The influence of biological DMARDs on aseptic arthroplasty loosening: a retrospective cohort study

OBJECTIVE

To investigate whether biological DMARDs affect the risk of aseptic loosening after total hip/knee arthroplasty (THA/TKA) in patients with RA.

METHODS

We retrospectively identified all patients suffering from RA who underwent THA/TKA at our academic centre between 2002 and 2015 and linked them with an existing prospective observational RA database at our institution. The risk of aseptic loosening was estimated using radiological signs of component loosening (RCL). A time-dependent Cox regression analysis was used to compare the risk of implant loosening between patients treated with traditional DMARDS and biological DMARDs, or alternately both over time.

RESULTS

A total of 155 consecutive total joint arthroplasties (TJAs) (103 TKA vs 52 THA) was retrospectively included in the study. Mean age at implantation was 59 ± 13 years. Mean follow-up time was 69 ± 43 months. Overall, 48 (31%) TJAs showed signs of RCL, with 28 (27.2%) RCLs occurring after TKA compared with 20 after THA (38.5%). A significant difference regarding the incidence of RCL between the traditional DMARDs group (39 cases of RCL, 35%) and the biological DMARDs group (nine cases of RCL, 21%) (P = 0.026) was observed using the log-rank test. This was also true when using a time-dependent Cox regression with therapy as well as arthroplasty location (hip vs knee) as variables (P = 0.0447).

CONCLUSION

Biological DMARDs may reduce the incidence of aseptic loosening after TJA in patients with RA compared with traditional DMARDs. This effect seems to be more pronounced after TKA than THA.

Two-stage revision for periprosthetic joint infection after hip and knee arthroplasty

Aims

Histology is widely used for diagnosis of persistent infection during reimplantation in two-stage revision hip and knee arthroplasty, although data on its utility remain scarce. Therefore, this study aims to assess the predictive value of permanent sections at reimplantation in relation to reinfection risk, and to compare results of permanent and frozen sections.

Methods

We retrospectively collected data from 226 patients (90 hips, 136 knees) with periprosthetic joint infection who underwent two-stage revision between August 2011 and September 2021, with a minimum follow-up of one year. Histology was assessed via the SLIM classification. First, we analyzed whether patients with positive permanent sections at reimplantation had higher reinfection rates than patients with negative histology. Further, we compared permanent and frozen section results, and assessed the influence of anatomical regions (knee versus hip), low- versus high-grade infections, as well as first revision versus multiple prior revisions on the histological result at reimplantation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), chi-squared tests, and Kaplan-Meier estimates were calculated.

Results

Overall, the reinfection rate was 18%. A total of 14 out of 82 patients (17%) with positive permanent sections at reimplantation experienced reinfection, compared to 26 of 144 patients (18%) with negative results (p = 0.996). Neither permanent sections nor fresh frozen sections were significantly associated with reinfection, with a sensitivity of 0.35, specificity of 0.63, PPV of 0.17, NPV of 0.81, and accuracy of 58%. Histology was not significantly associated with reinfection or survival time for any of the analyzed sub-groups. Permanent and frozen section results were in agreement for 91% of cases.

Conclusion

Permanent and fresh frozen sections at reimplantation in two-stage revision do not serve as a reliable predictor for reinfection.

Thirty-Year Minimum Follow-Up Outcome of a Straight Cementless Rectangular Stem

BACKGROUND

Meta-diaphyseal fixation of straight, tapered, uncemented stems has been proven to be very reliable for total hip arthroplasty in 10 to 20 years of follow-up studies. The aim of the study was to evaluate whether the implant survival as well as radiological and functional outcome have changed in patients with a minimum follow-up of 30 years.

METHODS

From a total of 210 patients, who received a straight, rectangular, tapered cementless stem and a threaded cup, there were 37 total hip arthroplasties (33 patients) still available for follow-up after a minimum of 30 years. Patients were examined clinically and radiographically, and revision surgeries were recorded.

