Aseptic loosening is considered relatively common complication of hip joint replacements. It is usually considered a long-term complication and is often considered as the most common complication 3.
Aseptic loosening can occur as a result of inadequate initial fixation, mechanical loss of fixation over time, or a biological loss of fixation caused by particle-induced osteolysis surrounding the implant.
The causes of particle accumulation vary from implant interface wear, micromotion occurring in response to corrosion, oxidative reactions, and minor pathogen contamination. The initial response to particulate debris can include a subtle inflammatory response, which becomes more pronounced as osteolysis progresses. This inflammatory environment provokes a cellular response which is characterised by elevated levels of secreted factors such as TNF, RANKL, IL-6, IL-1, and IL-11.
A peri-implant lucency of greater than 2 mm or progressive change is considered a concerning feature. Stress views may show an interval change in position. The loosening is not lined by sclerosis. The features may include:
- medial migration of cement and cup mass
- change in inclination of the cup
- 1. Abu-Amer Y, Darwech I, Clohisy JC. Aseptic loosening of total joint replacements: mechanisms underlying osteolysis and potential therapies. Arthritis Res. Ther. 2007;9 Suppl 1 (Suppl 1): S6. doi:10.1186/ar2170 - Free text at pubmed - Pubmed citation
- 2. Stumpe KD, Nötzli HP, Zanetti M et-al. FDG PET for differentiation of infection and aseptic loosening in total hip replacements: comparison with conventional radiography and three-phase bone scintigraphy. Radiology. 2004;231 (2): 333-41. doi:10.1148/radiol.2312021596 - Pubmed citation
- 3. Ince A, Rupp J, Frommelt L et-al. Is "aseptic" loosening of the prosthetic cup after total hip replacement due to nonculturable bacterial pathogens in patients with low-grade infection?. Clin. Infect. Dis. 2004;39 (11): 1599-603. doi:10.1086/425303 - Pubmed citation
- 4. The adult hip. LWW. ISBN:078175092X. Read it at Google Books - Find it at Amazon
- 5. Parvizi J, Suh DH, Jafari SM et-al. Aseptic loosening of total hip arthroplasty: infection always should be ruled out. Clin. Orthop. Relat. Res. 2011;469 (5): 1401-5. doi:10.1007/s11999-011-1822-1 - Free text at pubmed - Pubmed citation
- 6. Bordini B, Stea S, De Clerico M et-al. Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis. BMC Musculoskelet Disord. 2007;8 (1): 69. doi:10.1186/1471-2474-8-69 - Free text at pubmed - Pubmed citation