Does arthroscopic or open washout in native knee septic arthritis result in superior post-operative function? A systematic review and meta-analysis of randomised controlled trials and observational studies.

AIMS: Septic arthritis (SA) of the native knee joint is associated with significant morbidity. This review compared post-operative functional outcomes (patient-reported outcome measures (PROMs) and range of movement (ROM)) following arthroscopic washout (AW) and open washout (OW) amongst adult patients with SA of the native knee. The need for further operative intervention was also considered. METHODS: Electronic databases of PubMed, MEDLINE, Embase, Cochrane, Web of Science and Scopus were searched between 16 February 2023 and 18 March 2023. Randomised controlled trials (RCTs) and comparative observational analytic studies comparing function (reflected in PROMs or ROM) at latest follow-up following AW and OW were included. A narrative summary was provided concerning post-operative PROMs. Pooled estimates for mean ROM and re-operation rates were conducted using the random-effects model. The risk of bias was assessed using the Cochrane risk-of-bias assessment tool-2 for RCTs and the Risk of Bias in Non-Randomized Studies of Interventions tool for observational analytic studies. RESULTS: Of 2580 retrieved citations, 7 articles (1 RCT and 6 cohort studies) met the inclusion criteria. Of these, five had some concerns/moderate risk of bias, and two had serious risk. There was a slight tendency for superior mean PROMs following AW compared with OW, but due to small effect sizes, this was unlikely clinically relevant. Additionally, the use of four different PROMs scales made direct comparisons impossible. AW was associated with superior ROM (mean difference 20.18° (95% CI 14.35, 26.02; p < 0.00001)), whilst there was a tendency for lower re-operation requirements following AW (OR 0.64, 95% CI 0.26, 1.57, p = 0.44). CONCLUSIONS: AW was associated with equivalent to superior post-operative function and lower requirement for further intervention compared with OW. Results need to be interpreted cautiously, taking into consideration the methodological and clinical heterogeneity of the included studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2022, CRD42022364062.

Robotic-Assisted Patellofemoral Replacement-Correlation of Preoperative Planning with Intraoperative Implant Position and Early Clinical Experience: A Minimum 2-Year Follow-up.

Patello-femoral arthroplasty (PFA) is successful in a selected group of patients and yields a good functional outcome. Robotic-assisted knee arthroplasty has been shown to provide better implant positioning and alignment. We aim to report our early outcomes and to compare Mako's (Robotic Arm Interactive Orthopaedic System [RIO]) preoperative implant planning position to our intraoperative PFA implant position. Data for this study was prospectively collected for 23 (two bilateral) patients who underwent robotic-assisted PFA between April 2017 and May 2018. All preoperative implant position planning and postoperative actual implant position were recorded. Presence of trochlear dysplasia and functional outcome scores were also collected. There were 17 (two bilateral) female and 6 male patients with a mean age of 66.5 (range: 41-89) years. The mean follow-up period was 30 (range: 24-37) months. Eighteen knees (72%) had evidence of trochlear dysplasia. The anterior trochlear line was on average, 7.71 (range: 3.3-11.3) degrees, internally rotated to the surgical transepicondylar axis and on average 2.9 (range: 0.2-6.5) degrees internally rotated to the posterior condylar line. The preoperative planning range was 4-degree internal to 4-degree external rotation, 4-degree varus to 6-degree valgus, and 7-degree flexion to 3-degree extension. The average difference between preoperative planning and intraoperative implant position was 0.43 degrees for rotation (r = 0.93), 0.99 degrees for varus/valgus (r = 0.29), 1.26 degrees for flexion/extension (r = 0.83), and 0.34 mm for proudness (r = 0.80). Six patients (24%) had a different size component from their preoperative plan (r = 0.98). The mean preoperative Oxford Knee Score (OKS) was 16 and the mean postoperative OKS was 42. No patient had implant-related revision surgery or any radiological evidence of implant loosening at final follow-up. Our early results of robotic PFA are promising. Preoperative Mako planning correlates closely with intraoperative implant positioning. Longer follow-up is needed to assess long-term patient outcomes and implant survivorship.