RESULTS

There was a low rate of revisions of the femoral stem with a survival probability of 0.92 (confidence interval 0.85 to 0.96) at 30 years. Survival probability of the acetabular component decreased drastically with 0.45 (confidence interval 0.30 to 0.59). Radiographic analysis of the stem revealed radiolucencies in 73% (n = 16), but only in the proximal/metaphyseal part and none of the stems were radiographically loose.

CONCLUSION

In this minimum 30-year follow-up study, a straight rectangular cementless implant continues to provide excellent implant survival and high patient satisfaction. However, survival rates of the whole total hip replacement system were reduced by a high revision rate due to wear-related problems.

Early postoperative laboratory parameters are predictive of initial treatment failure in acute septic arthritis of the knee and shoulder joint

Septic arthritis is an orthopedic emergency potentially causing irreversible joint damage. However, the predictive value of potential risk factors such as early postoperative laboratory parameters remains uncertain. We investigated risk factors for initial surgical treatment failure using data from 249 patients (194 knees, 55 shoulders) treated for acute septic arthritis between 2003 and 2018. Necessity for further surgical intervention was defined as primary outcome. Demographic data, medical history, initial and postoperative laboratory parameters, Charlson Comorbidity Index (CCI), and Kellgren and Lawrence classification were collected. Two scoring systems were developed as tools for failure risk estimation after initial surgical irrigation and debridement. More than one intervention was necessary in 26.1% of cases. Treatment failure occurred significantly more often for those with longer symptom duration (p = 0.003), higher CCI grades (p = 0.027), Kellgren-Lawrence grade IV (p = 0.013), shoulder arthroscopy (p = 0.010), positive bacterial culture results (p < 0.001), slow postoperative CRP decline until day three (p = 0.032) and five (p = 0.015), reduced WBC-decline (p = 0.008), and lower hemoglobin (p < 0.001). Scores for third and fifth postoperative day achieved AUCs of 0.80 and 0.85, respectively. This study identified risk factors for treatment failure in patients with septic arthritis, suggesting that early postoperative laboratory parameters can guide further treatment.

Do Elevated Serum C-Reactive-Protein Levels Excuse Delayed Surgery for Femoral Neck Fractures?

In elderly patients with femoral neck fractures, preoperative serum C-reactive protein (CRP) values might be elevated due to active infections. Although there are limited data on CRP as a predictor of periprosthetic joint infection (PJI), out of concern, this could lead to delayed surgery. Therefore, we aim to investigate whether elevated serum-CRP levels justify delayed surgery for femoral neck fractures. A retrospective analysis was performed of the records of patients undergoing arthroplasty who were found to have an elevated CRP level of 5 mg/dL or more between January 2011 to December 2020. The patients were stratified to three groups, according to initial serum CRP levels at a cut off of 5 mg/dL and the time between admission and surgery (<48 vs. ≥48 h after admission). This study revealed that the patients with elevated serum CRP levels and delayed surgery showed a worse survival rate and significantly more postoperative complications than the patients on whom surgery was performed immediately. There were no significant differences in terms of PJI and prolonged wound healing in the inter-group comparison. Therefore, delays to surgery on the basis of elevated CRP values offer no benefits to patients with femoral neck fractures.

Long Term Results of a Rotating Hinge Total Knee Prosthesis With Carbon-Fiber Reinforced Poly-Ether-Ether-Ketone (CFR-PEEK) as Bearing Material

Background: The use of rotating hinge (RH) prostheses for severe primary as well as revision arthroplasty is widely established. Due to the steadily increasing number of RH prostheses, we aimed to assess the complication frequencies, complication types and clinical outcomes of a modern RH hinge prosthesis using a new bearing material with a minimum follow-up of 7 years.

Methods: Fifty-six consecutive patients who received the EnduRo^® RH prosthesis using carbon-fiber reinforced poly-ether-ether-ketone (CFR-PEEK) as bearing material were included in this prospective study: 21 patients (37.5%) received the prosthesis as a primary total knee arthroplasty (TKA) and 35 patients (62.5%) underwent revision total knee arthroplasties (rTKA). Clinical and radiographic examinations were performed preoperatively, postoperatively after three and 12 months and annually thereafter. Clinical scores were documented for each patient. Competing risk analysis was assessed with respect to indication and failure mode.

