RESUMO
Metallosis, defined as the presence of free metal particles in the tissue, including bone and soft tissue, is a rare phenomenon seen in orthopedic practice. It is more commonly seen in arthroplasty surgeries, but its occurrence in the presence of other metal implants is also well recognized. Multiple hypotheses are suggested to explain the genesis of metallosis, but it is traditionally believed that abnormal contact between the metal surfaces leads to abrasive wear causing the release of metal particles into the surrounding tissue eliciting foreign body reactions from the body's immune system. The consequences can be local effects, which can be asymptomatic soft tissue lesions, or lead to significant osteolysis, tissue necrosis, joint effusion, and large soft tissue masses, causing secondary pathological effects. The systemic distribution of these metal particles can also contribute to the clinical picture. The literature contains multiple case reports of metallosis following arthroplasty surgeries, but there is limited information on metallosis resulting from osteosynthesis of fractures. In this review, we are presenting our experience with a few patients who developed nonunion following the index surgeries and on revision were found to have metallosis as well. It is difficult to postulate whether metallosis was contributory to the nonunion or the other way around or whether the occurrence of nonunion in face of metallosis was a pure coincidence. Additionally, one of our patients had a positive intraoperative culture, further complicating the picture. In addition to the case series, we present a succinct review of the literature on metallosis found in previous studies.
RESUMO
Introduction Calcium-sulfate-hydroxyapatite bioceramics have been widely used as void fillers in bone. However, their effectiveness as void fillers in core decompression for osteonecrosis of the femoral head (ONFH) in preventing femoral head collapse prevention has limited evidence. The current study investigates the effectiveness of calcium-sulfate-hydroxyapatite bioceramics as a void filler in the core decompression procedure for ONFH. Methods We retrospectively reviewed the clinical and radiological records of ONFH patients that underwent core-decompression using either autologous iliac crest cancellous bone graft or calcium-sulfate-hydroxyapatite bioceramic paste as void fillers with at least one-year follow-up. The primary outcome of this study was the radiological progression of collapse in the last available standard anteroposterior (AP) radiographs of the hip. The collapse progression was compared between the two groups based on void fillers. Results This study included patient records with 44 hip joints that underwent core decompression. There were five female and 33 male patients. The mean age was 29.1±6.3 years. The mean follow-up duration was 21.4±3.4 months. No significant differences in collapse progression were observed between the two groups based on void fillers. Conclusion The use of calcium-sulfate-hydroxyapatite as a void filler in core decompress for ONFH is not superior to the autologous cancellous bone in terms of collapse prevention and mechanical support. Further modifications in the core decompression techniques and well-planned prospective studies would help establish sound recommendations.
