Incidence of postoperative nausea and vomiting is not increased by combination of low concentration sevoflurane and propofol compared with propofol alone in patients undergoing laparoscopic gynecological surgery.

BACKGROUND: The incidence of postoperative nausea and vomiting (PONV) is higher in patients receiving volatile anesthetics than those receiving total intravenous anesthesia (TIVA) with propofol. However, it is unclear whether its incidence is increased when a low concentration of sevoflurane is used in combination with propofol. METHODS: This prospective, randomized, controlled trial enrolled women undergoing laparoscopic gynecological surgery. Patients were randomly assigned to receive general anesthesia either with propofol alone (group P) or with 0.8% sevoflurane and propofol (group SP, n = 36, each group) for maintenance of anesthesia. The incidence of PONV and the number of patients who required antiemetics were compared. RESULTS: There were no differences in the incidence of PONV and the number of patients who required antiemetics between the P and SP groups. CONCLUSIONS: A combination of 0.8% sevoflurane and propofol to maintain anesthesia does not increase the incidence of PONV compared with TIVA with propofol. TRIAL REGISTRATION: UMIN-CTR UMIN000023647 , registered 14 August 2016.

Histologic analysis of allograft mixed with hydroxyapatite-tricalcium phosphate used in revision femoral impaction bone grafting.

Failed total hip arthroplasty (THA) often is accompanied by loss of bone stock. In cases in which revision THA becomes necessary, adequate stabilization of the implant can be difficult because of the bone loss. Bone can be reconstructed by using tightly packed morselized cancellous bone graft in combination with a cemented stem. However, worldwide availability of human bone is limited, and risks such as infection and antigenicity are associated with the use of allogeneic bone. These risks have led to the development of synthetic bone graft extenders. The objective of impaction bone grafting is to achieve stability of an implant and subsequently allow the restoration of living bone stock. To reduce the amount of allograft consumed, a mixture of morselized allograft and hydroxyapatite-tricalcium phosphate was used for impaction grafting in a series of 15 patients. In 2 patients who required re-revision arthroplasty, the areas of impacted graft were analyzed histologically. The results showed a complex mixture of residual hydroxyapatite-tricalcium phosphate, necrotic bone (graft), viable bone, and fibrous tissue. Although several pre-clinical studies have described the expansion of allograft with synthetic materials, this article represents the first description of histologic findings in human femoral impaction grafting with a combination of allograft and hydroxyapatite-tricalcium phosphate.

Ambulatory physical activity, disease severity, and employment status in adult women with osteoarthritis of the hip.

OBJECTIVE: To measure ambulatory physical activity and determine associations between physical inactivity and joint function, gait function, disease severity, and employment status in adult women with hip osteoarthritis (OA) living in the community. METHODS: Sixty-five adult women with hip OA were recruited from an outpatient clinic. Ambulatory physical activity was measured using an activity monitor based on an accelerometer over 7 days, which estimated step counts, net energy expenditure, and time spent in activity by acceleration intensity. The Harris hip score, walking speed, and radiographic stage were assessed for joint function, gait function, and disease severity, respectively. Employment status was classified into unemployed and employed (sitting occupations and standing/walking occupations). RESULTS: More than 40% of patients were classified as inactive, with less time spent in moderate-intensity activity (median 5.6 vs 22.9 min/day) compared with their counterparts. Employment status and the presence or absence of stage 4 (endstage) arthritis were independently associated with activity classification, and there was an interaction between these 2 variables; i.e., although stage 4 arthritis was associated with inactivity in patients who were unemployed, it bore no relationship in patients who were employed. CONCLUSION: A significant proportion of adult women with hip OA were physically inactive, with a lack of moderate-intensity activity. The possible interaction between endstage OA and employment status requires further study to determine whether being at work negates the adverse effects of endstage OA or whether higher functioning due to physical activity enables patients with endstage OA to be employed.

Impaction bone grafting with hydroxyapatite: increased femoral component stability in experiments using Sawbones.