Results: Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS) and range of motion (ROM) improved significantly compared to preoperative values (p < 0.0001). The overall cumulative incidence for revision surgery was 23.6% at 7 years and the cumulative incidence for complications associated with failure of the prothesis was 5.6% at 7 years, respectively. Complications occurred more frequently in the revision group (p = 0.002).

Conclusion: The evaluated RH prosthesis provided reliable and durable results for a minimum follow-up of 7 years. Prosthesis survival was successful considering the complexity of the cases. The use of this RH system in primary patients showed high survival rates and long-term functional outcomes and clinical outcomes proved to be satisfying in both revision and primary cases. No adverse events were associated with the new bearing material CFR-PEEK.

A biomechanical in-vitro study on an alternative fixation technique of the pubic symphysis for open book injuries of the pelvis

PURPOSE

Implant failure rates remain high after plate fixation in pelvic ring injuries. The aim of this study was to compare an alternative fixation technique with suture-button devices and anterior plate fixation in partially stable open-book injuries.

MATERIAL AND METHODS

We acquired 16 human fresh frozen anatomic pelvic specimens. The sacrospinous, sacrotuberous, and anterior sacroiliac ligaments were bilaterally released, and the pubic symphysis transected to simulate a partially stable open-book (AO/OTA 61-B3.1) injury. The specimens were randomly assigned to the two fixation groups. In the first group two suture-button devices were placed in a criss-crossed position through the symphysis. In second group a six-hole plate with standard 3.5 unlocked bicortical screws was used for fixation. Biomechanical testing was performed on a servo-hydraulic apparatus simulating bilateral stance, as described by Hearn and Varga. Cyclic compression loading with a progressively increasing peak load (0.5 N/cycle) was applied until failure. The failure mode, the load and the number of cycles at failure and the proximal and distal distance of the symphysis during testing were compared.

RESULTS

There was no implant failure in either of the two groups. Failures occurred in nine pelvises (56.2%) at the fixation between the sacrum and the mounting jig and in seven pelvises (43.8%) in the sacroiliac joint. Neither the ultimate load nor the number of cycles at failure differed between the surgical techniques (p = 0.772; p = 0.788, respectively). In the suture button group the mean ultimate load was 874.5 N and the number of cycles at failure was 1907.9. In the plate group values were 826.1 N and 1805.6 cycles, respectively. No significant differences at proximal and distal diastasis of the symphysis were monitored during the whole loading process.

CONCLUSION

The fixation with suture button implants showed comparable results to anterior plate fixation in open-book injuries of the pelvis.

[Sexual Self-esteem in Trans*People: Development of a New Questionnaire and Clinical Evaluation]

AIM OF THE STUDY

Our purpose was to develop a new instrument for the assessment of sexual self-esteem in German and to examine its psychometric properties. Subsequently, we aimed to investigate sexual self-esteem in trans*people.

METHODS

The construction and validation of the sexual self-esteem scale was realized in a sample of the general population (N=426; Study 1, online) based on confirmatory factor analysis and statistical item analysis. We then investigated an outpatient sample of trans*people (N=85; study 2) to compare sexual self-esteem with the population sample and to examine the associations between sexual self-esteem, body experience, and psychological and psychosomatic distress.

RESULTS

An acceptable model fit and good internal consistency for the final unidimensional 8-item solution of the sexual self-esteem scale (SSES) were confirmed. Sexual self-esteem was moderately associated with global self-esteem in the population sample. Trans*people showed a significantly lower sexual self-esteem compared to the normal population. Results also revealed the expected associations with body experience, but no association with psychological and psychosomatic distress.

CONCLUSION

The SSES is the first German-language and gender-neutral instrument to assess sexual self-esteem and provides good psychometric properties. It appears promising for monitoring the course and success of the transition treatment of trans*people as well as for its application in couples and sexual therapy.

