in the workplace but have yet to identify orthopaedic theatres as a potential at-risk area. Orthopaedic staff need education, monitoring, and protection, while employers should consider regular assessments of staff in orthopaedic theatres and offer methods to prevent noise-induced hearing loss. Cite this article: Bone Joint J 2023;105-B(6):602–609

Aims. Evidence exists of a consistent decline in the value and time that medical schools place upon their undergraduate orthopaedic placements. This limited exposure to trauma and orthopaedics (T&O) during medical school will be the only experience in the speciality for the majority of doctors. This review aims to provide an overview of undergraduate orthopaedic training in the UK. Methods. This review summarizes the relevant literature from the last 20 years in the UK. Articles were selected from database searches using MEDLINE, EMBASE, ERIC, Cochrane, and Web of Science. A total of 16 papers met the inclusion criteria. Results. The length of exposure to T&O is declining; the mean total placement duration of two to three weeks is significantly less than the four- to six-week minimum advised by most relevant sources. The main teaching methods described in the literature included didactic lectures, bedside teaching, and small group case-based discussions. Students preferred interactive, blended learning teaching styles over didactic methods. This improvement in satisfaction was reflected in improvements in student assessment scores. However, studies failed to assess competencies in clinical skills and examinations, which is consistent with the opinions of UK foundation year doctors, approximately 40% of whom report a “poor” understanding of orthopaedics. Furthermore, the majority of UK doctors are not exposed to orthopaedics at the postgraduate level, which only serves to amplify the disparity between junior and generalist knowledge, and the standards expected by senior colleagues and professional bodies. Conclusion. There is a deficit in undergraduate orthopaedic training within the UK which has only worsened in the last 20 years, leaving medical students and foundation doctors with a potentially significant lack of orthopaedic knowledge. Cite this article: Bone Jt Open 2022;3(7):549–556

Aims. Preprint servers allow authors to publish full-text manuscripts or interim findings prior to undergoing peer review. Several preprint servers have extended their services to biological sciences, clinical research, and medicine. The purpose of this study was to systematically identify and analyze all articles related to Trauma & Orthopaedic (T&O) surgery published in five medical preprint servers, and to investigate the factors that influence the subsequent rate of publication in a peer-reviewed journal. Methods. All preprints covering T&O surgery were systematically searched in five medical preprint servers (medRxiv, OSF Preprints, Preprints.org, PeerJ, and Research Square) and subsequently identified after a minimum of 12 months by searching for the title, keywords, and corresponding author in Google Scholar, PubMed, Scopus, Embase, Cochrane, and the Web of Science. Subsequent publication of a work was defined as publication in a peer-reviewed indexed journal. The rate of publication and time to peer-reviewed publication were assessed. Differences in definitive publication rates of preprints according to geographical origin and level of evidence were analyzed. Results. The number of preprints increased from 2014 to 2020 (p < 0.001). A total of 38.6% of the identified preprints (n = 331) were published in a peer-reviewed indexed journal after a mean time of 8.7 months (SD 5.4 (1 to 27)). The highest proportion of missing subsequent publications was in the preprints originating from Africa, Asia/Middle East, and South America, or in those that covered clinical research with a lower level of evidence (p < 0.001). Conclusion. Preprints are being published in increasing numbers in T&O surgery. Depending on the geographical origin and level of evidence, almost two-thirds of preprints are not subsequently published in a peer-reviewed indexed journal after one year. This raises major concerns regarding the dissemination and persistence of potentially wrong scientific work that bypasses peer review, and the orthopaedic community should discuss appropriate preventive measures. Cite this article: Bone Jt Open 2022;3(7):582–588

