Silicone radial head prostheses: the clinical course and treatment of failure-a case series.

INTRODUCTION: Silicone radial head prostheses (SRHP) have a reputation of acceptable initial function but failure in the medium to long term as a result of the disintegration of the silicone material. Damaged SRHP can result in a silicone-induced synovitis and destruction of the joint. Early removal of damaged SRHP may prevent joint destruction. Literature is scarce; there are no studies describing early symptoms associated with clinical failure of SRHP and very few studies on appropriate treatment of destructed SRHP. The aim of this study was to describe the clinical course of failing SRHP and to provide practical guidance for treatment. METHODS: Fifteen consecutive cases of failed SRHP, operated between 2005 and 2020, were retrospectively reviewed, using patient logs, radiographic results, and a questionnaire. Relevant data concerning pre- and postoperative complaints, function, and surgical details were gathered. Using the questionnaire, retrospective and current patient reported outcomes including Single Assessment Numeric Evaluation (SANE) scores, pain, instability, and range of motion were analyzed. RESULTS: The average time between implantation of the SRHP until outpatient presentation was 16 years. The average recalled SANE score before start of complaints was 8.6 out of 10 points. In 4 patients, the onset of complaints was preceded by a trauma. Five patients had symptoms for more than a year, and 9 patients for several months. Progressive pain in the elbow and/or wrist and mechanical symptoms were early and prominent symptoms of failure. Clinical signs of synovitis were frequently present. The majority of patients had a slow but progressive onset of complaints over several months before presentation. Twelve of 15 cases of failed SRHP were surgically treated. Fragmentation of the implant, osteoarthritis, and synovitis were found in all surgically treated cases. Both surgical removal and synovectomy alone, and revision to a new radial head prosthesis resulted in good medium-term outcomes with a mean SANE score of 7.3 points at 8.4 years of follow-up. Postoperative extension lags and mild instability were frequently mentioned as a reason for reimplantation of a metallic radial head implant and removal of the radial head alone, respectively. CONCLUSION: Both patients and physicians should be aware of early symptoms of a failing SRHP. Adequate recognition, radiographic evaluation, and early intervention may favor outcomes of failing SRHP. Surgical removal is easy to perform. In selected cases, revision of the radial head prosthesis may be considered. Both of these treatment strategies resulted in satisfying outcomes.

Impact of duration of macula-off retinal detachment on visual outcome: a systematic review and meta-analysis of literature.

PURPOSE: To systematically review the influence of the lag time between macula-off retinal detachment and surgical intervention on postoperative visual acuity as main outcome measure. METHODS: Systematic review and meta-analysis of articles published from 1995 to October 2013 of patients with macula-off retinal detachment and treated with scleral buckling or pars plana vitrectomy. Eligible data were pooled in a meta-analysis, analyzing the odds ratio between different durations of ≤ 3, ≤ 4, ≤ 7, and ≤ 10 days, comparing a final visual acuity of ≤ 0.4 logMAR with >0.4 logMAR, using a random-effects model. Last, the number needed to treat was calculated. RESULTS: Fourteen articles were eligible, of which 9 studies contained data that were suitable for meta-analysis. Patients who were operated with scleral buckling (n = 602) within 3 days since macular detachment had a statistically significant better chance of reaching a final visual acuity of 0.4 logMAR or better compared with a longer duration of macular detachment, with an odds ratio for ≤ 3 days versus 4 days to 7 days of 2.86 (95% confidence interval, 1.37-5.99) and an odds ratio for ≤ 3 days versus >3 days of 3.09 (95% confidence interval, 1.56-6.12), and with a number needed to treat of 4. For pars plana vitrectomy, the limited amount of data precluded a meta-analysis with substantial results. CONCLUSION: This meta-analysis suggests that scleral buckling for macular detachment must preferably be performed within 3 days to optimize visual outcome.

Silicone radial head prostheses revisited: do they have a role in today's practice? A systematic review of literature on clinical outcomes.