Diagnostic accuracy of neutrophil counts in histopathological tissue analysis in periprosthetic joint infection using the ICM, IDSA, and EBJIS criteria

Aims

Histology is an established tool in diagnosing periprosthetic joint infections (PJIs). Different thresholds, using various infection definitions and histopathological criteria, have been described. This study determined the performance of different thresholds of polymorphonuclear neutrophils (≥ 5 PMN/HPF, ≥ 10 PMN/HPF, ≥ 23 PMN/10 HPF) , when using the European Bone and Joint Infection Society (EBJIS), Infectious Diseases Society of America (IDSA), and the International Consensus Meeting (ICM) 2018 criteria for PJI.

Methods

A total of 119 patients undergoing revision total hip (rTHA) or knee arthroplasty (rTKA) were included. Permanent histology sections of periprosthetic tissue were evaluated under high power (400× magnification) and neutrophils were counted per HPF. The mean neutrophil count in ten HPFs was calculated (PMN/HPF). Based on receiver operating characteristic (ROC) curve analysis and the z-test, thresholds were compared.

Results

Using the EBJIS criteria, a cut-off of ≥ five PMN/HPF showed a sensitivity of 93% (95% confidence interval (CI) 81 to 98) and specificity of 84% (95% CI 74 to 91). The optimal threshold when applying the IDSA and ICM criteria was ≥ ten PMN/HPF with sensitivities of 94% (95% CI 79 to 99) and 90% (95% CI 76 to 97), and specificities of 86% (95% CI 77 to 92) and 92% (95% CI 84 to 97), respectively. In rTKA, a better performance of histopathological analysis was observed in comparison with rTHA when using the IDSA criteria (p < 0.001).

Conclusion

With high accuracy, histopathological analysis can be supported as a confirmatory criterion in diagnosing periprosthetic joint infections. A threshold of ≥ five PMN/HPF can be recommended to distinguish between septic and aseptic loosening, with an increased possibility of detecting more infections caused by low-virulence organisms. However, neutrophil counts between one and five should be considered suggestive of infection and interpreted carefully in conjunction with other diagnostic test methods.

Cite this article: Bone Joint Res 2021;10(8):536–547.

Proximal femoral reconstruction with modular megaprostheses in non-oncological patients

Introduction

Multiple revision hip arthroplasties and critical trauma might cause severe bone loss that requires proximal femoral replacement (PFR). The aim of this retrospective study was to analyse complication- and revision-free survivals of patients who received modular megaprostheses in an attempt to reconstruct massive non-neoplastic bone defects of the proximal femur.

Questions/purposes

(1) What were general complication rates and revision-free survivals following PFR? (2) What is the incidence of complication specific survivals? (3) What were risk factors leading to a diminished PFR survival?

Materials and methods

Twenty-eight patients with sufficient follow-up after receiving a modular proximal femoral megaprosthesis were identified. The indications for PFR included prosthetic joint infection (PJI), periprosthetic fracture, aseptic loosening, non-union and critical femoral fracture. Complications were grouped according to the ISOLS-classification of segmental endoprosthetic failure by Henderson et al.

Results

Overall, the complication-free survival was 64.3% at one year, 43.2% at five years and 38.4% at ten years, with 16 patients (57%) suffering at least one complication. Complications were dislocation in eight patients (29%), PJI in 6 patients (21%), periprosthetic fracture in five patients (18%), and aseptic loosening in six patients (21%). Prosthesis stem cementation showed a lower risk for revision in a cox proportional hazard model (95% CI 0.04–0.93, HR 0.2, p = 0.04).

Conclusion

PFR with modular megaprostheses represents a viable last resort treatment with high complication rates for patients with severe proximal femoral bone loss due to failed arthroplasty or critical fractures. In revision arthroplasty settings, PFR cementation should be advocated in cases of impaired bone quality.

Modular megaprostheses in the treatment of periprosthetic fractures of the femur

Background

Periprosthetic fractures (PPF) of the femur remain challenging, especially in patients with previous multiple revisions. Modular megaprostheses (mMPs) are rarely used in this indication; however, in some cases mMPs seem to be the last chance for limb salvage. We aimed to evaluate the clinical outcome of PPFs of the femur treated by modular mMPs at our institution.

