Loosening and revision rates after total shoulder arthroplasty: a systematic review of cemented all-polyethylene glenoid and three modern designs of metal-backed glenoid.

BACKGROUND: Several modern designs of metal-backed glenoids (MBG) have been devised to overcome flaws such as loosening and a high failure rate. This review aimed to compare rates of complications and revision surgeries between cemented polyethylene glenoid (PEG) and three examples of modern MBG designs. METHODS: Literature search was carried out using PubMed, Cochrane Library, EMBASE, and Google Scholar using MeSH terms and natural keywords. A total of 1186 articles were screened. We descriptively analyzed numerical data between the groups and statistically analyzed the categorical data, such as the presence of radiolucent line, loosening, and revision surgery (failure). Articles were divided into three groups based on follow-up duration: < 36-month, 36-72-month, and > 72-month subgroups. RESULTS: This study included 35 articles (3769 shoulders); 25 on cemented PEG and ten on the modern MBG. Mean age was 66.4 (21-93) and 66.5 years (31-88). The mean duration of follow-up was 73.1 (12-211) and 56.1 months (24-100). Overall, the rate of the radiolucent line was 354/1302 (27%) and 47/282 (17%), the loosening rate was 465/3185 (15%) and 22/449 (5%), and the failure rate was 189/3316 (6%) and 11/457 (2%), for PEG and MBG, respectively. The results of < 36-month and 36-72-month subgroups showed lower rates of radiolucency and loosening in the cemented PEG group, but there was no significant difference in failure rate (P = 0.754 and 0.829, respectively). In the > 72-month subgroup, MBG was better in terms of loosening (P < 0.001) and failure rates (P = 0.006). CONCLUSIONS: The modern MBG component, especially TM glenoid, seems to be a promising alternative to cemented PEGs, based on subgroup revision rates according to the follow-up duration and overall results of ROM and clinical scores. All polyethylene glenoids tend to increase loosening and failure over time. Three modern MBG designs seem to have no difference in failure, at least in the < 36-month and 36-72-month subgroups compared to the cemented PEG. More long-term follow-up studies on modern MBG should be ultimately conducted. LEVEL OF EVIDENCE: Level IV, systematic review.

Update on metal-induced occupational lung disease.

PURPOSE OF REVIEW: Occupational and environmental exposures to metals can result in multiple pulmonary conditions. This article will review recent epidemiologic and mechanistic studies that have enhanced our understanding of the association between particular lung diseases and exposure to specific metals. RECENT FINDINGS: Recent studies have broadened our understanding of the mechanisms of lung diseases such as CBD in established industries and drawn attention to conditions that may arise from exposure to metals such as indium in developing technologies. New diagnostic techniques such as elemental tissue analysis may help establish a diagnosis of metal-induced occupational lung disease. Electronic cigarette devices, environmental pollutants, and the growing use of nanoparticle-sized metals pose additional risks to workers and consumers. SUMMARY: Recognizing the risks of pulmonary disease in workers exposed to metals and performing a thorough occupational history and diagnostic work-up in patients with unexplained respiratory findings is necessary to promote understanding and prevention of metal-induced lung disease.

Distribution, enrichment, and potential toxicity of trace metals in the surface sediments of Sundarban mangrove ecosystem, Bangladesh: a baseline study before Sundarban oil spill of December, 2014.

The distribution, enrichment, and ecotoxicity potential of Bangladesh part of Sundarban mangrove was investigated for eight trace metals (As, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) using sediment quality assessment indices. The average concentration of trace metals in the sediments exceeded the crustal abundance suggesting sources other than natural in origin. Additionally, the trace metals profile may be a reflection of socio-economic development in the vicinity of Sundarban which further attributes trace metals abundance to the anthropogenic inputs. A total of eleven surficial sediment samples were collected along a vertical transect along the freshwater-saline water gradient. The sediment samples were digested using EPA 3051 method and were analyzed on ICP-MS. Geo-accumulation index suggests moderately polluted sediment quality with respect to Ni and As and background concentrations for Al, Fe, Mn, Cu, Zn, Pb, Co, As, and Cd. Contamination factor analysis suggested low contamination by Zn, Cr, Co, and Cd, moderate by Fe, Mn, Cu, and Pb while Ni and As show considerable and high contamination, respectively. Enrichment factors for Ni, Pb, and As suggests high contamination from either biota or anthropogenic inputs besides natural enrichment. As per the three sediment quality guidelines, Fe, Mn, Cu, Ni, Co, and As would be more of a concern with respect to ecotoxicological risk in the Sundarban mangroves. The correlation between various physiochemical variables and trace metals suggested significant role of fine grained particles (clay) in trace metal distribution whereas owing to low organic carbon content in the region the organic complexation may not be playing significant role in trace metal distribution in the Sundarban mangroves.

A baseline study of levels of mercury, arsenic, cadmium and lead in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea.

This study is one of several baseline studies that will provide basic and reliable information about the content of undesirable substances in important species of fish caught in Norwegian waters. Concentrations of metals in the muscle and liver of more than 800 Northeast Arctic cod caught at 32 sites in the Barents Sea are reported. The highest concentration of both mercury in the muscle and cadmium in the liver was found in cod caught in the western part of the Barents Sea, while the highest concentration of total arsenic was found in cod from the eastern part. The arsenic concentrations varied greatly among individual fish, ranging from 0.3 to 170 mg kg(-1) wet weight in the muscle. Such high levels of total arsenic have never previously been reported in any fish, and the primary factor for these high concentrations is likely to be the shrimp in the cod diet.

Aseptic loosening of pedicle screw as a result of metal wear debris in a pediatric patient.

STUDY DESIGN: This is a case report. OBJECTIVE: To report a case of soft-tissue reaction to wear debris and osteolysis around a pedicle screw after posterior spine fusion in a pediatric patient. SUMMARY OF BACKGROUND DATA: Posterior spine fusion with instrumentation is a standard procedure for stabilization and curve correction in patients with scoliosis. Late operative site pain accounts for the highest frequency of reoperation. Debris accumulation for steel and titanium constructs occurs at the pedicle screw-rod junction. Cellular reaction to metal wear may be responsible for osteolysis and aseptic loosening around spinal implants. METHODS: A 14-year-old male patient with neurofibromatosis and right thoracic scoliosis of 50° underwent posterior spine fusion from T2 to T10. The postoperative course was complicated by continuous pain, and imaging studies demonstrated hardware failure, requiring a revision and subsequent development of a perihilar opacity of unknown origin. Further studies demonstrated hypermobility with adjacent soft-tissue reactivity and inflammation surrounding the right T5 transpedicle screw. RESULTS: After hardware removal, the patient's recovery was uneventful. Six months later, a repeated computed tomographic scan demonstrated resolution of the previously described soft-tissue mass and a satisfactory fusion of the thoracic spine. CONCLUSION: Metal wear debris can form in pediatric patients during the healing process after spinal fusions or when pseudarthrosis is present. Clinically, this manifests as back pain with a possible aseptic inflammatory abscess. Hardware removal can achieve resolution of symptoms and regression of inflammation.