Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, James Ninomiya, MD, MS, lead author of the September 21, 2016 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the nearly 70 studies summarized in the Specialty Update.
–A meta-analysis found no differences in short- and medium-term implant survivorship among the following three bearing combinations used in THA patients younger than 65 years of age: ceramic on ceramic, ceramic on highly cross-linked polyethylene, and metal on highly cross-linked polyethylene.1
Insight into Aseptic Loosening
–Pathogen-associated molecular patterns (“endotoxins”) on particulate wear debris may be partially responsible for aseptic loosening. An in vitro/in vivo study found that macrophages that did not express the pathogen-associated molecular pattern receptor called TIRAP/Mal had significantly diminished secretion of inflammatory proteins. Patients with a genetic polymorphism suppressing that receptor exhibited decreased osteolysis during in vivo experiments. This suggests that some patients may be genetically more prone to aseptic loosening.
THA in Patients with RA
–A systematic review/meta-analysis of patients who were and were not taking a TNF-α inhibitor for rheumatoid arthritis prior to hip replacement found that those taking the drug had an increased risk of perioperative infection, with an odds ratio of 2.47.2 These results suggest that in order to decrease the risk of perioperative infections, it may be prudent to discontinue these drugs in advance of proposed joint replacement surgery.
Delaying THA for Femoral Head Osteonecrosis
–A systematic review/meta-analysis of patients with femoral head osteonecrosis concluded that injection of autologous bone marrow aspirate containing mesenchymal stem cells during core decompression was superior by a factor of 5 to core decompression alone in preventing collapse of the femoral head and delaying conversion to THA.3 This information may lead to new treatment paradigms for osteonecrosis.
Preventing Post-THA Dislocations
–A systematic review/meta-analysis that included more than 1,000 patients who underwent THA with a posterior or anterolateral approach found similar dislocation rates among those who were and were not given post-procedure restrictions in motion or activity.4 This suggests that the use of traditional hip precautions may not be necessary, and in fact may impede the rate of recovery following joint replacement surgery.
- Wyles CC, Jimenez-Almonte JH, Murad MH, Norambuena-Morales GA, Cabanela ME, Sierra RJ, TrousdaleRT. There are no differences in short- to mid-term survivorship among total hip-bearing surface options: a network meta-analysis. Clin Orthop Relat Res. 2015 Jun;473(6):2031-41. Epub 2014 Dec 17.
- Goodman SM, Menon I, Christos PJ, Smethurst R, Bykerk VP. Management of perioperative tumour necrosis factor α inhibitors in rheumatoid arthritis patients undergoing arthroplasty: a systematic review and meta-analysis. Rheumatology (Oxford). 2016 Mar;55(3):573-82. Epub 2015 Oct 7.
- Papakostidis C, Tosounidis TH, Jones E, Giannoudis PV. The role of “cell therapy” in osteonecrosis of the femoral head. A systematic review of the literature and meta-analysis of 7 studies. Acta Orthop. 2016 Feb;87(1):72-8. Epub 2015 Jul 29.
- Van der Weegen W, Kornuijt A, Das D. Do lifestyle restrictions and precautions prevent dislocation after total hip arthroplasty? A systematic review and meta-analysis of the literature. Clin Rehabil. 2016 Apr;30(4):329-39. Epub 2015 Mar 31.