Presence Of Bone Graft Research Articles

Influence of screw to joint distance on articular subsidence in tibial-plateau fractures.

Tibial-plateau fractures with depressed osteochondral fragments have a high incidence of articular subsidence post reduction. Locking plates aim to prevent this via 'raft' screws below the subchondral bone. However, differences in plate design and patient anatomy result in variability of screw position in relation to the fragments they are designed to support. We evaluate the effect of screw placement and articular subsidence with this fracture pattern. A retrospective cohort study of operatively treated tibial-plateau fractures with free osteochondral fragments was performed to determine if screw placement was correlated with articular subsidence. Primary outcome was the relationship between screw to joint distance and articular subsidence. Secondary outcomes were whether bicortical fixation, presence of bone graft, fracture characteristics and patient age was correlated with articular subsidence. Sixty-eight of 309 tibial-plateau fractures had depressed osteochondral fragments (22%). The average thickness of these fragments was 10.2 mm. Fractures with raft screws placed closer to the joint than the thickness of the osteochondral fragment were less likely to subside (1.8 versus 3.4 mm; P = 0.02). The proportion of fractures with no radiographic subsidence was also greater in this cohort versus fractures with distal screw placement (33% versus 8%; P = 0.02). Articular comminution (P = 0.04) and female patients aged over 65 years (P = 0.03) were associated with increased articular subsidence. Fractures fixed with screws closer to the joint than the thickness of the osteochondral fragment were correlated with less articular subsidence. The 'screw-joint distance' may help guide screw placement intra-operatively.

BAG-S53P4 as bone graft extender and antimicrobial activity against gentamicin- and vancomycin-resistant bacteria.

To evaluate the suitability of bioactive glass (BAG)-S53P4 as a bone-graft extender for large bony defect filling in bone and joint infection. Antimicrobial activity of BAG-S53P4 against clinically relevant strains isolated from bone and joint infections was evaluated by means of time-kill curves in presence of bone graft. Furthermore, the susceptibility to BAG of strains resistant to vancomycin and gentamicin was assessed. Though attenuated, BAG maintains a good in vitro antimicrobial activity in presence of human body fluids and tissues contained in bone graft, with the exception of Enterococcus faecalis. BAG-S53P4 is a suitable bone substitute that can be used as an extender with autologous bone graft to promote better fusion and healing.

Effects of mechanical loading patterns, bone graft, and proximity to periosteum on bone defect healing

The goal of this study is to elucidate whether mechanobiological factors, including mechanical loading patterns, presence of bone graft, and proximity to the periosteum, correlate to de novo tissue generation and healing in critical sized long bone defects, which are enveloped by periosteum in situ and are bridged at 16 weeks, in sheep femora. Quantitative histomorphometric measures of defect cross sections show that, along the axis least able to resist bending loads (minor centroidal axis, CA), bone laid down in the first two weeks after surgery exhibits more mineralization albeit less total area compared to bone along the axis most able to resist bending loads (major CA). Similarly, areas of the cross section along the minor CA show a higher degree of perfusion albeit less total area of perfusion compared to bone along the major CA. Furthermore, proximity to the periosteal niche, in conjunction with the presence of bone graft and predominant loading patterns, relates significantly to the radial distribution of early bone apposition and perfusion of bone at 16 weeks after surgery (linear regression with R2>0.80). In the absence of graft, early bone density is relatively evenly distributed in the defect zone, as is the intensity of perfused tissue. As measured by a steeper average slope in intensity of fluorochrome (new bone) distribution between the periosteum and the IM nail, the presence of bone graft retards initial bone formation in the defect zone and is associated with less evenly distributed tissue perfusion (steeper slope) persisting 16 weeks after surgery. Finally, although the mean area of bone resorption is not significantly different within or between groups defined by the presence of graft and/or mechanical loading patterns in the defect zone, the mean area of infilling resorption spaces is significantly higher in areas of the defect zone least able to resist bending (minor CA) but is not significantly related to the presence of bone graft. To our knowledge, the use of the major and minor centroidal axes to relate prevailing mechanical loading patterns to area and density of early bone generation in bone defects has not been reported prior to this study and may provide a new means to assess structure–function relationships in de novo bone generation and healing of bone defects.

The Fate of Pelvic Osteolysis After Reoperation; No Recurrence With Lesional Treatment

Twenty-three hips (21 patients) with 30 pelvic osteolytic lesions underwent reoperation and were observed prospectively for 25 to 74 months (average, 40 months) to assess the fate of pelvic osteolysis after reoperation. The average radiographic dimensions of the lytic lesions were 2.4 x 1.9 cm with the largest lesion measuring 7 x 5 cm. The porous ingrowth acetabular component shell had been left in situ in 15 hips and had been revised in eight. There was no difference in the average lesional size for hips with revised shells compared with those with unrevised shells. In cases where the shell was left in situ, the osteolytic lesions were curetted by working around the component perimeter or through holes in the shell. In 18 hips the bone defect(s) were grafted with autograft or allograft. Regardless of the management of the acetabular shell or the absence or presence of bone graft, none of the osteolytic lesions have progressed. Twenty-six of the 30 lesions have increased radiographic density. All acetabular components remain radiographically well fixed. There were no new osteolytic lesions. All hips were functioning well, and none have required subsequent reoperation for any reason. There was a statistically significant reduction in the operative time and the amount of blood loss when the acetabular component was not revised. It does not appear necessary to remove a well fixed and well positioned cementless acetabular component for the treatment of pelvic osteolysis. Debridement of periarticular inflammatory tissue and lesional curettage, either with or without bone graft, is effective in managing this type of bone loss. Revision of the acetabular component shell was associated with a significant increase in operative time and blood loss. These results support routine radiographic evaluation after total hip arthroplasty to monitor the development of osteolysis. On the basis of this experience, the authors recommend lesional treatment of progressive pelvic osteolysis to avoid more difficult surgery and minimize patient morbidity.

Transcervical Fractures of the Hip Treated With the Bateman Bipolar Prosthesis

Eighty-seven elderly patients with subcapital hip fractures treated by Bateman bipolar hip hemiarthroplasty were reviewed using Harris hip scores at a minimum of 24 months after their index operation. The complication rate was comparable to other reported series. The degree of pain was lower than a comparable unipolar arthroplasty series. Neither the relationship of the stem to the canal nor the presence of bone graft in the stem fenestration had any correlation to the patients' function. Femoral cups too large for the acetabulum predictably required another operation, but normal or small cup relationships had no prognostic correlation.