The completeness of national hip and knee replacement registers.

Background And Purpose:  National joint replacement registries were developed for prospective monitoring of outcomes and post-market surveillance of implants. Increasingly registry data informs practice. However, analysis of a registry can only be as good as the data it captures on the population of interest.

An analysis of the effect of the COVID-19-induced joint replacement deficit in England, Wales, and Northern Ireland suggests recovery will be protracted.

Aims: The COVID-19 pandemic has disrupted the provision of arthroplasty services in England, Wales, and Northern Ireland. This study aimed to quantify the backlog, analyze national trends, and predict time to recovery.

Methods: We performed an analysis of the mandatory prospective national registry of all independent and publicly funded hip, knee, shoulder, elbow, and ankle replacements in England, Wales, and Northern Ireland between January 2019 and December 2022 inclusive, totalling 729,642 operations.

Implementing large-scale data quality validation in a national arthroplasty registry to improve compliance : the National Joint Registry data quality audit programme.

Data of high quality are critical for the meaningful interpretation of registry information. The National Joint Registry (NJR) was established in 2002 as the result of an unexpectedly high failure rate of a cemented total hip arthroplasty. The NJR began data collection in 2003.

A field ionizer for photodetachment studies of negative ions.

In this paper, we present an apparatus for studies into the photodetachment process of atomic negative ions. State-selective detection of the residual atom following the initial photodetachment step is achieved by combining resonant laser excitation of the photo-detached atom with electric field ionization. The resonance ionization technique in combination with a co-linear ion-laser beam geometry gives an experimental apparatus that has both high selectivity and sensitivity.

The relevance of ice crystal formation for the cryopreservation of tissues and organs.

This paper discusses the role of ice crystal formation in causing or contributing to the difficulties that have been encountered in attempts to develop effective methods for the cryopreservation of some tissues and all organs. It is shown that extracellular ice can be severely damaging but also that cells in situ in tissues can behave quite differently from similar cells in a suspension with respect to intracellular freezing. It is concluded that techniques that avoid the formation of ice altogether are most likely to yield effective methods for the cryopreservation of recalcitrant tissues and vascularised organs.

Cryopreservation of articular cartilage. Part 3: The liquidus-tracking method.

Although it is relatively straightforward to cryopreserve living isolated chondrocytes, at the present time there is no satisfactory method to preserve surgical grafts between the time of procurement or manufacture and actual use. In earlier papers we have established that the cryoprotectants dimethyl sulphoxide or propylene glycol do penetrate into this tissue very rapidly. Chondrocytes are not unusually susceptible to osmotic stress; in fact they appear to be particularly resistant.

Cryopreservation of the common carotid artery of the rabbit: Optimization of dimethyl sulfoxide concentration and cooling rate.

This paper describes the continuation of studies that demonstrated the suitability of CP-Tes solution as a medium for the introduction and removal of dimethyl sulfoxide in rabbit common carotid arteries and established the kinetics of cryoprotectant permeation in that tissue. In this paper we report the tolerance of rabbit common carotid artery to dimethyl sulfoxide, in concentrations up to 30% (w/w), using a technique of exposure that was designed to control osmotic stress. The maximum concentration achieved without damage was 15% (w/w).

EVALUATION OF DMSO TRANSPORT IN HUMAN ARTICULAR CARTILAGE: VEHICLE SOLUTIONS AND EFFECTS ON CELL FUNCTION.

Osteochondral allografting techniques are limited by the availability of suitable donor tissue; there is an urgent need for effective cryopreservation. A fundamental requirement is the need to establish initial conditions of exposure to cryoprotectant that the chondrocytes will tolerate and that load the tissue with an adequate concentration of cryoprotectant. Three vehicle solutions to transport DMSO into the tissue were studied.

A liquidus tracking approach to the cryopreservation of human cartilage allografts.