Prosthetic joint infection of the knee - arthroscopic biopsy identifies more and different organisms than aspiration alone.

BACKGROUND: Prosthetic joint infection (PJI) causes significant morbidity and mortality following knee replacement surgery. Identifying causative organisms and antibiotic sensitivities is critical in increasing the chance of infection eradication. This study investigated whether biopsy alone was superior to aspiration alone for serological diagnosis in PJI following knee replacement. Secondly, we investigated whether biopsy identifies the same or new/different microbiological flora as aspiration. METHODS: Since December 2014, the Exeter Knee Reconstruction Unit (EKRU) has prospectively collated data regarding all PJIs referred from our local/regional network which have been reviewed via our Multi-Disciplinary Team (MDT). We identified and included consecutive patients from this MDT from Dec.2014-Mar.2020 and analysed their electronic records. Statistical analysis was performed using Stata. RESULTS: 65/100 patients studied had both pre-operative aspiration and biopsy. 31/65 (48%) had positive aspiration and biopsies. No aspirate samples were positive with corresponding biopsies negative. In 19/65 (29%) of infection positive patients, biopsy identified new (7) or additional (12) organisms not identified by aspiration. Aspiration had a sensitivity of 70%, specificity of 88%, positive predictive value of 90.3% and negative predictive value of 64.7%. Biopsy had a sensitivity of 97.5%, specificity of 88%, positive predictive value of 92.9% and negative predictive value of 95.7%. CONCLUSION: In 29% of confirmed PJI cases, arthroscopic biopsy identified either additional organisms in a polymicrobial PJI when compared to aspiration, or new positive results when aspiration alone was negative. This study demonstrates the benefits of arthroscopic biopsy for serological diagnosis in cases of knee PJI and aids treatment planning.

Metaphyseal Sleeves in Revision Total Knee Arthroplasty Provide Reliable Fixation and Excellent Medium to Long-Term Implant Survivorship.

BACKGROUND: Addressing bone loss and securing implant fixation can be challenging in revision total knee arthroplasty (TKA). We present the results of a large series of revision TKAs using a metaphyseal sleeve. METHODS: We retrospectively analyzed 319 revision TKAs with the use of a metaphyseal sleeve that had been followed up for at least 2 years, using a prospectively collected database. The mean follow-up was 91 months, and 73 patients were followed up for more than 10 years. RESULTS: Implant survivorship was 99.1% at 3 years, 98.7% at 5 years, and 97.8% at 10 years. No metaphyseal sleeve was revised for aseptic loosening. Final radiographic review showed that there were radiolucent lines present in 2.8% of tibial sleeves and 2.7% of femoral sleeves; none of these had progressed and none were revised. About 3.7% of tibial sleeves subsided more than 1 mm compared with the immediate postoperative X-ray but all stabilized and none were revised. CONCLUSION: Use of a metaphyseal sleeve in revision TKA is associated with excellent survivorship and radiographic outcome in the medium to long term.

Failure to Return to Preinjury Activity Level after Hamstring Anterior Cruciate Ligament Reconstruction: Factors Involved and Considerations in Goal Setting.

BACKGROUND: Recent interest in the return to sports, following anterior cruciate ligament reconstruction, has focused on the influence of psychological factors. However, many factors contribute to this endpoint. This study aimed to investigate the ability of nonprofessional athletes to return alongside the reasons for failure. MATERIALS AND METHODS: We retrospectively studied 101 postreconstruction patients with followup in excess of 12 months. All patients underwent hamstring autograft anterior cruciate reconstruction. The Cincinnati Sports Activity Scale was used to define activity level preinjury, postinjury, and postreconstruction. Structured questionnaires were used to identify factors in those who did not return to the same level. RESULTS: Seventy percent of patients returned to their preinjury activity score. Of the 30% of patients who failed, age, reconstruction type, and associated pathology were unrelated. However, reconstruction within 6 months of injury resulted in increased return to preinjury score (P < 0.05). Failure was associated with continued knee symptoms (57%), lifestyle changes (27%), anxiety (27%), fear (23%), and other musculoskeletal problems (10%). Considerable interplay was found between these factors. Failure to return was associated with increased further surgery, but this was successful in only one-third of patients. CONCLUSION: Psychological factors are important (and may require targeted input), but return-to-sport is multifactorial. Ongoing symptoms may prompt further surgery, but this is frequently unsuccessful in achieving return. Patient-specific goals should be sought and revisited throughout the rehabilitation program. Acknowledging psychological barriers, in those aiming to return to the same level, may help achieve this goal. In other patients, success may be return to a desired lower level. Understanding the patient's expectations is important in goal setting.