BACKGROUND: Silicone radial head prostheses (SRHP) are considered obsolete due to reports of frequent failure and destructive silicone-induced synovitis. Considering the good outcomes of modern non-radial silicone joint implants, the extent of scientific evidence for this negative view is unclear. The aim of this research was to systematically analyze the clinical evidence on complications and outcomes of SRHP and how SRHP compare to both non-SRHP and silicone prostheses of other joints. METHODS: A systematic literature review was conducted through the Cochrane, PubMed, and Embase databases. RESULTS: Eight cohort studies were included, consisting of 142 patients and follow-up periods ranging from 23 months to 8 years. Average patient satisfaction was 86%, range of 71%-100%, and 58 complications were seen, but no cases of synovitis. These outcomes were in line with non-SRHP. Four case series with 11 cases of synovitis were found, all due to implant fractures years to decades after implantation. Six systematic reviews of currently used non-radial silicone joint implants showed excellent outcomes with low complication rates. CONCLUSIONS: Since SRHP have satisfactory clinical results and an acceptable complication rate when selecting a patient group in suitable condition for surgical indications, it is considered that SRHP can still be chosen as a potential surgical treatment method in current clinical practice.

Reinforcement of hydrogels using three-dimensionally printed microfibres.

Despite intensive research, hydrogels currently available for tissue repair in the musculoskeletal system are unable to meet the mechanical, as well as the biological, requirements for successful outcomes. Here we reinforce soft hydrogels with highly organized, high-porosity microfibre networks that are 3D-printed with a technique termed as melt electrospinning writing. We show that the stiffness of the gel/scaffold composites increases synergistically (up to 54-fold), compared with hydrogels or microfibre scaffolds alone. Modelling affirms that reinforcement with defined microscale structures is applicable to numerous hydrogels. The stiffness and elasticity of the composites approach that of articular cartilage tissue. Human chondrocytes embedded in the composites are viable, retain their round morphology and are responsive to an in vitro physiological loading regime in terms of gene expression and matrix production. The current approach of reinforcing hydrogels with 3D-printed microfibres offers a fundament for producing tissue constructs with biological and mechanical compatibility.

Accumulation of drug resistance and loss of therapeutic options precede commonly used criteria for treatment failure in HIV-1 subtype-C-infected patients.

BACKGROUND: Virological monitoring is essential to identify antiretroviral treatment (ART) failure, but not widely available. Here, accumulation of resistance and consequences for second-line therapy were investigated in African HIV-1 subtype-C-infected patients. METHODS: A total of 836 patients initiated non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART and received biannual HIV RNA monitoring. When first-line ART was continued despite virological failure (HIV RNA>1,000 copies/ml), genotypic resistance analysis was performed at baseline, first failure (t1), and 6 or 12 months later (t2). Major resistance mutations (IAS), Stanford genotypic sensitivity scores (GSSs) and proportions of patients meeting WHO-defined failure criteria were compared between time points. RESULTS: Most patients (642/836, 77%) reached viral suppression and 145/642 patients (23%) experienced subsequent failure after a median of 18 months. Counselling resulted in virological re-suppression in 27% (39/145) and 40% (58/145) continued first-line ART despite virological failure; 26 patients were included for genotypic analysis.The mean number of major drug resistance mutations per person increased from 2.8 (t1) to 4.3 (t2). Initially, NNRTI-associated mutations (n=47) predominated; only 25 nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations (mainly M184V) were detected. During prolonged viraemia, NRTI resistance increased (n=44, +76%), in particular thymidine analogue mutations (from 4 to 14) and K65R (from 3 to 6). Consequently, GSSs declined from baseline to t1 and t2: from 3.8 to 1.0 to 0.7 (NNRTIs) and from 6.8 to 5.1 to 4.0 (NRTIs). Despite broad resistance, immunological failure was limited at t2. CONCLUSIONS: Rapid accumulation of drug resistance occurred when ART was continued despite virological failure. Treatment options were lost, even when WHO-defined failure criteria were not met. This study calls for wider access to virological monitoring.