Patients and methods

In this study 33 patients (27 female; mean age 79 years) with a PPF after total hip or total knee arthroplasty (no tumor indications) were treated using modular proximal (mPFR; n = 12), distal (mDFR; n = 14) or total (mTFR; n = 7) femur replacement. A retrospective evaluation regarding mortality and revision rates was performed. Failures with need for revision were classified.

Results

At a mean follow up of 60 months (range 0–178 months), the total mortality rate as well as total revision rate were both found to be 39%. At 1 year follow-up the mortality rate was highest within the mDFR group, and less revisions were necessary in the mPFR group, however both findings were not significantly. Those patients, who had revision surgery before PPF, were found to have higher revision rate after implantation of mMP. In the mPFR group, dislocation was the most frequent failure, within the mDFR and the mTFR group infection. In one case amputation of the lower limb was necessary.

Conclusion

mMPs represent a valuable option in PPFs of the femur. Infection and dislocation remain the most frequent complications. Prospective clinical studies are required to further define the outcome of mMPs in PPFs of the femur.

Sonication culture improves microbiological diagnosis of modular megaprostheses

Modular megaprostheses are known for high infection rates followed by high rates of revisions. Microbial biofilms growing adherently on prosthetic surfaces may inhibit the detection of the pathogens causing prosthetic joint infections. We sought to answer the following questions: Does sonication culture (SC) improve the microbiological diagnosis of periprosthetic infections of megaprostheses compared to conventional tissue culture (TC)? Which pathogens were detected on the surface of megaprostheses with either SC or TC and do the findings help to identify low-grade infections? Included were 31 patients with modular megaprostheses, whose implant had been explanted due to suspected joint infection or revision surgery. SCs were performed according to the protocol by Trampuz et al. The diagnosis of infection was evaluated according to the definition of the Musculoskeletal Infection Society. The sensitivity of SC was 91.3% compared to 52.2% for TC and the specificity was 100% for SC and TC (p = 0.004). Under preoperative antibiotic therapy, the sensitivity of SC was 83.3% while the sensitivity of TC was 50%. Without preoperative antibiotic therapy the sensitivity of SC was 100% compared to 54.5% for TC. In nine cases, SCs detected microorganisms, while TC was negative. Detected bacteria were Staphylococcus epidermidis in four, Micrococcus species in one, Finegoldia magna in one, Brevibacterium casei in one, Pseudomonas fluorescens in one, and Enterococcus faecium in one. SC is a reliable method for dislodging pathogens from orthopedic implants. The SC of modular megaprostheses showed significantly higher pathogen detection than the periprosthetic TC, especially for low virulence pathogens. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1383-1387, 2017.

Oncological and surgical outcome after treatment of pelvic sarcomas

Background and objectives

Treatment of pelvic tumors remains challenging due to complex anatomy, poor oncological outcome and high complication rates. We sought to investigate the long-term oncological and surgical outcome of these patients.

Methods

Between 1980 and 2012, 147 patients underwent surgical treatment for pelvic sarcoma. Histological diagnosis was Chondrosarcoma in 54, Ewing’s Sarcoma/PNET in 37, Osterosarcoma in 32 and others in 24 patients. Statistical analysis for the evaluation of oncological and surgical outcome was performed by applying Cox proportional hazards regression and Fine-Gray regression models for competing risk (CR) endpoints.

Results

The estimated overall survival (OS) to death was 80%, 45% and 37% at 1, 5 and 10 years, respectively. Univariate analyses revealed a statistically significant unadjusted influence of age age (p = 0.038; HR = 1.01), margin (p = 0.043; HR = 0.51) and grade (p = 0.001; HR = 2.27) on OS. Considering the multivariable model, grade (p = 0.005; HR = 3.04) and tumor volume (p = 0.014; HR = 1.18) presented themselves as independent prognostic factors on OS. CR analysis showed a cumulative incidence for major complication of 31% at 5 years. Endoprosthetic reconstruction had a higher risk for experiencing a major complication (p<0.0001) and infection (p = 0.001).

Conclusions

Pelvic resections are still associated with a high incidence of complications. Patients with pelvic reconstruction and high volume tumors are especially at risk. Consequently, a cautious decision-making process is necessary when indicating pelvic reconstruction, although a restrictive approach to pelvic reconstruction is not necessarily reasonable when the other option is major amputation.

