Bone Health

A case of Total Hip Arthroplasty infection with Staphylococcus aureus co-infected with Salmonella choleraesuis was treated with two-stage exchange and administration of vancomycin and ciprofloxacin. No signs of re-infection have appeared 14 months after surgery. Cases of Salmonella infection of hip prostheses are quite rare, with only a handful of reports in the literature.

Wheeless Textbook of Orthopaedics Discussion: - most common complication in total hip arthroplasty and most common cause of component failure; - osteolysis is a time dependent process which arises from inflammatory reaction against polyethylene particulate debris; - patho-biology: - osteolysis is mediated primary by macrophages (fibroblasts and endothelial cells also play a role); - these cells are activated by wear debris (primarily polyethylene, but also metal and polymethylmethacrylate debris); - chemical mediators include: interleukin-1 (bone-resorbing cytokine) and tumor necrosis factor; - in the report by Yanming Bi et al (JBJS 2001), the authors present study showed that titanium particles induced both murine marrow cells and human peripheral blood monocytes to produce factors that stimulated osteoclast differentiation; - mean increase in osteoclast differentiation was 29.3 ± 9.4-fold. - they showed that titanium particles stimulate in vitro bone resorption primarily by inducing osteoclast differentiation;

In 2004, 234,000 total hip replacements (THRs) and 478,000 total knee replacements (TKRs) were performed in the United States. Treatment of the diseased hip or knee joint does not end with surgical replacement. The ultimate goal is ensuring pain-free function of the joint to improve the patient's quality of life (QOL). Postoperative rehabilitation is of the utmost importance.
Synonyms and related keywords: total joint arthroplasty, total hip replacement, total hip arthroplasty, total knee replacement, total knee arthroplasty, cemented joint replacement, cemented joint arthroplasty, ingrowth joint replacement, ingrowth joint arthroplasty, cementless joint replacement, cementless joint arthropathy, primary joint replacement, primary joint arthroplasty
Rasul & Wright 2007

David S. Hungerford, MD Professor, Orthopaedic Surgery Johns Hopkins University January, 2006 Baltimore, Maryland
The history of total joint replacement has been about basically three things: Firstly, finding the right materials that can function safely and effectively as biomaterials in long-term implants. Early attempts have used such disparate materials as ivory, cellophane, fascia lata, chromacized pig bladder, skin, other plastics, glass and metals in various forms. The interface between the implant and bone, termed the fixation, has been the second issue. Press-fit, cement and bone ingrowth/ongrowth have been the principal approaches that have been tried. Finally, the bearing surface has been an issue since the single side replacement was abandoned early on in favor of 'total' replacement.

Abstract:Uncemented short-length diaphyseal segmental replacement prosthesis fixation - Finite element analysis and long-term results
Journal of Orthopaedic Research Volume 23, Issue 5 , Pages 1065 - 1072 Published Online: 1 Jan 2006
Conclusions: A short-length fixation system based on intramedullary anchorage of segmental replacement endoprostheses would possibly support physiologic adaptive processes more than fixation over the full length of the stem.

Objective: Increased wait times for total joint arthroplasty (TJA) are a concern nationally and provin- cially. Additionally, the number of patients requiring revision of their initial TJA is increasing. The pur- pose of this study was to evaluate the wait times and impact of waiting for revision TJA.
Conclusion:Wait- ing> 6 months for revision hip arthroplasty resulted in significant increases in pain and physical disability.
Waiting for hip revision surgery: the impact on patient disability Aileen M. Davis, PhD;*†‡Zoe Agnidis, MScPT;§Elizabeth Badley, PhD;†‡J. Roderick Davey, MD;¶‡ Amiram Gafni, PhD;**Jeffrey Gollish, MD;††‡Nizar N. Mahomed, MD, DPhil;¶‡Khaled J. Saleh, MD;‡‡ Emil H. Schemitsch, MD;§§‡John Paul Szalai, PhD;††‡James P. Waddell, MD;§§‡Allan E. Gross, MD§‡