Minimum 5 Year Clinical Outcomes And Survivorship For A Single Revision Total Knee Arthroplasty System Using Hybrid Fixation and Press-Fit Stems

BACKGROUND

Hybrid fixation, utilizing diaphyseal press-fit stems and cement fixation in the tibial and femoral metaphyseal areas, has long been a strategy for revision total knee arthroplasty (rTKA). The purpose of this study was to evaluate the clinical outcomes and survivorships of hybrid fixation using a single rTKA revision system with a minimum of 5 years follow-up.

METHODS

We reviewed our prospectively collected database to identify 281 patients who underwent rTKA using a single revision system with hybrid fixation and press-fit stems between July 2006 and August 2016. We reviewed the clinical outcome scores, including the Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, and Veterans RAND 12 Item Health Survey (VR-12). We also evaluated the 5- and 10-year survivorships and the indications for re-operations.

RESULTS

The cohort had a mean age of 70 years (range, x to y) and a mean body mass index of 33.4 (range, x to y). The mean time from rTKA surgery was 11.1 years (range, x to y). Above in yellow goes into ethods section Paired t-test analyses showed significant improvements from pre-operative versus post-operative clinical outcome scores (P<0.001) for KSS, WOMAC and VR-12 Physical component. Prosthetic joint infections after index rTKA was the most common failure mode with 29 patients requiring re-operations. Re-revision due to aseptic loosening was uncommon (6 patients) with a cumulative survival rate of 95.2% at 5 years and 94.2% at 10 years.

CONCLUSION

The use of this single rTKA system utilizing press fit stems combined with hybrid fixation provided significant improvements in the clinical outcomes and excellent survivorships at 5 and 10 years.

Hepatitis C: Current Controversies and Future Potential in Solid Organ Transplantation

PURPOSE OF REVIEW

To highlight the changing landscape of hepatitis C virus (HCV) infection in the context of organ transplantation. This focuses on areas of controversy and future potential in the era of highly effective direct-acting antiviral (DAA) agents.

RECENT FINDINGS

Since the advent of safe and highly effective DAA therapy, HCV infection is now curable in virtually all cases, including organ transplant recipients. Excellent drug tolerability and safety combined with high cure rates across all organ groups means that HCV is no longer a barrier to transplantation or its outcomes. Mounting data demonstrate the safety of using organs from HCV-infected donors with subsequent treatment of HCV in the recipient and a potential to expand the donor pool. Historical data demonstrating inferior survival in transplant recipients with HCV is of limited relevance in the DAA era. Virtually all transplant recipients with HCV infection can be cured, while early data also suggest excellent outcomes in recipients of organs from HCV viremic donors. The optimal timing of HCV therapy in relation to transplantation and the optimal use of organs from HCV viremic donors remain areas of controversy and ongoing research efforts.

Highly cross-linked polyethylene decreases the rate of revision of total hip arthroplasty compared with conventional polyethylene at 13 years' follow-up

AIMS

The purpose of this study was to compare the long-term results of primary total hip arthroplasty (THA) in young patients using either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene liner in terms of functional outcome, incidence of osteolysis, radiological wear and rate of revision.

METHODS

We included all patients between the ages of 45 and 65 years who, between January 2000 and December 2001, had undergone a primary THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular liner and a 28 mm cobalt-chrome femoral head. From a total of 160 patients, 158 (177 hips) were available for review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m(2) (19 to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65); BMI: 30 kg/m(2) (18 to 51); 13.1 years (5.7 to 14.4).

RESULTS

The mean Harris hip score (HHS) at final follow-up was 89.3 for the CPE group and 90.9 for the HXLPE group (p = 0.078). Osteolysis was present around 15 acetabular (17%) and 16 femoral (18%) components in the CPE hips compared with none (0%) in the HXLPE hips. The mean radiological linear wear of the CPE liners was 0.11 mm/year compared with 0.035 mm/year for the HXLPE liners (p = 0.006). The cumulative implant survival, with revision for polyethylene wear as the endpoint, was 86% (95% confidence interval 78 to 94) in the CPE group and 100% in the HXLPE group at 13 years (numbers at risk at 13 years - CPE: 65, XLPE: 61).