Aims. Sarcopenia is characterized by a generalized progressive loss of skeletal muscle mass, strength, and physical performance. This systematic review primarily evaluated the effects of sarcopenia on postoperative functional recovery and mortality in patients undergoing orthopaedic surgery, and secondarily assessed the methods used to diagnose and define sarcopenia in the orthopaedic literature. Methods. A systematic search was conducted in MEDLINE, EMBASE, and Google Scholar databases according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Studies involving sarcopenic patients who underwent defined orthopaedic surgery and recorded postoperative outcomes were included. The quality of the criteria by which a diagnosis of sarcopenia was made was evaluated. The quality of the publication was assessed using Newcastle-Ottawa Scale. Results. A total of 365 studies were identified and screened, 26 full-texts were reviewed, and 19 studies were included in the review. A total of 3,009 patients were included, of whom 2,146 (71%) were female and 863 (29%) were male. The mean age of the patients was 75.1 years (SD 7.1). Five studies included patients who underwent spinal surgery, 13 included hip or knee surgery, and one involved patients who underwent fixation of a distal radial fixation. The mean follow-up was 1.9 years (SD 1.9; 5 days to 5.6 years). There was wide heterogeneity in the measurement tools which were used and the parameters for the diagnosis of sarcopenia in the studies. Sarcopenia was associated with at least one deleterious effect on surgical outcomes in all 19 studies. The postoperative rate of mortality was reported in 11 studies (57.9%) and sarcopenia was associated with poorer survival in 73% (8/11) of these. The outcome was most commonly assessed using the Barthel Index (4/19), and sarcopenic patients recorded lower scores in 75% (3/4) of these. Sarcopenia was defined using the gold-standard three parameters (muscle strength, muscle quantity or quality, and muscle function) in four studies (21%), using two parameters in another four (21%) and one in the remaining 11 (58%). The methodological quality of the studies was moderate to high. Conclusion. There is much heterogeneity in the reporting of the parameters which are used for the diagnosis of sarcopenia, and evaluating the outcome of orthopaedic surgery in sarcopenic patients. However, what data exist suggest that sarcopenia impairs recovery and increases postoperative mortality, especially in patients undergoing emergency surgery. Further research is required to develop processes that allow the accurate diagnosis of sarcopenia in orthopaedics, which may facilitate targeted pre- and postoperative interventions that would improve outcomes. Cite this article: Bone Joint J 2022;104-B(3):321–330

Aims. Biofilm-related infection is a major complication that occurs in orthopaedic surgery. Various treatments are available but efficacy to eradicate infections varies significantly. A systematic review was performed to evaluate therapeutic interventions combating biofilm-related infections on in vivo animal models. Methods. Literature research was performed on PubMed and Embase databases. Keywords used for search criteria were “bone AND biofilm”. Information on the species of the animal model, bacterial strain, evaluation of biofilm and bone infection, complications, key findings on observations, prevention, and treatment of biofilm were extracted. Results. A total of 43 studies were included. Animal models used included fracture-related infections (ten studies), periprosthetic joint infections (five studies), spinal infections (three studies), other implant-associated infections, and osteomyelitis. The most common bacteria were Staphylococcus species. Biofilm was most often observed with scanning electron microscopy. The natural history of biofilm revealed that the process of bacteria attachment, proliferation, maturation, and dispersal would take 14 days. For systemic mono-antibiotic therapy, only two of six studies using vancomycin reported significant biofilm reduction, and none reported eradication. Ten studies showed that combined systemic and topical antibiotics are needed to achieve higher biofilm reduction or eradication, and the effect is decreased with delayed treatment. Overall, 13 studies showed promising therapeutic potential with surface coating and antibiotic loading techniques. Conclusion. Combined topical and systemic application of antimicrobial agents effectively reduces biofilm at early stages. Future studies with sustained release of antimicrobial and biofilm-dispersing agents tailored to specific pathogens are warranted to achieve biofilm eradication. Cite this article: Bone Joint Res 2022;11(10):700–714

Aims. The follow-up interval of a study represents an important aspect that is frequently mentioned in the title of the manuscript. Authors arbitrarily define whether the follow-up of their study is short-, mid-, or long-term. There is no clear consensus in that regard and definitions show a large range of variation. It was therefore the aim of this study to systematically identify clinical research published in high-impact orthopaedic journals in the last five years and extract follow-up information to deduce corresponding evidence-based definitions of short-, mid-, and long-term follow-up. Methods. A systematic literature search was performed to identify papers published in the six highest ranked orthopaedic journals during the years 2015 to 2019. Follow-up intervals were analyzed. Each article was assigned to a corresponding subspecialty field: sports traumatology, knee arthroplasty and reconstruction, hip-preserving surgery, hip arthroplasty, shoulder and elbow arthroplasty, hand and wrist, foot and ankle, paediatric orthopaedics, orthopaedic trauma, spine, and tumour. Mean follow-up data were tabulated for the corresponding subspecialty fields. Comparison between means was conducted using analysis of variance. Results. Of 16,161 published articles, 590 met the inclusion criteria. Of these, 321 were of level IV evidence, 176 level III, 53 level II, and 40 level I. Considering all included articles, a long-term study published in the included high impact journals had a mean follow-up of 151.6 months, a mid-term study of 63.5 months, and a short-term study of 30.0 months. Conclusion. The results of this study provide evidence-based definitions for orthopaedic follow-up intervals that should provide a citable standard for the planning of clinical studies. A minimum mean follow-up of a short-term study should be 30 months (2.5 years), while a mid-term study should aim for a mean follow-up of 60 months (five years), and a long-term study should aim for a mean of 150 months (12.5 years). Level of Evidence: Level I. Cite this article: Bone Jt Open 2021;2(5):344–350

