Metal allergy in primary and revision total knee arthroplasty : a scoping review and evidence-based practical approach.

AIMS: Metal allergy in knee arthroplasty patients is a controversial topic. We aimed to conduct a scoping review to clarify the management of metal allergy in primary and revision total knee arthroplasty (TKA). METHODS: Studies were identified by searching electronic databases: Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Embase, from their inception to November 2020, for studies evaluating TKA patients with metal hypersensitivity/allergy. All studies reporting on diagnosing or managing metal hypersensitivity in TKA were included. Data were extracted and summarized based on study design, study population, interventions and outcomes. A practical guide is then formulated based on the available evidence. RESULTS: We included 38 heterogeneous studies (two randomized controlled trials, six comparative studies, 19 case series, and 11 case reports). The evidence indicates that metal hypersensitivity is a rare complication with some histopathological features leading to pain and dissatisfaction with no reliable screening tests preoperatively. Hypoallergenic implants are viable alternatives for patients with self-reported/confirmed metal hypersensitivity if declared preoperatively; however, concerns remain over their long-term outcomes with ceramic implants outperforming titanium nitride-coated implants and informed consent is paramount. For patients presenting with painful TKA, metal hypersensitivity is a diagnosis of exclusion where patch skin testing, lymphocyte transformation test, and synovial biopsies are useful adjuncts before revision surgery is undertaken to hypoallergenic implants with shared decision-making and informed consent. CONCLUSION: Using the limited available evidence in the literature, we provide a practical approach to metal hypersensitivity in TKA patients. Future national/registry-based studies are needed to identify the scale of metal hypersensitivity, agreed diagnostic criteria, and management strategies. Cite this article: Bone Jt Open 2021;2(10):785-795.

Successful outcomes following neurorehabilitation in military traumatic brain injury patients in the United Kingdom.

BACKGROUND: The Defence Medical Rehabilitation Centre Headley Court is the UK military rehabilitation unit. A pilot study identified the Mayo-Portland Adaptability Inventory-4 (MPAI-4) as the most appropriate rehabilitation outcome measure in young military patients with acquired brain injury. METHODS: MPAI-4 scores were prospectively recorded for patients on admission and discharge. At 4 months, independent living and employment status were recorded. Inclusion criteria were all new admissions with traumatic brain injury (TBI). Before injury, all patients were fully employed and lived independently. RESULTS: In a 3-year period from April 2011, there were 91 TBI patients with complete admission-discharge episodes: by US Department of Defense criteria, 21 were mild, 35 were moderate, and 35 were severe. There was a significant positive relationship between TBI severity and MPAI-4 score on admission (χ = 12.77, df = 2, p = 0.0017).Median age was 27 years, and median duration of admission was 63 days. Employment and independent living status were available for 79 patients at 4 months. Seventy-three patients (92%) were in community-based employment, with 64 (81%) employed in a competitive or transitional work; 6 (8%) were unemployed or in sheltered work. Sixty-nine (87%) were living independently, and 10 (13%) were living with support in their own home, with no one requiring institutional care.Complete MPAI-4 scores were available for 79 patients. There were statistically and clinically significant improvements in MPAI-4 scores between admission and discharge for the overall group: median admission T score was 40.0 (95% confidence interval, 36.0-42.0) and on discharge was 31.0 (95% confidence interval, 27.0-36.0), a nine-point change (Z = 6.53, p < 0.0001). These improvements with rehabilitation were sustained when patients were subdivided by TBI severity or MPAI-4 limitations. CONCLUSION: This study demonstrates significant functional improvements in military TBI patients following intensive inpatient multidisciplinary rehabilitation, which includes substantial vocational rehabilitation. At 4 months, 92% were employed, and 87% were living independently. LEVEL OF EVIDENCE: Therapeutic study, level V; prognostic/epidemiologic study, level IV.

Surface Modified Biodegradable Electrospun Membranes as a Carrier for Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells.

Human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells are currently undergoing clinical trials to treat retinal degenerative diseases. Transplantation of hESC-RPE cells in conjuction with a supportive biomaterial carrier holds great potential as a future treatment for retinal degeneration. However, there has been no such biodegradable material that could support the growth and maturation of hESC-RPE cells so far. The primary aim of this work was to create a thin porous poly (L-lactide-co-caprolactone) (PLCL) membrane that could promote attachment, proliferation, and maturation of the hESC-RPE cells in serum-free culture conditions. The PLCL membranes were modified by atmospheric pressure plasma processing and coated with collagen IV to enhance cell growth and maturation. Permeability of the membranes was analyzed with an Ussing chamber system. Analysis with scanning electron microscopy, contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy demonstrated that plasma surface treatment augments the surface properties of the membrane, which enhances the binding and conformation of the protein. Cell proliferation assays, reverse transcription-polymerase chain reaction, indirect immunofluoresence staining, trans-epithelial electrical resistance measurements, and in vitro phagocytosis assay clearly demonstrated that the plasma treated PLCL membranes supported the adherence, proliferation, maturation and functionality of hESC-RPE cells in serum-free culture conditions. Here, we report for the first time, how PLCL membranes can be modified with atmospheric pressure plasma processing to enable the formation of a functional hESC-RPE monolayer on a porous biodegradable substrate, which have a potential as a tissue-engineered construct for regenerative retinal repair applications.