Femoral impaction grafting

Cemented Revision Hip Arthroplasty With Femoral Impaction Bone Grafting

Long-stemmed uncemented implants are commonly used during revision hip arthroplasty but may be difficult to re-revise. Impaction bone grafting allows for the use of a shorter cemented stem during revision hip arthroplasty and may restore bone stock in patients with substantial femoral defects. Femoral impaction bone grafting is particularly beneficial in younger patients, who are more likely to require additional revision procedures in the future. The surgical technique used at our institution includes improvements to previous methods including the use of modular tamps and nonirradiated, size-profiled bone graft.

Effect of synthetic bone replacement material of different size on shear stress resistance within impacted native and thermodisinfected cancellous bone: an in vitro femoral impaction bone grafting model

Antibiotic carrier particles of variable size might influence mechanic properties within impacted thermodisinfected and native cancellous bone different. Herafill®G containing calciumsulfate and calciumcarbonate provides high local concentrations of gentamicin being important for revision surgery in infected joint replacements. Native and thermodisinfected cancellous bone derived from 6 to 7 months old piglets was used for in vitro impaction bone grafting and supplemented each with Herafill®G granules of two different sizes. Micromovement of implants related to shear force was measured in 29 specimens distributed in 6 groups. Thermodisinfected cancellous bone revealed a significant higher shear force resistance than native bone with a mean difference of 423.8 mdeg/Nm (p < 0.001) ranging within 95% confidence interval from 181.5 to 666.0 mdeg/Nm. Adding small granules to thermodisinfected bone did not reduce shear force resistance significantly since adding large granules to native bone improved it by 344.0 mdeg/Nm (p < 0.003). Shear force resistance was found higher at the distal region of the implant compared to a proximal point of measurement throughout all specimens. Less impaction impulses were necessary for thermodisinfected bone. Thermodisinfected cancellous bone might achieve a higher degree of impaction compared with native bone resulting in increased resistance against shear force since impaction was found increased distally. Supplementation of thermodisinfected bone with small granules of Herafill®G might be considered for application of local antibiotics. Large granules appeared more beneficial for supplementation of native bone. Heterogeneity of bone graft and technical aspects of the impaction procedure have to be considered regarding the reproducibility of femoral impaction bone grafting.

Comparison of bone marrow component removal from processed femoral head bone from living and deceased donors: presence of geodes in living donor bone can prevent maximum removal of marrow components

NHS Blood and Transplant Tissue and Eye Services banks and issues, cut, shaped and washed bone from deceased donors. The bone is cut/shaped prior to washing and then processed to remove up to 99.9% of blood, bone marrow and associated cells. The processed bone is then sterilised by gamma irradiation with or without a freeze-drying step. Removal of donor blood and bone marrow has been reported to aid incorporation of allograft bone without affecting the biomechanical properties of the bone. However, cut and shaped bone is not suitable for some orthopaedic procedures and some orthopaedic surgeons do not wish to use irradiated bone. Therefore, Tissue and Eye Services have also developed a method for washing intact femoral head bone, from living and deceased donors. We have observed that processing of intact femoral head bone does not always result in removal of 99% (or above) of marrow components and can be as low as 93% removal. We have examined washed femoral head bone and found the presence of internal fluid-filled cysts within subchondral cancellous bone in bone from living donors. The cysts have been identified as geodes and we suggest that these geodes may be responsible for the reduction in bone marrow component removal in living donor bone during processing.