Qualitative α-defensin test (Synovasure) for the diagnosis of periprosthetic infection in revision total joint arthroplasty

AIMS

The diagnosis of periprosthetic joint infection (PJI) remains demanding due to limitations of all the available diagnostic tests. The synovial fluid marker, α-defensin, is a promising adjunct for the assessment of potential PJI. The purpose of this study was to investigate the qualitative assessment of α-defensin, using Synovasure to detect or exclude periprosthetic infection in total joint arthroplasty.

PATIENTS AND METHODS

We studied 50 patients (28 women, 22 men, mean age 65 years; 20 to 89) with a clinical indication for revision arthroplasty who met the inclusion criteria of this prospective diagnostic study. The presence of α-defensin was determined using the qualitative Synovasure test and compared with standard diagnostic methods for PJI. Based on modified Musculoskeletal Infection Society (MSIS) criteria, 13 cases were categorised as septic and 36 as aseptic revisions. One test was inconclusive.

RESULTS

The Synovasure test achieved a sensitivity of 69% and a specificity of 94%. The positive and negative likelihood ratios were 12.46 and 0.33, respectively. A good diagnostic accuracy for PJI, with an area under the curve of 0.82, was demonstrated. Adjusted p-values using the method of Hochberg showed that Synovasure is as good at diagnosing PJI as histology (p = 0.0042) and bacteriology with one positive culture (p = 0.0327).

CONCLUSION

With its ease of use and rapid results after approximately ten minutes, Synovasure may be a useful adjunct in the diagnosis of PJI. Cite this article: Bone Joint J 2017;99-B:66-72.

Treatment of septic arthritis of the knee: a comparison between arthroscopy and arthrotomy

PURPOSE

The aim of this study was to compare the efficacy of arthroscopy and arthrotomy in patients with septic monarthritis of the knee.

METHODS

Seventy consecutive patients who underwent surgery because of a bacterial monarthritis were evaluated. Patients were either treated with arthroscopy or with arthrotomy. Our primary outcome was the early recurrence of infection (>3 months after surgery), which made a second surgical procedure necessary. Furthermore, the influence of potential confounders on treatment outcome was analysed.

RESULTS

Of the 70 patients, 41 were treated arthroscopically and 29 with arthrotomy. Eight patients (11.4 %) had to undergo a second surgical procedure because of early re-infection. The rate was significantly higher in patients treated with arthrotomy (n = 6; 20.7 %) compared with those treated by arthroscopy (n = 2) (p = 0.041). Range of motion was significantly better in patients who underwent arthroscopy (p < 0.001). Male sex had negative influence on the treatment success (p = 0.03).

CONCLUSIONS

Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower re-infection rate and a better functional outcome than those treated with arthrotomy. As arthroscopy is the less invasive method, it should be considered the routine treatment, according to our data.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

Outcome after Reconstruction of the Proximal Tibia--Complications and Competing Risk Analysis

Background and Objectives

The proximal tibia (pT) is a common site for bone tumors. Improvements in imaging, chemotherapy and surgical technique made limb salvage surgery the treatment of choice. Yet, reconstructions of the pT have been associated with less favorable outcome compared to other parts of the extremities. The aim of this study was to evaluate the outcome of patients with a modular endoprosthetic reconstruction of the pT.

Methods

Eighty-one consecutive patients with an average age of 29 years underwent endoprosthetic reconstruction of the pT. Postoperative complications were categorized according to the ISOLS classification, and revision-free survival until first complication (any Type 1–5), soft tissue failure (Type 1), aseptic loosening (Type 2), structural failure (Type 3), infection (Type 4), and local tumor progression (Type 5) was estimated by using a Fine-Gray model for competing risk analyses for univariate and multivariable regression with Firth’s bias correction.

Results

A total of 45 patients (56%) had at least one complication. Cumulative incidence for complication Types 1 to 5 at 5 years with death and amputation as competing events revealed a risk of 41% for the first complication, 14% for Type 1, 16% for Type 2, 11% for Type 3, 17% for Type 4, and 1% for Type 5.