Plasma Viscosity Has a Role in the Diagnosis of Prosthetic Joint Infection After Total Knee Arthroplasty.

BACKGROUND: The diagnosis of prosthetic joint infection (PJI) is challenging because no single test has consistently demonstrated an adequate discriminative potential. The combination of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) with adequate thresholds is well established. This study sought to investigate the role of plasma viscosity (PV) in the diagnosis of PJI following painful total knee arthroplasty. METHODS: The medical notes, and hematological and microbiology results of 310 patients who underwent revision for a painful total knee arthroplasty were evaluated. Infection was confirmed using Musculoskeletal Infection Society criteria in 102 patients (32.9%), whereas 208 patients (67.1%) were classified as noninfected. Serum investigations including ESR, CRP, and PV were analyzed using receiver observer curves and optimal cutoff points identified. RESULTS: There was a strong correlation between PV and both ESR and CRP. The area under curve was 0.814 for PV and 0.812 for ESR. Statistical analysis showed noninferiority of PV as compared to ESR in diagnosing PJI. A PV value of ≥ 1.81 mPa.s. had the best efficiency of 82.1%. Combining a CRP ≥ 13.5 mg/L with a PV ≥ 1.81 mPa.s. in a serial test approach yielded the highest specificity of 97.9% and positive likelihood ratio of 22.8. Sensitivity was 47.9% and a negative likelihood ratio of 0.53. CONCLUSION: PV is noninferior to ESR in diagnosing PJI. Its use is justified in clinical practice. It is cheaper, quicker, more efficient, and not influenced by hematocrit levels or medication. In this cohort, a PV value ≥ 1.81 mPa.s. would be an adequate cutoff to diagnose PJI in combination with CRP ≥ 13.5 mg/L.

Complex Regional Pain Syndrome after Total Knee Arthroplasty is Rare and Misdiagnosis Potentially Hazardous-Prospective Study of the New Diagnostic Criteria in 100 Patients with No Cases Identified.

Previous studies suggest that complex regional pain syndrome (CRPS) occurs in up to 21% of patients following total knee arthroplasty (TKA). However, this diagnosis has a substantial impact on the patient's management if it is incorrect. We aimed to identify cases, using updated internationally accepted criteria, while investigating potential causes of misdiagnosis.We prospectively studied a consecutive series of 100 primary TKA patients. Each patient was assessed 6-week post-TKA. Pain levels were recorded with the presence of symptoms and signs of CRPS (Budapest Diagnostic Criteria) assessed in those with excessive pain. An alternative diagnosis was sought, in these patients, including the presence of neuropathic pain.We found no cases of CRPS (no patients had symptoms or signs in greater than two of four subgroups). Seventeen patients had excessive pain levels (nine had an alternative diagnosis explaining this). The commonest signs were sensory and sudomotor, whereas motor/trophic changes were not seen. Using a previous definition (Orlando Criteria), eight patients may have been diagnosed with CRPS. Over half of the patients with unexplained excessive pain had evidence of neuropathic pain.CRPS is a rare diagnosis following TKA using modern criteria. Isolated signs and symptoms may lead to the overdiagnosis of CRPS in the presence of unexplained pain following TKA. New diagnostic criteria, with strict definitions and treatment algorithms, are now accepted. Delays in managing more common causes (such as neuropathic pain) may negatively affect the patient's outcome.