BACKGROUND: Substantial bone loss and bone defects increase the amount of allografting required in hip revision surgery. Thus, the use of a synthetic material to limit the amount of allograft tissue required for impaction grafting is desirable. We evaluated the potential of hydroxyapatite (HA) mixtures to provide initial mechanical stability to a polished tapered femoral stem. MATERIAL AND METHODS: We determined the initial stability of a polished tapered femoral stem after reconstructing a cavitary femoral bone defect by impaction bone grafting with cement in Sawbones composite femurs. Three types of graft material were tested for their ability to improve initial rotational stability. The graft materials investigated were pure allograft, a mixture of 50% allograft and 50% hydroxyapatite (HA), and pure HA. RESULTS: We found a statistically significant difference between the three groups as regards torsional micromotion and failure load. INTERPRETATION: Our findings suggest that reconstruction of femoral bone defects with pure HA or a mixture of allograft and HA provides adequate initial stability for femoral revision arthroplasty using impaction grafting.

Effect of cyclic mechanical stretch and titanium particles on prostaglandin E2 production by human macrophages in vitro.

Early implant instability has been proposed as a critical factor in the onset and progression of aseptic loosening and periprosthetic osteolysis in total joint arthroplasties. Previous in vitro studies have reported that macrophages stimulated with cyclic mechanical strain release inflammatory mediators. Little is known, however, about the response of these cells to mechanical strain with particles, which is often a component of the physical environment of the cell. We therefore studied the production of prostaglandin E(2) (PGE(2)), an important mediator in aseptic loosening and periprosthetic osteolysis in total joint arthroplasties, for human macrophages treated with mechanical stretch alone, titanium particles alone, and mechanical stretch and particles combined. A combination of mechanical stretch and titanium particles resulted in a statistically synergistic elevation of levels of PGE(2) compared with the levels found with either stretch or particles alone. Exposure of human macrophages to mechanical stretch with particles upregulated the expression of cyclooxygenase (COX)-2 mRNA but not COX-1 mRNA, this expression resulting in a 97-fold increase in PGE(2) production compared to the nonstimulated cells. The current study is the first to investigate the effects of mechanical stretch with particles on cultured macrophages and include an investigation of the time course of PGE(2) production and COX-2 mRNA expression. Our results suggest that, while mechanical strain may be one of the primary factors responsible for macrophage activation and periprosthetic osteolysis, mechanical strain with particles load may contribute significantly to the osteolytic potential of macrophages in vitro. The synergistic effect observed between mechanical stretch and particles could accelerate implant loosening and implies that reduction in either cyclic mechanical strain or wear debris load would lead to a reduction of osteolysis.

"Backside" polyethylene deformation in total knee arthroplasty.

The clinical importance of polyethylene deformation between the tibial insert and base plate ("backside") is unclear. We used a semiquantitative scoring system to compare clinical and radiographic factors with articular and backside deformation of 106 retrieved polyethylene tibial inserts. Backside deformation was associated with polyethylene thickness and type of locking mechanism. Deformation of the articular surface correlated with femoral osteolysis (P=.05). The mean backside deformation score was 33% greater for implants from patients with osteolysis than for implants from patients without osteolysis (P=.07). Our study may be biased based on the types of implants available for study, but for this group of implants, we cannot conclude with 95% certainty that backside polyethylene deformation was clinically important as a cause of periprosthetic osteolysis or implant loosening.

Histologic evaluation of human vertebral bodies after vertebral augmentation with polymethyl methacrylate.

STUDY DESIGN: Histologic documentation of vertebral bodies retrieved from human patients. OBJECTIVES: The purpose of this study is to illustrate the histologic findings of two cases in which vertebroplasty and/or kyphoplasty had been performed. SUMMARY OF BACKGROUND DATA: There are a number of controversies to vertebral augmentation, including the use of inflatable bone tamps, use of nonstandardized polymethylmethacrylate (PMMA) preparations, the extent and significance of thermal necrosis, any foreign body reaction, and cement extravasation. METHODS: Four vertebral bodies from two cases ranging from 1 month to 2 years after surgery were analyzed histologically. Microscope slides of retrieved vertebral bodies were reviewed with special reference for evidence of thermal necrosis, foreign body reaction, migration of cement, cement voids and fractures, and for the influence of the bone tamp on adjacent bone. RESULTS: The cancellous bone around the cement of the kyphoplasty specimen showed good density, suggesting that the tamping had displaced bone, essentially autografting the space around the cement. Bone immediately around the cement did not show extensive necrosis, but there were a few spicules of necrotic bone associated with creeping substitution, suggesting either thermal effect, the original fracture, or displacement of bone by the procedure. Foreign body giant cells and macrophages were identified in the fibrous membrane around the PMMA in all segments. These cells contained material consistent with cement particles and/or barium sulfate. Particles were also present within vascular spaces. CONCLUSIONS: To our knowledge, these cases are among the first published reports of human histology after vertebral cement augmentation and have implications concerning the nature of the surgical procedures as well as the material used for injection.