DISCUSSION

This study shows that HXLPE liners are associated with significantly less osteolysis and a lower rate of revision THA than CPE liners at long-term follow-up.

TAKE HOME MESSAGE

The findings of this study highlight the clinical benefits of using HXLPE liners in THA and support the routine use of the material in order to improve implant longevity and to decrease the number of patients needing revision for aseptic osteolysis.

Knee manipulation under anaesthetic following total knee arthroplasty

The purpose of this study was to compare clinical outcomes of total knee arthroplasty (TKA) after manipulation under anaesthesia (MUA) for post-operative stiffness with a matched cohort of TKA patients who did not requre MUA.

In total 72 patients (mean age 59.8 years, 42 to 83) who underwent MUA following TKA were identified from our prospective database and compared with a matched cohort of patients who had undergone TKA without subsequent MUA. Patients were evaluated for range of movement (ROM) and clinical outcome scores (Western Ontario and McMaster Universities Arthritis Index, Short-Form Health Survey, and Knee Society Clinical Rating System) at a mean follow-up of 36.4 months (12 to 120). MUA took place at a mean of nine weeks (5 to 18) after TKA. In patients who required MUA, mean flexion deformity improved from 10° (0° to 25°) to 4.4° (0° to 15°) (p < 0.001), and mean range of flexion improved from 79.8° (65° to 95°) to 116° (80° to 130°) (p < 0.001). There were no statistically significant differences in ROM or functional outcome scores at three months, one year, or two years between those who required MUA and those who did not. There were no complications associated with manipulation.

At most recent follow-up, patients requiring MUA achieved equivalent ROM and clinical outcome scores when compared with a matched control group. While other studies have focused on ROM after manipulation, the current study adds to current literature by supplementing this with functional outcome scores.

Cite this article: Bone Joint J 2015;97-B:1640–4.

A randomised trial comparing a short and a standard-length metaphyseal engaging cementless femoral stem using radiostereometric analysis

This was a randomised controlled trial studying the safety of a new short metaphyseal fixation (SMF) stem. We hypothesised that it would have similar early clinical results and micromovement to those of a standard-length tapered Synergy metaphyseal fixation stem. Using radiostereometric analysis (RSA) we compared the two stems in 43 patients. A short metaphyseal fixation stem was used in 22 patients and a Synergy stem in 21 patients. No difference was found in the clinical outcomes pre- or post-operatively between groups. RSA showed no significant differences two years post-operatively in mean micromovement between the two stems (except for varus/valgus tilt at p = 0.05) (subsidence 0.94 mm (sd 1.71) vs 0.32 mm (sd 0.45), p = 0.66; rotation 0.96° (sd 1.49) vs 1.41° (sd 2.95), p = 0.88; and total migration 1.09 mm (sd 1.74) vs 0.73 mm (sd 0.72), p = 0.51). A few stems (four SMF and three Synergy) had initial migration > 1.0 mm but stabilised by three to six months, with the exception of one SMF stem which required revision three years post-operatively. For most stems, total micromovement was very low at two years (subsidence < 0.5 mm, rotation < 1.0°, total migration < 0.5 mm), which was consistent with osseous ingrowth. The small sample makes it difficult to confirm the universal applicability of or elucidate the potential contraindications to the use of this particular new design of stem.

Cite this article: Bone Joint J 2015; 97-B:595–602.

Outcomes and complications of total hip replacement in super-obese patients

The purpose of this study was to examine the complications and outcomes of total hip replacement (THR) in super-obese patients (body mass index (BMI) > 50 kg/m2) compared with class I obese (BMI 30 to 34.9 kg/m2) and normal-weight patients (BMI 18.5 to 24.9 kg/m2), as defined by the World Health Organization.

A total of 39 THRs were performed in 30 super-obese patients with a mean age of 53 years (31 to 72), who were followed for a mean of 4.2 years (2.0 to 11.7). This group was matched with two cohorts of normal-weight and class I obese patients, each comprising 39 THRs in 39 patients. Statistical analysis was performed to determine differences among these groups with respect to complications and satisfaction based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire.