Comparative analysis of maize (Zea mays) crop performance: natural variation, incremental improvements and economic impacts.

Grain yield from maize hybrids continues to improve through advances in breeding and biotechnology. Despite genetic improvements to hybrid maize, grain yield from distinct maize hybrids is expected to vary across growing locations due to numerous environmental factors. In this study, we examine across-location variation in grain yield among maize hybrids in three case studies. The three case studies examine hybrid improvement through breeding, introduction of an insect protection trait or introduction of a transcription factor trait associated with increased yield. In all cases, grain yield from each hybrid population had a Gaussian distribution. Across-location distributions of grain yield from each hybrid partially overlapped. The hybrid with a higher mean grain yield typically outperformed its comparator at most, but not all, of the growing locations (a 'win rate'). These results suggest that a broad set of environmental factors similarly impacts grain yields from both conventional- and biotechnology-derived maize hybrids and that grain yields among two or more hybrids should be compared with consideration given to both mean yield performance and the frequency of locations at which each hybrid 'wins' against its comparators. From an economic standpoint, growers recognize the value of genetically improved maize hybrids that outperform comparators in the majority of locations. Grower adoption of improved maize hybrids drives increases in average U.S. maize grain yields and contributes significant value to the economy.

Comparative analysis of LEA-like 11-24 gene expression and regulation in related plant species within the Linderniaceae that differ in desiccation tolerance.

The resurrection plant Craterostigma plantagineum is able to withstand desiccation of its vegetative tissues and is found in areas with variable water availability. The closely related species Lindernia brevidens and Lindernia subracemosa are both endemic to montane rainforests of coastal Africa, but remarkably L. brevidens is tolerant to desiccation. We studied the regulation of the desiccation-related LEA-like 11-24 gene at multiple levels in closely related species in order to investigate the conservation of mechanisms involved in desiccation tolerance. The dehydration-responsive transcription of the LEA-like 11-24 gene is differentially regulated in these plants. Comparison of the LEA-like 11-24 core promoter regions revealed that promoters have different activities, but some functional cis-acting elements are conserved between species. Upon dehydration, LEA-like 11-24 proteins are phosphorylated at different levels and phosphorylation sites are not conserved among the three LEA-like 11-24 proteins. Differences in the regulation of the LEA-like 11-24 gene in the studied plant species appear to be the result of mutations that occurred during evolution. We postulate that L. brevidens will eventually lose the ability to survive vegetative desiccation, given that this trait appears not to be essential for survival.

Lindernia brevidens: a novel desiccation-tolerant vascular plant, endemic to ancient tropical rainforests.

A particular adaptation to survival under limited water availability has been realized in the desiccation-tolerant resurrection plants, which tend to grow in a habitat with seasonal rainfall and long dry periods. One of the best-studied examples is Craterostigma plantagineum. Here we report an unexpected finding: Lindernia brevidens, a close relative of C. plantagineum, exhibits desiccation tolerance, even though it is endemic to the montane rainforests of Tanzania and Kenya, where it never experiences seasonal dry periods. L. brevidens has been found exclusively in two fragments of the ancient Eastern Arc Mountains, which were protected from the devastating Pleistocene droughts by the stable Indian Ocean temperature. Analysis of the microhabitat reveals that L. brevidens is found in the same habitat as hygrophilous plant species, which further indicates that the plant never dries out completely. The objective of this investigation was to address whether C. plantagineum and L. brevidens have desiccation-related pathways in common, or whether L. brevidens has acquired novel pathways. A third, closely related, desiccation-sensitive species, Lindernia subracemosa, has been included for comparison. Mechanisms that confer cellular protection during extreme water loss are well conserved between C. plantagineum and L. brevidens, including the interconversion of 2-octulose to sucrose within the two desiccation-tolerant species. Furthermore, transcriptional control regions of desiccation-related genes belonging to the late embryogenesis abundant (LEA) protein family are also highly conserved. We propose that L. brevidens is a neoendemic species that has retained desiccation tolerance through genome stability, despite tolerance being superfluous to environmental conditions.

