MODIFIED SURGICAL TECHNIQUE TO REDUCE BON E-MARROW RELEASE DURING TOTAL KNEE REPLACEMENT

In the literature 20 cases of fat embolism syndrome (FES) after total knee replacement (TKR) are reported; 16 cases had cemented hinged TKR and 4 resurfacing TKR. Initially, it was believed that the bone cement was responsible for the FES. Since then, however, Fahmy et al. have p ublished extraordinary data, demonstrating the causal relationship bet ween increased intramedullary pressure (IMP) during the insertion of t he intramedullary rod (IR) and cardiorespiratory deterioration. The in dustry responded by developing a fluted IR, disregarding the overdrill ing in the distal femur required by Fahmy. In the first part of this p aper clinically manifest FES cases after resurfacing TKR are reported. In the second part of the study the conventional surgical technique i s compared with a modified technique, which focuses on a reduction of bone-marrow release into the circulation. In the conventional and the modified group, IRs with and without; flutes were compared. It was sho wn that only the opening of the intramedullary canal and insertion of the IR generated relevant IMP peaks during implantation of resurfacing TKR. When compared with the conventional surgical technique, the modi fied technique revealed significantly lower IMPs, and in neither group was a difference demonstrated between the IR with or without flutes. In 4 patients (2 conventional, 2 modified) transesophageal echocardiog raphy (TEE) was performed for detection of bone-marrow release into th e circulation. In the two patients operated on conventionally, TEE sho wed a markedly higher bone-marrow release than in the patients with mo dified operations. In conclusion, we recommend the presented modified surgical technique in order to reduce bone-marrow release into the cir culation.