While component malposition remains a major short and long term problem associated with total hip arthroplasty, enhanced technologies such as navigation and robotics have not yet been widely adopted. Both expense and increased OR time can be obstacles to adoption. The current study assesses the effect of the use of a smart mechanical navigation system on surgery time in total hip arthroplasty. 514 consecutive primary total hip arthroplasties were performed by a single surgeon from January 1, 2015 through March 31, 2016. Of these, 40 were performed using a smart mechanical navigation system (the HipXpert System, Surgical Planning Associates Inc., Boston, Massachusetts) and 474 were performed without navigation. The patients were not randomized. Incision to closure time (surgery time) was recorded for each procedure. A two tailed t-test was performed to assess statistical significance.Introduction
Patients and Methods
Surgical reconstruction of the injured Anterior Cruciate Ligament (ACL) is an effective solution to knee instability, but not all grafts incorporate well. The biological environment in the knee that controls graft integration is not well understood, and this study aims to fill that gap as the first step towards a translational approach to optimise outcomes. Over two stages, tissue samples and knee fluid samples were harvested from patients undergoing ACL reconstruction. These samples were cultured and stored to allow batch analysis for a variety of cytokines, growth factors and collagenases. Stage 1 (n=14) identified the presence of specific pro-inflammatory cytokines, growth factors and latent collagenase. Information gathered allowed a more targeted approach to be used in stage 2 (n=18). Stage 2 data from tissue cultures suggest that collagenase activity peaks later than 6 hours post-op. The relationships between collagenase activity and levels of TNF-alpha, IL-1beta and bFGF are of potential interest, and the profiles of patients will be compared with longer term follow-up data to determine any effects on outcomes. Further detailed assessment of the biology of ACL graft incorporation is required, but these preliminary data have clarified some of the details worthy of further study.
Unlike most other tumours, myeloma causes bone destruction without an osteoblastic reaction; we tried to assess whether myeloma secretes a humoral factor that inhibits osteoblasts. Human bone-derived cells were either co-cultured with myeloma cells, or cultured in medium conditioned by myeloma cells. Bone-derived cell growth was measured by cell counts and by uptake of tritiated thymidine (3H-Tdr); growth was inhibited when cultured in medium conditioned by myeloma cells and some inhibition was seen when the bone-derived cells were co-cultured with myeloma cells. The inhibiting effect was dose-dependent and also dependent upon the density of the myeloma cells conditioning the medium. The results of our study suggest that myeloma secretes an osteoblast inhibiting factor of less than 50,000 Dalton molecular weight.