Aims. Gender bias and sexual discrimination (GBSD) have been widely recognized across a range of fields and are now part of the wider social consciousness. Such conduct can occur in the medical workplace, with detrimental effects on recipients. The aim of this review was to identify the prevalence and impact of GBSD in orthopaedic surgery, and to investigate interventions countering such behaviours. Methods. A systematic review was conducted by searching Medline, EMCARE, CINAHL, PsycINFO, and the Cochrane Library Database in April 2020, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to which we adhered. Original research papers pertaining to the prevalence and impact of GBSD, or mitigating strategies, within orthopaedics were included for review. Results. Of 570 papers, 27 were eligible for inclusion. These were published between 1998 and 2020. A narrative review was performed in light of the significant heterogeneity displayed by the eligible studies. A total of 13 papers discussed the prevalence of GBSD, while 13 related to the impact of these behaviours, and six discussed mitigating strategies. GBSD was found to be common in the orthopaedic workplace, with all sources showing women to be the subjects. The impact of this includes poor workforce representation, lower salaries, and less career success, including in academia, for women in orthopaedics. Mitigating strategies in the literature are focused on providing female role models, mentors, and educational interventions. Conclusion. GBSD is common in orthopaedic surgery, with a substantial impact on sufferers. A small number of mitigating strategies have been tested but these are limited in their scope. As such, the orthopaedic community is obliged to participate in more thoughtful and proactive strategies that mitigate against GBSD, by improving female recruitment and retention within the specialty. Cite this article: Bone Joint J 2020;102-B(11):1446–1456

Aims. Computer-based applications are increasingly being used by orthopaedic surgeons in their clinical practice. With the integration of technology in surgery, augmented reality (AR) may become an important tool for surgeons in the future. By superimposing a digital image on a user’s view of the physical world, this technology shows great promise in orthopaedics. The aim of this review is to investigate the current and potential uses of AR in orthopaedics. Materials and Methods. A systematic review of the PubMed, MEDLINE, and Embase databases up to January 2019 using the keywords ‘orthopaedic’ OR ‘orthopedic AND augmented reality’ was performed by two independent reviewers. Results. A total of 41 publications were included after screening. Applications were divided by subspecialty: spine (n = 15), trauma (n = 16), arthroplasty (n = 3), oncology (n = 3), and sports (n = 4). Out of these, 12 were clinical in nature. AR-based technologies have a wide variety of applications, including direct visualization of radiological images by overlaying them on the patient and intraoperative guidance using preoperative plans projected onto real anatomy, enabling hands-free real-time access to operating room resources, and promoting telemedicine and education. Conclusion. There is an increasing interest in AR among orthopaedic surgeons. Although studies show similar or better outcomes with AR compared with traditional techniques, many challenges need to be addressed before this technology is ready for widespread use. Cite this article: Bone Joint J 2019;101-B:1479–1488

Aims. The aim of this study was to assess the quality and scope of the current cost-effectiveness analysis (CEA) literature in the field of hand and upper limb orthopaedic surgery. Materials and Methods. We conducted a systematic review of MEDLINE and the CEA Registry to identify CEAs that were conducted on or after 1 January 1997, that studied a procedure pertaining to the field of hand and upper extremity surgery, that were clinical studies, and that reported outcomes in terms of quality-adjusted life-years. We identified a total of 33 studies that met our inclusion criteria. The quality of these studies was assessed using the Quality of Health Economic Analysis (QHES) scale. Results. The mean total QHES score was 82 (high-quality). Over time, a greater proportion of these studies have demonstrated poorer QHES quality (scores < 75). Lower-scoring studies demonstrated several deficits, including failures in identifying reference perspectives, incorporating comparators and sensitivity analyses, discounting costs and utilities, and disclosing funding. Conclusion. It will be important to monitor the ongoing quality of CEA studies in orthopaedics and ensure standards of reporting and comparability in accordance with Second Panel recommendations. Cite this article: Bone Joint J 2018;100-B:1416–23