Conclusion

Despite inclusion of amputation and death as strong competing events, pT replacements are still associated with a high risk of postoperative failures. The results suggest that infection and soft tissue failures (Type 1 and 5) seem to depend from each other. Sufficient soft tissue reconstruction and closure allow better function and reduce the risk of infection as the most prominent complication. The use of a rotating hinge design has significantly reduced structural failures over time.

Serological changes in the course of traditional and biological disease modifying therapy of rheumatoid arthritis

OBJECTIVE

To investigate changes of rheumatoid factor (RF) and antibodies against citrullinated peptides (ACPA) during therapy with disease modifying antirheumatic drugs.

METHODS

We obtained clinical and serological data of patients from the treatment start and after 6 months of therapy. With non-parametric tests, we analysed changes of ACPA and RF levels between the two visits and the influence of treatment response. Furthermore, we analysed potential influential factors as disease chronicity, different therapeutics and the trend over 18 months.

RESULTS

143 ACPA and RF positive patients were included. The median (25th/75th percentile) relative changes after 6 months were -35.6% (-63.3; -8.3) for RF and -15.2% (-40.0; 10.0) for ACPA (p<0.001 for both). Changes of RF levels were significantly greater than those seen for ACPA (p<0.001). The decrease of ACPA and RF was significantly higher in treatment responders (p=0.034 and p=0.01, respectively). Aside from changes in disease activity, only a short disease duration showed an independent effect on changes of RF levels (p=0.087).

CONCLUSIONS

ACPA and RF levels decreased significantly after 6 months of therapy. Reductions of both autoantibodies were closely linked to a reduction of disease activity. RF declined faster, to a larger extent and in greater numbers of patients than ACPA.

Rheumatoid arthritis and falls: the influence of disease activity

OBJECTIVE

To examine the correlation between disease activity of RA and the risk of falling.

METHODS

Seventy-eight patients were tested. Disease activity was measured with acute-phase reactants, autoantibodies, swollen and tender joint count (SJC28, TJC28), pain on a visual analogue scale (VAS pain), patient and evaluator global assessment of disease activity (PGA, EGA), HAQ disability index (HAQ-DI), 28-joint DAS (DAS-28) and the clinical and simple disease activity indexes (CDAI, SDAI). The risk of falling was evaluated by a fall assessment consisting of Tinetti test (TIT), timed get up and go test (TUG), chair-rising test (CRT), tandem walk and tandem stand test.

RESULTS

During the last 12 months, 26.9% of the participants reported a fall and 46.2% mentioned the fear of falling. The most evident link [Spearman's correlation (r(s))] with the results of the fall assessment was found in HAQ-DI (CRT: r(s) = 0.523, TUG: r(s) = 0.620, TIT: r(s) = -0.676), CDAI (CRT: r(s) = 0.460, TUG: r(s) = 0.504, TIT: r(s) = -0.472), VAS pain (CRT: r(s) = 0.441, TUG: r(s) = 0.616, TIT: r(s) = -0.548) PGA (CRT: r(s) = 0.473, TUG: r(s) = 0.577, TIT: r(s) = -0.520) and TJC (CRT: r(s) = 0.488, TUG: r(s) = 0.394, TIT: r(s) = -0.385). Patients with higher disease activity achieved poorer results in the fall assessment.

CONCLUSION

The strongest correlation with falls was evident for patient-reported outcomes. Pain seems to be the common ground of these parameters. At the same time, disease activity influences pain. The results suggest an increased attention towards the risk of falling with patients of higher levels of disease activity or pain, and physio- or ergotherapeutical interventions as needed.