In the "liquidus tracking" (LT) approach to cryopreservation both the temperature and the concentration of cryoprotectant (CPA) are controlled such that solution composition "tracks" the liquidus (melting point) line for that system. Ice crystal formation is prevented but the tissue is not exposed to CPA concentrations exceeding those experienced by cells during conventional cryopreservation. This approach is particularly appropriate for articular cartilage because chondrocytes in situ are exquisitely susceptible to damage by the crystallisation of ice.

Principles of cryopreservation.

Cryopreservation is the use of very low temperatures to preserve structurally intact living cells and tissues. Unprotected freezing is normally lethal and this chapter seeks to analyze some of the mechanisms involved and to show how cooling can be used to produce stable conditions that preserve life. The biological effects of cooling are dominated by the freezing of water, which results in the concentration of the solutes that are dissolved in the remaining liquid phase.

A standardised protocol for the validation of banking methodologies for arterial allografts.

The objective of this study was to design and test a protocol for the validation of banking methodologies for arterial allografts. A series of in vitro biomechanical and biological assessments were derived, and applied to paired fresh and banked femoral arteries. The ultimate tensile stress and strain, suture pullout stress and strain, expansion/rupture under hydrostatic pressure, histological structure and biocompatibility properties of disinfected and cryopreserved femoral arteries were compared to those of fresh controls.

Key components of the mode of action for hemangiosarcoma induction in pregabalin-treated mice: evidence of increased bicarbonate, dysregulated erythropoiesis, macrophage activation, and increased angiogenic growth factors in mice but not in rats.

In carcinogenicity studies, pregabalin increased hemangiosarcoma incidence in mice but not in rats. Investigative studies, ranging in length from 24 h to 12 months, were conducted in mice (1000 or 5000 mg/kg) and rats (900 mg/kg) to evaluate a potential mode-of-action scheme for tumor formation. Three areas were evaluated: (1) hematopoiesis (because endothelial and hematopoietic cells arise from the same precursor and hemangiosarcomas are primarily located in mouse hematopoietic tissues), (2) angiogenic growth factors (because increased angiogenic growth factors may stimulate vascular tumors), and (3) pulmonary/blood gas parameters (because hypoxia is a known driver for endothelial cell proliferation).

Mode of action associated with development of hemangiosarcoma in mice given pregabalin and assessment of human relevance.

Pregabalin increased the incidence of hemangiosarcomas in carcinogenicity studies of 2-year mice but was not tumorigenic in rats. Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH.

Hemangiosarcoma in mice administered pregabalin: analysis of genotoxicity, tumor incidence, and tumor genetics.

Pregabalin, (S)-3-(aminomethyl)-5-methylhexanoic acid, binds with high affinity to the α(2)δ subunit of voltage-gated calcium channels and exerts analgesic, anxiolytic, and antiseizure activities. Two-year carcinogenicity studies were completed in B6C3F1 and CD-1 mice and two separate studies in Wistar rats. Doses in mice were 200, 1000, and 5000 mg/kg/day, with systemic exposures (AUC(0-24 h)) up to 31 times the mean exposure in humans, given the maximum recommended clinical dose.

Threshold photodetachment in a repulsive potential.

We report on the first experimental observation of a new threshold behavior observed in the 5(2)G partial channel in photodetachment of K(-). It arises from the repulsive polarization interaction between the detached electron and the residual K(5(2)G) atom, which has a large negative dipole polarizability. In order to account for the observation in the K(5(2)G) channel, we have developed a semiclassical model that predicts an exponential energy dependence for the cross section.

Idiopathic acquired supraglottic web: a case report.

We report a case of an idiopathic acquired supraglottic web in an 83-year-old man. The web was managed with a combination of dilation and unilateral CO(2) laser excision. Subsequent to removal, the web recurred three times; it was removed in the same fashion twice and left alone once.

Trochanteric fixation using a third-generation cable device--minimum follow-up of 3 years.

Third-generation trochanteric fixation cable systems are designed to overcome implant breakage, nonunion, and bony escape. The study prospectively assessed the functional and radiologic outcomes using such an implant. Forty-seven trochanteric fixations in 46 patients were performed over 4 years at 2 institutions using the Accord Cable Plate system (Smith and Nephew, Memphis, Tenn).