Aims. The aims of this systematic review were to describe the quantity and methodological quality of meta-analyses in orthopaedic surgery published during the last 17 years. Materials and Methods. MEDLINE, EMBASE, and PubMed, between 1 January 2000 and 31 December 2016, were searched for meta-analyses in orthopaedic surgery dealing with at least one surgical intervention. Meta-analyses were included if the interventions involved a human muscle, ligament, bone or joint. Results. A total of 392 meta-analyses met eligibility criteria, for which the mean AMSTAR quality score was 7.1/11. There was a positive correlation between the year of publication and the quality of the meta-analysis (r = 0.238, p < 0.001). Between 2000 and 2011, the mean AMSTAR score corresponded to that of a medium quality review. However, between 2012 and 2016, the mean scores have been consistently equivalent to those of a high-quality review. The number of meta-analyses published increased 10-fold between 2005 and 2014. Conclusion. The quantity and quality of meta-analyses in orthopaedic surgery which have been published has increased, reaching a plateau in 2012. Methodological flaws remain to be addressed in future meta-analyses in order to continue increasing the quality of the orthopaedic literature. Cite this article: Bone Joint J 2018;100-B:1270–4

Aims

Perthes' disease (PD) is a relatively rare syndrome of idiopathic osteonecrosis of the proximal femoral epiphysis. Treatment for Perthes' disease is controversial due to the many options available, with no clear superiority of one treatment over another. Despite having few evidence-based approaches, many patients with Perthes' disease are managed surgically. Positive outcome reporting, defined as reporting a study variable producing statistically significant positive (beneficial) results, is a phenomenon that can be considered a proxy for the strength of science. This study aims to conduct a systematic literature review with the hypothesis that positive outcome reporting is frequent in studies on the treatment of Perthes' disease.

Aims

To determine whether obesity and malnutrition have a synergistic effect on outcomes from skeletal trauma or elective orthopaedic surgery.

Aims. As an increasing number of female surgeons are choosing orthopaedics, it is important to recognize the impact of pregnancy within this cohort. The aim of this review was to examine common themes and data surrounding pregnancy, parenthood, and fertility within orthopaedics. Methods. A systematic review was conducted by searching Medline, Emcare, Embase, PsycINFO, OrthoSearch, and the Cochrane Library in November 2022. The Preferred Reporting Items for Systematic Reviews and Meta Analysis were adhered to. Original research papers that focused on pregnancy and/or parenthood within orthopaedic surgery were included for review. Results. Of 1,205 papers, 19 met the inclusion criteria. Our results found that orthopaedic surgeons have higher reported rates of obstetric complications, congenital abnormalities, and infertility compared to the general population. They were noted to have children at a later age and voluntarily delayed childbearing. Negative perceptions of pregnancy from fellow trainees and programme directors were identified. Conclusion. Female orthopaedic surgeons have high rates of obstetric complications and infertility. Negative perceptions surrounding pregnancy can lead to orthopaedic surgeons voluntarily delaying childbearing. There is a need for a pregnancy-positive culture shift combined with formalized guidelines and female mentorship to create a more supportive environment for pregnancy within orthopaedic surgery. Cite this article: Bone Joint J 2023;105-B(8):857–863

Literature surrounding artificial intelligence (AI)-related applications for hip and knee arthroplasty has proliferated. However, meaningful advances that fundamentally transform the practice and delivery of joint arthroplasty are yet to be realized, despite the broad range of applications as we continue to search for meaningful and appropriate use of AI. AI literature in hip and knee arthroplasty between 2018 and 2021 regarding image-based analyses, value-based care, remote patient monitoring, and augmented reality was reviewed. Concerns surrounding meaningful use and appropriate methodological approaches of AI in joint arthroplasty research are summarized. Of the 233 AI-related orthopaedics articles published, 178 (76%) constituted original research, while the rest consisted of editorials or reviews. A total of 52% of original AI-related research concerns hip and knee arthroplasty (n = 92), and a narrative review is described. Three studies were externally validated. Pitfalls surrounding present-day research include conflating vernacular (“AI/machine learning”), repackaging limited registry data, prematurely releasing internally validated prediction models, appraising model architecture instead of inputted data, withholding code, and evaluating studies using antiquated regression-based guidelines. While AI has been applied to a variety of hip and knee arthroplasty applications with limited clinical impact, the future remains promising if the question is meaningful, the methodology is rigorous and transparent, the data are rich, and the model is externally validated. Simple checkpoints for meaningful AI adoption include ensuring applications focus on: administrative support over clinical evaluation and management; necessity of the advanced model; and the novelty of the question being answered. Cite this article: Bone Joint J 2022;104-B(12):1292–1303

