Mid-term results of an anatomic total knee replacement design.

INTRODUCTION: A significant proportion of patients remain dissatisfied following total knee arthroplasty (TKA) surgery. Reasons for this are unclear. Contemporary implants seek to mirror innate anatomy. Such innovations are necessarily subject to scrutiny to validate their use. The Zimmer-Biomet Persona® Personalized Knee system is such an anatomic TKA. This work seeks to establish medium term survival data and patient reported outcomes for this implant. METHODS: This was a cohort study of prospectively collected data on all patients undergoing Persona TKA at our institution. Patients were managed using a standardised protocol for intra- and post-operative care. Survivorship data were collected using our National Joint Registry and corroborated with local data. Range of motion, Oxford Knee Score (OKS) and patient satisfaction were recorded at six weeks and one year post-operatively. Hip-knee-ankle radiographs were used to record pre- and post-operative alignment. RESULTS: Data were collected for 749 knees in 679 patients. Overall survivorship was 99.0% at a mean 5.35 years, with seven patients undergoing revision surgery during the study period. Significant improvements in the OKS (mean 20.7 points) and range of motion were observed (mean 104.6° at one year). 94.9% of patients were satisfied at one year. Mean correction was to a mechanical femoro-tibial angle of 0.8° varus. CONCLUSIONS: We demonstrate excellent medium term survival of the Persona TKA in this large cohort, coupled with improvements in patient reported outcomes, range of motion and patient satisfaction at one year which compare favourably to other implants.

Resuming elective orthopaedic services during the COVID-19 pandemic : our experience.

AIMS: The aim of this study was to surveil whether the standard operating procedure created for the NHS Golden Jubilee sufficiently managed COVID-19 risk to allow safe resumption of elective orthopaedic surgery. METHODS: This was a prospective study of all elective orthopaedic patients within an elective unit running a green pathway at a COVID-19 light site. Rates of preoperative and 30-day postoperative COVID-19 symptoms or infection were examined for a period of 40 weeks. The unit resumed elective orthopaedic services on 29 June 2020 at a reduced capacity for a limited number of day-case procedures with strict patient selection criteria, increasing to full service on 29 August 2020 with no patient selection criteria. RESULTS: A total of 2,373 cases were planned in the 40-week study period. Surgery was cancelled in 59 cases, six (10.2%) of which were due to having a positive preoperative COVID-19 screening test result. Of the remaining 2,314, 996 (43%) were male and 1,318 (57%) were female. The median age was 67 years (interquartile range 59.2 to 74.6). The median American Society of Anesthesiologists grade was 2. Hip and knee arthroplasties accounted for the majority of the operations (76%). Six patients tested positive for COVID-19 preoperatively (0.25%) and 39 patients were tested for COVID-19 within 30 days after discharge, with only five patients testing positive (0.22%). CONCLUSION: Through strict application of a COVID-19 green pathway, elective orthopaedic surgery could be safely delivered to a large number of patients with no selection criteria. Cite this article: Bone Jt Open 2021;2(11):951-957.

Expression of the sodium iodide symporter (NIS) in reproductive and neural tissues of teleost fish.

Iodine, an essential component of thyroid hormones, can only be obtained through the diet. The sodium iodide symporter (NIS) transports iodide across mammalian intestinal and thyroid epithelia to deliver iodide for thyroid hormone production. Using reverse transcription-polymerase chain reaction (RT-PCR) we confirmed that mRNA for a homolog of mammalian NIS is expressed in comparable locations, both sub-pharyngeal thyroid tissue and intestine, in multiple teleost fish species, supporting a conserved mechanism for intestinal-thyroid iodine transport across vertebrates. To determine when in embryogenesis NIS expression is initiated we utilized in situ hybridization (ISH) during development of zebrafish (Danio rerio) embryos. This revealed expression of nis as early as 2 days post fertilization (dpf) along the dorsal surface of the yolk sac, suggesting a function to import iodine from yolk. To evaluate the potential for maternal deposition of iodine in yolk, RT-PCR and further in situ staining of ovarian tissue in gravid female zebrafish confirmed NIS mRNA presence in the ooplasm and granulosa layer of early stage follicles. This further suggests that maternally-deposited NIS mRNA may be available for early embryogenesis. Unexpectedly, ISH in embryos revealed robust nis expression in the central nervous system throughout days 2-5 days post fertilization, with adult whole brain ISH localizing expression in the hypothalamus, cerebellum, and optic tectum. RT-PCR on whole brain tissue from five species of adult fish representing three taxonomic orders likewise revealed robust CNS expression. These unexpected locations of nis expression suggest novel, as yet undescribed reproductive and neural functions of NIS in teleost species.

A new landmark for measuring tibial component rotation after total knee arthroplasty.

BACKGROUND: Existing methods for assessment of total knee arthroplasty (TKA) component rotation on computed tomography (CT) scans are complex, especially in relation to the tibial component. Anecdotal evidence from our practice pointed towards a potential new landmark. The study aims were to check the prevalence of this landmark, define tibial component rotation in relation to it and demonstrate its reliability. METHODS: Two hundred and eleven CTs undertaken following TKA were reviewed for presence of the landmark. A protocol to measure tibial component rotation in relation to this landmark was developed and the rotation measured using this method and Berger's protocol. Thirty one of the 211 CT scans were measured twice by two observers. Reliability was calculated using the Intraclass Correlation Coefficient (ICC). RESULTS: The new landmark of a flat area on the lateral cortex of the tibia inferior to the tibial component was identified on all scans. Median tibial component rotation measured using our protocol was 0.0°â€¯±â€¯5.4° and -9.2°â€¯±â€¯5.5° using Berger's protocol. Intra-observer reliability with the new method was excellent (ICCs of 0.899 and 0.871) and inter-observer reliability was good (ICCs of 0.734 and 0.836). CONCLUSIONS: The new landmark had a very high prevalence and could be used to define tibial component rotation. This measurement of tibial component rotation had acceptable reliability. This landmark has potential for use in the radiological assessment of tibial component rotation following TKA. Further work is required to determine its relationship to anatomical structures and symptoms of tibial component mal-rotation.