BACKGROUND: Due to degradation and metal dissolution during articulation of metal joint replacements the chemical periprosthetic environment may change. The aim was to establish whether metal replacements cause the local changes in pH and elevated metal concentrations. METHODS: pH was measured on samples from 167 patients: native hip and knee osteoarthritic joints, joints with hip and knee replacements revised for aseptic or septic reasons. pH of synovial fluid and periprosthetic tissue was measured perioperatively using a microelectrode and pH indicator papers for removed metal components. Metal concentrations were measured in 21 samples using inductively coupled plasma mass spectrometry. RESULTS: The mean pH value of synovial fluid at native osteoarthritic joints (n = 101) was 7.78 ± 0.38. The mean pH value of synovial fluid at revision aseptic operation (n = 58) was 7.60 ± 0.31, with statistically significant difference (p = 0.002) compared to native osteoarthritic joints. The mean pH value of synovial fluid at revision septic operation (n = 8) was 7.55 ± 0.25, with statistically significant difference (p = 0.038) compared to native osteoarthritic joints. Measurements in tissue and at stems were not reliable. In the majority of samples taken at revision increased levels of cobalt and chromium were measured. CONCLUSION: A small but statistically significant difference was observed in the pH of synovial fluid between natural joints with degenerative diseases and joints treated with metal replacements. Based on the increased metal levels we expected the value of pH to be lower, but the influence of metal ions is counteracted by the buffering capacity of human body.
BACKGROUND: Due to degradation and metal dissolution during articulation of metal joint replacements the chemical periprosthetic environment may change. The aim was to establish whether metal replacements cause the local changes in pH and elevated metal concentrations. METHODS: pH was measured on samples from 167 patients: native hip and knee osteoarthritic joints, joints with hip and knee replacements revised for aseptic or septic reasons. pH of synovial fluid and periprosthetic tissue was measured perioperatively using a microelectrode and pH indicator papers for removed metal components. Metal concentrations were measured in 21 samples using inductively coupled plasma mass spectrometry. RESULTS: The mean pH value of synovial fluid at native osteoarthritic joints (n = 101) was 7.78 ± 0.38. The mean pH value of synovial fluid at revision aseptic operation (n = 58) was 7.60 ± 0.31, with statistically significant difference (p = 0.002) compared to native osteoarthritic joints. The mean pH value of synovial fluid at revision septic operation (n = 8) was 7.55 ± 0.25, with statistically significant difference (p = 0.038) compared to native osteoarthritic joints. Measurements in tissue and at stems were not reliable. In the majority of samples taken at revision increased levels of cobalt and chromium were measured. CONCLUSION: A small but statistically significant difference was observed in the pH of synovial fluid between natural joints with degenerative diseases and joints treated with metal replacements. Based on the increased metal levels we expected the value of pH to be lower, but the influence of metal ions is counteracted by the buffering capacity of human body.
Authors: Jacek Siódmiak; Piotr Bełdowski; Wayne K Augé; Damian Ledziński; Sandra Śmigiel; Adam Gadomski Journal: Molecules Date: 2017-09-04 Impact factor: 4.411
Authors: Shan Huang; Kristina A Thomsson; Chunsheng Jin; Sally Alweddi; André Struglics; Ola Rolfson; Lena I Björkman; Sebastian Kalamajski; Tannin A Schmidt; Gregory D Jay; Roman Krawetz; Niclas G Karlsson; Thomas Eisler Journal: Sci Rep Date: 2020-03-06 Impact factor: 4.379