The role of small RNAs in abiotic stress.

It was recently discovered that plants respond to environmental stress not only with a specific gene expression programme at the mRNA and protein level but also small RNAs as response modulators play an important role. The small RNAs lead to cleavage or translational inhibition of mRNAs via complementary target sites. Different examples are described where small RNAs have been shown to be involved in stress responses. A link between hormonal action and small RNA activities has frequently been observed thus coupling exogenous factors with endogenous transmitters. Using the CDT-1 gene from the desiccation tolerant plant Craterostigma plantagineum as an example, it is discussed that generation of novel small RNAs could be an evolutionary pathway in plants to adapt to extreme environments.

Transcriptome analysis reveals season-specific rbcS gene expression profiles in diploid perennial ryegrass (Lolium perenne L.).

Perennial ryegrass (Lolium perenne L.) is a major grass species used for forage and turf throughout the world, and gains by conventional breeding have reached a plateau. Perennial ryegrass is an outcrossing, self-incompatible diploid (2n = 2x = 14) with a relatively large genome (4067 Mbp/diploid genome; Evans, G.M., Rees, H., Snell, C.L. and Sun, S. (1972) The relation between nuclear DNA amount and the duration of the mitotic cycle. Chrom. Today, 3, 24-31). Using tissues sourced from active pastures during the peak of the autumn, winter, spring and summer seasons, we analysed the ryegrass transcriptome employing a Serial Analysis of Gene Expression (SAGE) protocol, with the dual goals of understanding the seasonal changes in perennial ryegrass gene expression and enhancing our ability to select genes for genetic manipulation. A total of 159,002 14-mer SAGE tags was sequenced and mapped to the perennial ryegrass DNA database, comprising methyl-filtered (GeneThresher) and expressed sequence tag (EST) sequences. The analysis of 14,559 unique SAGE tags, which were present more than once in our SAGE library, revealed 964, 1331, 346 and 131 exclusive transcripts to autumn, winter, spring and summer, respectively. Intriguingly, our analysis of the SAGE tags revealed season-specific expression profiles for the small subunit of ribulose-1,5-bisphosphate carboxylase (Rubisco), LprbcS. The transcript level for LprbcS was highest in spring, and then decreased gradually between summer and winter. Five different copies of LprbcS were revealed in ryegrass, with one possibly producing splice variant transcripts. Two highly expressed LprbcS genes were reported, one of which was not active in autumn. Another LprbcS gene showed an inverse expression profile to the autumn inactive LprbcS in a manner to compensate the expression level.

A novel abscisic acid- and dehydration-responsive gene family from the resurrection plant Craterostigma plantagineum encodes a plastid-targeted protein with DNA-binding activity.

In the desiccation-tolerant resurrection plant Craterostigma plantagineum Hochst. the chloroplasts undergo major ultrastructural changes during dehydration, which are reversible upon rehydration. Such alterations argue the need for efficient protective/stabilising mechanisms to exist. Here we describe a novel gene family that is rapidly and transiently expressed in response to both dehydration and exogenously applied abscisic acid, mostly in the chloroplast-rich palisade layer on the adaxial side of the leaf. Analysis of the putative coding region suggests that the resulting protein is plastid-targeted. This was confirmed using a chimeric green fluorescent protein (GFP) reporter construct in transgenic tobacco plants - hence the gene family is termed Plastid Targeted Protein ( CpPTP). Fluorescence microscopy also revealed that CpPTP was localised in structures similar to proplastid nucleoids in transgenic tobacco ( Nicotiana tabacum L.) BY-2 cells. The ability of CpPTP to interact with DNA was demonstrated through a DNaseI protection assay. A structure-prediction programme suggests that the mature CpPTP is composed almost entirely of a pattern of hydrophobic and hydrophilic residues that form heptad repeats, which are the hallmarks of a coiled-coil domain. Given the localisation and DNA-binding property of the protein, we propose that CpPTP plays a role during the early stages of dehydration-induced chloroplast remodelling.