Aims. This systematic review and meta-analysis was conducted to compare open reduction and internal fixation (ORIF) with primary arthrodesis (PA) in the treatment of Lisfranc injuries, regarding patient-reported outcome measures (PROMs), and risk of secondary surgery. The aim was to conclusively determine the best available treatment based on the most complete and recent evidence available. Methods. A systematic search was conducted in PubMed, Cochrane Controlled Register of Trials (CENTRAL), EMBASE, CINAHL, PEDro, and SPORTDiscus. Additionally, ongoing trial registers and reference lists of included articles were screened. Risk of bias (RoB) and level of evidence were assessed using the Cochrane risk of bias tools and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. The random and fixed-effect models were used for the statistical analysis. Results. A total of 20 studies were selected for this review, of which 12 were comparative studies fit for meta-analysis, including three randomized controlled trials (RCTs). This resulted in a total analyzed population of 392 patients treated with ORIF and 249 patients treated with PA. The mean differences between the two groups in American Orthopedic Foot and Ankle Society (AOFAS), VAS, and SF-36 scores were -7.41 (95% confidence interval (CI) -13.31 to -1.51), 0.77 (95% CI -0.85 to 2.39), and -1.20 (95% CI -3.86 to 1.46), respectively. Conclusion. This is the first study to find a statistically significant difference in PROMs, as measured by the AOFAS score, in favour of PA for the treatment of Lisfranc injuries. However, this difference may not be clinically relevant, and therefore drawing a definitive conclusion requires confirmation by a large prospective high-quality RCT. Such a study should also assess cost-effectiveness, as cost considerations might be decisive in decision-making. Level of Evidence: I. Cite this article: Bone Jt Open 2021;2(10):842–849

Aims. The aim of this study was to identify the origin and development of the threshold for surgical intervention, highlight the consequences of residual displacement, and justify the importance of accurate measurement. Methods. A systematic review of three databases was performed to establish the origin and adaptations of the threshold, with papers screened and relevant citations reviewed. This search identified papers investigating functional outcome, including presence of arthritis, following injury. Orthopaedic textbooks were reviewed to ensure no earlier mention of the threshold was present. Results. Knirk and Jupiter (1986) were the first to quantify a threshold, with all their patients developing arthritis with > 2 mm displacement. Some papers have discussed using 1 mm, although 2 mm is most widely reported. Current guidance from the British Society for Surgery of the Hand and a Delphi panel support 2 mm as an appropriate value. Although this paper is still widely cited, the authors published a re-examination of the data showing methodological flaws which is not as widely reported. They claim their conclusions are still relevant today; however, radiological arthritis does not correlate with the clinical presentation. Function following injury has been shown to be equivalent to an uninjured population, with arthritis progressing slowly or not at all. Joint space narrowing has also been shown to often be benign. Conclusion. Knirk and Jupiter originated the threshold value of 2 mm. The lack of correlation between the radiological and clinical presentations warrants further modern investigation. Measurement often varies between observers, calling a threshold concept into question and showing the need for further development in this area. The principle of treatment remains restoration of normal anatomical position. Cite this article: Bone Joint J 2021;103-B(9):1457–1461

Background. Due to the overwhelming demand for trauma services, resulting from increasing emergency department attendances over the past decade, virtual fracture clinics (VFCs) have become the fashion to keep up with the demand and help comply with the BOA Standards for Trauma and Orthopaedics (BOAST) guidelines. In this article, we perform a systematic review asking, “How useful are VFCs?”, and what injuries and conditions can be treated safely and effectively, to help decrease patient face to face consultations. Our primary outcomes were patient satisfaction, clinical efficiency and cost analysis, and clinical outcomes. Methods. We performed a systematic literature search of all papers pertaining to VFCs, using the search engines PubMed, MEDLINE, and the Cochrane Database, according to the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) checklist. Searches were carried out and screened by two authors, with final study eligibility confirmed by the senior author. Results. In total, 21 records were relevant to our research question. Six orthopaedic injuries were identified as suitable for VFC review, with a further four discussed in detail. A reduction of face to face appointments of up to 50% was reported with greater compliance to BOAST guidelines (46.4%) and cost saving (up to £212,000). Conclusions. This systematic review demonstrates that the VFC model can help deliver a safe, more cost-effective, and more efficient arm of the trauma service to patients. Cite this article: Bone Joint Open 2020;1-11:683–690