Reconstruction of the iliofemoral ligament with an artificial ligament for recurrent anterior dislocation of total hip arthroplasty.

An 86-year-old woman underwent 4 revisions of hip arthroplasty and showed good position of both acetabular and femoral components. This was confirmed by roentgenographic measurements in the prone position. However, poor anterior acetabular covering after posterior inclination of the pelvis associated with lumbar kyphosis was observed in the standing position. Therefore, we reconstructed the iliofemoral ligament using a Leeds-Keio ligament to prevent anterior dislocation. At the 12-month follow-up evaluation, hip stability was confirmed, and the hip showed no further dislocation.

Comparative evaluation of the osteoinductivity of two formulations of human demineralized bone matrix.

In the United States, demineralized bone matrix (DBM) is considered a transplantable tissue and therefore is regulated primarily by the American Association of Tissue Banks. Even though DBM is not subjected to the same regulations relative to performance claims as medical devices are, one would expect different processing methods might yield DBM preparations of different osteoinductive potential. The purpose of this study was to use an established athymic rat model to compare the osteoinductive properties of two commercially available human DBMs prepared using different methods but having essentially identical product claims. Sixteen female athymic rats were used to test equivalent volumes of two lots each of Grafton Putty (Osteotech, Inc., Eatontown, NJ), Osteofil (Regeneration Technologies, Inc., Alachua, FL), and rat DBM. At 28 days after implantation, qualitative and semiquantitative microscopy showed no significant differences in bone formation between the two lots from each source, but rat DBM produced significantly more bone than Grafton, which produced significantly more bone than Osteofil. Our results suggest that methods of graft processing may represent a greater source of variability than do differences among individual donors. Whether these differences relate to methods of demineralization, carrier, dose of DBM per volume, or to some other factor remains to be determined.

Histology of tissues within retrieved human titanium mesh cages.

STUDY DESIGN: Histologic documentation of contents within retrieved, failed human titanium mesh cages. OBJECTIVES: The purpose of this study is to describe the contents of a series of retrieved, clinically failed titanium mesh cages from human patients. SUMMARY OF BACKGROUND DATA: The use of interbody fusion cages is gaining rapid acceptance, but there is little histologic documentation of tissue within retrieved cages. METHODS: Eleven Titanium Surgical Mesh Cages (Harms; DePuy AcroMed, Raynham, MA) retrieved from 10 patients were histologically analyzed. Indications for cage retrieval included failed fusion or failed fusion with instrumentation failure. The cages had been in situ from 2 to 47 months. Histologic sections were reviewed qualitatively, and the approximate percent of area in the cage occupied by viable bone, necrotic bone, fibrocartilage, hyaline cartilage, fibrous tissue, and bone graft substitute was visually estimated. Particles of metal debris were estimated by a semiquantitative scoring system. RESULTS: All cages except one showed evidence of vascular ingrowth and areas of histologically viable bone, representing incorporating bone graft. At least a few particles of debris were present in 9 of 11 cages. Fibrocartilage of probable intervertebral disc origin ranged from 0% to 70% of the available area. Several cages contained small seams of fibrocartilage connecting segments of bone in a pattern that suggested a response to motion. CONCLUSIONS: Mean viable bone area within 11 retrieved, human titanium mesh cages was approximately 31%. Seams of fibrocartilage within the cages may represent tissue differentiation in response to bending or compressive load.