Super-obese patients experienced significantly longer hospital stays and higher rates of major complications and readmissions than normal-weight and class I obese patients. Although super-obese patients demonstrated reduced pre-operative and post-operative satisfaction scores, there was no significant difference in improvement, or change in the score, with respect to HHS or the WOMAC osteoarthritis index.

Super-obese patients obtain similar satisfaction outcomes as class I obese and normal-weight patients with respect to improvement in their scores. However, they experience a significant increase in length of hospital stay and major complication and readmission rates.

Cite this article: Bone Joint J 2013;95-B:758–63.

Recent trends and clinical features of childhood vitamin D deficiency presenting to a children's hospital in Glasgow

BACKGROUND

The incidence of vitamin D deficiency is unclear in the context of continuing demographic changes and the introduction of new public health measures.

METHODS

All cases in which vitamin D deficiency was suspected as the primary cause of the clinical presentation were studied.

RESULTS

Between 2002 and 2008, 160 cases of symptomatic vitamin D deficiency were identified with twice as many cases in 2008 (n, 42) as in the previous years. The median age of the cohort was 24 months (range 2 weeks-14 years).Three cases were recorded in children of European background, whereas the rest were in children of South Asian, Middle Eastern or sub-Saharan ethnic background. Presenting features included bowed legs in 64 (40%) and a fit in 19 (12%). In one infant, concerns were raised following a presentation with cardiac failure and hypocalcaemia.

SUMMARY

Symptomatic vitamin D deficiency remains prevalent in the West of Scotland. There is a need for effective public health education, action and surveillance.

Altered sensitivity of deoxyadenosine-resistant mouse leukemia L1210 cells to apoptosis induced by 7-hydroxystaurosporine

The deoxyadenosine-resistant mouse leukemia L1210 cell line (Y8) has previously been shown to be more sensitive to apoptosis induced by DNA damaging agents and by protein synthesis inhibitors than the parental wild-type L1210 (WT) cells. These responses occur independently of p53 as both cell lines lack wild-type p53 function. Recent evidence suggests that a serine/threonine kinase is involved in the divergent cellular responses of the WT and Y8 cells. In the present study, the effects of 7-hydroxystaurosporine (UCN-01), a relatively specific serine/threonine kinase inhibitor, were examined in the WT and Y8 cells. Both cell lines were equally sensitive to the growth inhibitory effects of UCN-01. However, the Y8 cells accumulated in G0/G1 and became apoptotic. Apoptosis induced by UCN-01 in the Y8 cells was mediated by a caspase-3-like activity which could be partially blocked by Ac-DEVD-CHO, a caspase-3 inhibitor. UCN-01 did not alter the phosphorylation status of cdc2 nor cyclin B1 and cdc2 protein levels in either cell line.

Enhanced roscovitine-induced apoptosis is mediated by a caspase-3-like activity in deoxyadenosine-resistant mouse leukemia L1210 cells

The deoxyadenosine-resistant mouse leukemia L1210 cell line (Y8) has previously been shown to have phenotypic differences that appear to be unrelated to the altered properties observed at the level of ribonucleotide reductase (RR). One of these changes is that the Y8 cells do not express p53. In response to DNA damaging agents, x-irradiation and doxorubicin, both the parental wild-type L1210 (WT) and Y8 cells undergo G2/M arrest, which is consistent with cells lacking wild-type p53 function. However, Y8 cells are much more sensitive to apoptosis induced by these agents than WT cells. Previous studies have also shown that expression of certain genes involved in cell cycle regulation is different between WT and Y8 cells. Recent evidence suggests that a serine/threonine kinase is involved in the divergent cellular responses of these cells. In the present study, the effects of roscovitine, a cyclin-dependent kinase inhibitor, were examined on the WT and Y8 cells. The WT cells blocked in G2/M, whereas Y8 cells became apoptotic. Apoptosis induced by roscovitine in the Y8 cells was mediated by a caspase-3-like activity. NF kappa B was activated to a much greater extent by roscovitine in the WT cells than in Y8 cells. The data also indicate that cyclin B1/cdc2 plays a role in the divergent p53-independent G2/M block and apoptotic responses of the WT and Y8 cells, respectively. Several key factors such as cathepsin B, caspase-1, release of cytochrome c into the cytosol, TNF-alpha signaling, FasL/Fas signaling, c-myc overexpression, and E2F-1 overexpression and induction were shown not to be involved in the apoptotic pathway(s) in the Y8 cells.