Effect of controlled laser microporation on drug transport kinetics into and across the skin

The objectives of this study were to investigate a novel laser microporation technology ( P.L.E.A.S.E. Painless Laser Epidermal System) and to determine the effect of pore number and depth on the rate and extent of drug delivery across the skin. In addition, the micropores were visualized by confocal laser scanning microscopy and histological studies were used to determine the effect of laser fluence (energy applied per unit area) on pore depth. Porcine ear skin was used as the membrane for both the pore characterization and drug transport studies. Confocal images in the XY-plane revealed that the pores were typically 150-200 microm in diameter. Histological sections confirmed that fluence could be used to effectively control pore depth - low energy application (4.53 and 13.59 J/cm(2)) resulted in selective removal of the stratum corneum (20-30 microm), intermediate energies (e.g., 22.65 J/cm(2)) produced pores that penetrated the viable epidermis (60-100 microm) and higher application energies created pores that reached the dermis (>150-200 microm). The effects of pore number and pore depth on molecular transport were quantified by comparing lidocaine delivery kinetics across intact and porated skin samples. After 24h, cumulative skin permeation of lidocaine with 0 (control), 150, 300, 450 and 900 pores was 107+/-46, 774+/-110, 1400+/-344, 1653+/-437 and 1811+/-642 microg/cm(2), respectively; there was no statistically significant difference between 300, 450 and 900 pore data - probably due to the effect of drug depletion since >50% of the applied dose was delivered. Importantly, increasing fluence did not produce a statistically significant increase in lidocaine permeation; after 24h, cumulative lidocaine permeation was 1180+/-448, 1350+/-445, 1240+/-483 and 1653+/-436 microg/cm(2) at fluences of 22.65, 45.3, 90.6 and 135.9 J/cm(2), respectively. Thus, shallow pores were equally effective in delivering lidocaine. Increasing lidocaine concentration in the formulation from 10 to 25mg/ml produced a corresponding increase in permeation (at 24h, 1650+/-437 and 4005+/-1389 microg/cm(2), respectively). The validity of the porcine skin model was confirmed as transport across porcine and human skins was shown to be statistically equivalent (at 24h, 1811+/-642 and 2663+/-208 microg/cm(2), respectively). The clinical potential of the technology and its capacity to provide significantly faster delivery than conventional passive administration was demonstrated in short duration experiments involving application of a marketed lidocaine cream (LMX4) to laser-porated skin; after only 5 min of formulation application, lidocaine deposition was measured at 61.3+/-7.5 microg/cm(2). In conclusion, the results demonstrate the ability of P.L.E.A.S.E.(R) (i) to create well-defined conduits in the skin, (ii) to provide a controlled enhancement of transdermal transport and (iii) to enable improvement in both the rate and extent of drug delivery.

Polymerization on the rocks: negatively-charged alpha-amino acids

Oligomers of the negatively-charged amino acids, glutamic acid, aspartic acid, and O-phospho-L-serine are adsorbed by hydroxylapatite and illite with affinities that increase with oligomer length. In the case of oligo-glutamic acids adsorbed on hydroxylapatite, addition of an extra residue results in an approximately four-fold increase in the strength of adsorption. Oligomers much longer than the 7-mer are retained tenaciously by the mineral. Repeated incubation of short oligo-glutamic acids adsorbed on hydroxylapatite or illite with activated monomer leads to the accumulation of oligomers at least 45 units long. The corresponding reactions of aspartic acid and O-phospho-L-serine on hydroxylapatite are less effective in generating long oligomers, while illite fails to accumulate substantial amounts of long oligomers of aspartic acid or of O-phospho-L-serine.

Template switching between PNA and RNA oligonucleotides

The origin of the RNA world is not easily understood, as effective prebiotic syntheses of the components of RNA, the beta-ribofuranoside-5'-phosphates, are hard to envisage. Recognition of this difficulty has led to the proposal that other genetic systems, the components of which are more easily formed, may have preceded RNA. This raises the question of how transitions between one genetic system and another could occur. Peptide nucleic acid (PNA) resembles RNA in its ability to form double-helical complexes stabilized by Watson-Crick hydrogen bonding between adenine and thymine and between cytosine and guanine, but has a backbone that is held together by amide rather than by phosphodiester bonds. Oligonucleotides bases on RNA are known to act as templates that catalyse the non-enzymatic synthesis of their complements from activated mononucleotides, we now show that RNA oligonucleotides facilitate the synthesis of complementary PNA strands and vice versa. This suggests that a transition between different genetic systems can occur without loss of information.