The ability to edit DNA at the nucleotide level using clustered regularly interspaced short palindromic repeats (CRISPR) systems is a relatively new investigative tool that is revolutionizing the analysis of many aspects of human health and disease, including orthopaedic disease. CRISPR, adapted for mammalian cell genome editing from a bacterial defence system, has been shown to be a flexible, programmable, scalable, and easy-to-use gene editing tool. Recent improvements increase the functionality of CRISPR through the engineering of specific elements of CRISPR systems, the discovery of new, naturally occurring CRISPR molecules, and modifications that take CRISPR beyond gene editing to the regulation of gene transcription and the manipulation of RNA. Here, the basics of CRISPR genome editing will be reviewed, including a description of how it has transformed some aspects of molecular musculoskeletal research, and will conclude by speculating what the future holds for the use of CRISPR-related treatments and therapies in clinical orthopaedic practice. Cite this article: Bone Joint Res 2020;9(7):351–359

Aims. Whether to perform hybrid surgery (HS) in contrast to anterior cervical discectomy and fusion (ACDF) when treating patients with multilevel cervical disc degeneration remains a controversial subject. To resolve this we have undertaken a meta-analysis comparing the outcomes from HS with ACDF in this condition. Methods. Seven databases were searched for studies of HS and ACDF from inception of the study to 1 September 2019. Both random-effects and fixed-effects models were used to evaluate the overall effect of the C2-C7 range of motion (ROM), ROM of superior/inferior adjacent levels, adjacent segment degeneration (ASD), heterotopic ossification (HO), complications, neck disability index (NDI) score, visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, Odom’s criteria, blood loss, and operating and hospitalization time. To obtain more credible results contour-enhanced funnel plots, Egger’s and Begg’s tests, meta-regression, and sensitivity analyses were performed. Results. In total, 17 studies involving 861 patients were included in the analysis. HS was found to be superior to ACDF in maintaining C2-C7 ROM and ROM of superior/inferior adjacent levels, but HS did not reduce the incidence of associated level ASD. Also, HS did not cause a higher rate of HO than ACDF. The frequency of complications was similar between the two techniques. HS failed to achieve more favourable outcomes than ACDF using the NDI, VAS, JOA, and Odom’s scores. HS did not show any more advantages in operating or hospitalization time but did show reduction in blood loss. Conclusion. Although HS maintained cervical kinetics, it failed to reduce the incidence of ASD. This finding differs from previous reports. Moreover, patients did not show more benefits from HS with respect to symptom improvement, prevention of complications, and clinical outcomes. Cite this article: Bone Joint J 2020;102-B(8):981–996

Aims. Metabolic profiling is a top-down method of analysis looking at metabolites, which are the intermediate or end products of various cellular pathways. Our primary objective was to perform a systematic review of the published literature to identify metabolites in human synovial fluid (HSF), which have been categorized by metabolic profiling techniques. A secondary objective was to identify any metabolites that may represent potential biomarkers of orthopaedic disease processes. Methods. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using the MEDLINE, Embase, PubMed, and Cochrane databases. Studies included were case series, case control series, and cohort studies looking specifically at HSF. Results. The primary analysis, which pooled the results from 17 published studies and four meeting abstracts, identified over 200 metabolites. Seven of these studies (six published studies, one meeting abstract) had asymptomatic control groups and collectively suggested 26 putative biomarkers in osteoarthritis, inflammatory arthropathies, and trauma. These can broadly be categorized into amino acids plus related metabolites, fatty acids, ketones, and sugars. Conclusion. The role of metabolic profiling in orthopaedics is fast evolving with many metabolites already identified in a variety of pathologies. However, these results need to be interpreted with caution due to the presence of multiple confounding factors in many of the studies. Future research should include largescale epidemiological metabolic profiling studies incorporating various confounding factors with appropriate statistical analysis to account for multiple testing of the data. Cite this article:Bone Joint Res. 2020;9(3):108–119