Altered sensitivity of deoxyadenosine-resistant mouse leukemia L1210 cells to various kinase inhibitors

The deoxyadenosine-resistant mouse leukemia L1210 cell line (Y8) has previously been shown to have phenotypic differences that appear unrelated to the altered properties observed at the level of ribonucleotide reductase (RR). In response to various stress factors, the parental wild-type (WT) L1210 cell line undergoes cell cycle arrest; Y8 cells become apoptotic. These responses are p53-independent. Cell cycle regulation also appears different between the two cell lines, suggesting that Y8 cells are more apoptotic because of alterations in their cell cycle compared to WT cells. In order to study the relationships between cell cycle regulation and apoptosis, the effects of 2-aminopurine (2-AP), wortmannin, and PD98059, were studied on WT and Y8 cells. 2-AP induced G2/M block in both WT and Y8 cells with differences in G0/G1 and S phase contents between the two cell lines. Wortmannin induced G0/G1 block in Y8 cells, while exhibiting no effect on WT cells. PD98059 had no effect on the cell cycle of either WT or Y8 cells. In response to each inhibitor, Y8 cells underwent apoptosis to a much greater extent than the parental WT cell line. These data suggest that the specific pathways that converge on the cell cycle are altered and may be involved in the differences between a tumor cell to block in cell cycle or to undergo apoptosis.

Alterations in the properties of mouse leukemia L1210 cell lines selected by different methods for resistance to deoxyguanosine

Mouse leukemia L1210 cells were generated for resistance to deoxyguanosine by two different methods. In one case the L1210 cells were subjected to gradual increases in deoxyguanosine (dGuo-R); in the second approach, the cells were subjected to deoxyguanosine at a concentration ten times the IC50 value and plated out on soft agar (D-92). The dGuo-R and D-92 cell lines had different phenotypic expressions. The dGuo-R cells showed a higher degree of resistance to dGuo than the D-92 cells. The levels of resistance to other cytotoxic drugs such as araC or 2-chloro-2'-deoxyadenosine did not necessarily correlate with the degree of resistance to dGuo. Deoxycytidine kinase activity was decreased in both of the cell lines, although there was a larger decrease in the dGuo-R cell line. The levels of kinase activities toward the other substrates were not all coordinately decreased in these cell lines. The degree of resistance of these cell lines to dGuo cannot be ascribed solely to an alteration at the deoxycytidine kinase site.

Relevance of kinetic and metabolic data to the interpretation of toxicological findings

Metabolic and kinetic data on pesticides are now becoming an important part of the toxicological dossier required for product registration. In this paper the approach by one agrochemical company to generating such data is discussed. Metabolic data for the acaricide clofentezine are presented to illustrate why such data should be regarded as not only an important registration requirement, but also as integral to understanding the toxicological profile of pesticides.

The metabolism of fungicides

Of the three main groups of pesticides (insecticides, fungicides and herbicides), fungicides have probably the longest history, dating back to the accidental discovery in 1882 of Bordeaux mixture and the value of copper-based preparations for the control of vine downy mildew disease. In more recent times a wide range of fungicides have become available, including compounds with not only protectant but systemic activity, and total world-wide sales in 1983 were estimated at 2.8 billion dollars. This review attempts to summarize the current state of knowledge as it relates to the metabolism in animals and plants of examples of several of the major fungicide groups. Specifically the metabolism of maneb, mancozeb, zineb, captan, chlorothalonil, benomyl, triadimefon, triadimenol and cymoxanil are discussed.